Removal Of Disinfection By-products Research Articles

Adsorption, boiling or membrane filtration for disinfection by-product removal: How to make our drinking water safer?

Disinfection by-products (DBPs) generated in drinking water have become a global concern due to their potential harm to human health. Nevertheless, there are few studies about different point-of-use water treatments in household drinking water. The study aims to compare the effectiveness of three point-of-use water treatments: adsorption, boiling, and membrane filtration. The experimental results showed that the initial average concentration of volatile DBPs and non-volatile DBPs for tap water were 63.71 μg/L and 6.33 μg/L. The removal efficiency of DBPs for adsorption which were 75.6 % (the filter volumes from 0 L to 20 L) and 45.4 % (the filter volumes from 20 L to 50 L) during the service life of the filter element (50 L). Boiling had a high removal efficiency for volatile DBPs like trihalomethanes (THMs), haloacetaldehydes (HALs), haloacetonitriles (HANs), and haloketones (HKs) (90.5 %, 100 %, 100 %, and 100 %, respectively). However, boiling had a low removal efficiency which was 15 % in removing non-volatile DBPs like haloacetic acids (HAAs). Membrane filtration had a middle removal efficiency for THMs, HAAs, HALs, HKs, and HANs (45.3 %, 75.2 %, 46.5 %, 47.6 %, and 100 %, respectively). Through analysis of the correlation between dissolved organic matter (DOM) removal efficacy and DBP removal efficiency, it was found that the strongest correlation was observed between UV254 and DBP removal efficiency. Boiling showed a lower estimated cytotoxicity of DBPs compared to adsorption and membrane filtration. Cancer risk assessment of DBPs was below the specified risk range for three point-of-use water treatments. This study provides a reference for choosing point-of-use water treatments in household drinking water.

Peracetic acid as an alternative disinfectant for micropollutants degradation and disinfection byproducts control in outdoor swimming pools

Peracetic acid (PAA) has garnered significant interest as a novel alternative to chlorine-based disinfectants for water treatment due to its broad-spectrum antimicrobial activity and its ability of reactive species generation when exposed to UV light. However, limited studies have investigated micropollutant degradation in the presence of PAA under solar irradiation. This is the first study to comprehensively investigate the photodegradation of caffeine (CAF) and 4-methylbenzylidene camphor (4-MBC) and the removal of disinfection byproducts (DBPs) in the presence of PAA under simulated solar light. The study revealed that the photodegradation of CAF and 4-MBC was significantly enhanced in the presence of PAA, following pseudo-first-order kinetics (R2 > 0.98) with reaction rates (kobs) of 0.220 and 0.111 h-1, respectively. In addition, substantial reduction of 21 DBPs, including trihalomethanes, haloacetic acids and haloacetonitriles, and no DBPs formation were observed in the presence of PAA and simulated solar irradiation. The proportion of coexisting H2O2 in the PAA solution considerably influenced target compounds degradation. CAF and 4-MBC were degraded faster under acidic conditions than under alkaline conditions. Hydroxyl radicals (·OH) dominated the degradation of CAF at different pH values, while direct photolysis and other reactive species played a major role in the degradation of 4-MBC.

Differences in the degradation behavior of disinfection by-products in UV/PDS and UV/H2O2 processes and the effect of their chemical properties

In this work, sixteen typical chlorinated and brominated aromatic disinfection by-products (DBPs) were selected as examples to investigate their different degradation mechanisms initiated by HO• and SO4•-. Addition reactions were the main mode of degradation of DBPs by HO•, while SO4•- dominated H-abstraction reactions and single electron transfer reactions. Chlorinated compounds had higher reactivity than brominated compounds. Furthermore, substituents with stronger electron-donating effects promoted the electrophilic reaction of DBPs with the two radicals. In addition, we developed a model based on the chemical properties LUMO, fmax−, and hardness for predicting the average reaction energy barriers for the initial reactions of DBPs with HO• and SO4•-. The model had good predictive performance for the difficulty of degradation of different DPBs by HO• and SO4•-, with R2 values of 0.85 and 0.87, respectively. Through the degradation efficiency simulation, we found that longer reaction times, higher oxidant concentrations and lower pollutant concentrations were more favorable for the removal of DBPs. The UV/PDS process showed better degradation of DBPs than the UV/H2O2 process. In addition, most degradation products of DBPs exhibited less toxicity to aquatic organisms than their parent compounds. This study provided theoretical guidance for the degradation and removal of other aromatic DBPs at the molecular level.

Impact of boiling on chemical and physical processes for reduction of halomethanes, haloacetonitriles, and haloacetic acids in drinking water

Tap water is boiled by families across the globe in their daily life for cooking food and beverages, as well as for controlling some chlorine-resistant organisms to improve the water quality. However, the effects of boiling methods (heating temperature, heating modes, open or closed containers) on water quality, in particular the reduction of disinfection byproducts (DBPs), are unclear. This comprehensive research demonstrates that during the heating process, trihalomethanes (THMs) were markedly decreased, haloacetonitriles (HANs) were drastically reduced and sometimes completely removed, while haloacetic acids (HAAs) were reduced the least. Heating to boiling in open containers reduced DBPs concentrations more than heating in the closed containers. Residual chlorine from 0.1 to 5.0 mg/L did not affect the removal of HANs, but could increase concentrations of HAAs likely due to reaction of organic matter with chlorine at elevated temperatures. THMs demonstrated good removal at 0.1–1 mg/L residual chlorine, but less removal at 5 mg/L residual chlorine. Sodium chloride (salt), often added as seasoning agent in the process of family cooking, was found to have little effect on the removal of DBPs during cooking and boiling. Compared with the toxicity of DBPs in tap water, boiling could greatly reduce both the cytotoxicity and carcinogenicity through removal of DBPs. Consequently, boiling of tap water had a significant effect on reducing human exposure to DBPs and their associated toxicities.

Bibliometric analysis of disinfection by-product research trends in Türkiye

The goal of this study is to reveal the time dynamics of studies systematically and comprehensively on drinking water treatment and disinfection, as well as the situation in the literature, by using the bibliometric analysis method to examine scientific publications in the field of "Disinfection By-Products" between 2001 and 2022. The data gathered from the investigated articles is shown using the visual mapping approach. In this regard, the research provides for an evaluation of the disinfection by-products literature. The study's database contained 115 scientific papers retrieved from Web of Science. Istanbul Technical University is the most productive university with 23 published articles on Disinfection By-products, followed by Suleyman Demirel University with 18 published articles. Trihalomethanes, haloacetic acids are the most studied types of carbonaceous disinfection by-products in published articles, and N-nitrosodimethylamine is one of the most widely published nitrogenous disinfection by-products. The precursors of disinfection by-products or the removal of disinfection by-products are the two main focuses of the purpose of all studies. Coagulation, advanced oxidation processes and membrane processes constitute the methods used in the control of disinfection by-products. Brominated, and nitrogenous DBPs have attracted much attention due to their high toxicity. Future studies on disinfection by-products should focus on water quality standards, precursor controls, toxicity, and health effects. The necessity of bibliometric analysis of disinfection by-products is a necessity to fill the existing knowledge gaps in global and regional studies.

Potential and mechanism of disinfection by-products removal in drinking water by bubbling corona discharge

Disinfection by-products (DBPs) with significant teratogenic and carcinogenic properties have become a growing concern among the public. As an efficient and environmentally friendly technology, non-thermal plasma offers potential for removing emerging micro-pollutants. In this study, the degradation performance of bubbling corona discharge was evaluated on 24 halogenated alicyclic and aliphatic DBPs present in drinking water at concentrations ranging from ng/L to μg/L. The degradation of DBPs followed pseudo-first-order kinetics with rate constants (kobs) in the descending order of halonitromethanes (HNMs), halogenated benzoquinones (HBQs), haloacetonitriles, trihalomethanes (THMs), haloketones, halogenated aldehydes, and haloacetic acids (HAAs). THMs, HNMs, and HBQs were effectively removed within 5 min under a discharge power of 28 W. Degradation rates achieved by plasma treatment surpass those of other conventional treatment technologies. The required energy consumption was in the range of 5–30 kW·h/m3/order.Furthermore, the study investigated the effects of discharge power, initial concentration, and economic analysis on the degradation of four selected DBPs as representatives of mono-, di- and multi-carbon-containing DBPs, namely chloroform (TCM) and bromoform (TBM), tribromoacetic acid (TBAA), and 2,3,5,6-tetrachloro-1,4-benzoquinone (TetraC-BQ). Reactive radicals in the plasma system were investigated using electron paramagnetic resonance, optical emission spectroscopy, fluorimetry, and radical scavengers. Hydrated electrons and hydroxyl radicals played an important role in the removal of DBPs. The intermediates generated during the degradation of TCM, TBM, TBAA, and TetraC-BQ were identified, and the possible degradation pathways for mono- and binary C-DBPs and HBQs were deduced. The breakdown of HBQs did not produce secondary contamination with aliphatic DBPs. The carbon in DBPs was primarily converted to formic acid, acetic acid, and oxalic acid, and the halogens were mainly converted to halogen ions. Additionally, luminescent bacteria toxicity testing confirmed that plasma treatment could reduce the acute toxicity of water samples. These findings demonstrate the potential of plasma treatment as a post-treatment device at the household level.

Nano-techniques: a tool to prevent disinfection by-product formation in drinking water

Water, a vital component required by all living things, becomes more and more polluted as a result of globalisation and industrialisation. Currently, pathogenic microbes, emerging pollutants, industrial chemicals and waste are polluting all-natural water resources and transportation systems. Therefore, before usage, drinking water has to be treated. When water disinfectants react with the organic natural components found in source waters, they may unintentionally produce disinfection by-products (DBPs), which have a negative impact on the biological system. There is a need for the development of innovative water-treatment solutions since traditional drinking water treatment (DWT) does not reduce emerging contaminants. The main objective of this study is to give an overview of disinfection techniques, DBP generation, health consequences and environmental repercussions. Additionally, there are advancements in nanotechnology that have been made in drinking water system treatment for the prevention of DBP and contaminant removal. Further review describes the analysis of advanced DWT processes that can be employed for the removal and control of precursors and DBPs.

Formation of disinfection by-products within the drinking water production system and distribution network of a real case study

This work presents a collaboration between the so-called Gasset Service Association (responsible for providing drinking water to 100,000 inhabitants from a surface water reservoir) and researchers from the University of Castilla-La Mancha (Spain). The main aim of this work was providing a comprehensive characterization of the formation and removal of disinfection by-products in a real drinking water treatment plant (DWTP) and water distribution network. According to the results obtained, it can be stated that bromate is formed on the pre-oxidation stage and it is not eliminated throughout the DWTP; meanwhile, total organic carbon is partially removed on the clarification process. Moreover, it demonstrates the key role of the residence time and the type of water storage throughout the distribution network (either in pipes or in tanks) due to the combined effect of, at least, four overlapped mechanisms: THMs chemical generation, air stripping, hydrolysis and biological removal. This comprehensive view of the drinking water production and distribution network represents an excellent framework for allowing the improvement in the drinking water quality for a very common water production case study: a medium-size city fed by a surface water source.

Removal of disinfection byproducts through integrated adsorption and reductive degradation in a membrane-less electrochemical system

Proper control/removal of disinfection byproducts (DBPs) is important to drinking water safety and human health. In this study, a membrane-less electrochemical system was developed and investigated to remove DPBs through integrated adsorption and reduction by granular activated carbon (GAC)-based cathode. Representative DPBs including trihalomethanes and haloacetonitriles at drinking water concentrations were used for removal experiments. The proposed system achieved >70% removal of most DBPs in a batch mode. The comparison with control tests under either open circuit or hydrolysis demonstrated the advantages of electrochemical treatment, which not only realized higher DPBs removal but also extended GAC cathode lifetime. Such advantages were further demonstrated with continuous treatment. High dechlorination and debromination efficiencies were obtained in both batch (82.2 and 94.3%) and continuous (79.3 and 87.6%) reactors. DBPs removal was mainly contributed by the electrochemical reduction and adsorption by the GAC-based cathode, while anode showed little oxidizing effect on DBPs and halide ions. Dehalogenated products of chloroform and dichloroacetonitrile were identified with toxicity reduction. The energy consumption of the continuously operated system was estimated to be 0.28 to 0.16 kWh m−3. The proposed system has potential applications for wastewater reuse or further purification of drinking water.

Hydrolyzed polyacrylonitrile UF-membrane for surface and TAP water treatment: Influence on DBPs formation and removal

The integration of pre-treatment methods with low pressure-driven ultrafiltration (UF) has been found effective for reducing the formation of disinfection by-products (DBPs) in drinking water. In this study, a low dose peroxone (H2O2/O3) assisted alkaline hydrolyzed polyacrylonitrile (HPAN) UF-membrane system was explored, to determine its performance efficiency against two dissolved organic matter (DOM) sources and TAP water, specifically focusing the formation and removal of regulated DBPs. Increased hydrophilicity, enhanced incorporation of carboxyl groups, and decreased surface porosity were observed for the PAN membrane as a function of increased hydrolysis time. Filtration experiments involving humic acid (HA) and samples of real DOM sources displayed a high flux recovery (>90%) with the HPAN membrane. The initial flux for the optimized HPAN was found to be twice than that of the NF-3 membrane, irrespective of the DOM source. However, a relatively comparable removal efficiency was observed for both HPAN and NF-3 membranes in terms of organic matter and DBPs formation potential. Additionally, the H2O2/O3-HPAN system significantly reduced the aromatic and fluorescent content of the DOM by upto 70–80%, as represented by the DOC, UV254 and parallel factor analysis (PARAFAC) components. The fluorescence ratio C1/C2 showed a relatively greater reduction for soil-derived organic matter (SOM) as compared to the Olympic Lake (OL) water. Post-chlorination was found highly effective for the degradation of the humic-like DOM component (C1) than that of the fulvic and protein-like components. Moreover, the integration of H2O2/O3 with HPAN was able to remove 80% of the THMs and HAAs formation for both OL and SOM samples, together with a comparable reduction in DBP cytotoxicity. Interestingly, the HPAN membrane by reducing the TAP water DBPs upto 50%, fulfills the criteria of USEPA maximum contaminant level for drinking water.

An Opinion on the Removal of Disinfection Byproducts from Drinking Water

Ensuring drinking water quality is a key factor for public health and it is especially important given the increase in industrialization. Its quality is ensured by a water treatment process that includes a disinfection stage, mainly involving chlorination. However, by applying this disinfection method, unwanted disinfection byproducts (DBPs) are formed. These compounds have, in general, a negative impact on human health. Following this, the development of stricter regulations for drinking water quality standards has been conducted worldwide. Several techniques for the removal of DBPs have already been developed to prevent DBP formation or to reduce DBPs formed during disinfection. Nevertheless, controlling the water distribution systems after drinking water treatment is still important, since DBPs can reoccur along the distribution network. To achieve this, further research should be developed to efficiently monitor and allow the performance of the necessary actions to detect and control these contaminants throughout the water distribution system. Additionally, the most suitable places for sensing along the distribution system must be further assessed.

Removal and transformation of disinfection by-products in water during boiling treatment

Disinfection by-products (DBPs) remain an ongoing issue because of their widespread occurrence and toxicity. Boiling is the most popular household water treatment method and can effectively remove some DBPs. However, the transformation behavior of DBPs during boiling is still unclear, and the key contributors to toxicity have not been identified. In this study, the changes in the concentrations of DBPs in the single-DBP systems and the multi-DBP systems during boiling were monitored, and in-depth discussions on the removal and transformation of DBPs in both systems were carried out. The results showed that boiling was effective in removing volatile DBPs (over 90% for TCAL, TCAN, and DCAN, and over 60% for TCM), but ineffective for non-volatile DBPs (around 20% for TCAA and below 10% for DCAA and MCAA). By hydrolysis and decarboxylation, the transformation occurred among DBPs, i.e., 55% TCAL to TCM, followed by 23% DCAN to DCAA, 22% TCAN to TCAA, and 10% TCAA to TCM. The transformations were found to be significantly influenced by other co-existing DBPs. In multi-DBP systems, the transformations of DCAN to DCAA and TCAN to TCAA were both promoted, while the transformation of TCAN to TCAA was inhibited. Transformation and volatilization are the two processes responsible for DBP removal. Toxicity estimates indicated that boiling was effective in reducing the toxicity of DBPs and improving the safety of the water, despite the interconversion of DBPs in drinking water during boiling. This study emphasized the importance of studying the interconversion behaviors of DBPs in drinking water during boiling and provided practical information for end-use drinking water safety.

Challenges of point-of-use devices in purifying tap water: The growth of biofilm on filters and the formation of disinfection byproducts

Currently, polypropylene (PP) and granular activated carbon (GAC) are widely used as the filters in point-of-use devices (POUs). However, the effect of biofilms formation in aged filters and subsequent formation/removal of disinfection byproducts (DBPs) during the use of POUs on purifying tap water remains unclear. In this study, the influence of filter replace event and filter usage time on the removal of DBPs by pristine or aged filters, such as trihalomethanes (THMs) and haloacetic acids (HAAs), was investigated. Additionally, the effect of biofilms-attached PP filters and GAC filters on DBPs concentration in treated water was explored. The results showed that POUs effectively removed over 60% of THMs and HAAs from tap water, while the removal efficiency decreased with the operation time. The increase in usage time of PP filters led to elevated levels of DBPs. Moreover, the pristine pre-GAC filters removed 12.31% of THMs and 6.62% of HAAs, respectively, while aged GAC filters enhanced the removal of HAAs. SEM and high-throughput sequencing analysis confirmed the attached growth of biofilms on aged PP and GAC filters. The biofilms growth on PP filters led to the formation of THMs and HAAs, and the formed DBPs increased with increasing influent chlorine concentration, lengthened filters usage time and stagnation time. Nevertheless, the DBPs in effluent of biofilms-attached GAC filters increased with increasing influent chlorine concentration and filter usage time while decreased with stagnation time. These results indicated that growth of biofilms commonly observed in filters of POUs leads to the formation of DBPs and increases the risk of DBPs exposure to users of POU devices.

Investigation of the correlation between trihalomethane concentrations and socioeconomic factors in NY State

Recent environmental justice studies have found associations between low drinking water quality and socioeconomic indicators such as income and race. Trihalomethanes, probable human carcinogens, are commonly found disinfection by-products (DBPs) in public water systems (PWS). Although trihalomethanes are correlated with socioeconomic indicators, there is a knowledge gap regarding how the level of contaminants correlates with socioeconomic indicators and other physicochemical factors in specific regions. Therefore, we investigated the correlation between trihalomethane concentrations and socioeconomic factors in New York State with more practical and insightful data analysis and interpretation compared to those in previous studies by providing more detailed city-level data and water system characteristics affecting the correlation. We found a negative correlation between median household income and trihalomethane concentrations in the state. The communities served by PWS using groundwater sources had lower trihalomethane concentrations and higher household income, suggesting that water quality parameters contribute to the negative correlation between trihalomethanes and income levels. The inverse association between trihalomethanes and household income may indicate socioeconomic disparity regarding drinking water quality and the need for improved efforts to assist small- and medium-sized community water systems to lower DBP levels in New York State because small- or medium-sized systems may have fewer resources to apply DBP control and removal technologies compared to large systems.

Removal of algae and algogenic odor compounds via combined pre-chlorination and powdered activated carbon adsorption for source water pretreatment

This study investigated the combination sequence and time interval of chlorination and powdered activated carbon (PAC) adsorption for the control of algae inactivation, algogenic odor removal, and disinfection by-product (DBP) formation. Results indicated that pre-chlorination/post-PAC exhibited the highest algae removal efficiency in all sequential combinations of PAC adsorption and chlorination, while it had displayed slight effect on the removal of DBPs. The evaluated sequential combinations all had significant effect on the removal of odor. Nevertheless, prolonged time interval between chlorination and PAC adsorption exhibited enhanced control of algae and odor compounds in all experiments; with increasing time interval from 0 to 15 min in pre-chlorination/post-PAC process, the removal efficiency of Chl-a, algal cell viability, GSM, and 2-MIB increased by 46%, 15%, 15% and 23%, respectively. In the combined processes, the odor removal efficiency was positively correlated with PAC dosage but negatively correlated with chlorine dosage. Furthermore, PAC addition could effectively reduce the total DBP yields, especially the N-DBPs. This study can provide a better understanding of improving in-situ operation of the pre-chlorination and PAC dosing systems for source water pretreatment.

Removal of disinfection byproducts and toxicity of chlorinated water by post-treatments of ultraviolet/hydrogen peroxide and ultraviolet /peroxymonosulfate

Post-treatment of ultraviolet (UV) irradiation is not efficient in eliminating toxicity of chlorinated water. Removal of disinfection byproducts (DBPs) and toxicity of chlorinated water by UV/hydrogen peroxide (UV/H2O2) and UV/peroxymonosulfate (UV/PMS) was investigated. In the absence of bromide, adding H2O2 or PMS enhanced the removal of nitrogenous DBPs and total organic chlorine (TOCl) than UV alone (1200 mJ/cm2). UV/PMS decreased the cytotoxicity from 10.6 to 4.4 mg-Phenol/L and genotoxicity from 7.1 to 2.0 μg-4-NQO/L, more efficient than UV/H2O2. However, results were quite different in the presence of bromide. PMS led to the increased formation of total organic bromine (TOBr) in chlorinated water. UV/PMS was therefore less efficient in toxicity removal than UV/H2O2. In the presence of bromide, UV/H2O2 decreased the cytotoxicity and genotoxicity by 85% and 68%, while UV/PMS only removed the cytotoxicity and genotoxicity by 59% and 46%. In the UV/PMS process, SO4˙- was more efficient on toxicity removal than ˙OH. Contributions of UV irradiation, ˙OH and SO4˙- were 55%, 14% and 31% to cytotoxicity removal, and 49%, 15% and 36% to genotoxicity removal. This study demonstrated the feasibility of using UV/H2O2 and UV/PMS as post-treatments to enhance the removal of DBPs and toxicity of chlorinated water.

Flume and single-pass washing systems for fresh-cut produce processing: Disinfection by-products evaluation

Free chlorine is widely used in fresh-cut produce washing to minimize microbial cross-contamination, but its application can also lead to the formation of harmful disinfection byproducts (DBPs). This study compared DBPs in process water and washed produce during commercial operation. Samples of shredded lettuce and diced cabbages washed in chlorinated water in the traditional double-flume wash and novel immersion-free single-pass wash systems were collected at multiple time points and locations from the processing lines. A suite of 33 conventional and emerging DBPs, including 4 trihalomethanes (THMs), 9 haloacetic acids (HAAs), 9 nitrogenous DBPs (N-DBPs), and 11 carbonaceous DBPs (C-DBPs), were investigated. Overall, N-DBPs and HAAs dominated the concentration of detected DBPs. Wash water in the flumes contained 7–111 folds higher DBP levels compared to that in the single-pass system, with the abundance of DBPs following the order of N-DBPs > HAAs > C-DBPs > THMs. DBPs were detected on washed produce, presenting primarily in the forms of N-DBPs and HAAs followed by C-DBPs and THMs. While higher levels of DBPs were detected in flume-washed produce, the final potable water rinse significantly reduced the DBP concentration in these products. The concentrations of THMs and HAAs on these washed products were used to estimate potential exposure via consumption of fresh-cut produce and the levels were below the daily allowable exposure for drinking water standard established by the U.S. Environmental Protection Agency. The detected high concentration and potential toxicity of N-DBPs indicate the need for further research. The findings of this study advance the understanding of the formation and removal of DBPs during wash processes, and identify additional research opportunities for further reduction in DBPs and food safety improvement.

In-situ, facile and green preparation of nanoscale silver supported on activated carbon: Disinfection properties and removal of inorganic DBPs from drinking water

Activated carbon (AC) was prepared from date palm leaves by phosphoric acid activation. The factors affecting the carbon percentage yield such as phosphoric acid concentration, synthesis temperature, and heating time were studied. The prepared AC was studied by chemical analysis of the functional groups on its surface. The prepared AC was decorated with silver nanoparticles (Ag NPs) by in-situ reduction of adsorbed silver ion. Silver ions were introduced on carbon surface by adsorption and ion exchange. Characterization of the prepared AC was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), infra-red spectroscopy (IR), and thermogravimetric analysis (TGA). Results showed that silver ions are impregnated and reduced to Ago NPs with sizes between 30 and 50 nm on the surface of AC. The disinfection properties of Ag-loaded AC were tested for EscherichiaColi and Staphylococci bacteria. The removal of some inorganic disinfection by products (DBPs) including iodate, chlorate, chlorite, and bromate were tested. The results showed that the prepared AC-Ag is effective for antibacterial disinfection and inorganic anions removal applications.

Disinfection By-products in Drinking Water and Their Control Strategies: A Review

Disinfection by-products(DBPs) are secondary pollutants generated by the reaction of disinfectants with organic or inorganic precursors during drinking water disinfection. DBPs have received considerable global attention due to their carcinogenic, teratogenic, and mutagenic characteristics. Focusing on drinking water, this paper introduces the main classification and research history of DBPs, and then summarizes the concentration levels of common DBPs in drinking water, and DBPs regulatory compliance in global drinking water standards. Further, the control strategies for DBPs in drinking water, including source control, process control, DBPs removal and integrated control are introduced together with the advantages and disadvantages. Finally, a summary and review of the current level and future trends of DBPs research in China are presented with the proposed control strategies. On the one hand, when evaluating the control effect of a process or technology, the DBPs concentration and comprehensive toxicity should be considered; on the other hand, in order to realize the efficient control of DBPs in drinking water, the focus should be on the integrated methods coupling different DBPs control methods.

Low Cost Activated Carbon for Removal of NOM and DBPs: Optimization and Comparison

Higher concentrations of disinfection byproducts (DBPs) in small water systems have been a challenge. Adsorption by tailored activated carbon (AC), developed from waste materials of a pulp and paper company using optimization of chemical activation by nitric acid followed by physical activation and metal coating, was tested for the removal of natural organic matter from water using synthetic and natural water. AC was coated with aluminum and iron salts in a ratio of 0.25 to 10.0% of metal: AC (wt:wt%). The optimization of dosage, pH, and time was performed to achieve the highest adsorption capacity. The modified AC of 0.75% Fe-AC and 1.0% Al-AC showed 35–44% improvement in DOC removal from natural water. An enhancement of 40.7% in THMs removal and 77.1% in HAAs removal, compared to non-modified, AC were achieved. The pseudo-second order was the best fitted kinetic model for DOC removal, representing a physiochemical mechanism of adsorption.