Abstract

Currently, electrochemical oxidation is a very efficient method to treat many types of wastewaters. Under the effects of electrical current, toxic or non-biodegradable substances will be oxidized to become biodegradable or completely oxidized to CO₂ and H₂O. With the strengthening of environmental discharge legislations, tannery wastewater may have a negative effect on the environment because of its high pollution levels. In this study, for the first time, the tannery wastewater treatment after the activated sludge process digestion was carried out using electrochemical oxidation by SnO₂/Ti and PbO₂/Ti inactive anodes. Effects of current density, pH, stirring rate and reaction time on the pollutants removal efficiencies of tannery wastewater were studied. The results showed that SnO₂/Ti and PbO₂/Ti anodes can effectively remove over 80.0% of the color, chemical oxygen demand and total nitrogen in tannery wastewater after 90 min of reaction time at a current density of 66.7 mA/cm². SnO₂/Ti anodes gave higher pollutants removal efficiency in base environments, while PbO₂/Ti anodes offered higher pollutants removal efficiency in acidic environments. The current density and stirring rates significantly affected pollutant removal efficiencies, and the concentration of pollutants in the effluent decreased as reaction time was increased. In general, SnO₂/Ti anodes were found to be more effective than PbO₂/Ti anodes in the pollutants removal efficiency and energy consumption of tannery wastewater treatment.

Graphic abstract

中文翻译：

---

在非活性阳极上使用电氧化对活性污泥进行预处理后的制革废水处理

摘要

当前，电化学氧化是处理多种类型废水的非常有效的方法。下的电流的影响，毒性或不可生物降解的物质会被氧化成为生物可降解的或完全氧化成CO ₂和H ₂ O.随着加强环境排放法规的，制革废水可能对环境产生负面影响，因为其高污染水平。本研究首次采用SnO ₂ / Ti和PbO ₂电化学氧化法对活性污泥法消化后的制革废水进行处理。/ Ti无活性阳极。研究了电流密度，pH值，搅拌速率和反应时间对制革废水中污染物去除效率的影响。结果表明，SnO ₂ / Ti和PbO ₂ / Ti阳极在电流密度为66.7 mA / cm ^2的条件下反应90分钟后，可有效去除制革废水中80.0％以上的颜色，化学需氧量和总氮。SnO ₂ / Ti阳极在碱性环境中具有较高的污染物去除效率，而PbO ₂/ Ti阳极在酸性环境中具有更高的污染物去除效率。电流密度和搅拌速率显着影响污染物的去除效率，并且随着反应时间的增加，废水中污染物的浓度降低。通常，发现制革厂废水处理的污染物去除效率和能耗方面，SnO ₂ / Ti阳极比PbO ₂ / Ti阳极更有效。

图形摘要