Enhanced removal of organic matter and typical disinfection byproduct precursors in combined iron–carbon micro electrolysis-UBAF process for drinking water pre-treatment

The organic matter and two types of disinfection byproduct(DBP) precursors in micropolluted source water were removed using an iron–carbon micro-electrolysis(ICME)combined with up-flow biological aerated filter(UBAF) process. Two pilot-scale experiments(ICME-UBAF and UBAF alone) were used to investigate the effect of the ICME system on the removal of organic matter and DBP precursors. The results showed that ICME pretreatment removed 15.6% of dissolved organic matter(DOM)and significantly improved the removal rate in the subsequent UBAF process. The ICME system removed 31% of trichloromethane(TCM) precursors and 20% of dichloroacetonitrile(DCAN) precursors. The results of measurements of the molecular weight distribution and hydrophilic fractions of DOM and DBP precursors showed that ICME pretreatment played a key role in breaking large-molecular-weight organic matter into low-molecular-weight components, and the hydrophobic fraction into hydrophilic compounds, which was favorable for subsequent biodegradation by UBAF.Three-dimensional fluorescence spectroscopy(3D-EEM) further indicated that the ICME system improved the removal of TCM and DCAN precursors. The biomass analysis indicated the presence of a larger and more diverse microbial community in the ICME-UBAF system than for the UBAF alone. The high-throughput sequencing results revealed that domination of the genera Sphingomonas, Brevundimonas and Sphingorhabdus contributed to the better removal of organic matter and two types of DBP precursors. Also, Nitrosomonas and Pseudomonas were beneficial for ammonia removal.     

Nitrite pre-treatment of dewatered sludge for microbial fuel cell application

The effect of pre-treatment of dewatered sludge using different nitrite concentrations and pH for microbial fuel cell (MFC) application was investigated. The results show that the addition of nitrite was feasible to increase the solubilization rate of the sludge and may reduce mass transfer limitation at the anode. This helped the MFC to reach higher voltage and to generate more power. The higher free nitrous acid (FNA) concentration under the acidic condition helped to increase sludge solubilization. However, under an alkaline condition, during which the FNA concentration was relatively low, the solubilization of the sludge was higher. The highest voltage and power density produced was 390?mV and 153?mW/m², respectively, with the addition of nitrite at 100?mg-N/L and pH?9. Furthermore, it was found that elevated levels of FNA could inhibit electrogenic bacteria thus reducing power generation.     

Enhancement in biodegradability of distillery wastewater using enzymatic pretreatment

A combined treatment technique consisting of enzymatic hydrolysis, followed by aerobic biological oxidation was investigated for the treatment of alcohol distillery spent wash. The enzyme cellulase was used for the pretreatment step with an intention of transforming the complex and large pollutant molecules into simpler biologically assimilable smaller molecules. Batch experiments were performed in order to analyze the influence of various parameters like pretreatment time, enzyme concentration and pH during the pretreatment step on the subsequent aerobic oxidation kinetics. The rate of aerobic oxidation was enhanced by 2.3 fold for the pretreated sample as compared to the untreated sample when the pH during the pretreatment step was maintained at a value of 4.8. Similarly, a two fold increase in the aerobic oxidation rate was found when the effluent was pretreated with the enzyme, without any pH control (i.e. effluent pH of 3,8). The study indicated that the enzymatic pretreatment of the effluent could be one of the successful pretreatments which can lead to enhancement of the rate of the subsequent aerobic oxidation.     

高锰酸钾复合药剂对煤矿生活污水深度处理的强化混凝效应

在煤矿生活污水深度处理的混凝处理前,投加高锰酸钾复合药剂（PPC）预处理,研究了PPC的对混凝处理的强化效应。实验结果表明：PPC预处理对煤矿生活污水深度处理的混凝处理具有很好的强化效应,能显著提高聚合氯化铝（PAC）的对CODMn和浊度的去除率;当PPC的投加量为4 mg/L时,CODMn和浊度的去除率分别提高21%和40%。     

滨海化工区废水预处理去毒技术耦合工艺研究

化工产业是天津滨海新区重要的支柱产业,该行业废水是滨海污染物控制的主要威胁。针对常规单一方法存在的问题,试验选取滨海某化工区实际废水从内电解-Fenton、内电解-混凝、内电解-超声及微波强化氧化-光催化4种耦合去毒预处理工艺进行了研究。试验表明,与传统方法相比,内电解-Fenton法中H2O2的加入增加了污染物的降解途径,提高了对污染物的去除效率;内电解-混凝法对于制药废水的生物毒性有比较好的去除作用,不加PAM或Ca(OH)2的效果更佳;内电解-超声法对制药废水的生物毒性去除率可达92%,其可生化性提高45%;微波强化氧化-光催化法对大多数难降解物质有效,而对酚类物质降解效果不佳。     

铁炭曝气微电解对炸药废水的试验研究

采用铁炭曝气微电解对炸药废水进行预处理,处理结果表明:当炸药废水调节pH值为2,反应时间2h,物质A投加量2g/L,铁屑与活性炭体积比为1∶1时,进水TOC为2600mg/L,COD为2500mg/L,NH3-N为190mg/L,出水TOC为250mg/L,COD为400mg/L,NH3-N为20mg/L,去除率分别为90.5%、82%和89.6%,BOD5/COD由0.16提高到0.38。     

焦化废水处理新工艺

焦化废水因含有难降解和对生物有抑制性的物质而较难处理。在不加稀释水的条件下,采用物化预处理/生化/膜生物反应器(MBR)工艺对宣化钢铁公司的焦化废水处理进行中试研究。并同焦化厂现有工艺进行了比较。结果表明:经物化预处理提高废水的可生化性以及MBR对生化出水的强化处理后,新工艺对COD、NH3-N等的去除效果较现有工艺有明显改善,正常生产情况下出水可达标排放。     

利用给水厂污泥预处理畜禽养殖废水

实验考察了直接回用未脱水的给水厂污泥(undewatered water treatment sludge,UWTS)做絮凝剂进行畜禽养殖废水预处理的可行性.单因素实验结果表明,随着投加量和pH的增加,出水悬浮物浓度(suspended solid,SS)、化学需氧量(chemical oxygen demand,COD)和总磷(total phosphorus,TP)的去除率不断增加;随着快速搅拌速度的提高,UWTS的絮凝效果呈现先增强后减弱的趋势;随着沉淀时间的延长,出水中SS、COD和TP的去除率起初逐渐增大,但15 min后去除率变化不明显.进一步的正交实验分析结果表明,UWTS回用做絮凝剂的最佳反应条件为投加量2 800 mg/L,快速搅拌速度300 r/min,沉淀时间15 min,此时对应的SS、COD和TP的去除率分别为74.8％、54.6％和60.5％.最佳反应条件下的粒径分析结果表明,UWTS的投加使得粒径范围在40 ～ 180 μm的颗粒物得到了去除.尽管与商品化絮凝剂相比,UWTS的絮凝效果略差,但是,利用其预处理畜禽养殖废水具有成本优势,因而具有应用潜力.     

常温常压多相催化氧化处理有机工业废水进展

简介了有机工业废水常温常压多相催化氧化技术的工艺原理及特点,并对近年来国内外该技术在典型有机工业废水如印染废水、医药废水、有机化工废水等处理中的研究和应用情况进行了评述。最终展望了该技术的研究重点及未来的发展方向。     

电解预处理-UASB-CASS工艺处理糠醛废水

对电解预处理-UASB-CASS工艺处理糠醛废水进行了研究,通过试验确定了电解预处理阶段主要影响因素为电流强度大小和电解时间,极板间距对COD去除率影响不大;电解预处理最佳工艺参数为:电流强度0.3 A,电解时间4 h,极板间距30 mm.在此条件下COD去除率为20.6%,废水可生化性提高了38.1%.加上后续的UASB-CASS工艺,出水COD浓度＜150 mg/L,满足《污水综合排放标准》(GB8978-1996)二级排放标准.