title: Evaluation of silkworm excrement and mushroom dreg for the remediation of multiple heavy metal/metalloid contaminated soil using pakchoi.
abstract: The economical, environmental friendly and efficient materials to remediate the pollution with multiple heavy metals and metalloids are scarce. Silkworm excrement (SE) and mushroom dregs (MD) are two types of agricultural wastes, and they are widely used to improve the soil fertility in many regions of China. A pot experiment with sixteen treatments was set up to assess the possibility of using SE and MD to stabilize heavy metals and metalloids and reduce their uptake in pakchoi cultivated in slightly contaminated soils with arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn). The results showed that the single addition of SE obviously stimulated the growth of pakchoi, reduced the contents of all tested heavy metals and metalloids in the edible part of pakchoi and availability of Zn and Cd in soil. The single MD treatment showed an inferior ability to enhance the growth and reduce the contents of heavy metals and metalloids in the edible part of pakchoi. The combined utilization of SE and MD appeared not to show better effects than their individual treatment when using them to remediate this contaminated soil. Some potential mechanisms on the stimulation on pakchoi growth and decreasing the accumulation of heavy metals and metalloids in pakchoi subjected to SE were suggested, including: (1) enhancing soil pH to impact the availability of heavy metals and metalloids; (2) improve the fertility of soil; (3) sulfhydryl groups of organic materials in SE play a role in conjugating heavy metals and metalloids to affect their availability in soil; and (4) stimulating the growth of pakchoi so as to show a "dilution effect" of heavy metals and metalloids.
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; Innovation Team of Remediation of Heavy Metal Contaminated Farmland Soil, Chinese Academy of Agricultural Sciences, China.
authors.forename: Ruigang
authors.initials: R
authors.lastname: Wang
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; Innovation Team of Remediation of Heavy Metal Contaminated Farmland Soil, Chinese Academy of Agricultural Sciences, China.
authors.forename: Junkang
authors.initials: J
authors.lastname: Guo
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; Innovation Team of Remediation of Heavy Metal Contaminated Farmland Soil, Chinese Academy of Agricultural Sciences, China.
authors.forename: Yingming
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; Innovation Team of Remediation of Heavy Metal Contaminated Farmland Soil, Chinese Academy of Agricultural Sciences, China. Electronic address: frwzym@aliyun.com.
authors.forename: Renwei
authors.initials: R
authors.lastname: Feng
mesh_terms: D000363:Agaricales; D000383:Agriculture; D000818:Animals; D001151:Arsenic / Q000378:metabolism; D018533:Biomass; D012831:Bombyx; D002104:Cadmium / Q000378:metabolism; D002681:China; D004787:Environmental Pollution; D052918:Environmental Restoration and Remediation; D005243:Feces; D005308:Fertilizers; D007854:Lead / Q000378:metabolism; D058955:Metalloids / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000378:metabolism*; D014675:Vegetables / Q000254:growth & development / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism
chemical_list: D005308:Fertilizers; D058955:Metalloids; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D015032:Zinc; D001151:Arsenic
keywords: Mushroom dreg; Pakchoi; Pot experiment; Silkworm excrement; Soil contamination