三聚磷酸钠与柠檬酸复合强化蜈蚣草修复砷污染土壤

为研究化学活化剂三聚磷酸钠和柠檬酸配合施用对蜈蚣草萃取砷效率的影响，通过模拟实验，在含砷57.7 mg·kg^-1的水稻土中，探究了单一活化剂（三聚磷酸钠0.75 g·kg^-1土，柠檬酸0.75 g·kg^-1土）和三聚磷酸钠与柠檬酸配合施用（三聚磷酸钠：柠檬酸=0.375 g·kg^-1土：0.375 g·kg^-1土）对土壤有效态砷含量变化的影响；采用盆栽实验，探究了三聚磷酸钠和柠檬酸配合施用（三聚磷酸钠：柠檬酸=0.187 5 g·kg^-1土：0.187 5 g·kg^-1土）对蜈蚣草地上部萃取土壤砷的影响。模拟实验结果表明，与单一活化剂相比，三聚磷酸钠和柠檬酸配合施用对土壤砷的活化效果更显著。盆栽实验结果表明：与对照组相比，三聚磷酸钠和柠檬酸配合施用可使蜈蚣草羽叶干质量提高21.8%以上，砷萃取总量提高40.4%以上；根际土总砷含量下降，土壤脲酶和脱氢酶活性显著增加。研究表明在砷污染土壤施加三聚磷酸钠和柠檬酸，由于其提高了蜈蚣草植物干质量和土壤有效态砷含量，羽叶萃取砷效率明显提高。

Effect of a sodium tripolyphosphate and citric acid composite on arsenic bioaccumulation caused by arseniccontaminated soil in Pteris vittata L.

To study the effect of a sodium tripolyphosphate and citric acid composite on arsenic bioaccumulation caused by As-contaminated soil in Pteris vittata L., the effect of sodium tripolyphosphate (0.75 g·kg^-1 soil), citric acid (0.75 g·kg^-1 soil), and the sodium tripolyphosphate and citric acid composite (0.375 g·kg^-1 soil sodium tripolyphosphate and 0.375 g·kg^-1 soil citric acid) on the content of available As was studied using a soil screening experiment in paddy soil containing 57.7 mg·kg^-1 As. The effect of the composite (0.187 5 g·kg^-1 soil sodium tripolyphosphate and 0.187 5 g·kg^-1 soil citric acid) on As bioaccumulation in Pteris vittata L. was studied using a pot experiment in paddy soil. The results showed that the activation effect of the composite on soil As was more significant than that of a single chemical activator. Furthermore, compared with the control, the dry weight of pinnae and the total amount of As extraction increased by more than 21.8% and 40.4%, respectively, by the application of the composite. Additionally, in the rhizosphere soil of the pot experiment, the total As content decreased and the activities of urease and dehydrogenase increased significantly compared with those for the control. These results suggest that the effect of As bioaccumulation caused by As-contaminated soil on Pteris vittata L. increases significantly by the application of the composite. The increase was mainly caused by the increase in plant dry weight and the As content available in the soil.