MA Cai-xia,LIU Lei,LI Bi-qing,et al.Effect of Enhanced Chemical Leaching on Heavy Metal Dissolution and Phosphorus Release from Sludge[J].China Water & Wastewater,2021,37(5 5):66-70.
Click Copy

Effect of Enhanced Chemical Leaching on Heavy Metal Dissolution and Phosphorus Release from Sludge

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第37卷 Number: 5 5 Page: 66-70 Column: Date of publication: 2021-03-01
Author(s):
MA Cai-xia1; 2; LIU Lei3; LI Bi-qing4; LI Peng-fei4; XIAO Yu-tang1; 2; ZHANG Li-guo1; 2
(1. Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University, Guangzhou 510006， China; 2. Key Laboratory of Theoretical Chemistry of Environment ， School of Environment, South China Normal University, Guangzhou 510006， China; 3. School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808， China; 4. Guangzhou Sewage Purification Co. Ltd.， Guangzhou 510163， China)
Keywords:
sludge; dissolution of heavy metals; phosphorus release; dewaterability
Abstract:
In order to solve the problem of low dissolution rate of heavy metals when using traditional chemical leaching method to treat sewage sludge, contrastive tests of two enhanced chemical leaching methods were designed, and effects of enhanced chemical leaching on comprehensive properties of the treated sludge were explored through determination of heavy metal speciation distribution, sludge organic matters and phosphorus release and sludge solids content. The combined treatment of dilute sulfuric acid and ferric chloride (method 1) had no obvious effect on Cu and Cr dissolution, however, the addition of NaNO2 (method 2) could enhance the Cu dissolution rate from 7% to 82% and the Zn dissolution rate from 79% to 88%. Meanwhile, both methods increased the release of organic matters and phosphorus in sludge, and the phosphorus contents decreased from 23.2 mg/g to 12.3 mg/g and 10.7 mg/g, respectively. Compared with the raw sludge, dewaterability of the enhanced leaching sludge was also improved obviously, and solid contents of the sludge increased by 52% and 61%, respectively.
Last Update: 2021-03-01