title: Stabilization/solidification of lead in MSWI fly ash with mercapto functionalized dendrimer Chelator.
abstract: This work compares the performance of stabilizing Pb by Sodium sulfide (Na2S), Sodium phosphate (Na3PO4), thiourea (H2NCSNH2), and mercapto functionalized dendrimer (TEPA-SNa) in MSWI fly ash, including leaching toxicity analysis and leaching behavior analysis, as a function of pH. The leaching toxicity in fly ash indicated that leaching value of Pb stabilized by Na2S, Na3PO4, and H2NCSNH2 has remained higher than the limit value (0.25mg/L) with a dosage of 10%. However, the leaching value associated with TEPA-SNa approaches zero at a dosage of 3%. The effective leaching test results showed the leaching amount of Pb stabilized by TEPA-SNa with a dosage of 3% to be 3.58 mg/kg less than the maximum allowable amount of leaching (5mg/kg), but the amount of Pb leached by Na2S, Na3PO4, and H2NCSNH2 was much higher than 5mg/kg. The leaching behavior of Pb as a function of pH showed that the leaching concentration of Pb stabilized by TEPA-SNa can approach zero at a dosage of 5% no matter how the pH changes. In summary, TEPA-SNa can interact with Pb(2+) in the acid-base environment and effectively immobilize Pb(2+) in fly ash in the long term.
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China. Electronic address: bingru@tongji.edu.cn.
authors.forename: Bingru
authors.initials: B
authors.lastname: Zhang
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
authors.forename: Weixiao
authors.initials: W
authors.lastname: Zhou
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
authors.forename: Huangpu
authors.initials: H
authors.lastname: Zhao
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Tian
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
authors.forename: Fengting
authors.initials: F
authors.lastname: Li
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
authors.forename: Yinan
authors.initials: Y
authors.lastname: Wu
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D060729:Coal Ash / Q000032:analysis*; D050091:Dendrimers / Q000737:chemistry*; D017745:Incineration; D007854:Lead / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D013890:Thiourea / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D060729:Coal Ash; D050091:Dendrimers; D010710:Phosphates; D013438:Sulfhydryl Compounds; D013440:Sulfides; D007854:Lead; D013890:Thiourea; C018279:sodium phosphate; C033479:sodium sulfide
keywords: Heavy metals; Leaching behavior; Leaching toxicity; MSWI fly ash; Specification distribution; Stabilization