Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile

• Published in: Environmental science and pollution research international 2012-05, Vol.19 (4), p.1131-1143
• Main Authors: Cárcamo, Valeska, Bustamante, Elena, Trangolao, Elizabeth, de la Fuente, Luz María, Mench, Michel, Neaman, Alexander, Ginocchio, Rosanna
• Format: Article
• Language: English
• Subjects: Acid rain; Acidic soils; Acidification; ACIDS; Aerials; Animal Shells - chemistry; Animals; Aquatic Pollution; Arsenic; Arsenic - chemistry; Atmospheric Protection/Air Quality Control/Air Pollution; Bioremediation; Biosolids; Chile; Copper; Copper - chemistry; Earth and Environmental Science; Ecotoxicology; Environment; Environment and Society; Environmental Chemistry; Environmental Health; Environmental Restoration and Remediation - methods; Environmental risk; Environmental Sciences; Flame Ionization; Heavy metals; Immobilization; Industrial Waste; Laboratories; Lolium - drug effects; Lolium - growth & development; Metals; Metals - chemistry; Mining; Neutralization; Phytotoxicity; Plant tissues; Pore water; Research Article; Sewage - chemistry; Shells; Sludge; Smelters; SMELTING; SMELTING EQUIPMENT; Soil amendment; Soil contamination; Soil Pollutants - chemistry; Soil pollution; Soil remediation; SOILS; Solubilization; Spectrophotometry, Atomic; Studies; Topsoil; Waste Water Technology; Water Management; Water Pollution Control; Zeolites; Zeolites - chemistry; Zinc
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-011-0673-3

Introduction Acidic and metal(oid)-rich topsoils resulted after 34 years of continuous operations of a copper smelter in the Puchuncaví valley, central Chile. Currently, large-scale remediation actions for simultaneous in situ immobilization of metals and As are needed to reduce environmental risks of polluted soils. Aided phytostabilization is a cost-effective alternative, but adequate local available soil amendments have to be identified and management options have to be defined. Materials and methods Efficacy of seashell grit (SG), biosolids (B), natural zeolite (Z), and iron-activated zeolite (AZ), either alone or in mixtures, was evaluated for reducing metal (Cu and Zn) and As solubilization in polluted soils under laboratory conditions. Perennial ryegrass was used to test phytotoxicity of experimental substrates. Results Soil neutralization to a pH of 6.5 with SG, with or without incorporation of AZ, significantly reduces metal (Cu and Zn) solubilization without affecting As solubilization in soil pore water; furthermore, it eliminates phytotoxicity and excessive metal(oid) accumulation in aerial plant tissues. Addition of B or Z to SG-amended soil does not further reduce metal solubilization into soil pore water, but increase As solubilization due to excessive soil neutralization (pH > 6.5); however, no significant As increase occurs in aerial plant tissues. Conclusion Simultaneous in situ immobilization of metal(oid) in acidic topsoils is possible through aided phytostabilization.