Quantitative analysis and reduction of the eco-toxicity risk of heavy metals for the fine fraction of automobile shredder residue (ASR) using H2O2.
Automobile shredder residue (ASR) fraction (size <0.25mm) can be considered as hazardous due to presence of high concentrations of heavy metals. Hydrogen peroxide combined with nitric acid has been used for the recovery of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd and Cr) from the fine fraction of ASR. A sequential extraction procedure has also been used to determine the heavy metal speciation in the fine fraction of ASR before and after treatment. A risk analysis of the fine fraction of ASR before and after treatment was conducted to assess the bioavailability and eco-toxicity of heavy metals. These results showed that the recovery of heavy metals from ASR increased with an increase in the hydrogen peroxide concentration. A high concentration of heavy metals was found to be present in Cbio fractions (the sum of the exchangeable and carbonate fractions) in the fine fraction of ASR, indicating high toxicity risk. The Cbio rate of all selected heavy metals was found to range from 8.6% to 33.4% of the total metal content in the fine fraction of ASR. After treatment, Cbio was reduced to 0.3-3.3% of total metal upon a treatment with 2.0% hydrogen peroxide. On the basis of the risk assessment code (RAC), the environmental risk values for heavy metals in the fine fraction of ASR reflect high risk/medium risk. However, after treatment, the heavy metals would be categorized as low risk/no risk. The present study concludes that hydrogen peroxide combined with nitric acid is a promising treatment for the recovery and reduction of the eco-toxicity risk of heavy metals in ASR.
Department of Environmental Engineering, Kwangwoon University, Seoul 139-701, Republic of Korea. Electronic address: jiwansingh95@gmail.com.
Jiwan
J
Singh
Division of General Education, Kwangwoon University, Seoul 139-701, Republic of Korea.
Jae-Kyu
JK
Yang
Department of Environmental Engineering, Kwangwoon University, Seoul 139-701, Republic of Korea. Electronic address: yychang@kw.ac.kr.
Yoon-Young
YY
Chang
D001336:Automobiles; D005591:Chemical Fractionation; D054750:Ecotoxicology / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity*; D017942:Nitric Acid / Q000737:chemistry; D059027:Recycling / Q000379:methods*; D018570:Risk Assessment / Q000379:methods*
D019216:Metals, Heavy; D017942:Nitric Acid; D006861:Hydrogen Peroxide
C(bio); Eco-toxicity risk; Fine fraction of ASR; Heavy metals; RI; Speciation