Effect of oxygen deprivation on treatment processes in a full-scale drinking water biofilter

2015 ◽  
Vol 15 (4) ◽  
pp. 825-833 ◽  
Author(s):  
D. A. Søborg ◽  
I. L. Breda ◽  
L. Ramsay
Keyword(s):  
Drinking Water ◽  
Oxygen Deprivation ◽  
Full Scale ◽  
Water Levels ◽  
Raw Water ◽  
Filter Media ◽  
Deprivation Period ◽  
Treatment Processes ◽  
Effect Of Oxygen ◽  
Iron Manganese

Dissolved oxygen is critical for proper operation of waterworks that utilize anaerobic groundwater and rely on biofilters to remove iron, manganese and ammonium. In these biofilters, planned or inadvertent oxygen deprivation may occur for a variety of reasons. The water quality effects of oxygen deprivation on the function of drinking water biofilters, however, have not previously been reported. In this study, a 5-day oxygen deprivation period in full-scale biofilters was found to affect iron, manganese and ammonium concentrations differently. During the oxygen deprivation period, iron continued to be removed, although a greater depth of filter media was required to carry out the removal. Manganese oxide in filter media was mobilized, causing manganese water concentrations to increase well above raw water levels. The ammonium in the raw water passed through the biofilters unchanged, indicating the dependence of nitrification microorganisms on oxygen as their sole electron acceptor. Stringent national drinking water criteria were exceeded during the deprivation period but were once again met within hours after oxygenation was recommenced. Manganese and nitrite recovery to pre-deprivation concentrations, however, required days. The results illustrate the interdependence of treatment parameters and provide valuable practical information to waterworks that experience or plan oxygen stoppage.

Minimization of the Disinfection by-Product Precursors in Treated Waters Exposed to Ozone and Chlorine

2014 ◽  
Vol 884-885 ◽  
pp. 91-95
Author(s):  
Shang Chao Yue ◽  
Le Jun Zhao ◽  
Xiu Duo Wang ◽  
Qi Shan Wang ◽  
Feng Hua He
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Supply ◽  
River Water ◽  
Water Samples ◽  
Full Scale ◽  
Ultraviolet Absorbance ◽  
Treatment Processes ◽  
Removal Efficiencies

The objectives of this study were to investigate impact of preoxidation on disinfection by-product (DBP) precursors in drinking water via two different preoxidation methods. The full-scale study was conducted on surface river water in a water supply plant in Tianjin, China. Two treatment trains were performed, with prechlorination and preozonation as preoxidation methods, respectively. The water samples were collected on different stages along the treatment processes and analyzed by following organic parameters: dissolved organic carbon (DOC), UV254 and specific ultraviolet absorbance (SUVA). The results indicated that Train 2 with preozonation was more effective to reduce DBP precursors. Preozonation possessed an excellent ability in the removal of UV254 and SUVA, the removal efficiencies were 25.14% and 18.77%, respectively, comparing to the removal rates of 6.66% and 5.64% during prechlorination, separately.

Treatment of taste and odor material by oxidation and adsorption

2004 ◽  
Vol 49 (9) ◽  
pp. 289-295 ◽  
Author(s):  
S.-W. Jung ◽  
K.-H. Baek ◽  
M.-J. Yu
Keyword(s):  
Drinking Water ◽  
Raw Water ◽  
Initial Concentration ◽  
Blue Green Algae ◽  
Jar Test ◽  
Treatment Processes ◽  
Taste And Odor ◽  
Removal Efficiencies ◽  
Run Time ◽  
Lab Test

Massive blooms of blue-green algae in reservoirs produce the musty-earthy taste and odor, which are caused by compounds such as 2-MIB and geosmin. 2-MIB and geosmin are rarely removed by conventional water treatment. Their presence in the drinking water, even at low levels (ng/L), can be detected and it creates consumer complaints. So those concentrations have to be controlled as low as possible in the drinking water. The removals by oxidation (O3, Cl2, ClO2) and adsorption (PAC, filter/adsorber) were studied at laboratory and pilot plant (50 m3/d) to select suitable 2-MIB and geosmin treatment processes. The following conclusions were derived from the study. Both of the threshold odor levels for 2-MIB and geosmin appeared to be 30 ng/L as a consequence of a lab test. For any given PAC dosage in a jar-test, removal efficiencies of 2-MIB and geosmin were increased in proportion to PAC dosage and were independent of their initial concentration in raw water for the tested PAC dosages. In comparison of geosmin with 2-MIB, the adsorption efficiency of geosmin by PAC was superior to that of 2-MIB. The required PAC dosages to control below the threshold odor level were 30 mg /L for geosmin and 50 mg/L for 2-MIB at 100 ng/L of initial concentration. Removal efficiencies of odor materials by Cl2, ClO2, and O3 were very weak under the limited dosage (1.5 mg/L), however increased ozone dosage (3.8 mg O3/L) showed high removal efficiency (84.8% for 2-MIB) at contact time 6.4 minutes. According to the initial concentrations of 2-MIB and geosmin, their removal efficiencies by filter/adsorber differed from 25.7% to 88.4%. For all those, however, remaining concentrations of target materials in finished waters were maintained below 30 ng/L. The longer run-time given for the filter/adsorber, the higher the effluent concentration generated. So it is necessary that the run-time of the filter/adsorber be decreased, when 2-MIB or geosmin occurs in raw water.

An approach for determining the most critical among a suite of chemical contaminants at a drinking water intake

2013 ◽  
Vol 13 (3) ◽  
pp. 835-845
Author(s):  
Fei Chen ◽  
William B. Anderson ◽  
Peter M. Huck
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Intake ◽  
Treatment Plant ◽  
Quality Data ◽  
Exceedance Probability ◽  
Raw Water ◽  
Water Quality Data ◽  
Treatment Processes ◽  
Raw Water Quality

An integrated approach for the identification and assessment of the most critical chemical contaminant(s) at a drinking water intake has been developed. It involves the determination of a threshold or critical raw water concentration (CRWC) for target contaminants using the observed overall removal efficiency of a specific water treatment plant (WTP) and regulated drinking water concentrations for the target contaminants. The exceedance probability relative to the CRWC based on historical raw water quality monitoring data is then calculated. Finally, the integration of the raw water quality data and the overall efficiency of a particular WTP sequence allows for identification of the most critical contaminant(s) as well as an advance indication of which contaminants are most likely to challenge a plant. The proactive nature of this approach gives a utility the impetus and time to assess current treatment processes and potential alternatives. In addition, it was found that three- or four-parameter theoretical distributions are more appropriate than two-parameter probability distributions for the fitting of raw water quality data. This study reveals that the reliance on raw and/or treated water contaminant concentrations in isolation or on theoretical removals through treatment processes can, in some circumstances, be misguided.

scholarly journals Antibiotic resistance fate in the full-scale drinking water and municipal wastewater treatment processes: A review

2020 ◽  
Vol 26 (4) ◽  
pp. 200324-0
Author(s):  
Rui Gao ◽  
Minghao Sui
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Full Scale ◽  
Resistant Bacteria ◽  
Individual Treatment ◽  
Chemical Compositions ◽  
Treatment Processes ◽  
Water And Wastewater ◽  
Treated Drinking Water

Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been widely identified as emerging pollutants in various aquatic compartments. Concerns have been raised that the antibiotic resistance determinants may occur in treated drinking water and wastewater, weakening the therapeutic efficacy of antibiotics and so posing threat to public health. Most often, laboratory trials are conducted to assess the removal efficiency of ARB and ARGs in individual treatment processes (e.g., disinfection). However, the random variations of microbial distribution and chemical compositions in real-world environments cannot be entirely simulated, presumably leading to false-positive results as a consequence. It is therefore useful to provide a summary of recent advancements regarding the antibiotic resistance attenuation during full-scale water/wastewater treatments, which has not been adequately evaluated so far. In this review, the prevalence, proliferation and transmission of ARB and ARGs in urban water cycle, coupled with corresponding detection methods are presented as a short overview. The fate of ARB and ARGs in the sequential drinking water and wastewater processing units is critically summarized, the aim of which is to provide guidance for improving the current water treatment facilities to further reduce the antibiotic resistance in finished water.

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.

Speciation and seasonal variation of various disinfection by-products in a full-scale drinking water treatment plant in East China

2019 ◽  
Vol 19 (6) ◽  
pp. 1579-1586 ◽  
Author(s):  
Xiang-Ren Zhou ◽  
Yi-Li Lin ◽  
Tian-Yang Zhang ◽  
Bin Xu ◽  
Wen-Hai Chu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Full Scale ◽  
East China ◽  
Raw Water ◽  
Drinking Water Treatment Plant ◽  
By Products

Abstract The objective of this research was to study the occurrence and seasonal variations of disinfection by-products (DBPs), including traditional carbonaceous and emerging nitrogenous DBPs, in a full-scale drinking water treatment plant (DWTP) for nearly 2 years. The removal efficiencies of each DBP through the treatment processes were also investigated. This DWTP takes raw water from the Yangtze River in East China. The quality of the raw water used in this DWTP varied with different seasons. The results suggested that DBP concentrations of the finished water were higher in spring (82.33 ± 15.12 μg/L) and summer (117.29 ± 9.94 μg/L) with higher dissolved organic carbon (DOC) levels, but lower in autumn (41.10 ± 5.82 μg/L) and winter (78.47 ± 2.74 μg/L) with lower DOC levels. Due to the increase of bromide concentration in spring and winter, more toxic brominated DBPs increased obviously and took up a greater proportion. In this DWTP, DBP concentrations increased dramatically after pre-chlorination, especially in summer. It is noteworthy that the removal of DBPs during the subsequent treatment was more obvious in spring than in the other three seasons because the pH value is more beneficial to coagulation in spring.

The Trihalomethanes Formation Potential in Treated Waters Exposed to Ozone and Chlorine

2014 ◽  
Vol 700 ◽  
pp. 542-546
Author(s):  
Shan Chao Yue ◽  
Le Jun Zhao ◽  
Xiu Duo Wang ◽  
Qi Shan Wang ◽  
Feng Hua He
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Full Scale ◽  
Raw Water ◽  
Total Removal ◽  
Formation Potential ◽  
The Impact ◽  
Final Effluent ◽  
Trihalomethanes Formation

The present study was implemented to investigate the trihalomethanes formation potential (THMFP) in drinking water treatment and to determine the impact of preozonation on the reduction of Trihalomethanes (THMs). The full-scale examination was carried out, using Luan River as the raw water. Two different preoxidation methods, prechlorination and preozonation were performed. THMFP and THM species were analyzed. The investigation indicated that 18.72% of THMFP was removed during preozonation. Further study on the distribution of THM species showed a significant reduction of Chloroform and bromodichloromethane, 20.62% and 17.39% during preozonation, respectively. The result suggested that the application of preozonation process is an effective method for reducing THMs generation in drinking water treatment. In the final effluent, the total removal rates of THMFP were 47.49% after preozonation and 55.67% after prechlorination.

scholarly journals Comprehensive analysis of the start-up period of a full-scale drinking water biofilter provides guidance for optimization

2018 ◽  
Author(s):  
Loren Ramsay ◽  
Inês L. Lousinha Breda ◽  
Ditte A. Søborg
Keyword(s):  
Drinking Water ◽  
Filter Design ◽  
Holistic Approach ◽  
Full Scale ◽  
Filter Media ◽  
Time Frequency ◽  
Ammonium Removal ◽  
Start Up ◽  
Specific Order ◽  
The Many

Abstract. The use of biofilters to produce drinking water from anaerobic groundwater is widespread in some European countries. A major disadvantage of biofilters is the long start-up period required for virgin filter medium to become fully functional. Although individual aspects of biofilter start-up have previously been investigated, no comprehensive study in full-scale using inherent inoculation has previously been documented. A thorough investigation of a full-scale drinking water biofilter was carried out over 10 weeks of start-up. The many spatial and temporal changes taking place during start-up were documented using a holistic approach. In addition to collection of many samples over time (frequency) and space (filter depth), this study entailed the use of multiple sample media (water, backwash water and filter media) and multiple types of analyses (physical, chemical and microbiological). The decrease in filter effluent concentrations of individual substances to compliance levels followed a specific order that was shown to coincide with the spatial-temporal development of bacteria on the filter media. Due to the abiotic nature of the iron removal process, iron disappears first followed by substances that require growth of microorganisms: ammonium, with nitrite appearing briefly near the end of ammonium removal, then manganese. The thorough overall picture obtained by these efforts provides guidance for optimization and monitoring of the start-up. Guidance include to shorten the start-up by focusing on kick-start of the ammonium removal, to limit the monitoring burden to at-line measurements of ammonium in finished water samples supplemented with manual manganese measurements when ammonium removal is complete, and to improve filter design by isolating the removal processes in separate, smaller filters.

scholarly journals Comprehensive analysis of the start-up period of a full-scale drinking water biofilter provides guidance for optimization

2018 ◽  
Vol 11 (2) ◽  
pp. 87-100 ◽  
Author(s):  
Loren Ramsay ◽  
Inês L. Breda ◽  
Ditte A. Søborg
Keyword(s):  
Drinking Water ◽  
Filter Design ◽  
Holistic Approach ◽  
Full Scale ◽  
Filter Media ◽  
Time Frequency ◽  
Ammonium Removal ◽  
Start Up ◽  
Specific Order ◽  
The Many

Abstract. The use of biofilters to produce drinking water from anaerobic groundwater is widespread in some European countries. A major disadvantage of biofilters is the long start-up period required for virgin filter medium to become fully functional. Although individual aspects of biofilter start-up have previously been investigated, no comprehensive study in full scale using inherent inoculation has previously been documented. A thorough investigation of a full-scale drinking water biofilter was carried out over 10 weeks of start-up. The many spatial and temporal changes taking place during start-up were documented using a holistic approach. In addition to collection of many samples over time (frequency) and space (filter depth), this study entailed the use of multiple sample media (water, backwash water and filter media) and multiple types of analyses (physical, chemical and microbiological). The decrease in filter effluent concentrations of individual substances to compliance levels followed a specific order that was shown to coincide with the spatiotemporal development of bacteria on the filter media. Due to the abiotic nature of the iron removal process, iron disappears at the earliest in the start-up period followed by substances that require growth of microorganisms. Ammonium disappears next, with nitrite appearing briefly near the end of ammonium removal, followed by manganese. The thorough overall picture obtained by these efforts provides guidance for optimization and monitoring of the start-up. Guidance for optimization includes shortening the start-up by focusing on kick-starting the ammonium removal; limiting the monitoring burden (at-line measurements of ammonium in finished water supplemented with manual manganese measurements when ammonium removal is complete); and improving filter design by isolating the removal processes in separate, smaller filters.

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