Influence of Fenton pretreatment on heavy metal speciation and bioleaching efficiency in municipal sludge [Fenton预处理对城市污泥重金属形态及生物淋滤溶出影响]
Journal
Chinese Journal of Environmental Engineering
Journal Volume
13
Journal Issue
3
Pages
725-731
Date Issued
2019
Author(s)
Abstract
In order to improve the low dissolution efficiency of heavy metals (Cr, As and Pd) in municipal sludge by bioleaching, Fenton oxidation was used to pretreat the municipal sludge. The effects of Fenton oxidation on the species transformation of heavy metals Cr, As and Pd in the sludge and their dissolution efficiencies in subsequent bioleaching were investigated. The results showed that after the Fenton pretreatment under the conditions of pH=4.00, Fe2+=1.00 g•L-1 and H2O2=9 g•L-1, both the stable oxidized and residual species of heavy metals Cr, As and Pb partly transformed into the unstable acid extractable and reducible ones. And the ratios of unstable Cr, As and Pb species increased from 15%, 30% and 9% to 24%, 41% and 11%, respectively. The results of bioleaching experiments showed that the variations of heavy metal species led to the increase in the dissolution rates of Cr, As and Pb from 52.71%, 11.15% and 33.19% to 60.76%, 24.32% and 45.96%, respectively. Fenton pretreatment combined with bioleaching can improve the removal efficiency of Cr, As and Pb, and contribute to achieving the harmless treatment and disposal of sewage sludge. © 2019, Science Press. All right reserved.
Subjects
Bioleaching; Fenton oxidation; Heavy metals speciation; Sewage sludge
SDGs
Type
journal article