摘要
动电技术是去除污泥中重金属的有效方法。在动电去除污泥中重金属的过程中，污泥的pH值是影响重金属去除效率的主要影响因素。以福州快安污水处理厂污泥为研究对象，采用HNO，为酸化剂，将污泥的pH值由初始的6．03调节为1．05、2．30、3．26和4．66，在电压梯度为1V／cm，通电时间为5d的条件下进行系列动电试验，探讨污泥pH值与重金属Ph的去除率之间的关系。结果表明，污泥的pH值越低，Pb的动电去除率越高。污泥的pH值为1．05、2．30、3．26、4．66和6．03时，对应的1#区域Ph的去除率分别为48．5％、47．9％、33．7％、32．3％和27．4％。研究表明，降低污泥的pH值可以改变重金属Ph的赋存形态，增强Pb的迁移性，提高Ph的动电去除效率。
The presence of heavy metals is one of the main obstacles for agricultural use of sewage sludge. Electrokinetie treatment can be applied to remove heavy metals from sludge. This method uses a lowlevel electrical energy and is known for removal of heavy metals like lead, copper and the metalloid arsenic from sludge. The driving force is the migration of those ions in the sludge body by the applied elec- tric field. In most cases the heavy metals are concentrated near the cathode depending on the actual pH value and the solubility products of formed non-soluble compounds. Sometimes it is also possible to deposit heavy metals directly at the cathode surface, pH value influ- ences the reactions of the heavy metals during such an electrochemical process. Therefore, the relationship between pH value of sludge and the removal efficiency of Pb was studied. This article took the sludge from Kuai＇ an sewage treatment plant as the research object. After acidified with HNO3, the pH values of sludge were 1.05, 2.30, 3.26, and 4.66 respectively. After five days experiments at voltage gradient 1.0 V/cm, removal efficiency of Pb at part 1# were 48.5%, 47.9%, 33.7% and 32.3% respectively which are 21.1%, 20.5%, 6.3%, 4.9% higher than not acidified sewage sludge. Study shows lower the pH value of sludge can change the distribution of Pb by transfer of its different fractions into more mobile forms and improve the removal efficiency of Electrokinetic treatment of Pb.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2010年第5期39-41,共3页
Journal of Safety and Environment
基金
福建省教育厅基金项目(JA08169)
关键词
环境工程学
PH值
PH
动电技术
去除效率
environmental engineering
pH value
Pb
electrokinetic technology
removal efficiency
