title: Assessment of natural sepiolite on cadmium stabilization, microbial communities, and enzyme activities in acidic soil.
abstract: A pot trial was conducted to assess the efficiency of sepiolite-induced cadmium (Cd) immobilization in ultisoils. Under Cd concentrations of 1.25, 2.5, and 5 mg kg(-1), the available Cd in the soil after the application of 1-10 % sepiolite decreased by a maximum of 44.4, 23.0, and 17.0 %, respectively, compared with no sepiolite treatments. The increase in the values of soil enzyme activities and microbial number proved that a certain metabolic recovery occurred after sepiolite treatment. The dry biomass of spinach (Spinacia oleracea) increased with increasing sepiolite concentration in the soil. However, the concentration (dry weight) of Cd in the spinach shoots decreased with the increase in sepiolite dose, with maximum reduction of 92.2, 90.0, and 84.9 %, respectively, compared with that of unamended soils. Under a Cd level of 1.25 mg kg(-1), the Cd concentration in the edible parts of spinach at 1 % sepiolite amendment was lower than 0.2 mg kg(-1) fresh weight, the maximum permissible concentration (MPC) of Cd in vegetable. Even at higher Cd concentrations (2.5 and 5 mg kg(-1)), safe spinach was produced when the sepiolite treatment was up to 5 %. The results showed that sepiolite-assisted remediation could potentially succeed on a field scale by decreasing Cd entry into the food chain.
authors.affiliation: Key Laboratory of Original Environmental Quality, Institute of Agro-environmental Protection, Ministry of Agriculture, Tianjin 300191, China.
authors.forename: Yuebing
authors.initials: Y
authors.lastname: Sun
authors.forename: Guohong
authors.initials: G
authors.lastname: Sun
authors.forename: Yingming
authors.initials: Y
authors.lastname: Xu
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Liang
authors.forename: Dasong
authors.initials: D
authors.lastname: Lin
authors.forename: Fazhi
authors.initials: F
authors.lastname: Hu
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D017633:Magnesium Silicates / Q000494:pharmacology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D018724:Spinacia oleracea / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D017633:Magnesium Silicates; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; C001671:magnesium trisilicate