title: Changes in speciation and leaching behaviors of heavy metals in dredged sediment solidified/stabilized with various materials.
abstract: Solidification/stabilization (S/S) of sediments is frequently used to treat contaminants in dredged sediments. In this study, sediment collected from the Pearl River Delta (China) was solidified/stabilized with three different kinds of functional materials: cement, lime and bentonite. Lime primarily acted via induced increases in pH, while cements stabilization occurred through their silicate-based systems and the main function of bentonite was adsorption. The speciation and leaching behaviors of specific heavy metals before and after S/S were analyzed and the results showed that the residual speciation of Cd, Cr, Ni, Pb and Zn increased in all treatments except for Cu, as the exchangeable speciation, carbonate-bound speciation and Fe-Mn-oxide-bound speciation of Cu (all of which could be stabilized) were less than 2 % of the total amount. Pb leaching only decreased when pH increased, while the mobility of Cr and Ni only decreased in response to the silicate-based systems. The leached portion of the Fe-Mn-oxide-bound speciation followed the order Zn > Cu > Ni/Cd > Pb > Cr. The leached portion of organic-matter-bound species was less than 4 % for Cd, Cr, Ni and Pb, but 35.1 % and 20.6 % for Cu and Zn, respectively.
authors: College of Environment, Hohai University, No. 1 Xikang Road, Nanjing, 210098, People's Republic of China.|Nanjing Hohai Technology Co., Ltd., Nanjing, 210098, People's Republic of China.
authors: Jianping
authors: J
authors: Bao
authors: South China Sea Institute of Plannning and Environmental Research, State Oceanic Administration, Guangzhou, 510300, People's Republic of China.
authors: Liang
authors: L
authors: Wang
authors: Australian Rivers Institute, Griffith University, Nathan, Queensland, 4111, Australia. xiao_man1989@163.com.
authors: Man
authors: M
authors: Xiao
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D002681:China; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D017610:Calcium Compounds; D019216:Metals, Heavy; D010087:Oxides; D014874:Water Pollutants, Chemical; C016538:lime
keywords: Dredged sediment; Heavy metals; Leaching behavior; Solidification/stabilization (S/S); Speciation