[Effects of Two Amendments on Remedying Garden Soil Complexly Contaminated with Pb, Cd and As]

This paper studied the effects of two amendments (iron sulfate[Fe₂ (SO₄)₃] and calcium carbonate[CaCO₃]) on the bioavailability of Pb, Cd and As in a garden soil and on the migration and accumulation of Pb, Cd and As in pepper through an in-situ experiment planting pepper plants. The results indicated that:①Addition of these amendments significantly decreased TCLP extractable contents of Pb and Cd in soil, and increased TCLP extractable contents of As.②Compared with the control group, addition of Fe₂ (SO₄)₃ led to reduction in contents of Pb and Cd in pepper fruits by 7.2%-22.9% and 2.3%-2.9%, respectively, but no obvious changes were observed for As contents in pepper fruits. Meanwhile, addition of CaCO₃ decreased the contents of Pb, Cd and As in pepper fruits by 15.8%-16.3%, 11.8%-15.0%, and 0.03%-53.2%, respectively. ③The maximum reductions for the translocation factors of Pb, Cd and As from stem to fruits in pepper plants were 16.7%, 68.0%, 10.2%, respectively, due to Fe₂(SO₄)₃ application and 16.7%, 51.5%, 45.6%, respectively, due to CaCO₃ application, compared with the control group. It was obvious that Fe₂ (SO₄)₃ and CaCO₃ could both effectively decrease the migration of soil Pb, Cd and As to pepper plants, but the effects of CaCO₃ were better than those of Fe₂ (SO₄)₃.