Treating water containing elevated bromide and iodide levels with granular activated carbon and free chlorine: impacts on disinfection byproduct formation and calculated toxicity

2020 ◽  
Vol 6 (12) ◽  
pp. 3460-3475
Author(s):  
Chuhui Zhang ◽  
J. Clark Maness ◽  
Amy A. Cuthbertson ◽  
Susana Y. Kimura ◽  
Hannah K. Liberatore ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Free Chlorine ◽  
Disinfection Byproduct ◽  
Byproduct Formation

Granular activated carbon effectively controlled disinfection byproduct formation and calculated toxicity, especially at high influent bromide levels.

scholarly journals Metals releases and disinfection byproduct formation in domestic wells following shock chlorination

2010 ◽  
Vol 3 (1) ◽  
pp. 177-198
Author(s):  
M. Walker ◽  
J. Newman
Keyword(s):  
Trace Metals ◽  
Contact Time ◽  
Disinfection Byproducts ◽  
Oxidation Potential ◽  
Free Chlorine ◽  
Haloacetic Acids ◽  
Background Concentrations ◽  
Disinfection Byproduct ◽  
Byproduct Formation ◽  
By Products

Abstract. Shock chlorination is used for rapid disinfection to control pathogens and nuisance bacteria in domestic wells. A typical shock chlorination procedure involves adding sodium hypochlorite in liquid bleach solutions to achieve concentrations of free chlorine of up to 200 ppm in the standing water of a well. The change in pH and oxidation potential may bring trace metals from aquifer materials into solution and chlorine may react with dissolved organic carbon to form disinfection byproducts. We carried out experiments with four wells to observe and determine the persistence of increased concentrations of metals and disinfection byproducts. Water samples from shock chlorinated wells were analyzed for Pb, Cu, As, radionuclides and disinfection byproducts (haloacetic acids and trihalomethanes), immediately prior to treatment, after sufficient contact time with chlorine had elapsed, and at intervals determined by the number of casing volumes purged, for up to four times the well casing volume. Elevated concentrations of lead and copper dissipated in proportion to free chlorine (measured semi-quantitatively) during the purging process. Trihalomethanes and haloacetic acids were formed in wells during disinfection. In one of two wells tested, disinfection byproducts dissipated in proportion to free chlorine during purging. However, one well retained disinfection byproducts and free chlorine after four well volumes had been purged. Although metals returned to background concentrations in this well, disinfection byproducts remained elevated, though below the MCL, likely because purging volume was insufficient. Simple chlorine test strips may be a useful method for indicating when purging is adequate to remove metals and disinfection by-products mobilized and formed by shock chlorination.

scholarly journals Metals releases and disinfection byproduct formation in domestic wells following shock chlorination

2011 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M. Walker ◽  
J. Newman
Keyword(s):  
Trace Metals ◽  
Treatment Time ◽  
Disinfection Byproducts ◽  
Oxidation Potential ◽  
Free Chlorine ◽  
Haloacetic Acids ◽  
Background Concentrations ◽  
Disinfection Byproduct ◽  
Byproduct Formation ◽  
By Products

Abstract. Shock chlorination is used for rapid disinfection to control pathogens and nuisance bacteria in domestic wells. A typical shock chlorination procedure involves adding sodium hypochlorite in liquid bleach solutions to achieve concentrations of free chlorine of up to 200 mg L−1 in the standing water of a well. The change in pH and oxidation potential may bring trace metals from aquifer materials into solution and chlorine may react with dissolved organic carbon to form disinfection byproducts. We carried out experiments with four wells to observe and determine the persistence of increased concentrations of metals and disinfection byproducts. Water samples from shock chlorinated wells were analyzed for Pb, Cu, As, radionuclides and disinfection byproducts (haloacetic acids and trihalomethanes), immediately prior to treatment, after sufficient treatment time with chlorine had elapsed, and at intervals determined by the number of casing volumes purged, for up to four times the well casing volume. Elevated concentrations of lead and copper dissipated in proportion to free chlorine (measured semi-quantitatively) during the purging process. Trihalomethanes and haloacetic acids were formed in wells during disinfection. In one of two wells tested, disinfection byproducts dissipated in proportion to free chlorine during purging. However, one well retained disinfection byproducts and free chlorine after 4 WV had been purged. Although metals returned to background concentrations in this well, disinfection byproducts remained elevated, though below the MCL. This may have been due to well construction characteristics and interactions with aquifer materials. Simple chlorine test strips may be a useful method for indicating when purging is adequate to remove metals and disinfection by-products mobilized and formed by shock chlorination.

Reduction of aqueous free chlorine with granular activated carbon - pH and temperature effects

1977 ◽  
Vol 11 (8) ◽  
pp. 785-789 ◽  
Author(s):  
Makram T. Suidan ◽  
Vernon L. Snoeyink ◽  
Roger A. Schmitz
Keyword(s):  
Activated Carbon ◽  
Temperature Effects ◽  
Granular Activated Carbon ◽  
Free Chlorine

Effect of multiple GAC reactivations on disinfection byproduct precursor removal

2004 ◽  
Vol 4 (4) ◽  
pp. 71-78 ◽  
Author(s):  
D.H. Metz ◽  
J. DeMarco ◽  
R. Pohlman ◽  
F.S. Cannon ◽  
B.C. Moore
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
The Other ◽  
Disinfection Byproduct ◽  
Better Than

The objective of this study was to compare the adsorption capabilities of the virgin carbon to the twelve and five times reactivated granular activated carbon (GAC). From a water treatment plant operator's perspective, there were very few practical differences in adsorption among the carbons tested for total organic carbon (TOC) and disinfection byproduct (DBP) precursors. However, some overall trends were observed. The GAC that was regenerated 5 times (R5) generally showed greater DBP precursor adsorption than the other GACs especially at the beginning of the runs. In some cases the carbon that was reactivated 12/13 times (R12 and R13) adsorbed slightly less DBP precursors than the other GACs especially in the latter part of the runs. The virgin (V) carbon performed better than the other GACs relative to DBP precursor removal in the latter part of the runs.

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