电絮凝法调理剩余污泥CST的影响因素分析

Influencing Factors Analysis of CST Conditioning of Surplus Sludge by Electric Flocculation

剩余污泥的减量化是污泥处理处置的难点。本文分别选用Al电极和Fe电极,以毛细吸水时间(CST)为指标,研究了极板间距、电解质种类、电压等因素对电絮凝调理剩余污泥的影响。结果表明,在处理污泥时,电絮凝通过氧化作用和絮凝作用来调理污泥,从而降低CST。极板间距较大时,电场强度较弱,不利于污泥的破解。Na Cl和Na_(2)SO_(4)对CST的影响不大,但Na OH会使溶液呈碱性,从而抑制污泥的调理。加大电压有利于降低CST。相比于Fe电极,Al电极对剩余污泥具有更佳的电絮凝调理性能。在电压15 V、极板间距3 cm、投加NaCl(0.1 g·L^(-1))的条件下,Al电极电絮凝处理剩余污泥60min时的效果最佳,CST下降了57%。

The reduction of surplus sludge was the difficult for its treatment and disposal.The effects of electrode spacing,electrolyte type and voltage on the sludge conditioning by electrocoagulation were studied by using Al electrode and Fe electrode respectively with using capillary suction time(CST)to quantify the sludge dewaterability.The results showed that the electrocoagulation could regulate the sludge through oxidation and flocculation with reducing CST.It was not conducive to sludge cracking when the electric field intensity was weak by increasing the plate spacing.The electrolytes such as NaCl and Na_(2)SO_(4) had little effect on CST,while NaOH inhibited the sludge conditioning as the solution becoming alkaline.Increasing voltage was beneficial to decrease CST.Al electrode had a higher performance than Fe electrode on the sludge conditioning.Under the conditions of 15V voltage,3cm of electrode spacing and NaCl(0.1 g/L),Al electrode showed the best performance for the sludge conditioning by electrocoagulation in 60 min.CST was cut by 57%.