通过考察水平电场作用下活性污泥的性质(pH、电导率)、絮凝调理及电场因素(电压大小、电场应用方式、极板间距)对污泥电脱水效果的影响,确定了水平电场下污泥电脱水的最佳条件.结果表明,对于本研究的活性污泥,以水平电场为驱动力进行脱水,在原始pH(6.93)、电导率=1.46 mS·cm-1的条件下污泥电脱水效果最好;投加阳离子型聚丙烯酰胺(CPAM)可以使污泥脱水率提高30%~40%,缩短达到相同电脱水效果的时间,但对电脱水率的提高不显著.水平电场施加60 min,絮凝调理后污泥的电脱水率可达83.12%,而对应的原始污泥则需要120 min才能达到75.31%的电脱水效果.延迟电场应用对污泥电脱水效果产生抑制作用.此外,本研究确定的最佳脱水条件为:CPAM投药量为9 g.kg-1,电场强度为600V·m-1,极板间距为40 mm,电场应用时间为60 min.在上述最佳条件下对活性污泥进行电脱水,其含水率从99.30%降至95.15%,脱水率可达85.33%.
For an electro-dewatering process of activated sludge(AS),the effect of pH and conductivity of AS,flocculation conditioning and operation factors of horizontal electric field(voltage magnitude,method of applying electric field and distance between plates) were investigated,and the corresponding optimum electro-dewatering conditions were also obtained.The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value(6.93) and conductivity(1.46 mS·cm-1).CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process,whereas a slight increase in the electro-dewatering rate.The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes,while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes.The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate.Moreover,the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g·kg-1,electric field strength of 600 V·m-1,distance between the two plates of 40 mm,dehydration time of 60 minutes.Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly.