Enhanced phosphorus availability and heavy metal removal by chlorination during sewage sludge pyrolysis

Xia，Yunxue1,2; Tang，Yuanyuan1; Shih，Kaimin2; Li，Bang1

2020-01-15

10.1016/j.jhazmat.2019.121110

JOURNAL OF HAZARDOUS MATERIALS   影响因子和分区

0304-3894

1873-3336

Increasing attention has been paid on the application of sewage sludge-derived biochar as soil amendments, but is always limited by heavy metals. This study conducted experiments on heavy metal removal by adding chlorinating agents (PVC, NaCl, MgCl, CaCl) during sludge pyrolysis. The chlorides addition can largely remove heavy metals by achieving the highest removal efficiency with dosage of 80 g(Cl)/kg(dry sludge) at 700 °C. The most effective removal effect was observed for Zn, Mn, Cu and Pb, with removal efficiency from 37.44% to 99.45%, 5.24% to 93.64%, 9.11% to 86.15% and 16.57% to 90.75%, respectively for the sludge before and after chlorination. Furthermore, the P-solubility in neutral ammonium citrate (P) was enhanced after chlorination and the maximum P-solubility can be obtained at 700 °C for each series. After 700 °C pyrolysis, the P-solubility was significantly increased from 40.08% of the sludge biochar to 72.07%, 74.05%, 74.00% and 76.57% of the biochar obtained after adding PVC, NaCl, CaCl, and MgCl, respectively. The highest P-solubility was observed in samples with MgCl due to the formation of Mg(PO). This study proposed a novel method to use the sludge biochar as potential P-fertilizer with effective heavy metal removal, finally achieving a “waste-to-resource” strategy for integrated management of sewage sludge.

Chlorination Heavy metal removal Phosphorus availability Pyrolysis Sludge biochar

SCI ; EI

英语

第一 ; 通讯

National Natural Science Foundation of China[21707063]

Engineering ; Environmental Sciences & Ecology

Engineering, Environmental ; Environmental Sciences

WOS:000501387100085

ELSEVIER

20193707421866

Chlorination ; Efficiency ; Heavy metals ; Magnesium compounds ; Pyrolysis ; Sewage sludge ; Sodium chloride ; Soils ; Solubility ; Waste management

Sewage Treatment:452.2 ; Soils and Soil Mechanics:483.1 ; Metallurgy and Metallography:531 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Production Engineering:913.1

ENGINEERING

2-s2.0-85071950970

Scopus

1.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution ControlSchool of Environmental Science and EngineeringSouthern University of Science and Technology,Shenzhen,1088 Xueyuan Blvd, Nanshan District,518055,China
2.Department of Civil EngineeringFaculty of EngineeringThe University of Hong Kong,Hong Kong

Xia，Yunxue,Tang，Yuanyuan,Shih，Kaimin,et al. Enhanced phosphorus availability and heavy metal removal by chlorination during sewage sludge pyrolysis[J]. JOURNAL OF HAZARDOUS MATERIALS,2020,382.

Xia，Yunxue,Tang，Yuanyuan,Shih，Kaimin,&Li，Bang.(2020).Enhanced phosphorus availability and heavy metal removal by chlorination during sewage sludge pyrolysis.JOURNAL OF HAZARDOUS MATERIALS,382.

Xia，Yunxue,et al."Enhanced phosphorus availability and heavy metal removal by chlorination during sewage sludge pyrolysis".JOURNAL OF HAZARDOUS MATERIALS 382(2020).