Wong Jonathan W C, Wong Winnie W Y, Wei Zhenggui, Jagadeesan Hema
Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, PR China.
Sci Total Environ. 2004 May 25;324(1-3):235-46. doi: 10.1016/j.scitotenv.2003.11.001.
A greenhouse experiment was conducted to investigate the growth of Brassica juncea and Cd phytoextraction in a mimicked Cd contaminated acidic loamy soil amended with alkaline biosolids, prepared from sewage sludge and coal fly ash, in the presence and absence of EDTA at 2 mmol kg(-1). The acidic loamy soil was spiked with 0, 5, 20, 50 and 100 mg Cd kg(-1) in the form of CdCO(3) and then amended with 4% alkaline biosolids (w/w). Alkaline biosolids and 0.12% CaCO(3) amendments resulted in a higher biomass than unamended soil spiked with 20 mg kg(-1) Cd where plants did not survive and of the two amendments, alkaline biosolids amendment had higher plant dry weight yield and phytoextraction of Cd. Adding 2 mmol kg(-1) EDTA to alkaline biosolids amended soil significantly increased the solubility of Cd ions by 9- to 29-fold, but plant Cd accumulation decreased by a factor of 24-48%. The results indicate that alkaline biosolids amendment is an effective approach for assisting growth of B. juncea and phytoextraction of Cd from the contaminated acidic loamy soil, but further application of chelating agents did not enhance the phytoextraction efficiency of Cd.
进行了一项温室试验，以研究在模拟的镉污染酸性壤质土中芥菜的生长情况以及镉的植物提取效果。该酸性壤质土用由污水污泥和粉煤灰制备的碱性生物固体进行改良，试验在添加和不添加2 mmol kg(-1)乙二胺四乙酸（EDTA）的情况下进行。酸性壤质土以碳酸镉的形式添加0、5、20、50和100 mg Cd kg(-1)的镉，然后用4%（重量/重量）的碱性生物固体进行改良。碱性生物固体和0.12%碳酸钙改良剂处理后的生物量高于添加20 mg kg(-1)镉但未改良的土壤（该处理中植物无法存活），并且在这两种改良剂中，碱性生物固体改良剂的植物干重产量和镉的植物提取量更高。向碱性生物固体改良的土壤中添加2 mmol kg(-1)的EDTA可使镉离子的溶解度显著提高9至29倍，但植物对镉的积累量却降低了24%至48%。结果表明，碱性生物固体改良是促进芥菜生长以及从受污染酸性壤质土中提取镉的有效方法，但进一步施用螯合剂并不会提高镉的植物提取效率。
