植物阴极-沉积型微生物燃料电池处理含铬废水

应用植物阴极-沉积型微生物燃料电池(PC-SMFC)系统处理含铬废水及沉积物,探究了阴极材料和植物对PC-SMFC系统去除污染物效果及产电性能的影响。结果表明,以不锈钢网为阴极集电装置、菖蒲为植物的PC-SMFC装置的处理效果最佳,当上覆水Cr⁶⁺初始浓度为108.14mg/L、COD初始浓度为978 mg/L时,可获得的最大输出电压和输出功率密度分别为0.499 0 V和14.87 mW/m²,对上覆水中COD、Cr⁶⁺的去除率分别为93.66%和99.29%,对沉积物中有机质和Cr⁶⁺的去除率分别为15.69%和79.11%,对总铬的固定率为65.33%。经PC-SMFC系统处理后,各装置沉积物中生物有效态铬向较为稳定的铁锰结合态和残渣态铬转化,即PC-SMFC对稳定沉积物中的铬具有促进意义。     

电絮凝处理脱硫废水中重金属及动力学模型

采用电絮凝法处理脱硫废水中重金属离子,研究去除过程的影响因素及动力学模型,并对电絮凝产物进行分析。考察电絮凝时间、电流密度、废水pH值、曝气量对电絮凝法处理重金属离子效果的影响。结果表明,电絮凝时间40min,电流密度4mA/cm2,废水pH=7,曝气量0.4m3/h时,四种金属去除率达90%。电絮凝产物为铁的多核羟基络合物,且去除过程具有一级动力学反应特征。     

改良Bardenpho-臭氧-BAF处理工业园区污水

广西某工业园区污水处理厂主要出水指标要求满足《地表水环境质量标准》(GB3838—2002)Ⅳ类标准(TN≤10 mg/L除外),设计采用“水解酸化+改良Bardenpho +高效沉淀池+臭氧接触氧化+BAF+反硝化滤池+接触消毒”工艺。其中水解酸化池采用脉冲布水方式,水力停留时间 8.1 h;改良 Bardenpho总停留时间 24 h,混合液内回流比 150%～250%,污泥龄 15 d,采用可提升式曝气系统,气水比9.6∶1;二沉池表面负荷0.75 m³/(m²·h);高效沉淀池表面负荷9.92 m³/(m²·h),总停留时间 60.5 min;臭氧接触池停留时间 60 min,投加浓度 20 mg/L;曝气生物滤池水力负荷 3.04m³/(m²·h),COD 去除负荷 1.46 kg/(m²·d);反硝化滤池正常滤速 5.76 m/h,强制滤速 7.2 m/h;接触消毒停留时间30 min,次氯酸钠投加浓度8～10 mg/L。...     

高出水标准要求下高含氟工业废水处理实践

某液晶面板厂的高含氟高硬度废水处理厂的进水分为含氟废水及有机废水两股,含氟废水经过混凝沉淀+MBBR硝化预处理,降低硬度、F^-及NH₃-N浓度后与有机废水混合,再采用生化处理+臭氧高级氧化+曝气生物滤池+高效沉淀+消毒组合工艺处理,最终出水水质稳定达到地表水Ⅳ类标准。该项目规模为6×10⁴m³/d,吨水投资约5 935元/m³,单位占地面积为0.619 m²/(m³·d^-1)。     

电絮凝法处理电脱盐废水的实验研究

采用曝气和温度调节对电脱盐废水进行预处理,并通过电絮凝方法对电脱盐废水进行破乳除油。 实验结果表明：一定的曝气可以起到均质调节作用,曝气15min时不稳定指数最大,而此时TOC也最大,说明通过曝气改变了体系的稳定状态;反应过程中一定的升温和曝气作用都可以有效提高处理效率,电絮凝处理电 脱盐废水的过程中,最佳电流密度为5mA/cm2;从紫外三维荧光谱图可以看出,电絮凝过程破坏了物质的结构;采用电絮凝法处理电脱盐废水,可以有效去除废水的COD和浊度。     

铁催化内电解法预处理染料中间体废水的研究

研究了铁催化内电解法对染料中间体废水的预处理效果,考察了初始pH、曝气时间、铁投加量、催化反应时间等因素的影响。结果表明,在初始pH值为4、曝气时间为3 h、铁投加量为100 g/L、催化反应时间为30~60 m in的条件下,预处理效果最佳,对COD和色度的去除率可分别达到58.51%和89.07%,废水的COD浓度和色度可分别从5 047 mg/L和6 832倍降至2 094mg/L和747倍。     

废润滑油再生废水处理工程调试及运行研究

采用物化预处理+两级厌氧/好氧+改进型高密度曝气生物流化床(MABFT)组合工艺处理废润滑油再生废水,处理规模为150 m³/d。运行结果表明,处理后出水COD、氨氮和总氮分别为44、1和25 mg/L,平均去除率分别为98.7%、99.9%和94.7%,出水水质均达到《污水综合排放标准》(GB 8978—1996)的三级标准和江苏省盱眙县第二城市污水处理厂纳管标准。该处理工艺具有处理效果好、运行稳定、耐冲击负荷能力强且维护方便等特点,直接运行费用为21.68元/m³。     

用响应面法优化小球藻絮凝沉降工艺的研究

以氢氧化钙为絮凝剂,对海水小球藻Chlorella vulgaris絮凝工艺效果进行了试验研究。单因素试验结果表明,当絮凝时间为60⁸0 min、氢氧化钙添加量为0.680 min、氢氧化钙添加量为0.6⁰.8 g/L和藻液pH为80.8 g/L和藻液pH为8¹0时,最有利于小球藻的采收。在单因素试验的基础上,利用响应面法对小球藻的絮凝条件进行了优化,建立了二次回归模型。通过分析得出:各因素对小球藻采收率均有极显著性影响(P<0.01),影响次序为氢氧化钙添加量>絮凝时间>藻液pH;絮凝时间与藻液pH以及氢氧化钙添加量与藻液pH的交互作用对小球藻采收率均有极显著性影响(P<0.01)。利用回归方程预测小球藻的最佳絮凝条件,当絮凝时间为77 min、氢氧化钙添加量为0.7 g/L、小球藻液pH为9.3时,小球藻的采收率可达93.9%。     

废水处理工程设计实例及运行效能分析

为解决某养殖场200 t/d废水处理问题,文中采用“絮凝沉淀预处理+接触氧化法+MBR”工艺对废水进行处理,工程稳定运行后,出水水质COD_cr约为134.4 mg/L、NH₃-N约为36 mg/L,远低于GB 18596—2001《畜禽养殖业污染物排放标准》排放标准限值,并介绍了工艺流程及构筑物的相关设计参数。效能分析表明,该工程运行费用为1.9元/m³废水,日运行费用378元,低于同类处理工程。     

纳米二氧化钛光催化氧化降解苯酚废水实验

开展实验室模拟苯酚废水的二氧化钛光催化氧化实验。结果表明：在苯酚废水曝气量为0～3L/min的条件下,随着曝气量的增大,COD去除率先增大后减小;初始浓度不变,光照时间为1h的条件下, 调节pH值在3～11,苯酚废水COD去除率随着pH值的增大而减小,当pH值为11时, COD去除率又开始增 大,酸性条件比碱性条件下COD去除率高;随着二氧化钛投加量的增加,COD去除率增大,当二氧化钛投加量 为10g/L时,COD去除率反而降低,二氧化钛最佳投加量为3g/L;随着苯酚废水初始浓度由75mg/L增加至300mg/L,COD去除率由78.2％降低到58.1％;反应温度的改变对COD和TOC的去除率没有影响。     

电凝聚法去除废水中重金属离子Cr6+、Cu2+的研究

考察了初始pH值、电解时间、电流强度、NaCl投量、离子共存及曝气量等因素对电凝聚法处理含Cr6+、Cu2+废水的影响。结果表明,随初始pH值的升高,对Cr6+的去除率呈先上升后下降的趋势,并在pH值=6时达到最高,而对Cu2+的去除率逐渐上升,并在pH值=5时达到最高后趋于稳定;对Cr6+、Cu2+的去除率均随反应时间及电流强度的增大而增大,并在时间为20min、电流强度为4 A时达到了比较稳定的去除效果;NaCl投量对Cr6+、Cu2+的去除率基本没有影响,其作用是适当地提高废水的电导率,降低能耗;对混合溶液中Cr6+、Cu2+的去除效果比单一溶液时好,金属离子共存对电凝聚处理重金属废水起促进作用;适当的曝气会提高重金属的去除率。     

流化态三维电极降解水相2,4-二氯酚的研究

采用流化态三维电极反应器处理水相2,4-二氯酚,考察了曝气强度、粒子电极密度及溶液的初始pH等因素对电解效果的影响。结果表明,以此反应器处理水相2,4-二氯酚,在表观电流密度为15 mA/cm2、曝气强度为120 m3/(h.m2)、粒子电极密度为30 g/L、pH值为4的条件下,反应120 min后,对2,4-二氯酚的去除率达到98.4%。可见,采用流化态三维电极反应器处理水相2,4-二氯酚是完全可行的。     

Fe-H2O2深度处理造纸中段废水的研究

为解决零价铁法处理废水时效率偏低的问题,采用Fe-H2O2法对造纸中段废水的二级处理出水进行了深度处理,分别考察了pH值、反应时间、铁炭比、曝气量和H2O2投量对色度和COD去除率的影响.结果表明：在pH值为3.5、铁炭比（体积比）为1.2、曝气量为1.4 L/min、铁屑粒径为60～80目、H2O2投量为40～60 mg/L的最优条件下,当处理时间控制在35 min时,对色度和COD的去除率可分别达到98%和77%左右,出水可回用.     

硫自养波形潜流人工湿地的脱氮机理及工况优化

将硫自养反硝化工艺与潜流人工湿地相结合,考察了其对低碳氮比污水中氮的去除效果。结果表明,增加曝气装置后硫自养波形潜流人工湿地的脱氮效果可以得到保障,在气水比为8∶1、水力负荷为0.8 m³/(m²·d)时,TN去除率为(70±5)%,出水TN浓度低于8 mg/L;NH4+-N去除率在90%以上,出水NH4+-N浓度低于3 mg/L;COD去除率为(50±2)%,出水COD浓度低于40 mg/L;p H值可维持在7~9。同时,石灰石填料具有同步除磷的效果。该工艺具有脱氮效率高、效果好、运行费用低的特点。     

直流电絮凝法处理油田采出水试验研究

针对油田采出水高盐、高油的特点,采用电絮凝法对油田废水进行处理,考察了电解时间、极板间距、初始pH值及电流密度等对油及浊度去除效果的影响。结果表明,电絮凝技术处理油田采出水效果好,出水含油量达到《碎屑岩油藏注水水质推荐指标及分析方法》（SY/T 5329—1994）的A级注水标准,对浊度也有一定的去除效果,该方法技术上可行且有广泛的应用前景。     

Textile Wastewater Treatment With Activated Sludge And Powdered Activated Carbon

The objective of the study is to determine the effectiveness of batch activated sludge process and powdered activated carbon adsorption for organic and color removal from textile wastewaters. Factors affecting treatment performance investigated in the study included raw wastewater strength, various combinations of dye to starch in the wastewater, aeration time. Synthetic wastewaters using starch solution and disperse-red-60 dye were used in the adsorption study. The 3 wastewater strengths used included low, medium and high strength. The 5 different dye to starch combinations used included 0% dye+100% starch, 25% dye+75% starch, 50% dye+50% starch, 75% dye+25% starch, and 100% dye+0% starch. The batch bio-oxidation was conducted for a period of 24 hours. The COD removal efficiency, color removal, bio-oxidation rate constant, F/M ratio, SVI, pH and temperature were determined. The results indicated that starch was much easier to remove by the batch activated sludge process compared to disperse-red-60 dye, which was virtually non-biodegradable. Wastewaters containing 100% starch had the highest COD removal efficiency. Increase in dye concentration in wastewater resulted in decrease in the COD removal efficiency. The COD removal efficiency ranged from 6 to 45% for low strength wastewater of 100mg/L COD, 27 to 80% for medium strength wastewater of 500mg/L COD, and 23 to 65% for high strength wastewater of 1000mg/L COD. The low strength wastewaters had the best settling characteristics, while the medium strength wastewaters had the worst. For high PAC dosage of 15g/L, high COD removal efficiencies of 88 to 98% removal and E * ab of 36 to 47 were obtained. It is recommended that activated sludge be used to remove high COD organic pollutants first, followed by PAC adsorption to remove dye waste in the treatment of textile wastewaters.     

Electrochemical oxidation of table olive processing wastewater over boron-doped diamond electrodes: treatment optimization by factorial design

The electrochemical treatment of an effluent from edible olive processing over boron-doped diamond electrodes was investigated. The effect of operating conditions, such as initial organic loading (from 1340 to 5370 mg/L chemical oxygen demand (COD)), reaction time (from 30 to 120 min), current intensity (from 5 to 14 A), initial pH (from 3 to 7) and the use of 500 mg/L H2O2 as an additional oxidant, on treatment efficiency was assessed implementing a factorial experimental design. Of the five parameters tested, the first three had a considerable effect on COD and total phenols removal, while the other two were statistically insignificant. In most cases, high levels of phenols degradation and decolorization were achieved followed by moderate mineralization. The analysis was repeated at more intense conditions, i.e., initial COD up to 10,000 mg/L, reaction times up to 240 min and current up to 30 A; at this level, the effect of treatment time and applied current was far more important than the starting COD concentration. Treatment for 14 h at optimal conditions (30 A and an initial loading of about 10,000 mg/L) led to 73% COD removal with a zero-order kinetic constant of 8.5mg/(L min) and an energy consumption efficiency of 16.3 g COD/(m3 A h).     

Influence of mixed liquor recycle ratio and dissolved oxygen on performance of pre-denitrification submerged membrane bioreactors

The conflicting influence of mixed liquor recycle ratio and dissolved oxygen on nitrogen removal and membrane fouling of a pre-denitrification submerged MBR was investigated in this study. It was found that a high aeration rate of 10 L air/min was able to minimize membrane fouling as compared with lower aeration rates of 5 and 2.5L air/min in this study. Faster fouling at lower aeration rate was due to the decrease in cross-flow velocity across the membrane surface. However, high DO concentration (average of 5.1+/-0.5mg O2/L) present in the recycle mixed liquor at an aeration rate of 10 L air/min deteriorated the TN removal efficiency when operating at a recycle ratio of more than 3. A lower aeration rate of 5L air/min, resulting in an average DO concentration of 3.4+/-0.7 mg O2/L in the recycle mixed liquor, led to an improvement in TN removal efficiency: 63%, 80%, 84% and 89% for mixed liquor recycle ratio of 1, 3, 5 and 10, respectively. Further decrease in aeration rate to 2.5L air/min, resulting in an average DO concentration of 1.9+/-0.8 mg O2/L, did not improve the TN removal efficiency. Using a newly developed simplified nitrification-denitrification model, it was calculated that the COD/NO3(-)-N required for denitrification at 10 L air/min aeration rate was higher than those associated with 5 and 2.5L air/min aeration rates. The model also revealed that denitrification at an aeration rate of 10 L air/min was limited by COD concentration present in the wastewater when operating at a mixed liquor recycle ratio of 3 and higher.     

低DO下曝气方式对分段进水脱氮工艺的影响

采用分段进水生物脱氮工艺处理小区生活污水,考察了在低DO条件下,不同曝气方式对硝化率及污泥沉降性能的影响。结果表明,在曝气量为0．27m^3／h、MLSS平均为2700mg／L左右、好氧区的DO为0．26～2．5mg／L的条件下,当进水氨氮为44～55mg／L时,对氨氮的去除率保持在95％以上,对COD的去除率〉90％;当控制好氧区第1、2格室的DO分别为0．5～0．7和1．0～1．2mg／L时,系统的硝化率维持在90％以上,出水中的氨氮〈2mg／L;在恒定曝气量下,向进水中投加有机碳源,当水质改变较快时,容易引起丝状菌污泥膨胀,但通过恒DO曝气控制,可使污泥的沉降性能得到改善。     

Enhanced electrocoagulation–electroflotation for turbidity removal by Opuntia ficus indica cladode mucilage

The optimisation of the electrocoagulation‐electroflotation (EC‐EF) process assisted by the mucilage of the Opuntia ficus indica (OFI), on the turbidity removal was performed through the response surface methodology (RSM). For a solution of 300 mg/L of silica gel, high turbidity removal (93.14% ± 1.31) was obtained under the optimal conditions of 2.5 mg/L, 21.2 V, 9.65 and 2.61 mS/cm for the mucilage concentration, voltage, pH and conductivity, respectively, this experimental value was close to the predicted value of 92.96% ± 0.3. OFI mucilage increases turbidity removal efficiency and reduces specific energy consumption at a fixed current density. The turbidity removal of the EC‐EF process was improved by 30.94% compared with the conventional EC–EF (EC–EF without OFI mucilage) which shows 62.02% ± 1.45 of turbidity removal.