影响MFC产电能力及污水净化的非生物因素研究

Study on Effect of Abiotic Factors on Electricity-Generation and Wastewater-Treatment by Microbial Fuel Cells

以厌氧污泥接种模拟生活污水,构建双室无介体型微生物燃料电池(MFC).以输出功率密度、库仑效率和CODCr(化学需氧量)去除率为评价指标,采用正交设计考察4种非生物因素(即阴、阳极材料、底物和电子受体)对MFC产电及污水净化的影响.在此基础上进一步探讨阴极离子浓度对电能输出的影响.结果表明:对MFC产能及污水净化的影响因素顺序为:电子受体>阳极>阴极>底物,最优组合为碳毡-乳酸钠-不锈钢板-铁氰化钾+溶解氧;向阴极液中投加NaCl可使产电能力显著增强,最佳投加量为150mmol·L-1.同时,阴极室定期添加铁氰化钾可维持电流稳定.试验中,葡萄糖型、乳酸钠型以及混合型底物模拟污水的CODCr均得到有效去除,平均去除率达85.2%,显示了研究的MFC具有很强的产电和污水净化能力.

Taking anaerobic sludge as inoculant and simulated domestic wastewater as its fuel, a two-chambered microbial fuel cell （MFC） without electron mediator has been developed. Based on the evaluation indexes of output power density, coulombic efficiency and CODCr removal rate, four abiotic factors affecting MFC performance i.e. anode, cathode, substrates and electron acceptor were investigated with an orthogonal experiment （L9（34））. Meanwhile, the best ionic concentration in cathode chamber was determined. After 9 times comparing, it concluded that the impact order of factors through analyzing the value ＂R＂ was＂electron acceptoranodecathodesubstrates＂. The optimum set for MFC included carbon felt, sodium lactate, stainless steel plate, potassium ferricyanide and dissolved oxygen. Furthermore, by adding NaCl into cathode electrolyte, the electricity generation of MFC would enhanced greatly, and the optimum concentration was 150 mmol·L-1. Meanwhile, it needed to add potassium ferricyanide regularly to maintain the current stable. Especially, the COD removal rates of different simulated wastewaters, including glucose, sodium lactate and the mixed pattern were all up to 85.2%, which showed that the MFC has strong ability of electricity generation and waste water purification.