电解浮选用于活性污泥固液分离的正交实验研究

Electro-flotation using in solid-liquid separation of activated sludge by orthogonal method

本研究旨在探索用电解浮选进行活性污泥固液分离的可行性。研究通过小试试验确定电解浮选进行活性污泥固液分离的适宜工艺条件,在装有Ti/RuO2-IrO2-TiO2阳极、Ti阴极的电解浮选槽中进行了活性污泥固液分离的研究,针对影响电解气浮工艺的4个主要影响因素(水力停留时间、接触室电流密度、分离区电流密度和接触室极板间距)及3个合适的水平进行正交试验。结果表明,分离区电流密度是最主要影响因素。当进水SS浓度为1687 mg/L时,在停留时间为25 m in,接触室电流密度为5 mA/cm2,分离区电流密度为4 mA/cm2,极板间距为3 mm的条件下进行电解浮选验证性试验,悬浮固体颗粒物去除率较高,去除率为98.9%,能耗0.54 kW h/m3。

This research aimed to study the feasibility of using electroflotation as a substitute for traditional dissolved air flotation to activated sludge solidliquid separation. Through bench scale the research determined the appropriate operating conditions for activated sludge solidliquid separation using electroflotation. The separation of suspended solids （SS） from activated sludge was carried out in an electro-flotation cell which has two sets of electrodes,three Ti/RuO2-IrO2-TiO2 anodes and three Ti screen cathodes. The four main parameters investigated were hydraulic retention time （HRT） , current density in contacting zone, current density in separating zone and electrode gap in contacting zone. Through the orthogonal method, we found out the best experimental condition of the removal ratio of SS and the current density in separating zone was the most important parameter. Under the conditions with initial SS about 1687 mg/L, HRT 25 min, current density 5 mA/cm^2 in contacting zone, current density 4 mA/cm^2 in separating zone, the electrode gap in contacting zone of 3 mm, the removal rate of SS can reach up to 98.9%, at this point, the electrolysis energy consumption is 0.54 kWh/m^3 wastewater.