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.

Cost-effective water treatment of polluted surface water by using direct filtration and granular activated carbon filtration

2002 ◽  
Vol 2 (1) ◽  
pp. 233-240 ◽  
Author(s):  
J. Cromphout ◽  
W. Rougge
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Direct Filtration ◽  
Carbon Filtration ◽  
Effective Water

In Harelbeke a Water Treatment Plant with a capacity of 15,000 m3/day, using Schelde river water has been in operation since April 1995. The treatment process comprises nitrification, dephosphatation by direct filtration, storage into a reservoir, direct filtration, granular activated carbon filtration and disinfection. The design of the three-layer direct filters was based on pilot experiments. The performance of the plant during the five years of operation is discussed. It was found that the removal of atrazin by activated carbon depends on the water temperature.

scholarly journals Assessing biofilm on biofilter media (granular activated carbon and anthracite) from a pilot scale drinking water treatment plant

2021 ◽  
Author(s):  
Nick Dimas
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Microbial Biofilms ◽  
Attachment Sites

Drinking Water Treatment Plants employ biofiltration systems to increase water quality through nutrient reduction. Microbial biofilms housed in biofilter media, are responsible for nutrient uptake and biodegradation. The purpose of this study was to re-evaluate the function and efficiency of biofilter media and investigate seasonal changes in the microbial populations. TOC and DO were more reduced in Granular Activated Carbon (GAC) media than in anthracite. Heterotrophic plate counts (HPC) were conducted to establish seasonal trends on microbial population. PCR-amplified 16S rRNA fragments were sequenced to compare microbial communities. Summer samples have higher HPC than winter samples. Summer samples yielded a reduction in microbial diversity and no detectable overlap with winter samples. Confocal microscopy conducted to qualitatively visualize the structure of biofilms was complemented by quantitative COMSTAT analysis showing GAC with double the biomass due to a greater level of attachment sites. GAC outcompetes anthracite in chemical adsorption and biological activity.

scholarly journals Assessing biofilm on biofilter media (granular activated carbon and anthracite) from a pilot scale drinking water treatment plant

2021 ◽  
Author(s):  
Nick Dimas
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Microbial Biofilms ◽  
Attachment Sites

Drinking Water Treatment Plants employ biofiltration systems to increase water quality through nutrient reduction. Microbial biofilms housed in biofilter media, are responsible for nutrient uptake and biodegradation. The purpose of this study was to re-evaluate the function and efficiency of biofilter media and investigate seasonal changes in the microbial populations. TOC and DO were more reduced in Granular Activated Carbon (GAC) media than in anthracite. Heterotrophic plate counts (HPC) were conducted to establish seasonal trends on microbial population. PCR-amplified 16S rRNA fragments were sequenced to compare microbial communities. Summer samples have higher HPC than winter samples. Summer samples yielded a reduction in microbial diversity and no detectable overlap with winter samples. Confocal microscopy conducted to qualitatively visualize the structure of biofilms was complemented by quantitative COMSTAT analysis showing GAC with double the biomass due to a greater level of attachment sites. GAC outcompetes anthracite in chemical adsorption and biological activity.

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

scholarly journals Pesticide removals in the nitrifying expanded-bed filter at drinking water treatment plant

2020 ◽  
Vol 15 (1) ◽  
pp. 1-13
Author(s):  
Nguyet Thi-Minh Dao ◽  
The-Anh Nguyen ◽  
Viet-Anh Nguyen ◽  
Mitsuharu Terashima ◽  
Hidenari Yasui
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Field Analysis ◽  
Expanded Bed ◽  
Biological Activated Carbon

The occurrence of pesticides even at low concentrations in drinking water sources might induce potential risks to public health. This study aimed to investigate the removal mechanisms of eight pesticides by the nitrifying expanded-bed filter using biological activated carbon media at the pretreatment of a drinking water plant. The field analysis demonstrated that four pesticides Flutolanil, Buprofezin, Chlorpyrifos, and Fenobucard, were removed at 82%, 55%, 54%, and 52% respectively, while others were not significantly removed. Under controlled laboratory conditions with continuous and batch experiments, the adsorption onto the biological activated carbon media was demonstrated to be the main removal pathway of the pesticides. The contribution of microorganisms to the pesticide removals was rather limited. The pesticide removals observed in the field reactor was speculated to be the adsorption on the suspended solids presented in the influent water. The obtained results highlighted the need to apply a more efficient and cost-effective technology to remove the pesticide in the drinking water treatment process. Keywords: biological activated carbon; drinking water treatment; nitrifying expanded-bed filter; pesticide removal.

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