O3/BAC对氯化消毒副产物的控制作用

采用臭氧化—生物活性炭(O3／BAC)深度处理工艺去除水中消毒副产物前质的试验结果表明，该工艺能够有效去除水中消毒副产物前质，可控制氯化消毒副产物的生成，其中主臭氧化对三卤甲烷前质和卤乙酸前质均具有很好的去除效果，生物活性炭对卤乙酸前质表现出较好的去除效果，但对三卤甲烷前质的去除效果有限；藻类、有机物等在滤层的累积使得砂滤池在同一工作周期中的不同阶段对水中三卤甲烷前质的去除效果有所不同，因而需要合理设置砂滤池的反冲洗周期。臭氧化—生物活性炭工艺充分发挥了臭氧化和生物活性炭两种技术的优点，并相互促进和补充，能够充分保障饮用水的安全性。     

MIEX技术控制饮用水消毒副产物的研究进展

MIEX技术及其组合工艺能有效控制DBPs的生成,在国外得到了广泛应用,而国内对该技术的相关研究才刚刚起步.为探讨MIEX技术控制消毒副产物生成的效能,并推动该技术在我国的研究与应用,比较分析了目前国际上MIEX技术及其组合工艺对不同水源水的应用情况.结果表明,MIEX技术能有效去除小分子有机物,对DOC和UV254的去除率可达80%和95%以上,对溴离子的去除率可达65%;MIEX技术作为预处理单元能减少后续氯化消毒或臭氧氧化的剂量,与混凝沉淀工艺组合时可最大程度地控制THMs和HAAs的生成量,且能节省60%左右的混凝刺;MIEX与粉末活性炭组合对有机物的去除有互补增强作用(对DOC的去除率达90%以上),与膜分离技术组合时对UV254的去除率高达95%以上(MIEX投加量为10 mL/L).因此MIEX技术是一种有效控制消毒副产物的新技术,具有很好的推广应用价值.     

生物活性炭与臭氧/活性炭工艺控制DBPs前体物比较

通过比较生物活性炭工艺和臭氧/活性炭工艺去除消毒副产物前体物的性能,分析了经两种工艺处理后生成消毒副产物的风险。结果表明:生物活性炭工艺和臭氧/活性炭工艺对TOC和UV254均有去除效果,但臭氧/活性炭工艺远优于生物活性炭工艺。生物活性炭工艺对三卤甲烷前体物的去除率可达25%以上,而臭氧/活性炭工艺的去除效果更为显著,去除率在40%以上,且以活性炭滤池去除为主。经加氯消毒后,臭氧/活性炭工艺出水三氯甲烷和三氯乙醛的生成量比生物活性炭工艺都有所降低。因此,臭氧/活性炭工艺相比于生物活性炭工艺更能有效降低生成消毒副产物的风险。     

蜂窝陶瓷催化臭氧氧化处理饮用水中试

在北京市某净水厂进行了臭氧催化氧化处理滤后水的中试，对各种操作条件下蜂窝陶瓷催化臭氧氧化／颗粒活性炭过滤工艺的净水效果进行了考察。结果表明，与臭氧单独氧化相比，臭氧催化氧化反应器中有较高的溶解性臭氧浓度，对天然有机物（NOM）及总有机物（TOC）的去除效果较好，三氯甲烷生成潜能（CHCl3FP）较低。臭氧催化氧化的后续活性炭滤柱上的生物量较多，出水TOC、UV254及CHCl3FP值也均低于臭氧单独氧化的后续活性炭滤柱出水。     

臭氧/氯消毒中藻类有机物生成消毒副产物的特征

饮用水源地藻华会释放大量藻类有机物(AOM),AOM与氯消毒剂反应生成的消毒副产物(DBPs)会给饮用水用户带来不容忽视的健康风险。为此,探究了臭氧/氯消毒对AOM结构和DBPs生成的影响。结果表明,臭氧氧化能有效去除AOM中芳香蛋白和酚类、叶绿素a、藻蓝蛋白结构物质,但是对腐殖酸类结构的去除效果相对较差。DBPs生成总量随臭氧投加浓度的升高而增加,其中主要是三氯甲烷(TCM);卤代乙腈和卤代酮的生成总量随臭氧投加浓度的变化趋势不明显。延长臭氧接触时间会明显增加1 h氯化中TCM的生成量,氯化24 h时DBPs生成总量与臭氧接触时间无关。在臭氧/氯消毒过程中,AOM的DBPs生成潜能低于天然有机物(NOM)。AOM有利于一溴一氯乙腈的生成,而NOM会生成更多的二氯乙腈。     

臭氧多相催化氧化技术在水厂深度处理中的应用

通过生产性对比试验考察了臭氧催化氧化技术用于给水深度处理时对有机物的去除效能.结果表明,相对于单纯的臭氧氧化,臭氧催化氧化明显地提高了对TOC及微量有机物的去除率,并使水中的剩余臭氧浓度降低了0.2 mg/L,有效地抑制了溴酸盐的生成.该技术可明显降低后续处理工艺的污染物负荷,并使有机物在活性炭上的吸附性能提高了近一倍,与生物活性炭联用后,对有机物的综合去除能力提高了14%～24%.臭氧催化氧化及其联用技术在兼顾有机物去除与臭氧化副产物控制方面具有明显的优势.     

南方某水厂臭氧/活性炭深度处理工艺运行效果

以南方地区微污染水源水为对象,研究臭氧/活性炭深度处理工艺对有机物综合指标UV(254)、COD(Mn)、TOC的去除效果以及对消毒副产物的控制效果,并结合三维荧光光谱技术分析溶解性有机物的荧光特性。结果表明,与常规处理工艺相比,增加臭氧/活性炭深度处理工艺后,对UV(254)、COD(Mn)、TOC、三卤甲烷前体物的去除率分别提高了47.05%、20.24%、31.11%、37.70%。三维荧光光谱分析结果表明,该地区微污染水源水主要由芳香性蛋白质类物质、溶解性微生物代谢产物类物质和富里酸类物质组成,臭氧/活性炭深度处理工艺对荧光溶解性有机物的去除效果明显。     

用UFC方法评价对消毒副产物前质的去除效果

目前经常采用的消毒副产物前质的评价方法有3种，即生成潜能（FP）试验、模拟管网（SDS）试验和标准生成势（UFC）试验。经比较发现FP试验所采用的培养条件与实际偏离较大；SDS试验的虽与实际最符，但不同时期、不同水源之间所得数据的可比性较差；UFC试验所采用的培养条件与实际生产的较为接近，无论在生成量还是在物种分布上，所得数据均与实际生产的较为符合。采用UFC方法评价了四种常用水处理工艺对THMs前质的去除效果。结果表明，常规处理工艺对THMs前质的去除效果较差，去除率仅为27％；在预臭氧投量为2．0mg／L的条件下，其对常规工艺去除THMs前质的效果没有明显的改善作用；活性炭吸附能较为有效地去除水中的THMs前质，去除率可达47％；臭氧-生物活性炭对THMs前质的去除效果最好，能够使出水的THMs前质含量降到90μg／L以下，去除率达到了75％。     

预处理强化生物活性炭工艺研究

研究了不同水处理组合工艺的除污染效能,包括化学预处理、常规处理、生物活性炭或臭氧生物活性炭技术的联用。试验结果表明,臭氧预氧化、高锰酸盐复合药剂（PPC）预氧化均能强化生物活性炭或臭氧生物活性炭工艺对各项指标的去除,可提高对浊度、UV254、CODMn的去除率;PPC预氧化与生物活性炭联用技术可强化AOC、BDOC的去除效果,达到生物稳定性的控制要求,是适合我国水厂改造的水处理技术。     

催化臭氧氧化联合BAC工艺深度处理石化废水

针对石化废水难降解的问题，采用活性炭作为臭氧氧化单元的催化剂，并串联生物活性炭(BAC)单元，从水质变化、有机物分子质量分布和有机物结构等角度解析催化臭氧氧化对石化废水中难降解有机物的降解特性，以及对后续BAC单元出水水质的影响机理。结果表明，活性炭催化对臭氧氧化去除COD和UV₂₅₄均有一定的促进作用，且对后续BAC单元去除COD和UV₂₅₄的促进效果更明显，其中，对UV₂₅₄的去除效果影响更大，当臭氧投加量为15和20 mg/L时，催化臭氧氧化对UV₂₅₄的去除率比臭氧氧化分别提升9.4%和11.5%，后续BAC单元对UV₂₅₄的去除率比无催化条件时分别提升17.0%和15.4%；催化条件对进水有机物分子质量分布的改变在O₃投加量为15 mg/L时更明显，相比臭氧氧化，催化臭氧氧化对进水中不可吹扫有机碳(NPOC)的去除率提升5.4%，出水中分子质量<1 ku的NPOC比例增加6%；进水经催化臭氧氧化后，有机物结构显著改变，酚类、链烷烃类及不饱和...     

不同净水工艺对含溴水体消毒副产物生成势的影响

以溴离子和有机物浓度不同的5个水厂原水和各工艺段出水为研究对象,考察了不同净水工艺对三卤甲烷(THMs)和卤乙酸(HAAs)这两类典型消毒副产物生成势和种类分布的影响。结果表明,仅采用常规处理工艺对THMs和HAAs生成势的控制效果不明显,而增设生物预处理和臭氧氧化预处理工艺能显著提高常规工艺对THMs和HAAs前体物的去除效果,臭氧/生物活性炭(O3/BAC)深度处理工艺能进一步去除THMs和HAAs的前体物。增设预处理和O3/BAC深度处理工艺,并采取砂滤池后置的净水工艺流程对THMs和HAAs生成势的控制效果最好。对于含溴水体,溴离子浓度越高,有机物中亲水性组分所占比例越高,经氯消毒后生成的溴代THMs和HAAs所占比例就越高。随着处理工艺流程的进行,THMs和HAAs的生成势逐渐降低,但是它们的溴结合因子逐渐增大,即毒性更大的溴代组分所占比例逐渐增大。     

Fate of N-nitrosodimethylamine, trihalomethane and haloacetic acid precursors in tertiary treatment including biofiltration

The presence of disinfection by-products (DBPs) such as trihalomethanes (THMs), haloacetic acids (HAAs) and N-nitrosamines in water is of great concern due to their adverse effects on human health. In this work, the removal of N-nitrosodimethylamine (NDMA), total THM and five HAA precursors from secondary effluent by biological activated carbon (BAC) is investigated at full and pilot scale. In the pilot plant two filter media, sand and granular activated carbon, are tested. In addition, we evaluate the influence of ozonation prior to BAC filtration on its performance. Among the bulk of NDMA precursors, the fate of four pharmaceuticals containing a dimethylamino moiety in the chemical structure are individually investigated. Both NDMA formation potential and each of the studied pharmaceuticals are dramatically reduced by the BAC even in the absence of main ozonation prior to the filtration. The low removal of NDMA precursors at the sand filtration in comparison to the removal of NDMA precursors at the BAC suggests that adsorption may play an important role on the removal of NDMA precursors by BAC. Contrary, the precursors for THM and HAA formation are reduced in both sand filtration and BAC indicating that the precursors for the formation of these DBPs are to some extent biodegradable.     

亚硝酸盐氮对臭氧氧化有机物的影响研究

在臭氧氧化处理微污染原水的工艺中，臭氧对有机物的去除效果与水中还原性无机物的含量有关。通过试验考察了水中NO2^--N对臭氧氧化有机物的影响。结果表明，水中较高浓度的NO2^--N可消耗臭氧投加量的40％左右，并降低了臭氧对THMs前体物的去除率，也影响其提高水中可生物降解有机物浓度的能力；碱度的增加可增强NO2^--N对臭氧的竞争利用，降低臭氧对TOC和UV254的去除率。     

Disinfection by-products and their precursors in a water treatment plant in North China: Seasonal changes and fraction analysis

A one-year-long monitoring project was conducted to assay the concentrations of THMs, HAAs and their formation potential along the conventional process in a water treatment plant in North China. Subsequent investigations of organic matter fractionation and the contribution of the algae to the precursor were also conducted to trace the source of the DBPs. The results showed that the concentration of DBPs and their formation potential varied with the seasons. The highest concentrations of THMs and the highest HAAs formation potential, each almost 500 microg/L, were detected in autumn and the lowest were in spring, no more than 100 microg/L. Both organic matter and algae were found to be important DBP precursors. The hydrophobic acid fraction in dissolved organic matter has the highest formation potential for both THM and HAA. Algae contribute about 20% to 50% of the total formation potential during an algal bloom. The efficiency of each unit process for DBPs and precursors was also assayed. Unfortunately, the conventional drinking water treatment process is limited in its efficiency for precursor removal. The pre-chlorination and filtration process had a negative effect on DBP or precursor removal.     

Low trihalomethane formation in Korean drinking water

Organics in water have the potential to generate harmful disinfection by-products (DBPs) such as trihalomethanes (THMs) during the chlorination process. To clarify the regulatory implications of Korean THMs levels which appear to be significantly lower than those in the US where the Stage 1 and 2 D/DBPs rule has been promulgated, the characteristics of THMs formation were investigated on five major river waters in Korea. Water samples were taken from 12 water treatment plants on five major rivers that serve as drinking water sources for more than 90% of the Korean population. Trihalomethane formation potential (THMFP), total organic halide formation potential (TOXFP) and ultraviolet absorbance at 254 nm (UV(254)) were determined and compared with those from US data. A survey of existing data [J Korean Soc Water Qual; 16(4) 2000b 431-443] provided evidence that THMs levels in treated drinking water in Korea were one-third of those reported in the US. The lower THMs levels were mainly attributable to the differences in the level and THMFP of dissolved organic carbon (DOC). The DOC levels and the THMFP normalized to DOC were approximately 60% of those in the US. Results which combined could quantitatively account for the lower THMs levels (i.e. 0.6 x 0.6 approximately 1/3) in Korea. The observed Korean THMs levels were over-predicted by the THMs model () developed in the US. The level of THMFP was found to be similar if normalized for aromaticity as measured by UV(254). These findings suggest that: (i) the case for more stringent THMs control is not likely to be a high priority among issues of drinking water quality in Korea; and (ii) significant variation of THMFP level may exist over different geographic regions; hence (iii) independent THMs models should be developed to make accurate predictions for different regions.     

太湖某饮用水厂嗅味物质迁移特征解析

针对近年来水源地嗅味物质频发、严重威胁饮用水水质安全的问题,对太湖某饮用水厂进行了从原水到出厂水的全流程检测,分析了原水中嗅味物质的来源、含量变化及其与水环境因子的相关性,并探究了其在水处理工艺中的去除规律。原水中的主要致嗅物质为β-紫罗兰酮(β-Ion)、2,4,6-三氯苯甲醚(TCA)、二甲基三硫醚(DMTS)以及β-环柠檬醛(β-cyc),其主要源于藻类活动以及有机物的降解。DMTS含量与TCA含量呈极显著正相关,且均与氨氮含量呈显著正相关;β-Ion含量与CODMn含量呈显著正相关,并与叶绿素a(Chl-a)含量和UV254值呈极显著正相关。在饮用水厂处理工艺中,臭氧和生物预处理对TCA和β-cyc有一定去除效果;生物活性炭滤池对主要嗅味物质具有较好的去除效果;超滤膜过滤可对DMTS与TCA进一步去除。另外,在预处理、原水长距离输送、臭氧处理和清水池储存等过程中均存在嗅味物质含量回升的问题,应受到重点关注。