北方水库水中有机物化学分级及THMFP特征研究

采用树脂吸附法对我国东北地区3种水库水中的有机物进行了化学分级表征及三卤甲烷生成势的研究.结果表明,3种水库水中的溶解性有机物主要是亲水性有机酸(HPIA)和疏水中性物质(HPON),在有机物组分分布上具有一致性;HPON的THMFP值最高,而且占总DOC的百分比也很大,说明HPON是主要的三卤甲烷前体物;虽然各水库水中三卤甲烷生成活性最高的组分不相同,但疏水性有机物的三卤甲烷生成活性均高于亲水性有机物的;从3种水库水的有机物组分特征可知,虽然各水库水的水质有一定差异,但它们的三卤甲烷前体物特征具有一致性.     

气浮和沉淀工艺对三卤甲烷生成势的去除特性研究

研究了气浮和沉淀工艺对不同分子质量区间三卤甲烷生成势(THMFP)的去除效果及絮体形态对去除THMFP的影响。结果表明,气浮工艺对各分子质量区间THMFP的去除效果均优于沉淀工艺,二者均以去除大分子质量区间的THMFP为主,对小分子质量区间THMFP的去除效果较差。UV254与THMFP值的线性相关系数为0.917,UV254值可以较好地反映THMFP的含量。气浮絮体的分形维数小于沉淀絮体,孔隙率较大,可以增加对有机物的活性吸附空间;气浮絮体尺寸较小,具有更好的同向絮凝效果,增加了絮体和有机物的接触概率,从而使气浮工艺对THMFP的去除效果优于沉淀工艺。     

藻细胞及胞外分泌物对三卤甲烷生成势的影响

以处于对数生长期后期的悦目颤藻为研究对象,研究藻细胞及其胞外分泌物(EOM)对三卤甲烷生成势(THMFP)的贡献,以及臭氧预氧化中臭氧投量及预氧化时间对THMFP的影响.研究表明EOM是原水中主要的THM前体物;藻细胞和EOM形成的三卤甲烷主要是三氯甲烷和一溴二氯甲烷.对含藻细胞水样的臭氧预氧化研究表明随着臭氧投量的增加,含藻细胞水样的三氯甲烷生成势和THMFP持续增加;随着预氧化时间的延长,THMFP几乎呈线性增加;臭氧预氧化会破坏藻细胞,使得胞内物质释放出来,这部分物质中的一部分是THM的前体物.对含EOM水样的臭氧预氧化研究表明随着臭氧投量的增加和预氧化时间的延长,臭氧氧化EOM使其不饱和键减少,生成的总卤代产物浓度减小;低投量的臭氧预氧化可以强化混凝去除EOM中的THM前体物,在试验条件下0.486 mg/L的臭氧作用5 min可强化混凝去除EOM中THMFP,去除率比单纯混凝高9.8%;随着预氧化时间的延长,含EOM水沉后水三氯甲烷生成势和THMFP略有升高,说明延长预氧化时间会引起含EOM水沉后水三卤甲烷前体物浓度的增加.由此,低投量短时间的臭氧预氧化可以强化混凝去除EOM的THMFP;并且在实际水处理中,应该在去除藻细胞之后再进行臭氧氧化处理,这样可防止臭氧氧化使藻细胞内物质释放而增加THM前体物浓度.     

混凝/微滤去除滦河水中不同分子质量有机物的效果

采用混凝/微滤工艺处理滦河水,以DOC、UV254、THMFP为指标考察了处理前、后水中有机物的分子质量分布.结果表明,原水中的有机物以溶解性小分子有机物为主,该部分有机物是生成THMs的主要物质,其中分子质量为1-3 ku的有机物生成THMs的能力最强;混凝/微滤工艺对分子质量>10 ku的DOC的去除效果较好,在各个分子质量区间,对UV254的去除率均高于对DOC的;系统对THMFP的去除率约为40%.     

TiO_2/UV光催化氧化耦合膜分离处理太湖水的效果

在连续运行模式下考察了淹没式平板膜光催化反应器(FSMPR)对太湖水中有机物的去除效果,及其对膜污染的缓解效果。结果表明,TiO_2/UV光催化氧化预处理太湖水不仅可以提高对有机物的去除效果,降低三卤甲烷生成势(THMFPs),同时也可减轻膜污染,降低膜操作压力。即使在30 L/(m~2·h)以上的高通量下运行,FSMPR动态操作过程中也没有发生明显的膜污染。跨膜压差(TMP)检测结果表明,原水中的部分疏水有机物是造成膜污染的主要物质,而原水中的以及降解过程中生成的亲水性小分子有机物,不会对膜造成明显的污染。     

南方某河流原水中消毒副产物前体物的季节性变化

对我国南方某河流原水进行了一个水文年的监测,通过树脂吸附法等手段对水样中的有机物进行分离富集,分析了藻类及颗粒性有机物、溶解性有机物中不同极性组分对消毒副产物(DBPs)的贡献,同时分析其季节性变化规律。研究发现,原水中DBPs的生成势与有机物含量的变化基本一致,三卤甲烷、卤乙酸和三氯乙醛等3类DBPs前体物含量均在夏季最高;藻类及颗粒性有机物对DBPs的贡献率为6.07%~30.69%,且对三氯乙醛的贡献率要大于对三卤甲烷和卤乙酸的贡献率;原水中的溶解性有机物在春夏季以亲水性有机物为主,而在秋冬季则以强疏水性有机物为主,并且成为主要的DBPs前体物。     

磁性离子交换树脂与超滤膜联用处理淮河原水

采用磁性离子交换树脂(MIEX)/混凝沉淀/超滤膜(UF)工艺处理淮河原水,考察了对有机物的去除特性以及MIEX预处理控制膜污染的效果.结果表明:UF出水浊度稳定在0.1NTU以下,粒径>2 μm的颗粒数平均为11个/mL,粒径>10μm的颗粒物被完全去除;组合工艺对CODMn和UV254的去除率分别为75.3%和90%,且能有效去除不同分子质量区间的有机物;系统对疏水性有机物(HOM)、弱疏水性有机物(WHOM)、荷电亲水有机物(HIC)的去除效果均较好,去除率分别为94.6%、82.7%和81.3%;组合工艺对三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)的去除率分别为90.7%和87.6%;MIEX预处理可有效减缓膜污染,运行期间超滤膜的跨膜压差上升缓慢,经水力反冲洗后跨膜压差就基本得到恢复.     

城市饮用水水源水质的变化特性分析

从季节性差异分析了我国东北某城市两座水源地水库的浊度、CODMn氨氮、UV254三卤甲烷生成潜能(THMFP)、叶绿素a的变化规律.结果表明,B水库原水水质要好于A水库,两座水库原水浊度、有机物和三卤甲烷前驱物含量均呈季节性变化;A水库CODMn最高值为6.5 mg/L,最低值为2.8 mg/L;B水库CODMn最高值为5.0 mg/L,全年的最低值0.5 mg/L出现在3月;B水库叶绿素a在春夏之交变化较明显,A水库和B水库六个月内叶绿素a的平均值分别为36.53和22.25 mg/m3,UV254平均值分别为0.11和0.112 cm-1.     

不同滤料去除、控制三卤甲烷效果的生产性试验研究

在水厂生产性试验的规模,对比研究了不同原水水质条件下,石英砂、活性炭、活性无烟煤这三种不同滤料过滤对TOC、UV254的去除率,以及控制三卤甲烷生成的效果。结果表明,活性炭、活性无烟煤过滤能在混凝-沉淀的基础上进一步降低TOC、UV254,并减小三卤甲烷生成潜能,而石英砂过滤对TOC、UV254基本无去除,对控制THMFP无明显效果。     

预氯胺化控制消毒副产物技术研究

把氯胺作为一种预氧化剂,研究了预氯胺化工艺中消毒副产物的生成及变化规律.经研究发现,原水中含有一定浓度的氨氮可以有效地降低总三卤甲烷(TTHMs)的生成.TTHMs随着氯胺量的增加而略有增加;预氯胺化反应48 h后TTHMs不再明显增加;随着pH值的升高,TTHMs(主要是溴代三卤甲烷)明显减少;随着氯氮比的增加,溴代三卤甲烷生成量明显升高,经分析认为可能是pH值和氯氮比对溴离子(Br-)与氯胺的卤代反应影响较为复杂造成的.     

从DOC、AOC的变化分析二氧化氯消毒工艺

考察了二氧化氯（CIO2）及其组合消毒工艺中溶解性有机物（DOC）浓度和可同化有机碳（AOC）浓度的变化规律。结果表明,以DOC表征的有机物浓度在消毒反应前后变化不大;CIO2的强氧化能力体现在将高分子有机物氧化成中、小分子有机物方面,氧化产物以草酸类物质为主,这导致了AOC浓度的升高,降低了出水的生物稳定性;增加CIO2的投量（〉4mg／L）或与氯胺组合消毒能有效降低出水的AOC浓度,消毒反应24h后出水的AOC浓度均比进水的（59μg/L）低。     

Mode d'action du bioxyde de chlore sur les composes organiques en milieu aqueux Consommations de bioxyde de chlore et reactions sur les composes phenoliquesMode of action of chlorine dioxide on organic compounds in an aqueous medium en|Chlorine dioxide consumption and reactions on phenolic compounds

The aim of our work was to study the reaction between chlorine dioxide (ClO₂) and organic substances. In the first part of our survey, chlorine dioxide demands were measured in diluted aqueous solutions of various kinds of organic compounds (5 × 10⁻⁵ −10 M) at pH 7. In the second part, the study of the action of chlorine dioxide on phenols (phenol, di and triphenols) was undertaken by observing the change of the organic substance through global parameter controls (COT, u.v. spectrum) and by trying to identify a certain number of oxidation products by means of chromatographic analysis (HPLC and GC), of mass spectrometry and of Nuclear Magnetic Resonance spectrometry (NMR).     

Effect of oxidants on microalgal flocculation

The effects of chlorine, ozone and chlorine dioxide on Scenedesmus sp. cultures were studied. Algal cell viability and chlorophyll concentration decreased, and the concentration of dissolved organic substances increased with increasing applied oxidant concentration. Pretreatment with chlorine dioxide (1, 3 or 5 mg l⁻¹) or ozone (2.6, 4.6 or 8.1 mg l⁻¹) on algal cultures enhanced algal flocculation with alum, while prechlorination with 10 or 20 mg l⁻¹ increased the required dosage of alum by 15%. Scanning electron micrographs of oxidized cells revealed drastically adverse effects upon the cell surface architecture: in addition to the oxidation of noncellular organic materials, the oxidants damaged both cell surface structures and intracellular components. A model explaining the effects of the different oxidants on microalgal flocculation is suggested.     

二氧化氯、氯胺顺序投加联合消毒工艺的研究

以天津市某自来水厂的滤后水为研究对象,采用二氧化氯、氯胺顺序投加联合消毒工艺对其进行消毒处理。运用化学分析和生物学试验的方法,考察了经不同投量的组合消毒后消毒剂残余量的变化,以及联合工艺的消毒效果和持续消毒能力。试验结果表明,经不同投量组合的二氧化氯、氯胺顺序投加联合消毒后,出水中的细菌总数及总大肠菌群均达到《生活饮用水卫生标准》的要求。氯胺投量对总余氯和二氧化氯残余量的影响显著,而二氧化氯的投加量对其残余量的影响不大。二氧化氯、氯胺顺序投加联合消毒工艺在低投量组合下就能达到良好的消毒效果,且持续消毒能力强。     

Mode d'action du bioxyde de chlore sur les composes organiques en milieu aqueux: Consommations de bioxyde de chlore et reactions sur les composes phenoliques

The aim of our work was to study the reaction between chlorine dioxide (ClO₂) and organic substances. In the first part of our survey, chlorine dioxide demands were measured in diluted aqueous solutions of various kinds of organic compounds (5 × 10⁻⁵ −10 M) at pH 7. In the second part, the study of the action of chlorine dioxide on phenols (phenol, di and triphenols) was undertaken by observing the change of the organic substance through global parameter controls (COT, u.v. spectrum) and by trying to identify a certain number of oxidation products by means of chromatographic analysis (HPLC and GC), of mass spectrometry and of Nuclear Magnetic Resonance spectrometry (NMR).     

纯培养条件下细菌需氯量和存活性的试验研究

以埃希氏大肠杆菌和粪肠球菌作为研究对象,在纯培养条件下考察了自由氯、氯胺和二氧化氯的投加量以及细菌初始浓度对需氯量的影响.结果表明:灭活率达到99.9％时,两种细菌的需氯量均随初始菌浓度和消毒剂投加量的提高而增大,粪肠球菌的需氯量大于埃希氏大肠杆菌;投加自由氯时两种细菌的需氯量差别最大,其次是二氧化氯,氯胺的差别最小.     

Sequential inactivation of Cryptosporidium parvum oocysts with chlorine dioxide followed by free chlorine or monochloramine.

The main objective of this study was to assess the effect of temperature (4-30 degrees C) on the inactivation kinetics of Cryptosporidium parvum oocysts with sequential disinfection schemes involving the use of chlorine dioxide as the primary disinfectant and free or combined chlorine as the secondary disinfectant in synthetic water. The synergy previously reported for sequential inactivation of C. parvum oocysts with ozone/free chlorine or ozone/combined chlorine did not occur when chlorine dioxide was used. instead of ozone, as the primary disinfectant within the temperature range (4-30 degrees C) and the pre-treatment levels investigated. Sequential ozone/chlorine dioxide and chlorine dioxide ozone experiments revealed that the lower level or absence of synergy for chlorine dioxide/free chlorine and chlorine dioxide, monochloramine was likely the result of chlorine dioxide reacting with oocyst chemical groups that are mostly different from those reacting with ozone, free chlorine, or monochloramine. The CT concept was found to be valid for the primary inactivation kinetics of C. parvum oocysts with chlorine dioxide, thus allowing the use of the simpler CT approach for the development of C. partum inactivation requirements with chlorine dioxide. General consistency was found between the secondary inactivation kinetics of C. parvum oocysts with free chlorine and monochloramine after chlorine dioxide pretreatment obtained in this study with oocyst viability determined by a modified in vitro excystation method and those reported in the literature for the same sequential disinfection schemes based on an animal infectivity assay.     

强化消毒法对水中粪肠球菌灭活效果研究

在实验室条件下,研究了自由氯、氯胺和二氧化氯在不同剂量下对水中粪肠球菌的灭活效果.结果表明,自由氯、氯胺和二氧化氯对水中粪肠球菌具有较好的灭活效果,当消毒剂投加量为1 ～4 mg/L,接触时间为30 min时,粪肠球菌的灭活率基本在99％以上;自由氯的消毒反应速率最快,其次是二氧化氯,氯胺的反应速率最慢.     

Mechanisms of inactivation of hepatitis A virus in water by chlorine dioxide

In this study, to elucidate the mechanisms of inactivation of hepatitis A virus (HAV) by chlorine dioxide, cell culture, enzyme-linked immunosorbent assay (ELISA), and long-overlapping RT-PCR were used to detect the infectivity, antigenicity, and entire genome of HAV before and after disinfection. The results revealed the complete inactivation of infectivity after a 10-min exposure to 7.5mg of chlorine dioxide per liter; and the highest level of sensitivity in the 5'non-translated regions (5'NTR) (the sequence from bp 1 to 671), inactivation of which took as much time as the inactivation of infectivity of HAV by chlorine dioxide; the complete destruction of antigenicity after a 10-min exposure to 7.5mg of chlorine dioxide per liter. It is suggested that the inactivation mechanism of HAV by chlorine dioxide was due to the loss of the 5'NTR and/or destruction of the antigenicity, which is not similar to that of chlorine (Appl Environ Microbiol 68: 4951).