title: Immobilization and phytotoxicity of Pb in contaminated soil amended with γ-polyglutamic acid, phosphate rock, and γ-polyglutamic acid-activated phosphate rock.
abstract: Pot experiments were conducted to investigate the effects of γ-polyglutamic acid (γ-PGA), phosphate rock (PR), and γ-PGA-activated PR (γ-PGA-PR) on the immobilization and phytotoxicity of Pb in a contaminated soil. The proportion of residual Pb (Re-Pb) in soil was reduced by the addition of γ-PGA but was increased by the application of PR and γ-PGA-PR. The addition of γ-PGA in soil improved the accumulation of Pb in pak choi and decreased the growth of pak choi, suggesting the intensification of Pb phytotoxicity to pak choi. However, opposite effects of PR and γ-PGA-PR on the phytotoxicity of Pb to pak choi in soil were observed. Moreover, in the examined range, γ-PGA-PR activated by a higher amount of γ-PGA resulted in a greater proportion of Re-Pb in soil and weaker phytotoxicity of Pb to pak choi. The predominance of γ-PGA-PR in relieving the phytotoxicity of Pb was ascribed mainly to the increase of soil pH and available phosphate after the amendment, which could facilitate the precipitation of Pb in soil and provide pak choi with more phosphorus nutrient.
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Cai
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Su
authors.forename: Qingling
authors.initials: Q
authors.lastname: Fu
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Liu
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
authors.forename: Antonio
authors.initials: A
authors.lastname: Violante
authors.forename: Hongqing
authors.initials: H
authors.lastname: Hu
mesh_terms: D001937:Brassica / Q000187:drug effects* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D010710:Phosphates / Q000737:chemistry*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry / Q000633:toxicity
chemical_list: D010710:Phosphates; D012987:Soil; D012989:Soil Pollutants; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D007854:Lead