皇竹草对酸与Cd污染农田土壤的治理效果及安全应用分析

在大田条件下,研究了在酸与Cd污染农田土壤中种植皇竹草对污染农田的治理效果和应用安全性。结果表明,在各土壤处理中,对照处理(不施用土壤添加剂)的皇竹草中Cd含量最高,为1.69 mg·kg~(-1)(干重),富集系数大于1,表现出一定的Cd富集特性。对照处理的皇竹草对Cd的提取量、提取效率分别为119.91 g·hm~(-2)、6.98%,修复效果优于在同等条件下种植的Cd超富集植物龙葵,若将试验区的土壤Cd修复到《土壤环境质量标准》(GB 15618—1995)的二级标准限值以内,经计算约需9年。皇竹草既可以提取土壤中的Cd,同时还可作为饲用牧草、还田肥料、造纸原料、能源植物等进行安全利用。因此,皇竹草是治理修复及综合利用酸与Cd污染农田的可行性植物材料。

Phytoremediation efficiency of Pennisetum hydridum for acid-and cadmium-polluted soil and its safe utilization

Under field conditions, phytoremediation of acid- and cadmium- polluted soil by and its application safety were studied. Pen-nisetum hydridum exhibited Cd-enrichment capacity, as indicated by its enrichment coefficient of greater than 1. Under different soil treat-ments, Cd content, extraction quantity and efficiency of P.hydridum were the highest in the control, which was up to 1.69 mg·kg-1(dry weigh), 119.91 g·hm-2 and 6.98%, respectively. This indicated that phytoremediation efficiency of P. hydridum was better than that of Solanumnigrum, a known Cd hyperaccumulator. Calculation showed that it would take only 9 years for P. hydridum to remedy Cd polluted soil in the experimental area by reducing soil Cd below the limit of the grade II of "Environmental Quality Standards for Soils"(GB 15618—1995). In addition to soil remediation, P. hydridum also has wide scope of applications, such as forage grass, organic fertilizer, paper-making material, energy plant, etc. Pennisetum hydridum would therefore be a feasible plant for phytoremediation of acid- and Cd-polluted farmland and safe utilization.