Removal of disinfection by-products formation potential by biologically intensified process

The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation(R 2=0.9562 and R 2=0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R 2=0.9782. In addition certain linear correlations between THMFP, HAAFP and UV 254 (R 2=0.855 and R 2=0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.

Removal characteristics of disinfection by-products formation potential by bioaugmentation activated carbon process

The high-active bacteria were screened from 8 dominant bacteria obtained from the natural water body,and then the bioaugmentation activated carbon was formed by hydraulic immobilization of the high-active bacteria. Plant-scale studies on removal characteristics of disinfection by-products formation potentials (DBPFP) by bioaugmentation activated carbon process were conducted for micro-polluted raw water treatment. The results show that the bioaugmentation activated carbon process has adopted better purification efficiency to THMFP and HAAFP than traditional biological activated carbon process,and that average removal efficiencies of THMFP and HAAFP can reach 35% and 39.7% during the test period,increasing by more than 10% compared with traditional biological activated carbon process. The removal efficiencies of THMFP and HAAFP are stable because of the biodegradation of the high-active bacteria and the adsorption of active carbon. The biodegradability of CHCl3 formation potential is better as compared with that of CHCl2Br and CHClBr2 formation potentials among THMFP,and high removal efficiency of CHCl3formation potential is obtained by bioaugmentation degradation of the high-active bacteria. The biodegradability of HAAFP is better in comparison with that of THMFP,and the chemical properties of HAAFP are propitious to adsorption of activated carbon. Thus,HAAFP is on predominance during the competitive removal process with THMFP.

Characterization of NOM and THM formation potential in eutrophic reservoir water

Resin adsorption technique with XAD-8 and XAD-4 was used to characterize the raw water from Erlong reservoir in Jilin province of China. The NOM chemical composition sequences of four organic fractions in the raw water, from high to low, are fulvic acid （FA） fraction, hydrophilic non-acid （HPINA） fraction, hydrophilic acid （HPIA） fraction, and humic acid （HA） fraction. Experimental results show that FA is the main precursor of THMFP among the four organic fractions. However, HA or hydrophobie acid exhibits the highest chlorination activity in forming THMs. It is also found that the value of FI/DOC or SUVA and the specific THMFP have better positive correlation. It is implied that certain source water has unique nature of NOM and DBPs.

Formation potential and analysis of 32 regulated and unregulated disinfection by-products: Two new simplified methods

Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products(DBPs). Multi-analyte methods based on mass spectrometry(MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources. In this study, two analytical methods were developed for the quantification of 32 regulated and unregulated DBPs. A purge and trap(P&T) coupled with gas chromatography mass spectrometry(GC-MS) method was optimized that automated sample pre-treatment and analyzed volatile and semi-volatile compounds, including trihalomethanes(THMs), iodinated trihalomethanes(I-THMs), haloacetonitriles(HANs), haloketones(HKTs) and halonitromethanes(HNMs). LOQs were between 0.02-0.4 μg/L for most DBPs except for 8 analytes that were in the low μg/L range. A second method with liquid chromatography(LC) tandem mass spectrometry(MS/MS) was developed for the quantification of 10 haloacetic acids(HAAs) with a simple clean-up and direct injection. The LC-MS/MS direct injection method has the lowest detection limits reported(0.2-0.5 μg/L). Both methods have a simple sample pre-treatment, which make it possible for routine analysis. Hyperchlorination and uniform formation conditions(UFC) formation potential tests with chlorine were evaluated with water samples containing high and low TOC. Hyperchlorination formation potential test maximized THMs and HAAs while UFC maximized HANs. Ascorbic acid was found to be an appropriate quencher for both analytical methods. Disinfected drinking water from four water utilities in Alberta, Canada were also evaluated.

Characterization of disinfection byproduct formation potential in 13 source waters in China

The formation potential of four trihalomethanes （THMFP） and seven haloacetic acids （HAA7FP） in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system （SDS） chlorination method. The specific ultraviolet absorbance （SUVA254： the ratio of UV254 to dissolved organic carbon （DOC））, which ranged between 0.9 and 5.0 L/（mg.m）, showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids （HAAs） should be of concern in some source waters. TCM （chloroform） and BDCM （bromodichloromethane） were the major THM constituents, while TCAA （trichloroacetic acid） and DCAA （dichloroacetic acid） were the major HAA species. Br-THM （brominated THM species） were much higher than Br- HAA （brominated HAA species）, and the formation of Br-DBP （Br-THM and Br-HAA） should be of concern when the bromide concentration is over 100 μg/L.

Carbonaceous and nitrogenous disinfection by-product formation in the surface and ground water treatment plants using Yellow River as water source

This work investigated the formation of carbonaceous and nitrogenous disinfection by-products （C-DBPs, N-DBPs） upon chlorination of water samples collected from a surface water and a ground water treatment plant （SWTP and GWTP） where the conventional treatment processes, i.e., coagulation, sedimentation, and filtration were employed. Twenty DBPs, including four trihalomethanes, nine haloacetic acids, seven N-DBPs （dichloroacetamide, trichloroacetamide, dichloroacetonitrile, trichloroacetonitrile, bromochloroace- tonitrile, dibromoacetonitrile and trichloronitromethane）, and eight volatile chlorinated compounds （dichloromethane （DCM）, 1,2-dichloroethane, tetrachloroethylene, chlorobenzene, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene and 1,2,4- trichlorobenzene） were detected in the two WTPs. The concentrations of these contaminants were all below their corresponding maximum contamination levels （MCLs） regulated by the Standards for Drinking Water Quality of China （GB5749-2006） except for DCM （17.1 ~tg/L detected vs. 20 μg/L MCL）. The SWTP had much higher concentrations of DBPs detected in the treated water as well as the DBP formation potentials tested in the filtered water than the GWTP, probably because more precursors （e.g., dissolved organic carbon, dissolved organic nitrogen） were present in the water source of the SWTE

Disinfection By-Products in Drinking Water, Recycled Water and Wastewater： Formation, Detection, Toxicity and Health Effects： Preface

The disinfection of drinking water was an outstanding（and perhaps the most important）public health achievement of the 20^（th） century.According to the United Nations World Health Organization,

Characteristics of typical dissolved black carbons and their influence on the formation of disinfection by-products in chlor(am)ination

Dissolved black carbon(DBC)released from biochar can be one of the potential disinfection by-products(DBPs)precursors in the dissolved organic matter pool.However,the physiochemical and structural properties of DBC and the effects on the development of DBPs and DBP formation potential(DBPFP)during the disinfection process remain unclear.In this study,the characteristics of two kinds of DBC,namely,animal-derived DBC(poultry litter DBC,PL-DBC)and plant-derived DBC(wheat straw DBC,WS-DBC),were investigated.The effects of different kinds of DBC on the evolution of DBPs and DBPFP in chlorine and chloramine disinfection processes were compared with natural organic matter(NOM).The results showed that the total DBPs concentrations derived from PL-DBC,WS-DBC and NOM were similar during chlorination(i.e.,61.23µg/L,64.59µg/L and 64.66µg/L,respectively)and chloramination(i.e.,44.63µg/L,44.42µg/L and 45.58µg/L,respectively).The lower total DBPs and DBPFP concentrations in chloramination could be attributed to the fact that the introduction of ammonia in chloramine inhibited the breaking of the bond between the disinfectant and the active group of the precursor.Additionally,DBC presented much lower total DBPFP concentrations than NOM in both chlorination and chloramination.However,both kinds of DBC tended to form more monochloroacetic acids and haloacetamides than NOM,which could result from the higher organic strength,higher protein matter,and nitrogen-rich soluble microbial products of DBC.

四种PPCPs在氯化消毒工艺中生成N-亚硝胺类消毒副产物的实验研究

目的实验观察药物及个人护理用品(PPCPs)进入水环境后,经氯化消毒工艺氧化后,对含氮消毒副产物N-亚硝胺生成势(NAs FP)的影响。方法选定雷尼替丁、尼扎替丁、氯苯那敏及多西拉敏四种常用药物作为前驱物,分别以次氯酸钠、一氯胺、二氯胺为消毒剂,模拟水处理工艺中的加氯程序。分析N-二甲基亚硝胺(NDMA)、N-二乙基亚硝胺(NDEA)、N-甲基乙基亚硝胺(NMEA)、N-二丙基亚硝胺(NDPA)、N-二丁基亚硝胺(NDBA)N-亚硝基吗啉(NMOR)、N-亚硝基哌啶(NPIP)、N-亚硝基吡咯烷(NPYR)8种NAs FP。结果四种药物在氯化消毒工艺中以NDMA为主要生成物质,同时伴有NMEA、NDEA、NMOR及NPIP生成,且经一氯胺消毒后NDMA生成势最高。雷尼替丁无论经次氯酸钠还是氯胺消毒,均呈现出最高的NDMA生成势。雷尼替丁经次氯酸钠氧化后还可以生成NPIP,其本身结构特征使其成为具有较高NAs FP的前驱物。结论四种PPCPs在氯化消毒工艺中均为生成NAs的前驱物,从源头上控制向环境中排放PPCPs或优化消毒处理工艺可有效控制NAs的生成。

Control of aliphatic halogenated DBP precursors with multiple drinking water treatment processes： Formation potential and integrated toxicity

The comprehensive control efficiency for the formation potentials（FPs） of a range of regulated and unregulated halogenated disinfection by-products（DBPs）（including carbonaceous DBPs（C-DBPs）, nitrogenous DBPs（N-DBPs）, and iodinated DBPs（I-DBPs）） with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment（coagulation–sedimentation, pre-sand filtration）, ozone-biological activated carbon（O_3-BAC） advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated.The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide,and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O_3-BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON.After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles（HANs）》haloacetamides（HAMs） 〉haloacetic acids（HAAs） 〉 trihalomethanes（THMs） 〉 halonitromethanes（HNMs） 》I-DBPs（I-HAMs and I-THMs）. I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored.

氨基酸在氯胺消毒过程中生成卤乙腈的潜能及Br-的影响

为有效去除饮用水中含氮类消毒副产物卤乙腈(HANs)避免它危害人体健康,研究了水中存在的六种氨基酸在氯胺消毒过程中生成HANs的潜能及Br-的存在、浓度变化对生成的影响。结果表明:六种氨基酸经氯胺消毒后均有HANs类物质生成,其中酪氨酸的生成HANs的潜能最大为0.002 1 mmol/L。Br-的存在对氨基酸在氯胺化过程中生成HANs具有明显的促进作用,特别是溴代HANs的总量有明显增加,其中酪氨酸生成的二溴乙腈(DBAN)和溴氯乙腈(BCAN)增加量最多是1.15μmol/L,谷氨酸生成的DBAN和BCAN增加量最少是0.28μmol/L。随着Br-浓度增加酪氨酸生成HANs总量先增加后减少至平缓,溴代HANs占HANs总量的比例明显增大。在Br-浓度为10 mg/L时,0.2 mmol/L的酪氨酸生成HANs总量最大为0.003 mmol/L。

Research progress of disinfection and disinfection by-products in China

Disinfection is an indispensable water treatment process for killing harmful pathogens and protecting human health. However, the disinfection has caused significant public concern due to the formation of toxic disinfection by-products(DBPs). Lots of studies on disinfection and DBPs have been performed in the world since 1974. Although related studies in China started in1980 s, a great progress has been achieved during the last three decades. Therefore, this review summarized the main achievements on disinfection and DPBs studies in China, which included:(1) the occurrence of DBPs in water of China,(2) the identification and detection methods of DBPs,(3) the formation mechanisms of DBPs during disinfection process,(4) the toxicological effects and epidemiological surveys of DBPs,(5) the control and management countermeasures of DBPs in water disinfection, and(6) the challenges and chances of DBPs studies in future. It is expected that this review would provide useful information and reference for optimizing disinfection process, reducing DBPs formation and protecting human health.

高级氧化技术控制消毒副产物生成势的研究进展

饮用水消毒副产物生成势(DBPsFP)及前体物的控制问题一直以来都是饮用水研究领域的热点,而近年来在饮用水中频繁检出的一些更高毒性的新型含氮消毒副产物,更引发了研究者的广泛关注。高级氧化技术是一类能高效降解饮用水中天然有机物等消毒副产物前体物的水处理方法。本文全面阐述了UV/H2O2、TiO2光催化氧化、O3/H2O2、催化臭氧氧化、O3/UV、Fenton法及类Fenton法等高级氧化技术控制DBPsFP的研究进展,并根据现有高级氧化技术控制DBPsFP研究中的一些不足之处,提出了DBPsFP高级氧化处理领域今后研究的主要方向和需解决的问题。

活性炭结合超滤及纳滤工艺深度处理饮用水的中试研究

金门岛内水库的富营养化程度严重,藻类所产生的臭味物质、有机碳及消毒副产物的浓度非常高,影响岛内民众健康。研究利用活性炭结合超滤及纳滤工艺,将甲基异莰醇-2、土臭素处理至嗅阈值以下,将不可挥发溶解性有机炭(NPDOC)从6.4mg/L降至0.2mg/L;三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)可分别从489μg/L和656μg/L去除至38μg/L及17.6μg/L,去除率分别为92%及97%。中试结果表明,各检测项目均符合台湾地区饮用水标准。由32位金门县自来水厂员工测试3种水的适饮性,其中经活性炭结合超滤及纳滤组合工艺处理后的水样水质为多数测试人员所接受。

南方某水源水中天然有机物的特点及氯胺对氯化消毒副产物的控制

在对天然有机物分类的基础上进行了水体中有机物的特性研究,并采用氯胺对不同特性有机物的氯化消毒副产物进行了控制研究。结果表明,疏水酸占有机物总量的24%,疏水中性物质占41%,疏水性有机物占67%;对于三卤甲烷类消毒副产物生成势,疏水酸所产生的最多,疏水碱次之,亲水酸最少;对于卤乙酸类消毒副产物生成势,疏水碱产生的三卤乙酸最多,其次为疏水酸,亲水酸最少。氯胺对不同类有机物氯化消毒副产物控制程度不同,氯胺对疏水中性物质控制三卤甲烷类消毒副产物最好,其次是疏水碱和亲水碱;对疏水酸的三卤甲烷生成量控制较弱,对亲水酸的控制效果最差;氯胺对亲水碱氯化产生卤乙酸的控制效果最好,其次是疏水碱,控制效果最差的为疏水中性物质。

涂铁铝砂对水中有机物去除效果研究

在实验室条件下,以石英砂为载体,制备了涂铁铝砂.研究表明,涂铁铝砂的表面物理化学性质比石英砂滤料有很大改善：比表面积是原石英砂滤料的10倍,等电点时的pH值由0.2-2.2提高到8.8;表面粗糙,孔隙增多;对有机物的静态吸附效果由石英砂的8%提高到100%,过滤时对有机物的去除率由9.5%提高至45.2%,对藻类藻毒素的去除效果也明显优于石英砂滤料.进水有机物浓度、pH值、浊度和空床停留时间是涂铁铝砂去除有机物的主要影响因素.涂铁铝砂对有机物的去除效率随过滤时间会逐渐衰减,用0.5 mol.L的NaOH溶液再生,可以使其恢复对有机物的去除能力.最后分析了涂铁铝砂去除有机物的作用机理.

O_3-BAC深度处理工艺对有机物及三氯乙醛生成潜能的去除

以我国南方某O_3-BAC深度处理工艺水厂为研究对象,对工艺过程中有机物及三氯乙醛生成潜能(CHFP)进行每月一次为期1年的监测,同时对温度较高的夏季水样予以极性分离,以明晰O_3-BAC深度处理工艺对有机物及CHFP的去除能力与工艺过程中有机物的极性变化等。结果表明,O_3-BAC深度处理工艺原水TOC、UV_(254)、CHFP均呈现一定的季节性变化趋势,高温季节(4~9月)相对较高,范围分别为1.03~2.13mg/L、0.024 1~0.053 5cm^(-1)、17.49~41.40μg/L;O_3-BAC深度处理工艺对TOC、UV_(254)、CHFP去除率范围分别为31.54%~58.83%、46.59%~79.53%、46.20%~75.24%,混凝沉淀和BAC单元在去除有机物和CHFP中起主要作用。此外,臭氧化作用增加了亲水性有机物含量使CHFP升高,同时亦强化了BAC单元对CHFP的去除作用。

水中环丙沙星(CPFX)氯化消毒副产物生成潜能分析

该文首次考察了水中环丙沙星在不同氯化条件下多种含碳及含氮消毒副产物(DBPs)的生成情况。试验发现氯化氟喹诺酮抗生素环丙沙星能够生成包括三氯甲烷、三氯乙烷、二氯乙腈、三氯硝基甲烷、三氯丙酮等多种氯代消毒副产物,且氯化时间、加氯量与氯化p H对DBPs的生成具有显著影响。投加不同浓度的Br-能够使氯化过程中以三氯甲烷为主的氯代消毒副产物生成量减少,而溴代消毒副产物生成量增多。试验为抗生素水源水污染的消毒副产物生成提供了理论依据。

污水厂出水DOM的分级及三卤甲烷生成势研究

研究目的在于调查寒冷季节城市污水处理厂出水中天然有机物化学组分分级,探讨各分级组分与消毒副产物生成潜能间之关系。采集污水厂二级出水,以三种不同树脂把污水厂出水中有机物分离成六类不同组分,其中A水厂含量最高的物质为亲水酸性物质(33%)而B水厂的疏水性中性物质含量最多约占总有机物的64%。从总体来看两水厂的疏水性物质含量大于亲水性物质含量,疏水性物质的三卤甲烷生成势也较大,是水体中消毒副产物的主要前驱物质。疏水性有机物质较多,代表受生活污水污染严重,得知该城市污水主要受民生污染较多。

典型胺类物质的消毒副产物生成潜能

在pH为8.0的磷酸盐缓冲体系中,加氯量为x（Cl2）：x（N）=8∶1、温度为（20±1）°C条件下测试甲胺、乙胺、二甲胺、甲基乙胺、二乙胺、苯胺和对氯苯胺等7种胺类物质的三卤甲烷、卤乙酸、卤乙腈、卤代酮、三氯硝基甲烷和水合氯醛等6类消毒副产物的生成潜能。结果表明,7种胺类物质的三卤甲烷、卤乙酸、卤乙腈、卤代酮、三氯硝基甲烷和水合氯醛的生成潜能分别为0.8~459.0 mmol/mol,13~35 mmol/mol,0.01~1.30 mmol/mol,0.001~0.013 mmol/mol,0.05~1.00 mmol/mol和0.06~39.00 mmol/mol;总消毒副产物潜能为14~480 mmol/mol,其中以三卤甲烷和卤乙酸两类占总消毒副产物生成量的99%以上（除在对氯苯胺中占87%以外）。由于二乙胺和对氯苯胺两种物质与氯的反应活性较高,消毒副产物生成潜能也最大。