These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Nuclear driven water decomposition plant for hydrogen production  

NASA Technical Reports Server (NTRS)

The conceptual design of a hydrogen production plant using a very-high-temperature nuclear reactor (VHTR) to energize a hybrid electrolytic-thermochemical system for water decomposition has been prepared. A graphite-moderated helium-cooled VHTR is used to produce 1850 F gas for electric power generation and 1600 F process heat for the water-decomposition process which uses sulfur compounds and promises performance superior to normal water electrolysis or other published thermochemical processes. The combined cycle operates at an overall thermal efficiency in excess of 45%, and the overall economics of hydrogen production by this plant have been evaluated predicated on a consistent set of economic ground rules. The conceptual design and evaluation efforts have indicated that development of this type of nuclear-driven water-decomposition plant will permit large-scale economic generation of hydrogen in the 1990s.

Parker, G. H.; Brecher, L. E.; Farbman, G. H.

1976-01-01

2

[Effects of aquatic plants during their decay and decomposition on water quality].  

PubMed

Taking 6 aquatic plant species as test objects, a 64-day decomposition experiment was conducted to study the temporal variation patterns of nutrient concentration in water body during the process of the aquatic plant decomposition. There existed greater differences in the decomposition rates between the 6 species. Floating-leaved plants had the highest decomposition rate, followed by submerged plants, and emerged plants. The effects of the aquatic plant species during their decomposition on water quality differed, which was related to the plant biomass density. During the decomposition of Phragmites australis, water body had the lowest concentrations of chemical oxygen demand, total nitrogen, and total phosphorus. In the late decomposition period of Zizania latifolia, the concentrations of water body chemical oxygen demand and total nitrogen increased, resulting in the deterioration of water quality. In the decomposition processes of Nymphoides peltatum and Nelumbo nucifera, the concentrations of water body chemical oxygen demand and total nitrogen were higher than those during the decomposition of other test plants. In contrast, during the decomposition of Potamogeton crispus and Myriophyllum verticillatum, water body had the highest concentrations of ammonium, nitrate, and total phosphorus. For a given plant species, the main water quality indices had the similar variation trends under different biomass densities. It was suggested that the existence of moderate plant residues could effectively promote the nitrogen and phosphorus cycles in water body, reduce its nitrate concentration to some extent, and decrease the water body nitrogen load. PMID:23717994

Tang, Jin-Yan; Cao, Pei-Pei; Xu, Chi; Liu, Mao-Song

2013-01-01

3

The Conceptual Design of an Integrated Nuclearhydrogen Production Plant Using the Sulfur Cycle Water Decomposition System  

NASA Technical Reports Server (NTRS)

A hydrogen production plant was designed based on a hybrid electrolytic-thermochemical process for decomposing water. The sulfur cycle water decomposition system is driven by a very high temperature nuclear reactor that provides 1,283 K helium working gas. The plant is sized to approximately ten million standard cubic meters per day of electrolytically pure hydrogen and has an overall thermal efficiently of 45.2 percent. The economics of the plant were evaluated using ground rules which include a 1974 cost basis without escalation, financing structure and other economic factors. Taking into account capital, operation, maintenance and nuclear fuel cycle costs, the cost of product hydrogen was calculated at $5.96/std cu m for utility financing. These values are significantly lower than hydrogen costs from conventional water electrolysis plants and competitive with hydrogen from coal gasification plants.

Farbman, G. H.

1976-01-01

4

Water Limitation and Plant Inter-specific Competition Reduce Rhizosphere-Induced C Decomposition and Plant N Uptake  

Technology Transfer Automated Retrieval System (TEKTRAN)

1. Plants can affect soil organic matter decomposition and mineralization through litter inputs, but also more directly through root-microbial interactions (rhizosphere effects). Depending on resource availability and plant species identity, these rhizosphere effects can be positive or negative. To...

5

Phlogopite Decomposition, Water, and Venus  

NASA Technical Reports Server (NTRS)

Venus is a hot and dry planet with a surface temperature of 660 to 740 K and 30 parts per million by volume (ppmv) water vapor in its lower atmosphere. In contrast Earth has an average surface temperature of 288 K and 1-4% water vapor in its troposphere. The hot and dry conditions on Venus led many to speculate that hydrous minerals on the surface of Venus would not be there today even though they might have formed in a potentially wetter past. Thermodynamic calculations predict that many hydrous minerals are unstable under current Venusian conditions. Thermodynamics predicts whether a particular mineral is stable or not, but we need experimental data on the decomposition rate of hydrous minerals to determine if they survive on Venus today. Previously, we determined the decomposition rate of the amphibole tremolite, and found that it could exist for billions of years at current surface conditions. Here, we present our initial results on the decomposition of phlogopite mica, another common hydrous mineral on Earth.

Johnson, N. M.; Fegley, B., Jr.

2005-01-01

6

Decomposition kinetics of maltose in subcritical water.  

PubMed

The decomposition process of maltose in subcritical water was studied using a tubular reactor in the temperature range of 180 to 260 degrees C and at 10 MPa. The formation of glucose and 5-hydroxymethyl-2-furaldehyde during the maltose decomposition was also observed. The decomposition rate of maltose was faster at higher temperatures. The rate was approximated by first-order kinetics during the early stage of the decomposition, but was accelerated and deviated from these kinetics at the later stage. The effluent pH decreased as the residence time in the reactor increased and the decrease of pH affected the maltose decomposition rate and glucose formation. Low pH of a feed solution accelerated maltose decomposition. A good correlation was obtained between the pH of the effluent and the rate constant of the first-order kinetics. PMID:14745169

Haghighat Khajavi, Shabnam; Kimura, Yukitaka; Oomori, Toshinobu; Matsuno, Ryuichi; Adachi, Shuji

2004-01-01

7

“Afterlife” effects of mycorrhization on the decomposition of plant residues  

Microsoft Academic Search

The symbiosis with arbuscular mycorrhizal fungi is known to affect growth and tissue quality of plants. Therefore, mycorrhization may also have “afterlife” effects on decomposition dynamics. We tested this hypothesis with plant material of mycorrhized and non-mycorrhized plants of seven grassland species. We found that mycorrhization increased the decomposition rate and interpret this result as a consequence of the enhanced nutritive

Martin Schädler; Roland Brandl; Anne Kempel

2010-01-01

8

Plant Identity Influences Decomposition through More Than One Mechanism  

PubMed Central

Plant litter decomposition is a critical ecosystem process representing a major pathway for carbon flux, but little is known about how it is affected by changes in plant composition and diversity. Single plant functional groups (graminoids, legumes, non-leguminous forbs) were removed from a grassland in northern Canada to examine the impacts of functional group identity on decomposition. Removals were conducted within two different environmental contexts (fertilization and fungicide application) to examine the context-dependency of these identity effects. We examined two different mechanisms by which the loss of plant functional groups may impact decomposition: effects of the living plant community on the decomposition microenvironment, and changes in the species composition of the decomposing litter, as well as the interaction between these mechanisms. We show that the identity of the plant functional group removed affects decomposition through both mechanisms. Removal of both graminoids and forbs slowed decomposition through changes in the decomposition microenvironment. We found non-additive effects of litter mixing, with both the direction and identity of the functional group responsible depending on year; in 2004 graminoids positively influenced decomposition whereas in 2006 forbs negatively influenced decomposition rate. Although these two mechanisms act independently, their effects may be additive if both mechanisms are considered simultaneously. It is essential to understand the variety of mechanisms through which even a single ecosystem property is affected if we are to predict the future consequences of biodiversity loss. PMID:21858210

McLaren, Jennie R.; Turkington, Roy

2011-01-01

9

Effect of water level drawdown on decomposition in boreal peatlands  

NASA Astrophysics Data System (ADS)

Plant litter production and decomposition are key processes in element cycling in most ecosystems. In peatlands, there has been a long-term imbalance between litter production and decay caused by high water levels (WL) and consequent anoxia. This has resulted in peatlands being a significant sink of carbon (C) from the atmosphere. However, peatlands are experiencing both "natural" (global climate change) and anthropogenic (ditching) changes that threaten their ability to retain this ecosystem identity and function. Many of these alterations can be traced back to WL drawdown, which can cause increased aeration, higher acidity, falling temperatures, and a greater probability of drought. Such changes are also associated with an increasing decomposition rate, and therefore a greater amount of C released back to the atmosphere. Yet studies about how the overall C balance of peatlands will be affected have come up with conflicting conclusions, demonstrating that the C store could increase, decrease, or remain static. A factor that has been largely overlooked is the change in litter type composition following persistent WL drawdown. It is the aim of our study, then, to help to resolve this issue. We studied the effects of short-term (ca. 4 years) and long-term (ca. 40 years) persistent WL drawdown on the decomposition of numerous types of above-ground and below-ground plant litters at three boreal peatland sites: bog, oligotrophic fen and mesotrophic fen. We thus believe that enough permutations have been created to obtain a good assessment of how each factor, site nutrient level, WL regime, and litter type composition, influences decomposition. We used the litter bag method to measure the decomposition rates: placed measured amounts of plant litter, or cellulose strips as a control, into closed mesh bags, and installed the bags in the natural environment for decomposition for each litter type for varying amounts of time. Following litter bag recovery, the litter was cleaned of excess debris and analyzed for changes in mass, enzyme activity, mesofauna presence, and microbial community composition, among other things. The experiment has a run-time of ten years, the results from the first two years are presented in the poster.

Straková, Petra; Penttilä, Timo; Laiho, Raija

2010-05-01

10

Hydrogen production by the decomposition of water  

DOEpatents

How to produce hydrogen from water was a problem addressed by this invention. The solution employs a combined electrolytical-thermochemical sulfuric acid process. Additionally, high purity sulfuric acid can be produced in the process. Water and SO.sub.2 react in electrolyzer (12) so that hydrogen is produced at the cathode and sulfuric acid is produced at the anode. Then the sulfuric acid is reacted with a particular compound M.sub.r X.sub.s so as to form at least one water insoluble sulfate and at least one water insoluble oxide of molybdenum, tungsten, or boron. Water is removed by filtration; and the sulfate is decomposed in the presence of the oxide in sulfate decomposition zone (21), thus forming SO.sub.3 and reforming M.sub.r X.sub.s. The M.sub.r X.sub.s is recycled to sulfate formation zone (16). If desired, the SO.sub.3 can be decomposed to SO.sub.2 and O.sub.2 ; and the SO.sub.2 can be recycled to electrolyzer (12) to provide a cycle for producing hydrogen.

Hollabaugh, Charles M. (Los Alamos, NM); Bowman, Melvin G. (Los Alamos, NM)

1981-01-01

11

Tremolite Decomposition and Water on Venus  

NASA Technical Reports Server (NTRS)

We present experimental data showing that the decomposition rate of tremolite, a hydrous mineral, is sufficiently slow that it can survive thermal decomposition on Venus over geologic timescales at current and higher surface temperatures.

Johnson, N. M.; Fegley, B., Jr.

2000-01-01

12

Water Desalination Plant  

NSDL National Science Digital Library

Students use a thermal process approach to design, build and test a small-scale desalination plant that is capable of significantly removing the salt content from a saltwater solution. Students use a saltwater circuit to test the efficiency of their model desalination plant and learn how the water cycle is the basis for the thermal processes that drive their desalination plant.

Integrated Teaching and Learning Program,

13

Does accelerated soil organic matter decomposition in the presence of plants increase plant N availability?  

Microsoft Academic Search

Plant roots can increase microbial activity and soil organic matter (SOM) decomposition via rhizosphere priming effects. It is virtually unknown how differences in the priming effect among plant species and soil type affect N mineralization and plant uptake. In a greenhouse experiment, we tested whether priming effects caused by Fremont cottonwood (Populus fremontii) and Ponderosa pine (Pinus ponderosa) grown in

Feike A. Dijkstra; Nicholas E. Bader; Dale W. Johnson; Weixin Cheng

2009-01-01

14

Water reclamation plant  

NSDL National Science Digital Library

In this video clip, students see how wastewater is treated at a water reclamation plant. One of the plant's operators gives Bob the Vid Tec (a children's programming host) a tour of the plant, describing along the way what happens at each step in the water treatment process. For example, the operator explains that microorganisms are used to consume human waste in the biological nutrient removal step. Bob also talks with another plant operator about why kids should learn about wastewater treatment. Both of the operators discuss the problems that grease and cooking oil create for water treatment. Students are reminded that usable water is a limited resource that should be safeguarded. Copyright 2005 Eisenhower National Clearinghouse

Johns Hopkins University. Center for Technology in Education (CTE)

2004-01-01

15

Dynamics of alpine plant litter decomposition in a changing climate  

Microsoft Academic Search

Climatic changes resulting from anthropogenic activities over the passed century are repeatedly reported to alter the functioning\\u000a of pristine ecosystems worldwide, and especially those in cold biomes. Available literature on the process of plant leaf litter\\u000a decomposition in the temperate Alpine zone is reviewed here, with emphasis on both direct and indirect effects of climate\\u000a change phenomena on rates of

Konstantin S. Gavazov

2010-01-01

16

Plant decomposition and soil respiration in terrestrial ecosystems  

Microsoft Academic Search

Summary  This review deals with methodological approaches, measured rates, and environmental control of two major interdependent processes\\u000a regulating the structure and function of terrestrial ecosystems, viz., plant decomposition and soil respiration.\\u000a \\u000a Both these processes have been evaluated through indirect assessments as well as through direct measurements under the field\\u000a conditions. The techniques used suffer in general from difficulties in creating conditions

J. S. Singh; S. R. Gupta

1977-01-01

17

Decomposition of Plant Debris by the Nematophagous Fungus ARF  

PubMed Central

In the study of the biological control of plant-parasitic nematodes, knowledge of the saprophytic ability of a nematophagous fungus is necessary to understand its establishment and survival in the soil. The objectives of this study were (i) to determine if the nematophagous fungus ARF (Arkansas Fungus) shows differential use of plant residues; and (ii) to determine if ARF still existed in the soil of a field in which ARF was found originally and in which the population level of Heterodera glycines had remained very low, despite 15 years of continuous, susceptible soybean. Laboratory studies of the decomposition of wheat straw or soybean root by ARF were conducted in two separate experiments, using a CO? collection apparatus, where CO?-free air was passed through sterilized cotton to remove the microorganisms in the air and then was passed over the samples, and evolved CO? was trapped by KOH. Milligrams of C as CO? was used to calculate the percentage decomposition of the plant debris by ARF. Data indicated ARF decomposed 11.7% of total organic carbon of the wheat straw and 20.1% of the soybean roots in 6 weeks. In the field soil study, 21 soil samples were taken randomly from the field. Only 3 months after the infestation of the soil with H. glycines, the percentage of parasitized eggs of H. glycines reached 64 ± 19%, and ARF was isolated from most parasitized eggs of H. glycines. Research results indicated ARF could use plant residues to survive. PMID:19262814

Wang, Kening; Riggs, R. D.; Crippen, Devany

2004-01-01

18

Metal-induced decomposition of perchlorate in pressurized hot water.  

PubMed

Decomposition of perchlorate (ClO(4)(-)) in pressurized hot water (PHW) was investigated. Although ClO(4)(-) demonstrated little reactivity in pure PHW up to 300°C, addition of zerovalent metals to the reaction system enhanced the decomposition of ClO(4)(-) to Cl(-) with an increasing order of activity of (no metal)?Al < Cu < Zn < Ni < Fe: the addition of iron powder led to the most efficient decomposition of ClO(4)(-). When the iron powder was added to an aqueous ClO(4)(-) solution (104 ?M) and the mixture was heated at 150°C, ClO(4)(-) concentration fell below 0.58 ?M (58 ?g L(-1), detection limit of ion chromatography) in 1 h, and Cl(-) was formed with the yield of 85% after 6 h. The decomposition was accompanied by transformation of the zerovalent iron to Fe(3)O(4). This method was successfully used in the decomposition of ClO(4)(-) in a water sample contaminated with this compound, following fireworks display at Albany, New York, USA. PMID:22840541

Hori, Hisao; Sakamoto, Takehiko; Tanabe, Takashi; Kasuya, Miu; Chino, Asako; Wu, Qian; Kannan, Kurunthachalam

2012-10-01

19

Decomposition of polycarbonate in subcritical and supercritical water  

Microsoft Academic Search

Polycarbonate was decomposed into phenol, bisphenol A, p-isopropenylphenol, and p-isopropylphenol by the reaction at 230°C to 430°C in water. The decomposition reactions were accelerated by the addition of Na2CO3, and the yields of identified products reached 67% even in the reaction at 300°C for 24h.

Hideyuki Tagaya; Kazuya Katoh; Jun-ichi Kadokawa; Koji Chiba

1999-01-01

20

Radiation induced decomposition of hydrocarbons in water resources  

NASA Astrophysics Data System (ADS)

Radiation induced decomposition of various organic compounds, such as phenols, chlorinated hydrocarbons, dyestuffs etc. in water represents a new and very efficient possibility for elimination of the steadily increasing pollution. Experimental results considering the removal of phenol, phenolic compounds, mixture of aliphatic and aromatic hydrocarbons, as well as chlorinated compounds etc. in waste water under irradiation were reported. Basic considerations of probable reaction mechanisms were also presented.

Getoff, N.; Lutz, W.

21

Kinetics of the pyrolytic and hydrothermal decomposition of water hyacinth.  

PubMed

The kinetics of water hyacinth decomposition using pyrolysis and hydrothermal treatment was compared. With pyrolysis, initial vaporization occurred at 453 K as determined by thermogravimetric analysis, while initial solubilisation occurred at 433 K with subcritical hydrothermal treatment. The "kinetic triplet" was determined for the ranges of 423-483 K (range I) and 473-553 K (range II) using the Coats-Redfern method for both treatments. The calculated activation energies for ranges I and II were 110 and 116 kJ/mol for conventional pyrolysis and 145 and 90 kJ/mol for hydrothermal treatment. The similar activation energies for the two temperature ranges observed for pyrolysis implied that only hemicellulose decomposition occurred. For hydrothermal treatment, both hemicellulose and cellulose decomposition occurred in temperature range II, in which a notable lower activation energy was observed. This implied hydrothermal treatment was more suitable for conversion lignocellulosic biomass under these conditions. PMID:21558054

Luo, Guang'en; Strong, P James; Wang, Hailong; Ni, Wuzhong; Shi, Weiyong

2011-07-01

22

Plant traits are the predominant control on litter decomposition rates within biomes worldwide  

Microsoft Academic Search

Worldwide decomposition rates depend both on climate and the legacy of plant functional traits as litter quality. To quantify the degree to which functional differentiation among species affects their litter decomposition rates, we brought together leaf trait and litter mass loss data for 818 species from 66 decomposition experiments on six continents. We show that: (i) the magnitude of species-driven

William K. Cornwell; Johannes H. C. Cornelissen; K. Amatangalo; Ellen Dorrepaal; Valerie T. Eviner; Oscar Godoy; S. E. Hobbir; Bart Hoorens; Hiroko Kurokawa; N. Perez-Harguindeguy; Helen M. Quested; Louis S. Santiago; David A. Wardle; Ian J. Wright; Rien Aerts; Steven D. Allison; Bodegom van P. M; Victor Brovkin; Alex Chatain; Terry V. Callaghan; S. Diaz; Eric Garnier; Diego E. Gurvich; Elena Kazakou; Julia A. Klein; Jenny Read; Peter B. Reich; Nadejda A. Soudzilovskaia; M. Victoria Vaieretti; Mark Westoby

2008-01-01

23

SOIL WATER SENSING FOR PLANT WATER UPTAKE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Of the many ways to deduce plant water uptake, the soil water balance is the most frequently used, with plant water uptake determined as the residual of other terms in the equation. Extensive work with weighing lysimeters and soil water sensing methods allows us to contrast the effectiveness of and ...

24

Plant Hormones and Water Stress  

Microsoft Academic Search

In recent years, the involvement of plant hormones has become a subject of interest in plant water relations. The interest was initially stimulated by research into leaf ageing and plant senescence and the role of cytokinins in these processes. Plant water stress and some other stresses enhance senescence. They also bring about reduction in the levels of endogenous cytokinins. Exogenous

Y. Vaadia

1976-01-01

25

Emissions of volatile organic compounds during the decomposition of plant litter  

E-print Network

Emissions of volatile organic compounds during the decomposition of plant litter Christopher M plant litter decomposition, and such VOCs can have wideranging impacts on atmospheric chemistry of the relative importance of biotic versus abiotic sources of these VOCs and whether distinct types of litter

Fierer, Noah

26

Hydrogen production by water decomposition using a combined electrolytic-thermochemical cycle  

NASA Technical Reports Server (NTRS)

A proposed dual-purpose power plant generating nuclear power to provide energy for driving a water decomposition system is described. The entire system, dubbed Sulfur Cycle Water Decomposition System, works on sulfur compounds (sulfuric acid feedstock, sulfur oxides) in a hybrid electrolytic-thermochemical cycle; performance superior to either all-electrolysis systems or presently known all-thermochemical systems is claimed. The 3345 MW(th) graphite-moderated helium-cooled reactor (VHTR - Very High Temperature Reactor) generates both high-temperature heat and electric power for the process; the gas stream at core exit is heated to 1850 F. Reactor operation is described and reactor innards are illustrated. A cost assessment for on-stream performance in the 1990's is optimistic.

Farbman, G. H.; Brecher, L. E.

1976-01-01

27

Glucose and fructose decomposition in subcritical and supercritical water: Detailed reaction pathway, mechanisms, and kinetics  

Microsoft Academic Search

The authors are developing a new catalyst-free process of cellulose decomposition in supercritical water. In their initial study on the cellulose decomposition in supercritical water, the main products of cellulose decomposition were found to be oligomers of glucose (cellobiose, cellotriose, etc.) and glucose at short residence times (400 C, 25 MPa, 0.05 s). The kinetics of glucose at these conditions

Bernard M. Kabyemela; Tadafumi Adschiri; Roberto M. Malaluan; Kunio Arai

1999-01-01

28

Stoichiometry of Microbial Decomposition Priming in Plant Litter and Soil  

NASA Astrophysics Data System (ADS)

Microbial priming is accelerated conversion of plant residues and soil organic carbon to CO2. It is caused by small additions of labile carbon and nitrogen compounds, but microbial stoichiometry suggests that this description is incomplete. The temperature dependence of soil organic carbon cycling models may be related to diffusion of labile resources to microbial cells. Incomplete treatment of stoichiometrically significant elements in these models may also limit their ability to predict carbon fluxes if plant species, diseases or defoliators are affected by climate changes. We explore this by incubating decomposable substrates (leaves, wood, humus and mineral soil) with resources added as dissolved inorganic nitrogen (ammonium and nitrate separately), phosphorus and sugar, added in different amounts and proportions. We measure CO2 production by infrared absorption. Contribution of sugar to CO2 production is assessed by mass spectrometry. High concentrations for each resource are 16X the low, and middle concentrations are 4X the low. The ratios are centered on 200:10:1. We explore C:N:P resource ratios and additions over wide ranges; subsequently to examine narrower ranges of interest. For C:N:P incubations, C and N effects are always significant on CO2 production, with P in only half of the treatments. Literature suggests that leaf-litter decomposition is stimulated by N (occasionally P) additions, but results for soils have been mixed. We find N to be inhibitory only when added in "stoichiometic excess" to added C. Stimulation of microbial respiration is generally strongest with C:N:P additions in "Redfield-like" ratios, but the response is far below linear. Humus has a stronger response to C than do leaves and wood. This is consistent with a chronic energy limitation for soil microbes, even where their environments contain large amounts of total C. For all substrates, the addition of N as nitrate leads to significantly more CO2 than the same amount of ammonium-N. This result was unexpected because nitrate must be reduced (at metabolic cost) before it can be utilized in cells. Possible explanations include relatively less mobility of ammonium in the environment, and enzyme syntheses being more inhibited by ammonium. At least, it suggests that studies treating ammonium and nitrate as equivalent N sources miss important aspects of microbial metabolism. In incubations with only P as an added resource, CO2 production was stimulated in all substrates except leaf, but only with much larger P additions compared to the C:N:P incubations. Previous studies have shown that leaf decomposition can be stimulated by added P, but among these 4 substrates, we suggest that leaves have the highest amounts of available P relative to C. Further studies will be presented, including microbial community assessment by PCR-DGGE. Thus far, we see that stimulation of microbial respiration is greatest when C is added above cellular stoichiometric ratios for N and P, emphasizing energy costs associated with microbial growth and exoenzyme synthesis. In addition, the most effective C:N:P resource ratios for decomposition vary widely among substrates. These results can contribute to the development of decomposition and soil organic carbon models with greater biological realism. .

Schaefer, D.; Qiao, N.

2011-12-01

29

PCB decomposition and formation in thermal treatment plant equipment.  

PubMed

In this study we investigated both the decomposition and unintentional formation of polychlorinated biphenyl congeners during combustion experiments of refuse-derived fuel (RDF) and automobile shredder residue (ASR) at several stages in thermal treatment plant equipment composed of a primary combustion chamber, a secondary combustion chamber, and other equipments for flue gas treatment. In both experiments, the unintentional formation of PCB occurred in the primary combustion chamber at the same time as the decomposition of PCB in input samples. By combusting RDF, non-ortho-PCB predominantly formed, whereas ortho-PCB and symmetric chlorinated biphenyls (e.g., #52/69, #87/108, and #151) tended to be decomposed. ASR formed the higher chlorinated biphenyls more than RDF. These by-products from ASR had no structural relation with ortho-chlorine. Lower chlorinated biphenyls appeared as predominant homologues at the final exit site, while all congeners from lower to higher chlorinated PCB were unintentionally formed as by-products in the primary combustion chamber. This result showed that the flue gas treatment equipments effectively removed higher chlorinated PCB. Input marker congeners of RDF were #11, #39, and #68, while those for ASR were #11, #101, #110/120, and #118. Otherwise, combustion marker congeners of RDF were #13/12, #35, #77, and #126, while those for ASR were #170, #194, #206, and #209. While the concentration of PCB increased significantly in the primary combustion chamber, the value of toxicity equivalency quantity for dioxin-like PCB decreased in the secondary combustion chamber and the flue gas treatment equipments. PMID:17134732

Ishikawa, Yukari; Noma, Yukio; Yamamoto, Takashi; Mori, Yoshihito; Sakai, Shin-ichi

2007-04-01

30

Researching power plant water recovery  

SciTech Connect

A range of projects supported by NETl under the Innovations for Existing Plant Program are investigating modifications to power plant cooling systems for reducing water loss, and recovering water from the flue gas and the cooling tower. This paper discusses two technologies showing particular promise condense water that is typically lost to evaporation, SPX technologies' Air2Air{sup trademark} condenses water from a cooling tower, while Lehigh University's process condenses water and acid in flue gas. 3 figs.

NONE

2008-04-01

31

North City Water Reclamation Plant  

E-print Network

North City Water Reclamation Plant Maja Caroee Diana Lee Niko Salvador #12;What is Water Reclamation? Water Reclamation is the process of treating wastewater to be suitable for reuse Not Suitable Planning for Water Reclamation ProgramPlanning for Water Reclamation Program Late 1980's Construction began

Prevedouros, Panos D.

32

Decomposition of Glycerine by Water Plasmas at Atmospheric Pressure  

NASA Astrophysics Data System (ADS)

High concentration of aqueous glycerine was decomposed using a direct current (DC) plasma torch at atmospheric pressure. The torch can generate the plasma with water as the plasma-supporting gas in the absence of any additional gas supply system and cooling devices. The results indicated that 5 mol% glycerine was completely decomposed by water plasmas at arc powers of 0.55~1.05 kW. The major products in the effluent gas were H2 (68.9%~71.1%), CO2 (18.9%~23.0%), and CO (0.2%~0.6%). However, trace levels of formic acid (HCOOH) and formaldehyde (HCHO) were observed in the liquid effluent. The results indicated that the water plasma waste treatment process is capable of being an alternative green technology for organic waste decomposition.

Takayuki, Watanabe; Narengerile

2013-04-01

33

Elevated CO2 and plant species diversity interact to slow root decomposition  

SciTech Connect

Changes in plant species diversity can result in synergistic increases in decomposition rates, while elevated atmospheric CO2 can slow the decomposition rates; yet it remains unclear how diversity and changes in atmospheric CO2 may interact to alter root decomposition. To investigate how elevated CO2 interacts with changes in root-litter diversity to alter decomposition rates, we conducted a 120-day laboratory incubation. Roots from three species (Trifolium repens, Lespedeza cuneata, and Festuca pratense) grown under ambient or elevated CO2 were incubated individually or in combination in soils that were exposed to ambient or elevated CO2 for five years. Our experiment resulted in two main findings: (1) Roots from T. repens and L. cuneata, both nitrogen (N) fixers, grown under elevated CO2 treatments had significantly slower decomposition rates than similar roots grown under ambient CO2 treatments; but the decomposition rate of F. pratense roots (a non-N-fixing species) was similar regardless of CO2 treatment. (2) Roots of the three species grown under ambient CO2 and decomposed in combination with each other had faster decomposition rates than when they were decomposed as single species. However, roots of the three species grown under elevated CO2 had similar decomposition rates when they were incubated alone or in combination with other species. These data suggest that if elevated CO2 reduces the root decomposition rate of even a few species in the community, it may slow root decomposition of the entire plant community.

De Graaff, Marie-Anne [ORNL; Schadt, Christopher Warren [ORNL; Rula, Kelly L [ORNL; Six, Johan W U A [University of California, Davis; Schweitzer, Jennifer A [ORNL; Classen, Aimee T [University of Tennessee, Knoxville (UTK)

2011-01-01

34

Decomposition of tree leaf litter on pavement: implications for urban water quality  

E-print Network

Decomposition of tree leaf litter on pavement: implications for urban water quality Sarah E. Hobbie decomposition and nutrient release from leaf litter that falls on impervious surfaces is important environment of the street gutter. We compared decomposition of leaf litter of five street tree species

Weiblen, George D

35

Decomposition  

USGS Publications Warehouse

A cornerstone of ecosystem ecology, decomposition was recognized as a fundamental process driving the exchange of energy in ecosystems by early ecologists such as Lindeman 1942 and Odum 1960). In the history of ecology, studies of decomposition were incorporated into the International Biological Program in the 1960s to compare the nature of organic matter breakdown in various ecosystem types. Such studies still have an important role in ecological studies of today. More recent refinements have brought debates on the relative role microbes, invertebrates and environment in the breakdown and release of carbon into the atmosphere, as well as how nutrient cycling, production and other ecosystem processes regulated by decomposition may shift with climate change. Therefore, this bibliography examines the primary literature related to organic matter breakdown, but it also explores topics in which decomposition plays a key supporting role including vegetation composition, latitudinal gradients, altered ecosystems, anthropogenic impacts, carbon storage, and climate change models. Knowledge of these topics is relevant to both the study of ecosystem ecology as well projections of future conditions for human societies.

Middleton, Beth A.

2014-01-01

36

Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications  

Microsoft Academic Search

Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood (Avicennia germinans), cypress needles and wood (Taxodium distichum) and smooth cordgrass (Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39,

Stephen Opsahl; Ronald Benner

1995-01-01

37

Additive Effect of Water on the Decomposition of VOCs in Nonthermal Plasma  

Microsoft Academic Search

In the removal of volatile organic compounds (VOCs) with nonthermal plasma (NTP), the additive effect of water on VOC decomposition is an important issue to be solved since water is contained in VOC exhausts. Although there have been disputed discussions on the additive effect of water on the decomposition of VOCs in NTP, a unified mechanism has not been established

Masami Sugasawa; Tomoyuki Terasawa; Shigeru Futamura

2010-01-01

38

What drives plant litter decomposition globally? Ecological Monographs?  

E-print Network

and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996 #12;Abstract - 268 Global leaf-litter in species composition may have the potential to drive the ecosystem function of leaf litter decomposition. Keywords: leaf litter decomposition, aquatic-terrestrial comparison, meta-analysis Introduction #12;Global

Tennessee, University of

39

Experimental study of hydrogen production by direct decomposition of water  

NASA Astrophysics Data System (ADS)

The hydrogen production by direct decomposition of water in a solar furnace is studied. The set-up is a horizontal axis system consisting of two 1.0 kW parabolic concentrators, both powered by a single heliostat. A temperature of 3000 K is possible. The water is fed to the reactor installed at the focal space of the concentrator, and the steam is decomposed at about 2500 K. The reactor consisted of a cylindrical cavity type refractory receiver covered with a silica cupola. The steam was introduced at a known rate into the cavity and the product gases were quenched. After the condensation of steam, hydrogen and oxygen were collected in a reservoir. Results indicate that with an optimized system, it is possible to produce hydrogen at about 70 percent rate of the theoretical value at the temperature level studied.

Bilgen, E.; Galindo, J.; Baykara, S. Z.

40

Water Filtration Using Plant Xylem  

PubMed Central

Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

2014-01-01

41

Water Treatment Plant  

NSDL National Science Digital Library

In most parts of the United States, getting clean, safe water is as easy as turning on a faucet. Generally, this water comes from either groundwater or nearby streams and reservoirs. What most of us never see or have to worry about are the steps required to make this water drinkable. This video segment, adapted from a ZOOM television broadcast, shows how a water treatment facility in Cambridge, Massachusetts purifies its city's water. The segment is two minutes twenty seconds in length.

42

[Characteristics of the biochemical composition of plant litter at different stages of decomposition (according to thermal analysis data)].  

PubMed

The composition of samples of needles, leaves, sheaved cottongrass (Eriophorum vaginatum) tissues, and the L horizon of the forest floor of different degree of decomposition, isolated from the plant litter in southern taiga ecosystems, was studied by thermal analysis. It was established that plant litter decomposition is accompanied by structural changes in celluloses and that the decomposition rates of hemicellulose and structured cellulose vary at different stages of decomposition. The structural specificity and incongruent thermal decomposition of grass lignocellulose were observed in all samples of plant material. The rates at which the content of components of the plant litter decreased depended on the type and stage of decomposition of plant material. The decomposition rate of biochemical components tended to increase in better drained soils. PMID:18491564

Kosheleva, Iu P; Trofimov, S Ia

2008-01-01

43

Power Plant Water Intake Assessment.  

ERIC Educational Resources Information Center

In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

Zeitoun, Ibrahim H.; And Others

1980-01-01

44

Labile soil carbon inputs mediate the soil microbial community composition and plant residue decomposition rates  

SciTech Connect

Root carbon (C) inputs may regulate decomposition rates in soil, and in this study we ask: how do labile C inputs regulate decomposition of plant residues, and soil microbial communities? In a 14 d laboratory incubation, we added C compounds often found in root exudates in seven different concentrations (0, 0.7, 1.4, 3.6, 7.2, 14.4 and 21.7 mg C g{sup -1} soil) to soils amended with and without {sup 13}C-labeled plant residue. We measured CO{sub 2} respiration and shifts in relative fungal and bacterial rRNA gene copy numbers using quantitative polymerase chain reaction (qPCR). Increased labile C input enhanced total C respiration, but only addition of C at low concentrations (0.7 mg C g{sup -1}) stimulated plant residue decomposition (+2%). Intermediate concentrations (1.4, 3.6 mg C g{sup -1}) had no impact on plant residue decomposition, while greater concentrations of C (> 7.2 mg C g{sup -1}) reduced decomposition (-50%). Concurrently, high exudate concentrations (> 3.6 mg C g{sup -1}) increased fungal and bacterial gene copy numbers, whereas low exudate concentrations (< 3.6 mg C g{sup -1}) increased metabolic activity rather than gene copy numbers. These results underscore that labile soil C inputs can regulate decomposition of more recalcitrant soil C by controlling the activity and relative abundance of fungi and bacteria.

De Graaff, Marie-Anne [ORNL; Classen, Aimee T [University of Tennessee, Knoxville (UTK); Castro Gonzalez, Hector F [ORNL; Schadt, Christopher Warren [ORNL

2010-01-01

45

Transpiration - Water Movement through Plants  

NSDL National Science Digital Library

This lesson and its animation follows the journey of water through a plant from its uptake by roots to its evaporation from the leaf surface. How this journey is altered by plant characteristics such as stomata and cuticles as well as by changes in the environment will be described.

46

Plant transpiration distillation of water  

SciTech Connect

A project using solar energy and the transpiration of plants for the distillation of water is described. Along with determining which of three plants thrived best growing in a still, the experiment also revealed that the still functioned nearly as well in inclement weather as in fair weather.

Virostko, M.K.; Spielberg, J.I.

1986-01-01

47

Waste Water Plant Operators Manual.  

ERIC Educational Resources Information Center

This manual for sewage treatment plant operators was prepared by a committee of operators, educators, and engineers for use as a reference text and handbook and to serve as a training manual for short course and certification programs. Sewage treatment plant operators have a responsibility in water quality control; they are the principal actors in…

Washington State Coordinating Council for Occupational Education, Olympia.

48

Interactions between decomposition of plant residues and nitrogen cycling in soil  

Microsoft Academic Search

The processes of N mineralization and immobilization which can occur in agricultural soils during decomposition of plant residues are briefly reviewed in this paper. Results from different incubation studies have indicated that the amounts of N immobilized can be very important and that the intensity and kinetics of N immobilization and subsequent remineralization depend on the nature of plant residues

B. Mary; S. Recous; D. Darwis; D. Robin

1996-01-01

49

Transpiration: Water Movement Through Plants  

NSDL National Science Digital Library

Learn the basics of transpiration -- the transportation of water through plants from soil to leaves to atmosphere -- with this playful animation created by weed physiologist Tracy Sterling and animator Matt Byrnes. Interactive features allow you to explore the process including how changing environmental conditions can impact how fast water moves.

Tracy Sterling (New Mexico State University; )

2005-09-23

50

[Decomposition of different plant litters in Loess Plateau of Northwest China].  

PubMed

Taking the litters of species Hippophae rhamnoides, Medicago sativa, Populus simonii, Robinia pseudoacaci, Salix psammophila, and Stipa bungeana in the Loess Plateau of Northeast China as test objects, and by using mesh bags, this paper studied the dynamic changes of the litters mass, carbon, and nitrogen during decomposition after buried in the field in semiarid region. The litters buried were from one, two, or three of the plant species, and mixed thoroughly with equal proportion of masses. During decomposition, the mass loss rate, total carbon and nitrogen release rates, and total soluble carbon and nitrogen contents of different litters were higher at the early than at the later decomposition stage. After 412 d decomposition, the average mass loss rate of the litters was in the order of mixed litters of three plant species > mixed litters of two plant species > one plant species litter. By the end of this experiment, the average release rates of the litter total carbon and nitrogen ranked as one plant species litter > mixed litters of two plant species > mixed litters of three plant species, the litter soluble organic carbon content was mixed litters of two plant species > mixed litters of three plant species > one plant species litter, while the litter soluble total nitrogen content was mixed litters of three plant species > mixed litters of two plant species > one plant species litter. Correlation analysis showed that the litter mass loss rate had definite correlation with the litter soluble organic matter, especially soluble organic carbon. From the viewpoint of mass loss rate, the mixture of the litters of P. simonii, H. rhamnoide, and M. sativa was the optimum. It was suggested that in the process of returning farmland into forestland and grassland in the gully and valley region of Loess Plateau, it would be required to rationally increase plant species diversity to improve soil fertility. PMID:23479871

Li, Yun; Zhou, Jian-Bin; Dong, Yan-Jie; Xia, Zhi-Min; Chen, Zhu-Juin

2012-12-01

51

Interactions among fungal community structure, litter decomposition and depth of water table in a cutover peatland.  

PubMed

Peatlands are important reservoirs of carbon (C) but our understanding of C cycling on cutover peatlands is limited. We investigated the decomposition over 18 months of five types of plant litter (Calluna vulgaris, Eriophorum angustifolium, Eriophorum vaginatum, Picea sitchensis and Sphagnum auriculatum) at a cutover peatland in Scotland, at three water tables. We measured changes in C, nitrogen (N) and phosphorus (P) in the litter and used denaturing gradient gel electrophoresis to investigate changes in fungal community composition. The C content of S. auriculatum litter did not change throughout the incubation period whereas vascular plant litters lost 30-40% of their initial C. There were no differences in C losses between low and medium water tables, but losses were always significantly less at the high water table. Most litters accumulated N and E. angustifolium accumulated significant quantities of P. C, N and P were significant explanatory variables in determining changes in fungal community composition but explained <25% of the variation. Litter type was always a stronger factor than water table in determining either fungal community composition or turnover of C, N and P in litter. The results have implications for the ways restoration programmes and global climate change may impact upon nutrient cycling in cutover peatlands. PMID:18430005

Trinder, Clare J; Johnson, David; Artz, Rebekka R E

2008-06-01

52

Impact of Simulated Changes in Water Table Depth on Ex Situ Decomposition of Leaf Litter  

E-print Network

ARTICLE Impact of Simulated Changes in Water Table Depth on Ex Situ Decomposition of Leaf Litter of leaf litter after 12 weeks, with 31, 19 and 6 % less remaining in the non-flooded treatment for R, with fine litter input being margin- ally greater (Mahli et al. 2011). Decomposition of leaf litter

Bermingham, Eldredge

53

Modeling water use at thermoelectric power plants  

E-print Network

The withdrawal and consumption of water at thermoelectric power plants affects regional ecology and supply security of both water and electricity. The existing field data on US power plant water use, however, is of limited ...

Rutberg, Michael J. (Michael Jacob)

2012-01-01

54

Changes in bacterial and eukaryotic communities during sewage decomposition in Mississippi River water  

EPA Science Inventory

Microbial decay processes are one of the mechanisms whereby sewage contamination is reduced in the environment. This decomposition process involves a highly complex array of bacterial and eukaryotic communities from both sewage and ambient waters. However, relatively little is kn...

55

A Fast Iterated Conditional Modes Algorithm for Water–Fat Decomposition in MRI  

Microsoft Academic Search

Decomposition of water and fat in magnetic resonance imaging (MRI) is important for biomedical research and clinical applications. In this paper, we propose a two-phased approach for the three-point water-fat decomposition problem. Our contribu- tion consists of two components: 1) a background-masked Markov random field (MRF) energy model to formulate the local smooth- ness of field inhomogeneity; 2) a new

Fangping Huang; Sreenath Narayan; David Wilson; David Johnson; Guo-Qiang Zhang

2011-01-01

56

Seasonal decomposition of Typha latifolia in a free-water surface constructed wetland  

Microsoft Academic Search

Litter decomposition has important consequences on constructed wetlands because it is related to the autochthonous production of organic matter, clogging rates in surface-flow wetlands, and terrestrialization in free-water surface wetlands. Decomposition rates of Typha latifolia were quantified during both winter and summer in a free-water surface constructed wetland using the litter bag technique. Air-dried leaves and stems of Typha were

Juan A. Álvarez; Eloy Bécares

2006-01-01

57

ASSESSING POWER PLANT COOLING WATER INTAKE SYSTEM  

E-print Network

ASSESSING POWER PLANT COOLING WATER INTAKE SYSTEM ENTRAINMENT IMPACTS Prepared For: California power plants and other industrial facilities that withdraw cooling water from surface water bodies regulated under Section 316(b), steam electric power plants represent the largest cooling water volumes

58

The effect of living plants on root decomposition of four grass species  

Microsoft Academic Search

We tested whether living plant roots of Holcus lanatus and Festuca ovina can affect the decomposition rate of dead roots of Holcus lanatus, Festuca rubra, Anthoxanthum odoratum and Festuca ovina. Moreover, we investigated whether this effect is dependent on the decomposing root species or the nitrogen supply during the growth of the roots. The selected perennial grass species are typical

Krift van der T. A. J; Peter J. Kuikman; Frank Berendse

2002-01-01

59

Dry Season Decomposition of Leaf Litter from Five Common Plant Species of West Africa  

Microsoft Academic Search

The rates of decomposition of litter from five plant species common to West Africa namely: Chromolaena odorata (Siam weed), Anacardium occidentale (cashew), Acioa batteri, Imperata cylindrica (spear grass) and Pentaclethra macrophylla (oil bean) were investigated in the laboratory and the field during the dry season using respiration and litter bag techniques.There were significant differences (P< 0.05) amongst the species in

N. N. Agbim

1987-01-01

60

Temperature and plant species control over litter decomposition in Alaskan tundra  

Microsoft Academic Search

This study compared effects of increased temperature and litter from different Alaskan tundra plant species on cycling of carbon and nitrogen through litter and soil in microcosms. Warming between 4° and 10°C significantly increased rates of soil and litter respiration, litter decomposition, litter nitrogen release, and soil net nitrogen mineralization. Thus, future warming will directly increase rates of carbon and

Hobbie

1996-01-01

61

Effect of Water Vapor on Benzene Decomposition Using a Nonthermal-Discharge Plasma Reactor  

Microsoft Academic Search

The effect of water vapor on benzene decomposition in air was investigatedusing a nonthermal-discharge plasma reactor packed with ferroelectricmaterials. The conversion of benzene was found to decrease with an increaseof water concentration. On the other hand, the selectivity to CO2 in thedecomposition products increased with an increase of water concentration. Acomparison between the benzene conversion to CO and CO2 suggested

Atsushi Ogata; Noboru Shintani; Kazushi Yamanouchi; Koichi Mizuno; Satoshi Kushiyama; Toshiaki Yamamoto

2000-01-01

62

A FULLY IMPLICIT DOMAIN DECOMPOSITION ALGORITHM FOR SHALLOW WATER EQUATIONS ON THE CUBED-SPHERE  

E-print Network

. Key words. Shallow water equations, cubed-sphere, fully implicit method, domain decomposi- tionA FULLY IMPLICIT DOMAIN DECOMPOSITION ALGORITHM FOR SHALLOW WATER EQUATIONS ON THE CUBED-SPHERE CHAO YANG, JIANWEN CAO, AND XIAO-CHUAN CAI§ Abstract. Popular approaches for solving the shallow water

Cai, Xiao-Chuan

63

Noise Decomposition in Boiling Water Reactors with Application to Stability Monitoring  

E-print Network

Noise Decomposition in Boiling Water Reactors with Application to Stability Monitoring J. Karlsson in boiling water reactor (BWR) noise measure- ments, based on flux factorization techniques (i.e., using reactors4 or flux oscillations in boiling water reactors5,6 ~BWRs!. In these cases the different modes have

Pázsit, Imre

64

Plant diversity impacts decomposition and herbivory via changes in aboveground arthropods.  

PubMed

Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

Ebeling, Anne; Meyer, Sebastian T; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W

2014-01-01

65

(Plant growth with limited water)  

SciTech Connect

The work supported by DOE in the last year built on our earlier findings that stem growth in soybean subjected to limited water is inhibited first by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. With time, there is modest recovery in extensibility and a 28kD protein accumulates in the walls of the growth-affected cells. A 31kD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. Explorations of the mRNA for these proteins showed that the mRNA for the 28kD protein increased in the shoot in response to water deprivation but the mRNA for the 31kD protein did not accumulate. In contrast, the roots continued to grow and the mRNA for the 31kD protein accumulated but the mRNA for the 28kD protein was undetectable. We also explored how growth occurs in the absence of an external water supply. We found that, under these conditions, internal water is mobilized from surrounding nongrowing or slowly growing tissues and is used by rapidly growing cells. We showed that a low water potential is normally present in the enlarging tissues and is the likely force that extracts water from the surrounding tissues. We found that it involved a gradient in water potential that extended from the xylem to the outlying cells in the enlarging region and was not observed in the slowly growing basal tissue of the stems of the same plant. The gradient was measured directly with single cell determinations of turgor and osmotic potential in intact plants. The gradient may explain instances of growth inhibition with limited water when there is no change in the turgor of the enlarging cells. 17 refs.

Not Available

1991-01-01

66

Plant water relations I: uptake and transport  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants, like all living things, are mostly water. Water is the matrix of life, and its availability determines the distribution and productivity of plants on earth. Vascular plants evolved structures that enable them to transport water long distances with little input of energy, but the hollow trach...

67

Quality assessment of plant transpiration water  

NASA Technical Reports Server (NTRS)

It has been proposed to use plants as elements of biologically-based life support systems for long-term space missions. Three roles have been brought forth for plants in this application: recycling of water, regeneration of air and production of food. This report discusses recycling of water and presents data from investigations of plant transpiration water quality. Aqueous nutrient solution was applied to several plant species and transpired water collected. The findings indicated that this water typically contained 0.3-6 ppm of total organic carbon, which meets hygiene water standards for NASA's space applications. It suggests that this method could be developed to achieve potable water standards.

Macler, Bruce A.; Janik, Daniel S.; Benson, Brian L.

1990-01-01

68

Glucose and fructose decomposition in subcritical and supercritical water: Detailed reaction pathway, mechanisms, and kinetics  

SciTech Connect

The authors are developing a new catalyst-free process of cellulose decomposition in supercritical water. In their initial study on the cellulose decomposition in supercritical water, the main products of cellulose decomposition were found to be oligomers of glucose (cellobiose, cellotriose, etc.) and glucose at short residence times (400 C, 25 MPa, 0.05 s). The kinetics of glucose at these conditions can be useful in understanding the reaction pathways of cellulose. Experiments were performed on the products of glucose decomposition at short residence times to elucidate the reaction pathways and evaluate kinetics of glucose and fructose decomposition in sub- and supercritical water. The conditions were a temperature of 300--400 C and pressure of 25--40 MPa for extremely short residence times between 0.02 and 2 s. The products of glucose decomposition were fructose, a product of isomerization, 1,6-anhydroglucose, a product of dehydration, and erythrose and glyceraldehyde, products of C-C bond cleavage. Fructose underwent reactions similar to glucose except that it did not form 1,6-anhydroglucose and isomerization to glucose is negligible. The mechanism for the products formed from C-C bond cleavage could be explained by reverse aldol condensation and the double-bond rule of the respective enediols formed during the Lobry de Bruyn Alberda van Ekenstein transformation. The differential equations resulting from the proposed pathways were fit to experimental results to obtain the kinetic rate constants.

Kabyemela, B.M.; Adschiri, T.; Malaluan, R.M.; Arai, K. [Tohoku Univ., Sendai (Japan). Dept. of Chemical Engineering] [Tohoku Univ., Sendai (Japan). Dept. of Chemical Engineering

1999-08-01

69

Hydrothermal decomposition of liquid crystal in subcritical water.  

PubMed

Treatment of liquid crystal has important significance for the environment protection and human health. This study proposed a hydrothermal process to decompose the liquid crystal of 4-octoxy-4'-cyanobiphenyl. Experiments were conducted with a 5.7 mL stainless tube reactor and heated by a salt-bath. Factors affecting the decomposition rate of 4-octoxy-4'-cyanobiphenyl were evaluated with HPLC. The decomposed liquid products were characterized by GC-MS. Under optimized conditions i.e., 0.2 mL H2O2 supply, pH value 6, temperature 275°C and reaction time 5 min, 97.6% of 4-octoxy-4'-cyanobiphenyl was decomposed into simple and environment-friendly products. Based on the mechanism analysis and products characterization, a possible hydrothermal decomposition pathway was proposed. The results indicate that hydrothermal technology is a promising choice for liquid crystal treatment. PMID:24632487

Zhuang, Xuning; He, Wenzhi; Li, Guangming; Huang, Juwen; Lu, Shangming; Hou, Lianjiao

2014-04-30

70

Temperature and plant species control over litter decomposition in Alaskan tundra  

SciTech Connect

This study compared effects of increased temperature and litter from different Alaskan tundra plant species on cycling of carbon and nitrogen through litter and soil in microcosms. Warming between 4{degrees} and 10{degrees}C significantly increased rates of soil and litter respiration, litter decomposition, litter nitrogen release, and soil net nitrogen mineralization. Thus, future warming will directly increase rates of carbon and nitrogen cycling through litter and soil in tundra. In addition, differences among species` litter in rates of decomposition, N release, and effects on soil net nitrogen mineralization were sometimes larger than differences between the two temperature treatments within a species. Thus, changes in plant community structure and composition associated with future warming will have important consequences for how elements cycle through litter and soil in tundra. In general, species within a growth form (graminoids, evergreen shrubs, deciduous shrubs, and mosses) were more similar in their effects on decomposition than were species belonging to different growth forms, with gramminoid litter having the fastest rate and litter of deciduous shrubs and mosses having the slowest rates. Differences in rates of litter decomposition were more related to carbon quality than to nitrogen concentration. Increased abundance of deciduous shrubs with future climate warming will promote carbon storage, because of their relatively large allocation to woody stems that decompose slowly. Changes in moss abundance will also have important consequences for future carbon and nitrogen cycling, since moss litter is extremely recalcitrant and has a low potential to immobilize nitrogen. 82 refs., 8 figs., 7 tabs.

Hobbie, S.E. [Univ. of California, Berkeley, CA (United States)

1996-11-01

71

Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use  

PubMed Central

Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna) were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity. PMID:25780777

Falco, Liliana B.; Sandler, Rosana V.; Coviella, Carlos E.

2015-01-01

72

Use of solar energy for direct and two-step water decomposition cycles  

Microsoft Academic Search

The feasibility of using concentrated solar energy at high temperatures to decompose water is experimentally demonstrated. Preliminary studies show that direct decomposition of water at 2000-2500 C is possible and that the main development should be directed toward reactor design and the separation of product gases. On the other hand, it is shown that two-step thermochemical cycles for hydrogen production

E. Bilgen; M. Ducarroir; M. Foex; F. Sibieude; F. Trombe

1977-01-01

73

Photogeneration of active formate decomposition catalysts to produce hydrogen from formate and water  

DOEpatents

A process for producing hydrogen from formate and water by photogenerating an active formate decomposition catalyst from transition metal carbonyl precursor catalysts at relatively low temperatures and otherwise mild conditions is disclosed. Additionally, this process may be expanded to include the generation of formate from carbon monoxide and hydroxide such that the result is the water gas shift reaction.

King, Jr., Allen D. (Athens, GA); King, Robert B. (Athens, GA); Sailers, III, Earl L. (Athens, GA)

1983-02-08

74

Water Treatment Technology - General Plant Operation.  

ERIC Educational Resources Information Center

One of twelve water treatment technology units, this student manual on general plant operations provides instructional materials for seven competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: water supply regulations, water plant…

Ross-Harrington, Melinda; Kincaid, G. David

75

Water Balance in Terrestrial PlantsWater Balance in Terrestrial Plants Water Regulation on LandWater Regulation on Land --PlantsPlants WWipip= W= Wrr + W+ Waa --WWtt --WWss  

E-print Network

1 Water Balance in Terrestrial PlantsWater Balance in Terrestrial Plants Water Regulation on LandWater waters internal water WWrr =Roots=Roots WWaa = Air= Air WWtt = Transpiration= Transpiration WWss = Secretions= Secretions Water Regulation on Land - Plants Water Balance in Terrestrial PlantsWater Balance

Cochran-Stafira, D. Liane

76

Kinetics of glucose epimerization and decomposition in subcritical and supercritical water  

SciTech Connect

Glucose decomposition kinetics in subcritical and supercritical water were studied for the temperatures 573, 623, and 673 K, pressures between 25 and 40 MPa, and residence times between 0.02 and 2 s. Glucose decomposition products were fructose, saccharinic acids, erythrose, glyceraldehyde, 1,6-anhydroglucose, dihydroxyacetone, pyruvaldehyde, and small amounts of 5-hydroxymethylfurfural. Fructose was also studied and found to decompose to products similar to those of glucose, except that its epimerization to glucose was negligibly low and no formation of 1,6-anhydroglucose was detected. The authors concluded that only the forward epimerization of glucose to fructose was important. The glucose decomposition pathway could be described in terms of a forward epimerization rate, r{sub gf}, a fructose to decomposition products rate, r{sub f}, and a glucose to decomposition products rate, r{sub g}. A kinetic model based on this pathway gave good correlation of the experimental data. In the subcritical region, r{sub g}, r{sub f}, and r{sub gf} showed only small changes with pressure at a given temperature. In the supercritical region, the rate of glucose decomposition decreased with pressure at a given temperature. The reason for this decrease was mainly due to the decrease in r{sub gf}. The pressure effect in the supercritical region shows that there is a shift among the kinetic rates, which can lead to higher selectivity for glucose when decomposing cellulosic materials.

Kabyemela, B.M.; Adschiri, Tadafumi; Malaluan, R.M.; Arai, Kunio [Tohoku Univ., Sendai (Japan). Dept. of Chemical Engineering] [Tohoku Univ., Sendai (Japan). Dept. of Chemical Engineering

1997-05-01

77

Response of plants to water stress  

PubMed Central

Water stress adversely impacts many aspects of the physiology of plants, especially photosynthetic capacity. If the stress is prolonged, plant growth, and productivity are severely diminished. Plants have evolved complex physiological and biochemical adaptations to adjust and adapt to a variety of environmental stresses. The molecular and physiological mechanisms associated with water-stress tolerance and water-use efficiency have been extensively studied. The systems that regulate plant adaptation to water stress through a sophisticated regulatory network are the subject of the current review. Molecular mechanisms that plants use to increase stress tolerance, maintain appropriate hormone homeostasis and responses and prevent excess light damage, are also discussed. An understanding of how these systems are regulated and ameliorate the impact of water stress on plant productivity will provide the information needed to improve plant stress tolerance using biotechnology, while maintaining the yield and quality of crops. PMID:24659993

Osakabe, Yuriko; Osakabe, Keishi; Shinozaki, Kazuo; Tran, Lam-Son P.

2014-01-01

78

Radiation induced decomposition of chlorinated phenols in water  

NASA Astrophysics Data System (ADS)

Experiments with 4-Cl-phenol as a model compound for pesticides were performed under steady-state conditions using deoxygenated solutions as well as such saturated with air, oxygen or oxygen mixed with ozone. The yield of Cl -ions serviced as an indicator for the degradation process. As main products of the first step of decomposition were identified: polyhydroxybenzenes, aldehydes and acids. The yield of aldehydes was studied as a function of the absorbed dose and substrate concentration. In the presence of ozone a chain-reaction of the oxidative pollutant degradation takes place. Transient absorption spectra and kinetics obtained by preliminary pulse radiolysis studies of 4-Cl-phenol in the presence of oxygen as well as probable reaction mechanisms are also presented.

Getoff, N.; Solar, S.

79

Scale decomposition of atmospheric water budget over West Africa during the monsoon 2006 from NCEP/GFS analyses  

E-print Network

Scale decomposition of atmospheric water budget over West Africa during the monsoon 2006 from NCEP the terms of the atmospheric water budget over West Africa using a dedicated decomposition methodology scales of seasonal mean precipitation and moisture flux divergence over West Africa during the monsoon

Roca, Rémy

80

Reconciling Phylogeny and Function During Plant Litter Decomposition by High-Throughput Functional Metagenomics  

NASA Astrophysics Data System (ADS)

Integrating information on microbial diversity and functionality with ecosystem processes may be critical to predicting how ecosystems respond to environmental change. While theoretical models can be used to link microbial processes to environmental responses and rates, accurate predictions of ecosystem functioning would benefit from detailed information on microbial community composition and function. In this study, our aim was to identify functional traits involved in plant litter decomposition, a model process for carbon cycling, from decomposing plant litter. The overall goal is then to link these traits with individual microbial taxa and use this information to build predictive trait-based models of ecosystem responses to global change. In order to identify activities involved in plant litter decomposition we used automated high-throughput assays for functional screening of metagenomic fosmid libraries prepared from decomposing plant litter. Litter was collected over 15 month period from a global change field experiment undergoing rainfall and nitrogen manipulations. We identified over 600 cellulose, hemicellulose, chitin and starch hydrolyzing clones following screening of over 300,000 clones. The frequency of positive clones was ten times lower during dry season but no significant differences in hit rates were observed between different treatments. The positive clones were shotgun sequenced on the Illumina sequencing platform and the identified hydrolytic genes were shown to represent variety bacterial taxonomic groups including Proteobacteria and Bacteroidetes.

Nyyssonen, M.; Weihe, C.; Goulden, M.; Treseder, K. K.; Martiny, J.; Martiny, A.; Allison, S. D.; Brodie, E. L.

2012-12-01

81

Additive Effect of Water on the Decomposition of VOCs in Nonthermal Plasma  

Microsoft Academic Search

In the removal of volatile organic compounds (VOCs) with nonthermal plasma (NTP), gaseous oxygen is mandatory to oxidatively decompose VOCs. On the other hand, there have been disputed discussions on the additive effect of water in the decomposition of VOCs in NTP, but a unified mechanism has not been established yet. Both of VOC conversion and carbon balance can be

Masami Sugasawa; Tomoyuki Terasawa; Shigeru Futamura

2008-01-01

82

Studies on the decomposition behavior of nylon-66 in supercritical water  

Microsoft Academic Search

Water was used for the decomposition of nylon-66. Gas chromatography (GC) and Mass spectrometry (MS) analytic techniques were employed to identify the composition of received products. Quantitative analyses were performed by gas chromatography and high performance liquid chromatography (HPLC). The results showed that after 30 min at conditions of 380 °C, 28 MPa nylon-66 was completely decomposed and there were no

Linghui Meng; Yan Zhang; Yudong Huang; Mitsuhiro Shibata; Ryutoku Yosomiya

2004-01-01

83

Wetlands: water, wildlife, plants, & people  

USGS Publications Warehouse

Wetlands are part of all our lives. They can generally be described as transitional areas between land and deepwater habitats. There are many different kinds of wetlands, and they can be found in many different habitat types, from forests to deserts; some are maintained by saltwater, others by freshwater. This poster shows general types of diverse wetlands and demonstrates how people and wetlands can benefit by living together. The diversity of plants and animals is shown in cartooned pictures. As with plants and animals, there are many different common names for the various wetland types. The common names used on this poster were used by the U.S. Fish and Wildlife Service in the publication "Wetlands-Status and Trends in the Conterminous United States, Mid-1970's to Mid-1980's." Estuarine wetland types--salt marshes and mangrove swamps--are labeled in red letters. The estuary is where ocean saltwater and river freshwater mix. The estuary is labeled in orange letters. The inland wetland types-inland marshes and wet meadows, forested wetlands, and shrub wetlands-are labeled in yellow. Other wetlands are present in rivers, lakes, and reservoirs. The water bodies associated with these wetlands are labeled in black. The poster is folded into 8.5" x 11" panels; front and back panels can easily be photocopied.

Vandas, Stephen; Farrar, Frank, (artist)

1996-01-01

84

Thermochemical water decomposition. [hydrogen separation for energy applications  

NASA Technical Reports Server (NTRS)

At present, nearly all of the hydrogen consumed in the world is produced by reacting hydrocarbons with water. As the supply of hydrocarbons diminishes, the problem of producing hydrogen from water alone will become increasingly important. Furthermore, producing hydrogen from water is a means of energy conversion by which thermal energy from a primary source, such as solar or nuclear fusion of fission, can be changed into an easily transportable and ecologically acceptable fuel. The attraction of thermochemical processes is that they offer the potential for converting thermal energy to hydrogen more efficiently than by water electrolysis. A thermochemical hydrogen-production process is one which requires only water as material input and mainly thermal energy, or heat, as an energy input. Attention is given to a definition of process thermal efficiency, the thermodynamics of the overall process, the single-stage process, the two-stage process, multistage processes, the work of separation and a process evaluation.

Funk, J. E.

1977-01-01

85

Water protection in coke-plant design  

SciTech Connect

Wastewater generation, water consumption, and water management at coke plants are considered. Measures to create runoff-free water-supply and sewer systems are discussed. Filters for water purification, corrosion inhibitors, and biocides are described. An integrated single-phase technology for the removal of phenols, thiocyanides, and ammoniacal nitrogen is outlined.

G.I. Alekseev [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

2009-07-15

86

Daily water level forecasting using wavelet decomposition and artificial intelligence techniques  

NASA Astrophysics Data System (ADS)

Reliable water level forecasting for reservoir inflow is essential for reservoir operation. The objective of this paper is to develop and apply two hybrid models for daily water level forecasting and investigate their accuracy. These two hybrid models are wavelet-based artificial neural network (WANN) and wavelet-based adaptive neuro-fuzzy inference system (WANFIS). Wavelet decomposition is employed to decompose an input time series into approximation and detail components. The decomposed time series are used as inputs to artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) for WANN and WANFIS models, respectively. Based on statistical performance indexes, the WANN and WANFIS models are found to produce better efficiency than the ANN and ANFIS models. WANFIS7-sym10 yields the best performance among all other models. It is found that wavelet decomposition improves the accuracy of ANN and ANFIS. This study evaluates the accuracy of the WANN and WANFIS models for different mother wavelets, including Daubechies, Symmlet and Coiflet wavelets. It is found that the model performance is dependent on input sets and mother wavelets, and the wavelet decomposition using mother wavelet, db10, can further improve the efficiency of ANN and ANFIS models. Results obtained from this study indicate that the conjunction of wavelet decomposition and artificial intelligence models can be a useful tool for accurate forecasting daily water level and can yield better efficiency than the conventional forecasting models.

Seo, Youngmin; Kim, Sungwon; Kisi, Ozgur; Singh, Vijay P.

2015-01-01

87

Complementary symbiont contributions to plant decomposition in a fungus-farming termite.  

PubMed

Termites normally rely on gut symbionts to decompose organic matter but the Macrotermitinae domesticated Termitomyces fungi to produce their own food. This transition was accompanied by a shift in the composition of the gut microbiota, but the complementary roles of these bacteria in the symbiosis have remained enigmatic. We obtained high-quality annotated draft genomes of the termite Macrotermes natalensis, its Termitomyces symbiont, and gut metagenomes from workers, soldiers, and a queen. We show that members from 111 of the 128 known glycoside hydrolase families are represented in the symbiosis, that Termitomyces has the genomic capacity to handle complex carbohydrates, and that worker gut microbes primarily contribute enzymes for final digestion of oligosaccharides. This apparent division of labor is consistent with the Macrotermes gut microbes being most important during the second passage of comb material through the termite gut, after a first gut passage where the crude plant substrate is inoculated with Termitomyces asexual spores so that initial fungal growth and polysaccharide decomposition can proceed with high efficiency. Complex conversion of biomass in termite mounds thus appears to be mainly accomplished by complementary cooperation between a domesticated fungal monoculture and a specialized bacterial community. In sharp contrast, the gut microbiota of the queen had highly reduced plant decomposition potential, suggesting that mature reproductives digest fungal material provided by workers rather than plant substrate. PMID:25246537

Poulsen, Michael; Hu, Haofu; Li, Cai; Chen, Zhensheng; Xu, Luohao; Otani, Saria; Nygaard, Sanne; Nobre, Tania; Klaubauf, Sylvia; Schindler, Philipp M; Hauser, Frank; Pan, Hailin; Yang, Zhikai; Sonnenberg, Anton S M; de Beer, Z Wilhelm; Zhang, Yong; Wingfield, Michael J; Grimmelikhuijzen, Cornelis J P; de Vries, Ronald P; Korb, Judith; Aanen, Duur K; Wang, Jun; Boomsma, Jacobus J; Zhang, Guojie

2014-10-01

88

Complementary symbiont contributions to plant decomposition in a fungus-farming termite  

PubMed Central

Termites normally rely on gut symbionts to decompose organic matter but the Macrotermitinae domesticated Termitomyces fungi to produce their own food. This transition was accompanied by a shift in the composition of the gut microbiota, but the complementary roles of these bacteria in the symbiosis have remained enigmatic. We obtained high-quality annotated draft genomes of the termite Macrotermes natalensis, its Termitomyces symbiont, and gut metagenomes from workers, soldiers, and a queen. We show that members from 111 of the 128 known glycoside hydrolase families are represented in the symbiosis, that Termitomyces has the genomic capacity to handle complex carbohydrates, and that worker gut microbes primarily contribute enzymes for final digestion of oligosaccharides. This apparent division of labor is consistent with the Macrotermes gut microbes being most important during the second passage of comb material through the termite gut, after a first gut passage where the crude plant substrate is inoculated with Termitomyces asexual spores so that initial fungal growth and polysaccharide decomposition can proceed with high efficiency. Complex conversion of biomass in termite mounds thus appears to be mainly accomplished by complementary cooperation between a domesticated fungal monoculture and a specialized bacterial community. In sharp contrast, the gut microbiota of the queen had highly reduced plant decomposition potential, suggesting that mature reproductives digest fungal material provided by workers rather than plant substrate. PMID:25246537

Hu, Haofu; Li, Cai; Chen, Zhensheng; Otani, Saria; Nygaard, Sanne; Nobre, Tania; Klaubauf, Sylvia; Schindler, Philipp M.; Hauser, Frank; Pan, Hailin; Yang, Zhikai; Sonnenberg, Anton S. M.; de Beer, Z. Wilhelm; Zhang, Yong; Wingfield, Michael J.; Grimmelikhuijzen, Cornelis J. P.; de Vries, Ronald P.; Korb, Judith; Aanen, Duur K.; Wang, Jun; Boomsma, Jacobus J.; Zhang, Guojie

2014-01-01

89

Upgrading a Landmark Water Treatment Plant  

Microsoft Academic Search

By 1982, rapid growth in the metropolitan area of Tampa, Fla., had increased the demand for water beyond the capacity of the city's only water treatment plant. Designated an AWWA American Landmark, the Hillsborough River plant had been enlarged three times previously since its constructionin 1925. The latest expansion, which was completed last year, added 36 mgd (136,000 m³\\/d) of

James G. Smith; David L. Tippin; Malichi C. Bennet III; Jagdish B. Salgaonkar

1987-01-01

90

Find Out How Plants Use Water  

NSDL National Science Digital Library

In this activity, learners investigate how plants use water. By making the flowers change color, learners see how water moves up the stem to the leaves and the flowers. Use this activity to discuss the structure of plants and the nutrients they need to survive. Safety note: young learners should get an adult to help them trim the stems of the flowers.

DynaMo

2012-01-01

91

Regulation of Water in Plant Cells  

ERIC Educational Resources Information Center

Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

Kowles, Richard V.

2010-01-01

92

Genotypic diversity of an invasive plant species promotes litter decomposition and associated processes.  

PubMed

Following studies that showed negative effects of species loss on ecosystem functioning, newer studies have started to investigate if similar consequences could result from reductions of genetic diversity within species. We tested the influence of genotypic richness and dissimilarity (plots containing one, three, six or 12 genotypes) in stands of the invasive plant Solidago canadensis in China on the decomposition of its leaf litter and associated soil animals over five monthly time intervals. We found that the logarithm of genotypic richness was positively linearly related to mass loss of C, N and P from the litter and to richness and abundance of soil animals on the litter samples. The mixing proportion of litter from two sites, but not genotypic dissimilarity of mixtures, had additional effects on measured variables. The litter diversity effects on soil animals were particularly strong under the most stressful conditions of hot weather in July: at this time richness and abundance of soil animals were higher in 12-genotype litter mixtures than even in the highest corresponding one-genotype litter. The litter diversity effects on decomposition were in part mediated by soil animals: the abundance of Acarina, when used as covariate in the analysis, fully explained the litter diversity effects on mass loss of N and P. Overall, our study shows that high genotypic richness of S. canadensis leaf litter positively affects richness and abundance of soil animals, which in turn accelerate litter decomposition and P release from litter. PMID:24276771

Wang, Xiao-Yan; Miao, Yuan; Yu, Shuo; Chen, Xiao-Yong; Schmid, Bernhard

2014-03-01

93

Purchasing Compost Compost, the end product of a controlled decomposition of plant and animal wastes, makes an excellent addition  

E-print Network

Purchasing Compost Compost, the end product of a controlled decomposition of plant and animal wastes, makes an excellent addition to lawn or garden soil. Adding compost to your soil helps improve both its drainage and waterholding properties. Compost stores plant nutrients and prevents them from

New Hampshire, University of

94

Litter type, but not plant cover, regulates initial litter decomposition and fungal community structure in a recolonising cutover peatland  

Microsoft Academic Search

Cutover peatlands are often rapidly colonised by pioneer plant species, which have the potential to affect key ecosystem processes such as carbon (C) turnover. The aim of this study was to investigate how plant cover and litter type affect fungal community structure and litter decomposition in a cutover peatland. Intact cores containing Eriophorum vaginatum, Eriophorum angustifolium, Calluna vulgaris and bare

Clare J. Trinder; David Johnson; Rebekka R. E. Artz

2009-01-01

95

New tantalate photocatalysts for water decomposition into H 2 and O 2  

NASA Astrophysics Data System (ADS)

Photocatalytic activities for the decomposition of distilled water into H 2 and O 2 were investigated on various tantalates. In the alkali and alkaline earth tantalates, LiTaO 3, NaTaO 3, KTaO 3, MgTa 2O 6, and BaTa 2O 6 showed photocatalytic activities for water decomposition without co-catalysts. Among them, BaTa 2O 6 in the orthorhombic phase was the most active. The addition of a small amount of Ba(OH) 2 into the water and supporting NiO drastically enhanced the photocatalytic reaction on the BaTa 2O 6 catalyst. On the other hand, in the transition metal tantalates, NiTa 2O 6 produced both H 2 and O 2 without co-catalysts.

Kato, Hideki; Kudo, Akihiko

1998-10-01

96

Solar hydrogen production by direct water decomposition process - A preliminary engineering assessment  

NASA Astrophysics Data System (ADS)

A direct water decomposition solar heat module is presented which can produce about 100 mole H2/hour, and consists of a heliostatic parabolic concentrator, a double receiver, and the necessary power conversion cycle. The double receiver's high temperature cavity can collect solar heat at temperatures as high as 2500 K. Overall solar energy collection efficiency is about 70 percent. Direct decomposition and separation techniques are discussed which employ high temperature membrane separation and either steam or water quenching, followed by low temperature gas separation. It is found tha the overall efficiency of solar hydrogen production from a module will be 6.4-8.8 percent, depending on the process used. The water quenching process may be the simplest of the alternatives considered.

Bilgen, E.

97

Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications  

NASA Astrophysics Data System (ADS)

Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood ( Avicennia germinans), cypress needles and wood ( Taxodium distichum) and smooth cordgrass ( Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39, and 93%, respectively. Analysis of the lignin component of herbaceous tissues using alkaline CuO oxidation was complicated by the presence of a substantial ester-bound phenol component composed primarily of cinnamyl phenols. To overcome this problem, we introduce a new parameter to represent lignin, ?6. ?6 is comprised only of the six syringyl and vanillyl phenols and was found to be much less sensitive to diagenetic variation than the commonly used parameter ?, which includes the cinnamyl phenols. Patterns of change in lignin content were strongly dependent on tissue type, ranging from 77% enrichment in smooth cordgrass to 6% depletion in cypress needles. In contrast, depletion of cutin was extensive (65-99%) in all herbaceous tissues. Despite these differences in the overall reactivity of lignin and cutin, both macromolecules were extensively degraded during the decomposition period. The long-term decomposition series also provided very useful information about the compositional parameters which are derived from the specific oxidation products of both lignin and cutin. The relative lability of ester-bound cinnamyl phenols compromised their use in parameters to distinguish woody from herbaceous plant debris. The dimer to monomer ratios of lignin-derived phenols indicated that most intermonomeric linkages in lignin degraded at similar rates. Acid to aldehyde ratios of vanillyl and syringyl phenols became elevated, particularly during the latter stages of decomposition supporting the use of these parameters as indicators of diagenetic alteration. Given the observation that cutin-derived source indicator parameters were generally more sensitive to diagenetic alteration than those of lignin, we suggest the distributional patterns of cutin-derived acids and their associated positional isomers may be most useful for tissue-specific distinctions complementing the general categorical information obtained from lignin phenol analysis alone.

Opsahl, Stephen; Benner, Ronald

1995-12-01

98

Carbon availability triggers the decomposition of plant litter and assimilation of nitrogen by an ectomycorrhizal fungus.  

PubMed

The majority of nitrogen in forest soils is found in organic matter-protein complexes. Ectomycorrhizal fungi (EMF) are thought to have a key role in decomposing and mobilizing nitrogen from such complexes. However, little is known about the mechanisms governing these processes, how they are regulated by the carbon in the host plant and the availability of more easily available forms of nitrogen sources. Here we used spectroscopic analyses and transcriptome profiling to examine how the presence or absence of glucose and/or ammonium regulates decomposition of litter material and nitrogen mobilization by the ectomycorrhizal fungus Paxillus involutus. We found that the assimilation of nitrogen and the decomposition of the litter material are triggered by the addition of glucose. Glucose addition also resulted in upregulation of the expression of genes encoding enzymes involved in oxidative degradation of polysaccharides and polyphenols, peptidases, nitrogen transporters and enzymes in pathways of the nitrogen and carbon metabolism. In contrast, the addition of ammonium to organic matter had relatively minor effects on the expression of transcripts and the decomposition of litter material, occurring only when glucose was present. On the basis of spectroscopic analyses, three major types of chemical modifications of the litter material were observed, each correlated with the expression of specific sets of genes encoding extracellular enzymes. Our data suggest that the expression of the decomposition and nitrogen assimilation processes of EMF can be tightly regulated by the host carbon supply and that the availability of inorganic nitrogen as such has limited effects on saprotrophic activities. PMID:23788332

Rineau, F; Shah, F; Smits, M M; Persson, P; Johansson, T; Carleer, R; Troein, C; Tunlid, A

2013-10-01

99

Carbon availability triggers the decomposition of plant litter and assimilation of nitrogen by an ectomycorrhizal fungus  

PubMed Central

The majority of nitrogen in forest soils is found in organic matter–protein complexes. Ectomycorrhizal fungi (EMF) are thought to have a key role in decomposing and mobilizing nitrogen from such complexes. However, little is known about the mechanisms governing these processes, how they are regulated by the carbon in the host plant and the availability of more easily available forms of nitrogen sources. Here we used spectroscopic analyses and transcriptome profiling to examine how the presence or absence of glucose and/or ammonium regulates decomposition of litter material and nitrogen mobilization by the ectomycorrhizal fungus Paxillus involutus. We found that the assimilation of nitrogen and the decomposition of the litter material are triggered by the addition of glucose. Glucose addition also resulted in upregulation of the expression of genes encoding enzymes involved in oxidative degradation of polysaccharides and polyphenols, peptidases, nitrogen transporters and enzymes in pathways of the nitrogen and carbon metabolism. In contrast, the addition of ammonium to organic matter had relatively minor effects on the expression of transcripts and the decomposition of litter material, occurring only when glucose was present. On the basis of spectroscopic analyses, three major types of chemical modifications of the litter material were observed, each correlated with the expression of specific sets of genes encoding extracellular enzymes. Our data suggest that the expression of the decomposition and nitrogen assimilation processes of EMF can be tightly regulated by the host carbon supply and that the availability of inorganic nitrogen as such has limited effects on saprotrophic activities. PMID:23788332

Rineau, F; Shah, F; Smits, M M; Persson, P; Johansson, T; Carleer, R; Troein, C; Tunlid, A

2013-01-01

100

Influence of soil temperature and water tension on the decomposition rate of ¹⁴Ca labeled herbage  

Microsoft Academic Search

The relation of decomposition rate of carbon-14 labeled blue grama (Bouteloua gracilis) to soil water content and temperature was examined in laboratory studies. Soil samples amended with ground herbage were incubated at various temperatures (3, 10, 25, 40, 50, and 60°C and water contents (.009, .03, .06, .60, 5.8, and 113 atm water tension). The oxygen concentrations in the decomposition

J. W. NYHAN

1976-01-01

101

Decomposition of Phragmites australis rhizomes in artificial land-water transitional zones (ALWTZs) and management implications  

NASA Astrophysics Data System (ADS)

Rhizomes are essential organs for growth and expansion of Phragmites australis. They function as an important source of organic matter and as a nutrient source, especially in the artificial land-water transitional zones (ALWTZs) of shallow lakes. In this study, decomposition experiments on 1- to 6-year-old P. australis rhizomes were conducted in the ALWTZ of Lake Baiyangdian to evaluate the contribution of the rhizomes to organic matter accumulation and nutrient release. Mass loss and changes in nutrient content were measured after 3, 7, 15, 30, 60, 90, 120, and 180 days. The decomposition process was modeled with a composite exponential model. The Pearson correlation analysis was used to analyze the relationships between mass loss and litter quality factors. A multiple stepwise regression model was utilized to determine the dominant factors that affect mass loss. Results showed that the decomposition rates in water were significantly higher than those in soil for 1- to 6-year-old rhizomes. However, the sequence of decomposition rates was identical in both water and soil. Significant relationships between mass loss and litter quality factors were observed at a later stage, and P-related factors proved to have a more significant impact than N-related factors on mass loss. According to multiple stepwise models, the C/P ratio was found to be the dominant factor affecting the mass loss in water, and the C/N and C/P ratios were the main factors affecting the mass loss in soil. The combined effects of harvesting, ditch broadening, and control of water depth should be considered for lake administrators.

Han, Zhen; Cui, Baoshan; Zhang, Yongtao

2015-02-01

102

Method of generating hydrogen by catalytic decomposition of water  

DOEpatents

A method for producing hydrogen includes providing a feed stream comprising water; contacting at least one proton conducting membrane adapted to interact with the feed stream; splitting the water into hydrogen and oxygen at a predetermined temperature; and separating the hydrogen from the oxygen. Preferably the proton conducting membrane comprises a proton conductor and a second phase material. Preferable proton conductors suitable for use in a proton conducting membrane include a lanthanide element, a Group VIA element and a Group IA or Group IIA element such as barium, strontium, or combinations of these elements. More preferred proton conductors include yttrium. Preferable second phase materials include platinum, palladium, nickel, cobalt, chromium, manganese, vanadium, silver, gold, copper, rhodium, ruthenium, niobium, zirconium, tantalum, and combinations of these. More preferably second phase materials suitable for use in a proton conducting membrane include nickel, palladium, and combinations of these. The method for generating hydrogen is preferably preformed in the range between about 600.degree. C. and 1,700.degree. C.

Balachandran, Uthamalingam (Hinsdale, IL); Dorris, Stephen E. (LaGrange Park, IL); Bose, Arun C. (Pittsburgh, PA); Stiegel, Gary J. (Library, PA); Lee, Tae-Hyun (Naperville, IL)

2002-01-01

103

Heterogeneous catalyzed decomposition reactions of dichlorodifluoromethane in the presence of water on ?-alumina  

Microsoft Academic Search

The heterogeneous catalyzed decomposition of CCl2F2 (CFC-12) in the presence of water was investigated, employing ?-alumina as catalyst. The catalyzed hydrolysis reaction yields very high conversion degrees of CFC-12 in the first reaction stage. For a period of about 3 h there is a remarkable lack of balance between the amount of liberated HF and HCl owing to the uptake

E. Kemnitz; A. Kohne; E. Lieske

1997-01-01

104

Aquatic Plant Water Quality Criteria  

EPA Science Inventory

The USEPA, as stated in the Clean Water Act, is tasked with developing numerical Aquatic Life Critiera for various pollutants found in the waters of the United States. These criteria serve as guidance for States and Tribes to use in developing their water quality standards. The G...

105

Combining experiment and theory to elucidate the role of supercritical water in sulfide decomposition.  

PubMed

The cleavage of C-S linkages plays a key role in fuel processing and organic geochemistry. Water is known to affect these processes, and several hypotheses have been proposed, but the mechanism has been elusive. Here we use both experiment and theory to demonstrate that supercritical water reacts with intermediates formed during alkyl sulfide decomposition. During hexyl sulfide decomposition in supercritical water, pentane and CO + CO2 were detected in addition to the expected six carbon products. A multi-step reaction sequence for hexyl sulfide reacting with supercritical water is proposed which explains the surprising products, and quantum chemical calculations provide quantitative rates that support the proposed mechanism. The key sequence is cleavage of one C-S bond to form a thioaldehyde via radical reactions, followed by a pericyclic addition of water to the C[double bond, length as m-dash]S bond to form a geminal mercaptoalcohol. The mercaptoalcohol decomposes into an aldehyde and H2S either directly or via a water-catalyzed 6-membered ring transition state. The aldehyde quickly decomposes into CO plus pentane by radical reactions. The time is ripe for quantitative modelling of organosulfur reaction kinetics based on modern quantum chemistry. PMID:24728624

Kida, Yuko; Class, Caleb A; Concepcion, Anthony J; Timko, Michael T; Green, William H

2014-05-28

106

Water reclamation plant (RealVideo)  

NSDL National Science Digital Library

In this video clip, students see how wastewater is treated at a water reclamation plant. One of the plant's operators gives Bob the Vid Tec (a children's programming host) a tour of the plant, describing along the way what happens at each step in the water treatment process. For example, the operator explains that microorganisms are used to consume human waste in the biological nutrient removal step. Bob also talks with another plant operator about why kids should learn about wastewater treatment. Both of the operators discuss the problems that grease and cooking oil create for water treatment. Students are reminded that usable water is a limited resource that should be safeguarded. Copyright 2005 Eisenhower National Clearinghouse

Johns Hopkins University. Center for Technology in Education (CTE)

2004-01-01

107

Water/Wastewater Treatment Plant Operator Qualifications.  

ERIC Educational Resources Information Center

This article summarizes in tabular form the U.S. and Canadian programs for classification of water and wastewater treatment plant personnel. Included are main characteristics of the programs, educational and experience requirements, and indications of requirement substitutions. (CS)

Water and Sewage Works, 1979

1979-01-01

108

Drinking Water Plant Lecture-Demonstration.  

ERIC Educational Resources Information Center

Describes a simple way to demonstrate the principles involved in a drinking water plant. This demonstration developed for a general public lecture can be used in chemistry and biology courses for an ecological and environmental emphasis. (HM)

Vestling, Martha M.

1977-01-01

109

PERFORMANCE CHARACTERISTICS OF PACKAGE WATER TREATMENT PLANTS  

EPA Science Inventory

This study was undertaken to collect reliable onsite information on the quality of treated water produced by package plants. Six plants in operation year around were selected to be representative of those serving small populations and were monitored to assess their performance. P...

110

A method to determine plant water source using transpired water  

NASA Astrophysics Data System (ADS)

A method to determine the stable isotope ratio of a plant's water source using the plant's transpired water is proposed as an alternative to standard xylem extraction methods. The method consists of periodically sampling transpired waters from shoots or leaves enclosed in sealed, transparent bags which create a saturated environment, preclude further evaporation and allow the progressive mixing of evaporated transpired water and un-evaporated xylem water. The method was applied on trees and shrubs coexisting in a non-irrigated area where stable isotope ratios of local environmental waters are well characterized. The results show Eucalyptus globulus (tree) and Genista monspessulana (shrub) using water sources of different isotopic ratios congruent with groundwater and soil water respectively. In addition, tritium concentrations indicate that pine trees (Pinus sylvestris) switch water source from soil water in the winter to groundwater in the summer. The method proposed is particularly useful in remote or protected areas and in large scale studies related to water management, environmental compliance and surveillance, because it eliminates the need for destructive sampling and greatly reduces costs associated with laboratory extraction of xylem waters from plant tissues for isotopic analyses.

Menchaca, L. B.; Smith, B. M.; Connolly, J.; Conrad, M.; Emmett, B.

2007-04-01

111

Radiolytic decomposition and corrosion of a heavy-water blanket for accelerator driven transmutation Modeling and experimental tests  

NASA Astrophysics Data System (ADS)

The concept of a chemical-engineering complex and its operation stability is described for a radioactive-waste separation and transmutation plant. In the framework of the plant, this chemical complex runs in a closed cycle with a nuclear transmutation reactor driven by a 1 GeV-100 mA class accelerator. Heavy water provides circulation of materials to be transmuted in the reactor blanket and transports the irradiated suspension to and from the chemical-engineering complex for reprocessing and further disposal of transmutation products. Modeling and experimental tests of radiolytic decomposition and corrosion were made in order to evaluate the operation stability of the desired separation and transmutation cycle. Preliminary calculations were made for some methods to suppress gas evolution from water (deuterium) solutions with thorium and transuranium nuclides or from suspensions of their oxides at a pressure of 10 MPa, a temperature of 285°C and radiation doses up to 5×10 7 Gy. The results were checked experimentally. Also the change in size of the suspended particles during irradiation was measured. Additionally, corrosion rates of zirconium alloy tubes were estimated from experiments under the same conditions.

Kulikov, I. A.; Aleksandrov, V. V.; Makarov, V. M.; Volk, V. I.; Vakhrushin, A. Yu; Kazaritsky, V. D.

112

Effects of arbuscular mycorrhizal colonisation on shoot and root decomposition of different plant species and species mixtures  

Microsoft Academic Search

We studied the decomposition of shoot and root tissues of four plant species from central Argentina belonging to contrasting functional types: a deciduous shrub (Acacia caven), a perennial forb (Hyptis mutabilis), an annual forb (Bidens pilosa) and a tussock grass (Jarava pseudoichu). They were grown from seed in a greenhouse in isolation or in 2- or 4-species mixtures, with and

Carlos Urcelay; María Victoria Vaieretti; Marisela Pérez; Sandra Díaz

2011-01-01

113

Water vapor recovery from plant growth chambers  

NASA Technical Reports Server (NTRS)

NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. A design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: (1) dehumidification membrane modules to remove water vapor from the air, and (2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.

Ray, R. J.; Newbold, D. D.; Colton, R. H.; Mccray, S. B.

1991-01-01

114

Flooding and the decomposition of litter of four emergent plant species in a prairie wetland  

Microsoft Academic Search

Changes in mass, N, and P for old and new litter of four emergent plant species (Scolochloa festucacea (Willdl.) Link,Phragmites australis (Cav.) Trin ex Steud.,Typha ×glauca Godr., andScirpus lacustris L. spp.glaucus (Sm.) Hartm.) were studied under two water-level regimes in a 10-cell experimental marsh complex in the Delta Marsh, Manitoba,\\u000a Canada. In the normal regime, water levels were kept at

Arnold G. van der Valk; Judith M. Rhymer; Henry R. Murkin

1991-01-01

115

Performance of small water treatment plants: The case study of Mutshedzi Water Treatment Plant  

Microsoft Academic Search

The performance of small water treatment plants (SWTPs) was evaluated using Mutshedzi WTP as a case study. The majority of SWTPs in South Africa (SA) that supply water to rural villages face problems of cost recovery, water wastages, limited size and semi-skilled labour. The raw and final water quality analyses and their compliance were used to assess the performance of

R. Makungo; J. O. Odiyo; N. Tshidzumba

2011-01-01

116

Water recovery using waste heat from coal fired power plants  

Microsoft Academic Search

The potential to treat non-traditional water sources using power plant waste heat in conjunction with membrane distillation is assessed. Researchers and power plant designers continue to search for ways to use that waste heat from Rankine cycle power plants to recover water thereby reducing water net water consumption. Unfortunately, waste heat from a power plant is of poor quality. Membrane

Stephen W. Webb; Charles W. Morrow; Susan Jeanne Altman; Brian P. Dwyer

2011-01-01

117

4. Water treatment plant, view to NW, berm in foreground ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Water treatment plant, view to NW, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

118

5. Water treatment plant, view to N, berm in foreground ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Water treatment plant, view to N, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

119

14. Water treatment plant interior view of chlorination room. View ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. Water treatment plant interior view of chlorination room. View to N - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

120

6. Water treatment plant, view NE, berm in foreground ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Water treatment plant, view NE, berm in foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

121

8. Water treatment plant, view to SE, berm in foreground ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. Water treatment plant, view to SE, berm in foreground covering settling tank - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

122

7. Water treatment plant, view to E, berm in foreground ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Water treatment plant, view to E, berm in foreground covering settling tank - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

123

10. Water treatment plant, view to S. 1965 addition is ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Water treatment plant, view to S. 1965 addition is in the foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

124

13. Water treatment plant interior view of tanks in control ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. Water treatment plant interior view of tanks in control room. View to SW - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

125

3. Water treatment plant, view to W, detail of door ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Water treatment plant, view to W, detail of door area - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

126

2. Water treatment plant entrance, view to W Fort ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Water treatment plant entrance, view to W - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

127

Changes in bacterial and eukaryotic communities during sewage decomposition in Mississippi river water.  

PubMed

Microbial decay processes are one of the mechanisms whereby sewage contamination is reduced in the environment. This decomposition process involves a highly complex array of bacterial and eukaryotic communities from both sewage and ambient waters. However, relatively little is known about how these communities change due to mixing and subsequent decomposition of the sewage contaminant. We investigated decay of sewage in upper Mississippi River using Illumina sequencing of 16S and 18S rRNA gene hypervariable regions and qPCR for human-associated and general fecal Bacteroidales indicators. Mixtures of primary treated sewage and river water were placed in dialysis bags and incubated in situ under ambient conditions for seven days. We assessed changes in microbial community composition under two treatments in a replicated factorial design: sunlight exposure versus shaded and presence versus absence of native river microbiota. Initial diversity was higher in sewage compared to river water for 16S sequences, but the reverse was observed for 18S sequences. Both treatments significantly shifted community composition for eukaryotes and bacteria (P < 0.05). Data indicated that the presence of native river microbiota, rather than exposure to sunlight, accounted for the majority of variation between treatments for both 16S (R = 0.50; P > 0.001) and 18S (R = 0.91; P = 0.001) communities. A comparison of 16S sequence data and fecal indicator qPCR measurements indicated that the latter was a good predictor of overall bacterial community change over time (rho: 0.804-0.814, P = 0.001). These findings suggest that biotic interactions, such as predation by bacterivorous protozoa, can be critical factors in the decomposition of sewage in freshwater habitats and support the use of Bacteroidales genetic markers as indicators of fecal pollution. PMID:25463929

Korajkic, Asja; Parfrey, Laura Wegener; McMinn, Brian R; Baeza, Yoshiki Vazquez; VanTeuren, Will; Knight, Rob; Shanks, Orin C

2015-02-01

128

Dynamics of microbial communities during decomposition of litter from pioneering plants in initial soil ecosystems  

NASA Astrophysics Data System (ADS)

In initial ecosystems, concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degrader's food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany). Two of this region's dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, as indicated by its N content, its bioavailability for the degradation process and the development of microbial communities in the detritusphere and soil. The degradation of the L. corniculatus litter, which had a low C / N ratio, was fast and showed pronounced changes in the microbial community structure 1-4 weeks after litter addition. The degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred between 4 and 30 weeks after litter addition to the soil. However, for both litter materials a clear indication of the importance of fungi for the degradation process was observed both in terms of fungal abundance and activity (13C incorporation activity)

Esperschütz, J.; Zimmermann, C.; Dümig, A.; Welzl, G.; Buegger, F.; Elmer, M.; Munch, J. C.; Schloter, M.

2013-07-01

129

The Water Circuit of the Plants - Do Plants have Hearts ?  

E-print Network

There is a correspondence between the circulation of blood in all higher animals and the circulation of sap in all higher plants - up to heights h of 140 m - through the xylem and phloem vessels. Plants suck in water from the soil, osmotically through the roothair zone, and subsequently lift it osmotically again, and by capillary suction (via their buds, leaves, and fruits) into their crowns. In between happens a reverse osmosis - the endodermis jump - realized by two layers of subcellular mechanical pumps in the endodermis walls which are powered by ATP, or in addition by two analogous layers of such pumps in the exodermis. The thus established root pressure helps forcing the absorbed ground water upward, through the whole plant, and often out again, in the form of guttation, or exudation.

Wolfgang Kundt; Eva Gruber

2006-03-17

130

Adaptive phenotypic plasticity and plant water use  

Microsoft Academic Search

The emergence of new techniques in plant science, including molecular and phenomic tools, presents a novel opportunitytore-evaluatethewayweexaminethephenotype.Ourincreasingcapacityforphenotypingmeansthatnotonly canweconsiderincreasingnumbersofspeciesorvarieties,butalsothatwecaneffectivelyquantifythephenotypesofthese differentgenotypesunderarangeofenvironmentalconditions.Thephenotypicplasticityofagivengenotype,ortherangeof phenotypes, that can be expressed dependent upon environment becomes something we can feasibly assess. Of particular importance is phenotypic variation that increases fitness or survival - adaptive phenotypic plasticity. Here, we examine the case of adaptive phenotypic plasticity in plant water

Adrienne B. NicotraA; Amy DavidsonA

2010-01-01

131

(Plant growth with limited water)  

SciTech Connect

When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

Not Available

1992-01-01

132

Water relations of riparian plants from warm desert regions  

Microsoft Academic Search

Riparian plants have been classified as “drought avoiders” due to their access to an abundant subsurface water supply. Recent\\u000a water-relations research that tracks water sources of riparian plants using the stable isotopes of water suggests that many\\u000a plants of the riparian zone use ground water rather than stream water, and not all riparian plants are obligate phreatophytes\\u000a (dependent on ground

Stanley D. Smith; Dale A. Devitt; Anna Sala; James R. Cleverly; David E. Busch

1998-01-01

133

Plant Water Uptake in Drying Soils1  

PubMed Central

Over the last decade, investigations on root water uptake have evolved toward a deeper integration of the soil and roots compartment properties, with the goal of improving our understanding of water acquisition from drying soils. This evolution parallels the increasing attention of agronomists to suboptimal crop production environments. Recent results have led to the description of root system architectures that might contribute to deep-water extraction or to water-saving strategies. In addition, the manipulation of root hydraulic properties would provide further opportunities to improve water uptake. However, modeling studies highlight the role of soil hydraulics in the control of water uptake in drying soil and call for integrative soil-plant system approaches. PMID:24515834

Lobet, Guillaume; Couvreur, Valentin; Meunier, Félicien; Javaux, Mathieu; Draye, Xavier

2014-01-01

134

Plant water uptake in drying soils.  

PubMed

Over the last decade, investigations on root water uptake have evolved toward a deeper integration of the soil and roots compartment properties, with the goal of improving our understanding of water acquisition from drying soils. This evolution parallels the increasing attention of agronomists to suboptimal crop production environments. Recent results have led to the description of root system architectures that might contribute to deep-water extraction or to water-saving strategies. In addition, the manipulation of root hydraulic properties would provide further opportunities to improve water uptake. However, modeling studies highlight the role of soil hydraulics in the control of water uptake in drying soil and call for integrative soil-plant system approaches. PMID:24515834

Lobet, Guillaume; Couvreur, Valentin; Meunier, Félicien; Javaux, Mathieu; Draye, Xavier

2014-04-01

135

Effects of water flow regulation on ecosystem functioning in a Mediterranean river network assessed by wood decomposition.  

PubMed

Mediterranean rivers are extensively modified by flow regulation practises along their courses. An important part of the river impoundment in this area is related to the presence of small dams constructed mainly for water abstraction purposes. These projects drastically modified the ecosystem morphology, transforming lotic into lentic reaches and increasing their alternation along the river. Hydro-morphologial differences between these reaches indicate that flow regulation can trigger important changes in the ecosystem functioning. Decomposition of organic matter is an integrative process and this complexity makes it a good indicator of changes in the ecosystem. The aim of this study was to assess the effect caused by flow regulation on ecosystem functioning at the river network scale, using wood decomposition as a functional indicator. We studied the mass loss from wood sticks during three months in different lotic and lentic reaches located along a Mediterranean river basin, in both winter and summer. Additionally, we identified the environmental factors affecting decomposition rates along the river orders. The results revealed differences in decomposition rates between sites in both seasons that were principally related to the differences between stream orders. The rates were mainly related to temperature, nutrient concentrations (NO2(-), NO3(2-)) and water residence time. High-order streams with higher temperature and nutrient concentrations exhibited higher decomposition rates compared with low-order streams. The effect of the flow regulation on the decomposition rates only appeared to be significant in high orders, especially in winter, when the hydrological characteristics of lotic and lentic habitats widely varied. Lotic reaches with lower water residence time exhibited greater decomposition rates compared with lentic reaches probably due to more physical abrasion and differences in the microbial assemblages. Overall, our study revealed that in high orders the reduction of flow caused by flow regulation affects the wood decomposition indicating changes in ecosystem functioning. PMID:25721144

Abril, Meritxell; Muñoz, Isabel; Casas-Ruiz, Joan P; Gómez-Gener, Lluís; Barceló, Milagros; Oliva, Francesc; Menéndez, Margarita

2015-06-01

136

Decomposition behavior of hemicellulose and lignin in the step-change flow rate liquid hot water.  

PubMed

Hemicellulose and lignin are the main factors limiting accessibility of hydrolytic enzymes besides the crystallinity of cellulose. The decomposition behavior of hemicellulose and lignin in the step-change flow rate hot water system was investigated. Xylan removal increased from 64.53% for batch system (solid concentration 4.25% w/v, 18 min, 184°C) to 83.78% at high flow rates of 30 ml/min for 8 min, and then 10 ml/min for 10 min. Most of them (80-90%) were recovered as oligosaccharide. It was hypothesized that the flowing water could enhance the mass transfer to improve the sugars recovery. In addition, the solubilization mechanism of lignin in the liquid hot water was proposed according to the results of Fourier transform-infrared spectroscopy and scanning electron microscopy of the water-insoluble fraction and gas chromatography-mass spectrometry of the water-soluble fraction. It was proposed that lignin in the liquid hot water first migrated out of the cell wall in the form of molten bodies, and then flushed out of the reactor. A small quantity of them was further degraded into monomeric products such as vanillin, syringe aldehyde, coniferyl aldehyde, ferulic acid, and p-hydroxy-cinnamic acid. All of these observations would provide important information for the downstream processing, such as purification and concentration of sugars and the enzymatic digestion of residual solid. PMID:22270547

Zhuang, Xinshu; Yu, Qiang; Wang, Wen; Qi, Wei; Wang, Qiong; Tan, Xuesong; Yuan, Zhenhong

2012-09-01

137

Water Movement in Vascular Plants: A Primer  

E-print Network

The origin of land plants was one of the most important events in evolutionary history of earth in terms of its broad impact on metazoan life and the biotic environment. Because vascular tissues enabled land plants to meet the challenges of terrestrial life, it is important to understand the mechanistic basis of water transport through these tissues from soil to the canopy of trees, in some cases almost 100 meters high. The answers to these questions involve not only the biology of plant vasculature, but also the physical properties of water that enable such transport. Although early researchers proposed the hypothesis of cohesion-tension of water as the likely mechanism for sap ascent, the exact mechanism of transport continues to be a hotly debated topic in the field of plant physiology. This debate continues to be enriched with several sophisticated studies on plants of various morphologies growing in diverse habitats. Although a wealth of evidence has upheld the cohesion-tension theory as being fundamenta...

Sane, Sanjay P

2011-01-01

138

VIEW OF BUILDING 124, THE WATER TREATMENT PLANT, LOOKING NORTHEAST. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF BUILDING 124, THE WATER TREATMENT PLANT, LOOKING NORTHEAST. THE ROCKY FLATS PLANT WATER SUPPLY, TREATMENT, STORAGE, AND DISTRIBUTION SYSTEM HAS OPERATED CONTINUOUSLY SINCE 1953 - Rocky Flats Plant, Water Treatment Plant, West of Third Street, north of Cedar Avenue, Golden, Jefferson County, CO

139

RECYCLING OF WATER IN POULTRY PROCESSING PLANTS  

EPA Science Inventory

Studies were conducted on recycling chiller water in a poultry processing plant. The recycling system must be provided with the capability of removing solids and controlling the microbial population. UV was used to control the microbial population. For this control to be effectiv...

140

WATER REUSE IN A PAPER REPROCESSING PLANT  

EPA Science Inventory

This project was undertaken to determine the feasibility of water reuse in a paper reprocessing plant with the goal being to 'close the loop' or to demonstrate zero discharge technology. Before the project began, Big Chief Roofing Company at Ardmore, OK, was discharging 7.89 1/se...

141

Effects of Water Pollution on Plants  

NSDL National Science Digital Library

This is an inquiry activity that, while based on a local area (the San Francisco Bay), could be adapted to the teacher's/student's local area. Students perform an experiment in which they observe how water pollution is absorbed into plants. The site contains a teacher's guide and printable student worksheet.

142

Plant traits and decomposition: are the relationships for roots comparable to those for leaves?  

PubMed Central

Background and Aims Fine root decomposition is an important determinant of nutrient and carbon cycling in grasslands; however, little is known about the factors controlling root decomposition among species. Our aim was to investigate whether interspecific variation in the potential decomposition rate of fine roots could be accounted for by root chemical and morphological traits, life history and taxonomic affiliation. We also investigated the co-ordinated variation in root and leaf traits and potential decomposition rates. Methods We analysed potential decomposition rates and the chemical and morphological traits of fine roots on 18 Mediterranean herbaceous species grown in controlled conditions. The results were compared with those obtained for leaves in a previous study conducted on similar species. Key Results Differences in the potential decomposition rates of fine roots between species were accounted for by root chemical composition, but not by morphological traits. The root potential decomposition rate varied with taxonomy, but not with life history. Poaceae, with high cellulose concentration and low concentrations of soluble compounds and phosphorus, decomposed more slowly than Asteraceae and Fabaceae. Patterns of root traits, including decomposition rate, mirrored those of leaf traits, resulting in a similar species clustering. Conclusions The highly co-ordinated variation of roots and leaves in terms of traits and potential decomposition rate suggests that changes in the functional composition of communities in response to anthropogenic changes will strongly affect biogeochemical cycles at the ecosystem level. PMID:22143881

Birouste, Marine; Kazakou, Elena; Blanchard, Alain; Roumet, Catherine

2012-01-01

143

An experimental comparison of chemical traits and litter decomposition rates in a diverse range of subarctic bryophyte, lichen and vascular plant species  

Microsoft Academic Search

P1. Climate change in the subarctic is expected to influence vegetation composition, specifically bryophyte and lichen communities, thereby modifying litter decomposition rates and carbon (C) dynamics of these systems with possible feedbacks to climate. 2. In a 2-year experiment, we investigated decomposition rates and chemical traits of 27 bryophytes, 17 lichens and 5 vascular plants in litter beds in subarctic

Simone I. Lang; Johannes H. C. Cornelissen; Thorsten Klahn; Richard S. P. van Logtestijn; Rob Broekman; Wenka Schweikert; Rien Aerts

2009-01-01

144

Influence of water potential on decomposition of soil organic matter in high elevation meadows  

NASA Astrophysics Data System (ADS)

High elevation meadows of the Sierra Nevada, California are defined by the presence of a high water table throughout the growing season. This definition takes into account the natural drawdown of most meadow systems during the summer months to within a few feet of the surface. The cyclic drawdown/recharge of the meadow water table, as well as local hydrologic gradient that exists in most meadow systems (ranging from xeric to hydric) impose important controls on organic matter storage and decomposition in these systems. In this study we incubated soils from the xeric, mesic and hydric regions of a subalpine Sierra Nevada meadow at five different water potentials and measured the CO2 flux at intervals over one year. We found that the cumulative carbon mineralization was greatest at the lowest (0.1 bar) and highest (4 bar) water potentials, across all regions of the meadow, suggesting a microbial response threshold that is reached as the soil dries. Soils from the hydric meadow regions showed the largest response to extreme drying of the soil. These results highlight the importance of soil moisture in regulating soil respiration in these systems and different levels of microbial activity when these soils are wet vs. dry. While normal conditions in these systems keep water potentials low (< 0.2 bar), future drought conditions can potentially increase the level of dryness in the meadows to the point where rapid carbon loss can be expected.

Arnold, C. L.; Ghezzehei, T. A.; Berhe, A.

2013-12-01

145

Decomposition of Dye in Water Solution by Pulsed Power Discharge in a Water Droplet Spray  

Microsoft Academic Search

A method for decomposing dye by spraying water solution of dye into nonequilibrium plasma in gas phase was investigated using a pulsed-corona discharge reactor. The corona reactor consists of a discharge wire and a cylindrical electrode. The water solution of indigo carmine with a concentration of 20 mg\\/L was sprayed into the reactor from a showerhead. The sprayed water solution

Yasushi Minamitani; Satoshi Shoji; Yoshihiro Ohba; Yoshio Higashiyama

2008-01-01

146

Stability of Supported Platinum Sulfuric Acid Decomposition Catalysts for use in Thermochemical Water Splitting Cycles  

SciTech Connect

The activity and stability of several metal oxide supported platinum catalysts were explored for the sulfuric acid decomposition reaction. The acid decomposition reaction is common to several sulfur based thermochemical water splitting cycles. Reactions were carried out using a feed of concentrated liquid sulfuric acid (96 wt%) at atmospheric pressure at temperatures between 800 and 850 °C and a weight hour space velocity of 52 g acid/g catalyst/hr. Reactions were run at these high space velocities such that variations in kinetics were not masked by surplus catalyst. The influence of exposure to reaction conditions was explored for three catalysts; 0.1-0.2 wt% Pt supported on alumina, zirconia and titania. The higher surface area Pt/Al2O3 and Pt/ZrO2 catalysts were found to have the highest activity but deactivated rapidly. A low surface area Pt/TiO2 catalyst was found to have good stability in short term tests, but slowly lost activity for over 200 hours of continuous operation.

Daniel M. Ginosar; Lucia M. Petkovic; Anne W. Glenn; Kyle C. Burch

2007-03-01

147

Succession of Phylogeny and Function During Plant Litter Decomposition (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)  

SciTech Connect

Eoin Brodie of Berkeley Lab on "Succession of phylogeny and function during plant litter decomposition" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

Brodie, Eoin [Berkeley Lab

2013-03-01

148

Understanding Beijing's water challenge: a decomposition analysis of changes in Beijing's water footprint between 1997 and 2007.  

PubMed

Beijing has been experiencing increasing water shortage alongside its astonishing economic growth over the past decades. This study conducts a quasi-dynamic input-output (IO) analysis to investigate changes in Beijing's water footprint (WF) and decompose the effects of contributing factors to the changes during 1997-2007. The analysis distinguishes "internal" and "external" WF to depict connections of Beijing's water use with outside. The results show an increase in Beijing's WF from 4342 million m(3) in 1997 to 5748 million m(3) in 2007. Almost all the increase was attributable to the expansion of the external WF, while the internal WF only changed slightly, indicating a growing dependence of Beijing on external water resources. The decomposition analysis reveals that the technological effect was the principal contributor to offset the WF increase and the structural effect stemmed from the shift of demand toward products of the tertiary industries also contributed to reducing the WF. However, these effects were not sufficient to reverse the expansion of Beijing's WF resulted from the scale effect induced by expansion of final demand and the economic system efficiency effect associated with the growth of trade between Beijing and outside. The study provides insights into Beijing's water challenge and sheds lights on the combating strategies for the future. It is also an endeavor to enhance the policy relevance of the WF studies. PMID:23127171

Zhang, Zhuoying; Shi, Minjun; Yang, Hong

2012-11-20

149

The catalytic decomposition of silver coated cinnamyl alcohol during water exposure and the formation of silver nanoparticles  

NASA Astrophysics Data System (ADS)

Metastable Induced Electron Spectroscopy, Ultraviolet Photoelectron Spectroscopy (He I), X-ray Photoelectron Spectroscopy, and Quadrupole Mass Spectrometry are employed to study the interaction of water with Ag nanoparticles on cinnamyl alcohol films. The films have been prepared on Au(111) substrates by thermal evaporation. The water adsorption does not result in any chemical interaction with the silver nanoparticles at all, but the cinnamyl alcohol changes its chemical structure significantly. While water molecules induce a reduction of the organic groups, the film thickness seems to decrease. Thus, a decomposition of the cinnamyl alcohol films is proposed. Since no effects are observed during water interaction with pure cinnamyl alcohol films at all, a catalytic reaction appears to take place. No decomposition is found for cinnamyl alcohol adsorbed on a closed silver film, indicating that Ag nanoparticles are required for this catalytical decomposition. The MIES and UPS spectra indicate the existence of a closed metallic film directly after silver adsorption on cinnamyl alcohol, while they suggest the presence of silver nanoparticles after the exposure to water. The formation of silver nanoparticles therefore seems to happen concurrently to the catalytic decomposition of cinnamyl alcohol.

Dahle, S.; Höfft, O.; Viöl, W.; Maus-Friedrichs, W.

2014-03-01

150

Upgrading Water Treatment Plants: An Alternative to New Construction  

Microsoft Academic Search

Because of more stringent water quality requirements, many water utilities must reevaluate the operation of plant facilities to determine that optimum water quality is being provided in the most efficient and cost effective manner. Modifying unit processes of surface water filtration plants such as rapid mixing, flocculation, sedimentation, filtration, and process control can improve finished water quality, reduce operating costs,

Robert E. Forbes; Gary L. Nickerson; Herbert E. Hudson Jr.; Edmund G. Wagner

1980-01-01

151

Examining an underappreciated control on lignin decomposition in soils? Effects of reactive manganese species on intact plant cell walls  

NASA Astrophysics Data System (ADS)

Lignin comprises a dominant proportion of carbon fluxes into the soil (representing up to 50% of plant litter and roots). Two lines of evidence suggest that manganese (Mn) acts as a strong controlling factor on the residence time of lignin in soil ecosystems. First, Mn content is highly correlated with litter decomposition in temperate and boreal forest soil ecosystems and, second, microbial agents of lignin degradation have been reported to rely on reactive Mn(III)-complexes to specifically oxidize lignin. However, few attempts have been made to isolate the mechanisms responsible for the apparent Mn-dependence of lignin decomposition in soils. Here we tested the hypothesis that Mn(III)-oxalate complexes may act as a perforating 'pretreatment' for structurally intact plant cell walls. We propose that these diffusible oxidizers are small enough to penetrate and react with non-porous ligno-cellulose in cell walls. This process was investigated by reacting single Zinnia elegans tracheary elements with Mn(III)-oxalate complexes in a continuous flow-through microreactor. The uniformity of cultured tracheary elements allowed us to examine Mn(III)-induced changes in cell wall chemistry and ultrastructure on the micro-scale using fluorescence and electron microscopy as well as synchrotron-based infrared and X-ray spectromicroscopy. Our results show that Mn(III)-complexes substantially oxidize specific lignin components of the cell wall, solubilize decomposition products, severely undermine the cell wall integrity, and cause cell lysis. We conclude that Mn(III)-complexes induce oxidative damage in plant cell walls that renders ligno-cellulose substrates more accessible for microbial lignin- and cellulose-decomposing enzymes. Implications of our results for the rate limiting impact of soil Mn speciation and availability on litter decomposition in forest soils will be discussed.

Keiluweit, M.; Bougoure, J.; Pett-Ridge, J.; Kleber, M.; Nico, P. S.

2011-12-01

152

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA  

E-print Network

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA December 1st to February 28th , 2007........................................................................................................................... 7 Sensor Statistics

Massachusetts at Amherst, University of

153

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA  

E-print Network

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA June 1st to August 31st Prepared........................................................................................................................... 7 Sensor Statistics

Massachusetts at Amherst, University of

154

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA  

E-print Network

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA September 1st to November 30th , 2006........................................................................................................................... 7 Sensor Statistics

Massachusetts at Amherst, University of

155

Hydraulic lift and water use by plants: implications for water balance, performance and plant-plant interactions  

Microsoft Academic Search

During drought periods, sugar maple (Acer saccharum) demonstrates “hydraulic lift”; nocturnal uptake of water by roots from deep soil layers that is released from shallow roots into upper soil layers. Using standard water relations methods and stable hydrogen isotope analysis of both source-water and plant-water, I investigated (1) the magnitude and radial extent of hydraulic lift by mature, relatively open-grown

Todd E. Dawson

1993-01-01

156

Suppressing NOM access to controlled porous TiO2 particles enhances the decomposition of target water contaminants  

EPA Science Inventory

Suppressing access of natural organic matter (NOM) to TiO2 is a key to the successful photocatalytic decomposition of a target contaminant in water. This study first demonstrates simply controlling the porous structure of TiO2 can significantly improve the selective oxidation....

157

Unique automatic water treatment plant at Silverdale Colliery  

Microsoft Academic Search

A continuously operating semi-automatic water treatment plant for treating 400 gallons per minute of acid mine drainage is described. The plant produces a clear water effluent which complies with the standards for disposal to the river system; some of the cleaned water is used by the colliery. Most of the plant is automatically controlled, but filtration is done only on

Whitworth

1978-01-01

158

CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organic matter...

159

Decomposition of duckweed (Lemna gibba) under axenic and microbial [-2pt] conditions: flux of nutrients between litter water and sediment, the impact of leaching and microbial degradation  

Microsoft Academic Search

The decomposition of axenic Lemna gibba has been studied over a 200 day period under laboratory conditions in the presence and absence of wastewater micro-organisms. The residual mass of plant litter in the decomposition vessels decreased three times more rapidly under biotic than abiotic conditions. The organic matter in the duckweed litter lost about half its weight within 67.9 days

Sándor Szabó; Mihály Braun; Péter Nagy; Sándor Balázsy; Otto Reisinger

2000-01-01

160

Estimating winter wheat plant water content using red edge parameters  

Microsoft Academic Search

Remote sensing of plant water content is difficult because the absorption band sensitive to foliar liquid water is also sensitive to the atmospheric vapour. A method using non-water-absorption spectral parameters to evaluate plant water content (PWC) would be valuable. In our experiment, canopy spectra of 48 winter wheat treatments with different varieties, different fertilization and irrigation levels were measured by

Liangyun Liu; Jihua Wang; Wenjiang Huang; Chunjiang Zhao; Bing Zhang; Qingxi Tong

2004-01-01

161

Performance of small water treatment plants: The case study of Mutshedzi Water Treatment Plant  

NASA Astrophysics Data System (ADS)

The performance of small water treatment plants (SWTPs) was evaluated using Mutshedzi WTP as a case study. The majority of SWTPs in South Africa (SA) that supply water to rural villages face problems of cost recovery, water wastages, limited size and semi-skilled labour. The raw and final water quality analyses and their compliance were used to assess the performance of the Mutshedzi WTP. Electrical conductivity (EC), p? and turbidity were measured in the field using a portable multimeter and a turbidity meter respectively. Atomic Absorption Spectrometry and Ion Chromatography were used to analyse metals and non-metals respectively. The results were compared with the Department of Water Affairs (DWA) guidelines for domestic use. The turbidity levels partially exceeded the recommended guidelines for domestic water use of 1 NTU. The concentrations of chemical parameters in final water were within the DWA guidelines for domestic water use except for fluoride, which exceeded the maximum allowable guideline of 1.5 mg/L in August 2009. Mutshedzi WTP had computed compliance for raw and final water analyses ranging from 79% to 93% and 86% to 93% throughout the sampling period, respectively. The results from earlier studies showed that the microbiological quality of final water in Mutshedzi WTP complied with the recommended guidelines, eliminating the slight chance of adverse aesthetic effects and infectious disease transmission associated with the turbidity values between 1 and 5 NTU. The study concluded that Mutshedzi WTP, though moving towards compliance, is still not producing adequate quality of water. Other studies also indicated that the quantity of water produced from Mutshedzi WTP was inadequate. The findings of the study indicate that lack of monitoring of quantity of water supplied to each village, dosage of treatment chemicals, the treatment capacity of the WTP and monitoring the quality of water treated are some of the factors that limit the performance of Mutshedzi WTP. These have been confirmed in literature to be widespread in similar WTPs in SA. It is recommended that water meters be provided and the community be advised to subsidise the cost of water supply. The study recommended that the treatments of turbidity and fluoride should form critical functions of the plant to ensure that final water for domestic use is always safe from any harmful substances or disease causing pathogens. The study concluded that the WTP only needs minor improvement to boost its efficiency with regard to the treatment of raw water. This will also ensure that the plant achieves 100% compliance for final water.

Makungo, R.; Odiyo, J. O.; Tshidzumba, N.

162

Problems of Terminology in the Teaching of Plant Water Relations  

ERIC Educational Resources Information Center

Recommends use by teachers of new terminology regarding plant water relations. Includes definitions and Greek symbols for the following terms: water potential, water potential of cell, osmotic potential, matric potential, and pressure potential. (CS)

Bradbeer, Philip A.; And Others

1976-01-01

163

Layerwise decomposition of water dynamics in reverse micelles: A simulation study of two-dimensional infrared spectrum  

NASA Astrophysics Data System (ADS)

We present computer simulation study of two-dimensional infrared spectroscopy (2D-IR) of water confined in reverse micelles (RMs) of various sizes. The present study is motivated by the need to understand the altered dynamics of confined water by performing layerwise decomposition of water, with an aim to quantify the relative contributions of different layers water molecules to the calculated 2D-IR spectrum. The 0-1 transition spectra clearly show substantial elongation, due to inhomogeneous broadening and incomplete spectral diffusion, along the diagonal in the surface water layer of different sized RMs. Fitting of the frequency fluctuation correlation functions reveal that the motion of the surface water molecules is sub-diffusive and indicate the constrained nature of their dynamics. This is further supported by two peak nature of the angular analogue of van Hove correlation function. With increasing system size, the water molecules become more diffusive in nature and spectral diffusion almost completes in the central layer of the larger size RMs. Comparisons between experiments and simulations establish the correspondence between the spectral decomposition available in experiments with the spatial decomposition available in simulations. Simulations also allow a quantitative exploration of the relative role of water, sodium ions, and sulfonate head groups in vibrational dephasing. Interestingly, the negative cross correlation between force on oxygen and hydrogen of O-H bond in bulk water significantly decreases in the surface layer of each RM. This negative cross correlation gradually increases in the central water pool with increasing RMs size and this is found to be partly responsible for the faster relaxation rate of water in the central pool.

Biswas, Rajib; Furtado, Jonathan; Bagchi, Biman

2013-10-01

164

Layerwise decomposition of water dynamics in reverse micelles: a simulation study of two-dimensional infrared spectrum.  

PubMed

We present computer simulation study of two-dimensional infrared spectroscopy (2D-IR) of water confined in reverse micelles (RMs) of various sizes. The present study is motivated by the need to understand the altered dynamics of confined water by performing layerwise decomposition of water, with an aim to quantify the relative contributions of different layers water molecules to the calculated 2D-IR spectrum. The 0-1 transition spectra clearly show substantial elongation, due to inhomogeneous broadening and incomplete spectral diffusion, along the diagonal in the surface water layer of different sized RMs. Fitting of the frequency fluctuation correlation functions reveal that the motion of the surface water molecules is sub-diffusive and indicate the constrained nature of their dynamics. This is further supported by two peak nature of the angular analogue of van Hove correlation function. With increasing system size, the water molecules become more diffusive in nature and spectral diffusion almost completes in the central layer of the larger size RMs. Comparisons between experiments and simulations establish the correspondence between the spectral decomposition available in experiments with the spatial decomposition available in simulations. Simulations also allow a quantitative exploration of the relative role of water, sodium ions, and sulfonate head groups in vibrational dephasing. Interestingly, the negative cross correlation between force on oxygen and hydrogen of O-H bond in bulk water significantly decreases in the surface layer of each RM. This negative cross correlation gradually increases in the central water pool with increasing RMs size and this is found to be partly responsible for the faster relaxation rate of water in the central pool. PMID:24116645

Biswas, Rajib; Furtado, Jonathan; Bagchi, Biman

2013-10-14

165

WSU-TFREC Orchard Calculator: Estimating Water Use by Plants  

NSDL National Science Digital Library

The Washington State University Tree Fruit Research and Extension Center provides a calculator for estimating water use by plants or pET (potential evapotranspiration). Water use varies widely from plant to plant, so estimates are usually first derived for a single situation, such as grass, and then adapted for other plants. The calculator uses the Penman method to estimate daily pET in inches of water. It requires average daily values of four measurements: sunlight, wind, temperature, and humidity.

1996-05-29

166

USE of mine pool water for power plant cooling  

Microsoft Academic Search

Water and energy production issues intersect in numerous ways. Water is produced along with oil and gas, water runs off of or accumulates in coal mines, and water is needed to operate steam electric power plants and hydropower generating facilities. However, water and energy are often not in the proper balance. For example, even if water is available in sufficient

J. A. Veil; J. M. Kupar; M. G. Puder

2006-01-01

167

DECOMPOSITION OF TRIHALOACETIC ACIDS AND FORMATION OF THE CORRESPONDING TRIHALOMETHANES IN DRINKING WATER. (R826834)  

EPA Science Inventory

The decomposition of trihaloacetic acids [bromodichloroacetic acid (BDCAA), dibromochloroacetic acid (DBCAA), tribromoacetic acid (TBAA)], and the formation of the corresponding trihalomethanes [bromodichloromethane (BDCM), dibromochloromethane (DBCM), tribromomethane (TBM)] w...

168

BARIUM AND RADIUM IN WATER TREATMENT PLANT WASTES  

EPA Science Inventory

Water treatment plants at nine locations (10 plants) in Illinois and Iowa were studied to determine the characteristics and disposal practices for the sludge, brine, and backwash water containing radium (Ra) and/or barium (Ba). The treatment processes in these ten plants include ...

169

11. Water treatment plant interior view of pipes, stairs, and ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Water treatment plant interior view of pipes, stairs, and pump in pump room. View to SW - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

170

12. Water treatment plant interior view of pipes and pump ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Water treatment plant interior view of pipes and pump in heater room. View to W - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

171

Nonadditive effects of litter mixtures on decomposition and correlation with initial litter N and P concentrations in grassland plant species of northern China  

Microsoft Academic Search

We studied the occurrence of nonadditive effects of litter mixtures on the decomposition (the deviation of decomposition rate\\u000a of litter mixtures from the expected values based on the arithmetic means of individual litter types) of litters from three\\u000a plant species (i.e., Stipa krylovii Roshev., Artemisia frigida Willd., and Allium bidentatum Fisch. ex Prokh. & Ikonn.-Gal.) endemic to the grassland ecosystems

Ping Liu; Osbert J. Sun; Jianhui Huang; Linghao Li; Xingguo Han

2007-01-01

172

Plant species and nutritional-mediated control over rhizodeposition and root decomposition  

Microsoft Academic Search

This study focuses on the influence of nitrogen (N) availability and species on rhizodeposition and on decomposition of rhizodeposits, roots and soil organic matter. Four perennial grass species were studied that are characteristic of grassland habitats that differ in nutrient availability. These perennial grass species, Holcus lanatus L., Festuca rubra L., Anthoxanthum odoratum L. and Festuca ovina L., were homogeneously

Tanja A. J. Van der Krift; Peter J. Kuikman; Frans Möller; Frank Berendse

2001-01-01

173

Decomposition of litter produced under elevated CO 2 : Dependence on plant species and nutrient supply  

Microsoft Academic Search

We investigated the effect of CO2 concentration and soilnutrient availability during growth on the subsequent decomposition andnitrogen (N) release from litter of four annual grasses that differ inresource requirements and native habitat. Vulpia microstachys isa native grass found on California serpentine soils, whereas Avenafatua, Bromus hordaceus, and Lolium multiflorum areintroduced grasses restricted to more fertile sandstone soils (Hobbs & Mooney

VALERIE M. FRANCK; BRUCE A. HUNGATE; F. STUART CHAPIN; CHRISTOPHER B. FIELD

1997-01-01

174

Decomposition of root mixtures from high arctic plants: a microcosm study  

Microsoft Academic Search

Fine roots (<1 mm dia.) of Dryas octopetala L., Carex rupestris All., Saxifraga oppositifolia L. and Salix polaris Wahlenb. were decomposed as single species, and in mixtures with fine roots of D. octopetala, under laboratory conditions. Decomposition was measured as carbon dioxide release and mass loss over 556 d at 6°C. There was no relationship between cumulative CO2 release and

C. H. Robinson; J. B. Kirkham; R. Littlewood

1999-01-01

175

Soil water availability for plants as quantified by conventional available water, least limiting water range and integral water capacity  

Microsoft Academic Search

There are different approaches to define the soil available water (SAW) for plants. The objectives of this study are to evaluate\\u000a the SAW values of 12 arable soils from Hamadan province (western Iran) calculated by plant available water (PAW), least limiting\\u000a water range (LLWR) and integral water capacity (IWC) approaches and to explore their relations with Dexter’s index of soil

Hossein Asgarzadeh; Mohammad Reza Mosaddeghi; Ali Akbar Mahboubi; Akram Nosrati; Anthony Roger Dexter

2010-01-01

176

Moisture drives surface decomposition in thawing tundra  

NASA Astrophysics Data System (ADS)

Permafrost thaw can affect decomposition rates by changing environmental conditions and litter quality. As permafrost thaws, soils warm and thermokarst (ground subsidence) features form, causing some areas to become wetter while other areas become drier. We used a common substrate to measure how permafrost thaw affects decomposition rates in the surface soil in a natural permafrost thaw gradient and a warming experiment in Healy, Alaska. Permafrost thaw also changes plant community composition. We decomposed 12 plant litters in a common garden to test how changing plant litter inputs would affect decomposition. We combined species' tissue-specific decomposition rates with species and tissue-level estimates of aboveground net primary productivity to calculate community-weighted decomposition constants at both the thaw gradient and warming experiment. Moisture, specifically growing season precipitation and water table depth, was the most significant driver of decomposition. At the gradient, an increase in growing season precipitation from 200 to 300 mm increased mass loss of the common substrate by 100%. At the warming experiment, a decrease in the depth to the water table from 30 to 15 cm increased mass loss by 100%. At the gradient, community-weighted decomposition was 21% faster in extensive than in minimal thaw, but was similar when moss production was included. Overall, the effect of climate change and permafrost thaw on surface soil decomposition are driven more by precipitation and soil environment than by changes to plant communities. Increasing soil moisture is thereby another mechanism by which permafrost thaw can become a positive feedback to climate change.

Hicks Pries, Caitlin E.; Schuur, E. A. G.; Vogel, Jason G.; Natali, Susan M.

2013-07-01

177

Costs and water quality effects of wastewater treatment plant centralization  

Microsoft Academic Search

The costs and water quality impacts of two regional configurations of municipal wastewater treatment plants in Northeastern Illinois are compared. In one configuration, several small treatment plants are consolidated into a smaller number of regional facilities. In the other, the smaller plants continue to operate. Costs for modifying the plants to obtain various levels of pollutant removal are estimated using

C. M. Macal; B. J. Broomfield

1980-01-01

178

Electricity and potable water from a solar tower power plant  

Microsoft Academic Search

The cogeneration of electricity and potable water utilising solar energy is studied, assuming solar tower power plants with the open volumetric PHOEBUS receiver. The results for alternative plant configurations show that the water production cost is about the same or even lower than the cost of water produced by conventionally fired systems. Furthermore, the integration offers a reduction of CO2-emissions

Jürgen Rheinländer; Frank Lippke

1998-01-01

179

Texas refiner starts up new waste water treatment plant  

Microsoft Academic Search

Chevron Corp. has started up a new waste water treatment plant at its Port Arthur, Tex., refinery. The new facility has an hydraulic capacity of 10,000 gpm and will treat process waste water, cooling tower blowdown, and contaminated storm water. The plant includes: A process unit for removing free and emulsified oil; and equalization facility; a biological system for organics

N. Al-Tell; R. Lueders

1994-01-01

180

27. CUSHMAN POWER PLANT NO. 1, WATER CURVE SPILLWAY ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. CUSHMAN POWER PLANT NO. 1, WATER CURVE - SPILLWAY OVERFLOW CHANNEL. July 1928. Reference BT-109 - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA

181

Decomposition of atrazine traces in water by combination of non-thermal electrical discharge and adsorption on nanofiber membrane.  

PubMed

In recent decades, several types of persistent substances are detected in the aquatic environment at very low concentrations. Unfortunately, conventional water treatment processes are not able to remove these micropollutants. As such, advanced treatment methods are required to meet both current and anticipated maximally allowed concentrations. Plasma discharge in contact with water is a promising new technology, since it produces a wide spectrum of oxidizing species. In this study, a new type of reactor is tested, in which decomposition by atmospheric pulsed direct barrier discharge (pDBD) plasma is combined with micropollutant adsorption on a nanofiber polyamide membrane. Atrazine is chosen as model micropollutant with an initial concentration of 30 ?g/L. While the H2O2 and O3 production in the reactor is not influenced by the presence of the membrane, there is a significant increase in atrazine decomposition when the membrane is added. With membrane, 85% atrazine removal can be obtained in comparison to only 61% removal without membrane, at the same experimental parameters. The by-products of atrazine decomposition identified by HPLC-MS are deethylatrazine and ammelide. Formation of these by-products is more pronounced when the membrane is added. These results indicate the synergetic effect of plasma discharge and pollutant adsorption, which is attractive for future applications of water treatment. PMID:25482844

Vanraes, Patrick; Willems, Gert; Daels, Nele; Van Hulle, Stijn W H; De Clerck, Karen; Surmont, Pieter; Lynen, Frederic; Vandamme, Jeroen; Van Durme, Jim; Nikiforov, Anton; Leys, Christophe

2014-11-20

182

Microbial functional diversity associated with plant litter decomposition along a climatic gradient.  

PubMed

Predicted changes in climate associated with increased greenhouse gas emissions can cause increases in global mean temperature and changes in precipitation regimes. These changes may affect key soil processes, e.g., microbial CO(2) evolution and biomass, mineralization rates, primary productivity, biodiversity, and litter decomposition, which play an important role in carbon and nutrient cycling in terrestrial ecosystems. Our study examined the changes in litter microbial communities and decomposition along a climatic gradient, ranging from arid desert to humid Mediterranean regions in Israel. Wheat straw litter bags were placed in arid, semi-arid, Mediterranean, and humid Mediterranean sites. Samples were collected seasonally over a 2-year period in order to evaluate mass loss, litter moisture, C/N ratio, bacterial colony-forming units (CFUs), microbial CO(2) evolution and biomass, microbial functional diversity, and catabolic profile. Decomposition rate was the highest during the first year of the study at the Mediterranean and arid sites. Community-level physiological profile and microbial biomass were the highest in summer, while bacterial CFUs were the highest in winter. Microbial functional diversity was found to be highest at the humid Mediterranean site, whereas substrate utilization increased at the arid site. Our results support the assumption that climatic factors control litter degradation and regulate microbial activity. PMID:22430507

Sherman, Chen; Steinberger, Yosef

2012-08-01

183

Outdoor Water Use Conservation through Native Plants Shapiro, Chan, Carson, Tayag Outdoor Water Use Conservation through Native Plants  

E-print Network

for regular turfgrass and buffalo grass (developed by UC Davis as a water efficient alternative to turfgrassOutdoor Water Use Conservation through Native Plants Shapiro, Chan, Carson, Tayag Outdoor Water Use, the front lawn is one of the greatest consumers of outdoor water use. Because of population growth, water

Pasternack, Gregory B.

184

Mass transfer in fuel cells. [electron microscopy of components, thermal decomposition of Teflon, water transport, and surface tension of KOH solutions  

NASA Technical Reports Server (NTRS)

Results of experiments on electron microscopy of fuel cell components, thermal decomposition of Teflon by thermogravimetry, surface area and pore size distribution measurements, water transport in fuel cells, and surface tension of KOH solutions are described.

Walker, R. D., Jr.

1973-01-01

185

Carbon Assimilation Pathways, Water Relationships and Plant Ecology.  

ERIC Educational Resources Information Center

Discusses between-species variation in adaptation of the photosynthetic mechanism to cope with wide fluctuations of environmental water regime. Describes models for water conservation in plants and the role of photorespiration in the evolution of the different pathways. (CW)

Etherington, John R.

1988-01-01

186

A new conceptual model on the fate and controls of fresh and pyrolized plant litter decomposition  

Technology Transfer Automated Retrieval System (TEKTRAN)

The leaching of dissolved organic matter (DOM) from fresh and pyrolyzed aboveground plant inputs to the soil is a major pathway by which decomposing aboveground plant material contributes to soil organic matter formation. Understanding how aboveground plant input chemical traits control the partiti...

187

MYCORRHIZAL MEDIATION OF PLANT N ACQUISITION AND RESIDUE DECOMPOSITION: IMPACT OF MINERAL N INPUTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Arbuscular mycorrhizal (AM) fungi are ubiquitous plant-fungus mutualists in terrestrial ecosystems and play important roles in plant resource capture and nutrient cycling. In this study, we examined how mineral N additions affected mycorrhizal mediation of plant N acquisition and residue decompositi...

188

Urban Water-Quality Management Rain Garden Plants  

E-print Network

A rain garden is a landscaped area specially designed to collect rainfall and storm-water runoff. The plants and soil in the rain garden clean pollutants from the water as it seeps into the ground and evaporates back into the atmosphere. For a rain garden to work, plants must be selected, installed, and maintained properly. Plant Selection • ?Choose plants tolerant of both occasional flooding as well as dry periods. • ?Choose noninvasive plants that are adapted to the local environment. • ?Choose a mixture of species. A good rule of thumb is one plant species for every 10 to 20 square feet. For example – a 140-square-foot garden would have 7 to 14 different plant species. • ?Choose plants for vertical layering – a mix of tall-, medium-, and low-growing species. Plant Installation • ?Install plants in their proper moisture zones (see Fig. 1). • ?Plant shrubs and perennials in groups of three to five of the same species. Trees can be planted in groups or individually. • ?Plant taller and larger plants in the center or at one end of the garden, depending on the views. • ?Plant shorter plants where they can be seen easily, around the garden edges, in front of larger plants, or underneath taller

Mike Andruczyk; Extension Agent; Lynnette Swanson

189

Pt/TiO2 (Rutile) Catalysts for Sulfuric Acid Decomposition in Sulfur-Based Thermochemical Water-Splitting Cycles  

SciTech Connect

Thermochemical cycles consist of a series of chemical reactions to produce hydrogen from water at lower temperatures than by direct thermal decomposition. All the sulfur-based cycles for water splitting employ the sulfuric acid decomposition reaction. This work reports the studies performed on platinum supported on titania (rutile) catalysts to investigate the causes of catalyst deactivation under sulfuric acid decomposition reaction conditions. Samples of 1 wt% Pt/TiO2 (rutile) catalysts were submitted to flowing concentrated sulfuric acid at 1123 K and atmospheric pressure for different times on stream (TOS) between 0 and 548 h. Post-operation analyses of the spent catalyst samples showed that Pt oxidation and sintering occurred under reaction conditions and some Pt was lost by volatilization. Pt loss rate was higher at initial times but total loss appeared to be independent of the gaseous environment. Catalyst activity showed an initial decrease that lasted for about 66 h, followed by a slight recovery of activity between 66 and 102 h TOS, and a period of slower deactivation after 102 h TOS. Catalyst sulfation did not seem to be detrimental to catalyst activity and the activity profile suggested that a complex dynamical situation involving platinum sintering, volatilization, and oxidation, along with TiO2 morphological changes affected catalyst activity in a non-monotonic way.

L. M. Petkovic; D. M. Ginosar; H. W. Rollins; K. C. Burch; P. J. Pinhero; H. H. Farrell

2008-04-01

190

Prediction of the maximum temperature for life based on the stability of metabolites to decomposition in water.  

PubMed

The components of life must survive in a cell long enough to perform their function in that cell. Because the rate of attack by water increases with temperature, we can, in principle, predict a maximum temperature above which an active terrestrial metabolism cannot function by analysis of the decomposition rates of the components of life, and comparison of those rates with the metabolites' minimum metabolic half-lives. The present study is a first step in this direction, providing an analytical framework and method, and analyzing the stability of 63 small molecule metabolites based on literature data. Assuming that attack by water follows a first order rate equation, we extracted decomposition rate constants from literature data and estimated their statistical reliability. The resulting rate equations were then used to give a measure of confidence in the half-life of the metabolite concerned at different temperatures. There is little reliable data on metabolite decomposition or hydrolysis rates in the literature, the data is mostly confined to a small number of classes of chemicals, and the data available are sometimes mutually contradictory because of varying reaction conditions. However, a preliminary analysis suggests that terrestrial biochemistry is limited to environments below ~150-180 °C. We comment briefly on why pressure is likely to have a small effect on this. PMID:25821932

Bains, William; Xiao, Yao; Yu, Changyong

2015-01-01

191

Estimating winter wheat plant water content using red edge width  

Microsoft Academic Search

Remote sensing of vegetation liquid water has important application in agriculture and forestry. The spectral index or features of water absorption in NIR and SWIR have been found useful for the detection of plant water content (PWC). It is unfortunately that the foliar liquid water absorption is superposed by the atmospheric vapor absorption, and it is very difficult to distinguish

Liangyun Liu; Chunjiang Zhao; Wenjiang Huang; Jihua Wang

2003-01-01

192

AQUATIC PLANTS FOR BIOREMEDIATION OF WASTE WATER  

Microsoft Academic Search

The ability of aquatic plants to accumulate heavy metals was examined in Bahr in El Bakar drain as one of the first sized drains in Egypt heavily polluted with heavy metals. Metal enrichment was found to be dependent on the plant species and metal type. The most efficient plant species in accumulating heavy metals were Eichhornia crassipes (floating plant), Ceratophyllum

Assia A. El Falaky; S. A. Aboulroos; A. A. Saoud; M. A. Ali

193

A Class-Information-Based Penalized Matrix Decomposition for Identifying Plants Core Genes Responding to Abiotic Stresses  

PubMed Central

In terms of making genes expression data more interpretable and comprehensible, there exists a significant superiority on sparse methods. Many sparse methods, such as penalized matrix decomposition (PMD) and sparse principal component analysis (SPCA), have been applied to extract plants core genes. Supervised algorithms, especially the support vector machine-recursive feature elimination (SVM-RFE) method, always have good performance in gene selection. In this paper, we draw into class information via the total scatter matrix and put forward a class-information-based penalized matrix decomposition (CIPMD) method to improve the gene identification performance of PMD-based method. Firstly, the total scatter matrix is obtained based on different samples of the gene expression data. Secondly, a new data matrix is constructed by decomposing the total scatter matrix. Thirdly, the new data matrix is decomposed by PMD to obtain the sparse eigensamples. Finally, the core genes are identified according to the nonzero entries in eigensamples. The results on simulation data show that CIPMD method can reach higher identification accuracies than the conventional gene identification methods. Moreover, the results on real gene expression data demonstrate that CIPMD method can identify more core genes closely related to the abiotic stresses than the other methods. PMID:25180509

Liu, Jin-Xing; Liu, Jian; Gao, Ying-Lian; Mi, Jian-Xun; Ma, Chun-Xia; Wang, Dong

2014-01-01

194

Simulation of Water Transport in the Soil-Plant - System.  

NASA Astrophysics Data System (ADS)

The objective of this dissertation is to develop a mechanistic model of water transport in the soil-plant -atmosphere system that describes the plant's physical expression of water stress to study the effects of environmental factors, and plant hydraulic and physical properties on plant water transport. The model includes soil moisture uptake, soil heat and water transfer, evapotranspiration, and energy partitioning in the canopy and at the soil surface. The model inputs are: daily weather data (air temperature, dew point temperature, wind speed, and solar radiation); initial soil moisture and temperature profiles; plant characteristics; root density; and soil hydraulic properties. The model user may select from a number of outputs. Principal outputs include: leaf resistance, leaf temperature, soil moisture profile and evapotranspiration rate. The model describes a feedback mechanism by which transpiration controls leaf water potential, leaf water potential influences leaf resistance, and leaf resistance which, in turn, controls transpiration. The simulation runs represented the energy partitioning in the canopy and at the soil surface, and the diurnal variation of temperatures and vapor pressures of the leaf, the canopy air, and the soil surface. The relationships of leaf water potential to soil water potential, leaf resistance and transpiration were also presented. In addition, results show that root water extraction is related to the root length density profile and the soil moisture profile. The model mechanistically describes the water transport in the soil-plant-atmosphere system. The results of model validation indicated that the model is capable of simulating plant water transport under natural conditions with reasonable accuracy. Results show that the model simulates the basic features of the system including feedback processes. The sensitivity studies show that the model may be used to study plant water response to environmental factors and plant properties. The model is also useful for estimating evapotranspiration and the soil moisture profile and may provide information for irrigation and soil water management. (Abstract shortened with permission of author.).

Guo, Yimei

1992-01-01

195

BENEFICIAL DISPOSAL OF WATER PURIFICATION PLANT SLUDGES IN WASTEWATER TREATMENT  

EPA Science Inventory

This report discusses the advantages and disadvantages of the disposal of waste alum sludge from a water treatment plant to a municipal wastewater treatment plant and is submitted in fulfillment of Grant No. 803336-01 by Novato Sanitary District and North Marin County Water Distr...

196

Optimization of Water Consumption in Second Generation Bioethanol Plants  

E-print Network

1 Optimization of Water Consumption in Second Generation Bioethanol Plants Mariano Martína optimization of second generation bioethanol production plants from lignocellulosic switchgrass when using of these resources have focused on energy sources like crude oil, carbon and natural gas1 . Water has been overlooked

Grossmann, Ignacio E.

197

The impact of uranium mine contamination of soils on plant litter decomposition.  

PubMed

As part of a tier 3 risk assessment performed for a uranium mining area, the ability of soils with different degrees of metal contamination to degrade organic matter was assessed using litter bags filled with leaves of Quercus robur, Pinus pinaster, Salix atrocinerea, or a mixture of the three species. Litter bags were exposed at different sites within the mine area and at a reference area for 3, 6, 9, and 12 months. Biomass loss, nitrogen (N), phosphorus (P), carbon (C) and total fatty acid, total phenolic, and ergosterol contents were assessed for each litter bag retrieved from the field. The decomposition of litter at each site seemed to be governed by a complex interaction of many different factors. After 12 months of exposure, leaves from the most contaminated sites were distinguishable from those from the reference site. In the reference site, the greatest percentages of biomass loss were attained by Q. robur and P. pinaster leaves. These species displayed the second highest and the lowest C-to-N ratios, respectively. In addition, the high P content of the litter from these two species may have favored microbial colonization. The results suggest that the decomposition of P. pinaster and Q. robur leaves may have been favored at the reference site by the high abundance of both species at this site and the subsequent adaptation of the microbial community to their litter. Our study shows that different species of leaf litter should be used to discriminate between contaminated sites with different levels of contamination. PMID:24823679

Freitas, Ana C; Rodrigues, Dina; Rocha-Santos, Teresa A P; Gonçalves, Fernando; Duarte, Armando C; Pereira, Ruth

2014-11-01

198

Air-cooled condensers eliminate plant water use  

SciTech Connect

River or ocean water has been the mainstay for condensing turbine exhaust steam since the first steam turbine began generating electricity. A primary challenge facing today's plant developers, especially in drought-prone regions, is incorporating processes that reduce plant water use and consumption. One solution is to shed the conventional mindset that once-through cooling is the only option and adopt dry cooling technologies that reduce plant water use from a flood to a few sips. A case study at the Astoria Energy plant, New York City is described. 14 figs.

Wurtz, W.; Peltier, R. [SPX Cooling Technologies Inc. (United States)

2008-09-15

199

Foothills: A State-of-the-Art Water Treatment Plant  

Microsoft Academic Search

After three years of operation, the showcase Foothills water treatment plant, serving the base needs of the Denver, Colo., metropolitan area, has been performing at, or above, expectations. Taking hydraulic advantage of its location above the city, the plant's pumping costs are minimal and the plant's hydro turbine generates enough power to operate the facilities and sell excess electricity. A

Robert K. Weir; Robert L. Chapman

1987-01-01

200

INTEGRATED STEEL PLANT POLLUTION STUDY FOR TOTAL RECYCLE OF WATER  

EPA Science Inventory

The report gives results of an engineering study of five integrated U.S. steel plants to determine how each might ultimately achieve total recycle of water. The plants represent a broad cross section of plant-specific factors (e.g., size, age, location, and available space) that ...

201

Simplifying design of water treatment plants for developing countries  

Microsoft Academic Search

Water treatment plants in developing countries should be low in first cost and easy and economical to operate. Maximum use of gravity and hydraulic energy in the treatment process and use of Jabor instead of equipment in plant operation result in the most effective and economical treatment plant.

E. Glenn Wagner

1983-01-01

202

Contactless Water Status Measurements on Plants at 35 GHz  

NASA Astrophysics Data System (ADS)

We demonstrate a method for non-destructive and contactless measurements of the water content of plants, e.g. agricultural crops. The measurement is based on the absorption of microwave radiation at 35 GHz inside the plant and additionally takes scattering on the surface of the plant into account.

Gente, R.; Rehn, A.; Koch, M.

2015-03-01

203

Energy from fresh and brackish water aquatic plants  

Microsoft Academic Search

Aquatic plants can achieve relatively high biomass productivities when compared to terrestrial plants because they need not be water-stressed and can be optimally supplied with nutrients. Based on literature reports, productivities in southern US regions of about 40 to 60 t\\/ha-yr (dry weight basis) can be predicted for green algae or marsh plants and about 80 t\\/ha-yr for water hyacinth.

1981-01-01

204

Decomposition and nutrient liberation rates of plant material in the Parana medio River (Argentina)  

Microsoft Academic Search

The degradation of plant material was studied in order to obtain degradation coefficients and nutrient release kinetics of the vegetation that will be submerged during the filling of the future Parana Medio man-made lake. A group of 13 plant species representative of the whole vegetation of the area were chosen.

M. Leguizamon; J. Hammerly; M. A. Maine; N. Sufie; M. J. Pizarro

1992-01-01

205

Plant experience with temporary reverse osmosis makeup water systems  

SciTech Connect

Pacific Gas and Electric (PG and E) Company's Diablo Canyon Power Plant (DCPP), which is located on California's central coast, has access to three sources of raw water: creek water, well water, and seawater. Creek and well water are DCPP's primary sources of raw water; however, because their supply is limited, these sources are supplemented with seawater. The purpose of this paper is to discuss the temporary, rental, reverse osmosis systems used by PG and E to process DCPP's raw water into water suitable for plant makeup. This paper addresses the following issues: the selection of reverse osmosis over alternative water processing technologies; the decision to use vendor-operated temporary, rental, reverse osmosis equipment versus permanent PG and E-owned and -operated equipment; the performance of DCPP's rental reverse osmosis systems; and, the lessons learned from DCPP's reverse osmosis system rental experience that might be useful to other plants considering renting similar equipment.

Polidoroff, C.

1986-01-01

206

The effect of flooding regimes on decomposition of Polygonum pensylvanicum in playa wetlands (Southern Great Plains, USA)  

Microsoft Academic Search

Plants in playa wetlands are hypothesized to have high decomposition rates due to rapidly fluctuating water levels. Therefore, Polygonum pensylvanicum (a dominant playa species) decomposition rates were studied in relation to four water regimes (F1 (flooded 30% of 321 days), F2 (41%), F3 (58%), or F4 (100%)) in playa wetlands of the Southern Great Plains of Texas, 1996–1997. Decomposition rates

James T. Anderson; Loren M. Smith

2002-01-01

207

Water Conservation with Urban Landscape Plants  

E-print Network

Water shortages are a common problem in much of the southwest. Increasing urbanization and increasing population places greater demands on dwindling water supplies. Over half of the water used in urban areas of the southwest is used...

Hip, B. W.; Giordano, C.; Simpson, B.

208

Silica Removal During Lime Softening in Water Treatment Plant  

Microsoft Academic Search

Silica, SiO2, is typically found in well water supplies. Most of the silica found in well waters is a result of dissolving silica-containing rock. Silica content in brackish water is generally in the range of 20 to 60 ppm. In Salbukh water treatment plant, silica concentration of raw water is about 30 ppm. High concentration of silica causes membrane fouling

Ibrahim S. Al-Mutaz; Ibrahim Ali Al-Anezi

2004-01-01

209

Water treatment plant intelligent monitoring in large gas refinery  

Microsoft Academic Search

Water treatment plants have to provide good water quality and at the same time low operational costs. Owing to various physical, chemical and biological interactions water treatment processes are often difficult to handle and reliable predictions for the course of processes are difficult to obtain. Developing monitoring in Automation Control System is a major industrial concern since those systems are

Amir Firoozshahi; Li Mengyang

2010-01-01

210

ENERGY AND WATER OPTIMIZATION IN BIOFUEL PLANTS Ignacio E. Grossmann*  

E-print Network

1 ENERGY AND WATER OPTIMIZATION IN BIOFUEL PLANTS Ignacio E. Grossmann* , Mariano Martín Center, PA 15213, USA Abstract In this paper we address the topic of energy and water optimization to develop sustainable biofuel processes by means of a two-stage approach. 2 STRATEGY FOR ENERGY AND WATER

Grossmann, Ignacio E.

211

Coal power plant flue gas waste heat and water recovery  

Microsoft Academic Search

► We developed a transport membrane condenser to extract water vapor from flue gases. ► The recovered energy from water vapor improves boiler efficiency and saved water. ► We further developed the technology for coal-fired power plant flue gases. ► We validated the TMC performance for different flue gas conditions.

Dexin Wang; Ainan Bao; Walter Kunc; William Liss

2012-01-01

212

Filtration plant for drinking water James Tarchala [1  

E-print Network

Filtration plant for drinking water James Tarchala [1] Alexandre Selhorst [2] Cheny Thao [3] 1 2 3 Riley, Wang, Aaron Nolan (Not Pictured) 12/1/2014 #12;Reclaiming waste HEAT TO PRE- HEAT WATER IN a FACTORY HOT WATER SYSTEM Group 5: Joseph Von Arx(1) Aaron McKeown(2) Kyle Swanson(3) Ian Klecka(4) 1 2 3 4

Kostic, Milivoje M.

213

Energy requirement of water production in dual-purpose plants  

Microsoft Academic Search

In dual-purpose plants (DPPs) producing electricity and water, a realistic estimate for the energy requirement of water production is important since the cost of energy can be combined with equipment, operation and maintenance costs to arrive at the total cost of water production. In a multi-stage flash desalination system, the kind of technology currently being used in most of the

G. P. Maheshwari; M. Al-Ramadhan; M. Al-Abdulhadi

1995-01-01

214

The crystallization water of gypsum rocks is a relevant water source for plants.  

PubMed

Some minerals, like gypsum, hold water in their crystalline structure. Although still unexplored, the use of such crystallization water by organisms would point to a completely new water source for life, critical under dry conditions. Here we use the fact that the isotopic composition of free water differs from gypsum crystallization water to show that plants can use crystallization water from the gypsum structure. The composition of the xylem sap of gypsum plants during summer shows closer values to gypsum crystallization water than to free soil water. Crystallization water represents a significant water source for organisms growing on gypsum, especially during summer, when it accounts for 70-90% of the water used by shallow-rooted plants. Given the widespread occurrence of gypsum in dry lands throughout the Earth and in Mars, these results may have important implications for arid land reclamation and exobiology. PMID:25130772

Palacio, Sara; Azorín, José; Montserrat-Martí, Gabriel; Ferrio, Juan Pedro

2014-01-01

215

Costly Mistakes In Water Treatment Plant Design For Power Plant Projects  

Microsoft Academic Search

Water treatment cost is a relatively small slice of the operating budget in a typical power plant, generally less than 2 % of the total cost of operation. However, its impact on the plant heat rate, net capacity factor and project profitability can range from significant to disproportionately high. One area of particular concern is the high-purity water requirement in

Luis Carvalho

216

EXPERIENCE ON ULTRAFILTRATION MEMBRANE PLANT PERFORMANCE AT THE NEW GOREANGAB WATER RECLAMATION PLANT  

Microsoft Academic Search

The New Goreangab Water Reclamation Plant in Windhoek (NGWRP) uses an ultrafiltration membrane plant as a final barrier for the removal of pathogenic micro- organisms; this barrier follows a range of pre-treatment processes including ozonation and activated carbon filtration. The ultrafiltration membrane plant has been in production since May 2002 and performance has been monitored over the period of operation.

T. Theron-Beukes; E. Konig

217

Decomposition analysis of water footprint changes in a water-limited river basin: a case study of the Haihe River Basin, China  

NASA Astrophysics Data System (ADS)

Decomposition analysis of water footprint (WF) changes, or assessing the changes in WF and identifying the contributions of factors leading to the changes, is important to water resource management. However, conventional studies focus on WF from the perspective of administrative region rather than river basin. Decomposition analysis of WF changes from the perspective of the river basin is more scientific. To address this perspective, we built a framework in which the input-output (IO) model and the Structural Decomposition Analysis (SDA) model for WF could be implemented in a river basin by computing IO data for the river basin with the Generating Regional IO Tables (GRIT) method. This framework is illustrated in the Haihe River Basin (HRB), which is a typical water-limited river basin. It shows that the total WF in the HRB increased from 4.3 × 1010 m3 in 2002 to 5.6 × 1010 m3 in 2007, and the agriculture sector makes the dominant contribution to the increase. Both the WF of domestic products (internal) and the WF of imported products (external) increased, and the proportion of external WF rose from 29.1% to 34.4%. The technological effect was the dominant contributor to offsetting the increase of WF; however, the growth of WF caused by the economic structural effect and the scale effect was greater, so the total WF increased. This study provides insights about water challenges in the HRB and proposes possible strategies for the future, and serves as a reference for WF management and policy making in other water-limited river basins.

Zhi, Y.; Yang, Z. F.; Yin, X. A.

2013-12-01

218

78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Federal Register 2010, 2011, 2012, 2013, 2014

...Water-Cooled Nuclear Power Plants.'' This guide describes...water cooled nuclear power plants. ADDRESSES: Please...series. This series was developed to describe and make...water cooled nuclear power plants. This RG is being...

2013-06-12

219

Water use, productivity and interactions among desert plants  

SciTech Connect

Water plays a central role affecting all aspects of the dynamics in aridland ecosystems. Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. The ecological studies in this project revolve around one fundamental premise: that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process. In contrast, hydrogen is not fractionated during water uptake through the root. Soil water availability in shallow, deep, and/or groundwater layers vary spatially; therefore hydrogen isotope ratios of xylem sap provide a direct measure of the water source currently used by a plant. The longer-term record of carbon and hydrogen isotope ratios is recorded annually in xylem tissues (tree rings). The research in this project addresses variation in stable isotopic composition of aridland plants and its consequences for plant performance and community-level interactions.

Ehleringer, J.R.

1992-11-17

220

Economic Comparison of Waste Water Cleaning for Central Waste Water Treatment Plant and Decentralised System with Smaller Waste Water Treatment Plants  

Microsoft Academic Search

In presented paper two economic analysis of investments for integrated waste water collection and treatment in selected area are presented. The methods of Net present value (NPV) and Capitalised costs (CC) have been used to compare economic efficiency of construction central waste water treatment plant with collecting system and construction of decentralised waste water treatment plants with belonging collecting system

J. ZORKO; D. GORICANEC

221

The Dynamics of Plant Cell-Wall Polysaccharide Decomposition in Leaf-Cutting Ant Fungus Gardens  

Microsoft Academic Search

The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint

Isabel E. Moller; Henrik H. de Fine Licht; Jesper Harholt; William G. T. Willats; Jacobus J. Boomsma; Jerome Chave

2011-01-01

222

Decomposition in soil of tobacco plants with genetic modifications to lignin biosynthesis  

Microsoft Academic Search

Genetic modification of the amount, conformation and composition of lignin in plant materials is being explored both to understand better the process of lignin biosynthesis and with a view to enhancing forage digestibility or paper pulping properties. We have investigated the interaction between the effects of genetic modifications to lignin biosynthesis and the activity of decomposer organisms to provide information

D. W. Hopkins; E. A. Webster; J. A. Chudek; C. Halpin

2001-01-01

223

Evaluation of water treatment sludge as a catalyst for aqueous ozone decomposition  

Microsoft Academic Search

A new, novel, efficient, and stable green catalyst has been successfully used as a catalyst in aqueous ozone decomposition in acidic medium. The catalyst was characterized by using X-ray fluorescence (XRF), transmission electron microscope (TEM), scanning electron microscope (SEM), and X-ray diffraction (XRD) techniques. The sludge mainly consists of various metal and non-metal oxides. The effect of various experimental parameters

M. Muruganandham; S. H. Chen; J. J. Wu

2007-01-01

224

Water recovery using waste heat from coal fired power plants.  

SciTech Connect

The potential to treat non-traditional water sources using power plant waste heat in conjunction with membrane distillation is assessed. Researchers and power plant designers continue to search for ways to use that waste heat from Rankine cycle power plants to recover water thereby reducing water net water consumption. Unfortunately, waste heat from a power plant is of poor quality. Membrane distillation (MD) systems may be a technology that can use the low temperature waste heat (<100 F) to treat water. By their nature, they operate at low temperature and usually low pressure. This study investigates the use of MD to recover water from typical power plants. It looks at recovery from three heat producing locations (boiler blow down, steam diverted from bleed streams, and the cooling water system) within a power plant, providing process sketches, heat and material balances and equipment sizing for recovery schemes using MD for each of these locations. It also provides insight into life cycle cost tradeoffs between power production and incremental capital costs.

Webb, Stephen W.; Morrow, Charles W.; Altman, Susan Jeanne; Dwyer, Brian P.

2011-01-01

225

Waste wash water recycling in ready-mixed concrete plants  

Microsoft Academic Search

Production of large amounts of waste wash water coming from ready-mixed concrete plants leads to problems of environmental impact. National laws usually prohibit the disposal of such types of water, due to their extremely high pH value and suspended matter amount, and require the water to be treated prior to discharge. prEN 1008 provides for recycling waste water in the

Franco Sandrolini; Elisa Franzoni

2001-01-01

226

Survey of Microbial Enzymes in Soil, Water, and Plant Microenvironments  

PubMed Central

Detection of microbial enzymes in natural environments is important to understand biochemical activities and to verify the biotechnological potential of the microorganisms. In the present report, 346 isolates from soil, water, and plants were screened for enzyme production (caseinase, gelatinase, amylase, carboxymethyl cellulase, and esterase). Our results showed that 89.6% of isolates produced at least one tested enzyme. A predominance of amylase in soil samples, carboxymethyl cellulase in plants, as well as esterase and gelatinase in water was observed. Interesting enzymatic profiles were found in some microenvironments, suggesting specificity of available nutrients and/or natural selection. This study revealed the potential of microorganisms present in water, soil, and plant to produce important enzymes for biotechnological exploration. A predominance of certain enzymes was found, depending on the type of environmental sample. The distribution of microbial enzymes in soil, water and plants has been little exploited in previous reports. PMID:24847390

Alves, Priscila Divina Diniz; Siqueira, Flávia de Faria; Facchin, Susanne; Horta, Carolina Campolina Rebello; Victória, Júnia Maria Netto; Kalapothakis, Evanguedes

2014-01-01

227

Water Pinch Success Story at Solutia's Krummrich Plant  

E-print Network

A site-wide water conservation and wastewater minimization study complementing the previous energy study was undertaken by a consulting engineering company specializing in Pinch Analysis for Solutia’s W.G. Krummrich plant in Sauget, Illinois...

Kumana, J. D.

228

MICROORGANISMS AND HIGHER PLANTS FOR WASTE WATER TREATMENT  

EPA Science Inventory

Batch experiments were conducted to compare the waste water treatment efficiencies of plant-free microbial filters with filters supporting the growth of reeds (Phragmites communis), cattail (Typha latifolia), rush (Juncus effusus), and bamboo (Bambusa multiplex). The experimental...

229

Sacramento River Water Treatment Plant Intake Pier & Access Bridge, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

230

COMPUTER COST MODELS FOR POTABLE WATER TREATMENT PLANTS  

EPA Science Inventory

A series of computer programs have been developed which calculate costs for specific unit treatment processes used in water treatment plants. The programs contained in this report are as follows: chlorination, chlorine dioxide, ozone, and granular activated carbon adsorption. Tab...

231

Macrophyte Decomposition Rates in the Tres Rios Constructed Treatment Wetland: Preliminary Results!  

E-print Network

& Childers 2009). But plant decomposition is also an important process in high-nutrient wetlands near the open water to near the shore. · We divided the 6 primary plant species in the system into 3 (Inflow to Outflow) and within-marsh variance (Open Water to Shore).! Introduction! Acknowledgements! We

Hall, Sharon J.

232

Optimisation of complex water supply systems with water quality, hydraulic and treatment plant aspects  

Microsoft Academic Search

A model for optimal operation of a complex water supply system for drinking water and with water quality, hydraulic and desalination treatment plants developed by Cohen and others has been applied to a realistic regional network, in which water quality is defined by salinity, magnesium and sulphur. The model considers the hydraulics of the network, including pump stations, boosters and

Dani Cohen; Uri Shamir; Gideon Sinai

2009-01-01

233

Recycling of filter backwash water and alum sludge for reuse in water treatment plants. Technical report  

Microsoft Academic Search

The feasibility of recycling backwash water and alum sludge generated from water-purification plants has been investigated. The waste recycle system presented here consists of (a) recycling the filter backwash water to the intake system for reproduction of potable water, (b) dividing the combined sludge into two fractions for alum solubilization, respectively, in an acid reactor and an alkaline reactor, (c)

M. Krofta; L. K. Wang

1988-01-01

234

PLAYING CATCH-UP WITH CATCHMENT WATER QUALITY THE VAALKOP WATER TREATMENT PLANT UPGRADE CASE STUDY  

Microsoft Academic Search

The first phase of the Vaalkop water treatment plant was commissioned more than 30 years ago soon after the Vaalkop Dam was constructed. The quality of the water abstracted from the Vaalkop Dam was such that a conventional water treatment train utilizing flocculation, settling, sand filtration and disinfection was sufficient to treat the water to potable standards. However, many changes

JJ van der Walt; CJ van der Walt

235

Onset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water dynamics  

E-print Network

Onset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water hysteresis in canopy conductance, hydraulic lift, and compensatory root water uptake during extended drying effective is dictated by soil hydraulic properties and surrogates for atmospheric water vapor demand

Katul, Gabriel

236

OZONATION AND BIOLOGICAL STABILITY OF WATER IN AN OPERATING WATER TREATMENT PLANT  

EPA Science Inventory

Ozonation of drinking water may adversely affect the biological stability of the inished water. his study was designed assess the effect of ozone as a preoxidant on the nutrient status of water treated in a full-scale water treatment plant. he study was conducted over a ten week ...

237

Thermal decomposition of methanol in the sonolysis of methanol-water mixtures. Spin-trapping evidence for isotope exchange reactions  

SciTech Connect

The spin trap 3,5-dibromo-4-nitrosobenzenesulfonate was used to monitor the yield of free radicals produced during sonolysis of water-methanol mixtures. Methyl radicals and CH/sub 2/OH radicals were observed as well as the isotopically mixed radicals CH/sub 2/D and CHD/sub 2/ when CH/sub 3/OD:D/sub 2/O mixtures were studied. The results clearly show that thermal decomposition of methanol to methyl radicals occurs in the gas phase. The methyl radical yield rises sharply at very low concentrations of methanol, reaches a maximum at 5 mol dm/sup -3/ in water and decreases to a smaller value in methanol. The yield of methyl radicals as a function of methanol concentration is discussed in terms of the different factors influencing the sonochemistry.

Krishna, C.M.; Lion, Y.; Kondo, T.; Riesz, P.

1987-11-05

238

Phytoaccumulation of trace elements by wetland plants. 2: Water hyacinth  

Microsoft Academic Search

Wetland plants are being used successfully for the phytoremediation of trace elements in natural and constructed wetlands. This study demonstrates the potential of water hyacinth (Eichhornia crassipes), an aquatic floating plant, for the phytoremediation of six trace elements. The ability of water hyacinth to take up and translocate six trace elements--As(V), Cd(II), Cr(VI), Cu(II), Ni(II), and Se(VI)--was studied under controlled

Y. L. Zhu; A. M. Zayed; J. H. Qian; M. de Souza; N. Terry

2009-01-01

239

Efficient decomposition of a new fluorochemical surfactant: Perfluoroalkane disulfonate to fluoride ions in subcritical and supercritical water.  

PubMed

Decomposition of (-)O3SC3F6SO3(-) in subcritical and supercritical water was investigated, and the results were compared with the results for C3F7SO3(-). This is the first report on the decomposition of perfluoroalkane disulfonates, which are being introduced in electronics industry as greener alternatives to environmentally persistent and bioaccumulative perfluoroalkyl surfactants. Addition of zerovalent iron to the reaction system dramatically increased the yield of F(-) in the reaction solution: when the reaction of (-)O3SC3F6SO3(-) was carried out in subcritical water at 350°C for 6h, the F(-) yield was 70%, which was 23times the yield without zerovalent iron. Prolonged reaction increased the F(-) formation: after 18h, the F(-) yield from the reaction of (-)O3SC3F6SO3(-) reached 81%, which was 2.1times the F(-) yield from the reaction of C3F7SO3(-). Although the reactivity of FeO toward these substrates was lower than zerovalent iron in subcritical water, the reactivity was enhanced when the reaction temperature was elevated to supercritical state, at which temperature FeO underwent in situ disproportionation to form zerovalent iron, which acted as the reducing agent. When the reaction of (-)O3SC3F6SO3(-) was carried out in the presence of FeO in supercritical water at 380°C for 18h, the F(-) yield reached 92%, which was the highest yield among tested. PMID:25015226

Hori, Hisao; Saito, Hiroki; Sakai, Hidenori; Kitahara, Toshiyuki; Sakamoto, Takehiko

2014-07-01

240

7. ONE OF THREE CIRCULATING WATER PUMPS FOR STEAM PLANT, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. ONE OF THREE CIRCULATING WATER PUMPS FOR STEAM PLANT, LOCATED ON FIRST FLOOR UNDER TURBINE DECK. VIEW OF PUMP LOCATED FARTHEST NORTH. November 13, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

241

A new look at water transport regulation in plants.  

PubMed

Plant function requires effective mechanisms to regulate water transport at a variety of scales. Here, we develop a new theoretical framework describing plant responses to drying soil, based on the relationship between midday and predawn leaf water potentials. The intercept of the relationship (?) characterizes the maximum transpiration rate per unit of hydraulic transport capacity, whereas the slope (?) measures the relative sensitivity of the transpiration rate and plant hydraulic conductance to declining water availability. This framework was applied to a newly compiled global database of leaf water potentials to estimate the values of ? and ? for 102 plant species. Our results show that our characterization of drought responses is largely consistent within species, and that the parameters ? and ? show meaningful associations with climate across species. Parameter ? was ?1 in most species, indicating a tight coordination between the gas and liquid phases of water transport, in which canopy transpiration tended to decline faster than hydraulic conductance during drought, thus reducing the pressure drop through the plant. The quantitative framework presented here offers a new way of characterizing water transport regulation in plants that can be used to assess their vulnerability to drought under current and future climatic conditions. PMID:24985503

Martínez-Vilalta, Jordi; Poyatos, Rafael; Aguadé, David; Retana, Javier; Mencuccini, Maurizio

2014-10-01

242

Surface water pollution by herbicides from effluents of waste water treatment plants  

Microsoft Academic Search

Herbicide loads of urban and rural waste water treatment plant effluents were calculated over a one-year period by measuring the herbicide concentrations in 14-day mixed samples. More than three quarters of the total herbicide load of the effluent of the rural waste water treatment plant consists of isoproturon. Particularly large amounts of this substance contribute to the total herbicide load

Walter Schüssler

1998-01-01

243

South Florida ornamental plant grower perspectives: water conservation management practices 1  

E-print Network

ABE 369 South Florida ornamental plant grower perspectives: water conservation management practices ornamental plant grower perspectives: water conservation management.... 2 water quantity and quality historically experienced periods of extended droughts which threaten production capabilities thus making water

Migliaccio, Kati White

244

Multibubble plasma production and solvent decomposition in water by slot-excited microwave discharge  

SciTech Connect

Intense microwaves are injected from a slot antenna into water partly filling a metal vessel. When the vessel is evacuated to saturated vapor pressure ({approx}5x10{sup 3} Pa) of water, microwave breakdown gives rise to plasmas in many bubbles in the boiling water. Gas bubbling technique enables production of multibubble plasmas in water even at atmospheric pressure. Optical emissions from the exited species are investigated to identify radical species in water. In order to demonstrate application to purification of polluted water, methylene blue and trichlorethylene solution in 8 l water were observed to rapidly decrease with multibubble plasma treatment.

Ishijima, T.; Hotta, H.; Sugai, H.; Sato, M. [Plasma Nanotechnology Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Honda Electronics Corporation, 20 Oyamazuka, Oiwa-cho, Toyohashi 441-3193 (Japan)

2007-09-17

245

Iowa's first electrodialysis reversal water treatment plant  

Microsoft Academic Search

In 1979 the City of Washington was notified by the Iowa Department of Natural Resources (IDNR) that the City was in violation of the radium standard for drinking water. The City of Washington authorized an engineering study to determine the most cost-effective and practical way to remove radium and, at the same time, improve overall water quality. Several possible treatment

John Hays

2000-01-01

246

Cadaver decomposition in terrestrial ecosystems  

NASA Astrophysics Data System (ADS)

A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.

Carter, David O.; Yellowlees, David; Tibbett, Mark

2007-01-01

247

Cadaver decomposition in terrestrial ecosystems.  

PubMed

A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems. PMID:17091303

Carter, David O; Yellowlees, David; Tibbett, Mark

2007-01-01

248

INORGANIC CHEMICAL CHARACTERIZATION OF WATER TREATMENT PLANT RESIDUALS  

EPA Science Inventory

The study obtained field data on the inorganic contaminants and constituents in residuals produced by Water Treatment Plants (WTPs). Eight WTPs were studied based on treatment technology, contamination or suspected contamination of raw water, and efficiency in the removal of cont...

249

ARSENIC REMOVAL FROM DRINKING WATER BY IRON REMOVAL PLANTS  

EPA Science Inventory

This report documents a long term performance study of two iron removal water treatment plants to remove arsenic from drinking water sources. Performance information was collected from one system located in midwest for one full year and at the second system located in the farwest...

250

Hydraulic modelling of drinking water treatment plant operations  

Microsoft Academic Search

The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand filtration and cascade and tower aeration. Using this treatment step library, a

G. I. M. Worm; G. A. M. Mesman; K. M. Van Schagen; K. J. Borger; L. C. Rietveld

2009-01-01

251

Plants for water recycling, oxygen regeneration and food production  

NASA Technical Reports Server (NTRS)

During long-duration space missions that require recycling and regeneration of life support materials the major human wastes to be converted to usable forms are CO2, hygiene water, urine and feces. A Controlled Ecological Life Support System (CELSS) relies on the air revitalization, water purification and food production capabilities of higher plants to rejuvenate human wastes and replenish the life support materials. The key processes in such a system are photosynthesis, whereby green plants utilize light energy to produce food and oxygen while removing CO2 from the atmosphere, and transpiration, the evaporation of water from the plant. CELSS research has emphasized the food production capacity and efforts to minimize the area/volume of higher plants required to satisfy all human life support needs. Plants are a dynamic system capable of being manipulated to favour the supply of individual products as desired. The size and energy required for a CELSS that provides virtually all human needs are determined by the food production capacity. Growing conditions maximizing food production do not maximize transpiration of water; conditions favoring transpiration and scaling to recycle only water significantly reduces the area, volume, and energy inputs per person. Likewise, system size can be adjusted to satisfy the air regeneration needs. Requirements of a waste management system supplying inputs to maintain maximum plant productivity are clear. The ability of plants to play an active role in waste processing and the consequence in terms of degraded plant performance are not well characterized. Plant-based life support systems represent the only potential for self sufficiency and food production in an extra-terrestrial habitat.

Bubenheim, D. L.

1991-01-01

252

Non-Additive effects on decomposition from mixing litter of the invasive Mikania micrantha H.B.K. with native plants.  

PubMed

A common hypothesis to explain the effect of litter mixing is based on the difference in litter N content between mixed species. Although many studies have shown that litter of invasive non-native plants typically has higher N content than that of native plants in the communities they invade, there has been surprisingly little study of mixing effects during plant invasions. We address this question in south China where Mikania micrantha H.B.K., a non-native vine, with high litter N content, has invaded many forested ecosystems. We were specifically interested in whether this invader accelerated decomposition and how the strength of the litter mixing effect changes with the degree of invasion and over time during litter decomposition. Using litterbags, we evaluated the effect of mixing litter of M. micrantha with the litter of 7 native resident plants, at 3 ratios: M1 (1?4,?=?exotic:native litter), M2 (1?1) and M3 (4?1,?=?exotic:native litter) over three incubation periods. We compared mixed litter with unmixed litter of the native species to identify if a non-additive effect of mixing litter existed. We found that there were positive significant non-additive effects of litter mixing on both mass loss and nutrient release. These effects changed with native species identity, mixture ratio and decay times. Overall the greatest accelerations of mixture decay and N release tended to be in the highest degree of invasion (mix ratio M3) and during the middle and final measured stages of decomposition. Contrary to expectations, the initial difference in litter N did not explain species differences in the effect of mixing but overall it appears that invasion by M. micrantha is accelerating the decomposition of native species litter. This effect on a fundamental ecosystem process could contribute to higher rates of nutrient turnover in invaded ecosystems. PMID:23840435

Chen, Bao-Ming; Peng, Shao-Lin; D'Antonio, Carla M; Li, Dai-Jiang; Ren, Wen-Tao

2013-01-01

253

USE of mine pool water for power plant cooling.  

SciTech Connect

Water and energy production issues intersect in numerous ways. Water is produced along with oil and gas, water runs off of or accumulates in coal mines, and water is needed to operate steam electric power plants and hydropower generating facilities. However, water and energy are often not in the proper balance. For example, even if water is available in sufficient quantities, it may not have the physical and chemical characteristics suitable for energy or other uses. This report provides preliminary information about an opportunity to reuse an overabundant water source--ground water accumulated in underground coal mines--for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL), which has implemented a water/energy research program (Feeley and Ramezan 2003). Among the topics studied under that program is the availability and use of ''non-traditional sources'' of water for use at power plants. This report supports NETL's water/energy research program.

Veil, J. A.; Kupar, J. M .; Puder, M. G.

2006-11-27

254

Designing and constructing the Trap Falls water treatment plant  

Microsoft Academic Search

The challenge of designing and building a 94-ML\\/d (25-mgd) water treatment plant to meet new water quality standards was successfully accomplished by the Bridgeport (Conn.) Hydraulic Company. A constricted site located near a highway and several dwellings called for an aesthetic architectural solution as well as the use of unusual water treatment technology. A fast-track design and construction program achieved

Mark L. Johnson; Peter W. Doe

1983-01-01

255

Water vulnerabilities for existing coal-fired power plants.  

SciTech Connect

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements the Existing Plants Research Program's overall research effort by evaluating water issues that could impact power plants. Water consumption by all users in the United States over the 2005-2030 time period is projected to increase by about 7% (from about 108 billion gallons per day [bgd] to about 115 bgd) (Elcock 2010). By contrast, water consumption by coal-fired power plants over this period is projected to increase by about 21% (from about 2.4 to about 2.9 bgd) (NETL 2009b). The high projected demand for water by power plants, which is expected to increase even further as carbon-capture equipment is installed, combined with decreasing freshwater supplies in many areas, suggests that certain coal-fired plants may be particularly vulnerable to potential water demand-supply conflicts. If not addressed, these conflicts could limit power generation and lead to power disruptions or increased consumer costs. The identification of existing coal-fired plants that are vulnerable to water demand and supply concerns, along with an analysis of information about their cooling systems and related characteristics, provides information to help focus future research and development (R&D) efforts to help ensure that coal-fired generation demands are met in a cost-effective manner that supports sustainable water use. This study identified coal-fired power plants that are considered vulnerable to water demand and supply issues by using a geographical information system (GIS) that facilitated the analysis of plant-specific data for more than 500 plants in the NETL's Coal Power Plant Database (CPPDB) (NETL 2007a) simultaneously with 18 indicators of water demand and supply. Two types of demand indicators were evaluated. The first type consisted of geographical areas where specific conditions can generate demand vulnerabilities. These conditions include high projected future water consumption by thermoelectric power plants, high projected future water consumption by all users, high rates of water withdrawal per square mile (mi{sup 2}), high projected population increases, and areas projected to be in a water crisis or conflict by 2025. The second type of demand indicator was plant specific. These indicators were developed for each plant and include annual water consumption and withdrawal rates and intensities, net annual power generation, and carbon dioxide (CO{sub 2}) emissions. The supply indictors, which are also area based, include areas with low precipitation, high temperatures, low streamflow, and drought. The indicator data, which were in various formats (e.g., maps, tables, raw numbers) were converted to a GIS format and stored, along with the individual plant data from the CPPDB, in a single GIS database. The GIS database allowed the indicator data and plant data to be analyzed and visualized in any combination. To determine the extent to which a plant would be considered 'vulnerable' to a given demand or supply concern (i.e., that the plant's operations could be affected by water shortages represented by a potential demand or supply indicator), criteria were developed to categorize vulnerability according to one of three types: major, moderate, or not vulnerable. Plants with at least two major demand indicator values and/or at least four moderate demand indicator values were considered vulnerable to demand concerns. By using this approach, 144 plants were identified as being subject to demand concerns only. Plants with at least one major supply indicator value and/or at least two moderate supply indicator values were considered vulnerable to supply concerns. By using this approach, 64 plants were identified as being subject to supply concerns only. In addition, 139 plants were identified as subject to both demand and supply concerns. Therefore, a total of 347 plants were considere

Elcock, D.; Kuiper, J.; Environmental Science Division

2010-08-19

256

Ecological role of reindeer summer browsing in the mountain birch (Betula pubescens ssp. czerepanovii) forests: effects on plant defense, litter decomposition, and soil nutrient cycling.  

PubMed

Mammalian herbivores commonly alter the concentrations of secondary compounds in plants and, by this mechanism, have indirect effects on litter decomposition and soil carbon and nutrient cycling. In northernmost Fennoscandia, the subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests are important pasture for the semidomestic reindeer (Rangifer tarandus). In the summer ranges, mountain birches are intensively browsed, whereas in the winter ranges, reindeer feed on ground lichens, and the mountain birches remain intact. We analyzed the effect of summer browsing on the concentrations of secondary substances, litter decomposition, and soil nutrient pools in areas that had been separated as summer or winter ranges for at least 20 years, and we predicted that summer browsing may reduce levels of secondary compounds in the mountain birch and, by this mechanism, have an indirect effect on the decomposition of mountain birch leaf litter and soil nutrient cycling. The effect of browsing on the concentration of secondary substances in the mountain birch leaves varied between different years and management districts, but in some cases, the concentration of condensed tannins was lower in the summer than in the winter ranges. In a reciprocal litter decomposition trial, both litter origin and emplacement significantly affected the litter decomposition rate. Decomposition rates were faster for the litter originating from and placed into the summer range. Soil inorganic nitrogen (N) concentrations were higher in the summer than in the winter ranges, which indicates that reindeer summer browsing may enhance the soil nutrient cycling. There was a tight inverse relationship between soil N and foliar tannin concentrations in the winter range but not in the summer range. This suggests that in these strongly nutrient-limited ecosystems, soil N availability regulates the patterns of resource allocation to condensed tannins in the absence but not in the presence of browsing. PMID:17123112

Stark, Sari; Julkunen-Tiitto, Riitta; Kumpula, Jouko

2007-03-01

257

To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell.  

PubMed

Settlement of cyanobacterial bloom biomass (CBB) into sediments in eutrophic lakes often induced the occurrence of black water agglomerate and then water quality deterioration. This study investigated the effect of sediment microbial fuel cell (SMFC) on CBB removal in sediments and related water pollution. Sediment bulking and subsequent black water from decomposition of settled CBB happened without SMFC, but were not observed over 100-day experiments with SMFC employment. While CBB in sediments improved power production from SMFC, the removal efficiency of organic matters in CBB-amended sediments with SMFC was significantly lower than that without SMFC. Pyrosequencing analysis showed higher abundances of the fermentative Clostridium and acetoclastic methanogen in CBB-amended bulk sediments without SMFC than with SMFC at the end of experiments. Obviously, SMFC operation changed the microbial community in CBB-amended sediments, and delayed the CBB degradation against sediment bulking. Thus, SMFC could be potentially applied as pollution prevention in CBB-settled and sensitive zones in shallow lakes. PMID:25621829

Zhou, Yan-Li; Jiang, He-Long; Cai, Hai-Yuan

2015-04-28

258

The potential of dual-energy computed tomography for quantitative decomposition of soft tissues to water, protein and lipid in brachytherapy  

NASA Astrophysics Data System (ADS)

Dosimetric accuracy of radiation treatment planning in brachytherapy depends on knowledge of tissue composition. It has been speculated that soft tissues can be decomposed to water, lipid and protein. The aim of our work is to evaluate the accuracy of such tissue decomposition. Selected abdominal soft tissues, whose average elemental compositions were taken from literature, were decomposed using dual energy computed tomography to water, lipid and protein via the three-material decomposition method. The quality of the decomposition was assessed using relative differences between (i) mass energy absorption and (ii) mass energy attenuation coefficients of the analyzed and approximated tissues. It was found that the relative differences were less than 2% for photon energies larger than 10 keV. The differences were notably smaller than the ones for water as the transport and dose scoring medium. The choice of the water, protein and lipid triplet resulted in negative elemental mass fractions for some analyzed tissues. As negative elemental mass fractions cannot be used in general purpose particle transport computer codes using the Monte Carlo method, other triplets should be used for the decomposition. These triplets may further improve the accuracy of the approximation as the differences were mainly caused by the lack of high-Z materials in the water, protein and lipid triplet.

Malusek, A.; Karlsson, M.; Magnusson, M.; Alm Carlsson, G.

2013-02-01

259

Does pre-dawn water potential reflect conditions of equilibrium in plant and soil water status?  

NASA Astrophysics Data System (ADS)

Variation in base water potential ( ?b, a daily maximum level of plant water potential, which is presumed to correspond to the equilibrium between soil and plant water potentials) was examined in shoots of Picea abies and Vaccinium myrtillus with respect to soil (available water storage, water potential, temperature) and atmospheric (temperature, relative humidity, vapour pressure deficit) conditions. The available soil water storage (W tr) accounted for 77% of the dynamics of ?b, while the influence of atmospheric factors became evident under high evaporative demand. ?b was not always observable immediately before dawn, but on 30% of observation days, the recovery continued up to an hour or two after dawn. Full equilibrium between soil and plant water potentials in P. abies in northern conditions is rather improbable by dawn in summer-time, because of the shortness of the dark period and probable night-time transpiration in the case of high atmospheric vapour pressure deficit.

Sellin, Arne

1999-02-01

260

Optimization of a Chilled Water Plant Using a Forward Plant Model  

E-print Network

problem and can be solved with the generalized reduced gradient nonlinear solver. The application of this model is illustrated with a practical chilled water system. INTRODUCTION A chiller plant produces chilled water (ChW) and transports... it to end users, such as air handling units, through piping. Ever since 1990, traditional ChW plant design has begun utilizing a primary- secondary loop configuration. The imbalance in flow between the primary and secondary circuits results in flow...

Zhang, Z.; Turner, W. D.; Chen, Q.; Xu, C.; Deng, S.

2010-01-01

261

Plants Clean Air and Water for Indoor Environments  

NASA Technical Reports Server (NTRS)

Wolverton Environmental Services Inc., founded by longtime government environmental scientist B.C. "Bill" Wolverton, is an environmental consulting firm that gives customers access to the results of his decades of cutting-edge bioremediation research. Findings about how to use plants to improve indoor air quality have been published in dozens of NASA technical papers and in the book, "How to Grow Fresh Air: 50 Houseplants That Purify Your Home or Office." The book has now been translated into 12 languages and has been on the shelves of bookstores for nearly 10 years. A companion book, "Growing Clean Water: Nature's Solution to Water Pollution," explains how plants can clean waste water. Other discoveries include that the more air that is allowed to circulate through the roots of the plants, the more effective they are at cleaning polluted air; and that plants play a psychological role in welfare in that people recover from illness faster in the presence of plants. Wolverton Environmental is also working in partnership with Syracuse University, to engineer systems consisting of modular wicking filters tied into duct work and water supplies, essentially tying plant-based filters into heating, ventilation, and air conditioning (HVAC) systems. Also, the company has recently begun to assess the ability of the EcoPlanter to remove formaldehyde from interior environments. Wolverton Environmental is also in talks with designers of the new Stennis Visitor's Center, who are interested in using its designs for indoor air-quality filters

2007-01-01

262

WATER TREATMENT PLANT OPTIMIZATION BY CONTROLLING THE SUSPENDED SOLIDS PHYSICOCHEMICAL ENVIRONMENT  

Microsoft Academic Search

Optimizing water treatment plant operation is a concept should be applied to all plants because some operational improvements can always be made. Optimization at a water treatment plant can be considered achieved when certain goals are being met to attain the most efficient use of the water treatment plant facilities. The most important goals are to reduce the water wastes,

Kamal El-Nahhas

263

Plant water uptake strategies to cope with stochastic rainfall  

NASA Astrophysics Data System (ADS)

We develop and compare two hydraulically-based schemes of the xylem structure of an individual plant. The dynamics of water uptake are analyzed under random conditions through the modeling of rainfall as a stochastic process. The two hydraulic schemes differ in the modeling of the root ability to cooperate, i.e., the capacity of roots to increase the water uptake from the wetter soil layers when other parts of the soil are dry (compensation effect) and to transfer water from moister into drier soil layers (water redistribution effect). Both compensation and water redistribution are direct consequences of the hydraulic structure of the root system, which is modeled here considering two contrasting cases corresponding to non-interacting uptake paths from different soil layers, and converging uptake paths. Only the latter hydraulic architecture allows for compensation and water redistribution. Another important difference between the hydraulic schemes is the stomatal response to soil dryness. When the soil water is unevenly distributed in the soil layers, the differences in the hydraulic schemes emerge. In semi-arid climates, plants characterized by a cooperative root system are shown to be less prone to water stress. In contrast, plants with non-interacting roots result to be better fit to humid climates, where the probability of droughts is small.

Tron, Stefania; Laio, Francesco; Ridolfi, Luca

2013-03-01

264

77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Federal Register 2010, 2011, 2012, 2013, 2014

...Water-Cooled Nuclear Power Plants.'' This guide...cooled nuclear power plants. DATES: Submit...currently being developed or improvements...This series was developed to describe and...Water-Cooled Nuclear Power Plants,'' is...

2012-12-07

265

Wetlands: Water, Wildlife, Plants, and People.  

ERIC Educational Resources Information Center

Describes wetlands and explains their importance to man and ecology. Delineates the role of water in wetlands. Describes how wetlands are classified: estuarine, riverine, lacustrine, palustrine, and marine. Accompanying article is a large, color poster on wetlands. Describes an activity where metaphors are used to explore the functions of…

Vandas, Steve

1992-01-01

266

Water use, productivity and interactions among desert plants. Final report  

SciTech Connect

Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

Ehleringer, J.R.

1992-11-17

267

Water use, productivity and interactions among desert plants  

SciTech Connect

Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

Ehleringer, J.R.

1992-11-17

268

Optimal plant water-use strategies under stochastic rainfall  

NASA Astrophysics Data System (ADS)

Plant hydraulic traits have been conjectured to be coordinated, thereby providing plants with a balanced hydraulic system that protects them from cavitation while allowing an efficient transport of water necessary for photosynthesis. In particular, observations suggest correlations between the water potentials at which xylem cavitation impairs water movement and the one at stomatal closure, and between maximum xylem and stomatal conductances, begging the question as to whether such coordination emerges as an optimal water-use strategy under unpredictable rainfall. Here mean transpiration is used as a proxy for long-term plant fitness and its variations as a function of the water potentials at 50% loss of stem conductivity due to cavitation and at 90% stomatal closure are explored. It is shown that coordination between these hydraulic traits is necessary to maximize , with rainfall patterns altering the optimal range of trait values. In contrast, coordination between ecosystem-level conductances appears not necessary to maximize . The optimal trait ranges are wider under drier than under mesic conditions, suggesting that in semiarid systems different water use strategies may be equally successful. Comparison with observations across species from a range of ecosystems confirms model predictions, indicating that the coordinated functioning of plant organs might indeed emerge from an optimal response to rainfall variability.

Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Porporato, Amilcare

2014-07-01

269

Animal or Plant: Which Is the Better Fog Water Collector?  

PubMed Central

Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base where less fog water is available. Differences in the fog-water collecting abilities in animals and plants have never been addressed. Here we place beetles and grass side-by-side in a fog chamber and measure the amount of water they collect over time. Based on the accumulated amount of water over a two hour period, grass is the better fog collector. However, in contrast to the episodic cascading water run-off from the grass, the beetles obtain water in a steady flow from their elytra. This steady trickle from the beetles' elytra to their mouth could ensure that even short periods of fog basking – while exposed to predators – will yield water. Up to now there is no indication of specialised surface properties on the grass leafs, but the steady run-off from the beetles could point to specific property adaptations of their elytra surface. PMID:22509331

Nørgaard, Thomas; Ebner, Martin; Dacke, Marie

2012-01-01

270

Macroscopic modeling of plant water uptake: soil and root resistances  

NASA Astrophysics Data System (ADS)

The macroscopic physically-based plant root water uptake (RWU) model, based on water-potential-gradient formulation (Vogel et al., 2013), was used to simulate the observed soil-plant-atmosphere interactions at a forest site located in a temperate humid climate of central Europe and to gain an improved insight into the mutual interplay of RWU parameters that affects the soil water distribution in the root zone. In the applied RWU model, the uptake rates are directly proportional to the potential gradient and indirectly proportional to the local soil and root resistances to water flow. The RWU algorithm is implemented in a one-dimensional dual-continuum model of soil water flow based on Richards' equation. The RWU model is defined by four parameters (root length density distribution, average active root radius, radial root resistance, and the threshold value of the root xylem potential). In addition, soil resistance to water extraction by roots is related to soil hydraulic conductivity function and actual soil water content. The RWU model is capable of simulating both the compensatory root water uptake, in situations when reduced uptake from dry layers is compensated by increased uptake from wetter layers, and the root-mediated hydraulic redistribution of soil water, contributing to more natural soil moisture distribution throughout the root zone. The present study focusses on the sensitivity analysis of the combined soil water flow and RWU model responses in respect to variations of RWU model parameters. Vogel T., M. Dohnal, J. Dusek, J. Votrubova, and M. Tesar. 2013. Macroscopic modeling of plant water uptake in a forest stand involving root-mediated soil-water redistribution. Vadose Zone Journal, 12, 10.2136/vzj2012.0154.

Vogel, Tomas; Votrubova, Jana; Dohnal, Michal; Dusek, Jaromir

2014-05-01

271

Oxygen plants for coal gasification: Experience at the Cool Water GCC (gasification combined cycle) Power Plant: Final report  

Microsoft Academic Search

This report presents the results of a study conducted by Airco-BOC for EPRI to assess performance of the Cool Water Oxygen Plant as it relates to the Cool Water Coal Gasification Program's requirements and evaluate alternate supply arrangements for future larger gasifier based combined cycle power plants. The Cool Water Oxygen Plant is the first application of a dedicated oxygen

R. A. Petras; R. A. Mostello; A. P. Ko

1987-01-01

272

Predawn plant water potential does not necessarily equilibrate with soil water potential under well-watered conditions  

Microsoft Academic Search

Predawn leaf water potential (Ow) and xylem pressure potential (Op) are expected to be in equilibrium with the soil water potential (soil Ow) around roots of well-watered plants. We surveyed 21 plant species (desert, chaparral, and coastal salt marsh species, as well as two temperate tree and two crop species) for departures from this expectation and for two potential mechanisms

L. A. Donovan; M. J. Linton; J. H. Richards

2001-01-01

273

Plant Response to Differential Soil Water Content and Salinity  

NASA Astrophysics Data System (ADS)

Root-zone soil water content is extremely dynamic, governed by complex and coupled processes such as root uptake, irrigation, evaporation, and leaching. Root uptake of water and nutrients is influenced by these conditions and the processes involved. Plant roots are living and functioning in a dynamic environment that is subjected to extreme changes over relatively short time and small distances. In order to better manage our agricultural resources and cope with increasing constraints of water limitation, environmental concerns and climate change, it is vital to understand plants responses to these changes in their environment. We grew chick pea (Cicer arietinum) plants, in boxes of 30 x 25 x 1 cm dimensions filled with fine sand. Layers of coarse sand (1.5 cm thick) were embedded in the fine-sand media to divide the root growth environment into sections that were hydraulically disconnected from each other. This way, each section could be independently treated with differential levels of water and salinity. The root growth and distribution in the soil was monitored on daily bases using neutron radiography. Daily water uptake was measured by weighing the containers. Changes of soil water content in each section of the containers were calculated from the neutron radiographs. Plants that part of their root system was stressed with drought or salinity showed no change in their daily water uptake rate. The roots in the stressed sections stayed turgid during the stress period and looked healthy in the neutron images. However the uptake rate was severely affected when the soil in the non-stressed section started to dry. The plants were then fully irrigated with water and the water uptake rate recovered to its initial rate shortly after irrigation. The neutron radiographs clearly illustrated the shrinkage and recovery of the roots under stress and the subsequent relief. This cycle was repeated a few times and the same trend could be reproduced. Our results show that plants' response to water- or salinity-stress ranges from full compensation to severe reduction in transpiration, depending on the availability of water in their surrounding soil. Results of applying different treatments of salinity and drought will be shown. Available models of root water uptake will be employed to simulate the obtained results.

Moradi, A. B.; Dara, A.; Kamai, T.; Ngo, A.; Walker, R.; Hopmans, J. W.

2011-12-01

274

Response of floodplain grassland plant communities to altered water regimes  

Microsoft Academic Search

Floodplain grasslands are often composed of a mosaic of plant communities controlled by hydrological regime. This article\\u000a examines the sensitivity of floodplain grassland plant communities to water regime using reciprocal transplantation of an\\u000a inundation grassland and a flood-meadow within an English floodplain. Experimental treatments comprised control, transplanted\\u000a and lifted plots; the last treatment, in order to elucidate any disturbance effects

Sarah E. Toogood; Chris B. Joyce; Stephen Waite

2008-01-01

275

Vascular aquatic plants for mineral nutrient removal from polluted waters  

Microsoft Academic Search

Aquatic plants have potential as feedstuffs in certain nations, but the economics of harvesting and processing would prohibit\\u000a their direct utilization as a forage in technologically advanced nations. However, nutrient pollution is accelerating rates\\u000a of eutrophication of natural waters in many areas. Aquatic plants produce large standing crops and accumulate large amounts\\u000a of nutrients. Systems based on the harvest of

Claude E. Boyd

1970-01-01

276

European simplified boiling water reactor (ESBWR) plant  

SciTech Connect

This paper covers innovative ideas which made possible the redesign of the US 660-MW Simplified Boiling Water Reactor (SBWR) Reactor Island for a 1,200-MW size reactor while actually reducing the building cost. This was achieved by breaking down the Reactor Island into multiple buildings separating seismic-1 from non-seismic-1 areas, providing for better space utilization, shorter construction schedule, easier maintainability and better postaccident accessibility.

Posta, B.A.; Goldenberg, E.A.; Sawhney, P.S. [Bechtel Corp., San Francisco, CA (United States); Rao, A.S. [General Electric Nuclear Engineering, San Jose, CA (United States)

1996-07-01

277

Detailed modeling of the evaporation and thermal decomposition of urea-water-solution in SCR systems  

E-print Network

droplets (composed of water and zirconium acetate) axially injected into plasma. As water evaporates, the concentration of solute augments which leads to the formation of a precipitate shell. They studied the effects of droplet size, shell porosity and thickness and they shown different behaviors of droplet for different

Boyer, Edmond

278

[Plant growth with limited water]. Performance report  

SciTech Connect

When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

Not Available

1992-10-01

279

Water, plants, and early human habitats in eastern Africa.  

PubMed

Water and its influence on plants likely exerted strong adaptive pressures in human evolution. Understanding relationships among water, plants, and early humans is limited both by incomplete terrestrial records of environmental change and by indirect proxy data for water availability. Here we present a continuous record of stable hydrogen-isotope compositions (expressed as ?D values) for lipid biomarkers preserved in lake sediments from an early Pleistocene archaeological site in eastern Africa--Olduvai Gorge. We convert sedimentary leaf- and algal-lipid ?D values into estimates for ancient source-water ?D values by accounting for biochemical, physiological, and environmental influences on isotopic fractionation via published water-lipid enrichment factors for living plants, algae, and recent sediments. Reconstructed precipitation and lake-water ?D values, respectively, are consistent with modern isotopic hydrology and reveal that dramatic fluctuations in water availability accompanied ecosystem changes. Drier conditions, indicated by less negative ?D values, occur in association with stable carbon-isotopic evidence for open, C(4)-dominated grassland ecosystems. Wetter conditions, indicated by lower ?D values, are associated with expanded woody cover across the ancient landscape. Estimates for ancient precipitation amounts, based on reconstructed precipitation ?D values, range between approximately 250 and 700 mm · y(-1) and are consistent with modern precipitation data for eastern Africa. We conclude that freshwater availability exerted a substantial influence on eastern African ecosystems and, by extension, was central to early human proliferation during periods of rapid climate change. PMID:23267102

Magill, Clayton R; Ashley, Gail M; Freeman, Katherine H

2013-01-22

280

PHOTOREACTIVITY OF CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic matter (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organi...

281

WATER TREATMENT PLANT CONDITIONS Publication No._____________  

E-print Network

To my wife, Lauren, for her love and support. You are my best friend. Acknowledgements I would like to thank my wife Lauren, the love of my life, for her perpetual patience and support, keeping “Team Wahman ” moving towards our life goals. Thank you to my family, for their support over the years and knowing when to let me find my own way. Sometimes, the best support is to say nothing at all. I am grateful for funding provided by the American Water Works Association

David Gerard Wahman; Gerald E. Speitel; Lynn E. Katz; Desmond F. Lawler; Mary Jo Kirisits; David Gerard Wahman; David Gerard Wahman, Ph.D.

282

Water uptake in green roof microcosms: Effects of plant species and water availability  

Microsoft Academic Search

Green roofs are engineered ecosystems that rely on vegetation to provide services such as reduction of roof temperatures. Drought resistance is critical for plant survival on shallow-substrate green roofs, but potential trade-offs exist between water-use efficiency and ecosystem functions like transpirative cooling. Water loss from simulated green roof systems (microcosms) each containing 1 of 14 plant species belonging to 4

Derek Wolf; Jeremy T. Lundholm

2008-01-01

283

The analysis and composition of fatty material produced by the decomposition of herring in sea water  

USGS Publications Warehouse

This paper describes the analysis of calcium and magnesium salts of fatty acids derived from herring buried under sea water, and discusses some geochemical possibilities related to the origin of petroleum in sedimentary deposits.

Wells, R.C.; Erickson, E.T.

1933-01-01

284

Rationales for Multiple Stage Ozonation in Drinking Water Treatment Plants  

Microsoft Academic Search

Starting in the early 1970s, the application of ozone for drinking water treatment began to evolve from primarily single-purpose, single-stage use for disinfection, taste and odor control or iron and manganese oxidation, to multipurpose uses of ozone. As a result, most of the newer drinking water treatment plants have installed two- and even three-stages of ozonation. in order to maximize

Rip G. Rice

1987-01-01

285

Integrated operation of drinking water treatment plant at Amsterdam water supply  

Microsoft Academic Search

Water treatment plants are in general robust and designs are based on the performance of individual processes with pre-set boundary conditions. It is assumed that an integral approach of the entire treatment plant can lead to more efficient operation. Taking into account the developments in sensoring, automation and computation, it is a challenge to improve quality and reliability of the

G. J. Bosklopper; L. C. Rietveld; R. Babuska; B. Smaal; J. Timmer

286

Mathematics for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.  

ERIC Educational Resources Information Center

This booklet is intended to aid the prospective waste treatment plant operator or drinking water plant operator in learning to solve mathematical problems, which is necessary for Class I certification. It deals with the basic mathematics which a Class I operator may require in accomplishing day-to-day tasks. The book also progresses into problems…

South Dakota Dept. of Environmental Protection, Pierre.

287

A molecular dynamics study of model SI clathrate hydrates: the effect of guest size and guest-water interaction on decomposition kinetics.  

PubMed

One of the options suggested for methane recovery from natural gas hydrates is molecular replacement of methane by suitable guests like CO2 and N2. This approach has been found to be feasible through many experimental and molecular dynamics simulation studies. However, the long term stability of the resultant hydrate needs to be evaluated; the decomposition rate of these hydrates is expected to depend on the interaction between these guest and water molecules. In this work, molecular dynamics simulation has been performed to illustrate the effect of guest molecules with different sizes and interaction strengths with water on structure I (SI) hydrate decomposition and hence the stability. The van der Waals interaction between water of hydrate cages and guest molecules is defined by Lennard Jones potential parameters. A wide range of parameter spaces has been scanned by changing the guest molecules in the SI hydrate, which acts as a model gas for occupying the small and large cages of the SI hydrate. All atomistic simulation results show that the stability of the hydrate is sensitive to the size and interaction of the guest molecules with hydrate water. The increase in the interaction of guest molecules with water stabilizes the hydrate, which in turn shows a slower rate of hydrate decomposition. Similarly guest molecules with a reasonably small (similar to Helium) or large size increase the decomposition rate. The results were also analyzed by calculating the structural order parameter to understand the dynamics of crystal structure and correlated with the release rate of guest molecules from the solid hydrate phase. The results have been explained based on the calculation of potential energies felt by guest molecules in amorphous water, hydrate bulk and hydrate-water interface regions. PMID:25767053

Das, Subhadip; Baghel, Vikesh Singh; Roy, Sudip; Kumar, Rajnish

2015-04-14

288

Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues  

Microsoft Academic Search

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on

T. A. Kimmell; J. A. Veil

2009-01-01

289

SIMPLIFIED SIMULATION OF A BOILING WATER REACTOR POWER PLANT  

Microsoft Academic Search

Using analog computer facilities available at most iniversities, a ; boiling water reactor power plant was simulated in order to study for ; instructional purposes the system response to various deviations from normal ; operation conditions. The rather idealized model, which was similar to EBWR, was ; found to be quite stable and to behave qualitatively in a manner expected

R. E. George; A. Sesonske

1959-01-01

290

GE advanced boiling water reactors and plant systems design  

Microsoft Academic Search

The nuclear option is becoming increasingly important as the need for new baseload capacity and the environmental impact of burning fossil fuels becomes more evident. Advanced Light Water Reactor nuclear plants which are prelicensed and standardized are key to making nuclear energy an attractive option. GE Nuclear Energy has developed two new advanced and simplified BWR designs aimed at making

D. R. Wilkins; J. Chang

1992-01-01

291

Drinking Water Treatment Plant Design Incorporating Variability and Uncertainty  

Microsoft Academic Search

Both inherent natural variability and model parameter uncertainty must be considered in the development of robust and reliable designs for drinking water treatment. This study presents an optimization framework for investigating the effects of five variable influent parameters and three uncertain model parameters on the least-cost treatment plant configuration contact, direct, or nonsweep conventional filtration that reliably satisfies an effluent

Dominic L. Boccelli; Mitchell J. Small; Urmila M. Diwekar

2007-01-01

292

7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

293

Simulating Leaf Area of Corn Plants at Contrasting Water Status  

Technology Transfer Automated Retrieval System (TEKTRAN)

An exponential decay function was fitted with literature data to describe the decrease in leaf expansion rate as leaf water potential decreases. The fitted function was then applied to modify an existing leaf area simulation module in a soil-plant-atmosphere continuum model in order to simulate leaf...

294

Fetal loss and work in a waste water treatment plant  

Microsoft Academic Search

We investigated pregnancy outcomes in 101 wives of workers employed in a waste water treatment plant (WWTP), and verified fetal losses by hospital records. Paternal work histories were compiled and each of the 210 pregnancies was assigned a paternal exposure category. The relative risk of fetal loss was increased when paternal exposure to the WWTP occurred around the time of

R. W. Morgan; L. Kheifets; D. L. Obrinsky; M. D. Whorton; D. E. Foliart

1984-01-01

295

Application of fuzzy causal networks to waste water treatment plants  

Microsoft Academic Search

A graphical model, the extended fuzzy causal network is introduced and applied to a case study of waste water treatment plants. The structure of the network is developed using parameter sensitivity studies and the relationships between connected parameters are obtained using a learning approach adapted from fuzzy neural networks. The graphical model is shown to be able to translate the

Y. C. Huang; X. Z. Wang

1999-01-01

296

STRATEGIES FOR WATER AND WASTE REDUCTION IN DAIRY FOOD PLANTS  

EPA Science Inventory

A study was undertaken to reduce water and waste discharges in a complex, multiproduct dairy food plant through management control and modifications of equipment and processes. The objectives were to develop approaches that would be broadly applicable throughout the dairy industr...

297

Energy efficient water utilization systems in process plants  

Microsoft Academic Search

This paper introduces a new approach for the design of water utilization networks featuring minimum freshwater usage and minimum utility consumption in process plants. The procedure is confined to treat the single pollutant case, and it is based on a linear programming formulation that relies on necessary conditions of optimality and a heat transshipment model. An LP model is first

Miguel Bagajewicz; Hernán Rodera; Mariano Savelski

2002-01-01

298

Lowered water table level decreases boreal mire NECB - a question of increased decomposition or decreased photosynthesis?  

NASA Astrophysics Data System (ADS)

The fundamental prerequisite for development and maintenance of mire ecosystems is a positive water balance maintaining a water table level close to the soil surface. One potential effect of climate change at higher latitudes is decreased positive water balance, i.e. increased evapotranspiration and/or decreased precipitation during the growing season leading to a lowered water table level. A lowered water table level is well known to reduce both the net ecosystem exchange (NEE) and most likely also the Net Ecosystem Balance (NECB). Most commonly a reduced NEE is interpreted as resulting from increased respiration. Therefore, a water table draw down is often viewed as a severe threat to the large long-term carbon stores occurring in high latitude peatlands. We used eddy covariance derived data on NEE from a high latitude mire in Northern Sweden during a year with severe drought during the growing season to separate the effects between photosynthesis and ecosystem respiration. The long term annual average NEE at the site is ~59 g C m-2 yr-1 which during the year with summer drought was reduced to 17 g C m-2 yr-1 resulting in a NECB not different from zero. Detailed analyses of the diurnal variation in NEE as well as ordinary NEE-partitioning into gross photosynthesis and respiration respectively revealed a drastic decrease in daytime CO2 uptake while the nighttime CO2 emission hardly was affected at all. Thus, for this widespread type of mire the most significant direct effect of severe droughts is reduced photosynthesis rather then increased respiration.

Nilsson, Mats; Peichl, Matthias; Sagerfors, Jörgen; Ottosson-Lofvenius, Mikaell

2013-04-01

299

The rate of carbonic acid decomposition in sea water and its oceanographic significance  

E-print Network

with and without the influence of atmospheric carbon dioxide based upon Buch's tables on the carbon dioxide and boric acid system in sea water are compared with exper- imental data obtained by the method of Mitchell and Rakestraw(1933) and Stoddard (1952... Mixtures of weak acids and their salts or of weak bases and their sa3ts are called buffer solutions, since they resist a change in pH upon addit1on oi' sli~ht amounts oi' acid or bases (Kolthoff', 1949). Sea water contairs carbonic and boric acids...

Park, Kilho

1957-01-01

300

Plant rooting strategies in water-limited ecosystems  

NASA Astrophysics Data System (ADS)

Root depth and distribution are vital components of a plant's strategy for growth and survival in water-limited ecosystems and play significant roles in hydrologic and biogeochemical cycling. Knowledge of root profiles is invaluable in measuring and predicting ecosystem dynamics, yet data on root profiles are difficult to obtain. We developed an ecohydrological model of environmental forcing, soil moisture dynamics, and transpiration to explore dependencies of optimal rooting on edaphic, climatic, and physiological factors in water-limited ecosystems. The analysis considers individual plants with fixed biomass. Results of the optimization approach are consistent with profiles observed in nature. Optimal rooting was progressively deeper, moving from clay to loam, silt and then sand, and in wetter and cooler environments. Climates with the majority of the rainfall in winter produced deeper roots than if the rain fell in summer. Long and infrequent storms also favored deeper rooting. Plants that exhibit water stress at slight soil moisture deficiencies consistently showed deeper optimal root profiles. Silt generated the greatest sensitivity to differences in climatic and physiological parameters. The depth of rooting is governed by the depth to which water infiltrates, as influenced by soil properties and the timing and magnitude of water input and evaporative demand. These results provide a mechanistic illustration of the diversity of rooting strategies in nature.

Collins, D. B. G.; Bras, R. L.

2007-06-01

301

Improvement and Optimization of the A. H. Weeks Water Treatment Plant Processes, Windsor, ON, Canada  

Microsoft Academic Search

After the ozone system was implemented at the A.H.Weeks Water Treatment Plant in June 2001, the plant was monitored to evaluate the effects that ozone had on the plant operation and filtered water quality. Filter performance showed an improvement since ozone was applied. Longer filter run time and lower filtered water turbidity and particle count were achieved. Average treated water

Samar Mazloum; Saad Jasim; Nihar Biswas; Kerwin Rakness; Glenn Hunter

2004-01-01

302

Water Extraction from Coal-Fired Power Plant Flue Gas  

SciTech Connect

The overall objective of this program was to develop a liquid disiccant-based flue gas dehydration process technology to reduce water consumption in coal-fired power plants. The specific objective of the program was to generate sufficient subscale test data and conceptual commercial power plant evaluations to assess process feasibility and merits for commercialization. Currently, coal-fired power plants require access to water sources outside the power plant for several aspects of their operation in addition to steam cycle condensation and process cooling needs. At the present time, there is no practiced method of extracting the usually abundant water found in the power plant stack gas. This project demonstrated the feasibility and merits of a liquid desiccant-based process that can efficiently and economically remove water vapor from the flue gas of fossil fuel-fired power plants to be recycled for in-plant use or exported for clean water conservation. After an extensive literature review, a survey of the available physical and chemical property information on desiccants in conjunction with a weighting scheme developed for this application, three desiccants were selected and tested in a bench-scale system at the Energy and Environmental Research Center (EERC). System performance at the bench scale aided in determining which desiccant was best suited for further evaluation. The results of the bench-scale tests along with further review of the available property data for each of the desiccants resulted in the selection of calcium chloride as the desiccant for testing at the pilot-scale level. Two weeks of testing utilizing natural gas in Test Series I and coal in Test Series II for production of flue gas was conducted with the liquid desiccant dehumidification system (LDDS) designed and built for this study. In general, it was found that the LDDS operated well and could be placed in an automode in which the process would operate with no operator intervention or adjustment. Water produced from this process should require little processing for use, depending on the end application. Test Series II water quality was not as good as that obtained in Test Series I; however, this was believed to be due to a system upset that contaminated the product water system during Test Series II. The amount of water that can be recovered from flue gas with the LDDS is a function of several variables, including desiccant temperature, L/G in the absorber, flash drum pressure, liquid-gas contact method, and desiccant concentration. Corrosion will be an issue with the use of calcium chloride as expected but can be largely mitigated through proper material selection. Integration of the LDDS with either low-grade waste heat and or ground-source heating and cooling can affect the parasitic power draw the LDDS will have on a power plant. Depending on the amount of water to be removed from the flue gas, the system can be designed with no parasitic power draw on the power plant other than pumping loads. This can be accomplished in one scenario by taking advantage of the heat of absorption and the heat of vaporization to provide the necessary temperature changes in the desiccant with the flue gas and precipitates that may form and how to handle them. These questions must be addressed in subsequent testing before scale-up of the process can be confidently completed.

Bruce C. Folkedahl; Greg F. Weber; Michael E. Collings

2006-06-30

303

A thermochemical data bank for cycle analysis. [water decomposition for hydrogen production  

NASA Technical Reports Server (NTRS)

The use of the computer program PAC-2 to produce a thermodynamic data bank for various materials used in water-splitting cycles is described. The sources of raw data and a listing of 439 materials for which data are presently available are presented. This paper also discusses the use of the data bank in conjunction with two other programs, CEC-72 and HYDRGN. The integration of these three programs implement an evaluation procedure for thermochemical water splitting cycles. CEC-72 is a program used to predict the equilibrium composition of the various chemical reactions in the cycle. HYDRGN is a program which is used to calculate changes in thermodynamic properties, work of separation, amount of recycle, internal heat regeneration, total thermal energy and process thermal efficiency for a thermochemical cycle.

Carty, R.; Funk, J.; Conger, W.; Soliman, M.; Cox, K.

1976-01-01

304

Hydraulic redistribution may stimulate decomposition  

Microsoft Academic Search

Roots influence root litter decomposition through multiple belowground processes. Hydraulic lift or redistribution (HR) by\\u000a plants is one such process that creates diel drying–rewetting cycles in soil. However, it is unclear if this phenomenon influences\\u000a decomposition. Since decomposition in deserts is constrained by low soil moisture and is stimulated when dry soils are rewetted,\\u000a we hypothesized that diel drying–rewetting, via

Zachary T. Aanderud; James H. Richards

2009-01-01

305

[A field study of tundra plant litter decomposition rate via mass loss and carbon dioxide emission: the role of biotic and abiotic controls, biotope, season of year, and spatial-temporal scale].  

PubMed

Although many recently published original papers and reviews deal with plant matter decomposition rates and their controls, we are still very short in understanding of these processes in boreal and high latiude plant communities, especially in permafrost areas of our planet. First and foremost, this is holds true for winter period. Here, we present the results of 2-year field observations in south taiga and south shrub tundra ecosystems in European Russia. We pioneered in simultaneous application of two independent methods: classic mass loss estimation by litter-bag technique, and direct measurement of CO2 emission (respiration) of the same litter bags with different types of dead plant matter. Such an approach let us to reconstruct intra-seasonal dynamics of decomposition rates of the main tundra litter fractions with high temporal resolution, to estimate the partial role of different seasons and defragmentation in the process of plant matter decomposition, and to determine its factors under different temporal scale. PMID:25771676

Pochikalov, A V; Karelin, D V

2014-01-01

306

INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS  

SciTech Connect

This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system, which is powered by the waste heat from low pressure condensing steam in power plants. The desalination is driven by water vapor saturating dry air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. A thermodynamic analysis demonstrates that the DDD process can yield a fresh water production efficiency of 4.5% based on a feed water inlet temperature of only 50 C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day. The main focus of the initial development of the desalination process has been on the diffusion tower. A detailed mathematical model for the diffusion tower has been described, and its numerical implementation has been used to characterize its performance and provide guidance for design. The analysis has been used to design a laboratory scale diffusion tower, which has been thoroughly instrumented to allow detailed measurements of heat and mass transfer coefficient, as well as fresh water production efficiency. The experimental facility has been described in detail.

James F. Klausner; Renwei Mei; Yi Li; Mohamed Darwish; Diego Acevedo; Jessica Knight

2003-09-01

307

The plant multidrug resistance ABC transporter AtMRP5 is involved in guard cell hormonal signalling and water use  

E-print Network

of mrp5-1 in the light. Excised leaves of mutant plants exhibited reduced water loss, and water uptake was strongly decreased at the whole-plant level. Finally, if plants were not watered, mrp5-1 plants survived-1 plants have increased water use ef®ciency. Mutant plants overexpressing AtMRP5 under the control

Kuhlemeier, Cris

308

Water stress amelioration and plant growth promotion in wheat plants by osmotic stress tolerant bacteria.  

PubMed

Soil microorganisms with potential for alleviation of abiotic stresses in combination with plant growth promotion would be extremely useful tools in sustainable agriculture. To this end, the present study was initiated where forty-five salt tolerant bacterial isolates with ability to grow in high salt medium were obtained from the rhizosphere of Triticum aestivum and Imperata cylindrica. These bacteria were tested for plant-growth-promoting rhizobacteria traits in vitro such as phosphate solubilization, siderophore, ACC deaminase and IAA production. Of the forty-five isolates, W10 from wheat rhizosphere and IP8 from blady grass rhizosphere, which tested positive in all the tests were identified by morpholological, biochemical and 16SrDNA sequencing as Bacillus safensis and Ochrobactrum pseudogregnonense respectively and selected for in vivo studies. Both the bacteria could promote growth in six varieties of wheat tested in terms of increase in root and shoot biomass, height of plants, yield, as well as increase in chlorophyll content. Besides, the wheat plants could withstand water stress more efficiently in presence of the bacteria as indicated by delay in appearance of wilting symptoms increases in relative water content of treated water stressed plants in comparison to untreated stressed ones, and elevated antioxidant responses. Enhanced antioxidant responses were evident as elevated activities of enzymes such as catalase, peroxidase, ascorbate peroxidase, superoxide dismutase and glutathione reductase as well as increased accumulation of antioxidants such as carotenoids and ascorbate. Results clearly indicate that the ability of wheat plants to withstand water stress is enhanced by application of these bacteria which also function as plant growth promoting rhizobacteria. PMID:23239372

Chakraborty, U; Chakraborty, B N; Chakraborty, A P; Dey, P L

2013-05-01

309

Warm water aquaculture using waste heat and water from zero discharge power plants in the Great Basin  

SciTech Connect

Two series of experiments were completed to determine (a) toxicity of waste water from power plants on warm water fish and (b) multiple use of waste heat and water for aquatic animal and plant production. All three types of waste water from a typical coal-fired power plant are acceptable for growing catfish and tilapia following aeration. This growth was compared with fish raised in spring water. Closed, recirculating polyculture systems using evaporation pond water operated efficiently for plant (duckweed) and animal (fish and freshwater prawns) production. Duckweed is an excellent supplement for fish feed. Tilapia and freshwater prawns grew rapidly in the tanks containing duckweed only. 10 references, 13 tables.

Heckmann, R.A.; Winget, R.N.; Infanger, R.C.; Mickelsen, R.W.; Hendersen, J.M.

1984-01-31

310

Hydrogen production from water decomposition by redox of Fe 2O 3 modified with single- or double-metal additives  

NASA Astrophysics Data System (ADS)

Iron oxide modified with single- or double-metal additives (Cr, Ni, Zr, Ag, Mo, Mo-Cr, Mo-Ni, Mo-Zr and Mo-Ag), which can store and supply pure hydrogen by reduction of iron oxide with hydrogen and subsequent oxidation of reduced iron oxide with steam (Fe 3O 4 (initial Fe 2O 3)+4H 2?3Fe+4H 2O), were prepared by impregnation. Effects of various metal additives in the samples on hydrogen production were investigated by the above-repeated redox. All the samples with Mo additive exhibited a better redox performance than those without Mo, and the Mo-Zr additive in iron oxide was the best effective one enhancing hydrogen production from water decomposition. For Fe 2O 3-Mo-Zr, the average H 2 production temperature could be significantly decreased to 276 °C, the average H 2 formation rate could be increased to 360.9-461.1 ?mol min -1 Fe-g -1 at operating temperature of 300 °C and the average storage capacity was up to 4.73 wt% in four cycles, an amount close to the IEA target.

Liu, Xiaojie; Wang, Hui

2010-05-01

311

Changes in water quality in the Owabi water treatment plant in Ghana  

NASA Astrophysics Data System (ADS)

The study was conducted on the status of the quality of water from the Owabi water treatment plant that supplies drinking water to Kumasi, a major city in Ghana, to ascertain the change in quality of water from source to point-of-use. Physico-chemical, bacteriological water quality parameters and trace metal concentration of water samples from five different treatment points from the Owabi water treatment plant were investigated. The raw water was moderately hard with high turbidity and colour that exceeds the WHO guideline limits. Nutrient concentrations were of the following order: NH3 < NO2 - < NO3 - < PO4 3- < SO4 2- and were all below WHO permissible level for drinking water in all the samples at different stages of treatment. Trace metal concentrations of the reservoir were all below WHO limit except chromium (0.06 mg/L) and copper (0.24 mg/L). The bacteriological study showed that the raw water had total coliform (1,766 cfu/100 mL) and faecal coliform (257 cfu/100 mL) that exceeded the WHO standard limits, rendering it unsafe for domestic purposes without treatment. Colour showed strong positive correlation with turbidity (r = 0.730), TSS (r ? 0.922) and alkalinity (0.564) significant at p < 0.01. The quality of the treated water indicates that colour, turbidity, Cr and Cu levels reduced and fall within the WHO permissible limit for drinking water. Treatment process at the water treatment plant is adjudged to be good.

Akoto, Osei; Gyamfi, Opoku; Darko, Godfred; Barnes, Victor Rex

2014-09-01

312

Emergent plant decomposition and sedimentation: response to sediments varying in texture, phosphorus content and frequency of deposition  

Microsoft Academic Search

The impact of sedimentation on the decay of Typha latifolia, Typha angustifolia and Sparganium eurycarpum litter was evaluated in two Michigan wetlands. In one wetland, T. latifolia decay was studied among replicates of three treatments (unsedimented treatment, one-time sediment application (sandy loam) and multiple sediment applications). In the second wetland, decomposition of T. angustifolia and S. eurycarpum, exposed to phosphorus-enriched

Sharon M Vargo; Robert K Neely; Stephen M. Kirkwood

1998-01-01

313

INFLUENCE OF DECOMPOSITION ON CHEMICAL PROPERTIES OF PLANT-AND MANURE-DERIVED DISSOLVED ORGANIC MATTER AND SORPTION TO GOETHITE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sorption of dissolved organic matter (DOM) plays an important role in maintaining the fertility and quality of soils in agricultural ecosystems. Few studies have examined the effects of decomposition on DOM sorption and chemical characteristics. This study investigated the sorption to goethite of ...

314

Study on estimating the planting area of winter wheat based on mixed field decomposition of remote sensing  

Microsoft Academic Search

With the significantly improved data availability in remote sensing technology, mid-resolution images have become the primary data source for crop sown area measurement in large scale. However, it is still difficult to solve the problems of spectrum heterogeneity in one field and spectra similarity between fields. This paper developed mixed field decomposition method and tested the method in an urban

Xiaohe Gu; Jingcheng Zhanga; Yaozhong Panb; Tangao Hub; Le Lib; Chao Lib

2010-01-01

315

CHANGES IN MASS AND CHEMISTRY OF PLANT ROOTS DURING LONG-TERM DECOMPOSITION ON A CHIHUAHUAN DESERT WATERSHED  

EPA Science Inventory

We studied the spatial and temporal patterns of decomposition of roots of a desert sub-shrub, a herbaceous annual, and four species of perennial grasses at several locations on nitrogen fertilized and unfertilized transects on a Chihuahuan Desert watershed for 3.5 years. There we...

316

Significance of Plant Root Microorganisms in Reclaiming Water in CELSS  

NASA Technical Reports Server (NTRS)

Since many microorganisms demonstrate the ability to quickly break down complex mixtures of waste and environmental contaminants, examining their potential use for water recycling in a closed environment is appealing. Water contributes approximately 90 percent of the life sustaining provisions in a human space habitat. Nearly half of the daily water requirements will be used for personal hygiene and dish washing. The primary contaminants of the used "gray" water will be the cleansing agents or soaps used to carry out these functions. Reclaiming water from the gray water waste streams is one goal of the NASA program, Controlled Ecological Life Support Systems (CELSS). The microorganisms of plane roots are well documented to be of a beneficial effect to promote plant growth. Most plants exhibit a range of bacteria and fungi which can be highly plant-specific. In our investigations with lettuce grown in hydroponic culture, we identified a microflora of normal rhizosphere. When the roots were exposed to an anionic surfactant, the species diversity changed, based on morphological characteristics, with the numbers of species being reduced from 7 to 2 after 48 hours of exposure. In addition, the species that became dominant in the presence of the anionic surfactant also demonstrated a dramatic increase in population density which corresponded to the degradation of the surfactant in the root zone. The potential for using these or other rhizosphere bacteria as a primary or secondary waste processor is promising, but a number of issues still warrant investigation; these include but are not limited to: (1) the full identification of the microbes, (2) the classes of surfactants the microbes will degrade, (3) the environmental conditions required for optimal processing efficiency and (4) the ability of transferring the microbes to a non-living solid matrix such as a bioreactor.

Bubenheim, David L.; Greene, Catherine; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

1996-01-01

317

INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS  

SciTech Connect

An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

2004-09-01

318

Nitrogen Removal from Eutrophicated Water by Aquatic Plants  

Microsoft Academic Search

\\u000a Increased N concentration in an aquatic ecosystem is one of important causes of eutrophication. Aquatic higher plants in eutrophic\\u000a water bodies can remove N by direct uptake and by being a carbon source and a surface substrate for microorganisms and algae,\\u000a which also use N as a nutrient and can transform N into gaseous forms that escape from the ecosystem.

Olga Babourina; Zed Rengel

319

Enhanced decomposition of 1,4-dioxane in water by ozonation under alkaline condition.  

PubMed

1,4-Dioxane is a probable human carcinogenic and refractory substance that is widely detected in aquatic environments. Traditional wastewater treatment processes, including activated sludge, cannot remove 1,4-dioxane. Removing 1,4-dioxane with a reaction kinetic constant of 0.32 L/(mol·s) by using ozone, a strong oxidant, is difficult. However, under alkaline environment, ozone generates a hydroxyl radical (•OH) that exhibits strong oxidative potential. Thus, the ozonation of 1,4-dioxane in water under different pH conditions was investigated in this study. In neutral solution, with an inlet ozone feed rate of 0.19 mmol/(L·min), the removal efficiency of 1,4-dioxane was 7.6% at 0.5 h, whereas that in alkaline solution was higher (16.3-94.5%) within a pH range of 9-12. However, the removal efficiency of dissolved organic carbon was considerably lower than that of 1,4-dioxane. This result indicates that several persistent intermediates were generated during 1,4-dioxane ozonation. The pseudo first-order reaction further depicted the reaction of 1,4-dioxane. The obvious kinetic constants (kobs) at pH 9, 10, 11 and 12 were 0.94, 2.41, 24.88 and 2610 L/(mol·s), respectively. Scavenger experiments on radical species indicated that •OH played a key role in removing 1,4-dioxane during ozonation under alkaline condition. PMID:25521127

Tian, Gui-Peng; Wu, Qian-Yuan; Li, Ang; Wang, Wen-Long; Hu, Hong-Ying

2014-01-01

320

Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant  

PubMed Central

Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.

Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

2015-01-01

321

ARSENIC REMOVAL FROM DRINKING WATER BY COAGULATION/FILTRATION AND LIME SOFTENING PLANTS  

EPA Science Inventory

This report documents a long term performance (one year) study of 3 water treatment plants to remove arsenic from drinking water sources. The 3 plants consisted of 2 conventional coagulation/filtration plants and 1 lime softening plant. The study involved the collecting of weekly...

322

CHEMICAL COMPOSITION OF CROP BIOMASS IMPACTS ITS DECOMPOSITION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Understanding the interaction between plant components and their subsequent decomposition provides insights on how plant quality differences may influence carbon (C) sequestration within a given management system. Our hypothesis was that decomposition is a function of biochemical composition when al...

323

Application of 2D-Nonlinear Shallow Water Model of Tsunami by using Adomian Decomposition Method  

SciTech Connect

One of the most important questions in tsunami modeling is the estimation of tsunami run-up heights at different points along a coastline. Methods for numerical simulation of tsunami wave propagation in deep and shallow seas are well developed and have been widely used by many scientists (2001-2008). In this paper, we consider a two-dimensional nonlinear shallow water model of tsunami given by Tivon Jacobson is work [1]. u{sub t}+uu{sub x}+{nu}u{sub y} -c{sup 2}(h{sub x}+(h{sub b}){sub x}) {nu}{sub t}+u{nu}{sub x}+{nu}{nu}{sub y} = -c{sup 2}(h{sub y}+(h{sub b}){sub y}) h{sub t}+(hu){sub x}+(h{nu}){sub y} = 0 g-shore, h is surface elevation and s, t is time, u is velocity of cross-shore, {nu} is velocity of along-shore, h is surface elevation and h{sub b} is function of shore. This is a nondimensionalized model with the gravity g and constant reference depth H factored into c = {radical}(gH). We apply the Adomian Decompostion Method (ADM) to solve the tsunami model. This powerful method has been used to obtain explicit and numerical solutions of three types of diffusion-convection-reaction (DECR) equations. The ADM results for the tsunami model yield analytical solutions in terms of a rapidly convergent infinite power series. Symbolic computation, numerical results and graphs of solutions are obtained by Maple program.

Waewcharoen, Sribudh; Boonyapibanwong, Supachai; Koonprasert, Sanoe [Department of Mathematics, King Mongkut's University of Technology, North Bangkok (Thailand)

2008-09-01

324

Soil Water Sensor Needs for the Evaluation of Hydraulic Lift in Crop Plants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hydraulic lift (HL) in plants is defined as the process by which water is redistributed from wet soil zones to drier soil zones through the plant root system in response to gradients in water potential. Water is released into the dry soil when plant transpiration is low (night) and reabsorbed by th...

325

An ASAE/CSAE Meeting Presentation Paper Number: 043065 Estimating Water Stress in Plants Using  

E-print Network

An ASAE/CSAE Meeting Presentation Paper Number: 043065 Estimating Water Stress in Plants Using 2004 Abstract. The ability to estimate plant water content may provide valuable information plant species (corn, spinach and snap beans) grown in a greenhouse and subjected to different watering

Jones, Carol

326

Innovative Fresh Water Production Process for Fossil Fuel Plants  

SciTech Connect

This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A dynamic analysis of heat and mass transfer demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3 Hg. The optimum operating condition for the DDD process with a high temperature of 50 C and sink temperature of 25 C has an air mass flux of 1.5 kg/m{sup 2}-s, air to feed water mass flow ratio of 1 in the diffusion tower, and a fresh water to air mass flow ratio of 2 in the condenser. Operating at these conditions yields a fresh water production efficiency (m{sub fW}/m{sub L}) of 0.031 and electric energy consumption rate of 0.0023 kW-hr/kg{sub fW}. Throughout the past year, the main focus of the desalination process has been on the direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. The analyses agree quite well with the current data. Recently, it has been recognized that the fresh water production efficiency can be significantly enhanced with air heating. This type of configuration is well suited for power plants utilizing air-cooled condensers. The experimental DDD facility has been modified with an air heating section, and temperature and humidity data have been collected over a range of flow and thermal conditions. It has been experimentally observed that the fresh water production rate is enhanced when air is heated prior to entering the diffusion tower. Further analytical analysis is required to predict the thermal and mass transport with the air heating configuration.

James F. Klausner; Renwei Mei; Yi Li; Jessica Knight; Venugopal Jogi

2005-09-01

327

Mixing effects of understory plant litter on decomposition and nutrient release of tree litter in two plantations in Northeast China.  

PubMed

Understory vegetation plays a crucial role in carbon and nutrient cycling in forest ecosystems; however, it is not clear how understory species affect tree litter decomposition and nutrient dynamics. In this study, we examined the impacts of understory litter on the decomposition and nutrient release of tree litter both in a pine (Pinus sylvestris var. mongolica) and a poplar (Populus × xiaozhuanica) plantation in Northeast China. Leaf litter of tree species, and senesced aboveground materials from two dominant understory species, Artemisia scoparia and Setaria viridis in the pine stand and Elymus villifer and A. sieversiana in the poplar stand, were collected. Mass loss and N and P fluxes of single-species litter and three-species mixtures in each of the two forests were quantified. Data from single-species litterbags were used to generate predicted mass loss and N and P fluxes for the mixed-species litterbags. In the mixture from the pine stand, the observed mass loss and N release did not differ from the predicted value, whereas the observed P release was greater than the predicted value. However, the presence of understory litter decelerated the mass loss and did not affect N and P releases from the pine litter. In the poplar stand, litter mixture presented a positive non-additive effect on litter mass loss and P release, but an addition effect on N release. The presence of understory species accelerated only N release of poplar litter. Moreover, the responses of mass loss and N and P releases of understory litter in the mixtures varied with species in both pine and poplar plantations. Our results suggest that the effects of understory species on tree litter decomposition vary with tree species, and also highlight the importance of understory species in litter decomposition and nutrient cycles in forest ecosystems. PMID:24143184

Zhao, Lei; Hu, Ya-Lin; Lin, Gui-Gang; Gao, Yong-chao; Fang, Yun-Ting; Zeng, De-Hui

2013-01-01

328

Mixing Effects of Understory Plant Litter on Decomposition and Nutrient Release of Tree Litter in Two Plantations in Northeast China  

PubMed Central

Understory vegetation plays a crucial role in carbon and nutrient cycling in forest ecosystems; however, it is not clear how understory species affect tree litter decomposition and nutrient dynamics. In this study, we examined the impacts of understory litter on the decomposition and nutrient release of tree litter both in a pine (Pinus sylvestris var. mongolica) and a poplar (Populus × xiaozhuanica) plantation in Northeast China. Leaf litter of tree species, and senesced aboveground materials from two dominant understory species, Artemisia scoparia and Setaria viridis in the pine stand and Elymus villifer and A. sieversiana in the poplar stand, were collected. Mass loss and N and P fluxes of single-species litter and three-species mixtures in each of the two forests were quantified. Data from single-species litterbags were used to generate predicted mass loss and N and P fluxes for the mixed-species litterbags. In the mixture from the pine stand, the observed mass loss and N release did not differ from the predicted value, whereas the observed P release was greater than the predicted value. However, the presence of understory litter decelerated the mass loss and did not affect N and P releases from the pine litter. In the poplar stand, litter mixture presented a positive non-additive effect on litter mass loss and P release, but an addition effect on N release. The presence of understory species accelerated only N release of poplar litter. Moreover, the responses of mass loss and N and P releases of understory litter in the mixtures varied with species in both pine and poplar plantations. Our results suggest that the effects of understory species on tree litter decomposition vary with tree species, and also highlight the importance of understory species in litter decomposition and nutrient cycles in forest ecosystems. PMID:24143184

Zhao, Lei; Hu, Ya-Lin; Lin, Gui-Gang; Gao, Yong-chao; Fang, Yun-Ting; Zeng, De-Hui

2013-01-01

329

Stable isotopes in plant physiology: using water isotopes to study water fluxes in a temperate forest  

NASA Astrophysics Data System (ADS)

Drought has profound consequences on vegetation, including decreases in instantaneous carbon uptake; damage that limits future uptake for the life of the plant; mortality that can lead to large sources of carbon to the atmosphere; and shifts in biogeography that alter future potential for carbon uptake and capacitance. These processes are largely absent from global models, for lack of understanding in how co-occurring plants compete for water, weak understanding of how plant hydraulics is coordinated to minimize risk of drought, and few empirical data to constrain superior models of these processes. Here we present the results of a large-scale field experiment at Silas Little Experimental Forest (NJ), where rainwater was diverted from a 10m^2 area around selected trees from two different species (either oak or pine trees) and either re-injected (control plots), discarded (drought plots) or replaced by isotopically labeled water (isotope plots). We sampled heavily the drought plots and collected valuable information on tree hydraulics under drought conditions, such as water potentials of soil, leaf and stem, photosynthetic rate or sap flow. At the isotope plots, we followed the injected water within the injection trees and the surrounding ones. In particular, using an innovative setup for in-situ measurement paired with a laser spectrometer, we studied the isotopes effects within the tree xylem, which gave us a better understanding of water uptake by the roots and its transport to the leaves. By tracking the labeled water in the surrounding trees, we were also able to quantify the importance of plant competition for water availability below ground. We show here the importance of understanding all the phases of the water transport in the biosphere to help constraining climate models.

Gerlein, C.; Wolf, A.; Caylor, K. K.

2013-12-01

330

Spatial and temporal variability of soil water in drylands: plant water potential as a diagnostic tool  

Microsoft Academic Search

Arid and semi-arid regions are characterized by low rainfall and high potential evaporative demand. Here, water is the major\\u000a limiting factor for plant growth and productivity. Soil and surface hydrology properties (e.g. field capacity, infiltration\\u000a rates) effectively control the water re-distribution in the ecosystem, a fact that is aggravated in arid environments. Information\\u000a of the spatial and temporal accessibility of

Maik Veste; Markus Staudinger; Manfred Küppers

2008-01-01

331

LU Decomposition  

NSDL National Science Digital Library

Created by Stephanie Fitchett and David Smith for the Connected Curriculum Project, the purpose of this module is to examine LU decompositions of matrices and to see how an LU decomposition can improve computational efficiency in solving matrix equations. This is part of a larger collection of learning modules hosted by Duke University.

Fitchett, Stephanie

332

Passive cooling means for water cooled nuclear reactor plants  

SciTech Connect

This patent describes a water cooled, nuclear fission reactor plant having an improved auxiliary passive cooling system for dissipating heat produced during periods of other than normal operation, the nuclear fission reactor plant. It comprises the combination of: a reactor pressure vessel containing a core of heat producing fissionable fuel material provided with reciprocally removable fission control rods and having external steam and hot coolant water conduits extending out therefrom including a circulation loop passing through a heat exchanger comprising a steam driven turbine, the reactor pressure vessel and adjacent components being housed within an enclosing, substantially gas impermeable containment structure for retaining a gaseous atmosphere enveloping the reactor pressure vessel and adjacent components; a container retaining a pool of cooling water isolated from the atmosphere of the containment structure and positioned at a level within the containment structure above the reactor pressure vessel, the isolation container including a heat exchanger unit submerged in the retained pool of cooling water having an inlet which is in optional fluid communication with the interior of the reactor pressure vessel and with the atmosphere of the containment structure enveloping the pressure vessel; a suppression pool chamber containing a pool of cooling water for condensing steam positioned adjacent to the reactor pressure vessel and having a horizontal vent passing to an adjoining area which is in open communication to the atmosphere of the containment structure; a vent duct extending from an outlet of the heat exchanger unit submerged in the isolation container pool downward into the suppression pool chamber with its open end terminating below the surface of the cooling water pool and above the level of the horizontal vent passing an adjoining area.

Gluntz, D.M.; Oosterkamp, W.J.; van Kuijk, R.M.

1992-04-07

333

Introduction to Chemistry for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.  

ERIC Educational Resources Information Center

Presented are basic concepts of chemistry necessary for operators who manage drinking water treatment plants and wastewater facilities. It includes discussions of chemical terms and concepts, laboratory procedures for basic analyses of interest to operators, and discussions of appropriate chemical calculations. Exercises are included and answer…

South Dakota Dept. of Environmental Protection, Pierre.

334

Integrated optimization of a waste water treatment plant using statistical analysis  

Microsoft Academic Search

In this research, a waste water treatment plant is systematically optimized. The waste water treatment plant is used to remove aluminium from waste water using precipitation, flocculation and flotation. In total 40 variables influence the combined unit. After systematic selection, the number of variables was reduced to six: the waste water flow, pH, agitation velocity, amount of poly-electrolyte, amount of

Frank Halters; Edwin Zondervan; Andre de Haan

2010-01-01

335

Comprehensive cooling water study: Volume 2, Water quality, Savannah River Plant: Final report  

SciTech Connect

The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The first is a summary of environmental effects. The other seven volumes address water quality, radionuclide and heavy metal transport, wetlands, aquatic ecology, Federally endangered species, ecology of Par Pond, and waterfowl. 60 figs., 70 tabs.

Lower, M.W. (ed.)

1987-10-01

336

The impact of water use fees on dispatching and water requirements for water-cooled power plants in Texas.  

PubMed

We utilize a unit commitment and dispatch model to estimate how water use fees on power generators would affect dispatching and water requirements by the power sector in the Electric Reliability Council of Texas' (ERCOT) electric grid. Fees ranging from 10 to 1000 USD per acre-foot were separately applied to water withdrawals and consumption. Fees were chosen to be comparable in cost to a range of water supply projects proposed in the Texas Water Development Board's State Water Plan to meet demand through 2050. We found that these fees can reduce water withdrawals and consumption for cooling thermoelectric power plants in ERCOT by as much as 75% and 23%, respectively. To achieve these water savings, wholesale electricity generation costs might increase as much as 120% based on 2011 fuel costs and generation characteristics. We estimate that water saved through these fees is not as cost-effective as conventional long-term water supply projects. However, the electric grid offers short-term flexibility that conventional water supply projects do not. Furthermore, this manuscript discusses conditions under which the grid could be effective at "supplying" water, particularly during emergency drought conditions, by changing its operational conditions. PMID:24832169

Sanders, Kelly T; Blackhurst, Michael F; King, Carey W; Webber, Michael E

2014-06-17

337

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2011 CFR

18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2011-04-01

338

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2010 CFR

18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2010-04-01

339

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2014 CFR

18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2014-04-01

340

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2013 CFR

18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2013-04-01

341

18 CFR 420.51 - Hydroelectric power plant water use charges.  

Code of Federal Regulations, 2012 CFR

18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Hydroelectric power plant water use charges. 420.51 Section 420.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN...

2012-04-01

342

Removal of fluoride from water by five submerged plants.  

PubMed

Studies were conducted on the bioconcentration of fluoride (F(-)) in five submerged plants species. Ceratophyllum demersum, Hydrilla verticillata, Potamogeton malaianus, Myriophyllum verticillatum and Elodea nuttallii were all able to remove F(-) from water to some degree of efficiencies. At 5-20 mg F(-)/L culture solution, C. demersum had the best F(-)-removal performance, E. nuttallii had the poorest F(-)-removal performance among these plants. The relative growth rate (RGR) of the five species varied in different concentrations of F(-), of which C. demersum had the highest RGR. Its RGR decreased by 26.3 %, 63.2 % and 73.7 % from controls at 5, 10 and 20 mg F/L, respectively. PMID:22722597

Zhou, Jun; Gao, Jingqing; Liu, Yang; Ba, Kun; Chen, Shaohua; Zhang, Rinqin

2012-08-01

343

Functional Differences in Soil Water Pools: a New Perspective on Plant Water Use in Water-Limited Ecosystems  

Microsoft Academic Search

\\u000a Arid and semi-arid ecosystems cover roughly half of the earth's surface. Significant changes in vegetation cover combined\\u000a with climate change have increased concern over the future of these lands, which have considerable economic importance. Much\\u000a research has focused on plant—soil water relations in these systems, yet many mechanisms and significance of water use patterns\\u000a are not well under-stood. Here we

Ronald J. Ryel; Carolyn Y. Ivans; Michael S. Peek; A. Joshua Leffler

344

Relationships between plant and soil water status in vine ( Vitis vinifera L.)  

Microsoft Academic Search

Soil water status and its effect on plant water status are commonly evaluated for water stress diagnosis in annual crops.\\u000a We investigated the application of this method to vineyards, using the fraction of transpirable soil water (FTSW) to characterise\\u000a the soil water deficit experienced by the plant. The stability of the relationship between FTSW and predawn leaf water potential\\u000a (?p)

A. Pellegrino; E. Lebon; M. Voltz; J. Wery

2005-01-01

345

Numerical simulation of the thermal conditions in a sea bay water area used for water supply to nuclear power plants  

SciTech Connect

Consideration is given to the numerical simulation of the thermal conditions in sea water areas used for both water supply to and dissipation of low-grade heat from a nuclear power plant on the shore of a sea bay.

Sokolov, A. S. [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)] [JSC 'B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG)' (Russian Federation)

2013-07-15

346

Has the plant genetic variability any role in models of water transfer in the soil-plant-atmosphere continuum ?  

NASA Astrophysics Data System (ADS)

Water transfer in the SPAC is essentially linked to environmental conditions such as evaporative demand or soil water potential, and physical parameters such as soil hydraulic capacity or hydraulic conductivity. Models used in soil science most often represent the plant via a small number of variables such as the water flux that crosses the base of the stem or the root length (or area) in each soil layer. Because there is an increasing demand for computer simulations of plants that would perform better under water deficit, models of SPA water transfer are needed that could better take into account the genetic variability of traits involved in plant hydraulics. (i) The water flux through the plant is essentially limited by stomata, which present a much higher resistance to water flow than those in the soil - root continuum. This can lead to unexpected relations between flux, leaf water potential and root hydraulic conductance. (ii) A large genetic variability exists within and between species for stomatal control, with important consequences for the minimum soil water potential that is accessible to the plant. In particular, isohydric plants that maintain leaf water potential in a narrow range via stomatal control have a higher (nearer to 0) 'wilting point' than anisohydric plants that allow leaf water potential to reach very low values. (iii) The conductivity for water transfer in roots and shoots is controlled by plants via aquaporins. It largely varies with time of the day, water and nutrient status, in particular via plant hormones and circadian rhythms. Models of SPA water transfer with a time definition of minutes to hour should probably not ignore this, while those with longer time steps are probably less sensitive to changes in plant hydraulic conductivity. (iv) The "dogma" that dense root systems provide tolerance to water deficit is profoundly affected when the balance "H2O gain vs C investment" is taken into account. At least three programmes of recurrent selection for drought tolerance have resulted in a decrease in root biomass. Overall, it is now crucial to take into account the rapid progress in plant hydraulics in SPA models of water transfer. Several projects aim at this objective, in particular the EU project DROPS that gathers geneticists, plant modellers and soil modellers.

Tardieu, F.

2012-04-01

347

Purification of fuel and nitrate contaminated ground water using a free water surface constructed wetland plant  

SciTech Connect

Contaminated ground water from a former coke plant site was purified in a free water surface (FWS) constructed wetland plant during a 3-mo short-term experiment. The pilot plant (total surface area 27 m{sup 2}) was filled with a 1 m thick lava-gravel substrate planted with cattail (Typha spp.) and bulrush (Scirpus lacustrls). Major contaminants were low to moderate concentrations of polycyclic aromatic hydrocarbons, BTEX, nitrate, and nitrite. The wetland was dosed at hydraulic loading rates of q{sub A} = 4.8 and 9.6 cm d{sup {minus}1} with a hydraulic residence time (HRT) of 13.7 and 6.8 d. The surface removal rates of PAH were between 98.8 and 1914 mg m{sup {minus}2} d{sup {minus}1}. Efficiency was always {gt}99%. Extraction of lava gravel showed that approx. 0.4% of the applied PAH were retained on the substratum. The ratio of {Sigma}2,3-ring PAH and {Sigma}4,5,6-ring PAH showed a shift from 1:0.11 in water to 1:2.5 in lava. The removal of BTEX was {gt}99%, but might be in part due to volatilization. The efficiency in the removal of nitrate was 91% and of nitrite was 97%. Purification performance was not influenced by hydraulic loading rates or after die-back of the macrophytes.

Machate, T.; Heuermann, E.; Schramm, K.W.; Kettrup, A.

1999-10-01

348

Stable Carbon Isotopes As Indicators of Plant Water Use Efficiency  

NASA Astrophysics Data System (ADS)

Stable carbon isotopes have been utilized to better understand how environmental variables influence the efficiency of photosynthesis, specifically what factors limit the uptake and absorption of CO2 during photosynthesis. An understanding of the controls over both gas exchange and stomatal conductance can provide an explanation for the possible environmental influences on plant WUE. The ?13C of extractive-free wood was used as an index of plant water use efficiency at Mica Creek Experimental Watershed, Shoshone County, ID. The ?13C values of tree rings were used to determine the effects of clear cut and partial cut harvesting practices, the effect of elevation, and species differences in intrinsic water use efficiency (WUE) among coniferous species including: Thuja plicata, Larix occidentalis, Picea engelmannii, Pseudotsuga menziesii, Abies lasiocarpa, and Abies grandis. We found significant effects of harvest treatments (p=0.0197), elevation (p= 0.0268), and species (p<0.001) on tree ?13C. The significantly more enriched isotopic signatures observed in Thuja plicata (?13C = -23.37 ±0.17‰), indicate that it is a more water use efficient species compared to Larix occidentalis (?13C = -25.66 ±0.43‰), and Abies grandis (?13C = -25.83 ±0.15‰). There was also an overall trend of ?13C enrichment with elevation. The isotopic composition of tree rings has been estimated to increase by 0.003 ‰ per meter of elevation gain, which may be related to a decrease in soil moisture with elevation. Finally, the mean ?13C values observed on partial cut (?13C = -24.73 ±0.10‰) and clear cut treatments (?13C = -24.45 ±0.29‰) were significantly more enriched than the mean value for the control treatment (?13C = -25.25 ±0.19‰). The more enriched isotopic signatures observed on the harvested treatments indicate that the trees are more water use efficient, which may be a result of increased photosynthetic capacity with an increase in the availability of water, foliar nitrogen, and light to individual trees on the harvested treatments. The reduction of stand density through harvesting may reduce the transpirational water losses on a stand level, thus increasing the water availability for individual trees.

Powers, E. M.; Marshall, J. D.; Ubierna Lopez, N.

2007-12-01

349

A partition-limited model for the plant uptake of organic contaminants from soil and water  

USGS Publications Warehouse

In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plant water and soil interstitial water, ??pt (??? 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of ??pt in several published crop-contamination studies, including near-equilibrium values (i.e., ??pt ??? 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.

Chiou, C.T.; Sheng, G.; Manes, M.

2001-01-01

350

Effects of livestock watering sites on alien and native plants in the Mojave Desert, USA  

USGS Publications Warehouse

Increased livestock densities near artificial watering sites create disturbance gradients called piospheres. We studied responses of alien and native annual plants and native perennial plants within 9 piospheres in the Mojave Desert of North America. Absolute and proportional cover of alien annual plants increased with proximity to watering sites, whereas cover and species richness of native annual plants decreased. Not all alien species responded the same, as the alien forb Erodium cicutarium and the alien grass Schismus spp. increased with proximity to watering sites, and the alien annual grass Bromus madritensis ssp. rubens decreased. Perennial plant cover and species richness also declined with proximity to watering sites, as did the structural diversity of perennial plant cover classes. Significant effects were focused within 200 m of the watering sites, suggesting that control efforts for alien annual plants and restoration efforts for native plants should optimally be focused within this central part of the piosphere gradient.

Brooks, M.L.; Matchett, J.R.; Berry, K.H.

2006-01-01

351

Mitigation of microbial corrosion in Ras Budran water injection plant  

SciTech Connect

The Oil Company is water flooding Ras Budran field with Gulf of Suez water as a secondary means of oil recovery. Mitigation of microbial corrosion in Ras Budran water treatment plant is achieved by the continuous chlorination and weekly slugging of two types of biocides alternatively. Three years from commissioning, water quality started deteriorating at the offshore platforms in terms of high H{sub 2}S, iron contents, counts and corrosion rates. The main cause was attributed to the adhering property of sessile sulphate reducing bacteria (SRB) that could neither be controlled by corrosion inhibitor nor biocide treatment. In accordance, a cleaning and sterilization program was established for the piggable section of the sub sea injection line. This paper also presents the recent failure experienced in the remaining unpiggable section of the injection line. Diagnosis and analysis revealed that microbial corrosion was the main contributor to the failure due to the lack of pigging facility and the inability of removing the complex biofilms in which sessile bacteria grow, and rendering the applied biocides ineffective. For further confirmation intelligent pigging of the intact pipeline was run. Results showed that the line is in good condition internally with no significant corrosion.

Khattab, N.M. [Suez Oil Co., Cairo (Egypt)

1995-12-01

352

Estimating plant available water content from remotely sensed evapotranspiration  

NASA Astrophysics Data System (ADS)

Plant available water content (PAWC) is an emergent soil property that is a critical variable in hydrological modelling. PAWC determines the active soil water storage and, in water-limited environments, is the main cause of different ecohydrological behaviour between (deep-rooted) perennial vegetation and (shallow-rooted) seasonal vegetation. Conventionally, PAWC is estimated for a combination of soil and vegetation from three variables: maximum rooting depth and the volumetric water content at field capacity and permanent wilting point, respectively. Without elaborate local field observation, large uncertainties in PAWC occur due to the assumptions associated with each of the three variables. We developed an alternative, observation-based method to estimate PAWC from precipitation observations and CSIRO MODIS Reflectance-based Evapotranspiration (CMRSET) estimates. Processing steps include (1) removing residual systematic bias in the CMRSET estimates, (2) making spatially appropriate assumptions about local water inputs and surface runoff losses, (3) using mean seasonal patterns in precipitation and CMRSET to estimate the seasonal pattern in soil water storage changes, (4) from these, calculating the mean seasonal storage range, which can be treated as an estimate of PAWC. We evaluate the resulting PAWC estimates against those determined in field experiments for 180 sites across Australia. We show that the method produces better estimates of PAWC than conventional techniques. In addition, the method provides detailed information with full continental coverage at moderate resolution (250 m) scale. The resulting maps can be used to identify likely groundwater dependent ecosystems and to derive PAWC distributions for each combination of soil and vegetation type.

van Dijk, A. I. J. M.; Warren, G.; Doody, T.

2012-04-01

353

Capital cost functions of a surface water treatment plant and its components  

Microsoft Academic Search

The capital cost function of a surface water treatment plant has been estimated in a few past studies, of which the best known are a study by Orlob and Lindorf and another by Koenig. The present study presents an estimate of the capital cost function of a surface water treatment plant and estimates of the plant's major components which have

Hirohide Hinomoto

1977-01-01

354

Water and Plant Cells: Notes on a Teaching Scheme for O-Level.  

ERIC Educational Resources Information Center

Offers suggestions for teaching some aspects of water economy in plants. These include diffusion/osmosis, water transport, the part played by turgor in structural support, and its implications for plant organs or whole plants. Several practical demonstrations/experiments are also described. (JN)

Grenville, H. W.

1983-01-01

355

Decomposition of ozone in water in the presence of organic solutes acting as promoters and inhibitors of radical chain reactions  

Microsoft Academic Search

The decomposition of aqueous ozone is generally due to a chain reaction involving .OH radicals. Many organic solutes (impurities) can react with .OH to yield .Oâ⁻ upon addition of Oâ. .Oâ⁻ transfers its electron to a further ozone molecule in a rather selective reaction. The ozonide anion (.Oâ⁻) formed immediately decomposes into a further .OH radical. Compounds that convert .OH

Johannes Staehelin; Juerg Hoigne

1985-01-01

356

Rates of litter decomposition and soil respiration in relation to soil temperature and water in different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China.  

PubMed

To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010-Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m(-2) s(-1), and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%-45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling. PMID:25004164

Xiao, Wenfa; Ge, Xiaogai; Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

2014-01-01

357

Phase I: the pipeline-gas demonstration plant. Demonstration plant engineering and design. Volume 18. Plant Section 2700 - Waste Water Treatment  

SciTech Connect

Contract No. EF-77-C-01-2542 between Conoco Inc. and the US Department of Energy provides for the design, construction, and operation of a demonstration plant capable of processing bituminous caking coals into clean pipeline quality gas. The project is currently in the design phase (Phase I). This phase is scheduled to be completed in June 1981. One of the major efforts of Phase I is the process and project engineering design of the Demonstration Plant. The design has been completed and is being reported in 24 volumes. This is Volume 18 which reports the design of Plant Section 2700 - Waste Water Treatment. The objective of the Waste Water Treatment system is to collect and treat all plant liquid effluent streams. The system is designed to permit recycle and reuse of the treated waste water. Plant Section 2700 is composed of primary, secondary, and tertiary waste water treatment methods plus an evaporation system which eliminates liquid discharge from the plant. The Waste Water Treatment Section is designed to produce 130 pounds per hour of sludge that is buried in a landfill on the plant site. The evaporated water is condensed and provides a portion of the make-up water to Plant Section 2400 - Cooling Water.

none,

1981-05-01

358

Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.  

SciTech Connect

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in a subsequent study. For this study, the sources of cooling water used by the U.S. steam electric power plant fleet were examined. This effort entailed development of a database of power plants and cooling water intake locations and depths for those plants that use surface water as a source of cooling water. Development of the database and its general characteristics are described in Chapter 2 of this report. Examination of the database gives an indication of how low water levels can drop before cooling water intakes cease to function. Water level drops are evaluated against a number of different power plant characteristics, such as the nature of the water source (river vs. lake or reservoir) and type of plant (nuclear vs. fossil fuel). This is accomplished in Chapter 3. In Chapter 4, the nature of any compacts or agreements that give priority to users (i.e., which users must stop withdrawing water first) is examined. This is examined on a regional or watershed basis, specifically for western water rights, and also as a function of federal and state water management programs. Chapter 5 presents the findings and conclusions of this study. In addition to the above, a related intent of this study is to conduct preliminary modeling of how lowered surface water levels could affect generating capacity and other factors at different regional power plants. If utility managers are forced to take some units out of service or reduce plant outputs, the fuel mix at the remaining plants and the resulting carbon dioxide emissions may change. Electricity costs and other factors may also be impacted. Argonne has conducted some modeling based on the information presented in the database described in Chapter 2 of this report. A separate report of the modeling effort has been prepared (Poch et al. 2009). In addition to the U.S. steam electric power plant fleet, this modeling also includes an evaluation of power production of hydroelectric facilities. The focus of this modeling is on those power plants located in the western United States.

Kimmell, T. A.; Veil, J. A.; Environmental Science Division

2009-04-03

359

Decomposition techniques  

USGS Publications Warehouse

Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

Chao, T.T.; Sanzolone, R.F.

1992-01-01

360

Predawn disequilibrium between plant and soil water potentials in two cold-desert shrubs  

Microsoft Academic Search

Classical water relations theory predicts that predawn plant water potential should be in equilibrium with soil water potential\\u000a (soil ?w) around roots, and many interpretations of plant water status in natural populations are based on this expectation. We examined\\u000a this expectation for two salt-tolerant, cold-desert shrub species in glasshouse experiments where frequent watering assured\\u000a homogeneity in soil ?w and soil-root

L. A. Donovan; D. J. Grisé; J. B. West; R. A. Pappert; N. N. Alder; J. H. Richards

1999-01-01

361

Water Relations in Soils as Related to Plant Communities in Ruby Valley, Nevada  

Microsoft Academic Search

Distinct patterns of vegetation on ancient lake sediments in Ruby Valley, Nev., define differences in soil-water-plant relations resulting either from differences in depth to ground water or from differences in water-retention capacities of soils deriving water only from precipitation. In order of increasing depth to ground water, dominant plant species are Juncus balticus, Distichlis stricta, Potentilla fruticosa, Elymus cinereus, Sarcobatus

R. F. MILLER; F. A. BRANSON; I. S. MCQUEEN; C. T. SNYDER

362

Partitioning mycorrhizal influence on water relations of Phaseolus vulgaris into soil and plant components  

Microsoft Academic Search

There is growing appreciation of arbuscular mycorrhizal effects on soil properties and their potential conse- quences on plant behavior. We examined the possibility that mycorrhizal soil may directly influence plant water rela- tions. Using wild-type and noncolonizing bean mutants planted into soils previously produced using mycorrhizal or nonmycorrhizal sorghum plants, we partitioned mycorrhizal influence on stomatal conductance and drought resistance

Robert M. Augé; David M. Sylvia; Soon Park; Brian R. Buttery; Arnold M. Saxton; Jennifer L. Moore; Keunho Cho

2004-01-01

363

Studies on water-steam Rankine-cycle solar central receiver power plants. Final report  

Microsoft Academic Search

Cost estimates are provided for four 150 MWe solar hybrid central receiver power plants, based on the updating of conceptual designs developed in a previous EPRI solar hybrid power plant cost study, Water\\/Steam Rankine Cycle Solar Central Receiver Power Plant Cost Estimates. The power plants are hybrid in that main steam is generated in a central receiver and a conventional

J. R. Darnell; R. L. Lessley; J. A. Paffenbarger; A. A. Agur

1985-01-01

364

Natural selection on the plant-water relations of Cleome serrulata growing along natural moisture gradients  

Microsoft Academic Search

I investigated the extent and adaptive importance of genetically-based variation in plant water relations in two populations of the annual plant Cleome serrulata found growing along relatively short (Plant in May and June of 1984; differences up to 0.9 MPa were seen along the gradients. Seeds were collected from maternal plants growing along the moisture gradients and then grown under

M. A. Farris

1987-01-01

365

Volatilization of selenium from astragalus plants irrigated with selenium-laden water. Open file report  

Microsoft Academic Search

Living plants of Astragalus bisulcatus and Atriplex canescens were irrigated with solutions containing selenium to investigate the plants' ability to selectively remove selenium from selenium-contaminated water. The plants were grown from seed in an indoor environment and harvested for analysis at the end of a typical 7-month growing season. Of the total selenium applied to soil in which the plants

D. J. MacDonald; M. J. Lujan; T. S. Ary

1989-01-01

366

Application of artificial neural networks to the real time operation of water treatment plants  

Microsoft Academic Search

The water industry is facing increased pressure to produce higher quality treated water at a lower cost. The efficiency of a treatment process closely relates to the operation of the plant. To improve the operating performance, an artificial neural network (ANN) paradigm has been applied to a water treatment plant. An ANN which is able to learn the non-linear performance

A. Mirsepassi; B. Cathers; H. B. Dharmappa

1995-01-01

367

Recovery of alum from wasted sludge produced from water treatment plants  

Microsoft Academic Search

Alum is used in the coagulation of raw water in almost all water treatment plants world?wide. The sludge produced from this process is usually thrown away i.e. wasted. In Egypt, thousands of tons of alum are used annually in water treatment plants across the country costing millions of dollars. This paper deals with the recovery of most alum available at

M. S. E. Abdo; K. T. Ewida; Y. M. Youssef

1993-01-01

368

The effect of soil hydrology on the oxygen and hydrogen isotopic compositions of plants’ source water  

Microsoft Academic Search

Many studies have demonstrated that the isotopic composition of plants’ source water is the main factor affecting the isotopic composition of tree rings. Because of soil hydrological processes, soil water as the source water for plants may isotopically differ from precipitation that contains climatic information (such as surface temperature). This study addresses the effects of soil hydrological processes on the

Kuilian Tang; Xiahong Feng

2001-01-01

369

Developing Plans for Managing Invasive Aquatic Plants in Mississippi Water Resources  

Microsoft Academic Search

Invasive aquatic plants are an ever-growing nuisance to water resources in Mississippi and the rest of the United States. These plants are generally introduced from other parts of the world, some for beneficial or horticultural uses. Once introduced, they can interfere with navigation, impede water flow, increase flood risk, reduce hydropower generation, and increase evapotranspirational losses from surface waters. Invasive

John D. Madsen

370

Desert shrub water relations with respect to soil characteristics and plant functional type  

Microsoft Academic Search

Summary 1. Soil characteristics influence plant communities in part through water relations. Hypothetically, finer textured soils in arid climates should be associated with more negative plant and soil water potentials during drought, greater resistance of xylem to cavitation, and shallower root systems than coarse soils. 2. These hypotheses were tested by comparing the water relations of Great Basin shrubs growing

J. S. Sperry; U. G. Hacke

2002-01-01

371

Water Quality Improvements with the Use of Ozone at the Los Angeles Water Treatment Plant  

Microsoft Academic Search

At 600 mgd (2,270 ML\\/day), the recently completed Los Angeles Aqueduct Filtration Plant (LAAFP) is one of the world's largest water' treatment facilities utilizing ozone for pretreatment. The treatment process features direct filtration at rates of up to 13.5 gpm\\/ft (33 m\\/h). Under the optimized full-scale operation, preozonation has resulted in significantly reduced THM levels and very low effluent turbidity

Duane L. Georgeson; Ali A. Karimi

1988-01-01

372

A Case Study of the DAF-based Drinking Water Treatment Plant in Korea  

Microsoft Academic Search

Since 2003, a full-scale dissolved air flotation (DAF) process has been operated by the Korea Water Resources Corporation (K-Water) in the Songjeon drinking water treatment plant (SWTP). The SWPT was designed with an adaptable operation mode so that it is able to produce safe and stable drinking water, even when the raw water is in very poor condition. The adaptable

Byeong-Yong Sohn; Tae-Joon Park; Byung Soo Oh; Soon-Buhm Kwon; Joon-Wun Kang

2008-01-01

373

Small-scale Geothermal Power Plants Using Hot Spring Water  

NASA Astrophysics Data System (ADS)

The installed capacity of the geothermal power plants has been summed up to be about 515MW in Japan. However, the electricity generated by the geothermal resources only contributes to 0.2% of the whole electricity supply. After the catastrophic earthquake and tsunami devastated the Pacific coast of north-eastern Japan on Friday, March 11, 2011, the Japanese government is encouraging the increase of the renewable energy supply including the geothermal. It needs, however, more than 10 years to construct the geothermal power plant with more than 10MW capacity since the commencement of the development. Adding the problem of the long lead time, high temperature fluid is mainly observed in the national parks and the high quality of the geothermal resources is limited. On the other hand hot springs are often found. The utilisation of the low temperature hot water becomes worthy of notice. The low temperature hot water is traditionally used for bathing and there are many hot springs in Japan. Some of the springs have enough temperature and enthalpy to turn the geothermal turbine but a new technology of the binary power generation makes the lower temp fluid to generate electricity. Large power generators with the binary technology are already installed in many geothermal fields in the world. In the recent days small-scale geothermal binary generators with several tens to hundreds kW capacity are developed, which are originally used by the waste heat energy in an iron factory and so on. The newly developed binary unit is compact suitable for the installation in a Japanese inn but there are the restrictions for the temperature of the hot water and the working fluid. The binary power unit using alternatives for chlorofluorocarbon as the working fluid is relatively free from the restriction. KOBELCO, a company of the Kobe Steel Group, designed and developed the binary power unit with an alternative for chlorofluorocarbon. The unit has a 70 MW class electric generator. Three units have been installed in Obama Hot Spring area, Nagasaki Prefecture, where about 15,000 tonnes of hot water are produced in a day and more than 35% of the hot water flow directly to the sea. Another demonstration experiments are also conducted in several hot spring areas. In this study we will review several examples to utilise low temperature hot springs in Japan. Binary Power Unit at Obama (Fujino, 2013)

Tosha, T.; Osato, K.; Kiuchi, T.; Miida, H.; Okumura, T.; Nakashima, H.

2013-12-01

374

Turion morphological responses to water nutrient concentrations and plant density in the submerged macrophyte Potamogeton crispus  

PubMed Central

Asexual propagules are the dominant means of propagation in most submerged macrophytes. To improve the understanding of how water nutrient concentrations and population density influence the turion production of Potamogeton crispus L., the turions were planted in mesocosms with three water nutrient conditions (ambient lake water, high P and high N) and two plant density levels (4 and 15?turions m?2). After a 9-month experiment, the +P in the water column significantly increased the total turion number per plant under both of the plant density treatments. However, the +N in the water column did not affect the turion number per plant under low plant density. The +P in the water and high plant density significantly reduced the turion individual biomass. An examination of 3210 turion individuals from all treatments revealed that the increased water nutrient concentrations and plant density impacted the turion size by producing different stem diameters of individual turions. Most of the scale leaf morphological traits of the turions were significantly increased under higher water nutrients, but these traits were similar between the different plant density treatments. These results demonstrate that the water P concentration interacts with plant density, affecting both the production and traits of turions. PMID:25399866

Qian, Chang; You, Wenhua; Xie, Dong; Yu, Dan

2014-01-01

375

Water relations, nutrient content and developmental responses of Euonymus plants irrigated with water of different degrees of salinity and quality.  

PubMed

For 20 weeks, the physiological responses of Euonymus japonica plants to different irrigation sources were studied. Four irrigation treatments were applied at 100 % water holding capacity: control (electrical conductivity (EC) <0.9 dS m(-1)); irrigation water normally used in the area (irrigator's water) IW (EC: 1.7 dS m(-1)); NaCl solution, NaCl (EC: 4 dS m(-1)); and wastewater, WW (EC: 4 dS m(-1)). This was followed by a recovery period of 13 weeks, when all the plants were rewatered with the same amount and quality of irrigation water as the control plants. Despite the differences in the chemical properties of the water used, the plants irrigated with NaCl and WW showed similar alterations in growth and size compared with the control even at the end of the recovery period. Leaf number was affected even when the EC of the irrigation water was of 1.7 dS m(-1) (IW), indicating the salt sensitivity of this parameter. Stomatal conductance (gs) and photosynthesis (Pn), as well as stem water potential (?stem), were most affected in plants irrigated with the most saline waters (NaCl and WW). At the end of the experiment the above parameters recovered, while IW plants showed similar values to the control. The higher Na(+) and Cl(+) uptake by NaCl and WW plants led them to show osmotic adjustment throughout the experiment. The highest amount of boron found in WW plants did not affect root growth. Wastewater can be used as a water management strategy for ornamental plant production, as long as the water quality is not too saline, since the negative effect of salt on the aesthetic value of plants need to be taken into consideration. PMID:23306649

Gómez-Bellot, María José; Alvarez, Sara; Castillo, Marco; Bañón, Sebastián; Ortuño, María Fernanda; Sánchez-Blanco, María Jesús

2013-07-01

376

TOXICITY TESTS OF EFFLUENTS WITH MARSH PLANTS IN WATER AND SEDIMENT  

EPA Science Inventory

Methods are described for toxicity testing of water and sediment with the rooted marsh plants, Echinochloa crusgalli var. crusgalli and var. zelavensis (freshwater) and Spartina alterniflora (estuarine). ive industrial effluents, a sewage treatment plant effluent and a herbicide ...

377

System design for a commercial solar Brayton cycle central receiver water desalination plant  

SciTech Connect

The system design for a future commercial solar energy brackish water desalination plant is described. Key features of the plant are discussed along with its configuration selection rationale, design objectives, operation, and performance. 6 refs.

Laakso, J.H.; Zimmerman, D.K.

1981-01-01

378

Singular Value Decomposition Proper Orthogonal Decomposition  

E-print Network

Singular Value Decomposition Proper Orthogonal Decomposition Model Order Reduction Techniques SVD;Singular Value Decomposition Proper Orthogonal Decomposition Singular values and vectors Properties Application: Low-Rank Approximation Singular Value Decomposition Satz For each matrix Y RmÃ?n there exists

Noelle, Sebastian

379

Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit  

PubMed Central

This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset” of environmental data and traits that should be recorded for that. PMID:23423357

Tardieu, François

2013-01-01

380

Biotic vs. Abiotic Control of Decomposition: A Comparison of the Effects of Simulated Extinctions and Changes in Temperature  

PubMed Central

The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5°C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology. PMID:24466351

Boyero, Luz; Cardinale, Bradley J.; Bastian, Mikis; Pearson, Richard G.

2014-01-01

381

Decomposition of water-soluble mononitrosyl iron complexes with dithiocarbamates and of dinitrosyl iron complexes with thiol ligands in animal organisms.  

PubMed

EPR studies have shown that water-soluble mononitrosyl iron complexes with N-methyl-d-glucamine dithiocarbamate (MNIC-MGD) (3 micromol) injected to intact mice were decomposed virtually completely within 1h. The total content of MNIC-MGD in animal urine did not exceed 30 nmol/ml. In the liver, a small amount of MNIC-MGD were converted into dinitrosyl iron complexes (30 nmol/g of liver tissue). The same was observed in intact rabbits in which MNIC-MGD formation was induced by endogenous or exogenous NO binding to NO traps, viz., iron complexes with MGD. In mice, the content of MNIC-MGD in urine samples did not change after bacterial lipopolysaccharide-induced expression of iNOS. It was supposed that MNIC-MGD decomposition in intact animals was largely due to the release of NO from the complexes and its further transfer to other specific acceptors. In mice with iNOS expression, the main contribution to MNIC-MGD decomposition was made by superoxide ions whose destructive effect is mediated by an oxidative mechanism. This effect could fully compensate the augmented synthesis of MNIC-MGD involving endogenous NO whose production was supported by iNOS. Water-soluble dinitrosyl iron complexes (DNIC) with various thiol-containing ligands and thiosulfate injected to intact mice were also decomposed; however, in this case the effect was less pronounced than in the case of MNIC-MGD. It was concluded that DNIC decomposition was largely due to the oxidative effect of superoxide ions on these complexes. PMID:18222183

Serezhenkov, Vladimir A; Timoshin, Alexander A; Orlova, Tsvetina R; Mikoyan, Vasak D; Kubrina, Lioudmila N; Poltorakov, Alexander P; Ruuge, Enno K; Sanina, Natalia A; Vanin, Anatoly F

2008-05-01

382

Dynamic aspects of soil water availability for isohydric plants: Focus on root hydraulic resistances  

NASA Astrophysics Data System (ADS)

Soil water availability for plant transpiration is a key concept in agronomy. The objective of this study is to revisit this concept and discuss how it may be affected by processes locally influencing root hydraulic properties. A physical limitation to soil water availability in terms of maximal flow rate available to plant leaves (Qavail) is defined. It is expressed for isohydric plants, in terms of plant-centered variables and properties (the equivalent soil water potential sensed by the plant, ?s eq; the root system equivalent conductance, Krs; and a threshold leaf water potential, ?leaf lim). The resulting limitation to plant transpiration is compared to commonly used empirical stress functions. Similarities suggest that the slope of empirical functions might correspond to the ratio of Krs to the plant potential transpiration rate. The sensitivity of Qavail to local changes of root hydraulic conductances in response to soil matric potential is investigated using model simulations. A decrease of radial conductances when the soil dries induces earlier water stress, but allows maintaining higher night plant water potentials and higher Qavail during the last week of a simulated 1 month drought. In opposition, an increase of radial conductances during soil drying provokes an increase of hydraulic redistribution and Qavail at short term. This study offers a first insight on the effect of dynamic local root hydraulic properties on soil water availability. By better understanding complex interactions between hydraulic processes involved in soil-plant hydrodynamics, better prospects on how root hydraulic traits mitigate plant water stress might be achieved.

Couvreur, V.; Vanderborght, J.; Draye, X.; Javaux, M.

2014-11-01

383

Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape  

NASA Astrophysics Data System (ADS)

The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when soil moisture is low at shallow depths.

Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

2005-12-01

384

Synergistic integration of ion-exchange and catalytic reduction for complete decomposition of perchlorate in waste water.  

PubMed

Ion-exchange has been frequently used for the treatment of perchlorate (ClO4(-)), but disposal or regeneration of the spent resins has been the major hurdle for field application. Here we demonstrate a synergistic integration of ion-exchange and catalytic decomposition by using Pd-supported ion-exchange resin as an adsorption/catalysis bifunctional material. The ion-exchange capability of the resin did not change after generation of the Pd clusters via mild ethanol reduction, and thus showed very high ion-exchange selectivity and capacity toward ClO4(-). After the resin was saturated with ClO4(-) in an adsorption mode, it was possible to fully decompose the adsorbed ClO4(-) into nontoxic Cl(-) by the catalytic function of the Pd catalysts under H2 atmosphere. It was demonstrated that prewetting the ion-exchange resin with ethanol significantly accelerate the decomposition of ClO4(-) due to the weaker association of ClO4(-) with the ion-exchange sites of the resin, which allows more facile access of ClO4(-) to the catalytically active Pd-resin interface. In the presence of ethanol, >90% of the adsorbed ClO4(-) could be decomposed within 24 h at 10 bar H2 and 373 K. The ClO4(-) adsorption-catalytic decomposition cycle could be repeated up to five times without loss of ClO4(-) adsorption capacity and selectivity. PMID:24894447

Kim, You-Na; Choi, Minkee

2014-07-01

385

Engineering the use of green plants to reduce produced water disposal volume.  

SciTech Connect

In 1990, the Laboratory began an investigation into biological approaches for the reduction of water produced from oil and gas wells. In the spring of 1995, the Company began an on-site experiment at an oil/gas lease in Oklahoma using one of these approaches. The process, known as phytoremediation, utilizes the ability of certain salt tolerant plants to draw the produced water through their roots, transpire the water from their leaves, and thereby reduce overall water disposal volumes and costs. At the Company experimental site, produced water flows through a trough where green plants (primarily cordgrass) have been planted in pea gravel. The produced water is drawn into the plant through its roots, evapotranspirates and deposits a salt residue on the plant leaves. The plant leaves are then harvested and used by a local rancher as cattle feed. The produced water is tested to assure it contains nothing harmful to cattle. In 1996, the Company set up another trough to compare evaporation rates using plants versus using an open container without plants. Data taken during all four seasons (water flow rate, temperature, pH, and conductivity) have shown that using plants to evapotranspirate produced water is safe, more cost effective than traditional methods and is environmentally sound.

Hinchman, R.; Mollock, G. N.; Negri, M. C.; Settle, T.

1998-01-29

386

Rangeland - plant responses to elevated CO{sub 2}. Final report, October 1988--October 1993  

SciTech Connect

Research is described on plant (tallgrass) response to elevated carbon dioxide. Variables addressed include biomass production, as well as water use efficiency, photosynthetic capacity, decomposition, nutrient cycling, and forage quality.

NONE

1997-05-01

387

Optimal Thermolysis Conditions for Soil Carbon Storage on Plant Residue Burning: Modeling the Trade-Off between Thermal Decomposition and Subsequent Biodegradation.  

PubMed

Field burning of plant biomass is a widespread practice that provides charred materials to soils. Its impact on soil C sequestration remains unclear due to the heterogeneity of burning products and difficulty in monitoring the material's biodegradation in fields. Basic information is needed on the relationship between burning conditions and the resulting quantity/quality of residue-derived C altered by thermal decomposition and biodegradation. In this study, we thermolyzed residues (rice straw and husk) at different temperatures (200-600°C) under two oxygen availability conditions and measured thermal mass loss, C compositional change by solid-state C NMR spectroscopy, and biodegradability of the thermally altered residues by laboratory aerobic incubation. A trade-off existed between thermal and microbial decomposition: when burned at higher temperatures, residues experience a greater mass loss but become more recalcitrant via carbonization. When an empirical model accounting for the observed trade-off was projected over 10 to 10 yr, we identified the threshold temperature range (330-400°C) above and below which remaining residue C is strongly reduced. This temperature range corresponded to the major loss of O-alkyl C and increase in aromatic C. The O/C molar ratios of the resultant residues decreased to 0.2 to 0.4, comparable to those of chars in fire-prone field soils reported previously. Although the negative impacts of biomass burning need to be accounted for, the observed relationship may help to assess the long-term fate of burning-derived C and to enhance soil C sequestration. PMID:25602338

Kajiura, Masako; Wagai, Rota; Hayashi, Kentaro

2015-01-01

388

Optimization of conventional water treatment plant using dynamic programming.  

PubMed

In this research, the mathematical models, indicating the capability of various units, such as rapid mixing, coagulation and flocculation, sedimentation, and the rapid sand filtration are used. Moreover, cost functions were used for the formulation of conventional water and wastewater treatment plant by applying Clark's formula (Clark, 1982). Also, by applying dynamic programming algorithm, it is easy to design a conventional treatment system with minimal cost. The application of the model for a case reduced the annual cost. This reduction was approximately in the range of 4.5-9.5% considering variable limitations. Sensitivity analysis and prediction of system's feedbacks were performed for different alterations in proportion from parameters optimized amounts. The results indicated (1) that the objective function is more sensitive to design flow rate (Q), (2) the variations in the alum dosage (A), and (3) the sand filter head loss (H). Increasing the inflow by 20%, the total annual cost would increase to about 12.6%, while 20% reduction in inflow leads to 15.2% decrease in the total annual cost. Similarly, 20% increase in alum dosage causes 7.1% increase in the total annual cost, while 20% decrease results in 7.9% decrease in the total annual cost. Furthermore, the pressure decrease causes 2.95 and 3.39% increase and decrease in total annual cost of treatment plants. PMID:23625909

Mostafa, Khezri Seyed; Bahareh, Ghafari; Elahe, Dadvar; Pegah, Dadras

2013-04-26

389

Water quality investigation of Kingston Fossil Plant dry ash stacking  

SciTech Connect

Changing to a dry ash disposal systems at Kingston Fossil Plant (KFP) raises several water quality issues. The first is that removing the fly ash from the ash pond could alter the characteristics of the ash pond discharge to the river. The second concerns proper disposal of the runoff and possibly leachate from the dry ash stack. The third is that dry ash stacking might change the potential for groundwater contamination at the KFP. This report addresses each of these issues. The effects on the ash pond and its discharge are described first. The report is intended to provide reference material to TVA staff in preparation of environmental review documents for new ash disposal areas at Kingston. Although the investigation was directed toward analysis of dry stacking, considerations for other disposal options are also discussed. This report was reviewed in draft form under the title Assessment of Kingston Fossil Plant Dry Ash Stacking on the Ash Pond and Groundwater Quality.'' 11 refs., 3 figs., 18 tabs.

Bohac, C.E.

1990-04-01

390

Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

391

Identifying Critical Thresholds for Acute Response of Plants and Ecosystems to Water Stress (TARP)  

E-print Network

and dynamic ecosystem simulation models used in the assessment of climatic change 1 Identifying Critical Thresholds for Acute Response of Plants and Ecosystems to Water Stress (TARP. prinus. Furthermore, no significant changes in leaf photosynthesis, conductance or water potential were

392

Litter quality, stream characteristics and litter diversity influence decomposition rates and macroinvertebrates  

E-print Network

Litter quality, stream characteristics and litter diversity influence decomposition rates importance of litter quality and stream characteristics in determining decomposition rate whether plant species diversity affects rate. 3. Decomposition rate was affected by both litter quality

Marks, Jane

393

Georgia-Pacific Palatka Plant Uses Thermal Pinch Analysis and Evaluates Water Reduction in Plant-Wide Energy Assessment  

SciTech Connect

This OIT BestPractices Case Study describes the methods and results used in a plant-wide assessment at a Georgia-Pacific paper mill in Palatka, FL. Assessment personnel recommended several projects, which, if implemented, have the potential to save the plant more than 729,000 MMBtu per year and$2.9 million per year. In addition, the plant could reduce water use by 2,100 gallons per minute.

Not Available

2002-12-01

394

Woodland Decomposition.  

ERIC Educational Resources Information Center

Outlines the role of the main organisms involved in woodland decomposition and discusses some of the variables affecting the rate of nutrient cycling. Suggests practical work that may be of value to high school students either as standard practice or long-term projects. (CW)

Napier, J.

1988-01-01

395

Sector Decomposition  

E-print Network

Sector decomposition is a constructive method to isolate divergences from parameter integrals occurring in perturbative quantum field theory. We explain the general algorithm in detail and review its application to multi-loop Feynman parameter integrals as well as infrared divergent phase-space integrals over real radiation matrix elements.

Gudrun Heinrich

2008-05-16

396

The integrated nanofiltration system of the Méry-sur-Oise surface water treatment plant (37 mgd)  

Microsoft Academic Search

A large-scale nanofiltration plant will produce 140,00 m3\\/day of permeate in the Paris Area from river water. The river water must undergo pretreatment before nanofiltration. The water varying temperature is also a specificity. A nanofiltration prototype since 1993 distributes water to 6,000 residents of Auvers-sur-Oise. It allowed to design a large-scale plant at minimum energy and chemicals costs. A new

Claire Ventresque; Guy Bablon

1997-01-01

397

Coupled Oxygen and Hydrogen Isotope Analysis of Water Along the Soil-Plant- Atmosphere Continuum  

NASA Astrophysics Data System (ADS)

The oxygen and hydrogen isotope compositions of water within a plant vary with transpiration rates and the isotopic composition of soil water. Both of these parameters are affected by temperature and relative humidity. A controlled-temperature, growth-chamber experiment was conducted to determine the relationships among temperature, relative humidity, soil water evaporation and plant-water isotope composition in cattails and horsetails. Typha, a cattail species that grows in wetland conditions, and Equisetum, a horsetail species that prefers dry soils, were each grown in four chambers at 15, 20, 25 and 30 degrees Celsius. The oxygen and hydrogen isotope compositions of watering water, soil water, vapour in the growth chambers and plant water from the leaves and stems were analyzed throughout the eight-month long artificial growing season. Although the oxygen isotope composition of the watering water remained constant, the soil water, atmospheric vapour and plant water were progressively enriched in oxygen-18 and deuterium in each of the four chambers from low to high temperatures as a result of increasing evaporation. The oxygen isotope composition of plant water along the length of a single stem or leaf was increasingly enriched in the heavier isotopes towards the apex. There was no significant difference in the magnitude of this trend between species. These results indicate that the isotopic composition of plant water is primarily controlled by environmental conditions. The oxygen isotope composition of the water vapour in the growing chamber increased with temperature, consistent with equilibration between the vapour and the oxygen-18 enriched soil and plant water reservoirs. The magnitude and interaction of these variables, as measured for these modern samples of cattails and horsetails, should be useful in calibrating paleoclimate proxies based on fossilized plant materials (e.g., cellulose, phytoliths).

Huang, Z.; Webb, E. A.; Longstaffe, F. J.

2008-12-01

398

Dioecy Impacts on Plant Water Fluxes in Riparian Ecosystems  

NASA Astrophysics Data System (ADS)

Dioecious plants are frequently associated with different spatial distributions of the two sexes across resource gradients. Segregation between sexes might be expected to occur if the cost of reproduction is greater in females than in males. If so, females would be under stronger selection to increase rates of resource uptake. Acer negundo is a dioecious riparian tree species that show spatial segregation among sexes: females are typically more common along streamside (high resource) environments than males. The spatial segregation of the sexes leads to the hypothesis that male and female individuals have varying influence on ecohydrological processes. To address this, we measured sap flux, water relations and hydraulic architecture of mature streamside (less than 1 m from stream channel) male and female Acer negundo trees occurring near Salt Lake City, Utah, USA during the 2004 growing season. Despite similar predawn and midday leaf water potentials, sap flux density ( Js) was 40 percent higher in female trees than in male trees during the 2004 growing season (n = 42 days, F = 73.56, P < 0.0001). Both genders showed a similar relationship between conducting sapwood area to stem diameter ratio suggesting that differences in Js scale to the whole tree level. Sap flux data from Acer negundo trees was compared to five other co-occurring riparian tree species. Female Acer negundo trees showed the highest Js among all species while Js in male Acer negundo trees was lower than all other species except one ( Acer grandidentatum). These data demonstrate that individual female Acer negundo trees have the capacity remove water at higher rates than males in high resource environments. The spatial segregation of the sexes along streamside environments may therefore have profound impacts on ecohydrological processes such as stream discharge, groundwater recharge, and nutrient cycling.

Hultine, K. R.; Bush, S. E.; West, A. G.; Ehleringer, J. R.

2005-12-01

399

[Pilot-scale study on riparian mixed plant zones treating polluted river water].  

PubMed

The polluted river water is treated with pilot-scale riparian zones of no aquatic plant, Vetiveria zizanioides + submerged plants, and weed+ Typha angustifolia L. + Phragmites communis. It is shown that the vegetation water zones are better than the no vegetation water zone and Vetiveria zizanioides + submerged plants zone is the best in improving water quality. The average removals of the Vetiveria zizanioides + submerged plant zone is 43.5% COD, 71.1% ammonia and 69.3% total phosphorus respectively. The dissolved oxygen (DO) and temperature of effluents from the three water zones are also investigated. It shows that DO of effluent from the vegetation zones are more stable than that of effluent from the no vegetation zone, and the temperature of the effluent from the vegetation zones are lower than that from the no vegetation zones. The submerged plants have special role in water quality improvement, and should be studied further. PMID:16767981

Li, Rui-hua; Guan, Yun-tao; He, Miao; Hu, Hong-yin; Jiang, Zhan-peng

2006-04-01

400

Elevated Carbon Dioxide and Litter Decomposition in California Annual  

E-print Network

concentra- tion ([CO2]) on litter decomposition has focused on changes in the leaf litter quality quality; plant litter; serpentine grassland; soil microbiota; soil moisture; species compositionElevated Carbon Dioxide and Litter Decomposition in California Annual Grasslands: Which Mechanisms

Dukes, Jeffrey

401

Water use at pulverized coal power plants with postcombustion carbon capture and storage.  

PubMed

Coal-fired power plants account for nearly 50% of U.S. electricity supply and about a third of U.S. emissions of CO(2), the major greenhouse gas (GHG) associated with global climate change. Thermal power plants also account for 39% of all freshwater withdrawals in the U.S. To reduce GHG emissions from coal-fired plants, postcombustion carbon capture and storage (CCS) systems are receiving considerable attention. Current commercial amine-based capture systems require water for cooling and other operations that add to power plant water requirements. This paper characterizes and quantifies water use at coal-burning power plants with and without CCS and investigates key parameters that influence water consumption. Analytical models are presented to quantify water use for major unit operations. Case study results show that, for power plants with conventional wet cooling towers, approximately 80% of total plant water withdrawals and 86% of plant water consumption is for cooling. The addition of an amine-based CCS system would approximately double the consumptive water use of the plant. Replacing wet towers with air-cooled condensers for dry cooling would reduce plant water use by about 80% (without CCS) to about 40% (with CCS). However, the cooling system capital cost would approximately triple, although costs are highly dependent on site-specific characteristics. The potential for water use reductions with CCS is explored via sensitivity analyses of plant efficiency and other key design parameters that affect water resource management for the electric power industry. PMID:21329343

Zhai, Haibo; Rubin, Edward S; Versteeg, Peter L

2011-03-15

402

Chemical Properties, Decomposition, and Methane Production of Tertiary Relict Plant Litters: Implications for Atmospheric Trace Gas Production in the Early Tertiary  

NASA Astrophysics Data System (ADS)

Throughout the early Tertiary (ca. 65-38 Ma) Taxodiaceae-dominated (redwood) wetland forests occupied the high latitudes and were circumpolar in their distribution. Many of these forests had high standing biomass with moderate primary productivity. The geographic extent and amount of Tertiary coals and fossil forests throughout Arctic Canada suggests large areas of wetland forests that may have cycled substantial quantities of carbon, particularly methane until they were replaced by cold tolerant Pinus, Picea, and Larix following climatic cooling associated with the Terminal Eocene Event. To test this hypothesis we compared physiochemical properties, decomposition, and trace gas production of litter from extant Metasequoia, Pinus, Picea, and Larix. Initial results from plantation-grown trees indicate Metasequoia litter is a better source of labile organic substrate than pinaceous litter. Metasequoia litter contained the least lignin and highest amounts of water-soluble compounds of the four litter types studied. Analysis of the lignin structure using cupric oxide oxidation indicates that Metasequoia lignin is enriched in 4'-hydroxyacetophenone and 4'- Hydroxy-3'-methoxyacetophenone relative to the pinaceous litter. In a 12-month decomposition study using litterbags, average litter mass loss was greater for Metasequoia litter (62%) compared to the pinaceous species (50%). Moreover, Metasequoia litter incubated under anoxic conditions produced nearly twice as much CO2 (ca. 4.2 umol/g.day) and CH4 (2.1 umol/g.day) as the pinaceous litter (2.4 umol/g.day for CO2; 1.2 umol/g.day for CH4). Our results support the idea of greater decomposability and palatability of Metasequoia litter as compared to Larix, Picea, or Pinus. Provided that the biochemical properties of Metasequoia have remained relatively stable through geologic time, it appears that early Tertiary Metasequoia-dominated wetland forests may have had higher microbial driven trace gas production than the Pinaceae-dominated forests that replaced them in the late Tertiary.

Yavitt, J. B.; Bartella, T. M.; Williams, C. J.

2006-12-01

403

Hydraulics of Asteroxylon mackei, an early Devonian vascular plant, and the early evolution of water transport tissue in terrestrial plants.  

PubMed

The core of plant physiology is a set of functional solutions to a tradeoff between CO(2) acquisition and water loss. To provide an important evolutionary perspective on how the earliest land plants met this tradeoff, we constructed a mathematical model (constrained geometrically with measurements of fossils) of the hydraulic resistance of Asteroxylon, an Early Devonian plant. The model results illuminate the water transport physiology of one of the earliest vascular plants. Results show that Asteroxylon's vascular system contains cells with low hydraulic resistances; these resistances are low because cells were covered by scalariform pits, elliptical structures that permit individual cells to have large areas for water to pass from one cell to another. Asteroxylon could move a large amount of water quickly given its large pit areas; however, this would have left these plants particularly vulnerable to damage from excessive evapotranspiration. These results highlight a repeated pattern in plant evolution, wherein the evolution of highly conductive vascular tissue precedes the appearance of adaptations to increase water transport safety. Quantitative insight into the vascular transport of Asteroxylon also allows us to reflect on the quality of CO(2) proxy estimates based on early land plant fossils. Because Asteroxylon's vascular tissue lacked any safety features to prevent permanent damage, it probably used stomatal abundance and behavior to prevent desiccation. If correct, low stomatal frequencies in Asteroxylon reflect the need to limit evapotranspiration, rather than adaptation to high CO(2) concentrations in the atmosphere. More broadly, methods to reveal and understand water transport in extinct plants have a clear use in testing and bolstering fossil plant-based paleoclimate proxies. PMID:21244621

Wilson, J P; Fischer, W W

2011-03-01

404

Temporal patterns of litter production by vascular plants and its decomposition rate in cut-over peatlands  

Microsoft Academic Search

Peatlands are an important carbon (C) store but many have been drained and damaged by mechanical harvesting. Little is known\\u000a about ecological processes on abandoned peatlands that have recolonized naturally nor the impact of plants on C balance of\\u000a these sites. Over the course of 13 months, we measured amounts of litter falling from three different species colonizing an\\u000a abandoned

Clare J. Trinder; Rebekka R. E. Artz; David Johnson

2008-01-01

405

Importance of permafrost as a source of water for plants in east Siberian taiga  

Microsoft Academic Search

Stable oxygen isotope ratios of plant water (sap water) were observed at Spasskaya Pad experimental forest near Yakutsk, Russia in 1997–1999. The ? 18O of sap water in larch trees ( Larix gmelinii) decreased soon after leaf unfolding every year, indicating that snowmelt water was used in the beginning of summer. During mid to late summer, a clear difference in

Atsuko Sugimoto; Nao Yanagisawa; Daisuke Naito; Noboru Fujita; Trofim C. Maximov

2002-01-01

406

Water relations of four perennial plant species at the southern periphery of the Taklimakan desert  

Microsoft Academic Search

The investigations started from the assumption that perennial plants in the foreland of river oases in the Taklimakan desert are able to take up water from soils of low water content and low water potential during long drought periods. In order to check this assumption, P-V curves were established and selected water relation parameters were derived. Alhagi sparsifolia, Calligonum caput-medusae,

XiangYi Li; LiSha Lin; FanJiang Zeng; XiMing Zhang

2011-01-01

407

Improvement of chemical control in the water-steam cycle of thermal power plants  

Microsoft Academic Search

A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and

Vladana N. Rajakovi?-Ognjanovi?; Dragana Z. Živojinovic; Branimir N. Grgur; Ljubinka V. Rajakovi?

2011-01-01

408

100 kW CC-OTEC Plant and Deep Ocean water Applications  

E-print Network

. / 1st Power Generation Test Succeeded Surface Water: 23.5 oC, 330t/h Deep Water: 9.3 oC, 250t/h Power100 kW CC-OTEC Plant and Deep Ocean water Applications in Kumejima, Okinawa, Japan Katsuya Furugen in Kumejima (Okinawa) Okinawa Prefectural Deep Sea Water Research Center, since 2000 OTEC Demonstration

409

Volatilization of selenium from astragalus plants irrigated with selenium-laden water. Open file report  

SciTech Connect

Living plants of Astragalus bisulcatus and Atriplex canescens were irrigated with solutions containing selenium to investigate the plants' ability to selectively remove selenium from selenium-contaminated water. The plants were grown from seed in an indoor environment and harvested for analysis at the end of a typical 7-month growing season. Of the total selenium applied to soil in which the plants were grown, only about 1% was incorporated in plant tissues of Astragalus, but approximately 18% of applied selenium was dissipated into the air from the living plants. Atriplex plants did not absorb or dissipate detectable amounts of selenium.

MacDonald, D.J.; Lujan, M.J.; Ary, T.S.

1989-01-01

410

Evaluation of coal-gasification - combustion-turbine power plants emphasizing low water consumption  

SciTech Connect

A cost and performance study was made of several integrated power plants using coal gasification technology now in advanced development and combustion turbines for power generation. The principal emphasis was placed on studying plants using air cooling and comparing costs and performance of those plants with water-cooled coal gasification-combined-cycle (GCC) and conventional coal-fired power plants. The major objective was to determine whether cost and performance penalties would be prohibitive for air-cooled plants that use yet-to-be-developed coal gasifiers and commercially available combustion turbines for topping cycle power. The results indicate the following: air-cooled GCC plants using conceptual designs of either the Texaco or the British Gas Corporation (BGC) slaging gasifier could have coal-to-net electric power efficiencies equivalent to that of a water-cooled conventional coal-fired plant; the air-cooled GCC plants could produce electricity at busbar cost 1 to 3 mills per kWh (1980 dollars) less than busbar cost in a water-cooled conventional plant and only up to 2 mills per kWh higher than busbar cost in a water-cooled Texaco GCC plant; and even a simple-cycle regenerative combustion turbine plant fueled with gas from the BGC gasifier could have a coal-to-net electric power efficiency of over 30% and a busbar cost competitive with that in a water cooled conventional plant. The principal reason that air-cooled power plants using combustion turbines could be competitive with conventional water-cooled, coal-fired steam plants is that a majority of net power is produced by the combustion turbines, which require no cooling water. This, in turn, leads to a reduced cost and performance penalty when bottoming steam-cycle condensers are air-cooled.

Cavazo, R.; Clemmer, A.B.; de la Mora, J.A.; Grisso, J.R.; Klumpe, H.W.; Meissner, R.E.; Musso, A.; Roszkowski, T.R.

1982-01-01

411

Geographic, technologic, and economic analysis of using reclaimed water for thermoelectric power plant cooling.  

PubMed

Use of reclaimed water-municipal wastewater treatment plant effluent-in nonpotable applications can be a sustainable and efficient water management strategy. One such nonpotable application is at thermoelectric power plants since these facilities require cooling, often using large volumes of freshwater. To evaluate the geographic, technologic, and economic feasibility of using reclaimed water to cool thermoelectric power plants, we developed a spatially resolved model of existing power plants. Our model integrates data on power plant and municipal wastewater treatment plant operations into a combined geographic information systems and optimization approach to evaluate the feasibility of cooling system retrofits. We applied this broadly applicable methodology to 125 power plants in Texas as a test case. Results show that sufficient reclaimed water resources exist within 25 miles of 92 power plants (representing 61% of capacity and 50% of generation in our sample), with most of these facilities meeting both short-term and long-term water conservation cost goals. This retrofit analysis indicates that reclaimed water could be a suitable cooling water source for thermoelectric power plants, thereby mitigating some of the freshwater impacts of electricity generation. PMID:24625241

Stillwell, Ashlynn S; Webber, Michael E

2014-04-15

412

A global experiment suggests climate warming will not accelerate litter decomposition in streams but might reduce carbon sequestration.  

PubMed

The decomposition of plant litter is one of the most important ecosystem processes in the biosphere and is particularly sensitive to climate warming. Aquatic ecosystems are well suited to studying warming effects on decomposition because the otherwise confounding influence of moisture is constant. By using a latitudinal temperature gradient in an unprecedented global experiment in streams, we found that climate warming will likely hasten microbial litter decomposition and produce an equivalent decline in detritivore-mediated decomposition rates. As a result, overall decomposition rates should remain unchanged. Nevertheless, the process would be profoundly altered, because the shift in importance from detritivores to microbes in warm climates would likely increase CO(2) production and decrease the generation and sequestration of recalcitrant organic particles. In view of recent estimates showing that inland waters are a significant component of the global carbon cycle, this implies consequences for global biogeochemistry and a possible positive climate feedback. PMID:21299824

Boyero, Luz; Pearson, Richard G; Gessner, Mark O; Barmuta, Leon A; Ferreira, Verónica; Graça, Manuel A S; Dudgeon, David; Boulton, Andrew J; Callisto, Marcos; Chauvet, Eric; Helson, Julie E; Bruder, Andreas; Albariño, Ricardo J; Yule, Catherine M; Arunachalam, Muthukumarasamy; Davies, Judy N; Figueroa, Ricardo; Flecker, Alexander S; Ramírez, Alonso; Death, Russell G; Iwata, Tomoya; Mathooko, Jude M; Mathuriau, Catherine; Gonçalves, José F; Moretti, Marcelo S; Jinggut, Tajang; Lamothe, Sylvain; M'Erimba, Charles; Ratnarajah, Lavenia; Schindler, Markus H; Castela, José; Buria, Leonardo M; Cornejo, Aydeé; Villanueva, Verónica D; West, Derek C

2011-03-01

413

New developments in upgrading waste-water treatment plant effluent using ultrafiltration  

Microsoft Academic Search

In the Netherlands interest in advanced treatment is increasing now that almost all waste-water treatment plants apply full biological treatment and nutrient removal. Membrane filtration, especially ultrafiltration, of waste-water treatment plant effluent appears to be a very promising method. However, many experiments show a rapid decrease in flux, which means that frequent and intensive cleaning is required. Various methods for

Jaap H. J. M. van der Graaf; Jelle H. Roorda

2000-01-01

414

A Series RCL Circuit Theory for Analyzing Non-Steady-State Water Uptake of Maize Plants  

NASA Astrophysics Data System (ADS)

Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths.

Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

2014-10-01

415

A Series RCL Circuit Theory for Analyzing Non-Steady-State Water Uptake of Maize Plants  

PubMed Central

Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths. PMID:25335512

Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

2014-01-01

416

A series RCL circuit theory for analyzing non-steady-state water uptake of maize plants.  

PubMed

Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths. PMID:25335512

Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

2014-01-01

417

The Diffusion of Biological Waste-Water Treatment Plants in the Dutch Food and Beverage Industry  

Microsoft Academic Search

This article develops an economic model of environmental technology adoption decisions. The model is applied econometrically to the diffusion of biological waste-water treatment plants in the Dutch food and beverage industry. It shows that it is possible to explain the overall diffusion pattern of biological waste-water treatment plants in terms of a rational choice model in which prospective adopters trade

René Kemp

1998-01-01

418

Improvement of growth rate of plants by bubble discharge in water  

NASA Astrophysics Data System (ADS)

The effect of bubble discharge in water on the growth rate of plants was investigated experimentally for application to plant cultivation systems. Spinach (Spinacia oleracea), radish (Raphanus sativus var. sativus), and strawberry (Fragaria × ananassa) were used as specimens to clarify the effect of the discharge treatment on edible parts of the plants. The specimens were cultivated in pots filled with artificial soil, which included chicken manure charcoal. Distilled water was sprayed on the artificial soil and drained through a hole in the pots to a water storage tank. The water was circulated from the water storage tank to the cultivation pots after 15 or 30 min discharge treatment on alternate days. A magnetic compression-type pulsed power generator was used to produce the bubble discharge with a repetition rate of 250 pps. The plant height in the growth phase and the dry weight of the harvested plants were improved markedly by the discharge treatment in water. The soil and plant analyzer development (SPAD) value of the plants also improved in the growth phase of the plants. The concentration of nitrate nitrogen, which mainly contributed to the improvement of the growth rate, in the water increased with the discharge treatment. The Brix value of edible parts of Fragaria × ananassa increased with the discharge treatment. The inactivation of bacteria in the water was also confirmed with the discharge treatment.

Takahata, Junichiro; Takaki, Koichi; Satta, Naoya; Takahashi, Katsuyuki; Fujio, Takuya; Sasaki, Yuji

2015-01-01

419

Model-Free Based Water Level Control for Hydroelectric Power Plants  

E-print Network

Model-Free Based Water Level Control for Hydroelectric Power Plants Cédric JOIN Gérard ROBERT polytechnique, 91128 Palaiseau, France (e-mail: Michel.Fliess@polytechnique.edu) Abstract: Automatic water level for hydroelectric run-of-the river power plants. To modulate power generation, a level trajectory is planned

Paris-Sud XI, Université de

420

ECOSYSTEM ECOLOGY -ORIGINAL PAPER Spatial and temporal variability of plant-available water  

E-print Network

ECOSYSTEM ECOLOGY - ORIGINAL PAPER Spatial and temporal variability of plant-available water vertical and temporal distribu- tion of plant-available water (PAW). To investigate this hypothesis, PAW winter and summer compared to the non-carbonate soil. Following a wet summer, continuously cemented

Ahmad, Sajjad

421

Using Impinging Stream to Kill Algae, Fungi and Bacteria in Cooling Water of Thermal Power Plants  

Microsoft Academic Search

The growth of living organism like algae, fungi and bacteria in the cooling-water system of thermal power plants may cause biological fouling. In this paper, a novel method using impinging stream was proposed to kill algae, fungi and bacteria in cooling water of thermal power plants. Using yeast cells as an example, the method of yeast cell disruption by a

Xia Yang; Jia Guo; Yu-xin Zhou; Yuan Wu; Hong-qiang Zhang; Lin Zhang

2011-01-01

422

The Impact of Soil Water Repellency on Hydrological Properties of Soil, the Plant Growing Environment, Irrigation Efficiency and Water Consumption  

NASA Astrophysics Data System (ADS)

Soil water repellency causes at least temporal changes in the hydrological properties of a soil. These changes, among other things, often result in suboptimal growing conditions, reduced crop performance, and/or increased irrigation requirements. Water repellency in soil is more wide spread than previously thought and has been identified in many soil types under a wide array of climatic conditions and cropping systems worldwide. (Dekker et al., 2005) The reduction or loss of soil wettability caused by soil water repellency leads to drastically different hydrological behavior (Dekker et al. 2009), and reduces the ability of the soil to function as expected. Consequences of soil water repellency include increased runoff and preferential flow, reduced plant available water, reduced irrigation efficiency, suboptimal crop performance, increased requirement for water and other inputs, and increased potential for non-point source pollution. (Dekker et al., 2001) This presentation consolidates information on basic hydrological and soil system functions as they relate to the plant growth environment, irrigation efficiency and water conservation, and shows the differences between what happens in soils affected by varying levels of soil water repellency compared to wettable soils or soils where soil surfactants have been used to restore/optimize wettability. The impact on irrigation efficiency and the plant growth environment is also discussed. The conclusion is that the impact of soil water repellency compromises hydrological properties and the plant growth environment in a wider range of conditions than previously recognized and, therefore, deserves consideration in the management of soil and water in crop systems.

Moore, Demie; Kostka, Stanley; Boerth, Thomas; McMillan, Mica; Ritsema, Coen; Dekker, Louis; Oostindie, Klaas; Stoof, Cathelijne; Wesseling, Jan

2010-05-01

423

ONE MGD ION EXCHANGE PLANT FOR REMOVAL OF NITRATE FROM WELL WATER  

EPA Science Inventory

A full scale 1 mgd demonstration plant, using ion exchange, for removal of nitrate from well water was built at McFarland, California. The plant has been performing satisfactorily in the semi-automatic mode since October 1983. Full automation of the plant was completed in June 19...

424

MAGNITUDE AND MECHANISMS OF DISEQUILIBRIUM BETWEEN PREDAWN PLANT AND SOIL WATER POTENTIALS  

Microsoft Academic Search

Predawn plant water potential (Cw, measured with leaf psychrometers) and surrogate measurements made with the pressure chamber (termed Cpc here) are used to infer comparative ecological performance, based on the expectation that these plant po- tentials reflect the wettest soil Cw accessed by roots. There is growing evidence, however, that some species exhibit substantial predawn disequilibrium (PDD), defined as plant

Lisa A. Donovan; James H. Richards; Matthew J. Linton

2003-01-01

425

URANIUM ACCUMULATION BY AQUATIC PLANTS FROM URANIUM-CONTAMINATED WATER IN CENTRAL PORTUGAL  

Microsoft Academic Search

Several species of plants have developed a tolerance to metal that enables them to survive in metal contaminated and polluted sites. Some of these aquatic plants have been reported to accumulate significant amounts of specific trace elements and are, therefore, useful for phytofiltration. This work focuses the potential of aquatic plants for the phytofiltration of uranium (U) from contaminated water.

João Pratas; Paulo J. C. Favas; Carlos Paulo; Nelson Rodrigues; M. N. V. Prasad

2012-01-01

426

Uranium accumulation by aquatic plants from uranium-contaminated water in Central Portugal  

Microsoft Academic Search

Several species of plants have developed a tolerance to metal that enables them to survive in metal contaminated and polluted sites. Some of these aquatic plants have been reported to accumulate significant amounts of specific trace elements and are, therefore, useful for phytofiltration. This work focuses the potential of aquatic plants for the phytofiltration of uranium (U) from contaminated water.

João Pratas; Paulo J. C. Favas; Carlos Paulo; Nelson Rodrigues; M. N. V. Prasad

2011-01-01

427

Chlorophyll fluorescence as an indicator of plant water status in cotton  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various methods exist for the measurement of plant water status. Plant breeders value methods that are fast and inexpensive lending themselves to the efficient evaluation of large segregating populations. Chlorophyll fluorescence is a parameter commonly measured by plant physiologists when studying ...

428

ACCEPTED BY WATER ENVIRONMENT RESEARCH ODOR AND VOC REMOVAL FROM WASTEWATER TREATMENT PLANT  

E-print Network

ACCEPTED BY WATER ENVIRONMENT RESEARCH _______ ODOR AND VOC REMOVAL FROM WASTEWATER TREATMENT PLANT of biofilters for sequential removal of H2S and VOCs from wastewater treatment plant waste air. The biofilter) respectively. In field studies performed at the City of Los Angeles' Hyperion Treatment Plant, excellent

429

Plant nitrogen uptake drives responses of productivity to nitrogen and water addition in a grassland  

PubMed Central

Increased atmospheric nitrogen (N) deposition and altered precipitation regimes have profound impacts on ecosystem functioning in semiarid grasslands. The interactions between those two factors remain largely unknown. A field experiment with N and water additions was conducted in a semiarid grassland in northern China. We examined the responses of aboveground net primary production (ANPP) and plant N use during two contrasting hydrological growing seasons. Nitrogen addition had no impact on ANPP, which may be accounted for by the offset between enhanced plant N uptake and decreased plant nitrogen use efficiency (NUE). Water addition significantly enhanced ANPP, which was largely due to enhanced plant aboveground N uptake. Nitrogen and water additions significantly interacted to affect ANPP, plant N uptake and N concentrations at the community level. Our observations highlight the important role of plant N uptake and use in mediating the effects of N and water addition on ANPP. PMID:24769508

Lü, Xiao-Tao; Dijkstra, Feike A.; Kong, De-Liang; Wang, Zheng-Wen; Han, Xing-Guo

2014-01-01

430

POTENTIAL WATER QUANTITY AND WATER QUALITY IMPACTS OF POWER PLANT DEVELOPMENT SCENARIOS ON MAJOR RIVERS IN THE OHIO BASIN  

EPA Science Inventory

This report was prepared in support of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. Water consumption levels associated with power plant cooling were estimated for different energy develop...

431

El-Salaam Canal Water, Sinai, Egypt. Part V. Techno-economic study for integrated treatment plant  

Microsoft Academic Search

The water quality of El-Salaam canal, in Sinai, Egypt is chemically and biologically polluted because it is a mixture of Nile water and Drainage water. Complex treatment plant is proposed which consists of three types of plants: primary water filtration and chlorination (PWFC) treatment plant of 20,000 m3\\/day capacity, ultrafiltration (UF) water treatment plant of 2400 \\/day capacity and brackish

Azza Hafez; Maaly Khedr; Kamel El-Katib; Hanaa Gadallah

2009-01-01

432

Evaluation of Effectiveness Technological Process of Water Purification Exemplified on Modernized Water Treatment Plant at Otoczna  

NASA Astrophysics Data System (ADS)

The article presents the work of the Water Treatment Plant in the town of Otoczna, located in the Wielkopolska province, before and after the modernization of the technological line. It includes the quality characteristics of the raw water and treated water with particular emphasis on changes in the quality indicators in the period 2002 -2012 in relation to the physicochemical parameters: the content of total iron and total manganese, the ammonium ion as well as organoleptic parameters(colour and turbidity). The efficiency of technological processes was analysed, including the processes of bed start up with chalcedonic sand to remove total iron and manganese and ammonium ion. Based on the survey, it was found that the applied modernization helped solve the problem of water quality, especially the removal of excessive concentrations of iron, manganese and ammonium nitrogen from groundwater. It has been shown that one year after modernization of the technological line there was a high reduction degree of most parameters, respectively for the general iron content -99%, general manganese - 93% ammonia - 93%, turbidity - 94%. It has been proved, that chalcedonic turned out to be better filter material than quartz sand previously used till 2008. The studies have confirmed that the stage of modernization was soon followed by bed start-up for removing general iron from the groundwater. The stage of manganese removal required more time, about eight months for bed start-up. Furthermore, the technological modernization contributed to the improvement of the efficiency of the nitrification process.

Jordanowska, Joanna; Jakubus, Monika

2014-12-01

433

Plant Anatomy and Reproduction Plants have three main parts Absorb water  

E-print Network

Secondary Growth Plant Responses #12;7 Gravitropism above; phototropism to the right Plant Hormones Many. Angiosperm Seeds Seeds open to the outside Seeds NOT open to outside #12;6 Plant Growth Primary Growth plant responses controlled by chemicals called hormones Auxins are involved in the control of plant

Brown, Christopher A.

434

Beyond hypoxia: occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake.  

PubMed

Organic matter-induced black blooms (hypoxia and an offensive odor) are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration (close to 0 mg/L), low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe2+ and sigmaS(2-) were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column. PMID:25076519

Shen, Qiushi; Zhou, Qilin; Shang, Jingge; Shao, Shiguang; Zhang, Lei; Fan, Chengxin

2014-02-01

435

Reducing water freshwater consumption at coal-fired power plants : approaches used outside the United States  

Microsoft Academic Search

Coal-fired power plants consume huge quantities of water, and in some water-stressed areas, power plants compete with other users for limited supplies. Extensive use of coal to generate electricity is projected to continue for many years. Faced with increasing power demands and questionable future supplies, industries and governments are seeking ways to reduce freshwater consumption at coal-fired power plants. As

Elcock

2011-01-01

436

The role of SWRO Barcelona-Llobregat Plant in the water supply system of Barcelona Area  

Microsoft Academic Search

Barcelona-Llobregat Desalination Plant is actually the largest seawater desalination plant in Europe producing potable water from the seawater of the Mediterranean Sea. The plant is able to supply approximately the 20% of tap water of Barcelona Metropolitan area having a maximum capacity of 200,000?cubic meters per day. This project was developed by Aigües Ter-Llobregat, public company of the Catalonian Government

Miguel Angel Sanz; Carlos Miguel

2012-01-01

437

The use of soil electrical resistivity to monitor plant and soil water relationships in vineyards  

NASA Astrophysics Data System (ADS)

Soil water availability deeply affects plant physiology. In viticulture it is considered as a major contributor to the "terroir" expression. The assessment of soil water in field conditions is a difficult task especially over large surfaces. New techniques, are therefore required to better explore variations of soil water content in space and time with low disturbance and with great precision. Electrical Resistivity Tomography (ERT) meets these requirements, for applications in plant sciences, agriculture and ecology. In this paper, possible techniques to develop models that allow the use of ERT to spatialise soil water available to plants are reviewed. An application of soil water monitoring using ERT in a grapevine plot in Burgundy (north-east of France) during the vintage 2013 is presented. We observed the lateral heterogeneity of ERT derived Fraction of Transpirable Soil Water (FTSW) variations, and differences in water uptake depending on grapevine water status (leaf water potentials measured both at predawn and at solar noon and contemporary to ERT monitoring). Active zones in soils for water movements were identified. The use of ERT in ecophysiological studies, with parallel monitoring of plant water status, is still rare. These methods are promising because they have the potential to reveal a hidden part of a major function of plant development: the capacity to extract water from the soil.

Brillante, L.; Mathieu, O.; Bois, B.; van Leeuwen, C.; Lévêque, J.

2014-10-01

438

The use of soil electrical resistivity to monitor plant and soil water relationships in vineyards  

NASA Astrophysics Data System (ADS)

Soil water availability deeply affects plant physiology. In viticulture it is considered a major contributor to the "terroir" effect. The assessment of soil water in field conditions is a difficult task, especially over large surfaces. New techniques are therefore required in order to better explore variations of soil water content in space and time with low disturbance and with great precision. Electrical resistivity tomography (ERT) meets these requirements for applications in plant sciences, agriculture and ecology. In this paper, possible techniques to develop models that allow the use of ERT to spatialise soil water available to plants are reviewed. An application of soil water monitoring using ERT in a grapevine plot in Burgundy (north-east France) during the vintage 2013 is presented. We observed the lateral heterogeneity of ERT-derived fraction of transpirable soil water (FTSW) variations, and differences in water uptake depend on grapevine water status (leaf water potentials measured both at predawn and at solar noon and contemporary to ERT monitoring). Active zones in soils for water movements were identified. The use of ERT in ecophysiological studies, with parallel monitoring of plant water status, is still rare. These methods are promising because they have the potential to reveal a hidden part of a major function of plant development: the capacity to extract water from the soil.

Brillante, L.; Mathieu, O.; Bois, B.; van Leeuwen, C.; Lévêque, J.

2015-03-01

439

Optimization under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

SciTech Connect

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazar; Stephen E. Zitney; Urmila Diwekar

2009-01-01

440

Optimization Under Uncertainty for Water Consumption in a Pulverized Coal Power Plant  

SciTech Connect

Pulverized coal (PC) power plants are widely recognized as major water consumers whose operability has started to be affected by drought conditions across some regions of the country. Water availability will further restrict the retrofitting of existing PC plants with water-expensive carbon capture technologies. Therefore, national efforts to reduce water withdrawal and consumption have been intensified. Water consumption in PC plants is strongly associated to losses from the cooling water cycle, particularly water evaporation from cooling towers. Accurate estimation of these water losses requires realistic cooling tower models, as well as the inclusion of uncertainties arising from atmospheric conditions. In this work, the cooling tower for a supercritical PC power plant was modeled as a humidification operation and used for optimization under uncertainty. Characterization of the uncertainty (air temperature and humidity) was based on available weather data. Process characteristics including boiler conditions, reactant ratios, and pressure ratios in turbines were calculated to obtain the minimum water consumption under the above mentioned uncertainties. In this study, the calculated conditions predicted up to 12% in reduction in the average water consumption for a 548 MW supercritical PC power plant simulated using Aspen Plus. Optimization under uncertainty for these large-scale PC plants cannot be solved with conventional stochastic programming algorithms because of the computational expenses involved. In this work, we discuss the use of a novel better optimization of nonlinear uncertain systems (BONUS) algorithm which dramatically decreases the computational requirements of the stochastic optimization.

Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

2009-01-01

441

Onset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water dynamics from millimeters to meters  

NASA Astrophysics Data System (ADS)

Estimation of water uptake by plants and subsequent water stress are complicated by the need to resolve the soil-plant hydrodynamics at scales ranging from millimeters to meters. Using a simplified homogenization technique, the three-dimensional (3-D) soil water movement dynamics can be reduced to solving two 1-D coupled Richards' equations, one for the radial water movement toward rootlets (mesoscale, important for diurnal cycle) and a second for vertical water motion (macroscale, relevant to interstorm timescales). This approach allows explicit simulation of known features of root uptake such as diurnal hysteresis in canopy conductance, hydraulic lift, and compensatory root water uptake during extended drying cycles. A simple scaling analysis suggests that the effectiveness of the hydraulic lift is mainly controlled by the root vertical distribution, while the soil moisture levels at which hydraulic lift is most effective is dictated by soil hydraulic properties and surrogates for atmospheric water vapor demand.

Siqueira, Mario; Katul, Gabriel; Porporato, Amilcare

2008-01-01

442

Nutrient abatement potential and abatement costs of waste water treatment plants in the Baltic Sea region.  

PubMed

We assess the physical potential to reduce nutrient loads from waste water treatment plants in the Baltic Sea region and determine the costs of abating nutrients based on the estimated potential. We take a sample of waste water treatment plants of different size classes and generalize its properties to the whole population of waste water treatment plants. Based on a detailed investment and operational cost data on actual plants, we develop the total and marginal abatement cost functions for both nutrients. To our knowledge, our study is the first of its kind; there is no other study on this issue which would take advantage of detailed data on waste water treatment plants at this extent. We demonstrate that the reduction potential of nutrients is huge in waste water treatment plants. Increasing the abatement in waste water treatment plants can result in 70 % of the Baltic Sea Action Plan nitrogen reduction target and 80 % of the Baltic Sea Action Plan phosphorus reduction target. Another good finding is that the costs of reducing both nutrients are much lower than previously thought. The large reduction of nitrogen would cost 670 million euros and of phosphorus 150 million euros. We show that especially for phosphorus the abatement costs in agriculture would be much higher than in waste water treatment plants. PMID:23996505

Hautakangas, Sami; Ollikainen, Markku; Aarnos, Kari; Rantanen, Pirjo

2014-04-01

443

Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses  

NASA Astrophysics Data System (ADS)

In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these unpredictable rainfall conditions, plant hydraulic traits (xylem and stomatal response to water availability) and morphological features (leaf and sapwood areas) must be coordinated - thus providing an ecohydrological interpretation of observed coordination (or homeostasis) among hydraulic traits. Moreover, the combinations of hydraulic traits and responses to drought that are optimal are found to depend on both total rainfall and its distribution during the growing season. Both drier conditions and more intense rainfall events interspaced by longer dry periods favor plants with high resistance to cavitation and delayed stomatal closure as soils dry. In contrast, plants in mesic conditions benefit from cavitation prevention through earlier stomatal closure. The proposed ecohydrological optimality criteria can be used as analytical tools to interpret variability in plant water use and predict trends in plant productivity and species composition under future climates.

Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

2013-12-01

444

Evaluation of coal-gasification - combustion-turbine power plants emphasizing low water consumption  

Microsoft Academic Search

A cost and performance study was made of several integrated power plants using coal gasification technology now in advanced development and combustion turbines for power generation. The principal emphasis was placed on studying plants using air cooling and comparing costs and performance of those plants with water-cooled coal gasification-combined-cycle (GCC) and conventional coal-fired power plants. The major objective was to

R. Cavazo; A. B. Clemmer; J. A. de la Mora; J. R. Grisso; H. W. Klumpe; R. E. Meissner; A. Musso; T. R. Roszkowski

1982-01-01

445

RESPONSES OF WETLAND PLANTS TO EFFLUENTS IN WATER & SEDIMENT  

EPA Science Inventory

Responses of two wetland vascular plants, Echinochloa crusgalli and Sesbania macrocarpa, exposed to effluents from a coke plant, a pulp mill, a wastewater treatment plant, and the herbicide, hexazinone, were measured in three types of tests: seed germination and early growth, see...

446

POWER PLANT COOLING WATER CHLORINATION IN NORTHERN CALIFORNIA  

EPA Science Inventory

A survey was conducted of chlorination practices at five power plants owned and operated by the Pacific Gas and Electric Company. Frequency and duration of chlorination varied significantly from plant to plant and was controlled analytically by the orthotolidine and/or amperometr...

447

Plant and soil resistance to water flow in faba bean (Vicia faba L. major Harz.)  

Microsoft Academic Search

An experiment was conducted to determine soil and plant resistance to water flow in faba bean under field conditions during\\u000a the growing season. During each sampling period transpiration flux and leaf water potential measured hourly were used with\\u000a daily measurements of root and soil water potential to calculate total resistance using Ohm's law analogy. Plant growth, root\\u000a density and soil

Celestino Ruggiero; Stefania De Pascale; Massimo Fagnano

1999-01-01

448

Plant hydraulic lift of soil water – implications for crop production and land restoration  

Microsoft Academic Search

Water more than other factors limits growth and productivity of terrestrial plants. Strategies of plants to cope with soil\\u000a drought include hydraulic redistribution of water via roots from moist to dry soil. During periods of drought, water may be\\u000a transported upward through root systems from moister subsurface to dry surface soil by a process known as “hydraulic lift”\\u000a (HL). On

Hans-Holger Liste; Jason C. White

2008-01-01

449

Investigating the Water Cycle: Using Plants to Study Evaporation  

NSDL National Science Digital Library

In this science activity, students investigate the water cycle by testing the water evaporated from leaves (transpiration) in a field experience. Students use elements of this information to track the water cycle through it's various stages.

450

A laser-induced fluorescence study of OH desorption from Pt(111) during oxidation of hydrogen in O2 and decomposition of water  

NASA Astrophysics Data System (ADS)

The desorption of OH radicals from Pt(111) at high temperature, ?1000 K, during the water formation (H2+1/2 O2?H2O) and water decomposition reactions, respectively, was investigated using the laser-induced fluorescence technique. The results are compared with corresponding data from our laboratory for polycrystalline Pt. The OH desorption rate in H2+O2 at 1-100 mTorr total pressure has its maximum at 8%-9% relative H2 concentration for surface temperatures between 1100 and 1400 K. With H2 replaced by D2, the OD desorption rate maximizes at somewhat higher relative hydrogen content. The apparent activation energy for OH desorption increases from about 1.4 eV at low relative hydrogen concentration to about 2.0 eV at hydrogen contents of 25% or more. For the water decomposition reaction, the apparent activation energy for OH desorption was found to be 1.7±0.2 eV at 0.5 Torr and 1.9±0.2 eV at 1 Torr. These differences in apparent activation energies are primarily due to kinetic effects. The results are analyzed within a kinetic model previously developed by Hellsing et al. [J. Catal. 132, 210 (1991)], and are also compared with previous data for polycrystalline Pt. The kinetic model calculations give good overall agreement with the measured OH desorption rates as functions of temperature, H2/O2 mixture and H2O pressure, respectively. A nonuniqueness problem, with respect to the choice of kinetic parameters, is encountered in the simulation of the measured data; quite different sets of two of the kinetic constants, namely the activation energy for water formation (via OH+H?H2O) and the activation energy for OH desorption can reproduce the data as long as their difference is constant. This nonuniqueness problem, which is a consequence of the steady-state nature of the measurements, is analyzed and discussed in some detail, as are some apparent contradictions in the absolute values of reported kinetic constants in the literature. From this analysis two important conclusions are drawn. (i) The apparent contradictions in the literature about absolute values of activation energies for the water formation reaction and for OH-desorption may be less severe than believed or nonexistent. (ii) Coverage dependent activation energies must be considered and experimental exploration of such coverage dependencies are needed to create a firmer base for the kinetic modeling of the H2/O2 reaction on Pt.

Fridell, Erik; Elg, Alf-Peter; Rosén, Arne; Kasemo, Bengt

1995-04-01

451

Game theory approach to the analysis of inter-plant water integration in an eco-industrial park  

Microsoft Academic Search

Industrial water conservation is an important adaptation to the effects of climate change. In addition to water conservation within individual plants, wastewater can be reused\\/recycled among different companies through inter-plant water integration (IPWI) schemes. Such schemes are based on the concept of industrial ecology and industrial symbiosis, and can be used to achieve greater water savings than when water conservation

Irene Mei Leng Chew; Raymond R. Tan; Dominic Chwan Yee Foo; Anthony Shun Fung Chiu

2009-01-01

452

Stomatal Responses to Water Stress and to Abscisic Acid in Phosphorus-Deficient Cotton Plants  

PubMed Central

Cotton (Gossypium hirsutum L.) plants were grown in sand culture on nutrient solution containing adequate or growth-limiting levels of P. When water was withheld from the pots, stomata of the most recently expanded leaf closed at leaf water potentials of approximately ?16 and ?12 bars in the normal and P-deficient plants, respectively. Pressure-volume curves showed that the stomata of P-deficient plants closed when there was still significant turgor in the leaf mesophyll. Leaves of P-deficient plants accumulated more abscisic acid (ABA) in response to water stress, but the difference was evident only at low water potentials, after initiation of stomatal closure. In leaves excised from unstressed plants, P deficiency greatly increased stomatal response to ABA applied through the transpiration stream. Kinetin blocked most of this increase in apparent sensitivity to ABA. The effect of P nutrition on stomatal behavior may be related to alterations of the balance between ABA and cytokinins. PMID:16663851

Radin, John W.

1984-01-01

453

Impacts of oil sands process water on fen plants: implications for plant selection in required reclamation projects.  

PubMed

Fen plant growth in peat contaminated with groundwater discharges of oil sands process water (OSPW) was assessed in a greenhouse over two growing seasons. Three treatments (non-diluted OSPW, diluted OSPW and rainwater) were tested on five vascular plants and four mosses. All vascular plants tested can grow in salinity and naphthenic acids levels currently produced by oil sands activity in northwestern Canada. No stress sign was observed after both seasons. Because of plant characteristics, Carex species (C. atherodes and C. utriculata) and Triglochin maritima would be more useful for rapidly restoring vegetation and creating a new peat-accumulating system. Groundwater discharge of OSPW proved detrimental to mosses under dry conditions and ensuring adequate water levels would be crucial in fen creation following oil sands exploitation. Campylium stellatum would be the best choice to grow in contaminated areas and Bryum pseudotriquetrum might be interesting as it has spontaneously regenerated in all treatments. PMID:22575093

Pouliot, Rémy; Rochefort, Line; Graf, Martha D

2012-08-01

454

How the soil-root interface affects water availability to plants  

Microsoft Academic Search

Water supply to roots is essential for plant life. To sustain the root water uptake, a continuous liquid phase has to be maintained at the interface between soil and roots. Gaps between soil and roots may interrupt the liquid-phase continuity across the soil-root interface, acting as capillary barriers for the water flow. Additionally, due to the radial geometry of the

Andrea Carminati; Ahmad Moradi

2010-01-01

455

A simulation model of plant water relations and production in the alpine tundra, Colorado  

Microsoft Academic Search

A model to predict the daily courses of leaf resistance, leaf water potential, transpiration, leaf temperature and net photosynthesis based on soil-plant-atmosphere continuum and energy budget concepts is presented. The principle water relations parameters required by the model are the minimum leaf resistance, the response curves of leaf resistance to light, temperature, and leaf water potential, and the relationship between

James R. Ehleringer; Philip C. Miller

1975-01-01

456

Treatment efficiency and economic benefit of Zartech poultry slaughter house waste water treatment plant, Ibadan, Nigeria  

Microsoft Academic Search

The efficiency of the poultry wastewater treatment plant of Zartech Limited, Ibadan, Nigeria, was assessed based on percentage reduction of the various water contaminants while the unit cost of treated water was compared with that supplied through tankers. Wastewater and treated water samples were respectively collected from the points of generation and release after treatment for laboratory analysis for biochemical

Yahaya Mijinyawa; Nurudeen Samuel Lawal

457

Bacteriological Changes Associated with Granular Activated Carbon in a Pilot Water Treatment Plant  

Microsoft Academic Search

Bacteriological analysis were performed on collected water samples from a conventional water treatment pilot plant in Cincinnati, Ohio in which granular activated carbon (GAC) has been used as the final process to assess the impact of GAC on the bacteriological quality and incidence of antibiotic resistant bacteria in water produced. Heterotrophic bacterial counts (HPC) at 20 °C was stabilized at

Helmy Tawfik El-Zanfaly; Donald J. Reasoner; Edwin E. Geldreich

1998-01-01

458

Water Use and Drought Resistance of Turfgrass and Ornamental Landscape Plant Species  

ERIC Educational Resources Information Center

In 2005, turfgrass was estimated to cover approximately 20 million ha of urbanized land. That area is increasing with rapid urbanization, stressing the importance of water conservation in the lawn and landscape industry. Turfgrasses have been identified for replacement by presumably more water-efficient ornamental plant species to conserve water

Domenghini, Jacob Cody

2012-01-01

459

Making the most of increased water flow: Expanding the Devil Canyon hydro plant  

Microsoft Academic Search

Amidst the longest California drought on record, work is proceeding to bring additional water to the southern part of the state. With extra water comes an opportunity for increasing hydro - one project is underway to add 160 MW of power to an existing 120-MW plant. The California State Department of Water Resources (DWR) completed the initial phase of its

B. E. DePuy; R. C. Butler

1992-01-01

460

Influence of paclobutrazol on water consumption and plant performance of Arbutus unedo seedlings  

Microsoft Academic Search

The purpose of this study was to examine the effect of paclobutrazol on the water consumption, plant water relations, gas exchange and development of strawberry tree seedlings (Arbutus unedo L.), to evaluate water resource management. Seedlings (8cm in height) were subjected to a single drench of 60 or 100mg of paclobutrazol and pot-grown in a greenhouse for 4 months. Untreated

Alejandra Navarro; M Sánchez-Blanco; Sebastián Bañon

2007-01-01

461

Infield monitoring of cleaning efficiency in waste water treatment plants using two phenol-sensitive biosensors  

Microsoft Academic Search

Two amperometric biosensors based on the enzymes cellobiose dehydrogenase (CDH) and quinoprotein-dependent glucose dehydrogenase (GDH), have been applied for monitoring the phenolic content in water samples, collected at different stages of a waste water treatment process, thus representing different cleaning levels of two waste water treatment plants (WWTPs). The biosensor measurements were performed in-field, compared with the results obtained by

Catalin Nistor; Andreas Rose; Marinella Farré; Leonard Stoica; Ulla Wollenberger; Tautgirdas Ruzgas; Dorothea Pfeiffer; Damià Barceló; L