Enhanced electrokinetic remediation removal heavy metal from sludge assisted by the combined biodegradable iminodisuccinic acid and electrolyte circulation technology

Heavy metal severely restricted the sludge agricultural use. Therefore, it is imperative to seek a novel and proficient method removal heavy metal from sludge. In this study, it proposed that a coupled with biodegradable chelating ligand iminodisuccinic acid and electrolyte circulation technology, which was used to enhance electrokinetic (EK) remediation removing heavy metal from the sludge. Electrical current, electrical conductivity and electrolyte pH, electrical conductivity and sludge pH, the toxic metal concentration with different time and remediation room section were evaluated in this work. Results demonstrated the combined iminodisuccinic acid and electrolyte circulation technology could enhance electrokinetic remediation removal toxic metal from sludge. Also, it can increase the cation and anion dissolution and electric current, and the cathode obtained a higher electrical conductivity of electrolyte and sludge than anode, and maintained a low pH of catholyte and sludge, the enhanced electrokinetic treatments obtained a higher removal efficiency than unenhanced electrokinetic remediation treatment, and the coupled with iminodisuccinic acid and electrolyte circulation enhanced electrokinetic treatment achieved the highest toxic metal extraction efficiency, Cu, Zn, Cr, Pb, Ni and Mn removal efficiencies were 55.0 +/- 3.78%, 66.8 +/- 2.23%, 64.6 +/- 3.87%, 49.3 +/- 3.25%, 61.6 +/- 4.22% and 57.2 +/- 2.67%, respectively, which indicated that iminodisuccinic acid and electrolyte circulation technology can effectively enhance EK remediation removal heavy metals from sludge.