We investigated the anaerobic biodegradation of mono- and dichlorophenol isomers by fresh (unacclimated) sludge and by sludge acclimated to either 2-chlorophenol, 3-chlorophenol, or 4-chlorophenol. Biodegradation was evaluated by monitoring substrate disappearance and, in selected cases, production of 14CH4 from labeled substrates. In ...
PubMed Central
An investigation was made of the anaerobic biodegradation of mono- and dichlorophenol isomers by fresh (unacclimated) sludge and by sludge acclimated to either 2-chlorophenol, 3-chlorophenol, or 4-chlorophenol. Biodegradation was evaluated by monitoring substrate disappearance and, in selected cases, production of /sup 14/CH/sub 4/ ...
Energy Citations Database
Carboxymethyl tartronate (CMT) was shown to be biodegradable in bench-scale activated sludge reactors. After initial exposure to CMT in continuous flow systems an acclimation period of 14 weeks was necessary before efficient degradation occurred. Once acclimated to CMT the biomas...
EPA Science Inventory
The paper describes tests performed in order to evaluate the fate of aqueous organic hazardous waste compounds in the activated sludge process. Gas, liguid, and waste solids samples were taken from acclimated activated sludge systems to determine amounts that were volatilized, bi...
The period of acclimatisation prior to the biodegradation of nitrilotriacetic acid in an activated sludge pilot plant was studied in a series of experiments. The effects of low and high influent heavy metals concentrations upon acclimatisation are reported.
Biodegradation of 75 and 100 mg/l of 2,4-dinitrophenol (DNP) by activated sludge acclimated in a Sequencing Batch Reactor (SBR) consistently required less than 6 hours although a lag at the beginning of every 48-hour SBR cycle was observed. Other investigators have reported that DNP levels of 100 mg/l and higher are significantly toxic ...
PubMed
This work established a mathematical model that formulated degrader formation by conversion of indigenous microbial cells. Degrader conversion is attributed to genetic induction whose force is dependent on the strength of acclimating xenobiotic and the amount of indigenous cells. After successful conversion, which requires an amount of time proportionate to the lag, degraders ...
The biodegradability of toluene diamine (TDA) which has been regarded as a "recalcitrant compound" was examined in activated sludges. In this study, a microorganic-enzyme system which metabolized TDA was obtained by acclimating the activated sludge with aniline and TDA. In the ...
Antisera were raised against nine strains which had been isolated from phenol-acclimated oil refinery activated sludge. Although several antisera reacted significantly with the activated sludge during a period of adaptation to phenol, only an antiserum against one of the isolates, Alcaligenes ...
The paper describes tests performed in order to evaluate the fate of aqueous organic hazardous-waste compounds in the activated sludge process. Gas, liguid, and waste-solids samples were taken from acclimated activated-sludge systems to determine amounts that were volatilized, biodegraded, and associated with the ...
The response of a laboratory-scale activated sludge unit to diethyl phthalate, dimethyl phthalate, 2,4-dinitrophenol, 2,4-dimethylphenol and 4-nitrophenol was examined. The system tolerated phthalate esters well and the acclimation was quick. The response of the system to stepwise increasing concentrations of other hazardous compounds ...
The distribution and phylogenetic affiliations of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-degrading denitrifying bacteria in activated sludge were studied by a polyphasic approach including culture-independent biomarker and molecular analyses as well as cultivation methods. A total of 23 strains of PHBV-degrading denitrifiers were isolated from ...
This study compared the effect of four pure carbon supplements on biological denitrification to a liquor derived as a by-product from the wet oxidation (WO) of waste activated sludge. Sequencing batch reactors were used to acclimate sludge biomass, which was used in batch assays. Acetate, WO liquor and ...
The biodegradation and inhibition kinetics of a commercial nonylphenol ethoxylate formulation were modelled for an activated sludge system fed with a synthetic substrate and nonylphenol ethoxylate mixture. Kinetic and stoichiometric coefficients of the proposed activated sludge model were obtained by employing ...
The objectives of the present work were: (i) to analyze the capacity of activated sludge to reduce hexavalent chromium using different carbon sources as electron donors in batch reactors, (ii) to determine the relationship between biomass growth and the amount of Cr(VI) reduced considering the effect of the nitrogen to carbon source ratio, and (iii) to ...
Substrate removal and bacterial growth kinetics, oxygen requirements, and the effects of temperature, pH, salinity, and nutrients on bacterial activities were investigated for the removal of phenol and methanol spills by acclimated biological sludge or bacteria. The results were evaluated statistically. Either in-situ methods or ...
The impacts of bisphenol A- imprinted polymeric microspheres (MIPMs) on the biodegradation of bisphenol A by acclimated activated sludge were studied. Due to the selective adsorption of MIPMs to bisphenol A (BPA) and its analogues, addition of MIPMs to activated sludge increased levels of BPA ...
... MICROBIOLOGIC STUDIES OF THE ACTIVATED SLUDGE PROCESS ... MICROBIOLOGIC STUDIES OF THE ACTIVATED SLUDGE PROCESS ...
DTIC Science & Technology
The activated sludge process continues to be the preferred secondary wastewater treatment method for removal of biodegradable, soluble, organic matter. The mode of operation consists of contacting the substrate organic matter with a large population of viable microorganisms in an aerobic environment. The development of this mixed liquor population during ...
Contents: List of tables; The atlas; Information from Microscopic Examination of Activated Sludge; Microscopic Appearance of Sludge; Description of Sludge Types.
National Technical Information Service (NTIS)
... and aquifers. Anaerobic digester sludge acclimated to PCP removes chlorines from all positions of PCP, but the ortho chlorines ...
Acclimated biological cultures were developed from activated sludge taken from coke plant biological waste treatment facilities. These cultures are capable of degrading potassium thiocyanate from an original concentration of 2000 mg/l SCN to less than 1 m...
When residuals from intensive swine production are released without adequate treatment, they represent a significant environmental problem that can cause great environmental impact in rivers and water bodies. Although treatment technologies are well developed for removal of organic load from high-st...
Technology Transfer Automated Retrieval System (TEKTRAN)
Response to shock loads of phenol was studied in an activated sludge pilot system with constant recycle sludge concentration. Results were compared to a predictions model. An increase from 500 to 1000 mg/L was tolerated well, which agreed with model predictions. A shock increase from 1000 to 2000 mg/L resulted in a specific growth rate ...
INTRODUCTION: This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20�mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge. MATERIALS AND ...
Unacclimated and acclimated activated sludges were examined for their ability to degrade 4-CP (4-chlorophenol) in the presence and absence of a readily growing substrate using aerobic batch reactors. The effects of 4-CP on the {mu} (specific growth rate), COD removal efficiency, Y (yield coefficient), and q (specific substrate ...
