Dept. of Building, Civil and Environmental Eng., Concordia University, Montreal, Quebec, Canada.
Water Res. 2013 Feb 1;47(2):903-10. doi: 10.1016/j.watres.2012.11.020. Epub 2012 Nov 23.
This study investigated the impact of direct current (DC) field on the activated sludge properties for potential improvement of the biological as well as membrane treatment processes. Three mixed-liquor suspended solids (MLSS) concentrations (5,000, 10,000 and 15,000 mg/l) were subjected to current densities (CD) ranging from 5 to 50 A/m² at five electrical exposure modes (time-ON/time-OFF). The results showed that CD between 15 and 35 A/m² increased the filterability of the sludge more than 200 times when compared with the untreated reference sludge. The average removals of protein, polysaccharides and organic colloids from the sludge supernatant at this range of CD were 43%, 73% and 91%, respectively, while the average reduction of the specific resistance to filtration (SRF) was 4.8 times higher. The changes of sludge properties depended on the current density, electrical exposure mode and the MLSS concentration. At CD of 25 A/m² and MLSS below 10,000 mg/l, shorter time-OFF was needed in each electrical cycle, while more time-OFF was needed at higher MLSS concentrations. It was concluded that proper application of the DC field could improve biomass in terms of its dewaterability and the removal of SMP, which are highly correlated to membrane fouling in the submerged membrane electro-bioreactor (SMEBR).
本研究探讨了直流（DC）场对活性污泥性质的影响，以期改善生物和膜处理过程。三种混合液悬浮固体（MLSS）浓度（5000、10000 和 15000mg/L）在五个电流施加模式（通电时间/断电时间）下经受了从 5 到 50A/m² 的电流密度（CD）。结果表明，与未经处理的对照污泥相比，当 CD 在 15 到 35A/m² 之间时，污泥的过滤性能提高了 200 多倍。在这个 CD 范围内，从污泥上清液中去除蛋白质、多糖和有机胶体的平均去除率分别为 43%、73%和 91%，而比过滤阻力（SRF）的平均降低了 4.8 倍。污泥性质的变化取决于电流密度、电流施加模式和 MLSS 浓度。在 CD 为 25A/m² 和 MLSS 低于 10000mg/L 时，每个电循环需要较短的断电时间，而在较高的 MLSS 浓度下需要更多的断电时间。研究结论认为，适当应用直流场可以改善生物量的脱水性能和 SMP 的去除率，这与浸没式膜电生物反应器（SMEBR）中的膜污染密切相关。
