摘要
通过测定微电解处理皮革废水过程中液相pH值、总铁离子浓度的变化,比较相同总铁离子浓度下微电解与直接混凝法去除COD的效果,分析铁表面形态和沉积物构成,对铁/炭微电解处理皮革废水的作用机理进行探讨。结果表明,皮革废水中的有机物主要通过以下两种方式去除:一是微电解过程中产生的铁离子发生混凝沉淀作用,二是铁屑腐蚀过程中产生的氧化还原反应。酸性条件利于微电解作用效果。皮革废水因富含C1^-、S^(2-)等活性阴离子,促进腐蚀作用的发生,碱性条件(pH=9)下COD去除率仍达35%～55%。重复使用的铁屑表面会覆盖硫化物、氧化物等沉积物,影响微电解反应处理效果。降低进水pH值可溶解铁表面沉积物,改善微电解作用效果。填料内部形成的微观原电池和外加活性炭形成的外部宏观电池均可发生微电解反应,提高废水处理效果。
The present paper is to introduce the findings of our investigative study of the mechanism of treating tannery sewage by micro-electrolysis and the direct effect of micro-electrolysis material of the pure iron, its activated carbon, the industrial scrap iron and industrial scrap iron /the activated carbon in the reaction by measuring the pH changes and Fe2＋ concentration during the micro-electrolysis reactions. Comparing the chemical oxygen demand （COD） removal efficiency of the micro-electrolysis reaction, we have been trying to apply the micro-electrolysis method to treating the tannery sewage in combination with the analysis of the scanning electron microscope （SEM） and the energy detection spectrum （EDS）. The results of our investigation and analysis show that the organic matters in the sewage can be removed by the flocculation and redox reaction in the process of the micro-electrolysis with the former being contributed about 60% of the COD removal efficiency. While the process was repeated, the iron surface were covered with iron oxide and some other compounds, which may result in a great electronic transfer resistance, thus inhibiting the removal of the organic pollutants. Due to the violent corrosion of the scrap iron in the acidic condition, the removing efficiency of COD in this case under the influence of different materials would be rising on the whole by 30%-50% higher than that under the alkaline condition. In such a situation, the inner iron-carbon micro-battery and the external iron-carbon macro-battery would be formed in the scrap iron/activated carbon system, which helps to strengthen the micro-electrolysis effect and heighten the efficiency of the sewage treating.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2011年第2期103-107,共5页
Journal of Safety and Environment
基金
福建省科技计划重大项目(2005HZ03-3)
福建省自然科学基金项目(D0710019)
关键词
环境工程学
废水处理
微电解
皮革废水
机理分析
environmental engineering
wastewater treatment
micro-electrolysis
tannery wastewater
mechanism analysis
