title: Co-contamination of Cu and Cd in paddy fields: Using periphyton to entrap heavy metals.
abstract: The ubiquitous native periphyton was used to entrap Cu and Cd from paddy fields. Results showed that Cu- and Cd-hydrate species such as CuOH(+), Cu2(OH)2(2+), CdOH(+), and Cu3(OH)4(2+) decreased with time in the presence of periphyton. When the initial concentrations of Cu and Cd were 10mg/L, the heavy metal content in the periphyton fluctuated from 145.20mg/kg to 342.42 mg/kg for Cu and from 101.75 mg/kg to 236.29 mg/kg for Cd after 2h exposure. The concentration of Cd in periphytic cells varied from 42.93 mg/kg to 174 mg/kg after 2h. The dominant periphyton microorganism species shifted from photoautotrophs to heterotrophs during the exposure of periphyton to Cu and Cd co-contamination. Although Cu and Cd could inhibit periphyton photosynthesis and carbon utilization, the periphyton was able to adapt to the test conditions. Cu and Cd accumulation in rice markedly decreased in the presence of periphyton while the number of rice seeds germinating was higher in the periphyton treatments. These results suggest that the inclusion of native periphyton in paddy fields provides a promising buffer to minimize the effects of Cu and Cd pollution on rice growth and food safety.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jiali
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002, China.
authors.forename: Cilai
authors.initials: C
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China; School of Civil Engineering, East China Jiaotong University, 808 Shuang Gang East Road, Nanchang, Jiangxi 330013, China.
authors.forename: Fengwu
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China. Electronic address: yhwu@issas.ac.cn.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000737:chemistry / Q000633:toxicity; D000460:Chlorophyta / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D003300:Copper / Q000737:chemistry / Q000633:toxicity; D000458:Cyanobacteria / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D005506:Food Contamination / Q000517:prevention & control; D018525:Germination / Q000187:drug effects; D012275:Oryza / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D000459:Phaeophyceae / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D003300:Copper
keywords: Cadmium; Co-contamination; Copper; Paddy field; Periphyton