Science.gov

Sample records for chlorine 40

  1. 40 CFR 704.45 - Chlorinated terphenyl.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... means the percent by weight of chlorine for each isomer (ortho, meta, and para). (3) Isomeric ratio... chlorinated terphenyl. (4) A description of the isomeric ratio and extent of chlorination of the...

  2. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  3. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  4. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  5. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  6. 40 CFR 704.43 - Chlorinated naphthalenes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the chlorine atom(s) on the naphthalene. (4) Polychlorinated biphenyl means any chemical substance that is limited to the biphenyl molecule and that has been chlorinated to varying degrees. (5)...

  7. Chlorine Inactivation of Adenovirus Type 40 and Feline Calicivirus

    PubMed Central

    Thurston-Enriquez, Jeanette A.; Haas, Charles N.; Jacangelo, Joseph; Gerba, Charles P.

    2003-01-01

    Ct values, the concentration of free chlorine multiplied by time of contact with virus, were determined for free-chlorine inactivation experiments carried out with chloroform-extracted (dispersed) and non-chloroform-extracted (aggregated) feline calicivirus (FCV), adenovirus type 40 (AD40), and polio virus type 1 (PV-1). Experiments were carried out with high and low pH and temperature conditions. Ct values were calculated directly from bench-scale free-chlorine inactivation experiments and from application of the efficiency factor Hom model. For each experimental condition, Ct values were higher at pH 8 than at pH 6, higher at 5°C than at 15°C, and higher for dispersed AD40 (dAD40) than for dispersed FCV (dFCV). dFCV and dAD40 were more sensitive to free chlorine than dispersed PV-1 (dPV-1). Cts for 2 log inactivation of aggregated FCV (aFCV) and aggregated PV-1 (aPV-1) were 31.0 and 2.8 orders of magnitude higher than those calculated from experiments carried out with dispersed virus. Cts for 2 log inactivation of dFCV and dAD40 in treated groundwater at 15°C were 1.2 and 13.7 times greater than in buffered-demand-free (BDF) water experiments at 5°C. Ct values listed in the U.S. Environmental Protection Agency (EPA) Guidance Manual were close to, or lower than, Ct values generated for experiments conducted with dispersed and aggregated viruses suspended in BDF water and for dispersed viruses suspended in treated groundwater. Since the state of viruses in water is most likely to be aggregated and associated with organic or inorganic matter, reevaluation of the EPA Guidance Manual Ct values is necessary, since they would not be useful for ensuring inactivation of viruses in these states. Under the tested conditions, dAD40, dFCV, aFCV, dPV-1, and aPV-1 particles would be inactivated by commonly used free chlorine concentrations (1 mg/liter) and contact times (60 to 237 min) applied for drinking water treatment in the United States. PMID:12839771

  8. Chlorine

    Integrated Risk Information System (IRIS)

    Chlorine ; CASRN 7782 - 50 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  9. Chlorine

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical chlorine, produced in small quantities in the laboratory, is presented. The profile summarizes physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  10. Chlorine

    SciTech Connect

    Talmage, Sylvia Smith

    2009-01-01

    Following a brief description of the use of chlorine as a chemical warfare agent in World War I, this chapter summarizes physical and chemical data and recent clinical and controlled laboratory studies on the irritant and lethal effects of chlorine. The mechanism of toxicity for both irritation and lethal effects is described. The mathematical relationship between concentration and exposure duration for a set endpoint is given for both an irritancy response and mortality. This information can be used to assist in time-scaling for the set endpoint to other exposure durations. Risk assessment addresses the potential for greater effects in sensitive populations such as asthmatics. A concentration of 0.5 ppm for up to 8 hours is a no-adverse-effect concentration in most sensitive subjects; whereas, a concentration of 1.0 ppm induces some sensory irritation and transient changes in respiratory tract airflow parameters. Treatment and intervention of exposed individuals is dependent upon symptoms

  11. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Chlorine gas; exemptions from the requirement of a tolerance. 180.1095 Section 180.1095 Protection of Environment ENVIRONMENTAL PROTECTION... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance....

  12. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Chlorine gas; exemptions from the requirement of a tolerance. 180.1095 Section 180.1095 Protection of Environment ENVIRONMENTAL PROTECTION... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance....

  13. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Chlorine gas; exemptions from the requirement of a tolerance. 180.1095 Section 180.1095 Protection of Environment ENVIRONMENTAL PROTECTION... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance....

  14. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Chlorine gas; exemptions from the requirement of a tolerance. 180.1095 Section 180.1095 Protection of Environment ENVIRONMENTAL PROTECTION... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance....

  15. 40 CFR 180.1095 - Chlorine gas; exemptions from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Chlorine gas; exemptions from the requirement of a tolerance. 180.1095 Section 180.1095 Protection of Environment ENVIRONMENTAL PROTECTION... Exemptions From Tolerances § 180.1095 Chlorine gas; exemptions from the requirement of a tolerance....

  16. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Standards to control hydrogen chloride... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine...

  17. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Standards to control hydrogen chloride... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine...

  18. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Standards to control hydrogen chloride... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine...

  19. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Standards to control hydrogen chloride... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine...

  20. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Standards to control hydrogen chloride... Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. (a) General. The owner or operator must comply with the hydrogen chloride (HCl) and chlorine...

  1. 40 CFR 63.1215 - What are the health-based compliance alternatives for total chlorine?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alternatives for total chlorine? 63.1215 Section 63.1215 Protection of Environment ENVIRONMENTAL PROTECTION... Combustors Other § 63.1215 What are the health-based compliance alternatives for total chlorine? (a) General... chlorine under the procedures prescribed in this section for your hazardous waste combustors other...

  2. 40 CFR 63.1215 - What are the health-based compliance alternatives for total chlorine?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alternatives for total chlorine? 63.1215 Section 63.1215 Protection of Environment ENVIRONMENTAL PROTECTION... Waste Combustors Other § 63.1215 What are the health-based compliance alternatives for total chlorine... total chlorine under the procedures prescribed in this section for your hazardous waste combustors...

  3. 40 CFR 63.1215 - What are the health-based compliance alternatives for total chlorine?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alternatives for total chlorine? 63.1215 Section 63.1215 Protection of Environment ENVIRONMENTAL PROTECTION... Waste Combustors Other § 63.1215 What are the health-based compliance alternatives for total chlorine... total chlorine under the procedures prescribed in this section for your hazardous waste combustors...

  4. 40 CFR 63.1215 - What are the health-based compliance alternatives for total chlorine?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alternatives for total chlorine? 63.1215 Section 63.1215 Protection of Environment ENVIRONMENTAL PROTECTION... Combustors Other § 63.1215 What are the health-based compliance alternatives for total chlorine? (a) General... chlorine under the procedures prescribed in this section for your hazardous waste combustors other...

  5. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration...

  6. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING...

  7. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING...

  8. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration...

  9. 40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide...

  10. 40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide...

  11. 40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide...

  12. 40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide...

  13. 40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide...

  14. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system...

  15. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must...

  16. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must...

  17. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system...

  18. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must...

  19. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system...

  20. 40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... must I use to demonstrate initial compliance with chlorine and hydrochloric acid emission limits? 63... chlorine and hydrochloric acid emission limits? (a) You must conduct each performance test that applies to... the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you...

  1. 40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... must I use to demonstrate initial compliance with chlorine and hydrochloric acid emission limits? 63... chlorine and hydrochloric acid emission limits? (a) You must conduct each performance test that applies to... the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you...

  2. 40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... must I use to demonstrate initial compliance with chlorine and hydrochloric acid emission limits? 63... chlorine and hydrochloric acid emission limits? (a) You must conduct each performance test that applies to... the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you...

  3. 40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... must I use to demonstrate initial compliance with chlorine and hydrochloric acid emission limits? 63... chlorine and hydrochloric acid emission limits? (a) You must conduct each performance test that applies to... the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you...

  4. 40 CFR 63.9914 - What test methods and other procedures must I use to demonstrate initial compliance with chlorine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... must I use to demonstrate initial compliance with chlorine and hydrochloric acid emission limits? 63... chlorine and hydrochloric acid emission limits? (a) You must conduct each performance test that applies to... the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you...

  5. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 261 as EPA Hazardous Wastes Numbers K174, and K175, soil and debris contaminated with these... 40 CFR 268.45 Table 1 unless the waste is placed in: (1) A Subtitle C monofill containing only K175 wastes that meet all applicable 40 CFR 268.40 treatment standards; or (2) A dedicated Subtitle C...

  6. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 261 as EPA Hazardous Wastes Numbers K174, and K175, soil and debris contaminated with these... 40 CFR 268.45 Table 1 unless the waste is placed in: (1) A Subtitle C monofill containing only K175 wastes that meet all applicable 40 CFR 268.40 treatment standards; or (2) A dedicated Subtitle C...

  7. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 261 as EPA Hazardous Wastes Numbers K174, and K175, soil and debris contaminated with these... 40 CFR 268.45 Table 1 unless the waste is placed in: (1) A Subtitle C monofill containing only K175 wastes that meet all applicable 40 CFR 268.40 treatment standards; or (2) A dedicated Subtitle C...

  8. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 261 as EPA Hazardous Wastes Numbers K174, and K175, soil and debris contaminated with these... 40 CFR 268.45 Table 1 unless the waste is placed in: (1) A Subtitle C monofill containing only K175 wastes that meet all applicable 40 CFR 268.40 treatment standards; or (2) A dedicated Subtitle C...

  9. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR part 261 as EPA Hazardous Wastes Numbers K174, and K175, soil and debris contaminated with these... 40 CFR 268.45 Table 1 unless the waste is placed in: (1) A Subtitle C monofill containing only K175 wastes that meet all applicable 40 CFR 268.40 treatment standards; or (2) A dedicated Subtitle C...

  10. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  11. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  12. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  13. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  14. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  15. Chlorine dioxide

    Integrated Risk Information System (IRIS)

    Chlorine dioxide ; CASRN 10049 - 04 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  16. Chlorine cyanide

    Integrated Risk Information System (IRIS)

    Chlorine cyanide ; CASRN 506 - 77 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  17. Chlorine-36 in fossil rat urine: An archive of cosmogenic nuclide deposition during the past 40,000 years

    SciTech Connect

    Plummer, M.A.; Phillips, F.M.; Fabryka-Martin, J.

    1997-07-25

    Knowledge of the production history of cosmogenic nuclides, which is needed for geological and archaeological dating, has been uncertain. Measurements of chlorine-36/chlorine ({sup 36}Cl/Cl) ratios in fossil packrat middens from Nevada that are radiocarbon-dated between about 38 thousand years ago (ka) and the present showed that {sup 36}Cl/Cl ratios were higher by a factor of about 2 before {approx} 11 ka. This raises the possibility that cosmogenic production rates just before the close of the Pleistocene were up to 50% higher than is suggested by carbon-14 calibration data. The discrepancy could be explained by addition of low-carbon-14 carbon dioxide to the atmosphere during that period, which would have depressed atmospheric radiocarbon activity. Alternatively, climatic effects on {sup 36}Cl deposition may have enhanced the {sup 36}Cl/Cl ratios. 49 refs., 3 figs.

  18. Chlorine Clues

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This plot shows that levels of the element chlorine rise dramatically in the deeper rocks lining the walls of the crater dubbed 'Endurance.' The data shown here were taken by the Mars Exploration Rover Opportunity's alpha particle X-ray spectrometer at Endurance and 'Eagle Crater,' the site where Opportunity first landed at Meridiani Planum.

    Opportunity has been inching down the walls of Endurance Crater, investigating distinct layers of rock as it goes for clues to Mars' buried past. The various Endurance layers have been informally labeled 'A' through 'F.' Targets within these layers are listed on the graph along with previous targets from Eagle Crater. All the rocks listed here were observed after they had been drilled by the rover's rock abrasion tool.

    The observations indicate that the elements making up the shallow rock layers of Endurance Crater resemble those of Eagle, while the deeper layers of Endurance possess increasingly higher concentrations of the element chlorine.

    Opportunity will continue to roll deeper into Endurance to see if this puzzling trend continues. Scientists hope the new data will help them figure out how the presence of chlorine fits into the history of water at Endurance Crater.

  19. REVIEW OF CHLORINATED PHENOLS

    EPA Science Inventory

    The chlorinated phenols are a group of 19 isomers composed of phenol with substituted chlorines. These chemicals are readily soluble in organic solvents but only slightly soluble in water, except for the chlorophenate salts. Chlorophenols with less than 3 chlorines are not used e...

  20. The Chlorination Quandary

    ERIC Educational Resources Information Center

    Josephson, Julian

    1978-01-01

    Current use of chlorination technology to disinfect water supplies can cause the production of undesirable products, among them chloroform and chlorobenzene. Alternatives to this methodology include the use of ozone, chlorine dioxide, and bromine chloride in place of chlorine. Presently, the methods are feasible in developed countries only. (MA)

  1. First spectra of chlorine, bromine, and iodine in the 1.8- to 4.0-micron region.

    NASA Technical Reports Server (NTRS)

    Humphreys, C. J.; Paul, E., Jr.

    1972-01-01

    Use of liquid-nitrogen-cooled lead sulfide detectors to extend observations of the first spectra of the halogens in the infrared region as far as 4.0 microns. Descriptions, comprising wavelengths, wave numbers, intensities, and classifications, are presented that serve to close the gap between the upper wavelength limit of the detailed published analyses of these spectra at about 2.5 microns and the groups of recently classified lines near 4 microns, and also to report newly observed lines in the 1.8- to 2.5-micron region made accessible by detectors of improved response characteristics. Listed wavelengths of observed and identified lines are calculated from established values of the energy levels. The descriptions should facilitate the identification of halogen lines in mixed spectra excited in electrodeless tubes containing halogen compounds.

  2. Hydrochloric Acid and the Chlorine Budget of the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Webster, C.; May, R.; Jaegle, L.; Hu, H.; Sander, S.; Gunson, M.; Toon, G.; Russell, J., III; Stimpfle, R.; Koplow, J.; Salawitch, R.; Michelsen, H.

    1994-01-01

    Concentrations of hc1 measured in the lower stratosphere in 1993 by the ALIAS instrument on the ER-2 aircraft reveal that only 40% of inorganic chlorine (CL sub y, inferred from in situ measurements of organic chlorinated source gases) is present as HC1, significantly lower than model predictions.

  3. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MRDL (mg/L) Chlorine 4.0 (as Cl2). Chloramines 4.0 (as Cl2). Chlorine dioxide 0.8 (as ClO2). (b... chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and using chlorine dioxide as...

  4. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MRDL (mg/L) Chlorine 4.0 (as Cl2). Chloramines 4.0 (as Cl2). Chlorine dioxide 0.8 (as ClO2). (b... chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and using chlorine dioxide as...

  5. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MRDL (mg/L) Chlorine 4.0 (as Cl2). Chloramines 4.0 (as Cl2). Chlorine dioxide 0.8 (as ClO2). (b... chlorine dioxide as a disinfectant or oxidant must comply with the chlorine dioxide MRDL beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons and using chlorine dioxide as...

  6. Aqueous chlorination of resorcinol

    USGS Publications Warehouse

    Heasley, V.L.; Burns, M.D.; Kemalyan, N.A.; Mckee, T.C.; Schroeter, H.; Teegarden, B.R.; Whitney, S.E.; Wershaw, R. L.

    1989-01-01

    An investigation of the aqueous chlorination (NaOCl) of resorcinol is reported. The following intermediates were detected in moderate to high yield at different pH values and varying percentages of chlorination: 2-chloro-, 4-chloro-, 2,4-dichloro-, 4,6-dichloro- and 2,4,6-trichlororesorcinol. Only trace amounts of the intermediates were detected when the chlorination was conducted in the presence of phosphate buffer. This result has significant implications since resorcinol in phosphate buffer has been used as a model compound in several recent studies on the formation of chlorinated hydrocarbons during chlorination of drinking water. Relative rates of chlorination were determined for resorcinol and several of the chlorinated resorcinols. Resorcinol was found to chlorinate only three times faster than 2,4,6-trichlororesorcinol. The structure 2,4,6-trichlororesorcinol was established as a monohydrate even after sublimation. A tetrachloro or pentachloro intermediate was not detected, suggesting that the ring-opening step of such an intermediate must be rapid. ?? 1989.

  7. Water Treatment Technology - Chlorination.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on chlorination provides instructional materials for nine competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purpose and process of chlorination, chlorine…

  8. Inhalation of chlorine gas.

    PubMed

    Williams, J G

    1997-11-01

    The clinical features of acute chlorine gas inhalation, and its management are reviewed. Current medical views on the chronic effects of an acute overwhelming exposure on lung function (reactive airways dysfunction syndrome), and the more controversial field of lung disease secondary to repeated inhalations of lower concentrations of chlorine gas are discussed. PMID:9519180

  9. CHLORINATED SOLVENT PLUME CONTROL

    EPA Science Inventory

    This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE).

  10. Breathing with chlorinated solvents

    SciTech Connect

    McCarty, P.L.

    1997-06-06

    Chlorinated solvents are effective cleaners and in the past dirted solvents were dumped into landfills, stored in tanks that often leaked, or spilled. As a result the most common contaminants of organic groundwater at hazardous waste sites are the two major chlorinated solvents - tetrachloroethylene (PCE) and trichloroethylene (TCE). Both are suspected carcinogens and both are highly resistant to biodegradation. Now however, there is a report of a bacterium that can remove all of the chlorine atoms from both by halorespiration to form ethene, an innocuous end product. This article goes on to discuss the background of biodegradation of chlorinated compounds, why it is so difficult, and what the future is in this area. 9 refs., 1 fig.

  11. Bugs digest chlorinated organics

    SciTech Connect

    Not Available

    1993-02-01

    This article describes a new bioreactor that uses a consortium of aerobic bacteria to biodegrade chlorinated aromatic hydrocarbons. Methanotrophic bacteria are cultivated for their MMO enzyme. After the MMO enzyme breaks down the chlorinated organics by oxidation, non-methanotrophic bacteria consume the byproducts. Pilot-scale testing has demonstrated successful treatment of groundwater containing coal-tar constituents, toluene, trichloroethylene, vinyl chlorides, chlorobenzene, and methyl methacrylate from three Superfund sites.

  12. Review of chlorinated phenols

    SciTech Connect

    Exon, J.H.

    1984-12-01

    The chlorinated phenols are a group of 19 isomers composed of phenol with substituted chlorines. These chemicals are readily soluble in organic solvents but only slightly soluble in water, except for the chlorophenate salts. Chlorophenols with less than 3 chlorines are not used extensively except in the production of higher chlorophenols and chlorophenyloxyacetic acid herbicides. Pentachlorophenol and some tetrachlorophenols are used worldwide, primarily as wood preservatives or fungicides. Residues of chlorophenols have been found worldwide in soil, water and air samples, in food products, and in human and animal tissues and body fluids. Environmental contamination with these chemicals occurs from industrial effluents, agricultural runoff, breakdown of chlorophenyloxyacetic acid herbicides and hexachlorobenzene, and from spontaneous formation following chlorination of water for disinfection and deodorization. The acute toxicity of these chemicals is relatively low and little is known concerning their chronic effects. Chlorophenols have not been shown conclusively to be mutagens, teratogens or carcinogens. However, these compounds may act as promotors or cocarcinogens and the immune system is particularly sensitive to their toxic effects. Transplacental exposure to chlorophenols may result in embryotoxicity and abortion. The major mode of toxic action is as uncouplers of oxidative phosphorylation. The toxicity of chlorophenols decreases with decreasing chlorination. These chemicals are mild hepatotoxins and are stored mainly in hepatic and renal tissues.

  13. Percutaneous and oral absorption of chlorinated paraffins in the rat.

    PubMed

    Yang, J J; Roy, T A; Neil, W; Krueger, A J; Mackerer, C R

    1987-09-01

    Parallel percutaneous absorption studies of two 14C-labelled chlorinated paraffins (C18, 50-53% chlorination; C28, 47% chlorination) were carried out in the Sprague-Dawley rat. The dermally applied dose (66 mg/cm2) was approximately equivalent to 2.0 g/kg of body weight. An oral absorption study with the C18-chlorinated paraffin (0.5 g/kg) was carried out in rats for comparison. Less than 1% of the dermally applied dose of [1-14C]polychlorooctadecane (50-53% chlorination) and less than 0.1% of the applied dose of [14,15-14C]polychlorooctacosane (47% chlorination) were recovered in excreta, expired air and tissues after 96 hours. In contrast, approximately 86% of the orally administered dose of [1-14C]polychlorooctadecane (0.5 g/kg) was recovered. These results indicate that rat skin acts as an effective barrier to chlorinated paraffins containing eighteen or more carbons and more than 40% chlorine by weight. The oral absorption of the C18 chlorinated paraffin can be estimated to be nearly 100 times greater than its dermal absorption. Based on current toxicity results from rodent experiments and these present findings, chlorinated paraffins of the type tested would be expected to have little or no effect in animals as a result of dermal exposure. It is reasonable to assume that such chlorinated paraffins are unlikely to be systemically toxic to humans by skin contact under normal conditions of production and use. PMID:3686542

  14. Chlorine characterization and thermal behavior in MSW and RDF.

    PubMed

    Ma, Wenchao; Hoffmann, Gaston; Schirmer, Mattias; Chen, Guanyi; Rotter, Vera Susanne

    2010-06-15

    Chlorine, as a key element causing high temperature corrosion and low efficiency in waste-to-energy plants, and its thermal behavior has widely drawn attention. In this study, the chlorine content in eight fractions of municipal solid waste (MSW) was quantified and characterized using five analytical methods. The influence of the operating temperature, and fuel additives like sulfur and silica on the volatilization of chlorine in combustion process was also investigated. The results showed: these fractions cover a wide range of chlorine content from 0.1 wt.% in wood to >6 wt.% in non-packaging plastics (dry basis). Polyvinylchloride (PVC) from packaging, electrical wire insulation etc. in plastics and chloride salts (mainly NaCl) in kitchen waste are the main sources of organic and inorganic chlorine. The increase of the operating temperature from 700 degrees C to 1000 degrees C has more influence on the HCl formation for kitchen waste than that for PVC. Sulfur addition leads to 20-40% higher HCl formation rate in most fractions. Silica supports the chlorine release at relatively low temperatures between 700 degrees C and 850 degrees C. These findings enhance to understand the thermal behavior of chlorine in MSW and RDF (refuse derived fuel) in waste-to-energy plants and lead to the suggestions for a fuel management for waste derived fuels in order to avoid chlorine induced corrosion. PMID:20171781

  15. Chlorine: state of the art.

    PubMed

    Evans, Richard B

    2005-01-01

    Chlorine is a widely used industrial chemical. Individuals can be exposed to chlorine through transportation accidents, industrial exposures or misuse of domestic cleaners. While most exposed individuals recover normal pulmonary function, chlorine can cause a variety of lung injuries including pulmonary edema, restrictive lung disease, and obstructive disease, including Reactive Airways Dysfunction Syndrome. Residual effects of chlorine exposure are a function of intensity of exposure, minute ventilation during exposure, and host characteristics such as cigarette smoking and atopy. This monograph will summarize uses of chlorine, the potential for accidents, the mechanism of chlorine toxicity in the lung, and review acute and chronic effects of chlorine exposure on the lung, as well as systemic effects of massive chlorine exposure. PMID:16078037

  16. A Visible-Light-Induced α-H Chlorination of Alkylarenes with Inorganic Chloride under NanoAg@AgCl.

    PubMed

    Liu, Shouxin; Zhang, Qi; Li, Huiying; Yang, Yihua; Tian, Xia; Whiting, Andrew

    2015-06-26

    An efficient, photocatalytic chlorination of alkylarene α-H groups using NaCl/HCl as a chlorine source has been developed, which involves a radical mechanism under visible-light (including sunlight) conditions. A chlorine radical is proposed to be formed by an electron transfer from chloride ion to O2 in air through the bandgap hole of the semiconductor AgCl. The chlorination protocol is characterized by its use of natural sunlight or other visible light, mild conditions, cheap source of chlorine, green solvent, and high selectivity. The yield of benzylchloride is 95% with a toluene conversion as high as 40%, which rivals traditional chlorination methods. PMID:26061749

  17. Hydrodesulfurization of chlorinized coal

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Rohatgi, N. K. (Inventor)

    1983-01-01

    A method of desulfurization is described in which high sulfur coals are desulfurized by low temperature chlorinolysis of coal in liquid media, preferably water, followed by hydrodesulfurization at a temperature above 500 C. The coals are desulfurized to an extent of up to 90% by weight and simultaneously dechlorinated to a chlorine content below 0.1% by weight. The product coals have lower volatiles loss, lower oxygen and nitrogen content and higher fixed carbon than raw coals treated with hydrogen under the same conditions. Heating the chlorinated coal to a temperature above 500 C. in inert gas such as nitrogen results in significantly less desulfurization.

  18. Efficient photosensitization by a chlorin-polyoxometalate supramolecular complex.

    PubMed

    Yoon, Il; Kim, Jung Hwa; Li, Jia Zhu; Lee, Woo Kyoung; Shim, Young Key

    2014-01-01

    The 4:1 supramolecular complexed ionic salt between pyridinium chlorin and polyanionic [α-SiMo12O40](4-) exhibits significantly enhanced photodynamic activity against A549 cell lines because of increased singlet oxygen photogeneration through high cellular penetration and localization of the chlorin molecules on the ionic salt into the cancer cell. Confocal laser scanning microscopy images clearly represent a higher uptake and photodynamic effect of this supramolecular complex corresponding to the lower IC50 value compared to the free chlorin. PMID:24320629

  19. Reaction products of chlorine dioxide.

    PubMed Central

    Stevens, A A

    1982-01-01

    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

  20. Chlorination of lanthanum oxide.

    PubMed

    Gaviría, Juan P; Navarro, Lucas G; Bohé, Ana E

    2012-03-01

    The reactive system La(2)O(3)(s)-Cl(2)(g) was studied in the temperature range 260-950 °C. The reaction course was followed by thermogravimetry, and the solids involved were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The results showed that the reaction leads to the formation of solid LaOCl, and for temperatures above 850 °C, the lanthanum oxychloride is chlorinated, producing LaCl(3)(l). The formation of the oxychloride progresses through a nucleation and growth mechanism, and the kinetic analysis showed that at temperatures below 325 °C the system is under chemical control. The influence of diffusive processes on the kinetics of production of LaOCl was evaluated by studying the effect of the reactive gas flow rate, the mass of the sample, and the chlorine diffusion through the boundary layer surrounding the solid sample. The conversion curves were analyzed and fitted according to the Johnson-Mehl-Avrami description, and the reaction order with respect to the chlorine partial pressure was obtained by varying this partial pressure between 10 and 70 kPa. The rate equation was obtained, which includes the influence of the temperature, chlorine partial pressure, and reaction degree. PMID:22280490

  1. Chlorine dioxide and hemodialysis

    SciTech Connect

    Smith, R.P. . Dept. of Pharmacology and Toxicology)

    1989-05-01

    Because it has little or no tendency to generate carcinogenic trihalomethanes such as chloroform, chlorine dioxide is an attractive alternative to chlorine for drinking water disinfection. There are, however, concerns about its acute toxicity, and the toxic effects of its by-products, chlorite and chlorate. The human experience with chlorine dioxide in both controlled, prospective studies and in actual use situations in community water supplies have as yet failed to reveal adverse health effects. The EPA has recommended standards of 0.06 mg/L for chlorine dioxide and standards of 0.007 mg/L for chlorite and chlorate in drinking water. Among groups who may be at special risk from oxychlorines in drinking water are patients who must undergro chronic extracorporeal hemodialysis. Although even units for home hemodialysis are supposed to be equipped with devices which effectively remove oxychlorines, there is a always a possibility of operator error or equipment failure. When the equipment is adequately maintained, it is likely that dialysis patients will have more intensive exposures from drinking water than from dialysis fluids despite the much larger volumes of water that are involved in dialysis. This paper discusses a hemodialysis and the standards and effects of oxychlorines. 90 refs., 2 tabs.

  2. Chlorine Dioxide (Gas)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorine dioxide (ClO2) gas is registered by the U.S. Environmental Protection Agency (EPA) as a sterilant for use in manufacturing, laboratory equipment, medical devices, environmental surfaces, tools and clean rooms. Aqueous ClO2 is registered by the EPA as a surface disinfectant and sanitizer fo...

  3. Chlorine isotope variability in subglacial glasses from Iceland

    NASA Astrophysics Data System (ADS)

    Halldorsson, S. A.; Barnes, J.; Stefansson, A.; Hilton, D. R.; Hauri, E. H.

    2014-12-01

    Chlorine concentrations tend to be significantly enriched in surface reservoirs relative to that of the mantle. This large contrast in chlorine contents makes primary asthenospheric melts, highly susceptible to contamination by surficial chlorine in shallow-level crustal environments. Indeed, on the basis of both chlorine abundance systematics [e.g., 1], and chlorine isotopes [2], previous researchers have argued for a surficial chlorine component in controlling the chlorine systematics of MORB. In contrast, other studies suggest recycling of ancient chlorine via a subducted, altered oceanic lithospheric component as a means of controlling the chlorine isotope composition of the mantle [3]. So far, very few high precision chlorine isotope data are available from key oceanic islands, which potentially provide access to deeper parts of the mantle and thus allow for testing of the relative role of these ideas. We report new chlorine isotope (reported as δ37Cl; n=22) and abundance data (SIMS) derived from fresh subglacial glasses from Iceland. The glasses, which cover all the currently active volcanic zones of Iceland, span a wide range in their major element composition with MgO contents between 2.1 and 10.0 wt% and chlorine contents, that vary by almost two orders of magnitude, of 17 to 1270 ppm. Chlorine contents show significant correlations (R2 > 0.9) with incompatible elements such as potassium, consistent with earlier observations from Iceland and the adjacent Reykjanes Ridge [4, 5]. δ37Cl values range from -0.6‰ to +1.4‰. Significantly, δ37Cl values strongly correlate with Cl and MgO contents, with low δ37Cl values in samples with low Cl and high MgO concentrations. The data are consistent with mixing between two different reservoirs: a upper mantle reservoir with low Cl concentration and a slightly negative δ37Cl value and a crustal reservoir with a high Cl concentration and enriched in 37Cl. To further investigate the origin of these chlorine isotope

  4. Formation and speciation characteristics of brominated trihalomethanes in seawater chlorination.

    PubMed

    Padhi, R K; Sowmya, M; Mohanty, A K; Bramha, S N; Satpathy, K K

    2012-11-01

    Formation character of brominated-trihalomethanes (Br-THMs) in chlorinated seawater and its dependence on applied chlorine dose, reaction time, and temperature were investigated in the laboratory. Seawater was collected from the east coast of India and a chlorine dose of 1, 3, 5, and 10 ppm was each applied at a temperature of 20, 30, and 40 degrees C to investigate the yield and kinetics of Br-THMs formation. Qualitative and quantitative estimation of THM formation at various intervals of time ranging from 5 min to 168 h was determined by a gas chromatograph equipped with an electron capture detector (GC-ECD). Chlorine dose, chlorine contact time, and reaction temperature positively affected the load of THMs. The ratio of chlorine dose to halogen incorporation decreased from 12% to 5% with increasing applied chlorine dose from 1 to 10 ppm. Significant levels of THMs were found to be formed within 0.5 h of reaction, followed by a very slow rate of formation. Elevated temperature favored both increased rate of formation and overall THM yield. The formation order of different trihalomethane species at all studied temperatures was observed to be bromodichloromethane (CHCl2Br) < dibromochloromethane (CHClBr2) < bromoform (CHBr3). Formation of chloroform was not observed, and bromoform was the dominant (96% to 98%) among the three THM species formed. PMID:23356015

  5. Degradation mechanisms of geosmin and 2-MIB during UV photolysis and UV/chlorine reactions.

    PubMed

    Kim, Tae-Kyoung; Moon, Bo-Ram; Kim, Taeyeon; Kim, Moon-Kyung; Zoh, Kyung-Duk

    2016-11-01

    We conducted chlorination, UV photolysis, and UV/chlorin reactions to investigate the intermediate formation and degradation mechanisms of geosmin and 2-methylisoborneol (2-MIB) in water. Chlorination hardly removed geosmin and 2-MIB, while the UV/chlorine reaction at 254 nm completely removed geosmin and 2-MIB within 40 min and 1 h, respectively, with lesser removals of both compounds during UV photolysis. The kinetics during both UV photolysis and UV/chlorine reactions followed a pseudo first-order reaction. Chloroform was found as a chlorinated intermediate during the UV/chlorine reaction of both geosmin and 2-MIB. The pH affected both the degradation and chloroform production during the UV/chlorine reaction. The open ring and dehydration intermediates identified during UV/chlorine reactions were 1,4-dimethyl-adamantane, and 1,3-dimethyl-adamantane from geosmin, 2-methylenebornane, and 2-methyl-2-bornene from 2-MIB, respectively. Additionally, 2-methyl-3-pentanol, 2,4-dimethyl-1-heptene, 4-methyl-2-heptanone, and 1,1-dichloro-2,4-dimethyl-1-heptane were newly identified intermediates from UV/chlorine reactions of both geosmin and 2-MIB. These intermediates were degraded as the reaction progressed. We proposed possible degradation pathways during the UV photolysis and UV/chlorine reactions of both compounds using the identified intermediates. PMID:27494316

  6. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYPTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. xcystation and mouse infectivity were comparatively evaluated to assess oocyst viability. zone and chlorine dioxide more effectively inactivated oocysts than chlorine an...

  7. A comparison of chlorinated organic material produced by chlorine and chlorine dioxide bleaching

    SciTech Connect

    McKaque, A.B.; Reeve, D.W.

    1995-12-31

    Chlorine and chlorine dioxide react differently with pulp during bleaching and produce different types of organic by-products. The main differences are the large reduction in the amount of AOX (adsorbable organic halogen) in the effluent and EOX (extractable organic halogen) in the pulp. This talk reviews the differences in the amounts and types of chlorinated organic by-products produced by the two different bleaching agents.

  8. REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE

    EPA Science Inventory

    The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

  9. Tropospheric budget of reactive chlorine

    NASA Astrophysics Data System (ADS)

    Graedel, T. E.; Keene, W. C.

    1995-03-01

    Reactive chlorine in the lower atmosphere (as distinguished from chlorofluorocarbon-derived chlorine in the stratosphere) is important to considerations of precipitation acidity, corrosion, foliar damage, and chemistry of the marine boundary layer. Many of the chlorine-containing gases are difficult to measure, and natural sources appear to dominate anthropogenic sources for some chemical species. As a consequence, no satisfactory budget for reactive chlorine in the lower atmosphere is available. We have reviewed information on sources; source strengths; measurements in gas, aqueous, and aerosol phases; and chemical processes and from those data derive global budgets for nine reactive chlorine species and for reactive chlorine as a whole. The typical background abundance of reactive chlorine in the lower tropospheric is about 1.5 ppbv. The nine species, CH3 Cl, CH3 CCl3, HCl, CHClF2, Cl2* (thought to be HOCl and/or Cl2), CCl2 = CCl2, CH2 Cl2 , COCl2 , and CHCl3, each contribute at least a few percent to that total. The tropospheric reactive chlorine burden of approximately 8.3 Tg Cl is dominated by CH3 Cl (≈45 %) and CH3 CCl3 (≈25 %) and appears to be increasing by several percent per year. By far the most vigorous chlorine cycling appears to occur among seasalt aerosol, HCl, and Cl2*. The principal sources of reactive chlorine are volatilization from seasalt (enhanced by anthropogenically generated reactants), marine algae, volcanoes, and coal combustion (natural sources being thus quite important to the budget). It is anticipated that the concentrations of tropospheric reactive chlorine will continue to increase in the next several decades, particularly near urban areas in the rapidly developing countries.

  10. Chlorine adsorption on Au(111): chlorine overlayer or surface chloride?

    PubMed

    Gao, Weiwei; Baker, Thomas A; Zhou, Ling; Pinnaduwage, Dilini S; Kaxiras, Efthimios; Friend, Cynthia M

    2008-03-19

    We report the first scanning tunneling microscope (STM) investigation, combined with density functional theory calculations, to resolve controversy regarding the bonding and structure of chlorine adsorbed on Au(111). STM experiments are carried out at 120 K to overcome instability caused by mobile species upon chlorine adsorption at room temperature. Chlorine adsorption initially lifts the herringbone reconstruction. At low coverages (<0.33 ML), chlorine binds to the top of Au(111)-(1 x 1) surface and leads to formation of an overlayer with (square root(3) x square root(3))R30 degree structure at 0.33 ML. At higher coverages, packing chlorine into an overlayer structure is no longer favored. Gold atoms incorporate into a complex superlattice of a Au-Cl surface compound. PMID:18290645

  11. Toxicity, pharmacokinetics, and photodynamic properties of chlorin e6

    NASA Astrophysics Data System (ADS)

    Kostenich, Gennady; Zhuravkin, Ivan N.; Gurinovich, G. P.; Zhavrid, Edvard A.

    1993-03-01

    Toxicity, pharmacokinetics, and the tumor damage effect of chlorin e6 after light irradiation were studied. The results show that chlorin e6 LD50 value in C57Bl mice was 189 +/- 10 mg/kg, in non-inbred white rats it was 99 +/- 14 mg/kg 14 days after the agent iv injection. The concentration of chlorin e6 in blood, liver, kidney, spleen, and tumors (sarcoma M-1 and sarcoma 45) of the rats was determined by the fluorescence method 3, 6, 12, 18, 24, 48, and 72 hours after the agent iv injection at the dose of 10 mg/kg. For this purpose chlorin e6 was extracted from tissues by detergent triton X-100. The depth of necrosis spreading in tumor tissue was evaluated after chlorin e6 injection at the doses of 1 - 10 mg/kg and subsequent irradiation by a krypton laser with light energy density of 90 J/cm2, using the method of vital staining with Evans blue. It was found that depending on the agent dose and time interval between chlorin e6 injection and photoradiation, the depth of tumor necrosis varied from 4.0 to 16.6 mm in sarcoma M-1 and from 5.0 to 15.0 in sarcoma 45.

  12. [Synergistic disinfection of Bacillus subtilis spores by UV irradiation and chlorine].

    PubMed

    Zhang, Yong-ji; Liu, Wen-jun; Zhang, Lin

    2006-02-01

    The inactivation effect of Bacillus subtilis spores was studied, both UV irradiation and chlorine disinfection individual and combined application process was examined with laboratory water samples. Results show that only 0.53 lg reduction was achieved by chlorine with CT value of 300 (mg x min)/L, UV irradiation is more effective than that of chlorination, at a UV dose of 40mJ/cm2 results in 3.3 lg reduction. Up to 6.2 lg reduction are achieved with a UV dose of 40mJ/cm2 following by chlorine with CT value of 300 (mg x min)/L. The calculation from the Berenbaum formula verified that the effect of the combined applications of UV irradiation and chlorine in inactivatiing Bacillus subtilis is a kind of synergistic effect. PMID:16686199

  13. Synergistic effect between UV and chlorine (UV/chlorine) on the degradation of carbamazepine: Influence factors and radical species.

    PubMed

    Wang, Wen-Long; Wu, Qian-Yuan; Huang, Nan; Wang, Ting; Hu, Hong-Ying

    2016-07-01

    For successful wastewater reclamation, advanced oxidation processes have attracted attention for elimination of emerging contaminants. In this study, the synergistic treatment with UV irradiation and chlorine (UV/chlorine) was used to degrade carbamazepine (CBZ). Neither UV irradiation alone nor chlorination alone could efficiently degraded CBZ. UV/chlorine oxidation showed a significant synergistic effect on CBZ degradation through generation of radical species (OH and Cl), and this process could be well depicted by pseudo first order kinetic. The degradation rate constants (kobs,CBZ) of CBZ increased linearly with increasing UV irradiance and chlorine dosage. The degradation of CBZ by UV/chlorine in acidic solutions was more efficient than that in basic solutions mainly due to the effect of pH on the dissociation of HOCl and OCl(-) and then on the quantum yields and radical species quenching of UV/chlorine. When pH was increased from 5.5 to 9.5, the rate constants of degradation of CBZ by OH decreased from 0.65 to 0.14 min(-1) and that by Cl decreased from 0.40 to 0.11 min(-1). The rate constant for the reaction between Cl and CBZ was 5.6 ± 1.6 × 10(10) M(-1) s(-1). Anions of HCO3(-) (1-50 mM) showed moderate inhibition of CBZ degradation by UV/chlorine, while Cl(-) did not. UV/chlorine could efficiently degrade CBZ in wastewater treatment plant effluent, although the degradation was inhibited by about 30% compared with that in ultrapure water with chlorine dosage of 0.14-0.56 mM. Nine main oxidation products of the CBZ degradation by UV/chlorine were identified using the HPLC-QToF MS/MS. Initial oxidation products arose from hydroxylation, carboxylation and hydrogen atom abstraction of CBZ by OH and Cl, and were then further oxidized to generate acylamino cleavage and decarboxylation products of acridine and acridione. PMID:27105033

  14. Chlorinated hydrocarbons in peat

    SciTech Connect

    Rapaport, R.A.

    1985-01-01

    Concentrations (ng/g), accumulation rates (ug/m/sup 2/=yr) and burdens were determined for DDT (1,1,1-trichlorophenyl2-2'bis(p-chlorophenyl)ethane), polychlorinated biphenyls. Toxaphene, hexachlorobenzene (HCB) and a,b,g-hexachlorocyclohexanes (HCHs) in peat cores taken across the mid-latitudes of North America. Because peat bogs are ombrotrophic, thereby receiving all contaminant inputs from the atmosphere and because peat cores were dated, atmospheric input functions were constructed for all of the compounds listed above excepting the HCHs. Compound inventories (burdens) in peat cores of PCBs, HCB, HCHs, Toxaphene, DDT, Pb and Zn were compared, indicating a strong influence from areas proximate to industrial sources and the atmospheric transport from source regions. Untransformed parent DDT (p,p' and o,p'-DDT) in surface peat and in precipitation provides evidence for the long range transport of DDT from neighboring countries where use has increased over the past 10-15 years. Present accumulation rates of DDT in peat are about 10-20% of maximum levels associated with peak use in the US around 1960. The DDT input function that was developed can be used to date peat cores. Transformations of DDT and PCBs were also examined in peat cores. First order transformation rates of DDT (p,p' and o,p') to DDD in anaerobic peat core environments ranged from 0.03 to 0.09 yr/sup -1/ with differences related to temperature. Aerobic transformation of PCB congeners in peat cores and microcosms was rapid for 2,3 and several 4 chlorinated congeners (T/sub 1/2 less than or equal to 0.2 to 3 years) and declined with increasing chlorine number.

  15. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  16. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  17. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  18. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Chlorine. 151.50-31 Section 151.50-31 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-31 Chlorine. (a) Chlorine barges. Subparts 98.03 and 98.20 of Part 98 of this chapter have been revoked. However, chlorine barges that...

  19. Zebra mussel mortality with chlorine

    SciTech Connect

    Van Benschoten, J.E.; Jensen, J.N.; Harrington, D.; DeGirolamo, D.J.

    1995-05-01

    The rate of mortality of the zebra mussel in response to chlorine is described by a kinetic model that combines a statistical characterization of mussel mortality with a disinfection-type modeling approach. Parameter estimates were made with nine sets of data from experiments conducted in Niagara River water. From the kinetic model, an operational diagram was constructed that describes the time to 95% mortality as a function of chlorine concentration and temperature. Either the model or the diagram can be used to assist utilities in planning chlorination treatments for controlling zebra mussels.

  20. Leaching of oxidic zinc materials with chlorine and chlorine hydrate

    NASA Astrophysics Data System (ADS)

    Thomas, B. K.; Fray, D. J.

    1981-06-01

    Low grade zinc ores and residues were leached in chlorine water and chlorine hydrate water mixtures. It was found that the rate of leaching Adrar ore and Electric Arc Furnace dust obeyed a shrinking core diffusion model, whereas, the rate of leaching of Turkish ore appeared to be controlled by a surface reaction. In all cases, lead leached with the zinc but the iron oxides remained virtually undissolved.

  1. Gaseous, chlorine-free chlorine dioxide for drinking water

    SciTech Connect

    Gordon, G.; Rosenblatt, A.

    1996-11-01

    The benefits of applying chlorine dioxide (ClO{sub 2}) for the oxidative treatment of drinking water are well established. Chlorine dioxide treated finished water typically has substantially lower trihalomethane (THM) levels because ClO{sub 2} will not form chlorinated organic species as a by-product of disinfection. The THMs that are formed are probably due to chlorine from the generator or chlorine used to maintain a post-disinfection residual. An emerging regulatory issue concerning the formation of disinfection by-products (DBPs) is causing the water industry to set standards for the generation and delivery of ClO{sub 2}. The Federal Register (11 February 1994) contains language developed to limit the production of the unwanted inorganic by-products chlorite (ClO{sub 2}{sup -}), chlorate (ClO{sub 3}{sup -}), and bromate (BrO{sub 3}{sup -}) ions by requiring utilities to maintain high (95%) generation efficiencies and by limiting the amount of excess Cl{sub 2} that can be used during the generation process. The efficiency and excess Cl{sub 2} regulations may be problematic for utilities that over-chlorinate to attain chlorine dioxide high yields. Many utilities will have to decide either to reduce the amount of Cl{sub 2} used to react with sodium chlorite (NaClO{sub 2}), thereby increasing the ClO{sub 2}{sup -} residual in finished water, or over-chlorinate to increase yields and surpass the excess Cl{sub 2} limits.

  2. Effect of chlorination and ultraviolet disinfection on tetA-mediated tetracycline resistance of Escherichia coli.

    PubMed

    Huang, Jing-Jing; Hu, Hong-Ying; Wu, Yin-Hu; Wei, Bin; Lu, Yun

    2013-02-01

    Antibiotic-resistant bacteria are an emerging threat to public health during drinking water consumption and reclaimed water reuse. Several studies have shown that the proportions of antibiotic-resistant bacteria in waters may increase when exposed to low doses of UV light or chlorine. In this study, inactivation of tetracycline-resistant Escherichia coli and antibiotic-sensitive E. coli by UV disinfection and chlorination was compared to determine the tolerance of tetracycline-resistant E. coli to UV light and chlorine, and tetracycline resistance of a tetracycline-resistant E. coli population was studied under different doses of the disinfectants. Our results showed that relative to antibiotic-sensitive E. coli, tetracycline-resistant E. coli had the same tolerance to UV light and a potentially higher tolerance to chlorination. The mortality frequency distributions of tetracycline-resistant E. coli exposed to tetracycline were shifted by both chlorination and UV disinfection. When compared to the hemi-inhibitory concentrations (IC(50)) of tetracycline-resistant E. coli with no exposure to UV or chlorination, the IC(50) of tetracycline-resistant E. coli treated with tetracycline was 40% lower when inactivation by UV light or chlorination reached 3-log but was 1.18 times greater when inactivation by chlorination reached 4.3-log. Chlorination applied to drinking water or reclaimed water treatment may increase the risk of selection for highly tetracycline-resistant E. coli. PMID:23123077

  3. Process for Photochemical Chlorination of Hydrocarbons

    DOEpatents

    Beanblossom, W S

    1951-08-28

    A process for chlorination of a major portion of the hydrogen atoms of paraffinic hydrocarbons of five or more carbon atoms may be replaced by subjecting the hydrocarbon to the action of chlorine under active light. The initial chlorination is begun at 25 to 30 deg C with the chlorine diluted with HCl. The later stages may be carried out with undiluted chlorine and the temperature gradually raised to about 129 deg C.

  4. CHLORINATION OF AQUATIC HUMIC SUBSTANCES

    EPA Science Inventory

    This research program was initiated with the overall objective of increasing our understanding of the chemical structures of aquatic humic material and their behavior during chemical oxidation in particular with chlorine. Experimental methods were devised for the isolation of hum...

  5. CHLORINE INACTIVATION OF BACILLUS ENDOSPORES

    EPA Science Inventory

    The possibility of a bioterrorism event resulting in the release of Bacillus anthracis endospores into a drinking water distribution system necessitates research into means by which these endospores can be inactivated. This study was designed to determine the chlorine resistance...

  6. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporiodium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were compareatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlor...

  7. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Ozone, chlorine dioxide, and chloramine are currently popular alternatives to ...

  8. Transformation of iopamidol during chlorination.

    PubMed

    Wendel, Friedrich M; Lütke Eversloh, Christian; Machek, Edward J; Duirk, Stephen E; Plewa, Michael J; Richardson, Susan D; Ternes, Thomas A

    2014-11-01

    The transformation of the iodinated X-ray contrast media (ICM) iopamidol, iopromide, iohexol, iomeprol, and diatrizoate was examined in purified water over the pH range from 6.5 to 8.5 in the presence of sodium hypochlorite, monochloramine, and chlorine dioxide. In the presence of aqueous chlorine, only iopamidol was transformed. All other ICM did not show significant reactivity, regardless of the oxidant used. Chlorination of iopamidol followed a second order reaction, with an observed rate constant of up to 0.87 M(-1) s(-1) (±0.021 M(-1) s(-1)) at pH 8.5. The hypochlorite anion was identified to be the reactive chlorine species. Iodine was released during the transformation of iopamidol, and was mainly oxidized to iodate. Only a small percentage (less than 2% after 24 h) was transformed to known organic iodinated disinfection byproducts (DBPs) of low molecular weight. Some of the iodine was still present in high-molecular weight DBPs. The chemical structures of these DBPs were elucidated via MSn fragmentation and NMR. Side chain cleavage was observed as well as the exchange of iodine by chlorine. An overall transformation pathway was proposed for the degradation of iopamidol. CHO cell chronic cytotoxicity tests indicate that chlorination of iopamidol generates a toxic mixture of high molecular weight DBPs (LC50 332 ng/μL). PMID:25325766

  9. Cleaning without chlorinated solvents

    NASA Technical Reports Server (NTRS)

    Thompson, L. M.; Simandl, R. F.

    1995-01-01

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92 percent. The program has been a twofold effort. Vapor degreasers used in batch cleaning operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting, and bonding. Cleaning ability was determined using techniques such as x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes, and swelling of epoxies.

  10. Cleaning without chlorinated solvents

    SciTech Connect

    Thompson, L.M.; Simandl, R.F.

    1994-12-31

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

  11. Inactivation of antibiotic resistance genes in municipal wastewater effluent by chlorination and sequential UV/chlorination disinfection.

    PubMed

    Zhang, Yingying; Zhuang, Yao; Geng, Jinju; Ren, Hongqiang; Zhang, Yan; Ding, Lili; Xu, Ke

    2015-04-15

    This study investigated disinfection methods including chlorination, ultraviolet (UV) irradiation and sequential UV/chlorination treatment on the inactivation of antibiotic resistance genes (ARGs). ARGs including sul1, tetX, tetG, intI1, and 16S rRNA genes in municipal wastewater treatment plant (MWTP) effluent were examined. The results indicated a positive correlation between the removal of ARGs and chlorine dosage (p=0.007-0.014, n=6),as well as contact time (p=0.0001, n=10). Greater free chlorine (FC) dosage leads to higher removal for all the genes and the maximum removal (1.30-1.49 logs) could be achieved at FC dosage of 30 mg L(-1). The transformation kinetic data for ARGs removal (log C0/C) followed the second-order reaction kinetic model with FC dosage (R(2)=0.6829-0.9999) and contact time (R(2)=0.7353-8634), respectively. Higher ammonia nitrogen (NH3-N) concentration was found to lead to lower removal of ARGs at the same chlorine dosage. When the applied Cl2:NH3-N ratio was over 7.6:1, a significant reduction of ARGs (1.20-1.49 logs) was achieved. By using single UV irradiation, the log removal values of tetX and 16Ss rRNA genes were 0.58 and 0.60, respectively, while other genes were 0.36-0.40 at a fluence of 249.5 mJ cm(-2), which was observed to be less effective than chlorination. With sequential UV/chlorination treatment, 0.006 to 0.31 log synergy values of target genes were observed under different operation parameters. PMID:25616228

  12. Anaerobic biotransformation of chlorinated alkenes

    SciTech Connect

    Zhuang, P.

    1994-01-01

    Chlorinated alkenes are widely found in contaminated subsurface soil and groundwater. The highly chlorinated alkene (i.e., PCE) is not subject to aerobic biotransformation. The aim of this research was to explore the potential of using anaerobic processes (i.e., denitrification, sulfate-reduction and methanogenesis) for chlorinated alkenes biotransformation. Contaminated soil samples were used throughout this study. Soil microcosms simulating field anoxic conditions with various nutrients amendment, liquid microcosms as well as enrichment liquid cultures were developed to delineate the dechlorination process. The effect of biomass, chlorinated alkenes concentration and site specific conditions (e.g., temperature and pH) on the dechlorination and the primary metabolic process was investigated. The role of sorption and nutritional needs (i.e., electron donor) were also studied. A preliminary study revealed that denitrification was the least affected by low temperatures as compared to sulfate-reduction and methanogenesis. Although dechlorination took place under sequential denitrifying and methanogenic conditions and under sulfate-reducing conditions, further studies concluded that fermentative and methanogenic bacteria were responsible for the observed dechlorination. In most cases, dechlorination of PCE or TCE resulted in the accumulation of cDCE. However, a VC-producing culture was developed from the PCE-contaminated soil. In general, the dechlorination process could be enhanced by increasing electron donor and biomass concentration. At relatively low concentrations, the dechlorination rate was also increased with increasing chlorinated alkene concentration. Dechlorination even proceeded at high chlorinated alkene concentrations when methane production was inhibited. However, as the concentration of the chlorinated alkenes increased, severe toxicity eventually halted the dechlorination process.

  13. Chemistry of combined residual chlorination

    SciTech Connect

    Leao, S.F.; Selleck, R.E.

    1982-01-01

    The decay of the combined chlorine residual was investigated in this work. Recent concerns about the formation of undesirable compounds such as chloroform with free residual chlorination have focused attention on the alternative use of combined residual chlorination. This work investigates the applicability of reactions proposed to describe the transformations and decay of the combined residual with time. Sodium hypochlorite was added to buffered solutions of ammonia with the chlorine residual being monitored over periods extending up to 10 days. The reaction was studied at four initial concentrations of hypochlorite of 100, 50, 25 and 10 mg/L as Cl/sub 2/ with molar application ratios of chlorine to ammonia, defined herein as M ratios, of 0.90, 0.50, 0.25 and 0.05 at each hypochlorite dose. Sixty-eight experiments were conducted at the pH of 6.6 and 7.2. The conclusions are: (1) in the absence of free chlorine, the concentration of NH/sub 3/ does not seem to affect the rate of disappearance of the residual other than through the formation of NHCl/sub 2/ by NH/sub 2/Cl hydrolysis; (2) the reaction between NHCl/sub 2/ and NH/sub 4//sup +/ to form NH/sub 2/Cl is either much slower than reported by Gray et. al. or the mechanism is different with a rate limiting step not involving NH/sub 3/ or NH/sub 4//sup +/; (3) a redox reaction in addition to the first-order decomposition of NHCl/sub 2/ appears necessary. Model simulation results indicated that a reaction of the type NH/sub 2/Cl + NHCl/sub 2/ ..-->.. P added to the first-order NHCl/sub 2/ decomposition can explain the results observed except at the higher chlorine doses.

  14. Variation in assimilable organic carbon formation during chlorination of Microcystis aeruginosa extracellular organic matter solutions.

    PubMed

    Sun, Xingbin; Yuan, Ting; Ni, Huishan; Li, Yanpeng; Hu, Yang

    2016-07-01

    This study investigated the chlorination of Microcystis aeruginosa extracellular organic matter (EOM) solutions under different conditions, to determine how the metabolites produced by these organisms affect water safety and the formation of assimilable organic carbon (AOC). The effects of chlorine dosages, coagulant dosage, reaction time and temperature on the formation of AOC were investigated during the disinfection of M.aeruginosa metabolite solutions. The concentration of AOC followed a decreasing and then increasing pattern with increasing temperature and reaction time. The concentration of AOC decreased and then increased with increasing chlorination dosage, followed by a slight decrease at the highest level of chlorination. However, the concentration of AOC decreased continuously with increasing coagulant dosage. The formation of AOC can be suppressed under appropriate conditions. In this study, chlorination at 4mg/L, combined with a coagulant dose of 40mg/L at 20°C over a reaction time of 12hr, produced the minimum AOC. PMID:27372113

  15. A membrane process to recover chlorine from chloralkali plant tail gas

    SciTech Connect

    Lokhandwala, K.A.; Segelke, S.; Nguyen, P.; Baker, R.W.; Su, T.T.; Pinnau, I.

    1999-10-01

    Chlorine is manufactured by the electrolysis of brine. The chlorine product is a gas, which is collected, dried, compressed, and cooled to produce a liquid. This paper describes the development and field demonstration of a membrane process to recover chlorine from the liquefaction tail gas of chloralkali plants. The tail gas consists of about 20% chlorine and 50--70% air, with the balance being hydrogen and carbon dioxide. A number of membrane materials can achieve a selectivity of 20 or more for chlorine from nitrogen, but degradation of the membrane materials in the presence of high concentrations of chlorine gas often occurs. However, modified silicone rubber membranes are stable to chlorine gas streams. Silicone rubber composite membranes were prepared and formed into modules of 1--2 m{sup 2} membrane area. The modules were tested in the laboratory and in a field test on a slip stream from a chlorine liquefaction unit. In the laboratory, chlorine/nitrogen membrane selectivities of more than 40 were obtained, but selectivities of 6--10 were measured in the field test. This decrease in selectivity was caused by low gas flow rates through the modules, which resulted in concentration polarization effects. However, the membrane maintained essentially constant fluxes and selectivities in field tests lasting more than 1 month. Calculated plant designs based on a selectivity of 8 are able to recover more than 95% of the chlorine in the tail gas. Typical project payback times based on the value of the recovered chlorine and avoided caustic scrubber chemical use are expected to be 1--2 years.

  16. Evaluation of chlorine dioxide gas treatment to inactivate Salmonella enterica on mungbean sprouts.

    PubMed

    Prodduk, Vara; Annous, Bassam A; Liu, Linshu; Yam, Kit L

    2014-11-01

    Although freshly sprouted beans and grains are considered to be a source of nutrients, they have been associated with foodborne outbreaks. Sprouts provide good matrices for microbial localization and growth due to optimal conditions of temperature and humidity while sprouting. Also, the lack of a kill step postsprouting is a major safety concern. The objective of this work was to evaluate the effectiveness of chlorine dioxide gas treatment to reduce Salmonella on artificially inoculated mungbean sprouts. The effectiveness of gaseous chlorine dioxide (0.5 mg/liter of air) with or without tumbling (mechanical mixing) was compared with an aqueous chlorine (200 ppm) wash treatment. Tumbling the inoculated sprouts during the chlorine dioxide gas application for 15, 30, and 60 min reduced Salmonella populations by 3.0, 4.0, and 5.5 log CFU/g, respectively, as compared with 3.0, 3.0, and 4.0 log CFU/g reductions obtained without tumbling, respectively. A 2.0 log CFU/g reduction in Salmonella was achieved with an aqueous chlorine wash. The difference in microbial reduction between chlorine dioxide gas versus aqueous chlorine wash points to the important role of surface topography, pore structure, bacterial attachment, and/or biofilm formation on sprouts. These data suggested that chlorine dioxide gas was capable of penetrating and inactivating cells that are attached to inaccessible sites and/or are within biofilms on the sprout surface as compared with an aqueous chlorine wash. Consequently, scanning electron microscopy imaging indicated that chlorine dioxide gas treatment was capable of penetrating and inactivating cells attached to inaccessible sites and within biofilms on the sprout surfaces. PMID:25364920

  17. Influence of drinking water treatments on chlorine dioxide consumption and chlorite/chlorate formation.

    PubMed

    Sorlini, Sabrina; Gialdini, Francesca; Biasibetti, Michela; Collivignarelli, Carlo

    2014-05-01

    Disinfection is the last treatment stage of a Drinking Water Treatment Plant (DWTP) and is carried out to maintain a residual concentration of disinfectant in the water distribution system. Chlorine dioxide (ClO2) is a widely used chemical employed for this purpose. The aim of this work was to evaluate the influence of several treatments on chlorine dioxide consumption and on chlorite and chlorate formation in the final oxidation/disinfection stage. A number of tests was performed at laboratory scale employing water samples collected from the DWTP of Cremona (Italy). The following processes were studied: oxidation with potassium permanganate, chlorine dioxide and sodium hypochlorite, coagulation/flocculation with ferric chloride and aluminum sulfate, filtration and adsorption onto activated carbon. The results showed that the chlorine dioxide demand is high if sodium hypochlorite or potassium permanganate are employed in pre-oxidation. On the other hand, chlorine dioxide leads to the highest production of chlorite and chlorate. The coagulation/flocculation process after pre-oxidation shows that chlorine dioxide demand decreases if potassium permanganate is employed as an oxidant, both with ferric chloride and aluminum sulfate. Therefore, the combination of these processes leads to a lower production of chlorite and chlorate. Aluminum sulfate is preferable in terms of the chlorine dioxide demand reduction and minimization of the chlorite and chlorate formation. Activated carbon is the most effective solution as it reduced the chlorine dioxide consumption by about 50% and the DBP formation by about 20-40%. PMID:24534637

  18. Detection of chlorinated aromatic compounds

    DOEpatents

    Ekechukwu, A.A.

    1996-02-06

    A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

  19. Inactivation of Helicobacter pylori by chlorination.

    PubMed Central

    Johnson, C H; Rice, E W; Reasoner, D J

    1997-01-01

    Three strains of Helicobacter pylori were studied to determine their resistance to chlorination. The organisms were readily inactivated by free chlorine and should therefore be controlled by disinfection practices normally employed in the treatment of drinking water. PMID:9406419

  20. THE ROLE OF CHLORINE IN DIOXIN FORMATION

    EPA Science Inventory

    There is poor correlation between total chlorine in waste streams and formation of polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/F) during waste combustion. This is because the active chlorine (Cl) species are strongly dependent upon combustion conditions. ...

  1. Reactions of aqueous chlorine and chlorine dioxide with model food compounds.

    PubMed Central

    Fukayama, M Y; Tan, H; Wheeler, W B; Wei, C I

    1986-01-01

    Chlorine and chlorine dioxide (ClO2), common disinfecting and bleaching chemicals used in the food industry, are potent oxidizing and chlorinating agents. Unfortunately, little is known about the nature of the reactions of chlorine with organic food constituents. This presentation reviews published information concerning the reactions of chlorine gas (Cl2[g]), aqueous chlorine, and ClO2 with model food compounds, the fate of chlorine during the chlorination of specific food products, and the potential toxicity of the reaction products. Fatty acids and their methyl esters react with chlorine with the degree of incorporation corresponding to their degree of unsaturation. Aqueous chlorine oxidizes and chlorinates lipids and amino acids much more readily than ClO2. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and ClO2 with several food products, including flour and shrimp, have also been characterized. In one model system, 99% of Cl2(g) either reacted with components of flour or was consumed by oxidation/chlorination reactions. The lipids extracted from the chlorinated flour contained significant amounts of chlorine. Exposure of shrimp to hypochlorous acid (HOCl) solution resulted in significant incorporation of chlorine into the edible portion. Although significant quantities of chlorine can be incorporated into specific model compounds and food products, the health risks associated with exposure to chlorinated organic products are unknown. Preliminary studies using the Ames Salmonella/microsome mutagenicity assay indicate that the reaction products from mixtures of aqueous chlorine and various lipids or tryptophan are nonmutagenic. Nevertheless, additional studies are warranted, so that the toxicological significance of these reaction products can be understood more fully. PMID:3545804

  2. Radiolytic dechlorination of chlorinated organics

    NASA Astrophysics Data System (ADS)

    Taghipour, Fariborz; Evans, Greg J.

    1997-02-01

    The radiolytic dechlorination of 12 low molecular weight chlorinated organic compounds present in pulp mill effluent was investigated. For most of these chloro-organic compounds more than 90% dechlorination was obtained for gamma doses up to 20 kGy. Parameters such as the number of chlorine atoms and aqueous solution concentration were found to affect the dechlorination rate. A reaction set was also created to model the behavior of irradiated 0.49-49 mol m -3 chloroform solutions, giving good agreement with experimental results.

  3. Colorectal cancers and chlorinated water

    PubMed Central

    El-Tawil, Ahmed Mahmoud

    2016-01-01

    Published reports have revealed increased risk of colorectal cancers in people exposed to chlorinated drinking water or chemical derivatives of chlorination. Oestrogen plays a dual positive functions for diminishing the possibilities of such risk by reducing the entrance, and increasing the excretion, of these chemicals. In addition, there are supplementary measures that could be employed in order to reduce this risk further, such as boiling the drinking water, revising the standard concentrations of calcium, magnesium and iron in the public drinking water and prescribing oestrogen in susceptible individuals. Hypo-methylation of genomic DNA could be used as a biological marker for screening for the potential development of colorectal cancers. PMID:27096035

  4. STABLE CHLORINE ISOTOPE ANALYSIS OF CHLORINATED ORGANIC CONTAMINANTS

    EPA Science Inventory

    The biogeochemical cycling of chlorinated organic contaminants in the environment is often difficult to understand because of the complex distributions of these compounds and variability of sources. To address these issues from an isotopic perspective, we have measured the, 37Cl...

  5. An Easy Way To Make Chlorine Water

    NASA Astrophysics Data System (ADS)

    Holmes, L. H., Jr.

    1997-11-01

    Chlorine water can be made easily by mixing hypochlorite and hydrochloric acid. The equilibrium lies toward Cl2 in the reaction HOCl + HCl -> Cl2 + H2O and this can be used to make chlorine water from sodium hypochlorite and hydrochloric acid if the presence of NaCl in the chlorine water does not interfere with its use.

  6. 49 CFR 179.102-2 - Chlorine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Chlorine. 179.102-2 Section 179.102-2... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must be fabricated from carbon...

  7. 49 CFR 179.102-2 - Chlorine.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Chlorine. 179.102-2 Section 179.102-2... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must...

  8. 49 CFR 179.102-2 - Chlorine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Chlorine. 179.102-2 Section 179.102-2... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must be fabricated from carbon...

  9. 49 CFR 179.102-2 - Chlorine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Chlorine. 179.102-2 Section 179.102-2... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must be fabricated from carbon...

  10. 49 CFR 179.102-2 - Chlorine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Chlorine. 179.102-2 Section 179.102-2... Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.102-2 Chlorine. (a) Each tank car used to transport chlorine must comply with all of the following: (1) Tanks must be fabricated from carbon...

  11. BOOSTER CHLORINATION FOR MANAGING DISINFECTANT RESIDUALS

    EPA Science Inventory

    Booster chlorination is an approach to residual maintenance in which chlorine is applied at strategic locations within the distribution system. Situations in which booster chlorination may be most effective for maintaining a residual are explained informally in the context of a ...

  12. CHLORINE DIOXIDE FOR DRINKING WATER RESEARCH DIVISION

    EPA Science Inventory

    In order to comply with the trihalomethane regulation, many drinking water utilities have had to alter their treatment methods. ne option available to these utilities is to use a disinfectant other than chlorine such as chlorine dioxide. ith chlorine dioxide disinfection, trihalo...

  13. Disinfectants: Chlorine and chlorine dioxide. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-05-01

    The bibliography contains citations concerning the antimicrobial properties of chlorine and chlorine dioxide. The use of chlorine for the inactivation of viruses, bacteria, and fungi in wastewater treatment plants is discussed, including the mode of action and factors influencing inactivation. The use of chlorine dioxide as an alternative to chlorine disinfection in swimming pools and water supplies, and possible adverse effects are also discussed. (Contains a minimum of 157 citations and includes a subject term index and title list.)

  14. Growth of long chains in mixed ethylene-chlorine crystals at helium temperatures

    SciTech Connect

    Titov, V.A.; Filippov, P.G.; Misochko, E.Ya.; Usmanov, R.D.; Benderskii, V.A.

    1987-04-01

    The crystal growth of ethylene chloride under conditions of the chlorination of ethylene and the photolytic absorption of chlorine under the influence of the radiation of a helium-cadmium laser at 40 degrees Kelvin is studied using ultraviolet and infrared spectroscopy. The structural and kinetic analysis reveals information on the crystal and molecular structure and on the forbidden vibrational transitions and hyperfine splitting behavior occurring in the compound.

  15. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  16. NATURAL ATTENUATION OF CHLORINATED SOLVENTS

    EPA Science Inventory

    The protocol will simply describe in detail, with references and illustrations, the approach currently used by staff of the SPRD to evaluate natural attenuation of chlorinated solvents in ground water. Staff of SPRD, and staff of the Air Force Center for environmental excellence...

  17. VOLTAMMETRIC MEMBRANE CHLORINE DIOXIDE ELECTRODE

    EPA Science Inventory

    A voltammetric membrane electrode system has been modified and applied to the in situ measurement of chlorine dioxide. The electrode system consisted of a gold cathode, a silver/silver chloride reference electrode, and a gold counter electrode. Different membrane materials were t...

  18. Environmental factors regulating soil organic matter chlorination

    NASA Astrophysics Data System (ADS)

    Svensson, Teresia; Montelius, Malin; Reyier, Henrik; Rietz, Karolina; Karlsson, Susanne; Lindberg, Cecilia; Andersson, Malin; Danielsson, Åsa; Bastviken, David

    2016-04-01

    Natural chlorination of organic matter is common in soils. Despite the widespread abundance of soil chlorinated soil organic matter (SOM), frequently exceeding soil chloride abundance in surface soils, and a common ability of microorganisms to produce chlorinated SOM, we lack fundamental knowledge about dominating processes and organisms responsible for the chlorination. To take one step towards resolving the terrestrial chlorine (Cl) puzzle, this study aims to analyse how environmental factors influence chlorination of SOM. Four factors were chosen for this study: soil moisture (W), nitrogen (N), chloride (Cl) and organic matter quality (C). These factors are all known to be important for soil processes. Laboratory incubations with 36Cl as a Cl tracer were performed in a two soil incubation experiments. It was found that addition of chloride and nitrogen seem to hamper the chlorination. For the C treatment, on the other hand, the results show that chlorination is enhanced by increased availability of labile organic matter (glucose and maltose). Even higher chlorination was observed when nitrogen and water were added in combination with labile organic matter. The effect that more labile organic matter strongly stimulated the chlorination rates was confirmed by the second separate experiment. These results indicate that chlorination was not primarily a way to cut refractory organic matter into digestible molecules, representing one previous hypothesis, but is related with microbial metabolism in other ways that will be further discussed in our presentation.

  19. Factors affecting trihalomethane formation and speciation during chlorination of reclaimed water.

    PubMed

    Ma, Defang; Gao, Baoyu; Wang, Yan; Yue, Qinyan; Li, Qian

    2015-01-01

    A hybrid process with membrane bioreactor (MBR) and powdered activated carbon (PAC), PAC/MBR, was used for real municipal wastewater treatment and reuse. The roles of chlorine dose, contact time, pH and bromide in trihalomethane (THM) formation and speciation during chlorination of the reclaimed water were investigated. Total trihalomethane (TTHM) yield exponentially increased to maximum with increasing chlorine dose (correlation coefficient R2=0.98). Prolonging substrate chlorine contact time significantly promoted TTHM formation. Less than 40% of THMs formed in the first 24 h, indicating that the PAC/MBR effluent organic matters were mostly composed of slow-reacting precursors. Increasing pH and bromide concentration facilitated THM formation. Higher chlorine dose and contact time enhanced chloro-THM formation. The bromo-THM formation was favored at near neutral condition. Despite the variation of chlorine dose, contact time and pH, the yield of THM species in order was usually CHCl3>CHBrCl2>CHBr2Cl>CHBr3. However, THM speciation shifted from chlorinated species to brominated species with increasing bromide concentration. PMID:26247761

  20. Fate of Antibiotic Resistant Bacteria and Genes during Wastewater Chlorination: Implication for Antibiotic Resistance Control

    PubMed Central

    Yuan, Qing-Bin; Guo, Mei-Ting; Yang, Jian

    2015-01-01

    This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L). The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L). By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L). However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination. PMID:25738838

  1. Ordered chlorinated monolayer silicene structures

    NASA Astrophysics Data System (ADS)

    Li, Wenbin; Sheng, Shaoxiang; Chen, Jian; Cheng, Peng; Chen, Lan; Wu, Kehui

    2016-04-01

    We report on a systematic experimental study on the chlorination of monatomic silicene layer on Ag(111) by scanning tunneling microscopy. Monolayer silicene on Ag(111) can form 4×4, (√13×√13)R ± 13.9°, and (2√3×2√3)R30° reconstructions due to their different buckling configurations. We found that at low dosage, Cl atoms attach to the upper buckled Si atoms without changing the buckling configuration of the silicene monolayer. However, at high coverage, the global buckling configuration will be significantly changed, resulting in new ordered structures. Interestingly, all monolayer silicene structures, regardless of their initial reconstructions, tend to form a local silicene 1×1 structure at the saturation coverage. The mechanism for chlorination of monolayer silicene is explained.

  2. Chlorine signal attenuation in concrete.

    PubMed

    Naqvi, A A; Maslehuddin, M; ur-Rehman, Khateeb; Al-Amoudi, O S B

    2015-11-01

    The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method. PMID:26218450

  3. Detection of chlorinated aromatic compounds

    DOEpatents

    Ekechukwu, Amy A.

    1996-01-01

    A method for making a composition for measuring the concentration of chloated aromatic compounds in aqueous fluids, and an optical probe for use with the method. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis.

  4. Coal desulfurization by aqueous chlorination

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K. (Inventor)

    1982-01-01

    A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 C to 500 C to form a non-caking, low-sulfur coal product.

  5. Microbial based chlorinated ethene destruction

    DOEpatents

    Bagwell, Christopher E.; Freedman, David L.; Brigmon, Robin L.; Bratt, William B.; Wood, Elizabeth A.

    2009-11-10

    A mixed culture of Dehalococcoides species is provided that has an ability to catalyze the complete dechlorination of polychlorinated ethenes such as PCE, TCE, cDCE, 1,1-DCE and vinyl chloride as well as halogenated ethanes such as 1,2-DCA and EDB. The mixed culture demonstrates the ability to achieve dechlorination even in the presence of high source concentrations of chlorinated ethenes.

  6. Reactions of aqueous chlorine and chlorine dioxide with model food compounds

    SciTech Connect

    Fukayama, M.Y.; Tan, H.; Wheeler, W.B.; Wei, C.

    1986-11-01

    This presentation reviews published information concerning the reactions of chlorine gas (CL/sub 2/(g)), aqueous chlorine, and ClO/sub 2/ with model food compounds, the fate of chlorine during the chlorination of specific food products, and the potential toxicity of the reaction products. Fatty acids and their methyl esters react with chlorine with the degree of incorporation corresponding to their degree of unsaturation. Aqueous chlorine oxidizes and chlorinates lipids and amino acids much more readily than ClO/sub 2/. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and ClO/sub 2/ with several food products, including flour and shrimp, have also been characterized. Although significant quantities of chlorine can be incorporated into specific model compounds and food products, the health risks associated with exposure to chlorinated organic products are unknown. Preliminary studies using the Ames Salmonella/microsome mutagenicity assay indicate that the reaction products from mixtures of aqueous chlorine and various lipids or tryptophan are nonmutagenic. Nevertheless, additional studies are warranted, so that the toxicological significance of these reaction products can be understood more fully.

  7. The effect of chlorine and combined chlorine/UV treatment on coliphages in drinking water disinfection.

    PubMed

    Zyara, Alyaa M; Torvinen, Eila; Veijalainen, Anna-Maria; Heinonen-Tanski, Helvi

    2016-08-01

    Chlorine disinfection is a globally used method to ensure the safety of drinking water. However, it has not always been successful against viruses and, therefore, it is important to find new methods to disinfect water. Seventeen different coliphages were isolated from the treated municipal wastewater. These coliphages and MS2 were treated with different dosages of chlorine in drinking water, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method. PMID:27441859

  8. UV/chlorine process for ammonia removal and disinfection by-product reduction: comparison with chlorination.

    PubMed

    Zhang, Xinran; Li, Weiguang; Blatchley, Ernest R; Wang, Xiaoju; Ren, Pengfei

    2015-01-01

    The combined application of UV irradiation at 254 nm and chlorination (UV/chlorine process) was investigated for ammonia removal in water treatment. The UV/chlorine process led to higher ammonia removal with less chlorine demand, as compared to breakpoint chlorination. Chlorination of NH₃ led to NH₂Cl formation in the first step. The photolysis of NH₂Cl and radical- mediated oxidation of ammonia appeared to represent the main pathways for ammonia removal. The trivalent nitrogen of ammonia was oxidized, presumably by reactions with aminyl radicals and chlorine radicals. Measured products included NO₃⁻and NO₂⁻; it is likely that N₂ and N₂O were also generated. In addition, UV irradiation appeared to have altered the reactivity of NOM toward free chlorine. The UV/chlorine process had lower chlorine demand, less C-DBPs (THMs and HAAs), but more HANs than chlorination. These results indicate that the UV/chlorine process could represent an alternative to conventional breakpoint chlorination for ammonia-containing water, with several advantages in terms of simplicity, short reaction time, and reduced chemical dosage. PMID:25466638

  9. Perchlorate production by photodecomposition of aqueous chlorine solutions.

    PubMed

    Rao, Balaji; Estrada, Nubia; McGee, Shelly; Mangold, Jerry; Gu, Baohua; Jackson, W Andrew

    2012-11-01

    Aqueous chlorine solutions (defined as chlorine solutions (Cl(2,T)) containing solely or a combination of molecular chlorine (Cl(2)), hypochlorous acid (HOCl), and hypochlorite (OCl(-))) are known to produce toxic inorganic disinfection byproduct (e.g., chlorate and chlorite) through photoactivated transformations. Recent reports of perchlorate (ClO(4)(-)) production-a well-known thyroid hormone disruptor- from stored bleach solutions indicates the presence of unexplored transformation pathway(s). The evaluation of this potential ClO(4)(-) source is important given the widespread use of aqueous chlorine as a disinfectant. In this study, we perform detailed rate analysis of ClO(4)(-) generation from aqueous chlorine under varying environmental conditions including ultraviolet (UV) light sources, intensity, solution pH, and Cl(2,T) concentrations. Our results show that ClO(4)(-) is produced upon UV exposure of aqueous chlorine solutions with yields ranging from 0.09 × 10(-3) to 9.2 × 10(-3)% for all experimental conditions. The amount of ClO(4)(-) produced depends on the starting concentrations of Cl(2,T) and ClO(3)(-), UV source wavelength, and solution pH, but it is independent of light intensity. We hypothesize a mechanistic pathway derived from known reactions of Cl(2,T) photodecomposition that involves the reaction of Cl radicals with ClO(3)(-) to produce ClO(4)(-) with calculated rate coefficient (k(ClO4-)) of (4-40) × 10(5) M(-1) s(-1) and (3-250) × 10(5) M(-1) s(-1) for UV-B/C and UV-A, respectively. The measured ClO(4)(-) concentrations for both UV-B and UV-C experiments agreed well with our model (R(2) = 0.88-0.99), except under UV-A light exposure (R(2) = 0.52-0.93), suggesting the possible involvement of additional pathways at higher wavelengths. Based on our results, phototransformation of aqueous chlorine solutions at concentrations relevant to drinking water treatment would result in ClO(4)(-) concentrations (~0.1 μg L(-1)) much below the proposed

  10. Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas.

    PubMed

    Kim, Hyobi; Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak; Myeong, Donghoon; Chang, Byungjoon; Choe, Nong-Hoon

    2016-01-01

    Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry. PMID:27499670

  11. Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas

    PubMed Central

    Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak

    2016-01-01

    Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry. PMID:27499670

  12. Observations of interstellar chlorine and phosphorus

    NASA Technical Reports Server (NTRS)

    Jura, M.; York, D. G.

    1978-01-01

    Copernicus observations of interstellar Cl I, Cl II, and P II UV lines toward 10 stars are reported. Column densities are estimated for each species, and upper limits are computed for HCl column densities. Derivation of the gas-phase abundances of chlorine and phosphorus indicates that the averages of both the chlorine and the phosphorus logarithmic abundances relative to hydrogen are between 5.0 and 5.1. It is suggested that interstellar chlorine may be depleted by about a factor of 3 relative to the solar abundance and that interstellar phosphorus is depleted by a factor of 2 to 3. The results are shown to support the prediction that chlorine is ionized in regions containing primarily atomic oxygen and is neutral in regions where there is a significant amount of molecular hydrogen. The photoionization rate of neutral chlorine toward 15 Mon is estimated, and it is concluded that most chlorine is contained within the gas phase.

  13. PRODUCTION OF CHLORINE ATOMS FROM THE REACTION OF OH WITH CHLORINATED HYDROCARBONS

    EPA Science Inventory

    Measurements from previous studies have shown that when hydroxyl radicals react with various chlorinated hydrocarbons under atmospheric conditions, free chlorine atoms can be produced. hetechnique described in this study involves scavenging Cl atoms produced by the reaction (usin...

  14. IDENTIFICATION OF DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

    EPA Science Inventory

    Many drinking water treatment plants are currently using alternative disinfectants to treat drinking water, with ozone, chlorine dioxide, and chloramine being the most popular. However, compared to chlorine, which has been much more widely studied, there is little information abo...

  15. EVALUATION OF MUTAGENIC AND CARCINOGENIC PROPERTIES OF BROMINATED AND CHLORINATED ACETONITRILES: BY-PRODUCTS OF CHLORINATION

    EPA Science Inventory

    The present study was undertaken to determine if chlorinated and brominated acetonitriles formed during the chlorination of drinking water possess mutagenic and/or carcinogenic properties. Chloroacetonitrile (CAN), dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN), bromoc...

  16. Characterization and identification of a chlorine-resistant bacterium, Sphingomonas TS001, from a model drinking water distribution system.

    PubMed

    Sun, Wenjun; Liu, Wenjun; Cui, Lifeng; Zhang, Minglu; Wang, Bei

    2013-08-01

    This study describes the identification and characterization of a new chlorine resistant bacterium, Sphingomonas TS001, isolated from a model drinking water distribution system. The isolate was identified by 16s rRNA gene analysis and morphological and physiological characteristics. Phylogenetic analysis indicates that TS001 belongs to the genus Sphingomonas. The model distribution system HPC results showed that, when the chlorine residual was greater than 0.7 mg L(-1), 100% of detected heterotrophic bacteria (HPC) was TS001. The bench-scale inactivation efficiency testing showed that this strain was very resistant to chlorine, and 4 mg L(-1) of chlorine with 240 min retention time provided only approximately 5% viability reduction of TS001. In contrast, a 3-log inactivation (99.9%) was obtained for UV fluencies of 40 mJ cm(-2). A high chlorine-resistant and UV sensitive bacterium, Sphingomonas TS001, was documented for the first time. PMID:23648446

  17. 40 CFR 423.11 - Specialized definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... addition to the definitions set forth in 40 CFR part 401, the following definitions apply to this part: (a) The term total residual chlorine (or total residual oxidants for intake water with bromides) means the value obtained using the amperometric method for total residual chlorine described in 40 CFR part...

  18. Formation of chlorinated lipids post-chlorine gas exposure.

    PubMed

    Ford, David A; Honavar, Jaideep; Albert, Carolyn J; Duerr, Mark A; Oh, Joo Yeun; Doran, Stephen; Matalon, Sadis; Patel, Rakesh P

    2016-08-01

    Exposure to chlorine (Cl2) gas can occur during accidents and intentional release scenarios. However, biomarkers that specifically indicate Cl2 exposure and Cl2-derived products that mediate postexposure toxicity remain unclear. We hypothesized that chlorinated lipids (Cl-lipids) formed by direct reactions between Cl2 gas and plasmalogens serve as both biomarkers and mediators of post-Cl2 gas exposure toxicities. The 2-chloropalmitaldehyde (2-Cl-Pald), 2-chlorostearaldehyde (2-Cl-Sald), and their oxidized products, free- and esterified 2-chloropalmitic acid (2-Cl-PA) and 2-chlorostearic acid were detected in the lungs and plasma of mouse and rat models of Cl2 gas exposure. Levels of Cl-lipids were highest immediately post-Cl2 gas exposure, and then declined over 72 h with levels remaining 20- to 30-fold higher at 24 h compared with baseline. Glutathione adducts of 2-Cl-Pald and 2-Cl-Sald also increased with levels peaking at 4 h in plasma. Notably, 3-chlorotyrosine also increased after Cl2 gas exposure, but returned to baseline within 24 h. Intranasal administration of 2-Cl-PA or 2-Cl-Pald at doses similar to those formed in the lung after Cl2 gas exposure led to increased distal lung permeability and inflammation and systemic endothelial dysfunction characterized by loss of eNOS-dependent vasodilation. These data suggest that Cl-lipids could serve as biomarkers and mediators for Cl2 gas exposure and toxicity. PMID:27324796

  19. Chlorine hazard evaluation for the zinc-chlorine electric vehicle battery. Final technical report

    SciTech Connect

    Zalosh, R.G.; Bajpai, S.N.; Short, T.P.; Tsui, R.K.

    1980-04-01

    An evaluation of the hazards associated with conceivable accidental chlorine releases from zinc-chlorine electric vehicle batteries is presented. Since commercial batteries are not yet available, this hazard assessment is based both on theoretical chlorine dispersion models and small-scale and large-scale spill tests with chlorine hydrate. Six spill tests involving chlorine hydrate indicate that the danger zone in which chlorine vapor concentrations intermittently exceed 100 ppM extends at least 23 m directly downwind of a spill onto a warm road surface. Chlorine concentration data from the hydrate spill tests compare favorably with calculations based on a quasi-steady area source dispersion model and empirical estimates of the hydrate decomposition rate. The theoretical dispersion model has been combined with assumed hydrate spill probabilities and current motor vehicle accident statistics in order to project expected chlorine-induced fatality rates. These calculations indicate that expected chlorine fatality rates are several times higher in a city with a warm and calm climate than in a colder and windier city. Calculated chlorine-induced fatality rate projections for various climates are presented as a function of hydrate spill probability in order to illustrate the degree of vehicle/battery crashworthiness required to maintain chlorine-induced fatality rates below current vehicle fatility rates due to fires and asphyxiations.

  20. FATE OF CHROMIUM (III) IN CHLORINATED WATER

    EPA Science Inventory

    The oxidation of trivalent chromium, Cr(III), to the more toxic Cr(VI) in chlorinated water is thermodynamically feasible and was the subject of the study. The study found that free available chlorine (FAC) readily converts Cr(III) to Cr(VI) at a rate that is highly dependent upo...

  1. REACTION PRODUCTS FROM THE CHLORINATION OF SEAWATER

    EPA Science Inventory

    Chemical treatment of natural waters, in particular the use of chlorine as a biocide, modifies the chemistry of these waters in ways that are not fully understood. The research described in this report examined both inorganic and organic reaction products from the chlorination of...

  2. Chlorination products: emerging links with allergic diseases.

    PubMed

    Bernard, A

    2007-01-01

    Exposure of the human population to chlorination products has considerably increased during the 20(th) century especially after the 1960s with the development of public and leisure pools. The present article summarizes current knowledge regarding the human exposure to chlorination products and reviews studies suggesting that these chemicals might be involved in the development or exacerbation of allergic diseases. Populations regularly in contact with chlorination products such as swimmers, lifeguards or workers using chlorine as cleaning or bleaching agent show increased risks of allergic diseases or of respiratory disorders frequently associated with allergy. Experimental evidence suggests that chlorination products promote allergic sensitization by compromising the permeability or the immunoregulatory function of epithelial barriers. These findings led to the chlorine hypothesis proposing that the rise of allergic diseases could result less from the declining exposure to microbial agents (the hygiene hypothesis) than from the increasing and largely uncontrolled exposure to products of chlorination, the most widely used method to achieve hygiene in the developed world. Giving the increasing popularity of water recreational areas, there is an obvious need to assess the effects of chlorine-based oxidants on human health and their possible implication in the epidemic of allergic diseases. PMID:17627515

  3. Chemotaxis of Pseudomonas putida toward chlorinated benzoates

    SciTech Connect

    Harwood, C.S.; Parales, R.E.; Dispensa, M. )

    1990-05-01

    The chlorinated aromatic acids 3-chlorobenzoate and 4-chlorobenzoate are chemoattractants for Pseudomonas putida PRS2000. These compounds are detected by a chromosomally encoded chemotactic response to benzoate which is inducible by {beta}-ketoadipate, and intermediate of benzoate catabolism. Plasmid pAC27, encoding enzymes for 3-chlorobenzoate degradation, does not appear to carry genes for chemotaxis toward chlorinated compounds.

  4. Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability

    SciTech Connect

    Korich, D.G.; Mead, J.R.; Madore, M.S.; Sinclair, N.A.; Sterling, C.R. )

    1990-05-01

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water.

  5. Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.

    PubMed Central

    Korich, D G; Mead, J R; Madore, M S; Sinclair, N A; Sterling, C R

    1990-01-01

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water. PMID:2339894

  6. Chlorine

    MedlinePlus

    ... gas are inhaled. Fluid in the lungs (pulmonary edema) that may be delayed for a few hours ... problems such as fluid in the lungs (pulmonary edema) following the initial exposure. How people can protect ...

  7. Soil peroxidase-mediated chlorination of fulvic acid

    NASA Astrophysics Data System (ADS)

    Asplund, Gunilla; Borén, Hans; Carlsson, Uno; Grimvall, Anders

    Humic matter has recently been shown to contain considerable quantities of naturally produced organohalogens. The present study investigated the possibility of a non-specific, enzymatically mediated halogenation of organic matter in soil. The results showed that, in the presence of chloride and hydrogen peroxide, the enzyme chloroperoxidase (CPO) from the fungus Caldariomyces fumago catalyzes chlorination of fulvic acid. At pH 2.5 - 6.0, the chlorine to fulvic acid ratio in the tested sample was elevated from 12 mg/g to approximately 40-50 mg/g. It was also shown that this reaction can take place at chloride and hydrogen peroxide concentrations found in the environment. An extract from spruce forest soil was shown to have a measurable chlorinating capacity. The activity of an extract of 0.5 kg soil corresponded to approximately 0.3 enzyme units, measured as CPO activity. Enzymatically mediated halogenation of humic substances may be one of the mechanisms explaining the widespread occurrence of adsorbable organic halogens (AOX) in soil and water.

  8. Detection of chlorinated methanes by tin oxide gas sensors.

    PubMed

    Park, S H; Son, Y C; Shaw, B R; Creasy, K E; Suib, S L

    2001-08-01

    Tin oxide thin films prepared by thermal oxidation of Sn films were used for the detection of chlorinated methanes (CH2Cl2, CHCl3 and CCl4). This resulted in better chemical selectivity, sensitivity, response speed and detection limit than seen with previous detectors. The temperature dependence of the sensing of 1% CCl4 gas was studied and the best sensing behavior was observed at 300 degrees C. The films showed different chemical selectivity in both speed and direction of sensing response to each gas and were stable for more than 3 weeks under operating conditions. The films showed rapid gas sensing (<40 s to reach 90% of full response) and low detection limits (< 4 ppm CCl4). The role of oxygen in the detection of chlorinated methanes and in resistance changes without chlorinated methanes was also studied. The changes at the surface of the film after gas sensing were examined using scanning electron microscopy with energy-dispersive X-ray spectrometry. PMID:11534610

  9. Decontamination of Pangasius fish (Pangasius hypophthalmus) with chlorine or peracetic acid in the laboratory and in a Vietnamese processing company.

    PubMed

    Tong Thi, Anh Ngoc; Sampers, Imca; Van Haute, Sam; Samapundo, Simbarashe; Ly Nguyen, Binh; Heyndrickx, Marc; Devlieghere, Frank

    2015-09-01

    This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400mg O2/L of COD after only 24min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150ppm at contact times of 10, 20 and 240s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0-1.0 and 0.4-1.4logCFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53-83% of chlorine and 15-17% of PAA were lost after washing for 40s (COD=238.2±66.3mg O2/L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy. PMID:26058007

  10. Chlorine-induced cardiopulmonary injury.

    PubMed

    Carlisle, Matthew; Lam, Adam; Svendsen, Erik R; Aggarwal, Saurabh; Matalon, Sadis

    2016-06-01

    Chlorine (Cl2 ) is utilized worldwide for a diverse range of industrial applications, including pulp bleaching, sanitation, and pharmaceutical development. Though Cl2 has widespread use, little is known regarding the mechanisms of toxicity associated with Cl2 exposure, which occurs during industrial accidents or acts of terrorism. Previous instances of Cl2 exposure have led to reported episodes of respiratory distress that result in high morbidity and mortality. Furthermore, studies suggest that acute Cl2 exposure also results in systemic vascular injury and subsequent myocardial contractile dysfunction. Here, we review both lung and cardiac pathology associated with acute Cl2 inhalation and discuss recently published data that suggest that mitochondrial dysfunction underlies the pathogenesis of Cl2 -induced toxicity. Last, we discuss our findings that suggest that upregulation of autophagy protects against Cl2 -induced lung inflammation and can be a potential therapeutic target for ameliorating the toxic effects of Cl2 exposure. PMID:27303906

  11. The occurrence of chlorine in serpentine minerals

    USGS Publications Warehouse

    Miura, Y.; Rucklidge, J.; Nord, G.L., Jr.

    1981-01-01

    Partially serpentinized dunites containing small amounts of Chlorine (< 0.5%) from Dumont, Quebec, and Horoman, Hokkaido, Japan, and one containing less than 0.05% Chlorine from Higashi-Akaishi-Yama, Ehime, Japan have been examined using the electron probe microanalyzer and scanning transmission electron microscope with X-ray analytical capabilities. Chlorine was found together with Si, Mg, Ca and Fe in the serpentine minerals of the Dumont and Hokkaido dunites but not in the Ehime dunite. Chlorine is found associated only with the most finely crystalline facies of the serpentine (grain size less than 10 nm). The Ehime dunite contained no such fine grained serpentine, and was thus effectively chlorine-free, as are the coarser grained serpentines of the other samples. The finegrained chlorine-bearing serpentine also has a much higher concentration of Fe, and can contain smaller amounts of Ca, Ni and Mn than the coarse-grained variety as well as minute awaruite (FeNi3) grains. This fine-grained serpentine probably represents an early stage in the transformation of olivine to serpentine, with chlorine from hydrothermal solutions assisting the necessary chemical changes. The Cl increases the reaction rate by lowering the activation barrier to reaction by the introduction of reaction steps. ?? 1981 Springer-Verlag.

  12. Legionella pneumophila transcriptional response to chlorine treatment.

    PubMed

    Bodet, Charles; Sahr, Tobias; Dupuy, Mathieu; Buchrieser, Carmen; Héchard, Yann

    2012-03-01

    Legionella pneumophila is a ubiquitous environmental microorganism found in freshwater that can cause an acute form of pneumonia known as Legionnaires' disease. Despite widespread use of chlorine to ensure drinking water quality and awareness that L. pneumophila may escape these treatments, little is known about its effects on L. pneumophila. The aim of this study was to investigate the L. pneumophila transcriptional response induced by chlorine treatment. Transcriptome analysis, using DNA arrays, showed that a sublethal dose of chlorine induces a differential expression of 391 genes involved in stress response, virulence, general metabolism, information pathways and transport. Many of the stress response genes were significantly upregulated, whereas a significant number of virulence genes were repressed. In particular, exposure of L. pneumophila to chlorine induced the expression of cellular antioxidant proteins, stress proteins and transcriptional regulators. In addition, glutathione S-transferase specific activity was enhanced following chlorine treatment. Our results clearly indicate that chlorine induces expression of proteins involved in cellular defence mechanisms against oxidative stress that might be involved in adaptation or resistance to chlorine treatment. PMID:22192759

  13. Acanthamoeba castellanii: cellular changes induced by chlorination.

    PubMed

    Mogoa, Emerancienne; Bodet, Charles; Legube, Bernard; Héchard, Yann

    2010-09-01

    Chlorination is a well-known disinfection method, used in water treatment to inactivate various microorganisms, it induces numerous cellular changes. Even though Acanthamoebae are frequently found in water, the cellular changes induced in Acanthamoebae have not been described in the literature. Acanthamoebae are pathogenic amoebae and may provide a reservoir for pathogenic bacteria such as Legionellapneumophila; it is consequently important to understand the response of this amoeba to chlorination, and our study was indeed aimed at examining cellular changes in Acanthamoebae following chlorination. Acanthamoeba trophozoites were treated at various chlorine concentrations (1-5mg/L). A 3-log reduction in Acanthamoebae population was achieved with 5mg/L of free chlorine. Confocal microscopy and flow cytometry experiments indicated that chlorination induced cell permeabilization, size reduction and likely intracellular thiol concentration. Our data show that among the non-cultivable cells some remained impermeabilized (negative staining with propidium iodide), thereby suggesting that these cells might remained viable. A similar state is described in other microorganisms as a VBNC (viable but not cultivable) state. Electron microscopy observations illustrate drastic morphological changes: the pseudopods disappeared and subcellular components, such as mitochondrion, were pronouncedly affected. In conclusion, depending on the concentration used, chlorination leads to many cellular effects on Acanthamoeba that could well arise in cell inactivation. PMID:20034490

  14. Toxicity of chlorine to zebrafish embryos

    PubMed Central

    Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

    2014-01-01

    Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

  15. Chlorination. Training Module 2.300.2.77.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with chlorine, the reasons for chlorination and safe operation and maintenance of gas chlorine, dry calcium hypochlorite and liquid sodium hypochlorite chlorination systems for water supply and wastewater treatment facilities. Included are…

  16. Chlorination of Wastewater, Manual of Practice No. 4.

    ERIC Educational Resources Information Center

    Water Pollution Control Federation, Washington, DC.

    This manual reviews chlorination practices in the treatment and disposal of wastes from the earliest known applications. The application of chlorination for various purposes is described but no attempt has been made to compare chlorination with other methods. Included are chapters on the development and practice of wastewater chlorination,…

  17. Influence of Chlorine Emissions on Ozone Levels in the Troposphere

    EPA Science Inventory

    Chlorine emissions from cooling towers are emitted mainly as hypochlous acid, not as molecular chlorine. Chlorine emissions from cooling towers in electric utilities in the U.S. are estimated to be 4,400 tons per year. Molecular chlorine increases more tropospheric ozone than hyp...

  18. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... chlorination of polyethylene conforming to the density, maximum n-hexane extractable fraction, and maximum... polyethylene is limited to use only as a modifier admixed at levels not exceeding 15 weight percent in...

  19. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... produced by the direct chlorination of polyethylene conforming to the density, maximum n-hexane extractable... percent in plastic articles prepared from polyvinyl chloride and/or from vinyl chloride...

  20. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Chlorine in Vinyl Chloride Polymers and Copolymers,” which is incorporated by reference (Copies may be... percent in plastic articles prepared from polyvinyl chloride and/or from vinyl chloride...

  1. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Chlorine in Vinyl Chloride Polymers and Copolymers,” which is incorporated by reference (Copies may be... percent in plastic articles prepared from polyvinyl chloride and/or from vinyl chloride...

  2. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Chlorine in Vinyl Chloride Polymers and Copolymers,” which is incorporated by reference (Copies may be... percent in plastic articles prepared from polyvinyl chloride and/or from vinyl chloride...

  3. Innovative Technologies for Chlorinated Solvent Remediation

    NASA Astrophysics Data System (ADS)

    Pennell, Kurt D.; Cápiro, Natalie L.

    2014-07-01

    The following sections are included: * INTRODUCTION * TRADITIONAL REMEDIATION TECHNOLOGIES (1980s) * RESEARCH AND DEVELOPMENT OF INNOVATIVE REMEDIATION TECHNOLOGIES (1990s-2000s) * CURRENT TRENDS IN CHLORINATED SOLVENT REMEDIATION (2010s) * CLOSING THOUGHTS * REFERENCES

  4. Behavior of chlorine during coal pyrolysis

    USGS Publications Warehouse

    Shao, D.; Hutchinson, E.J.; Cao, H.; Pan, W.-P.; Chou, C.-L.

    1994-01-01

    The behavior of chlorine in Illinois coals during pyrolysis was evaluated by combined thermo-gravimetry-Fourier transform infrared spectroscopy-ion chromatography (TG-FTIR-IC) techniques. It was found that more than 90% of chlorine in Illinois coals (IBC-103, 105, 106, and 109) was liberated as HCl gas during pyrolysis from 300 to 600??C, with the rate reaching a maximum at 440 ??C. Similarity of the HCl and NH3 release profiles during pyrolysis of IBC-109 supports the hypothesis that the chlorine in coal may be associated with nitrogen and the chlorine is probably bonded to the basic nitrogen sites on the inner walls of coal micropores. ?? 1994 American Chemical Society.

  5. Ozone depletion and chlorine loading potentials

    NASA Technical Reports Server (NTRS)

    Pyle, John A.; Wuebbles, Donald J.; Solomon, Susan; Zvenigorodsky, Sergei; Connell, Peter; Ko, Malcolm K. W.; Fisher, Donald A.; Stordal, Frode; Weisenstein, Debra

    1991-01-01

    The recognition of the roles of chlorine and bromine compounds in ozone depletion has led to the regulation or their source gases. Some source gases are expected to be more damaging to the ozone layer than others, so that scientific guidance regarding their relative impacts is needed for regulatory purposes. Parameters used for this purpose include the steady-state and time-dependent chlorine loading potential (CLP) and the ozone depletion potential (ODP). Chlorine loading potentials depend upon the estimated value and accuracy of atmospheric lifetimes and are subject to significant (approximately 20-50 percent) uncertainties for many gases. Ozone depletion potentials depend on the same factors, as well as the evaluation of the release of reactive chlorine and bromine from each source gas and corresponding ozone destruction within the stratosphere.

  6. Imidazole catalyzes chlorination by unreactive primary chloramines

    PubMed Central

    Roemeling, Margo D.; Williams, Jared; Beckman, Joseph S.; Hurst, James K.

    2015-01-01

    Hypochlorous acid and simple chloramines (RNHCl) are stable biologically-derived chlorinating agents. In general, the chlorination potential of HOCl is much greater than that of RNHCl, allowing it to oxidize or chlorinate a much wider variety of reaction partners. However, in this study we demonstrate by kinetic analysis that the reactivity of RNHCl can be dramatically promoted by imidazole and histidyl model compounds via intermediary formation of the corresponding imidazole chloramines. Two biologically relevant reactions were investigated—loss of imidazole-catalyzed chlorinating capacity and phenolic ring chlorination using fluorescein and the tyrosine analog, 4-hydroxyphenylacetic acid (HPA). HOCl reacted stoichiometrically with imidazole, N-acetylhistidine (NAH), or imidazoleacetic acid to generate the corresponding imidazole chloramines which subsequently decomposed. Chloramine (NH2Cl) also underwent a markedly accelerated loss in chlorinating capacity when NAH was present, although in this case NAHCl did not accumulate, indicating that the catalytic intermediate must be highly reactive. Mixing HOCl with 1-methylimidazole (MeIm) led to very rapid loss in chlorinating capacity via formation of a highly reactive chlorinium ion (MeImCl+) intermediate; this behavior suggests that the reactive forms of the analogous imidazole chloramines are their conjugate acids, e.g., the imidazolechlorinium ion (HImCl+). HOCl-generated imidazole chloramine (ImCl) reacted rapidly with fluorescein in a specific acid-catalyzed second order reaction to give 3′-monochloro and 3′,5′-dichloro products. Equilibrium constants for the transchlorination reactions: HOCl + HIm = H2O + ImCl and NH2Cl + HIm = NH3 + ImCl were estimated from the dependence of the rate constants upon [HIm]/[HOCl] and literature data. Acid catalysis again suggests that the actual chlorinating agent is HImCl+; consistent with this interpretation, MeIm markedly catalyzed fluorescein chlorination by HOCl

  7. Imidazole catalyzes chlorination by unreactive primary chloramines.

    PubMed

    Roemeling, Margo D; Williams, Jared; Beckman, Joseph S; Hurst, James K

    2015-05-01

    Hypochlorous acid and simple chloramines (RNHCl) are stable biologically derived chlorinating agents. In general, the chlorination potential of HOCl is much greater than that of RNHCl, allowing it to oxidize or chlorinate a much wider variety of reaction partners. However, in this study we demonstrate by kinetic analysis that the reactivity of RNHCl can be dramatically promoted by imidazole and histidyl model compounds via intermediary formation of the corresponding imidazole chloramines. Two biologically relevant reactions were investigated--loss of imidazole-catalyzed chlorinating capacity and phenolic ring chlorination using fluorescein and the tyrosine analog, 4-hydroxyphenylacetic acid (HPA). HOCl reacted stoichiometrically with imidazole, N-acetylhistidine (NAH), or imidazoleacetic acid to generate the corresponding imidazole chloramines which subsequently decomposed. Chloramine (NH2Cl) also underwent a markedly accelerated loss in chlorinating capacity when NAH was present, although in this case N-α-acetylhistidine chloramine (NAHCl) did not accumulate, indicating that the catalytic intermediate must be highly reactive. Mixing HOCl with 1-methylimidazole (MeIm) led to very rapid loss in chlorinating capacity via formation of a highly reactive chlorinium ion (MeImCl(+)) intermediate; this behavior suggests that the reactive forms of the analogous imidazole chloramines are their conjugate acids, e.g., the imidazolechlorinium ion (HImCl(+)). HOCl-generated imidazole chloramine (ImCl) reacted rapidly with fluorescein in a specific acid-catalyzed second-order reaction to give 3'-monochloro and 3',5'-dichloro products. Equilibrium constants for the transchlorination reactions HOCl + HIm = H2O + ImCl and NH2Cl + HIm = NH3 + ImCl were estimated from the dependence of the rate constants on [HIm]/[HOCl] and literature data. Acid catalysis again suggests that the actual chlorinating agent is HImCl(+); consistent with this interpretation, MeIm markedly catalyzed

  8. Stratospheric chlorine: Blaming it on nature

    SciTech Connect

    Taube, G.

    1993-06-11

    Much of the bitter public debate over ozone depletion has centered on the claim that chlorofluorocarbons (CFCs) pale into insignificance alongside natural sources of chlorine in the stratosphere. If so, goes the argument, chlorine could not be depleting ozone as atmospheric scientists claim, because the natural sources have been around since time immemorial, and the ozone layer is still there. The claim, put forward in a book by Rogelio Maduro and Ralf Schauerhammer, has since been touted by former Atomic Energy Commissioner Dixy Lee Ray and talk-show host Rush Limbaugh, and it forms the basis of much of the backlash now being felt by atmospheric scientists. The argument is simple: Maduro and Schauerhammer calculate that 600 million tons of chlorine enters the atmosphere annually from seawater, 36 million tons from volcanoes, 8.4 million tons from biomass burning, and 5 million tons from ocean biota. In contrast, CFCs account for a mere 750,000 tons of atmospheric chlorine a year. Besides disputing the numbers, scientists have both theoretical and observational bases for doubting that much of this chlorine is getting into the stratosphere, where it could affect the ozone layer. Linwood Callis of the National Aeronautics and Space Administration's (NASA) Langley Research Center points out one crucial problem with the argument: Chlorine from natural sources is soluble, and so it gets rained out of the lower atmosphere. CFCs, in contrast, are insoluble and inert and thus make it to the stratosphere to release their chlorine. What's more, observations of stratospheric chemistry don't support the idea that natural sources are contributing much to the chlorine there.

  9. Reaction mechanism for chlorination of urea.

    PubMed

    Blatchley, Ernest R; Cheng, Mingming

    2010-11-15

    Experiments were conducted to elucidate the mechanism of the reaction between free chlorine and urea. In combination with findings of previous investigations, the results of these experiments indicate a process by which urea undergoes multiple N-chlorination steps. The first of these steps results in the formation of N-chlorourea; this step appears to require Cl₂ to proceed and is the overall rate-limiting step in the reaction for conditions that correspond to most swimming pools. N-Chlorourea then appears to undergo further chlorine substitution; the fully N-chlorinated urea molecule is hypothesized to undergo hydrolysis and additional chlorination to yield NCl₃ as an intermediate. NCl₃ is hydrolyzed to yield NH₂Cl and NHCl₂, with subsequent decay to stable end products, including N₂ and NO₃⁻. Conversion of urea-N to nitrate is pH-dependent. The pattern of nitrate yield is believed to be attributable to the fact that when urea serves as the source of reduced-N, entry into the reactions that describe chlorination of ammoniacal nitrogen is through NCl₃, whereas when NH₃ is the source of reduced-N, entry to these reactions is through NH₂Cl. PMID:20964367

  10. Chemistry of saline-water chlorination

    SciTech Connect

    Haag, W.R.

    1981-06-01

    Vast quantities of natural waters are used by power plants for cooling purposes. This water is chlorinated to prevent slime build-up inside the cooling pipes, is circulated through the cooling system, and eventually discharged back into the water body. In order to assess the environmental impact of water chlorination, it is necessary to know what chemical compounds are produced and discharged into the receiving waters. To attack this problem, a review of the present state of knowledge of natural water chlorination chemistry was performed, and some experimental work explained the results of previous workers by showing that chlorine losses at very high doses in seawater are simply the result of chlorate and bromate formation which, however, is negligible at normal doses. The most important chlorine-produced oxidants, along with the relevant chemical reactions, were chosen as a basis for a kinetic model of saline water chlorination chemistry. Kinetic data were compiled in a computer program which simultaneously solves 24 differential equations, one for each species modelled. Estimates were made for the unknown rate constants. A purely predictive model was not possible due to the great variability in the organic demand; however, the model is applicable under a broad variety of conditions (except sunlight), and it provides a reasonably good description of a halamine chemistry under environmental conditions.

  11. Impact of Chlorine and Heat on the Survival of Hartmannella vermiformis and Subsequent Growth of Legionella pneumophila

    PubMed Central

    Kuchta, John M.; Navratil, Jeannine S.; Shepherd, Megan E.; Wadowsky, Robert M.; Dowling, John N.; States, Stanley J.; Yee, Robert B.

    1993-01-01

    Hartmannella vermiformis, a common amoebal inhabitant of potable-water systems, supports intracellular multiplication of Legionella pneumophila and is probably important in the transportation and amplification of legionellae within these systems. To provide a practical guide for decontamination of potable-water systems, we assessed the chlorine and heat resistance of H. vermiformis. H. vermiformis cysts and trophozoites were treated independently with chlorine at concentrations of 2.0 to 10.0 ppm for 30 min and then cocultured with L. pneumophila. Both cysts and trophozoites were sensitive to concentrations between 2.0 and 4.0 ppm and above (trophozoites somewhat more so than cysts), and 10.0 ppm was lethal to both forms. Hartmannellae treated with chlorine up to a concentration of 4.0 ppm supported the growth of legionellae. To determine whether heat would be an effective addendum to chlorine treatment of amoebae, hartmannellae were subjected to temperatures of 55 and 60°C for 30 min and alternatively to 50°C followed by treatment with chlorine at a concentration of 2 ppm. Fewer than 0.05% of the amoebae survived treatment at 55°C, and there were no survivors at 60°C. Pretreatment at 50°C appeared to make hartmannella cysts more susceptible to chlorine but did not further reduce the concentration of trophozoites. PMID:16349110

  12. 40 CFR Table 2 to Subpart Mmm of... - Standards for New and Existing PAI Sources

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Monitoring and leak repair program as in HON. a Table 9 is listed in the appendix to subpart G of 40 CFR part... ≤20 ppmv TOC. Processes having uncontrolled HCl and chlorine emissions ≥6.8 Mg/yr 94% for HCl and chlorine per process or to outlet HCl and chlorine concentration of ≤20 ppmv. Individual process...

  13. Maxillofacial prostheses of chlorinated polyethylene.

    PubMed

    May, P D

    1978-05-01

    There is clearly a need for maxillofacial prosthetic materials with improved properties. The chlorinated polyethylenes are thermoplastic elastomers which have particularly promising properties, and were used by us to prepare improved maxillofacial prostheses. Suitable CPE resins were compounded with other polymers and with pigments on a heated rubber mill to form thin sheets in a variety of shades. These were heated at 190 degrees C for 10 min and placed between heated linotype mold halves. The prosthesis was formed in a hand press. Sometimes heating and pressing were repeated. After cooling in water, the prosthesis was removed and hand-shaded with oil-soluble dyes. Physical properties were evaluated using standard techniques; skin irritation studies were conducted by 14-day insult patch tests on rabbits. Clinical evaluations were conducted on human volunteers. Parallel evaluations were conducted on commerically available materials for comparison. The CPE was superior to all of the three commerical materials in most properties, and comparable to the better of the three in the remaining properties. On balance, CPE was significantly superior. Early results indicate that the materials and techniques required are easily handled in the dental lab and that the final prosthesis has excellent aesthetic and patient acceptability. PMID:670262

  14. Chlorine isotope geochemistry of Icelandic thermal fluids: Implications for geothermal system behavior at divergent plate boundaries

    NASA Astrophysics Data System (ADS)

    Stefánsson, Andri; Barnes, Jaime D.

    2016-09-01

    The chlorine isotope composition of thermal fluids from Iceland were measured in order to evaluate the source of chlorine and possible chlorine isotope fractionation in geothermal systems at divergent plate boundaries. The geothermal systems studied have a wide range of reservoir temperatures from 40 to 437 °C and in-situ pH of 6.15 to 7.15. Chlorine concentrations range from 5.2 to 171 ppm and δ37 Cl values are -0.3 to + 2.1 ‰ (n = 38). The δ37 Cl values of the thermal fluids are interpreted to reflect the source of the chlorine in the fluids. Geothermal processes such as secondary mineral formation, aqueous and vapor speciation and boiling were found to have minimal effects on the δ37 Cl values. However, further work is needed on incorporation of Cl into secondary minerals and its effect on Cl isotope fractionation. Results of isotope geochemical modeling demonstrate that the range of δ37 Cl values documented in the natural thermal fluids can be explained by leaching of the basaltic rocks by meteoric source water under geothermal conditions. Magmatic gas partitioning may also contribute to the source of Cl in some cases. The range of δ37 Cl values of the fluids result mainly from the large range of δ37 Cl values observed for Icelandic basalts, which range from -0.6 to + 1.2 ‰.

  15. The effect of advanced treatment on chlorine decay in metallic pipes.

    PubMed

    Rossman, Lewis A

    2006-07-01

    Experiments were run to measure what effect advanced treatment might have on the kinetics of chlorine and chloramine decay in metallic pipes that comprise many drinking water distribution systems. A recirculating loop of 6-in diameter unlined ductile iron pipe was used to simulate turbulent flow conditions in a pipe with significant corrosion and tubercle buildup. Conventionally treated test water was subjected to either ozonation, carbon adsorption (GAC), reverse osmosis (RO) or no further treatment before being chlorinated and introduced into the pipeline simulator. Results showed that overall chlorine decay in the simulator was consistently dominated by wall reactions whose first-order rate constants were an order of magnitude higher than those for the bulk water. With free chlorine, the wall rate constants for ozonated and GAC-treated water were about twice those of conventional or RO-treated water. This behavior is believed due to the effect that changes in the organic content of water have on its ability to complex iron and the effect that changes in water conductivity have on pipe wall corrosion. Tests run with chloraminated water showed no statistically significant effect of treatment type and had wall rate constants that were only 40 to 70% as high as those using free chlorine. PMID:16806395

  16. Evaluation of short-term exposure to heated water and chlorine for control of the Asiatic clam (Corbicula fluminea)

    SciTech Connect

    Mattice, J.S.; McLean, R.B.; Burch, M.B.

    1982-01-01

    Based on the need for development of efficient procedures for prevention or control of fouling by the Asiatic clam, Corbicula fluminea, the response of these clams to chlorine in combination with rapid increases in water temperature was examined. Small clams were acclimated to 10 and 25/sup 0/C, and large clams were acclimated to 25/sup 0/C. Experiments with each of these acclimation groups consisted of variables of total residual chlorine concentration (0, 5, 7.5, and 10 mg/L) and test temperature (ambient and 3 test temperatures ranging from 35 to 46/sup 0/C). The periods of exposure to increased temperature and chlorine were 40 and 30 min respectively. Clam mortalities were related to water temperature but not to chlorine exposure. At high temperatures at least 50% of the clams remained open through the entire chlorine exposure period. At higher temperatures all of the clams remained open. Even when clams remained open for the entire 30-min chlorine exposure period, all clams were not killed. However, virtually all clams exposed to 41 to 43/sup 0/C water temperatures were killed whether open or closed during the exposure period. Death due to temperature shock is the logical conclusion from these data. Combined application of heated water and chlorine at the concentrations used is not more effective in killing Corbicula than is heated water alone. Current regulations on the concentration of chlorine in power plant effluents indicate that further studies of control of Corbicula using chlorine offer little likelihood for success. (ERB)

  17. 40 CFR 63.453 - Monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with 40 CFR 430.24, shall monitor the chlorine and hypochlorite application rates, in kg of bleaching... comply with the bleaching system requirements of § 63.445(c) or the sulfite pulping system requirements... the chlorine outlet concentration of each gas scrubber used to comply with the bleaching system...

  18. Bromate ion formation in dark chlorination and ultraviolet/chlorination processes for bromide-containing water.

    PubMed

    Huang, Xin; Gao, Naiyun; Deng, Yang

    2008-01-01

    Bormate (BrO3(-)) is a carcinogenic chemical produced in ozonation or chlorination of bromide-containing water. Although its formation in seawater with or without sunlight has been previously investigated, the formation of bromate in dilute solutions, particularly raw water for water treatment plant, is unknown. In this article, the results of bench scale tests to measure the formation rates of bromate formation in dilute solutions, including de-ionized water and raw water from Yangtze River, were presented in dark chlorination and ultraviolet (UV)/chlorination processes. And the effects of initial pH, initial concentration of NaOCl, and UV light intensity on bromate formation in UV/chlorination of the diluted solutions were investigated. Detectable bromate was formed in dark chlorination of the two water samples with a relatively slow production rate. Under routine disinfecting conditions, the amount of formed bromate is not likely to exceed the national standards (10 microg/L). UV irradiation enhanced the decay of free chlorine, and, simultaneously, 6.6%--32% of Br was oxidized to BrO3(-). And the formation of bromate exhibited three stages: rapid stage, slow stage and plateau. Under the experimental conditions (pH = 4.41--11.07, Ccl2 = 1.23--4.50 mg/L), low pH and high chlorine concentration favored the generation of bromate. High light intensity promoted the production rate of bromate, but decreased its total generation amount due to acceleration of chlorine decomposition. PMID:18574968

  19. Possible role of reactive chlorine in microbial antagonism and organic matter chlorination in terrestrial environments.

    PubMed

    Bengtson, Per; Bastviken, David; de Boer, Wietse; Oberg, Gunilla

    2009-06-01

    Several studies have demonstrated that extensive formation of organically bound chlorine occurs both in soil and in decaying plant material. Previous studies suggest that enzymatic formation of reactive chlorine outside cells is a major source. However, the ecological role of microbial-induced extracellular chlorination processes remains unclear. In the present paper, we assess whether or not the literature supports the hypothesis that extracellular chlorination is involved in direct antagonism against competitors for the same resources. Our review shows that it is by no means rare that biotic processes create conditions that render biocidal concentrations of reactive chlorine compounds, which suggest that extracellular production of reactive chlorine may have an important role in antagonistic microbial interactions. To test the validity, we searched the UniprotPK database for microorganisms that are known to produce haloperoxidases. It appeared that many of the identified haloperoxidases from terrestrial environments are originating from organisms that are associated with living plants or decomposing plant material. The results of the in silico screening were supported by various field and laboratory studies on natural chlorination. Hence, the ability to produce reactive chlorine seems to be especially common in environments that are known for antibiotic-mediated competition for resources (interference competition). Yet, the ability to produce haloperoxidases is also recorded, for example, for plant endosymbionts and parasites, and there is little or no empirical evidence that suggests that these organisms are antagonistic. PMID:19453612

  20. Two-photon excitation of chlorin-e6-C15 monomethyl ester for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Chen, Ping; Zhao, P. D.; Guo, P.; Lin, Lie; Liu, J. Wei; Yu, Q.

    2005-01-01

    Two-photon-induced fluorescence spectrum and lifetime of Chlorin-e6-C15 Monomethyl Ester in tetrahydrofura (THF) are experimentally examined with femtosecond laser pulses at 800 nm from a Ti:sapphire laser. The two-photon excited fluorescence spectra of the molecule are basically similar to those obtained by one-photon excitation. The lifetimes of two-photon and one-photon excitation fluorescence of this molecule in the solution are of the order of 5.2 ns and 4.8 ns respectively. Our experimental results indicate that the two-photon-induced photodynamic processes of Chlorin-e6-C15 Monomethyl Ester are similar to one-photon-induced photodynamic processes. The two-photon absorption cross section of the molecule is measured at 800 nm as about σ2' ~ 29.1 x 10-50 cm4 " s/photon. As an example for two-photon photodynamic therapy, we also further examine the cell-damaging effects of the Ester. Our preliminary results of cell viability test indicate that Chlorin-e6-C15 Monomethyl Ester can effectively damage the liver cancer cells BEL-7402 under two-photon irradiation. Our results suggest Chlorin-e6-C15 Monomethyl Ester may become a potential two-photon phototherapeutic agent.

  1. Effects of chlorine and chlorine dioxide on human rotavirus infectivity and genome stability.

    PubMed

    Xue, Bin; Jin, Min; Yang, Dong; Guo, Xuan; Chen, Zhaoli; Shen, Zhiqiang; Wang, Xinwei; Qiu, Zhigang; Wang, Jingfeng; Zhang, Bin; Li, Junwen

    2013-06-15

    Despite the health risks posed by waterborne human rotavirus (HRV), little information is available concerning the effectiveness of chlorine or chlorine dioxide (ClO2), two common disinfectants of public water sources, against HRV and their effects on its genome remain poorly understood. This study investigated the effects of chlorine and ClO2 on purified HRV by using cell culture and RT-PCR to assess virus infectivity and genetic integrity, respectively. The disinfection efficacy of ClO2 was found to be higher than that of chlorine. According to the efficiency factor Hom model, Ct value (mg/L min) ranges required for a 4-log reduction of HRV at 20 °C by chlorine and ClO2 were 5.55-5.59 and 1.21-2.47 mg/L min, respectively. Detection of the 11 HRV genome segments revealed that damage to the 1227-2354 bp of the VP4 gene was associated with the disappearance of viral infectivity by chlorine. However, no complete accordance between culturing and RT-PCR assays was observed after treatment of HRV with ClO2. These results collectively indicate that the current practice of chlorine disinfection may be inadequate to manage the risk of waterborne HRV infection, and offer the potential to monitor the infectivity of HRV adapting PCR-based protocols in chlorine disinfection. PMID:23591108

  2. 40 CFR 423.15 - New source performance standards (NSPS).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the monitoring in 40 CFR 122.11(b), compliance with the limitations for the 126 priority pollutants in... regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136... concentration (mg/l) Total residual chlorine 0.20 (2) Total residual chlorine may not be discharged from...

  3. 40 CFR 423.15 - New source performance standards (NSPS).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the monitoring in 40 CFR 122.11(b), compliance with the limitations for the 126 priority pollutants in... regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136... concentration (mg/l) Total residual chlorine 0.20 (2) Total residual chlorine may not be discharged from...

  4. 40 CFR 423.15 - New source performance standards (NSPS).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the monitoring in 40 CFR 122.11(b), compliance with the limitations for the 126 priority pollutants in... regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136... concentration (mg/l) Total residual chlorine 0.20 (2) Total residual chlorine may not be discharged from...

  5. 40 CFR 423.15 - New source performance standards (NSPS).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the monitoring in 40 CFR 122.11(b), compliance with the limitations for the 126 priority pollutants in... regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136... concentration (mg/l) Total residual chlorine 0.20 (2) Total residual chlorine may not be discharged from...

  6. 40 CFR 423.15 - New source performance standards (NSPS).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the monitoring in 40 CFR 122.11(b), compliance with the limitations for the 126 priority pollutants in... regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136... concentration (mg/l) Total residual chlorine 0.20 (2) Total residual chlorine may not be discharged from...

  7. Chlorine dioxide treatment for zebra mussel control

    SciTech Connect

    Rybarik, D.; Byron, J.; Germer, M.

    1995-06-01

    Chlorine is recognized and commonly used biocide for power plant cooling water and service water treatment programs, including the control of zebra mussels. Chlorine dioxide has recently become a popular method of zebra mussel control because of its economy, safety, environmental acceptability, and effectiveness when compared to other mussel control methods. This control technique was recently demonstrated at Dairyland Power Cooperative`s Alma Generating Station on the east bank of the upper Mississippi River in Alma, Wisconsin. The project was assisted with EPRI Tailored Collaboration Program funds. The Dairyland Power Alam Generating Station consists of five generating units that utilize raw, untreated Mississippi River water for condenser, circulating, and service water supplies. The first units were built in 1947, with the final and largest unit being completed in 1960. Total station generating capacity is 200 MW. Because of recent increases in the zebra mussel density at the station intake, Dairyland Power selected the team of Nalco and Rio Linda to perform a chlorine dioxide treatment of the station`s new water systems to eradicate and control the mussels before their presence created operational difficulties. This paper will present the results of the treatment including treatment theory, design and construction of the treatment system, the method of chlorine dioxide generation, treatment concentration, analytical methods o monitoring chlorine dioxide generation, residuals and trihalomethane (THM) concentrations, protocol for monitoring treatment mortality, and the effects of chlorine dioxide and detoxification on other water chemistry parameters and equipment materials. The goal of this paper is to inform and assist users with establishing consistent and uniform practices for safely utilizing and monitoring chlorine dioxide in the eradication and control of zebra mussels.

  8. Summary of airborne chlorine and hydrogen chloride gas measurements for August 20 and September 5, 1977 Voyager launches at Air Force Eastern Test Range, Florida

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Emerson, B. R., Jr.; Hudgins, C. H.

    1978-01-01

    Airborne chlorine and hydrogen chloride measurements were made in the tropospheric ground cloud following the Voyager launches of August 20 and September 5, 1977. The maximum observed hydrogen chloride concentration for both launches was about 25 to 30 parts per million (ppm) occurring typically 2 to 6 minutes after launch. By completion of the sampling mission (1-1/2 hours for August, 4-1/2 hours for September), the maximum in-cloud concentration decayed to about 1 to 2 ppm. Maximum observed chlorine concentrations were about 40 to 55 parts per billion (ppb) about 2 to 8 minutes after launch; by about 15 minutes after launch, chlorine concentrations were less than 10 ppb (detection limit). In-cloud chlorine concentrations were well below 1 percent of hydrogen chloride concentrations. The appendix of the report discusses the chlorine instrument and the laboratory evaluation of the detector.

  9. Water chlorination: An enigma for modern-day environmental chemists

    SciTech Connect

    Johnson, J.D.; Jolley, R.L.

    1987-01-01

    The challenge of modern-day water chlorination is to reap the benefits of chlorine's excellent disinfection efficacy while minimizing its environmental impacts and byproduct toxicity. Chemists, biologists, and engineers need to work together to identify, quantify, and use most effectively the disinfectant forms of chlorine to maximize disinfection, while at the same time they also need to identify, quantify, and minimize the toxic forms of by-products produced by chlorine's reactions with the organic compounds found in water. To the extent that this is possible, we can enjoy the benefits of chlorine disinfection and minimize the human and environmental impacts of chlorination by-products. 22 refs.

  10. Formation of Chlorination Byproducts and Their Emission Pathways in Chlorine Mediated Electro-Oxidation of Urine on Active and Nonactive Type Anodes.

    PubMed

    Zöllig, Hanspeter; Remmele, Annette; Fritzsche, Cristina; Morgenroth, Eberhard; Udert, Kai M

    2015-09-15

    Chlorination byproducts (CBPs) are harmful to human health and the environment. Their formation in chlorine mediated electro-oxidation is a concern for electrochemical urine treatment. We investigated the formation of chlorate, perchlorate, and organic chlorination byproducts (OCBPs) during galvanostatic (10, 15, 20 mA · cm(-2)) electro-oxidation of urine on boron-doped diamond (BDD) and thermally decomposed iridium oxide film (TDIROF) anodes. In the beginning of the batch experiments, the production of perchlorate was prevented by competing active chlorine and chlorate formation as well as by direct oxidation of organic substances. Perchlorate was only formed at higher specific charges (>17 Ah · L(-1) on BDD and >29 Ah · L(-1) on TDIROF) resulting in chlorate and perchlorate being the dominant CBPs (>90% of initial chloride). BDD produced mainly short chained OCBPs (dichloromethane, trichloromethane, and tetrachloromethane), whereas longer chained OCBPs (1,2-dichloropropane and 1,2-dichloroethane) were more frequently found on TDIROF. The OCBPs were primarily eliminated by electrochemical stripping: On BDD, this pathway accounted for 40% (dichloromethane) to 100% (tetrachloromethane) and on TDIROF for 90% (1,2-dichloroethane) to 100% (trichloromethane) of what was produced. A post-treatment of the liquid as well as the gas phase should be foreseen if CBP formation cannot be prevented by eliminating chloride or organic substances in a pretreatment. PMID:26214011

  11. Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

    PubMed

    Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

    2014-09-01

    Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water. PMID:25198851

  12. Temporal Decrease in Upper Atmospheric Chlorine

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Livesey, N. J.; Read, W. G.; Salawitch, R. J.; Waters, J. W.; Drouin, B.; MacKenzie, I. A.; Pumphrey, H. C.; Bernath, P.; Boone, C.; Nassar, R.; Montzka, S.; Elkins, J.; Cunnold, D.; Waugh, D.

    2006-01-01

    We report a steady decrease in the upper stratospheric and lower mesospheric abundances of hydrogen chloride (HCl) from August 2004 through January 2006, as measured by the Microwave Limb Sounder (MLS) aboard the Aura satellite. For 60(deg)S to 60(deg)N zonal means, the average yearly change in the 0.7 to 0.1 hPa (approx.50 to 65 km) region is -27 +/- 3 pptv/year, or -0.78 +/- 0.08 percent/year. This is consistent with surface abundance decrease rates (about 6 to 7 years earlier) in chlorine source gases. The MLS data confirm that international agreements to reduce global emissions of ozone-depleting industrial gases are leading to global decreases in the total gaseous chlorine burden. Tracking stratospheric HCl variations on a seasonal basis is now possible with MLS data. Inferred stratospheric total chlorine (CITOT) has a value of 3.60 ppbv at the beginning of 2006, with a (2-sigma) accuracy estimate of 7%; the stratospheric chlorine loading has decreased by about 43 pptv in the 18-month period studied here. We discuss the MLS HCl measurements in the context of other satellite-based HCl data, as well as expectations from surface chlorine data. A mean age of air of approx. 5.5 years and an age spectrum width of 2 years or less provide a fairly good fit to the ensemble of measurements.

  13. Chlorination of organophosphorus pesticides in natural waters.

    PubMed

    Acero, Juan L; Benítez, F Javier; Real, Francisco J; González, Manuel

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 degrees C and pH 7 were determined to be 110.9, 0.004 and 191.6 M(-1) s(-1) for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L(-1) was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety. PMID:17904287

  14. Accumulation of chlorinated benzenes in earthworms

    SciTech Connect

    Beyer, W.N.

    1996-12-31

    Chlorinated benzenes are widespread in the environment. Hexachlorobenzene, pentachlorobenzene and all isomers of dichlorobenzenes, trichlorobenzenes, and tetrachlorobenzenes, have been detected in fish, water, and sediments from the Great Lakes. They probably entered the water as leachates from chemical waste dumps and as effluents from manufacturing. Hexachlorobenzene and pentachlorobenzene are commonly present in Herring gull (Larus argentatus) eggs from the Great Lakes, and some of the isomers of trichlorobenzene and tetrachlorobenzene are occasionally detected at low concentrations. Hexachlorobenzene, which was formerly used as a fungicide, has been the most thoroughly studied chlorinated benzene, and has been detected in many species. Its use as a fungicide in the United States was canceled in 1984. Since about 1975 hexachlorobenzene has been formed mainly in the production of chlorinated solvents. It is highly persistent in the environment and some species are poisoned by hexachlorobenzene at very low chronic dietary exposures. As little as 1 ppm in the diet of mink (Mustela vison) reduced the birth weights of young, and 5 ppm in the diet of Japanese quail (Coturnix coturnix japonica) caused slight liver damage. This paper describes a long-term (26 wk) experiment relating the concentrations of chlorinated benzenes in earthworms to length of exposure and three 8 wk experiments relating concentration to the concentration in soil the soil organic matter content, and the degree of chlorination. 20 refs., 3 figs., 1 tab.

  15. Characterization and Application of a Chlorine Microelectrode for Measuring Monochloramine within a Biofilm

    EPA Science Inventory

    Chlorine microelectrodes with tip sizes of 5-15 μm were developed and used to measure biofilm monochloramine penetration profiles. The chlorine microelectrode showed response to total chlorine, including free chlorine, monochloramine, and dichloramine under various conditions. ...

  16. 40 CFR 60.2125 - How do I conduct the initial and annual performance test?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... octa-chlorinated isomer emitted using EPA Method 23 at 40 CFR part 60, appendix A-7. (2) Quantify...-through octa-chlorinated isomer emitted using EPA Method 23 at 40 CFR part 60, appendix A-7. (2) Quantify... of dioxins/furans emitted in terms of toxic equivalency. (h) Method 22 at 40 CFR part 60, appendix...

  17. 40 CFR 60.2125 - How do I conduct the initial and annual performance test?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... octa-chlorinated isomer emitted using EPA Method 23 at 40 CFR part 60, appendix A-7. (2) For each...-chlorinated isomer emitted using EPA Method 23 at 40 CFR part 60, appendix A-7. (2) Quantify isomers meeting...) Method 22 at 40 CFR part 60, appendix A-7 of this part must be used to determine compliance with...

  18. Modelling and control of potable water chlorination.

    PubMed

    Pastre, A; Mulholland, M; Brouckaert, C J; Buckler, C A; Le Lann, M V; Roustan, M; Naidoo, D; Mabeer, V

    2002-01-01

    The Umgeni Water Wiggins water treatment plant feeds the southern areas of Durban in South Africa and has a maximum treatment capacity of about 350 Ml/d. Two interconnected reservoirs at this facility hold treated water before it enters the distribution network. Because of the variable demand, the reservoir levels and residence times undergo considerable variation. This has a strong influence on the free chlorine concentration in the water leaving the reservoir, which should be 0.8 to 1.2 mg/l, to ensure an adequate disinfection potential within the network. This paper describes a model which accounts for the observed variations of chlorine concentration, and will form the basis of a predictive controller for the chlorine concentration in the outlet. PMID:12448458

  19. Alkaline dechlorination of chlorinated volatile organic compounds

    SciTech Connect

    Gu, B.; Siegrist, R.L.

    1996-06-01

    The vast majority of contaminated sites in the United States and abroad are contaminated with chlorinated volatile organic compounds (VOCs) such as trichloroethylene (TCE), trichloroethane (TCA), and chloroform. These VOCs are mobile and persistent in the subsurface and present serious health risks at trace concentrations. The goal of this project was to develop a new chemical treatment system that can rapidly and effectively degrade chlorinated VOCs. The system is based on our preliminary findings that strong alkalis such as sodium hydroxide (NaOH) can absorb and degrade TCE. The main objectives of this study were to determine the reaction rates between chlorinated VOCs, particularly TCE, and strong alkalis, to elucidate the reaction mechanisms and by-products, to optimize the chemical reactions under various experimental conditions, and to develop a laboratory bench- scale alkaline destruction column that can be used to destroy vapor- phase TCE.

  20. PROTOZOAN SOURCES OF SPONTANEOUS COLIFORM OCCURRENCE IN CHLORINATED DRINKING WATER

    EPA Science Inventory

    The spontaneous occurrence of coliforms in chlorinated drinking waters has resulted in concern over their potential source and mechanism(s) of introduction into water delivery systems. Previous observations related to protozoal resistance to chlorine coupled with the ingestion of...

  1. Study on chlorine removal from mixture of waste plastics.

    PubMed

    Kakuta, Yusuke; Hirano, Katsumi; Sugano, Motoyuki; Mashimo, Kiyoshi

    2008-01-01

    The recycling of waste plastics that include plastics that contain chlorine, such as polyvinyl chloride, is difficult because the chlorine leads to the corrosion of equipment. Then, the dechlorination method of waste plastics containing chlorine (CCWP) that consists of a series of melt process and hot water process was examined. CCWP was put into the melt process with coal tar (HOB) and converter dust (CD) to inhibit the diffusion of the chlorine-containing gas. The results indicated that iron oxide of the principal element of CD combines with chlorine eliminated from CCWP, and forms water-soluble iron chloride on the melt process. HOB dissolves or adsorbs a part of the chlorine during the melt process, and inhibits the diffusion of the chlorine-containing gas. Approximately 98% of the chlorine in the CCWP reacts with CD and forms iron chloride, which can be extracted on the hot water process. PMID:17482803

  2. EXPERIENCE WITH CHLORINE DIOXIDE AT DENVER'S REUSE PLANT

    EPA Science Inventory

    Researchers at Denver's reuse demonstration plant found that the effectiveness of chlorine dioxide treatment is critically dependent on the performance of the generator. Because high chlorine dioxide yields can be obtained even when excessive concentrations of undesirable by-prod...

  3. EFFECTS OF CHLORINATED SEAWATER ON DECAPOD CRUSTACEANS AND 'MULINIA' LARVAE

    EPA Science Inventory

    Eggs and larvae of decapod crustaceans and embryos of Mulinia lateralis were exposed to chlorinated seawater for varying periods in continuous flow systems. Mortality, developmental rate, and general behavior were recorded. Panopeus herbstii zoeae were more sensitive to chlorine-...

  4. The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system

    SciTech Connect

    Garrett, W.E. Jr.

    1995-06-01

    Continuous chlorination has been successfully used for the control of Corbicula at a nuclear power plant located on the Chattahoochee River in southeastern Alabama, since 1986. The purpose of this study was to investigate further minimization of chlorine usage and determine if chlorine dioxide is a feasible alternative. Four continuous biocide treatments were evaluated for macro and microfouling control effectiveness, operational feasibility, and environmental acceptability. One semi-continuous chlorination treatment was also evaluated for macrofouling control effectiveness. Higher treatment residuals were possible with chlorine dioxide than with chlorination due to the river discharge limitations. At the levels tested, continuous chlorine dioxide was significantly more effective in providing both macro and microfouling control. Semi-continuous chlorination was just as effective as continuous chlorination for controlling macrofouling. The Corbicula treatment programs that were tested should all provide sufficient control for zebra mussels. Chlorine dioxide was not as cost effective as chlorination for providing macrofouling control. The semi-continuous treatment save 50% on chemical usage and will allow for the simultaneous treatment of two service water systems. Chlorite levels produced during the chlorine dioxide treatments were found to be environmentally acceptable. Levels of trihalomethanes in the chlorinated service water were less than the maximum levels allowed in drinking water.

  5. Bromine and Chlorine Go Separate Ways

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph shows the relative concentrations of bromine and chlorine at various locations on Earth and Mars. Typically, bromine and chlorine stick together in a fixed ratio, as in martian meteorites and Earth seawater. But sometimes the elements split apart and their relative quantities diverge. This separation is usually caused by evaporation processes, as in the Dead Sea on Earth. On Mars, at Meridiani Planum and Gusev Crater, this split has been observed to an even greater degree than seen on Earth. This puzzling result is currently being further explored by Mars Exploration Rover scientists. Data for the Mars locations were taken by the rover's alpha particle X-ray spectrometer.

  6. Production of chlorine from chloride salts

    DOEpatents

    Rohrmann, Charles A.

    1981-01-01

    A process for converting chloride salts and sulfuric acid to sulfate salts and elemental chlorine is disclosed. A chloride salt and sulfuric acid are combined in a furnace where they react to produce a sulfate salt and hydrogen chloride. Hydrogen chloride from the furnace contacts a molten salt mixture containing an oxygen compound of vanadium, an alkali metal sulfate and an alkali metal pyrosulfate to recover elemental chlorine. In the absence of an oxygen-bearing gas during the contacting, the vanadium is reduced, but is regenerated to its active higher valence state by separately contacting the molten salt mixture with an oxygen-bearing gas.

  7. Determination of chlorine in silicate rocks

    USGS Publications Warehouse

    Peck, L.C.

    1959-01-01

    In a rapid accurate method for the determination of chlorine in silicate rocks, the rock powder is sintered with a sodium carbonate flux containing zinc oxide and magnesium carbonate. The sinter cake is leached with water, the resulting solution is filtered, and the filtrate is acidified with nitric acid. Chlorine is determined by titrating this solution with mercuric nitrate solution using sodium nitroprusside as the indicator. The titration is made in the dark with a beam of light shining through the solution. The end point of the titration is found by visually comparing the intensity of this beam of light with that of a similar beam of light in a reference solution.

  8. Chlorinated organic compounds produced by Fusarium graminearum.

    PubMed

    Ntushelo, Khayalethu

    2016-06-01

    Fusarium graminearum, a pathogen of wheat and maize, not only reduces grain yield and degrades quality but also produces mycotoxins in the infected grain. Focus has been on mycotoxins because of the human and animal health hazards associated with them. In addition to work done on mycotoxins, chemical profiling of F. graminearum to identify other compounds produced by this fungus remains critical. With chemical profiling of F. graminearum the entire chemistry of this fungus can be understood. The focus of this work was to identify chlorinated compounds produced by F. graminearum. Various chlorinated compounds were detected and their role in F. graminearum is yet to be understood. PMID:27165533

  9. Diurnal variation of stratospheric chlorine monoxide - A critical test of chlorine chemistry in the ozone layer

    NASA Technical Reports Server (NTRS)

    Solomon, P. M.; De Zafra, R.; Parrish, A.; Barrett, J. W.

    1984-01-01

    Ground-based observations of a mm-wave spectral line at 278 GHz have yielded stratospheric chlorine monoxide column density diurnal variation records which indicate that the mixing ratio and column density of this compound above 30 km are about 20 percent lower than model predictions based on 2.1 parts/billion of total stratospheric chlorine. The observed day-to-night variation is, however, in good agreement with recent model predictions, both confirming the existence of a nighttime reservoir for chlorine and verifying the predicted general rate of its storage and retrieval.

  10. A stable isotope approach for source apportionment of chlorinated ethene plumes at a complex multi-contamination events urban site.

    PubMed

    Nijenhuis, Ivonne; Schmidt, Marie; Pellegatti, Eleonora; Paramatti, Enrico; Richnow, Hans Hermann; Gargini, Alessandro

    2013-10-01

    The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in ¹³C (<-60‰) suggesting production lines which have used depleted methane for synthesis. The other source had typical carbon isotope compositions of >-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, ¹³C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas. PMID:24077332

  11. Inactivation of antibiotic resistance genes in municipal wastewater by chlorination, ultraviolet, and ozonation disinfection.

    PubMed

    Zhuang, Yao; Ren, Hongqiang; Geng, Jinju; Zhang, Yingying; Zhang, Yan; Ding, Lili; Xu, Ke

    2015-05-01

    This study investigated the inactivation of two antibiotic resistance genes (ARGs)-sul1 and tetG, and the integrase gene of class 1 integrons-intI1 by chlorination, ultraviolet (UV), and ozonation disinfection. Inactivation of sul1, tetG, and intI1 underwent increased doses of three disinfectors, and chlorine disinfection achieved more inactivation of ARGs and intI1 genes (chlorine dose of 160 mg/L with contact time of 120 min for 2.98-3.24 log reductions of ARGs) than UV irradiation (UV dose of 12,477 mJ/cm(2) for 2.48-2.74 log reductions of ARGs) and ozonation disinfection (ozonation dose of 177.6 mg/L for 1.68-2.55 log reductions of ARGs). The 16S rDNA was more efficiently removed than ARGs by ozone disinfection. The relative abundance of selected genes (normalized to 16S rDNA) increased during ozonation and with low doses of UV and chlorine disinfection. Inactivation of sul1 and tetG showed strong positive correlations with the inactivation of intI1 genes (for sul1, R (2)  = 0.929 with p < 0.01; for tetG, R (2)  = 0.885 with p < 0.01). Compared to other technologies (ultraviolet disinfection, ozonation disinfection, Fenton oxidation, and coagulation), chlorination is an alternative method to remove ARGs from wastewater effluents. At a chlorine dose of 40 mg/L with 60 min contact time, the selected genes inactivation efficiency could reach 1.65-2.28 log, and the cost was estimated at 0.041 yuan/m(3). PMID:25483976

  12. Chlorine: Undergraduate Research on an Element of Controversy

    NASA Astrophysics Data System (ADS)

    Chang, Hasok

    2009-04-01

    If chemical elements were people, chlorine would be a celebrity. Although intrinsically no more or less important than any other element, chlorine has had a knack of making headlines. The genre of "object biography" has been quite successful in popular science recently. We took this opportunity to write a "biographical" study of chlorine. Chlorine's wide range of interesting controversies is well suited for attracting and maintaining the enthusiasm of the diverse range of students we teach in our department.

  13. Chlorine gas: an evolving hazardous material threat and unconventional weapon.

    PubMed

    Jones, Robert; Wills, Brandon; Kang, Christopher

    2010-05-01

    Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. PMID:20823965

  14. Decay kinetics of free chlorine in fresh produce wash system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorinated water wash is a critical step employed in the production of fresh-cut produce. The efficacy of chlorinated water was affected largely by the concentration of active chlorine ingredients, which degrades due to the presence of microorganisms, as well as inorganic and organic matters. It is...

  15. 49 CFR 176.225 - Stowage of chlorine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must...

  16. 49 CFR 176.225 - Stowage of chlorine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must...

  17. 49 CFR 176.225 - Stowage of chlorine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must...

  18. 49 CFR 176.225 - Stowage of chlorine.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must...

  19. 49 CFR 176.225 - Stowage of chlorine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Stowage of chlorine. 176.225 Section 176.225 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Class 2 (Compressed Gas) Materials § 176.225 Stowage of chlorine. Chlorine (UN 1017) must...

  20. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    PubMed Central

    Jones, Robert; Wills, Brandon; Kang, Christopher

    2010-01-01

    Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. PMID:20823965

  1. EFFECT OF BROMIDE ION ON FORMATION OF HAAS DURING CHLORINATION

    EPA Science Inventory

    loacetic acids (HAAs) during chlorination and he effects of independent variables, including pH, reaction time, and chlorine dosage. Almost all of the indpendent loaetic acids (HAAs) during chlorin...designed to statistically evaluate the influence of bromide ion on the formatio...

  2. PRACTICAL APPLICATIONS OF CHLORINE DIOXIDE/FIELD DATA

    EPA Science Inventory

    Chlorine dioxide is an effective drinking water disinfectant. he major by-products of chlorine dioxide that are a concern, at this time are chlorite and chlorate. herefore, residual concentrations of these by-products should be kept as low as possible by efficient chlorine dioxid...

  3. Efficacy of copper and silver ions and reduced levels of free chlorine in inactivation of Legionella pneumophila.

    PubMed Central

    Landeen, L K; Yahya, M T; Gerba, C P

    1989-01-01

    Water disinfection systems utilizing electrolytically generated copper and silver ions (200 and 20, 400 and 40, or 800 and 80 micrograms/liter) and low levels of free chlorine (0.1 to 0.4 mg/liter) were evaluated at room (21 to 23 degrees C) and elevated (39 to 40 degrees C) temperatures in filtered well water (pH 7.3) for their efficacy in inactivating Legionella pneumophila (ATCC 33155). At room temperature, a contact time of at least 24 h was necessary for copper and silver (400 and 40 micrograms/liter) to achieve a 3-log10 reduction in bacterial numbers. As the copper and silver concentration increased to 800 and 80 micrograms/liter, the inactivation rate significantly (P less than or equal to 0.05) increased from K = 2.87 x 10(-3) to K = 7.50 x 10(-3) (log10 reduction per minute). In water systems with and without copper and silver (400 and 40 micrograms/liter), the inactivation rates significantly increased as the free chlorine concentration increased from 0.1 mg/liter (K = 0.397 log10 reduction per min) to 0.4 mg/liter (K = 1.047 log10 reduction per min). Compared to room temperature, no significant differences were observed when 0.2 mg of free chlorine per liter with and without 400 and 40 micrograms of copper and silver per liter was tested at 39 to 40 degrees C. All disinfection systems, regardless of temperature or free chlorine concentration, showed increase inactivation rates when 400 and 40 micrograms of copper and silver per liter was added; however, this trend was significant only at 0.4 mg of free chlorine per liter. PMID:2619303

  4. 40 CFR 63.453 - Monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with 40 CFR 430.24, shall monitor the chlorine and hypochlorite application rates, in kg of bleaching... degraded in the biological treatment system as specified in § 63.457(l), conduct the sampling and...

  5. Modelling Of Chlorine Inductive Discharges

    NASA Astrophysics Data System (ADS)

    Chabert P.; Despiau-Pujo, E.

    2010-07-01

    .02, which is much lower than the value predicted for stainless steel walls (? = 0.6). This is consistent with reactor wall contaminations classi- cally observed in such discharges. The plasma electronegativity decreases with RF power and increases with Cl2 content. At high pressure, the power absorption and distribution of charged particles become more localized below the quartz window. Although the experi- mental trends are well reproduced by the model, the calculated charged particle densities are systematically overestimated by a factor of 3-5. The reasons for this discrepancy are discussed in the paper. Experimental studies have also shown that low-pressure inductive discharges operating with electronegative gases are subject to instabilities near the transition between capacitive (E) and inductive (H) modes. A global model, consisting of two particle balance equations and one energy balance equation, has been previously proposed to describe the instability mechanism in SF6/ArSF6 (Lieberman et al. 1999). This model, which agrees qualitatively well with experimental observations, leaves significant quantitative differences. In this work, this global model is revisited with Cl2 as the feedstock gas (Despiau-Pujo and Chabert 2009). An alternative treatment of the inductive power deposition is evaluated and chlorine chemistry is included. Old and new models are systematically compared. The alternative inductive coupling description slightly modifies the results. The effect of gas chemistry is even more pronounced. The instability window is smaller in pressure and larger in absorbed power, the frequency is higher and the amplitudes of oscillations are reduced. The feedstock gas is weakly dissociated (~16%) and Cl2+ is the dominant positive ion, which is consistent with the moderate electron density during the instability cycle.

  6. ANALYSIS OF CHLORINATED ORGANIC COMPOUNDS FORMED DURING CHLORINATION OF WASTEWATER PRODUCTS

    EPA Science Inventory

    Chemical byproducts produced during the chlorination of municipal wastewater were examined in a study that employed several specially modified analytical methodologies. Volatile byproducts were examined by the use of gas chromatography with selective detectors and gas chromatogra...

  7. CHLORINE ABSORPTION IN S(IV) SOLUTIONS

    EPA Science Inventory

    The report gives results of measurements of the rate of Chlorine (Cl2) absorption into aqueous sulfite/bisulfite -- S(IV) -- solutions at ambient temperature using a highly characterized stirred-cell reactor. The reactor media were 0 to 10 mM S(IV) with pHs of 3.5-8.5. Experiment...

  8. CHLORINE DISINFECTION STUDIES OF ENCEPHALITOZOON (SEPTATA) INTESTINALIS

    EPA Science Inventory

    A reproducible standardized assay was designed to determine two infective doses for E.intestinalis, the TCID50 and the MID. These doses can be used to assess the potential effectiveness of chlorine disinfection and can also be used to assess other disinfection parameters and ant...

  9. CHLORINE ABSORPTION IN S(IV) SOLUTIONS

    EPA Science Inventory

    The rate of chlorine (Cl2) absorption into aqueous sulfite/bisulfite [S(IV)] solutions was measured at ambient temperature using a highly characterized stirred cell reactor. The reactor media were 0 to 10 mM S(IV) with pH ranging from 3.5 to 8.5. Experiments were performed using ...

  10. 46 CFR 151.50-31 - Chlorine.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... desired rate of discharge, provided the air or gas is oil-free and thoroughly dried by passing it over activated aluminum oxide, silica gel, or other acceptable drying agent, and provided the supply pressure is...-resistant to chlorine in either the gas or liquid phase. Cast or malleable iron shall not be used....