几种自来水中消毒副产物的光催化处理研究

随着饮用水水源污染的加重和现代分析技术的发展,越来越多的卤代消毒副产物,如二氯甲烷、卤乙腈等频频在饮用水中被检出。本文通过设计并自制一款光催化净水装置,以多孔泡沫陶瓷为载体负载光催化剂二氧化钛薄膜,利用多相光催化技术对饮用水中的消毒副产物进行去除研究。通过试制光催化净水装置,调节不同流量、不同光照条件、催化剂及载体孔径等条件对消毒副产物的去除率进行对比,得到该净水装置的优化运行条件。实验结果表明,无论二氯甲烷还是一溴二氯甲烷的光催化去除效率最高的流量均为120 L/h。利用该装置对消毒副产物的降解,光照强度越大,降解效率越高。消毒副产物的降解还与二氧化钛光催化剂的载体有关,使用孔径为20ppi的泡沫陶瓷做载体效果高于使用10 ppi和30 ppi的泡沫陶瓷做载体。总有机碳(TOC)测试结果表明,饮用水中的消毒副产物在很大程度上能被光催化反应装置所矿化分解。     

生物性污染废水的电化学消毒试验研究

研究了电化学消毒应用于生物性污染废水的效果,探讨了氯离子浓度、电流密度、pH以及浊度对杀菌效果的影响.结果表明,氯离子浓度是电化学消毒的主要影响因素,原水氯离子浓度从50 mg·L-1提高到450mg·L-1时,5 min的杀菌率从48.78%提高到92.86%,而30 min可达到99.99%.电流密度的增加能够提高杀菌效果,但是过高的电流密度会降低电流效率.酸性pH条件下的杀菌效果要优于中性和碱性条件.混凝预处理不仅能够预先去除水中大部分细菌,降低水的浊度,同时也能提高后续电化学杀菌效果.     

强化混凝在给水处理工程中的应用

强化混凝技术目前在给水领域主要应用于控制饮用水中消毒副产物的含量,以求达到更高的饮用水水质要求。依据国内外进行过的试验研究及应用,综述了强化混凝技术的研究进展及结果,在此基础上探讨了强化混凝在给水处理工程特别是石化企业净水系统中的应用前景。     

二氧化氯稳定性的研究

二氧化氯在氧化、杀菌、消毒等方面具有氯气、臭氧无法比拟的优势。它可以在水中较长时间维持一定浓度,抑制水中病菌生长,达到净水目的。本文对二氧化氯的稳定性进行研究,提出了数学模型。     

对饮用水中剩余铝问题的研究和探讨

本文论述了饮用水中剩余铝浓度的增加对人体和净水工艺可能造成的危害，列举了国内外饮用水中铝含量的标准及它们的变化趋势，分析了各种因素对剩余铝含量的影响，研究了文献中有关降低饮用水中剩余铝的方法。     

EGCG-Cu对水中大肠杆菌的杀灭性能研究

采用水热法由EGCG和硫酸铜溶液制备EGCG-Cu络合物,研究其对水中大肠杆菌的杀灭性能。结果表明,EGCG-Cu的杀菌性能优于EGCG,为达到相同的杀菌效果,EGCG-Cu的投加量远低于EGCG;EGCG-Cu杀菌性能随浓度增加而增强,EGCG-Cu投加浓度50 mg/L时,大肠杆菌的生长受到严重抑制,对数生长阶段几乎消失;EGCG-Cu浓度越高,接触时间越长,各时刻大肠杆菌溶液中蛋白质的含量越高;EGCG和EGCG-Cu不会影响大肠杆菌基因组的降解,EGCG-Cu消毒机理主要体现在对大肠杆菌细胞膜的破坏,而不是直接作用在其基因组。     

超滤膜技术组合工艺对饮用水氯消毒的生物稳定性试验

以某水库微污染水源水为试验水样,比较了以超滤为核心的不同组合工艺的净水效果,考察了各组合工艺出水氯消毒对异养菌的灭活效果、持续消毒能力,研究了余氯的衰减、消毒副产物的生成以及对水质生物稳定的影响,从生物安全性和化学安全性两个方面对不同超滤组合工艺出水氯消毒安全性进行综合评价。结果表明,混凝沉淀-粉末活性炭-超滤组合工艺具有最佳的净水效果:该工艺能100%的去除水中的细菌总数、大肠杆菌;持续消毒能力强,72 h后水中余氯量为0.5 mg/L,对细菌总数、大肠杆菌的去除率仍为100%,且HPC小于100 CFU/mL,符合生活饮用水卫生标准;消毒副产物的生成量控制在10μg/L以下;出水AOC含量低于100μgac-C/L,符合氯化消毒生物稳定性的要求。     

三碘树脂的制备及其净水作用

本文主要介绍了三碘树脂的制备方法，杀菌机理及其净水作用，并对水的ｐＨ值，温度，水中阴离子浓度及接触时间对三碘树脂稳定性和灭菌效果的影响进行了探讨。     

新型生活用水净化设备的设计

在传统的饮水设备的基础上,设计出一种新型家庭用水净化设备,具有较高的应用推广价值.该设备采用臭氧消毒、超滤、紫外线杀菌相结合的净水方式,可把生活用水净化成用于洗涤的臭氧水和饮用的纯净水,作者分析了该设备关键部件的设计计算要点.     

饮用水中消毒副产物的形成机理与控制技术研究

饮用水中消毒副产物主要存在形式为三卤甲烷类和卤乙酸类有机物。对饮用水中消毒副产物的形成机理及目前控制饮用水中消毒副产物的方法和特点进行了论述     

Legionella inactivation with diamond electrodes

The DiaCell® technology has been successfully tested against Legionella infection in several water types and under various working conditions. Depending on the water composition, Legionella can be completely inactivated with current densities as small as 50 mA/cm² with low contact times (<5 min). The higher the oxidant concentration in the electrolyzed water, the more rapid is the Legionella inactivation after injection. Bicarbonates in contaminated water were identified as very good supports for electrochemical disinfectants production for Legionella inactivation without high chlorine concentration. At the same time, sulfates in water do not provide any disinfection capacity by DiaCell® electrolysis.     

复合二氧化氯的制备及其用于城市污水回用消毒

在酸性环境中通过NaCl电解协同NaClO2化学氧化方法制备的复合二氧化氯溶液中ClO2和自由氯浓度分别达到70%和20%左右,系统地研究了电流密度(A)、NaClO2与NaCl质量比(B)、电解时间(C)对复合溶液中组分浓度和质量百分数的影响,并将复合溶液用于城市污水二级处理出水的消毒。结果表明,复合溶液中自由氯的浓度主要受因素C和A的影响,ClO2的浓度主要受因素C和B的影响,而A对副产物ClO2-和ClO3-的影响最大。总大肠菌群数在105~108个.L-1的城市污水二级处理出水采用复合溶液消毒时,当其中ClO2投加量为4 mg/.L-1,自由氯含量不低于1.20mg.L-1,经30min接触后出水生物学指标满足GB/ T18920-2002 的要求。既降低了消毒剂的使用量,又减少了消毒副产物ClO2-的生成。     

油田废水电解杀菌研究

采用电解杀菌技术处理油田废水，研究了电解时间、电流强度、极板间距以及电极联结方式等因素对废水中硫酸盐还原菌杀灭效果的影响。结果表明，油田废水经3min电解杀菌，硫酸盐还原菌杀灭率高达99．90％。随着电解时间的增加，硫酸盐还原菌的杀菌率进一步提高；电流强度增加，硫酸盐还原菌的杀灭率升高。在电流强度保持不变的情况下，随着极板间距增加，极板之间电压升高，更有利于杀灭硫酸盐还原菌。在极板间电流强度相同的条件下，两种电极联结方式的杀菌率差别不大，杀菌率均在99．9％以上。     

Hydrogen peroxide production by water electrolysis: Application to disinfection

Hydrogen peroxide was produced by direct current electrolysis using only two electrodes, a carbon felt cathode and a RuO₂ coated titanium anode. The required oxygen was supplied by oxidation of water and by transfer from the atmosphere or by pure oxygen injection. The current was maintained below a maximum value to avoid peroxide reduction. A high peroxide production rate was reached and a 15 mg l^–1 concentration was maintained. The electrolysis removed turbidity and dissolved organic carbonaceous compounds from municipal sewage plant effluents. Real effluents were significantly disinfected owing to the direct effect of electric current and the indirect effect of peroxide. A residual effect was also observed.     

液氯和次氯酸钠对饮用水消毒效果的生产性试验研究

以次氯酸钠代替液氯消毒是未来饮用水消毒的重要发展方向,但对于次氯酸钠消毒对供水水质的影响一直缺乏生产性试验研究.以上海2个净水厂实际生产工艺考察了液氯和次氯酸钠2种消毒剂的消毒效果,对于其在微生物消毒效果、消毒副产物生成和对氮磷及有机物去除方面进行了比较分析.研究发现,2种消毒方式对微生物的杀菌效率基本相同,但是次氯酸...     

多孔圆筒铸铁阳极电解制备高铁酸盐的研究

采用双阴极室隔膜电解槽，以多孔圆筒铸铁为阳极电解制备水处理剂高铁酸盐。实验表明，所用电解槽与平板铸铁阳极电解槽相比可得到更高的电流效率和更高浓度的高铁酸盐。在14mol／L的氢氧化钠溶液中加入0．1％（质量分数，下同）氯化钠，30℃下以30mA／cm^2的电流密度电解6h，电流效率高出36．2％，高铁酸根离子浓度达0．07mol／L。     

TiO2膜光电催化氧化法降解印染废水的研究

采用TiO2膜电极,利用电化学和光催化协同作用对印染废水进行了降解,讨论了协同作用的机理。考察了电流密度、溶液pH值和光照强度等因素对降解率的影响。研究结果表明：光电催化氧化法的活性蓝染料溶液降解率高于电极氧化法和光催化法,证明电化学和光催化在反应过程中具有协同作用。在电流密度20 mA/cm2、pH值为4、光照距离为8 cm的条件下,降解初始浓度100 mg/L活性蓝染料模拟印染废水,2.5 h时COD去除率为88.4%,色度脱除率为93%。     

紫外线和化合氯联合消毒在水厂的应用研究

以南方某水厂的中试和生产紫外消毒装置为基础,考察了紫外和化合氯联合消毒对生物活性炭出水细菌的杀灭效果,对紫外消毒在该水厂的应用效果进行了评价。研究表明,在480 J/m2的剂量下,生物活性炭出水细菌对数去除率可达2.6 lg,但是紫外无持续杀菌作用。水厂的紫外消毒装置总体效果良好,紫外化合氯消毒后出水细菌总数为0,紫外线消毒长时间运行后灭菌效率有所降低;生物活性炭工艺对氯胺消毒副产物有较好的控制效果,紫外消毒未增加氯消毒副产物的生成量。     

Inactivation of Escherichia coli in Na2SO4 electrolyte using boron-doped diamond anode

Electrochemical disinfection in chloride-free electrolyte has attracted more and more attention due to advantages of no production of disinfection byproducts (DBPs), and boron-doped diamond (BDD) anode with several unique properties has shown great potential in this field. In this study, inactivation of Escherichia coli (E. coli) was investigated in Na₂SO₄ electrolyte using BDD anode. Firstly, disinfection tests were carried on at different current density. The inactivation rate of E. coli and also the concentration of hydroxyl radical (OH) increased with the current density, which indicated the major role of OH in the disinfection process. At 20 mA cm⁻² the energy consumption was the lowest to reach an equal inactivation. Moreover, it was found that inactivation rate of E. coli rose with the increasing Na₂SO₄ concentration and they were inactivated more faster in Na₂SO₄ than in NaH₂PO₄ or NaNO₃ electrolyte even in the presence of OH scavenger, which could be attributed to the oxidants produced in the electrolysis of SO₄²⁻, such as peroxodisulfate (S₂O₈²⁻). And the role of S₂O₈²⁻ was proved in the disinfection experiments. These results demonstrated that, besides hydroxyl radical and its consecutive products, oxidants produced in SO₄²⁻ electrolysis at BDD anode played a role in electrochemical disinfection in Na₂SO₄ electrolyte.     

The occurrence of bromate and perbromate on BDD anodes during electrolysis of aqueous systems containing bromide: first systematic experimental studies

Bromide electrolysis was carried out on laboratory-scale cells in the range of 1–1,005 mg [Br⁻] dm⁻³ using boron-doped diamond (BDD) anodes. These studies were part of fundamental research activities on drinking water electrolysis for disinfection. Synthetic water systems were mostly used in the experiments, which varied the temperature between 5 and 30 °C, the current density between 50 and 700 A m⁻², and the rotation rate of the rotating anode between 100 and 500 rpm (laminar regime). Hypobromite and bromate were found as by-products, as expected. Bromite was not detected. Higher bromate levels were formed at higher current density, but no clear relationship was observed between bromate concentration and the rotation rate or temperatures between 5 and 30 °C. Bromate yields higher than 90% were found at higher charge passed. Perbromate was found as a new potential synthesis or disinfection by-product (DBP), but no perbromate was detected at the lowest bromide concentrations and under drinking water conditions. The perbromate yield was about 1%, and somewhat lower when bromate was used as a starting material instead of bromide. At a temperature of 5 °C more perbromate was detected compared with experiments at 20°. Approximately 20 times more perchlorate was formed compared with perbromate formation in the presence of chloride ions of equimolar concentration. State of mechanistic considerations is presented and a mechanism for perbromate formation is proposed. The reaction from bromate to perbromate was found to be limited that is in contrast to the earlier studied chlorate-to-perchlorate conversion. In the measured concentration range, reduction processes at the mixed oxide cathode showed a much higher impact on the resulting concentration for perbromate than for bromate.