scholarly journals Removal of chlorite from drinking water: laboratory and pilot scale studies to predict activated carbon performance at full scale

2017 ◽  
Vol 64 ◽  
pp. 165-172
Author(s):  
Sabrina Sorlini ◽  
Michela Biasibetti ◽  
Francesca Gialdini ◽  
Maria Cristina Collivignarelli
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Pilot Scale ◽  
Full Scale ◽  
Carbon Performance

scholarly journals Removal of oxidative stress and genotoxic activities during drinking water production by ozonation and granular activated carbon filtration

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Maria Yu ◽  
Elin Lavonen ◽  
Agneta Oskarsson ◽  
Johan Lundqvist
Keyword(s):  
Oxidative Stress ◽  
Drinking Water ◽  
Activated Carbon ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Full Scale ◽  
Raw Water ◽  
Treatment Efficiency ◽  
Drinking Water Production ◽  
Treatment Technologies

Abstract Background Bioanalytical tools have been shown to be useful in drinking water quality assessments. Here, we applied a panel of in vitro bioassays to assess the treatment efficiency of two pilot-scale treatments: ozonation and granular activated carbon (GAC) filtration at a drinking water treatment plant (DWTP). The pilot-scale systems were studied alongside a full-scale treatment process consisting of biological activated carbon (BAC) filtration, UV disinfection, and monochloramine dosing. Both systems were fed the same raw water treated with coagulation/flocculation/sedimentation and sand filtration. The endpoints studied were oxidative stress (Nrf2 activity), genotoxicity (micronuclei formations), aryl hydrocarbon receptor (AhR) activation, as well as estrogen receptor (ER) and androgen receptor (AR) activity. Results Nrf2, AhR, and ER activities and genotoxic effects were detected in the incoming raw water and variability was observed between the sampling events. Compared to most of the samples taken from the full-scale treatment system, lower Nrf2, AhR, and ER bioactivities as well as genotoxicity were observed in all samples from the pilot-scale systems across all sampling events. The most pronounced treatment effect was a 12-fold reduction in Nrf2 activity and a sixfold decrease in micronuclei formations following ozonation alone. GAC filtration alone resulted in sevenfold and fivefold reductions in Nrf2 activity and genotoxicity, respectively, in the same sampling event. Higher bioactivities were detected in most samples from the full-scale system suggesting a lack of treatment effect. No androgenic nor anti-androgenic activities were observed in any sample across all sampling events. Conclusions Using effect-based methods, we have shown the presence of bioactive chemicals in the raw water used for drinking water production, including oxidative stress, AhR and ER activities as well as genotoxicity. The currently used treatment technologies were unable to fully remove the observed bioactivities. Ozonation and GAC filtration showed a high treatment efficiency and were able to consistently remove the bioactivities observed in the incoming water. This is important knowledge for the optimization of existing drinking water treatment designs and the utilization of alternative treatment technologies.

Removal of algal taste and odour compounds by granular and biological activated carbon in full-scale water treatment plants

2018 ◽  
Vol 18 (5) ◽  
pp. 1531-1544 ◽  
Author(s):  
Aisha Faruqi ◽  
Milann Henderson ◽  
Rita K. Henderson ◽  
Richard Stuetz ◽  
Brendan Gladman ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Algal Blooms ◽  
Pilot Scale ◽  
Full Scale ◽  
Biologically Active ◽  
Removal Rates ◽  
Biological Activated Carbon ◽  
Treatment Processes ◽  
Water Treatment Plants ◽  
Service Life Modelling

Abstract The occurrence and severity of cyanobacterial and algal blooms in water supplies has been increasing due to the effects of eutrophication and climate change, resulting in more frequent taste and odour (T&O) events. Conventional treatment processes have been found to be inefficient in removing the two most commonly detected algal T&O compounds, geosmin and 2-methylisoborneol (MIB), though granular activated carbon (GAC) and biological activated carbon (BAC) contactors have achieved high T&O removal rates. Literature on the performance of GAC and BAC for T&O removal in full-scale treatment plants, however, is limited. This review collates and assesses pilot-scale and full-scale studies which focus on removal of geosmin and MIB, with the aim of understanding the factors which influence T&O removal and determining knowledge gaps in the use of GAC and BAC. Age and empty bed contact time (EBCT) were found to have a significant impact on GAC performance, with removal efficiency decreasing with increased age and increasing with longer EBCTs. BAC contactors have achieved higher removal rates than non-biologically active GAC contactors and were not impacted by age, EBCT and/or carbon type. From these observations, implementation of BAC for T&O removal would be favourable; however, further investigations are required to understand full-scale performance of BAC and service life modelling.

Pilot-scale UV/H2O2-BAC process for drinking water treatment – Analysis and comparison of different activated carbon columns

2020 ◽  
Vol 382 ◽  
pp. 123044 ◽  
Author(s):  
Zhenqi Du ◽  
Ruibao Jia ◽  
Congcong Li ◽  
Pengwei Cui ◽  
Wuchang Song ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Treatment Analysis

scholarly journals Effects of Backwashing on Granular Activated Carbon with Ammonium Removal Potential in a Full-Scale Drinking Water Purification Plant

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1830 ◽  
Author(s):  
Jia Niu ◽  
Ikuro Kasuga ◽  
Futoshi Kurisu ◽  
Hiroaki Furumai
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Purification ◽  
Granular Activated Carbon ◽  
Full Scale ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonium Removal ◽  
Before And After ◽  
Drinking Water Purification ◽  
Purification Plant

Granular activated carbon (GAC) has been widely introduced to advanced drinking water purification plants to remove organic matter and ammonium. Backwashing, which is the routine practice for GAC maintenance, is an important operational factor influencing the performance of GAC and its microbial biomass. In this study, the effects of backwashing on the ammonium removal potential of GAC were evaluated. In addition, abundances of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) on GAC were analyzed. GAC samples before and after backwashing were collected from a full-scale drinking water purification plant. Samplings were conducted before and after implementation of prechlorination of raw water. The results showed that the ammonium removal potential of the GAC increased by 12% after backwashing before prechlorination (p < 0.01). After implementing the prechlorination, the ammonium removal potential of the GAC decreased by 12% even after backwashing (p < 0.01). The AOA was predominant on the GAC in the two samplings. Regardless of prechlorination, the amounts of the AOA and the AOB remained at the same level before and after backwashing. Analysis of the backwashing water indicated that the amounts of the AOA and AOB washed out from the GAC were negligible (0.08%–0.26%) compared with their original amounts on the GAC. These results revealed the marginal role of backwashing on the biomass of ammonia oxidizers on GAC. However, the results also revealed that backwashing could have a negative impact on the ammonium removal potential of GAC during prechlorination.

Using Pilot-Scale Investigations to Estimate the Remaining Geosmin and MIB Removal Capacity of Full-Scale GAC-Capped Drinking Water Filters

2006 ◽  
Vol 41 (3) ◽  
pp. 296-306 ◽  
Author(s):  
Souleymane Ndiongue ◽  
William B. Anderson ◽  
Abhay Tadwalkar ◽  
John Rudnickas ◽  
Margaret Lin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Contact Time ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Full Scale ◽  
Removal Capacity ◽  
Treatment Facilities ◽  
The City ◽  
Water Filters ◽  
Pilot Tests

Abstract Pilot tests were conducted to investigate the removal of geosmin and 2-methylisoborneol (MIB) by new and semi-exhausted granular activated carbon (GAC) extracted from full-scale filters located in the City of Toronto's drinking water treatment facilities. Four pilot filters containing core-sampled GAC and new sand were fed with settled water from a full-scale plant and operated under conditions similar to those employed at full-scale. None of the pilot filters appeared to be capable of reducing geosmin and MIB concentrations to below the commonly cited threshold odour limits of 4 ng/L for geosmin and 9 ng/L for MIB at the influent levels tested. When operated at a 5-min empty bed contact time (EBCT) with geosmin influent concentrations in the range of about 70 to 110 ng/L, removals ranged from 10 to 38% in filters with 25 to 30 cm of used GAC. In the filter with 25 cm of new GAC, removal was 83%. When operated with a 7.5-min EBCT, the filter containing 95 cm of used bituminous GAC removed 78% of the geosmin present in the influent. For both geosmin and MIB, the effluent concentration and the amount removed increased as influent concentration increased, as was expected. In general, geosmin was better removed than MIB.

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.

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