title: Effect of o-phenylenediamine on Cu adsorption and desorption in red soil and its uptake by paddy rice (Oryza sativa).
abstract: A study was carried out of Cu adsorption and desorption processes in red soil as affected by o-phenylenediamine (o-PD) in the range 0-80 mg/l. The results indicated that the presence of o-PD enhanced Cu adsorption in red soil in weakly acid media, meanwhile, desorption percentage of Cu from soil, extracted by 1.0 M MgCl(2), also increased when Cu adsorption in soil occurred in the presence of o-PD. The response of paddy rice to Cu in red soil shows that Cu toxicity was mitigated in the presence of o-PD and that the Cu concentration in rice straw decreased with increasing concentration of o-PD from 0 to 4.0 mmol/kg in soil. The fractions of background Cu in soil did not change noticeably in the presence of o-PD, whereas the effect of o-PD on the fractions of added Cu was significant. It was found that the exchangeable and carbonate bound Cu fractions decreased and the fraction of Cu bound to Fe-Mn oxides and organic matter increased with increasing o-PD concentration in soil when Cu was added at the same rate. Copper concentration in rice straw was significantly correlated with exchangeable Cu (r=0.961) and carbonate bound Cu (r=0.959) in soil. This result implicates that the behavior of Cu in soil is likely to be affected by organic pollutants containing amino groups.
authors.affiliation: Laboratory of Material Cycling in Pedosphere, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China.
authors.forename: Shen-Qiang
authors.initials: SQ
authors.lastname: Wang
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Zhou
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Wang
authors.forename: Huai-Man
authors.initials: HM
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000187:drug effects* / Q000378:metabolism; D010655:Phenylenediamines / Q000494:pharmacology*; D012987:Soil / Q000032:analysis*
chemical_list: D010655:Phenylenediamines; D012987:Soil; D003300:Copper; C034193:1,2-diaminobenzene