高锰酸钾预氧化-强化混凝控制饮用水消毒副产物的研究

以天津市生活饮用水为对象,分别实验研究对比了单独高锰酸钾预氧化、高锰酸钾预氧化-强化混凝对饮用水浊度、有机物及DBPs产生量的影响。结果表明,与传统预氯化相比:高锰酸钾预氧化,UV254和DOC去除率分别在7.0%~10.35%和7.8%~10.4%之间,THMs和HAAs减少率分别在30%~33%和19%~22%之间。高锰酸钾预氧化-强化混凝,DOC和UV254去除效率分别是40.5%和63.3%,出水THMs和HAAs分别47.8、76.8μg/L,减少率分别达到61.3%、50.2%。高锰酸钾预氧化-强化混凝可达到减少消毒副产物DBPs的产生以及去浊的目的。     

预臭氧化工艺处理低温低浊水的应用研究

通过进行预臭氧化-紫外/氯工艺处理低温低浊期水源的生产性试验,分别对各处理单元出水pH、浊度、DOC和UV254进行了测定。结果表明,在低温低浊期,整套工艺对浊度、DOC和UV254的平均去除率分别为93.83%、29.38%和57.20%。此外,预臭氧化单元对pH及去除浊度、DOC和UV254也有一定的影响。预臭氧化单元可有效降低UV254,但对浊度和DOC的去除效果不明显。     

臭氧联合混凝去除长江源水中有机污染物的小试研究

以长江重庆段水质为研究对象,考察臭氧对混凝去除水中有机污染物的影响。结果表明,臭氧预氧化后,TOC、UV254的去除率分别为2.5%、11.0%,说明臭氧可以部分彻底氧化去除水中有机物,预氧化后有机物的结构改变比较明显;相比于单独混凝,臭氧联合混凝使TOC和UV254的去除率分别提高了4.9～5.3和12.1～14.2个百分点,臭氧预氧化可以强化混凝对TOC和UV254的去除;臭氧预氧后各个分子段有机物的分布改变比较明显,相对分子质量大于3×103的有机物明显减少,相对分子质量小于3×103的有机物明显增加。相比于单独混凝,臭氧联合混凝主要提高了相对分子质量大于3×103的有机物去除率,降低了相对分子质量小于3×103有机物的去除率。     

臭氧组合工艺去除黄浦江原水中有机物

采用预臭氧化-常规处理-后臭氧化-生物活性炭深度处理工艺对黄浦江原水进行了中试试验,研究结果表明该工艺对去除有机物方面有良好效果,CODMn、UV254、DOC、AOC的总体去除率分别是62.3%、91.8%、63.7%、27%.臭氧氧化不能彻底去除有机物,但通过活性炭的协调作用可将其有效去除.     

臭氧活性炭联合工艺去除微污染水中有机物

采用臭氧活性炭联合工艺(O3+BAC)对以长江为水源的某水厂砂滤水进行深度处理。试验结果表明,该工艺对水中有机物有稳定的去除效果,在臭氧投加量为1mg/L,活性炭空床接触时间为8.6min时,对CODMn,UV254,DOC,THMEP(三氯甲烷生成势)和AOC(可同化有机碳)的平均去除率分别为32%,40%,22%,19%,7%。在DOC较低的情况下,三氯甲烷生成势与UV254有较好的正相关性。     

预氧化强化混凝处理引汉济渭工程受水区不同掺混比水源水

引汉济渭工程通水后，黑河原水与汉江原水将共同作为西安市饮用水水源，且水厂进水中两种原水掺混比例会随引水工程运行调度而改变。本文重点考察了两种原水不同掺混比例下预氧化强化混凝工艺对水中有机物的去除效果。在两处水源以10:0、8:2、2:8、0:10比例掺混条件下，探明了高锰酸钾、高铁酸钾和二氧化氯预氧化强化混凝去除水中有机物的最佳浓度。结果表明，高铁酸钾预氧化-混凝效果最好，四种掺混比下高铁酸钾最佳投药量分别为0.8、0.8、1.0、1.0 mg/L。同等掺混比例和最佳投药量下，高铁酸钾对DOC去除率比高锰酸钾高了16.3%、4.0%、24.9%、29.5%；比二氧化氯高了4.4%、6.2%、6.3%、7.1%。同时，三维荧光光谱分析发现，高铁酸钾预氧化-混凝对溶解性有机物中类蛋白物质组分的去除率最高。本研究能够为引汉济渭工程受水区自来水厂生产运行提供科学依据。     

预涂动态膜对超滤膜处理海水中有机物的影响

分别以硅藻土和粉末活性炭为涂膜材料,系统考察了预涂动态膜对海水溶解性有机物的去除效果及作用机理,以及对超滤膜通量的影响。试验结果表明,预涂动态膜能提高超滤膜对UV254和DOC的去除率,硅藻土对蛋白类有机物有强化去除作用,粉末活性炭对蛋白类和腐殖类有机物有较强的去除效果。与超滤膜相比,硅藻土预涂动态膜、粉末活性炭预涂动态膜的膜通量分别增加了21.6%、46.0%,反冲洗后膜通量恢复率分别为88.6%、87.2%。     

磁性树脂吸附—混凝工艺深度处理印染废水中试研究

新建一套基于磁性树脂吸附—混凝工艺的自动化中试设备,对A、B两厂的印染废水生化出水进行深度处理,COD去除率70%,SS去除率接近90%,色度去除率在80%左右。磁性树脂可去除中低分子质量有机物,与混凝去除有机物形成了互补。该工艺对印染废水生化出水中比例最高的疏水有机组分去除效果最好。该工艺对A、B两厂废水的可吸附有机卤素(AOX)去除率分别达89.41%、88.27%,出水的急性毒性由微毒性降至无毒性,慢性毒性满足美国USEPA标准要求。     

磁性离子交换树脂在饮用水预处理中的应用

磁性离子交换树脂(MIEX Resin)是水处理领域新开发的一种新型树脂,由于其在给水预处理中的良好效果,成为研究的热点。文章对MIEX Resin的基本工作原理、MIEX DOC工艺的组成和效果、MIEX DOC工艺与其它水处理工艺的联合应用情况作了简要综述。MIEXR树脂的珠粒粒径和磁性,是MIEXR树脂有别于传统树脂的最大特点,并且这两个特点使此种树脂在给水预处理中得以有效应用。MIEX DOC工艺对相对分子质量中等和小的有机物有较高的去除率,与混凝在去除有机物方面具有互补作用,磁性离子交换树脂能极大改善后续工艺的处理效果。     

强化混凝中不同分子质量有机物的变化特点

采用三氯化铁作为混凝剂，通过变化投加量和pH，考察各个分子质量区间的DOC和UV254的变化情况，了解强化混凝去除有机物的效果和机理。增加混凝剂的投加量能有效地促进各分子质量区间的UV254的去除，但对DOC的去除效果较差。三氯化铁对小分子质量的有机物具有很好的去除效果，总去除率的至少50％为去除小分子质量有机物所贡献。降低pH能有效地促进各分子质量区间的DOC和UV254的去除，去除有机物的最佳pH为5．5。在最佳的pH下，小分子质量的有机物得到了最大限度的去除。     

常规处理与深度处理工艺对南京长江原水中有机物去除效能比较

以长江南京段原水为研究对象,通过常规处理及深度处理工艺(强化过滤工艺和生物活性炭工艺)对长江南京段水源水中有机物的去除效能进行对比研究。结果表明常规工艺对CODMn、UV254、DOC及BDOC的去除率分别为30%、41%、27%及25%。强化常规工艺和生物活性炭工艺各指标的去除率分别为34%和52%、48%和50%、37%和40%及74%和82%。强化过滤工艺及生物活性炭工艺对1,2,4-三氯苯的去除效果明显,能显著提高出水水质。常规工艺对MW大于5 kDa的有机物去除效果明显,强化过滤工艺对MW小于1 kDa的有机物去除率大于25%,生物活性炭工艺对各个分子量区间的去除效果都比较好,特别是对原水中占多数的MW小于1 kDa的有机物去除率大于30%。     

镇江市饮用水有机物分子量分布特性的研究

研究分析了镇江市原水、净水工艺和管网水中有机物分子量分布的变化特性.试验结果表明：原水水质较好,溶解性有机物含量维持在1.4～2.8mg/L之间,小分子有机物占溶解性有机物的主要部分;与常规处理相比,臭氧活性炭深度处理能有效提高DOC和UV254的去除效果;各个处理流程对大于1000分子量区间的有机物去除效果较好;氯和臭氧氧化能使有机物由高分子量区间向低分子量区间推移.     

生物活性炭工艺去除长江原水中有机成分的研究

以长江南京段原水为研究对象,以提高水处理出水水质和生物稳定性为目标,研究了生物活性炭工艺对有机物指标和氯苯类化合物的去除效果,并从有机物分子量的角度研究了生物活性炭工艺对有机物的去除机制。中试试验结果表明：生物活性炭工艺能有效地去除水中的有机物,对CODMn,UV254,溶解性有机碳（DOC）及可生物降解溶解性有机碳（BDOC）的去除率可分别达到52％,50％,40％和82％,对氯苯类化合物的去除效果也较为明显,去除率为40％左右。生物活性炭工艺对各个分子量区间的去除效果都比较好,对原水中占多数的小于1k的溶解性有机物（DOM）去除效果尤为显著。     

预臭氧 BAC工艺处理微污染原水参数优化与有机物去除特性

采用中试装置研究了预臭氧生物活性炭工艺对长江南京段微污染原水有机物的去除特性,考察了臭氧投加量和臭氧接触时间对预臭氧氧化、砂滤及生物活性炭单元中DOC、BDOC、CODMn、UV254和微量有机污染物去除的影响。结果表明当臭氧投加量为3 mg/L、臭氧接触时间为10 min时,预臭氧氧化单元中DOC、CODMn和UV254的去除率分别达到19％、31％和78％,BDOC增长了33％;砂滤单元四种指标的去除率分别为25％、52％、42％和44％,而生物活性炭滤柱对四种污染物指标的去除率分别为46％、83％、52％和20％,高于常规处理工艺。整个工艺对三种微量有机物（1,2,4三氯苯、DMP和DEHP）的去除率也分别达到了60％、68．6％和68．8％。与未投加臭氧相比,臭氧的投加有效促进了砂滤和生物活性炭对有机污染物的去除。采用预臭氧生物活性炭工艺处理微污染长江原水,有效提高了有机污染物的去除效果,可保障出水水质安全。     

两工艺流程对高藻原水中微量有机物的去除特性

试验以高藻水源水为处理对象,就两工艺流程(溶气气浮 活性炭过滤,溶气气浮 砂滤 活性炭过滤)对高藻原水中微量有机物的去除特性进行了考察。试验采用了强化混凝,气浮单元对有机物有一定去除效果,对DOC的去除率高于其它处理单元,而对于BDOC、AOC、HAAsFP,气浮单元的去除效果均弱于两流程的炭滤柱。流程2砂滤柱对有机物去除效果较差。对于试验考察的微量有机物,流程1的去除效果优于流程2,并且起主导作用的处理单元均为炭滤柱,而流程1炭滤柱的去除效果优于流程2炭滤柱。     

Improvement in the coagulation performance by combining Al and Fe coagulants in water purification

This study evaluated the beneficial effects on the coagulation process of combining coagulants with Fe and Al in the removal of turbidity and DOC (dissolved organic carbon), and proposed conditions for proper operation of a coagulation process. In addition, the floc characteristics and sludge dewater ability were evaluated. Blended coagulants were more effective than single coagulants at lower concentrations in water purification. The optimal blended ratio for the removal of DOC was 1.45 mM as Al/mM as Fe. Also, blended coagulants were less affected than single coagulants by pH, temperature, and rapid mixing intensity. Based on the results of the change in the apparent molecular weight distribution (AMWD) of DOC in raw and treated water by coagulation, low molecular weight organic matters were removed by 40.7% for the blended coagulant (1.45 mM as Al/mM as Fe). Blended coagulants formed larger flocs than single coagulants did. At pH 6.0, floc strength and sludge dewaterablity were both improved.     

The removal of natural organic matter from selected Turkish source waters using magnetic ion exchange resin (MIEX®)

The primary objective of this work was to evaluate the effectiveness of the MIEX^® process in removing natural organic matter (NOM) from selected drinking water sources of the City of Istanbul. Raw water samples from five drinking water treatment plants (Elmalı, B.Çekmece, Ömerli, İkitelli, and Kağıthane) serving to about 10 million people were collected and jar-tested in laboratory. The kinetics of NOM removal at various MIEX^® dose and contact times, the extent of resin saturation in multiple-loading experiments, and the impacts of MIEX^® pretreatment prior to coagulation on coagulant demands were investigated. After a resin dose of 5–10 ml settled resin/l and contact time of 10–20 min, dissolved organic carbon (DOC) concentrations and specific UV absorbance (SUVA₂₅₄) values obtained for all waters were <1.5 mg/l and <2 l/mg DOC-m, respectively. In addition, for all waters, 17–42% nitrate and 9–24% sulfate removals were obtained at a resin dose and contact time of 10 ml settled resin/l and 10 min, respectively. UV₂₅₄ absorbance reductions up to 96% were achieved. Increasing MIEX^® dose generally decreased the SUVA₂₅₄ values indicating that the MIEX^® resin preferentially removed UV absorbing fractions of NOM. Although some degree of initial resin saturation occurred in two raw waters up to 900 bed volume (BV) loadings, such saturations were not continuous up to 2000 BV loadings. The initial saturation was not observed for the other three waters, suggesting that MIEX^® resin can be loaded up to 2000 BVs or more (not tested) without any saturation. Depending on the raw water, the application of MIEX^® as a pretreatment prior to coagulation reduced the coagulant (alum) demand by 0–30 mg/l compared to the coagulation only. Results from the laboratory experiments overall indicated that MIEX^® resin even at relatively low dose and short contact time effectively removes NOM in all tested raw waters and reduces coagulant demands.     

Natural organic matter and formation of trihalomethanes in two water treatment processes

The investigation involved the study of performance of two local plants' slightly different treatment processes for the removal of natural organic matter (NOM) which comprises trihalomethane (THM) precursors. Ultrafiltration separated the contained NOM into various apparent molecular weight (AMW) fractions to reveal the two processes NOM removal efficiencies, in terms of dissolved organic carbon (DOC), UV absorbance (UV254) and THM formation potential (THMFP). DOC and UV254 levels of source water at both plants tested low and they concentrated in the portion with AMW less than 3,000 Daltons. The combined expression of UV254 with DOC as specific ultraviolet light absorbance (SUVA) indicated that the source water of Macau had a value less than 3 L/mg-m. Therefore the main DOC content was fulvic in character, which is difficult to remove and favors the formation of brominated THMs. Low DOC removal percentages recorded in both processes confirm this observation. However, both processes showed similar removal efficiency of around 50% on humic substances and THM precursors quantified by measurements of UV254 and THMFP, respectively.