电导率对城镇污泥电渗透脱水效果的影响

采用电渗透脱水技术对经机械脱水的城镇污泥泥饼进行深度脱水,考察了使用添加Na2SO4溶液以及使用去离子水清洗的方式改变污泥的电导率对污泥电渗透脱水效果与能耗的影响.结果表明,随着添加的Na2SO4的量的增加,污泥的电导率从1103μS/cm上升至2575μS/cm,电渗透脱水后污泥的最终含水率从51.2%降低至45.7%,脱水效果有所提高,但是由于初始阶段通过污泥泥饼的电流的增加,脱水过程中所需能耗也相应上升23.3%~69.2%.随着对污泥清洗次数的增加, 污泥的电导率从988μS/cm上升至371μS/cm,电渗透脱水后污泥的最终含水率从52.3%增加至53.1%,脱水效果有所下降,但是由于初始阶段通过污泥泥饼的电流的降低,使得所需能耗降低15%~24%.因此,对电导率较低的污泥使用电渗透脱水技术进行深度脱水,可以在保证脱水效果的情况下最大限度地降低能耗.

Effect of conductivity on the performance of electro-dewatering of municipal sludge

The performance of electro-osmotic method for dewatering municipal sludge was investig. The effect of sludge conductivity on dewatering efficiency and energy consumption was evaluated via adding Na2SO4 and washing by deionized water to adjust the conductivity. The results showed that with increase in Na2SO4 dosage, the sludge moisture decreased from 51.2% to 45.7% after 20min of electro-dewatering. However, the energy consumption increased by 23.3%~69.2% with increasing conductivity. Decreasing the sludge conductivity by deionized water washing resulted in a slight increase in the final moisture of sludge from 52.3% to 53.1% after 20 min of electro-dewatering. However, the energy consumption decreased considerably by 15%~24%. The results indicate that electro-dewatering is a suitable dewatering method for sludges of low conductivity.