生物一体化反应器处理医院污水

采用一体化生物反应器-消毒工艺处理大庆地区某医院污水,处理效果良好且工艺运行稳定。介绍了工艺流程、主要设备及工艺的调试及运行。运行结果表明:出水COD、氨氮、SS分别低于50,10,15 mg/L,均满足设计要求,地埋式一体化生物反应器适合高寒地区医院等行业污水处理。     

Electrochemical disinfection using the gas diffusion electrode system

A study on the electrochemical disinfection with H_2O_2 generated at the gas diffusion electrode (GDE) from active carbon/poly-tetrafluorcethylene was performed in a non-membrane cell. The effects of Pt load and the pore-forming agent content in GDE, and operating conditions were investigated. The experimental results showed that nearly all bacterial cultures inoculated in the secondary effluent from wastewater treatment plant could be inactivated within 30 min at a current density of 10 mA/cm~2. The disinfection improved with increasing Pt load. Addition of the pore-forming agent NH_4HCO_3 improved the disinfection, while a drop in the pH value resulted in a rapid rise of germicidal efficacy and the disinfection time was shortened with increasing oxygen flow rate. Adsorption was proved to be ineffective in destroying bacteria, while germicidal efficacy increased with current density. The acceleration rate was different, it initially increased with current density. Then decreased, and finally reached a maximum at a current density of 6.7 mA/cm~2. The disinfection also improved with decreasing total bacterial count. The germicidal efficacy in the cathode compartment was approximately the same as in the anode compartment, indicating that the contribution of direct oxidation and the indirect treatment of bacterial cultures by hydroxyl radical was similar to the oxidative indirect effect of the generated H_2O_2.     

Formation potentials of typical disinfection byproducts and changes of genotoxicity for chlorinated tertiary effluent pretreated by ozone

The effects of ozonation on the formation potential of typical disinfection byproducts (DBPs) and the changes of genotoxicity during post chlorination of tertiary effluent from a sewage treatment plant were investigated. Ozonation enhanced the yields of all detected chlorine DBPs except CHCl3. At a chlorine dose of 5 mg/L, the three brominated THMs and five HAAs increased, while chloroform decreased with the increase of ozone dose from 0 to 10 mg/L (ozone dose in consumption base). At a chlorine dose of 10 ...     

Formation potentials of typical DBPs and changes of genotoxicity for chlorinated tertiary effluent pretreated by ozone

The effects of ozonation on the formation potential of typical disinfection byproducts (DBPs) and the changes of genotoxicity during post chlorination of tertiary effluent from a sewage treatment plant were investigated. Ozonation enhanced the yields of all detected chlorine DBPs except CHCl3. At a chlorine dose of 5 mg/L, the three brominated THMs and five HAAs increased, while chloroform decreased with the increase of ozone dose from 0 to 10 mg/L (ozone dose in consumption base). At a chlorine dose of 10 mg/L, the two mixed bromochloro species THMs and two dominant HAAs (DCAA and TCAA) firstly increased and then decreased with the increase of ozone dose, with the turning point approximately occurring at an ozone dose of 5 mg/L. The genotoxicity detected using umu test, on the other hand, was removed from 7 μg 4-NQO/L to a negligible level by ozonation under an ozone dose of 5 mg/L. Chlorination could further remove the genotoxicity to some extent. It was found that SUVA (UV absorbance divided by DOC concentration) might be used as an indicative parameter for monitoring the removal of genotoxicity during the oxidation.     

H2O2-固载型TiO2光催化对城市污水消毒作用研究

以泡沫镍作为载体,利用电沉积技术将纳米TiO2负载在泡沫镍上,制成固载型TiO2光催化反应器,在光催化反应器中加入H2O2,研究H2O2-固载型TiO2光催化反应系统对城市污水消毒效果。试验表明,固载型TiO2光催化反应中加入10 ppm H2O2,能大大提高紫外消毒效果,降低原水浊度对紫外消毒系统的影响,同时显著减少紫外消毒系统出水光复活现象。H2O2-固载型TiO2光催化反应系统,对降低紫外消毒投资和运行成本,提高紫外消毒效果稳定性,促进城市污水紫外消毒技术的推广具有重要意义。     

Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

The e ects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOCl) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.     

浙江省H市供水系统消毒副产物及其健康风险评价

以浙江省H市供水系统为调查对象,采用配有电子捕获器的气相色谱(GC-ECD)检测2座水厂及相应供水管网中18种消毒副产物(DBPs)的含量,深入探讨了DBPs导致的饮用水健康风险及前体物指标与各类DBPs的相关性.结果发现H市饮用水中检出三卤甲烷(THMs)、卤乙酸(HAAs)、卤乙腈(HANs)和三氯硝基甲烷(HNMs)等类消毒副产物,THMs含量最高,HAAs次之.CX水厂出水和供水管网中THMs分别为7. 70～32. 73μg·L~(-1)和9. 00～51. 42μg·L~(-1),HAAs分别为3. 05～21. 30μg·L~(-1)和6. 00～26. 79μg·L~(-1). TH水厂出水和供水管网中THMs分别为8. 65～38. 76μg·L~(-1)和12. 09～42. 04μg·L~(-1),HAAs分别为2. 42～14. 79μg·L~(-1)和2. 80～33. 40μg·L~(-1),2家水厂出厂水和供水管网中消毒副产物浓度均符合《生活饮用水卫生标准》(GB 5749-2006).采用溶解性有机碳(DOC)和UV254表征水样有机物,分析有机物与DBPs的相关性,发现管网水中三氯甲烷(TCM)与DOC和UV254呈显著负相关性.基于EPA推荐的健康风险评价模型对经口摄取途径时氯消毒副产物的致癌和非致癌风险进行计算,发现H市出厂水和管网水中消毒副产物引起的致癌风险分别为5. 94×10-6～4. 76×10-5和5. 94×10-6～5. 56×10-5,非致癌风险分别为0. 91×10-2～4. 20×10-2和1. 26×10-2～4. 72×10-2.致癌风险主要来自THMs,一溴二氯甲烷(BDCM)贡献了最高的致癌风险,非致癌风险主要来自TCM.     

Influencing factors of disinfection byproducts formation during chloramination of Cyclops metabolite solutions

Effects of reaction time, chlorine dosage, pH and temperature on the formation of disinfection byproducts(DBPs), were investigated during the chloramination of Cyclops metabolite solutions. The results showed that some species of DBPs like trichloromethane(TCM), dichloroacetic acid(DCAA) and trichloroacetic acid(TCAA) could accumulate to their respective stable values with a progressive elevation in reaction time and monochloramine concentration. And 1,1,1-2-trichloropropanone(1,1,1-TCP) content decreased correspondingly with a continuous increase of reaction time. The amounts of chloral hydrate(CH), chloropicrin(TCNM), 1,1,1-TCP and DCAA firstly increased and then decreased with increasing monochloramine doses. Higher temperature resulted in a decrease of CH, dichloroacetonitrile(DCAN), 1,1-dichloropropanone(1,1-DCP), 1,1,1-TCP, DCAA and TCAA concentration. pH affected the formation of the different DBPs distinctly. TCM accumulateded with the increase of pH under 9, and DCAA, TCAA, CH and 1,1-DCP decreased continuously with increasing pH from 5 to 10, and other DBPs had the maximum concentrations at pH 6–7.     

紫外线消毒系统中强度分布的理论计算与生物验证对比

应用以MPSS模型为基础的计算软件UV calc对某饮用水紫外线消毒反应器进行强度分布的计算,同时,采用枯草芽孢杆菌(ATCC9372)作为受试菌种进行生物验证.结果显示,在该反应器中理论计算数值总体上明显高于生物验证的数值,反应器中最低紫外剂量区域出现在2支灯管之间的反应器壁附近.另外,理论计算和生物验证的误差与流量、透光率具有相关性.在高流量、低透光率的情况下,理论计算的数值更接近于生物验证数值.相对于理论计算,生物验证是确定紫外线反应器剂量反应曲线的可靠方法.     

微污染原水预臭氧化-强化混凝处理及其安全性

以强化混凝和臭氧氧化技术为核心建立了中试水处理设备,采用有机物表观分子量分级、树脂分级等手段表征了原水有机物及其THMFP特征;通过实验室试验和中试运行对预臭氧和强化混凝技术应用中有机物去除效果、消毒副产物THM的产生和消除进行了研究;研究了臭氧应用中可能形成的相关副产物甲醛、溴酸盐等对饮用水安全性影响的问题.结果表明:预臭氧-强化混凝处理效果较好,采用适当浓度的臭氧(如1.0mg·L-1)进行预氧化,可以有效提高有机物去除率,从常规混凝滤后水的33.7%提高到48%,有机物浓度降到1.385mg·L-1;THMFP总体去除效果从常规处理的131μg·L-1降至53μg·L-1;未出现甲醛、溴酸盐超标的问题,对余铝没有显著影响,安全性较高;但是,AOC含量比常规混凝和强化常规混凝升高,可能增进微生物的繁殖和对管网等的腐蚀,需要进一步控制.