生物降解高分子缓释肥在多金属污染土壤中的固定化研究

Immobilization of Cu,Zn,Cd and Pb in a multi-metal contaminated soil using biodegradable slow-release polymeric fertilizer

通过番茄盆栽试验研究了含有营养元素氮磷钾的生物降解高分子缓释肥(SRPFNPK)和具有吸水功能的生物降解高分子缓释肥(SRPFWA)对弱碱性多金属污染土壤植株稳定性的影响。结果表明,两种缓释肥处理后的土壤,养分含量、有机质含量、酶活性比空白对照土壤显著增加,土壤中Cu、Zn、Cd、Pb的有效态含量分别比空白对照土壤降低92.32%～99.10%、81.15%～96.06%、53.95%～78.51%、94.27%～99.05%;相关分析显示土壤有效磷含量、有机质含量与Cu、Zn、Cd、Pb的有效态含量呈负相关关系。与空白对照土壤相比,番茄产量显著增加,且重金属在番茄各组织内的累积量显著降低,其中果实中Cu、Cd的含量均低于食品安全标准和食品污染物限量标准。

Pot experiments were conducted to study the effects of a biodegradable slow-release polymeric fertilizer containing nutrient elements NPK（SRPFNPK） and a biodegradable slow—release polymeric fertilizer with the function of water absorption（SRPFWA） on the phytoavailibility of Cu,Zn,Cd and Pb in the multi-metal contaminated weak alkaline soils. The results showed that nutrient content,organic matter content and enzyme activity of soils significantly increased,however,phytoavailability of Cu,Zn,Cd and Pb in soils treated with SRPFNPK and SRPFWA reduced by 92.32%-99.10%,81.15%-96.06%,53.95%-78.51% and 94.27%-99.05% respectively.Correlation analysis showed that the soil available phosphorus（AP）,organic matter contents（OM） were negatively correlated with the amount of Cu,Zn,Cd and Pb available in soils. Furthermore,tomatoes on the soils treated with SRPFNPK and SRPFWA resulted in higher total marketable yields but less accumulation of heavy metals in various tissues of tomatoes. The contents of Cu and Cd in the fruits were significantly lower than the food safety standards and the maximum allowable amounts of contaminants in foods.