电絮凝法处理含铬电镀废水的研究

以铁片为电极极板,采用电絮凝法处理含铬电镀废水。考察了通电时间、pH值、电流密度、极板间距等因素对Cr(VI)的去除率的影响。结果表明:在通电时间为30min、pH值为4.0~6.0、电流密度为100A/m~2、极板间距为3cm的条件下,Cr(VI)的去除率达到99%以上。     

电絮凝废水中Cr(Ⅵ)高效去除工艺条件及机理研究

水体Cr(Ⅵ)污染因污染物来源广泛、毒性强,易形成水体-土壤复合污染,其绿色、低成本达标治理已成为国内外环保工作者关注的热点及难点问题。采用电絮凝工艺进行废水中Cr(Ⅵ)污染去除,探索液相pH、槽电压、电解质浓度及初始Cr(Ⅵ)浓度对电絮凝Cr(Ⅵ)去除效率的影响,并通过对所得沉淀絮体的微观形貌、元素分布及物相组成分析,阐明Cr(Ⅵ)电絮凝沉淀去除机理。结果表明,Cr(Ⅵ)电絮凝去除的最佳工艺条件为液相pH=6.0,槽电压3.0 V,电解质浓度2.0%,在此条件下,初始浓度10.0mg/L的含铬废水,经12.0min电絮凝反应,出水铬浓度为0.018mg/L,去除效率达99.98%,满足饮用水Cr(Ⅵ)排放限值。机理分析研究表明,废水中的Cr(Ⅵ)经Fe²⁺还原为Cr(Ⅲ)后,以CrOOH与Cr(OH)3的形式经铁的氧化物/氢氧化物载带沉淀而去除。电絮凝工艺治理水体Cr(Ⅵ)污染具有去除效率高、速率快、污泥产生量低的特点,可为水体Cr(Ⅵ)污染的治理提供技术支持。     

Treatment of dairy industry wastewater by EC and EF processes using hybrid Fe?Al plate electrodes

BACKGROUND: In this study electrochemical treatment of dairy industry wastewater (DW) was investigated using a combined electrode system consisting of iron and aluminum as sacrificial electrodes. The dairy industry generates strong wastewaters characterized by high biological oxygen demand and chemical oxygen demand concentrations. Dairy industry waste effluents are concentrated in nature, and the main contributors of organic load to these effluents are carbohydrates, proteins and fats originating from the milk. Since dairy waste streams contain high concentrations of organic matter, these effluents may cause serious environmental problems. RESULTS: A pole changer device was employed to change polarization in given time intervals to generate iron and aluminum based coagulants respectively. The effects of current density, initial pH, sodium sulfate (Na₂SO₄) and H₂O₂ concentrations on the removal efficiency were investigated. The best experimental conditions obtained in electrochemical studies were as follows: current density = 15 mA cm^?2, natural pH, without supporting electrolyte addition, H₂O₂ concentration = 3 × 1000 mg L^?1. Under these conditions, 79.2% COD removal from DW was achieved. CONCLUSION: According to the results, 20 min electrolysis is enough, since insignificant variations in COD removal were observed after this time. These methods were found to be successful for the treatment of DW. Copyright © 2011 Society of Chemical Industry     

Removal of Humic Acid from Groundwater by Electrocoagulation

With this study, we investigated an approach of applying an electrocoagulation method for the removal of humic acid from groundwater.Aluminium electrodes were selected in the experiment.Some major experimental factors, such as electrode distance, current densities and pH values were explored.Results suggest that, given a small electrode interval and/or a high current density, a lower pH value leads to an improved removal rate of humic acid.Under acid conditions with a current density 47.6 A/m2, for instance, humic acid concentrations were reduced from 20 mg/L to 0.43 mg/L which resulted in the removal of 97.8% of the humic acid.This encouraging result demonstrated that our electrocoagulation method is effective in the removal of humic acid from groundwater.     

电絮凝处理海水中污染物的研究

采用铁电极和铝电极对电絮凝处理受污染海水过程中浊度和化学需氧量(COD)去除效率进行了研究,试验结果表明:电絮凝处理海水工艺对浊度具有一定的去除效果,其去除率可达85%以上,铝电极的处理效果要好于铁电极。对电絮凝处理海水过程中COD的去除效率进行了试验研究,试验中发现电絮凝处理海水过程中剩余COD值与电流密度呈二级反应关系,并拟合出相应的动力学方程。     

周期换向脉冲电絮凝法处理屠宰场废水

以屠宰场废水为对象,应用周期换向脉冲电絮凝方法进行处理.在前期试验工作基础上(最佳直流电絮凝参数)讨论了周期换向脉冲参数:正反向频率,正反向占空比,正反向工作时间以及正反向电流密度比对废水的COD、色度去除率的影响.试验结果表明:在频率f_+=333 Hz、f_-=250 Hz,占空比r_+=30%、r_-=10%,工作时间t_+=40 ms、t_-=4 ms和电流密度分别为J_+=3.3 A·dm~(-2)、J_-=0.33 A·dm~(-2)的条件下进行电絮凝,废水的COD、色度去除率可达到85.4%、92.2%以上.并比较了直流、单脉冲和周期换向脉冲3种电絮凝方式处理COD相同的废水,所需能耗的关系是直流最大,单脉冲次之,而周期换向脉冲所需能耗最小.     

电絮凝技术在锌冶炼废水处理中的应用

介绍了电絮凝技术原理及工艺流程,与传统石灰/石灰石中和-铁盐法相比,该工艺具有工艺适应性强、运行成本低、污泥量少、占地面积小、操作简单等优点。水口山集团170 m~3/h锌冶炼废水电絮凝法深度处理系统已稳定运行一年多时间,处理后废水可全面达标排放,并且可回收金属铅7.2t/a、金属锌403.2t/a,该工艺具有良好的经济效益和环境效益     

电絮凝法深度处理石化工业废水的研究

采用电絮凝工艺深度处理石化工业废水,结果表明,影响COD去除率因素电极材料、电流密度、极板间水流速度,通过单因素分析得出,电絮凝工艺采用"铁-碳"电极,电流密度为44mA/cm2,极板间的水流速度6mm/s,CODcr、石油类的去除效率均在50%以上。     

应用铝和铁电极电化学处理酒精废醪蒸馏废水(英文)

Electrochemical treatment of distillery spent wash was carried out using different combinations of aluminum and iron electrodes in batch mode of operation.The spent wash was characterized for various parameters as per standard method of analysis and the treatment results were analyzed in terms of chemical oxygen demand(COD) removal efficiency of the spent wash.The experiments were performed to study the effect of operating parameters such as current density,pH of the spent wash,agitation speed,electrolysis time and the distance between the electrodes on the COD removal efficiency of the spent wash.It was observed that aluminum electrodes were more suitable for treatment of distillery spent wash as compared to iron electrodes.The maximum COD removal efficiency of 81.3% was obtained with Al-Al electrodes at the current density of 0.187 A·cm-2 and pH 3 for an electrolysis time of 2 h.     

三法净水一体化技术在污水处理中的应用

三法净水一体化技术是将电化学技术与传统的沉淀、过滤技术相结合,形成的一种新型高效的水处理技术。结合污水处理回用项目中试试验和工程实例总结了该技术的应用情况,分析了存在的问题,并从工艺优化和设计完善的角度提出了建议。