污泥堆肥对黄土-小麦系统中镉生物有效性的影响  

Effect of Sludge Compost on Cd Bioavailability in Loess–Wheat System

作　　者：高卓 李舒琦 武文飞[1] 王厚成[1] 胡亚虎[1] 南忠仁[1] GAO Zhuo;LI Shuqi;WU Wenfei;WANG Houeheng;HU Yahu;NAN Zhongren(College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学资源环境学院,兰州730000

出　　处：《土壤》2018年第4期746-754,共9页Soils

基　　金：国家自然科学基金项目(NSFC51178209;NSFC91025015);兰州大学中央高校基本科研业务费专项资金项目(lzujbky-2014-279;lzujbky-2014-208;lzujbky-2016-261)资助

摘　　要：将城市污泥施加于干旱区黄土中,进行小麦盆栽试验,用Tessier连续提取法对土壤镉(Cd)的形态分布进行分析,同时研究了污泥堆肥对小麦各部位Cd含量及Cd赋存形态的影响。主要得到以下结论:随Cd胁迫水平的升高,不施加污泥的对照中小麦各部位生物量无显著变化,而施加污泥的处理下的小麦根、茎叶、颖壳及籽粒均表现出生物量先增大后减小的趋势。施加不同配比污泥的土壤中,小麦各部位Cd含量均随Cd胁迫浓度的升高而升高,各部位相较,根>茎叶>壳>籽粒;随着Cd处理水平的增大,Cd活性增强,对作物的潜在危害增大;施加污泥后残渣态和有机结合态的分配系数显著增高,碳酸盐结合态降低,污泥的施用增加了不可利用态Cd的含量;无论施加污泥与否,Cd的总再分配系数均随着Cd胁迫水平的增加呈递增趋势,而结合强度系数呈递减趋势;施加污泥后Cd的总分配系数变小,结合强度系数变大,说明施加污泥降低了Cd的活性。施加污泥处理下,小麦各部位对Cd吸收的主要贡献形态为可交换态。A wheat pot experiment was conducted in arid-area loess amended with urban sludge compost, Tessier sequential extraction procedure was used to analyze Cd species distributions in soil, and the effects of sludge compost on Cd contents in different wheat organs and on Cd species in loess-wheat system were studied. The results showed that no significant difference occurred in wheat biomass of the control （without sludge compost）, while biomass of wheat roots, stems and leaves, shells and grains increased firstly and then decreased with the increase of Cd-stress level in the sludge compost treatments. Cd contents increased in all wheat organs with the increase of Cd-stress level and in an order of root 〉 stem and leaf 〉 shell 〉 grains. Cd bioavailability increased and Cd potential hazard to wheat system aggravated with the increase of Cd-stress level. The partition coefficients of organic-and residual-Cd increased significantly while that of carbonate Cd decreased, and sludge compost increased the unavailable Cd form. The total redistribution coefficients of Cd in soil with or without sludge compost increased with the increase of Cd-stress level, while bond strength coefficient of Cd increased. Sludge compost decreased total redistribution coefficient of Cd while increased bonding strength coefficient of Cd, which suggest that sludge compost inhibited Cd activity in soil. The exchangeable Cd contributed most to Cd contents in all wheat organs.

关 键 词：重金属 形态 堆肥 小麦 有效性 

分 类 号：X171.5[环境科学与工程—环境科学]