title: In-situ stabilization of Pb, Zn, Cu, Cd and Ni in the multi-contaminated sediments with ferrihydrite and apatite composite additives.
abstract: Three additives were evaluated for their effectiveness in the attenuation of Pb2+, Zn2+, Cu2+, Cd2+, Ni2+ in contaminated sediments. Apatite, ferrihydrite and their composite were applied to the sediments. For the remediation, BCR, SEM/AVS and TCLP were adopted as the evaluating method and comparison of their results were used for the first time to test in-situ stabilization effect. The results showed that after 5 months composite treatment, more than 70% Pb2+, 40% Zn2+, 90% Cu2+, 50% Cd2+ and 80% Ni2+ was immobilized in oxidizable and residual phases, respectively. Compared to untreated sediment, Pb2+, Zn2+, Cu2+, Cd2+ in residual fraction increased 20%, 10%, 10%, 10% with composite treatment after 5 months, respectively. SigmaSEM/AVS ratio declined from 12.6 to 9.3, in addition, composite treatments reduced the leaching of Pb2+ and Zn2+ from 10.6 mg L(-1) and 42.5 mg L(-1) to 5.4 mg L(-1) and 24.1 mg L(-1) in the sediment by TCLP evaluation. Meanwhile, apatite and ferrihydrite composite additives lowered the bioavailability and toxicity of sediments as well. Ferrihydrite had a positive effect in controlling the bioavailability and toxicity of heavy metals because it effectively retarded the oxidation of AVS in sediment.
authors: College of Environmental Engineering, Shanghai University, Shanghai 200072, PR China. grqian@shu.edu.cn
authors: Guangren
authors: G
authors: Qian
authors: Wei
authors: W
authors: Chen
authors: Teik Thye
authors: TT
authors: Lim
authors: Pengcheong
authors: P
authors: Chui
mesh_terms: D001031:Apatites / Q000737:chemistry*; D002104:Cadmium / Q000737:chemistry; D002681:China; D003300:Copper / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D019015:Geologic Sediments / Q000032:analysis*; D007854:Lead / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry* / Q000633:toxicity; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction; D010316:Particle Size; D012995:Solubility; D013440:Sulfides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity; D014877:Water Pollution, Chemical / Q000032:analysis; D015032:Zinc / Q000737:chemistry
chemical_list: D001031:Apatites; D005290:Ferric Compounds; D019216:Metals, Heavy; D013440:Sulfides; D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead; D003300:Copper; D009532:Nickel; C092844:ferric oxyhydroxide; D015032:Zinc