BM二代菌去除电镀废水中重金属离子的效果研究

BM菌是一种能够高效去除电镀废水中重金属离子的新型功能菌群,实验研究了BM二代菌对Cr6+、Ni2+的最佳去除条件,结果表明:当水温为10~30℃,pH=2,Cr6+浓度为100 mg/L,反应10 min,菌废比为1∶200时废水中Cr6+的去除率达到98%以上;当水温为10~30℃,pH=8.5,Ni2+浓度为100 mg/L,反应10 min,菌废比为1∶200时废水中Ni2+的去除率达到96%以上;在相同条件下实际电镀废水中Cr6+和Ni2+的去除率均高于99%。     

微电解-生物法处理含铬电镀废水的研究

采用微电解生物法组合工艺处理含铬电镀废水,在实验过程中,电镀废水中的重金属离子通过微电解法预处理可去除90%以上,剩余部分被后续工艺的微生物功能菌去除。实验结果表明对Cr6+含量为50mg/L,Cu2+含量为15mg/L,Ni2+含量为10mg/L的废水,经处理后,重金属离子的净化率达999%,且无二次污染。     

淀粉基黄原酸盐处理重金属废水的条件优化研究

采用淀粉基黄原酸盐处理含重金属的电镀废水 ,对淀粉基黄原酸盐的用量、pH值和反应时间等条件进行了研究。结果发现 ,1L含氰电镀废水 (含Cr3+15mg/L、Cu2 +3mg/L、Ni2 +9.2mg/L和Zn2 +6mg/L) ,加入 1g淀粉基黄原酸盐 ,调节 pH为 8,搅拌 1h ,过滤 ,处理后的废水中Cr3+、Cu2 +、Zn2 +和Ni2 +残余浓度分别为 0 .0 8mg/L、0 .0 1mg/L、0 .1mg/L和 0 .0 8mg/L。含有重金属盐的残渣 ,可用硝酸处理 ,以回收重金属     

腐殖酸树脂处理含Pb2+、CU2+、Ni2+废水的研究

利用泥炭为原料制备腐殖酸树脂.在动态条件下,研究了腐殖酸树脂对重金属离子Pb2+、Cu2+和Ni2+的吸附效果及吸附条件.同时探讨了腐殖酸树脂对重金属离子Pb2+、Cu2+和Ni2+的吸附与解吸再生机理,吸附机理研究表明,腐殖酸树脂对重金属离子Pb2+、Cu2+和Ni2+的主要吸附形式为离子交换吸附和络合吸附.结果表明,在废水pH值为5.0～7.0,Pb2+、Cu2+和Ni2+浓度分别为50 mg/L,经腐殖酸树脂处理,Pb2+、Cu2+和Ni2+去除率可达98%以上,且处理后废水近中性.含Pb2+、Cu2+和Ni2+电镀废水经腐殖酸树脂处理后,废水中Pb2+、Cu2+和Ni2+含量显著低于国家排放标准.     

利用芦竹修复重金属污染湿地的研究

研究了芦竹(Arundodonaxlinn)对Cu2+、Ni2+、Cr6+重金属污染湿地的响应和对该污染湿地的影响。实验结果表明,芦竹对这3种重金属离子有一定的耐受性,并有不同程度的吸收,Cu2+、Ni2+和Cr6+去除率分别为63.8%,42.3%和34.4%。芦竹在100mg/kg浓度的Cu2+、Ni2+污染湿地中生长正常,在低浓度(55mg/kg)Cr6+污染中能存活,但生长速度较慢。在100mg/kg浓度Cr6+污染湿地中,出现急性中毒现象,半月后致死。在重金属污染环境中,芦竹普遍出现失绿现象,但除高浓度Cr6+(100mg/kg)以外,都能正常存活,表现出较强的适应性。     

红螺菌R-04吸附多种重金属的研究

研究了红螺菌R 0 4对重金属Cu2 + 、Ni2 + 和Cr6+ 的吸附行为。实验表明 ,菌体分别在含 1 0～ 5 0mg/LCu2 + 、Ni2 + 和Cr6+ 的培养液中培养 96h ,最高吸附率分别为 98 9%、90 %和 84 % ;且菌体对Cr6+ 的还原率均达 99%以上。另外 ,观察到 5 0mg/LCu2 + 的培养液 ,菌液褪色 ;而在Ni2 + 和Cr6+ 中没有出现这种现象。最后 ,探讨了共存离子对吸附的影响 ,3种金属离子两两组合、三者共存对菌体吸附Cu2 + 和Cr6+ 的影响不大 ,对Ni2 + 的影响较大     

铁酸锰纳米材料吸附含Ni~(2+)电镀废水的性能研究

采用非表面活性剂水热法制备了铁酸锰(MnFe2O4)纳米材料吸附剂,研究了吸附时间、溶液pH和温度对MnFe2O4纳米材料吸附模拟含Ni 2+电镀废水和实际含Ni 2+电镀废水中重金属Ni 2+的吸附性能,并探讨了该材料的再生利用性能。结果表明,MnFe2O4纳米材料可有效吸附电镀废水中的Ni 2+,吸附平衡时间为600min。对20mg/L的模拟含Ni 2+电镀废水,投加4.5mg的的MnFe2O4纳米材料进行吸附处理,Ni 2+的吸附去除率高达98%左右;实际工程应用中,应保持电镀废水偏碱性、温度25℃;MnFe2O4纳米材料具有理想的再生利用性能,重复吸附5次后,吸附去除率仍可达82.24%,在实际废水处理中具有广阔的应用前景。     

Cu2+和Cr6+对活性污泥处理系统的冲击影响研究

以完全混合活性污泥反应器为试验系统,在作为处理对象的实际餐饮废水中添加Cu2+和Cr6+,分批试验发现添加单一Cu2+的I#系统中,随着Cu2+浓度的增加,污泥浓度及生物相无明显的变化,Cu2+的去除率比较稳定,在90%左右波动;在同时添加Cu2+和Cr6+的Ⅱ#系统中,污泥量明显减少,生物相发生变化,Cr6+浓度达到4.8mg/L,污泥对Cr6+和Cu2+的去除率分别降至27.50%和37.89%.可见,Cr6+对活性污泥系统的毒性远大于Cu2+.     

离子浮选法处理电镀废水实验研究

进行离子浮选法处理电镀废水的研究,对影响因素pH、CA∶CMe(摩尔比)、离子强度、浮选时间和通气量等进行了实验研究。实验结果表明:离子分离选择性递减顺序为:Cd2+Zn2+Fe2+Cu2+Ni2+。当CA∶CMe为2.5～3∶1,pH为8.5～9,离子强度不高于0.0001 mol/L时,离子浮选对镉、锌、铜、镍等金属离子均有很高的去除率,Cd2+、Zn2+、Fe2+、Ni2+、Cu2+残余浓度最低分别可达0.05、0.20、0.22、0.28和0.33 mg/L,处理后的电镀废水各污染物浓度均达到排放标准。泡沫产品中镉、锌、铜、镍品位分别达到3.2%、9.3%、18.1%和13.2%,具有极高的资源回收价值。     

嗜酸硫杆菌和黑曲霉对电镀污泥重金属浸出效果

电镀污泥重金属浸出对电镀污泥资源化利用具有重要意义。为了降低处置成本,采用嗜酸硫杆菌与黑曲霉对电镀污泥重金属浸出效果进行了研究。结果表明,采用嗜酸性氧化硫硫杆菌和氧化亚铁硫杆菌混合菌种对含固率为3%的电镀污泥进行为期15 d(培养驯化后)的处理后,污泥中Ni、Cr与Cu的浸出率虽分别高达92.8%、85.0%和96.8%,但耗时久,无法大规模地实际应用。利用黑曲霉对电镀污泥进行为期6 d的处理,Ni、Cr和Cu的浸出率分别达到92.0%、74.4%和55.3%。若采用黑曲霉培养15 d后产生的生物有机酸和同pH的柠檬酸处理电镀污泥4 h后,两者对Ni、Cr和Cu的浸出率分别为:85.0%与94.2%、63.8%与73.7%、57.9%与99.6%。可见,利用黑曲霉发酵菌液浸出电镀污泥中重金属有一定的实际应用价值。     

化学-混凝沉淀处理含氟含重金属废水研究

为解决某铝材电镀工业园含氟含重金属废水达标排放的问题，研究了化学混凝沉淀法同时处理该废水中氟与金属的效果及影响因素，采用正交和单因素实验确定了最佳工艺条件。结果表明，当CaCl₂投加量与废水中氟离子摩尔比为5∶1（即CaCl_{质量4 782 mg/L），聚氯化铝（PAC）用量为500 mg/L，pH为9.5，聚丙烯酰胺（PAM）用量2 mg/L时，出水中残留F离子浓度可降至8 mg/L，Cu²⁺、Ni²⁺、Cr⁶⁺和Zn²⁺出水浓度分别降至0.05、0.07、0.3和0.1 mg/L，出水能达到《水污染物排放限值》（DB44/26-2001）第二时段一级标准，且最为经济。}     

电混凝处理电镀综合废水

采用电混凝法处理酸性电镀综合废水，首先研究了不同电流密度对总氰化物、重金属和化学需氧量（COD）去除率的影响。实验结果表明，电混凝可有效去除酸性电镀综合废水中的氰化物与重金属。随着电流密度的增大，总氰化物与重金属的去除率逐渐提高。当电流密度为10mA／cm2时，废水中残留的总氰化物、Cu2＋、Ni2＋、Cr6＋和Zn2＋ 的浓度分别为23．0、25．0、4．5、0．2和0．2mg／L。为了进一步提高去除率，在电化学体系中添加H2O2，随着H2O2投量的增大，总氰化物、重金属、COD去除率不断提高。当H2O2投量为3mL／L时，处理过废水中残留总氰化物、Cu2＋、Ni2＋、Cr6＋、Zn2＋和COD的浓度分别为0．2、2．0、3．0、1．5、0．1和220mg／L。     

Removal of chromium from synthetic plating waste by zero-valent iron and sulfate-reducing bacteria.

Experiments were conducted to evaluate the potential of zero-valent iron and sulfate-reducing bacteria (SRB) for reduction and removal of chromium from synthetic electroplating waste. The zero-valent iron shows promising results as a reductant of hexavalent chromium (Cr+6) to trivalent chromium (Cr+3), capable of 100% reduction. The required iron concentration was a function of chromium concentration in the waste stream. Removal of Cr+3 by adsorption or precipitation on iron leads to complete removal of chromium from the waste and was a slower process than the reduction of Cr+6. Presence SRB in a completely mixed batch reactor inhibited the reduction of Cr+6. In a fixed-bed column reactor, SRB enhanced chromium removal and showed promising results for the treatment of wastes with low chromium concentrations. It is proposed that, for waste with high chromium concentration, zero-valent iron is an efficient reductant and can be used for reduction of Cr+6. For low chromium concentrations, a SRB augmented zero-valent iron and sand column is capable of removing chromium completely.     

Competitive adsorption characteristics of Co2+, Ni2+, and Cr3+ by IRN-77 cation exchange resin in synthesized wastewater

Adsorption properties of Co2+, Ni2+, and Cr3+ on an Amberlite IRN-77 cation exchange resin were investigated in batch systems. Levels of adsorption rapidly approached an equilibrium state within 1 h. The adsorption characteristics of each metal onto the resin were accurately represented by Langmuir isotherms. Co2+ and Ni2+, which have an equivalent electrovalence, displayed similar levels of adsorption onto the resin when they coexisted in the solution. However, when Cr3+ was added to the solution it competitively replaced Co2+ and Ni2+ ions that had been previously adsorbed onto the resin, resulting in the desorption of these metals into the solution. The result was likely due to a higher adsorption affinity of Cr3+ relative to Co2+ and Ni2+. This implies that interactively competitive adsorption of multi-cations onto the resin should be thoroughly considered when contemplating the efficient operation of an ion exchange process in the treatment of industrial wastewater.     

Utilization of Modified Attapulgite for the Removal of Sr(II), Co(II), and Ni(II) Ions from Multicomponent System,Part I: Kinetic Studies

Radionuclide sorption by natural and modified clays is extensively accepted to be an important process from the radioactive waste point of view. This work focused on modification of natural attapulgite with a layered double hydroxide to produce a novel chemisorbent for Sr2+, Ni2+, and Co2+ removal from multicomponent solution. The structural and surface characteristics of both attapulgite (ATP) and modified attapulgite (LDH-ATP) were investigated using XRD, FTIR, SEM, and thermal analysis. Comparison of sorption features of Sr2+, Ni2+, and Co2+ onto ATP and LDH-ATP was achieved; the results indicated that LDH-ATP was the most efficient sorbent for Sr2+, Ni2+, and Co2+. Kinetic studies established that the sorption is fast and reaching >90% within 30 min. The sorption of Sr2+, Ni2+, and Co2+ are well defined by non-linear pseudo-second-order model and controlled by an intra-particle diffusion mechanism. The diffusivity was determined using homogeneous surface diffusion (HSDM) model and found in the order 10−13 m2/min; this confirmed that the sorption of the three ions is chemisorption process. LDH-ATP can be employed as a candidate chemisorbent for the removal of some metal ions from waste solution.     

电镀污泥回收重金属的新工艺

合理、经济地处理混合电镀污泥,回收其中有价值的金属具有重要意义。以不同的酸作为浸出剂对电镀污泥中的金属进行了浸出效果实验。结果表明,在相同条件下,各酸的浸出效果顺序为:硫酸>盐酸>王水>硝酸;液体水与固体电镀污泥比为3,干污泥为5 g,硫酸加入量为15 mL,时间1 h条件下,混合电镀污泥中金属铜锌的浸出率最大,达到97.38%。分别采用铁和铁锰合金还原剂常温还原低熔点重金属离子铜、锌,浸出液中99%以上含量的铜、锌沉淀,使低熔点重金属与黑色金属铁、锰、铬有效分离。低熔点混合重金属可以用来做铜合金添加剂使用,最后沉淀的混合黑色金属氢氧化物处理后可以用来做炼钢合金添加剂使用。     

Effect of operational parameters on heavy metal removal by electrocoagulation

In the present paper, the performance of electrocoagulation (EC) for the treatability of mixed metals (chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)) from metal plating industrial wastewater (EPW) has been investigated. The study mainly focused on the affecting parameters of EC process, such as electrode material, initial pH, distance between electrodes, electrode size, and applied voltage. The pH 8 is observed to be the best for metal removal. Fe–Fe electrode pair with 1-cm inter-electrode distance and electrode surface area of 40 cm² at an applied voltage of 8 V is observed to more efficient in the metal removal. Experiments have shown that the maximum removal percentage of the metals like Cr, Ni, Zn, Cu, and Pb are reported to be 96.2, 96.4, 99.9, 98, and 99.5 %, respectively, at a reaction time of 30 min. Under optimum conditions, the energy consumption is observed to be 51.40 kWh/m³. The method is observed to be very effective in the removal of metals from electroplating effluent.