Accumulation and chemical fractionation of Cu in a paddy soil irrigated with Cu-rich wastewater
Accumulation and chemical fractionation of Cu in a paddy soil irrigated with Cu-rich wastewater
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富铜废水灌溉水稻土中铜的富集及化学分馏
DOI：
10.1016/s0016-7061(03)00080-6
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发表时间：
2003-07-01
期刊：
影响因子：
6.1
通讯作者：
Christie, P
中科院分区：
文献类型：
--
作者：
Luo, YM;Jiang, XJ;Christie, P
研究了用富铜废水灌溉的稻田土壤中铜 (Cu) 的积累、化学分馏和稻米 (Oryza sativa) 的有效性。使用单次萃取和连续萃取对土壤样品中铜的化学成分进行分配。使用的单一提取剂溶液是水、乙酸铵和 EDTA，用于提取土壤中的水溶性、可交换性和络合铜组分。还使用三步连续萃取程序（HAOc/NH2OH.HCl/H2O2）将与土壤固体相关的铜分馏为三个部分：弱酸溶解的、可还原的铁和锰氧化物结合以及可氧化的有机物结合。残余分数计算为总（王水可提取）Cu 与三个连续分数之和之间的差值。废水灌溉后铜主要积累在土壤剖面的表层(10 cm),与同一地区未灌溉土壤(23 mg kg(-1))相比增加了近7倍(15 8 mg kg(-1)),并且在土壤表面以下的低层(10-20 cm)也显着升高。水溶性组分、可交换组分和络合组分中Cu的浓度分别从未污染土壤中的0.02、0.33和14.1 mg kg(-1)增加到污染土壤中的0.12、6.30和98.0 mg kg(-1)。灌溉还导致弱酸溶性、可还原的铁和锰氧化物结合、可氧化的有机物结合以及铜的残留部分显着增加。污染水稻土中，可还原的Fe、Mn氧化物结合部分最大（占总Cu的36%），其次是可氧化部分，最后是残余部分，最小的是乙酸可溶部分。然而，在未污染的土壤中，总铜的 53% 存在于残余部分中，其次是可还原的铁和锰氧化物结合部分（总铜的 22%）。生物可利用部分中Cu的积累导致重度污染(HP)土壤中水稻植株中的Cu浓度比未污染土壤增加了三倍(高达38 mg kg(-1))。由于铜毒性，植物产量大幅下降。数据表明，在水稻土中，可还原的铁和锰氧化物结合部分对于控制铜的移动性和生物利用度可能比可氧化有机物结合部分更重要。 (C) 2003 年由 Elsevier Science B.V. 出版
The accumulation, chemical fractionation and availability of copper (Cu) to rice (Oryza sativa) in a paddy soil previously irrigated with Cu-enriched wastewater were investigated. Chemical fractions of Cu in soil samples were partitioned using single and sequential extractions. The single extractant solutions used were water, ammonium acetate and EDTA for extraction of water-soluble, exchangeable and complexed Cu fractions in the soil. A three-step sequential extraction procedure (HAOc/NH2OH.HCl/H2O2) was also used to fractionate Cu associated with soil solids into three fractions: weak acid-soluble, reducible Fe and Mn oxides bound and oxidisable organic matter bound. The residual fraction was calculated as the difference between total (aqua regia extractable) Cu and the sum of the three sequential fractions. Copper accumulated mainly in the top layer (10 cm) of the soil profile after wastewater irrigation, increased almost seven-fold (15 8 mg kg(-1)) compared with non-irrigated soil (23 mg kg(-1)) from the same area, and was also elevated significantly in low layer (10-20 cm) below the soil surface. Concentrations of Cu in the water-soluble, exchangeable and complexed fractions increased from 0.02, 0.33 and 14.1 mg kg(-1), respectively, in unpolluted soil to 0.12, 6.30 and 98.0 mg kg(-1) in polluted soil. Irrigation also led to marked increases in the weak acid-soluble, reducible Fe and Mn oxide bound, oxidisable organic matter bound and residual fractions of Cu. In the contaminated paddy soil, the reducible Fe and Mn oxide bound fraction was the largest (36% of total Cu), followed by the oxidisable fraction, then the residual fraction, and the smallest was the acetic acid-soluble fraction. However, in the unpolluted soil, 53% of total Cu was present in the residual fraction followed by the reducible Fe and Mn oxide bound fraction (22% of total Cu). Accumulation of Cu in the bioavailable fractions resulted in a three-fold increase in Cu concentration (up to 38 mg kg(-1)) in rice plants in the heavily polluted (HP) soil compared with unpolluted soil. Plant yields decreased substantially due to Cu toxicity. Data indicate that the reducible Fe and Mn oxide bound fraction may be more important for controlling the mobility and bioavailability of Cu than the oxidisable organic matter bound fraction in paddy soils. (C) 2003 Published by Elsevier Science B.V.