胶团强化超滤法同时去除废水中Cd2+和亚甲基蓝

采用阴离子表面活性剂十二烷基硫酸钠(SDS),考察了胶团强化超滤(MEUF)法对含有Cd2+和亚甲基蓝(MB)染料复合废水的处理效果,同时考察了SDS浓度、pH值、温度对去除效果和渗透性能的影响。结果表明,在Cd2+和MB浓度分别为50和6 mg/L的条件下,当SDS浓度为1.0 cmc(临界胶团浓度)时去除效果最好,此时对Cd2+和MB的去除率分别达到98.4%和97.3%,对SDS的去除率为95.9%;pH值对Cd2+的去除效果影响较大,Cd2+去除率随pH值的上升增加明显,MB去除率则无明显变化;随着温度的上升,对Cd2+和MB的去除率都有所下降。     

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。     

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。     

UV/Fenton光催化氧化法处理液晶显示屏清洗废水

采用UV/Fenton光催化氧化法处理难生物降解、含高浓度表面活性剂的液晶显示屏清洗废水,考察了反应时间、亚铁盐及双氧水投加量、UV光强、体系pH、有机物初始浓度等对处理效果的影响。结果表明,当初始pH值为3~7.2时,经2 h左右的反应后可将废水的COD值由1 468 mg/L降至100 mg/L以下。对COD的去除率随反应时间的延长而增大并最终趋于平稳,合适的反应时间约为2 h。当H2O2与Fe2+的物质的量之比较低时,对COD的初始去除率较高。合适的FeSO4.7H2O投加量为543.5 mg/L,双氧水投加量为2.5~3 mL/L,且一次性投加即可。增加紫外光光强、投加TiO2等对有机污染物的去除有显著促进作用。     

高分子重金属絮凝剂PEX处理电镀废水研究

以电镀废水为处理对象，研究了高分子重金属絮凝剂PEX对废水中重金属离子、浊度及有机污染物的处理效果；同时考察了废水pH值对重金属离子去除效果的影响及重金属离子的回收率。结果表明，当废水pH≥6．0时，pH值的变化对重金属去除率的影响不大；在pH=6．5～7、PEX的投量为160mg／L时，对镍的去除率〉95％，对铜和铬的去除率〉99％，对有机物的去除率为64％；重金属离子的回收率随盐酸浓度的增大而提高，当盐酸浓度为15％时对镍离子的回收率为70％，对铜离子的回收率为24％左右。     

Fenton试剂降解内分泌干扰物双酚A的研究

采用单独Fe<'2+>、单独H<,2>O<,2>和单独Fenton试剂去除水中内分泌干扰物双酚A(BPA),考察了Fe<2+>与H<,2>O<,2>的投加量、pH值以及BPA初始浓度对BPA降解效果的影响.研究表明,单独Fe<'2+>和单独H<,2>O<,2>都不能有效去除BPA,而Fe<'2+>与H<,2>O<,2>联用后生成的Fenton试剂对BPA具有良好的去除效果.在BPA初始浓度为5 mg/L、Fe<'2+>投加量为5.6 mg/L(以FeSO<,4>·7H<,2>O计)、H<,2>O<,2>投量为7 mg/L、pH值为3.94的条件下,反应30 min后对BPA的去除率高达99.12%.在低投加量范围内,随着Fe<'2+>和H<,2>O<,2>投量的增加,对BPA的去除率迅速提高,当其投量提高到一定水平后则去除率不再提高.pH值对BPA的降解影响显著,当pH值为3.94时对BPA的去除率最高.BPA初始浓度对其降解效果几乎没有影响.     

氧化锌光催化/超滤膜组合工艺对水中富里酸的去除

以富里酸(FA)为模拟废水,探究了ZnO投量、溶液初始pH值、曝气量等因素对自制氧化锌光催化过程去除效能的影响,考察了光催化/超滤膜组合工艺对FA的去除效果以及过滤不同光催化氧化时间的FA溶液时膜通量的变化,并利用扫描电镜(SEM)分析了由FA引起的不可逆膜污染。结果表明,光催化氧化反应最佳条件如下:Zn O投加量为0.3 g/L、FA溶液初始p H值为7、曝气量为1.2 L/min,在此条件下光催化反应150 min后,对UV_(254)及TOC的去除率分别可达到92.6%和56.2%。超滤膜组合工艺不仅可以实现催化剂与处理水的有效分离,且随着光催化时间的增加,膜通量衰减速度下降,有效减缓了FA溶液造成的不可逆膜污染。     

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.     

三维电极/电-Fenton法处理苯胺废水影响因素的试验研究

为研究三维电极/电-Fenton法对降解苯胺废水的影响因素,以优化三维电极/电-Fenton法处理苯胺废水的工艺条件,在自制三维电极电解槽中,以苯胺废水为处理对象,分别研究溶液的pH值、Fe~(2+)投加量、电解质(Na_2SO_4)投加量、曝气量四种因素对三维电极/电-Fenton法降解苯胺效果的影响情况。试验结果表明:当电解反应时间达到60min,电解电压为15V,极板间距为8cm时,控制溶液体系的pH值为3.0,Fe~(2+)浓度为0.7mmol/L,电解质投加量为1.8g/L,曝气量为0.8m~3/h,对苯胺和COD的去除率最高可达89.85%和90.69%。三维电极/电-Fenton法处理苯胺废水的效果较好。     

新型絮凝剂APAC处理含Cr(Ⅵ)废水的研究

采用新型絮凝剂APAC处理含Cr(Ⅵ)的模拟废水,考察了各因素对Cr(Ⅵ)及浊度去除效果的影响。结果表明:该絮凝剂对Cr(Ⅵ)有很好的去除能力,对Cr(Ⅵ)的去除率最高可达92.65%;废水的pH越高,对Cr(Ⅵ)的去除率越大;APAC中的凹凸棒组分对Cr(Ⅵ)的去除起主要作用;当APAC的盐基度为80%、投量为32 mg/L、废水的pH值为7~12时,对Cr(Ⅵ)和浊度的去除效果较佳。APAC絮凝剂对Cr(Ⅵ)的良好去除效果为含铬废水的处理提供了一条新思路。     

不同重金属离子对C S H凝胶影响及其固化稳定性

通过溶液法人工合成不同钙硅比C-S-H凝胶,借助XRD,SEM,XPS,TEM,ICP等测试方法,分析研究了CSH凝胶对不同种类、不同含量重金属离子(Cr3+,Cr6+,pb2+,Zn2+,Cd2+等)的俘获能力及其稳定性.结果表明:钙硅比不同,CSH凝胶对重金属离子固化稳定性及其固化机制均存在一定差异,高钙硅比CSH凝胶对重金属离子固化稳定性较强;重金属离子种类及价态不同,其在C-S-H凝胶中的结合方式及固化能力也不同,其中CSH凝胶对Cu2+,Cd2+,Zn2+等离子的固化能力较强,对Cr6+的固化能力较弱.水化液相中,CSH凝胶对Cr3+,pb2+,Zn2+等多种重金属离子的固化能力低于其对单一重金属离子的固化能力;水化液相中Cr6+的存在,会对CSH凝胶对pb2+的固化及其稳定性产生巨大影响,而Cr3+的存在对其影响则较小.     

PPC去除水源水中突发性重金属铜和锌污染研究

通过正交试验设计和单纯性优化试验设计模拟了地表水铜含量超标3倍、锌含量超标4倍的情况下,采用高锰酸盐复合药剂(PPC)强化去除这两种重金属的最优应急预案。结果表明,常规工艺对锌的去除率不到10%,对铜的最大去除率为30%;组合工艺去除铜的最优条件是:聚铝投加量为20 mg/L,PPC投加量为5 mg/L,pH值为9,PPC在混凝后1 min投加,此时铜的去除率在90%以上;组合工艺去除锌的最优条件是:聚铝投加量为20 mg/L,PPC投加量为4 mg/L,pH值为8,PPC在混凝前1 min投加,此时锌的去除率在90%以上。     

脉冲电絮凝处理电镀废水的工艺优化与应用

以实际电镀厂废水为研究对象,采用铁电极板电絮凝技术,考察比电流、溶液初始pH值、占空比和曝气强度等参数对废水中镍和铬去除效果的影响,并利用响应面法优化了电絮凝工艺。结果表明,当比电流为122 A/m^3、占空比为48%、初始p H值为7. 1、曝气强度为2. 4 L/L时,电解30 min后,对Ni²⁺、Cr⁶⁺和总铬的去除率分别为99. 65%、100%、100%,比能耗为0. 757kW·h/m^3,与传统的单因素试验相比,降低了11. 87%。实际工程废水的处理规模为30 m^3/h,400多天的运行效果表明,经响应面优化的电絮凝工艺运行稳定,出水水质达标。     

Crab shell for the removal of heavy metals from aqueous solution

The ability of crab shell to remove heavy metals from aqueous solution was evaluated by comparing with that of several sorbents (cation exchange resin, zeolite, granular activated carbon, powdered activated carbon). All experiments were conducted using several heavy metal ion solutions (Pb, Cd, Cu, Cr). The orders of heavy metal removal capacity and initial heavy metal removal rate were found as crab shell > cation exchange resin > zeolite > powdered activated carbon>granular activated carbon. Therefore, crab shell is satisfactory as a good biosorbent for the heavy metal removal. The study indicates that the removal of these heavy metals is selective, with Pb and Cr being removed in preference to Cd and Cu. The sorption equilibrium of heavy metal ions on sorbents was modeled on the applications of Langmuir and Freundlich.     

Cellulose/chitin beads for adsorption of heavy metals in aqueous solution

We successfully prepared the biodegradable cellulose/chitin beads by coagulating a blend of cellulose and chitin in 6 wt% NaOH/5 wt% thiourea aqueous solution with 5% H2SO4 as coagulant, and investigated the adsorption of heavy metals (Pb2+, Cd2+, Cu2+) from an aqueous solution on the beads by atomic absorption spectrophotometer. Batch adsorption experiments were carried out as a function of ion concentrations, initial pH, ionic strength, temperature, adsorption time and desorption time. The results revealed that the cellulose/chitin beads could adsorb effectively Pb2+, Cd2+ and Cu2+ ions, and the uptakes of Pb2+, Cd2+ and Cu2+ ions on cellulose/chitin beads were 0.33 mmol/g at pH0 4, 0.32 mmol/g at pH0 5 and 0.30 mmol/g at pH0 4, respectively. Experimental results also showed that the adsorption of these heavy metals was selective to be in the order of Pb2+ > Cd2+ > Cu2+ in a low ion concentration solution. The adsorption equilibrium time of these heavy metals on beads was 4-5 h, but the desorption time was 5-15 min. Moreover, these beads could be regenerated up to about 98% by treating with 1 mol/L HCl aqueous solution. The mechanisms for the removal of free heavy metal ions by cellulose/chitin beads was based on mainly complexation adsorption model, as well as a affinity of hydroxyl groups of the materials on metals. Therefore, we developed new environment-friendly beads prepared by a simple produce process for removal and recovery of heavy metals.     

Evaluation of heavy metal removal from aqueous solution onto scolecite

Scolecite is a zeolite associated to basalts of the Parana Continental Igneous Province (PCIP South America). The potential of scolecite as a new material for heavy metal removal (Pb2+ Cu2+, Zn2+, Ni2+, Co2+ and Cd2+) from aqueous solutions is evaluated. The experiments were carried out by immersion of 0.5 g of sample in solutions containing the metal ions, and kept under constant agitation for 24h, at ambient temperature. The meq of cations retained per mass of scolecite was evaluated as a function of: initial concentration (5-60 mg L(-1)), pH (4-6), liquid/solid ratio (200, 1000 and 2000) and particle size. The results indicated a great affinity of scolecite for Cu2+ with a retention value of 130 microeq g(-1) at pH 6, Ci = 30 mg L(-1) and liquid/solid ratio of 200. In the same conditions, the maximum retention measured for the other ions were 64 microeq g(-1) (Zn2+), 56 microeq g(-1) (Pb2+), 31 microeq g(-1) (Ni2+), 7.8 microeq g(-1) (Co2+) and 3.2 microeq g(-1) (Cd2+). These values increase substantially when the L/S ratio is increased. The affinity of copper and lead for scolecite is discussed based on their free ionic forms (i.e., their hydrated bivalent ions) and their hydrolysis products. The remaining ions are retained as free ions.     

高压脉冲电絮凝与硅藻精土组合工艺处理电镀废水

电镀废水成分复杂,其中含有多种重金属离子,不适于生物降解,而化学处理工艺复杂、运行费用高。在生产性试验的基础上,对电镀综合废水采用高压脉冲电絮凝与硅藻精土组合技术处理,对Cr^6＋、Ni^2＋、Cu^2＋、COD的去除率分别达到99．77％、99．90％、100％和90％,出水各项指标均达到了排放标准。该工艺与传统化学处理法相比,具有处理效率高、速度快、占地省、操作方便、运行可靠、投资省、处理成本低的特点。     

Removal of divalent heavy metal mixtures from water by Saccharomyces cerevisiae using crossflow microfiltration

The removal of heavy metal ions, Ni2+, Cu2+ and Pb2+ using yeast (Saccharomyces cerevisiae) as carriers in a crossflow microfiltration is investigated. The effects of yeast cell and electrolyte concentrations on the transient and steady-state permeate flux and metal ion rejections are established. It is found that the metal ion rejection reaches a plateau if yeast cell concentration is greater than approximately 2 g/l as a result of cell aggregation. The binding affinity of the metals to yeast cell is Pb2+ > Cu2+ > Ni2+, which is also reflected in the metal ion rejection under identical process conditions. Because of the formation of yeast cell flocks in the presence of Pb2+, permeate flux is also higher for this metal. The presence of NaCl decreases both rejection and permeate flux for Ni2+ and Cu2+ but not for Pb2+. When binary or ternary metal mixtures are used, the rejection of the individual metals is reduced except that of Pb2+. It is found that the pseudo-gel concentration is unaffected by the presence of metal ions.     

Equilibrium and kinetics of metal ion adsorption onto a commercial H-type granular activated carbon: experimental and modeling studies

Systematic studies on metal ion adsorption equilibrium and kinetics by a commercial H-type granular activated carbon were carried out. Titration of the carbon showed that the surface charge density decreased with an increasing pH. Higher copper adsorption was obtained with increasing solution pH and ionic strength. Metal removal was in the descending order: Cu2+ > Zn2+ approximately Co2+. Copper removal was not affected by addition of zinc or cobalt, while copper can reduce both zinc and cobalt removal. Kinetic experiments demonstrated that the copper adsorption rapidly occurred in the first 30-60 min and reached the complete removal in 3-5 h. Removal of zinc and cobalt was slightly slower than that of copper. It was found that the mass transfer is important in the metal adsorption rate. The surface complex formation model was used successfully to describe the surface change density, as well as the single- and multi-species metal adsorption equilibrium. The copper removal was due to adsorption of Cu2+, CuOH+, and CuCl+, while the zinc and cobalt uptake was due to the formation of surface metal complexes of SOM2+ and SOMOH+ (M = Zn and Co). It was found that the diffusion-control model well described the adsorption kinetics with various metal ions and pH values. Finally sensitivity analysis on the kinetic model's parameters was carried out.     

中和/微滤工艺处理重金属酸性废水的试验研究

采用中和／微滤工艺处理重金属离子酸性废水,考察了pH值、搅拌方式和搅拌时间及投加絮凝剂对各金属离子去除效果的影响。结果表明,反应的最佳pH值宜控制在9．0-9．5;机械搅拌的处理效果要优于鼓风搅拌的,搅拌时间控制在60min左右为宜;投加絮凝剂有助于对金属离子的去除,且加入絮凝剂后混合液中的颗粒粒径变大,分布较为集中。