内电解-厌氧-好氧工艺处理制药废水试验研究

采用“内电解-厌氧-好氧”工艺处理混合制药废水，试验证明：在厌氧段HRT=120h，好氧段HRT=48h条件下，当混合废水进水CODcr约为18600mg／L时．总COD去除率可达90％以上，出水达到GB8978-96二级排放标准。     

生物膜法处理2,3-二甲基苯胺废水试验研究

采用缺氧折流板生物膜和循环移动载体生物膜反应器处理2，3－二甲基苯胺废水，结果表明，缺氧折流板反应器具有厌氧滤池和厌氧折流板反应器的优点，当水力停留时间为10．5h(缺氧5．5h，好氧5h)时，系统去除率可达89．7％。     

混凝-厌氧膨胀床-好氧流化床组合工艺处理有机氯农药废水

研究了物化与生化两种预处理方法及组合的好氧生化处理工艺对该废水的处理效果。研究表明：物化预处理混凝法,可使COD和色度去除率分别达26．5％和37、5％,但废水的可生化性仅有微弱改善;生化预处理采用厌氧膨胀床工艺废水B／C值由进水的0．24提高到出水的0、41,可生化性有了较大的改善,COD和色度平均去除率分别为76．5％和99．5％;好氧流化床在有机物容积负荷为4．08-7．76kgCOD／m^3·d,水力停留时间为4h,气水比为30-35时,COD、色度平均去除率为84．9％、93．3％。试验表明,好氧流化床具有运行稳定、抗冲击负荷强的特点。混凝、厌氧膨胀床预处理与好氧流化床的工艺组合可使该废水处理后达到污水综合排放标准（GB8978．96）的二级标准。     

水力停留时间对SBR工艺脱氮除磷效果的影响分析

以西安市第四污水处理厂初沉池实际出水为研究对象,研究了SBR试验装置中HRT对有机物、氮、磷的去除效果。结果表明,HRT对COD、PO43--P的去除效果影响较小,对TN和NH4+-N的去除影响较大。TN和NH4+-N的去除率随好氧停留时间、缺氧停留时间的增加而增大。试验装置在缺氧段、好氧段停留时间分别为5 h、3.5 h的运行条件下,对COD、NH4+-N和TN的平均去除率分别达到了86%、98%和74%,出水水质除TP之外,均达到了城镇污水处理厂污染物排放标准(GB 18918-2002)一级A排放标准要求,试验结果为SBR工艺污水厂升级改造提供了工艺运行参数,也可供同类型污水处理厂工艺升级改造设计时参考。     

酸洗除垢技术在海上油田的应用

针对活性污泥法处理综合医药废水容积负荷低、出水水质不稳定的问题,设计了以生物膜为核心的厌氧／兼氧／好氧组合工艺,并在现场进行了为期半年的中试研究。试验包括生物膜培养驯化、快速降解和稳定运行三个阶段,在稳定运行阶段总水力停留时间平均为84h,混凝沉淀出水COD平均为353mg／L,对COD的平均去除率达到95．6‰硝化池出水氨氮平均为1mg／L,去除率为99．5％,     

油田采出水的高温水解-好氧处理工艺研究

根据油田采出水的水质特征，采用厌氧(水解)-好氧(接触氧化)处理工艺。实验表明，虽然油田采出水的BOD5／CODCr，较低，属于难生物降解废水，但是当温度为50～60℃时，选择厌氧停留时间为6h，好氧停留时间为3．5h，气水比为10～20，可使其出水的CODCr稳定在120mg／L左右。如果排除Cl^-产生的影响，CODCr，约为60～70mg／L，达到GB8978-1996一级排放标准。     

水解酸化-SBR工艺处理味精废水

利用水解酸化-SBR工艺对味精废水处理进行了试验研究，试验结果表明：在水解酸化水力停留时间为8h、SBR反应时间为6h、水温为20～25℃的条件下，CODcr和NH3-N的去除率均达92％以上，出水水质可以达到污水综合排放标准（GB8978-88）二级标准。表明以水解酸化作为预处理可有效提高味精废水的可生化性，对缩短好氧生物处理反应时间，降低能耗和     

悬浮填料单元在活性污泥改造中的应用

将悬浮填料装填入格网,制成体积一定的悬浮填料单元。分别投入曝气池的厌氧区和好氧区,形成悬浮填料和活性污泥复合工艺中试系统。然后,考察在复合系统在不同填料填充率、曝气量和水力停留时间的氨氮去除率。我们发现最优条件下,氨氮去除率较高,复合系统最稳定。最优条件为：填充率为35%;好氧段曝气量为5 m3/h,厌氧段曝气量为0.3 m3/h;水力停留时间为8 h。在此条件下,氨氮去除率比活性污泥工艺提高了18%。     

生物膜法缺氧-好氧工艺处理磺胺生产废水

采用生物膜法缺氧-好氧工艺处理磺胺生产废水，当进水COD为2357mg/L时，出水COD可达到284.3mg/L，去除率达87.92%。试验研究结果表明：温度对工艺运行效果影响很大，当系统温度满足25℃时，缺氧段和好氧段HRT分别为8.1h和21.3h，工艺运行即可达到如上效果；当缺氧段温度降至15℃时，缺氧段和好氧段HRT分别延长至12.7h和33.1h，才可达到同样的效果，但好氧段温度必须满足25℃，才能使出水COD达到300mg/L以下的目标。     

A/O工艺处理含己内酰胺化纤废水的试验研究

采用A/O工艺对含己内酰胺化纤废水进行连续动态试验。结果表明,在缺氧段与好氧段的容积比为1:2,水力停留时间48 h、BOD5污泥负荷0.15 kg/(kg.d)、混合液回流比为250%～300%时,COD去除率均达到95%以上,氨氮和总氮去除效果显著,出水达到天津市污水综合排放标准(DB 12/356-2008)二级标准。     

橡胶助剂CBS废水处理的试验研究

本文以物理方法为主对高浓度难降解橡胶促进剂CBS废水进行了试验研究。试验结果表明所采用的组合十艺十分有效，COD从40000mg/L降到150mg/L以下，COD总去除率达到99.6%以上，色度从150倍降到0，脱色率达到100％，出水可以达标排放。     

High performance electrocoagulation process in treating palm oil mill effluent using high current intensity application

Electrocoagulation process using high current intensity to treat palm oil mill effluent(POME) was investigated in this study.Various operating parameters such as electrolysis time, inter-electrode distance and initial pH were carried out to determine the efficient process condition on the removal of chemical oxygen demand(COD),biological oxygen demand(BOD) and suspended solids(SS).The highest treatment was achieved at 50 min with the removal efficiencies for COD, BOD and SS obtained as 85%, 83%, and 84%, respectively.More than 50 min treatment showed the fluctuated trends of removal efficiencies which can be considered insignificant.The application of higher current resulted in higher removals of organics while the gas bubbles also assisted in removing the pollutant particles by floatation.In an inter-electrode distance study, the removal efficiency decreased when inter-electrode distance was either higher or lower than 10 mm due to the increase of solution resistance and the decrease of anode active surface area.In initial pH study, it was found that high removal efficiencies were achieved in slightly acidic POME sample rather than in neutral or basic condition.An electrocoagulation process by using the optimum operating parameters was able to remove COD, BOD and SS up to 95%, 94% and 96% respectively.The experimental results confirm that application of high current intensity in electrocoagulation provided high treatment efficiency at a reduced reaction time.     

Container washing wastewater treatment by combined electrocoagulation–electrooxidation

Treatment of container washing wastewater (CWW) by using combined electrocoagulation (EC)–electrooxidation (EO) process was studied. CWW contains many organic compounds such as surfactants used in cleaning agents. Wastewater was first treated by EC with iron (Fe) and aluminum (Al) electrodes. The process performance was measured according to the removal efficiencies of soluble chemical oxygen demand (sCOD) and color. Maximum sCOD removal efficiency was found 82% and color removal efficiencies were 95%, 95% and 98% at 436, 525 and 620 nm, respectively, with Fe electrodes under 25 mA/cm² current density, initial pH of 5 and 120-min operation time. Because of the low sCOD removal efficiency, EO was used as post-treatment process by using boron doped diamond electrode (BDD). sCOD removal efficiency was increased to 89% and color removal efficiencies decreased to 72%, 64%, 71% at 436, 525 and 620 nm, respectively, under 25 mA/cm² current density, initial pH of 3 and 300-min operation time. This study showed that electrochemical processes caused new complex molecules formation in the CWW, which caused deterioration of water color and limited the process efficiency.     

A one-step electrochlorination/electroflotation process for the treatment of heavy metals wastewater in presence of EDTA

This study demonstrated the feasibility of simultaneous removal of heavy metals and EDTA in an electrolytic undivided cell equipped with Ti/RuO₂ as anode and stainless steel as cathode. In absence of EDTA, results show that nickel and copper removal by EF process is pH sensitive. In addition, nickel and copper may be substantially removed by EF. Removal efficiencies were 99.6% and 97%, respectively. In presence of EDTA, the metal removal by the EF process was inhibited. The inhibition rate was found to be dependent on EDTA/metal molar ratio. A one-step process, involving the combination of two techniques electrochlorination (EC) and electroflotation (EF), was set thanks to chloride addition. In situ generated active chlorine allowed the decomplexation of M-EDTA. Then, free metal ions were removed by precipitating and subsequent floating to the surface by rising electrogenerated bubbles. The obtained results revealed that, with 0.6 EDTA/metal molar ratio, removal efficiencies were 77% and 78% for nickel and EDTA, respectively, in the case of nickel–EDTA solutions. Removal efficiencies were 89% and 96% for copper and EDTA, respectively, in the case of copper–EDTA solutions. Furthermore, heavy metal removal efficiency by the combined process showed to be affected by chloride content and current intensity.     

不同臭氧生物活性炭工艺对二氯乙腈前体物的去除效能

以典型的含氮消毒副产物(N-DBPs)--二氯乙腈(DCAN)为例,研究臭氧-上向流生物活性炭(O3-UBAC)工艺和臭氧-下向流生物活性炭(O3-DBAC)工艺的去除效能差异,并结合DON、分子量分布、亲疏水性和三维荧光光谱探究其差异机理。结果表明,O3-UBAC工艺对DCAN生成势(DCANFP)、DON、分子量<3 kDa的有机物、亲疏水性有机物,以及芳香族蛋白质和类可溶性生物产物有机物的平均去除率分别为58.31%、61.60%、49.22%、46.60%、62.17%和82.08%,而O3-DBAC工艺对相应指标的平均去除率分别为48.72%、50.79%、21.16%、27.32%、47.37%和43.04%。因此,O3-UBAC工艺比O3-DBAC工艺对DCAN前体物的净化效能要好。     

Removal efficiencies of endocrine disrupting chemicals by coagulation/flocculation, ozonation, powdered/granular activated carbon adsorption, and chlorination

Removal efficiencies of endocrine disrupting chemicals (EDCs), bisphenol A and nonylphenol, during various types of water treatment processes were evaluated extensively using laboratory- and pilot-scale experiments. The specific processes of interest were coagulation/flocculation sedimentation/filtration (conventional water treatment process), powdered activated carbon (PAC), granular activated carbon (GAC), ozonation and chlorination. Batch sorption tests, coagulation tests, and ozone oxidation tests were also performed at higher concentrations with 14 EDCs including bisphenol A. The conventional water treatment process had very low removal efficiencies (0 to 7%) for all the EDCs except DEHP, DBP and DEP that were removed by 53%, 49%, and 46%, respectively. Ozonation at 1 mgO₃/ L removed 60% of bisphenol A and 89% of nonylphenol, while chlorination at 1 mg/L removed 58% and 5%, respectively. When ozone and chlorine doses were 4 and 5 mg/L, respectively, both EDCs were not detected. PAC removal efficiencies ranged from 15% to 40% at 3 to 10 mg/L of PAC with a contact time of 15 minutes. In the high concentration batch sorption tests, EDC removal efficiencies by PAC were closely related to octanol-water partition coefficient (K_ow). GAC adsorption was very effective water treatment process. The type and service time of GAC did not affect EDC removal efficiencies. The combination of ozonation and GAC in series appears to remove EDCs effectively to safe levels while conventional water treatment could not.     

Statistical analysis and optimization of simultaneous biological nutrients removal process in an intermittently aerated SBR

Simultaneous removal of carbon and nutrients from a synthetic wastewater in aerobic/anoxic sequence batch reactor (SBR) was investigated. The experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). Two significant independent variables, cycle time and aeration time, were studied to analyze the process. Five dependent parameters—total COD (TCOD) removal, total nitrogen removal, total phosphorus removal, total Kjeldahl nitrogen removal and effluent nitrate concentration—were monitored as the process responses. The region of exploration for the process was taken as the area enclosed by cycle times (2, 4.25 and 6.5 h) and aeration times (30, 40 and 50 min/h) boundaries. The maximum COD (87.18%) and TKN (78.94%) removal efficiencies were obtained at the cycle time and aeration time of 6.5 h and 50 min/h, respectively. While the maximum TN (71.15%) and phosphorus (68.91%) removal efficiencies were obtained at cycle time of 6.5 h and aeration time of 40min/h. As a result, high cycle time (6.5 h) and moderate aeration time (40min/h) were found to be the optimal region for maximum carbon and nitrogen removal efficiencies.     

Simultaneous Recovery of Nickel and Cobalt from Aqueous Solutions using Complexation-Ultrafiltration Process

Simultaneous recovery of nickel and cobalt from aqueous solutions by complexation-ultrafiltration process with polyethylenimine (PEI) was studied. Experiments were performed as a function of polymer/metal ratio (P/M), solution pH, and ionic strength. Effects of concentration time on metal rejection and membrane flux were also studied. At optimum experimental conditions of pH 6.0 and P/M 5.0, the nickel removal efficiency reaches at 99.9% and cobalt removal efficiency goes to 96.4%. Both nickel and cobalt removal efficiencies decreased as the adding salt concentration increases. During 12 h of the ultrafiltration process, the decline of membrane flux was less than 16% and the removal efficiencies for both nickel and cobalt were kept almost constant. Diafiltration was further performed to regenerate PEI. The removal efficiencies for both metals using recycled PEI were found to be close to those with the original PEI. Results from the two-step process of complexation-UF and decomplexation-UF separation showed that it could be a promising method for simultaneous recovery of nickel and cobalt from aqueous solutions.     

A comparative study of electrocoagulation and electro-Fenton for food industry wastewater treatment: Multiple response optimization and cost analysis

ABSTRACT

In this study, response surface methodology was applied for food wastewater by electrocoagulation (EC) and electro-Fenton (EF) processes. The optimum conditions for the chemical oxygen demand (COD) removal were found to be 21.36 min, pH 10 and 86 mA/cm² in EC, whereas 27.11 min, pH 2.38, 86 mA/cm² and H₂O₂/COD:2 in EF process. COD removal efficiencies were determined to be 29.4% for EC and 59.1% for EF processes and higher than 99% total suspended solids removal efficiencies were achieved. It can be concluded that high COD removal was obtained (4998 mg/L COD removal by EC and 10,047 mg/L COD removal by EF).     

城市污水深度脱色技术研究进展

城市污水厂二级生物处理出水中的色度物质构成复杂且难以处理,随着排放标准日益严格和再生水用量的不断提高,解决色度问题逐渐成为研究热点。本文介绍了色度的概念和组成,总结了国内外研究者利用混凝、氧化技术、膜过滤技术和组合工艺去除色度的效果和机理,分析了影响其脱色效果的因素,并简要评述了各项技术的应用前景。总结发现,纳滤（去除率90%～100%）、臭氧及光催化及其组合工艺（60%～80%）效果最优,其次是混凝、超滤及其组合工艺（50%）,而微滤、含氯氧化剂及紫外照射工艺脱色效果较差。最后对本领域的发展前景作了展望,提出研究色度物质的来源及构成,关注脱色工艺性能及复色的可能性,以及实现脱色、消毒和去除微量有机物的多功能性,将是未来的研究重点。