PAM与粉煤灰改良沙土中重金属的迁移和富集规律

探讨复合施用聚丙烯酰胺(PAM)和粉煤灰改良沙土时,重金属(以Cr、As、Ni为例)在土壤、植物当中的运移规律,以及PAM在粉煤灰改良土壤中对重金属运移规律的影响。采取田间小区试验的方法,设计3种PAM施用量(0、60和120 mg/kg)和4种粉煤灰施用量(0、5%、10%和15%),其中不添加PAM和粉煤灰的处理为对照。试验结果表明:添加粉煤灰后,表层沙土当中Cr、Ni元素含量增加,而粉煤灰施用量为15%时As元素含量减少。在粉煤灰改良土壤中添加PAM能够将更多重金属固定在土壤表层,从而抑制重金属的淋洗,同时减少玉米对Cr、As、Ni的吸收。

Metal Transportation and Accumulation in Sandy Soil Amended by Fly Ash and PAM

Polyacrylamide (PAM) was added to fly ash to amend sandy soil. The migration of heavy metals, such as Cr, As and Ni in soil-plant system and the influence of PAM on it were investigated, respectively. The experimental design included three PAM application rates (0, 60mg/kg and 120mg/kg) and four fly ash application rates (0, 5%, 10% and 15%). The treatment without fly ash and PAM was prepared as a control. The results showed that the addition of fly ash increased the concentrations of Cr and Ni in the surface sandy soil, while there was a decline in As concentration at high fly ash application rates (15%). The addition of PAM could stabilize a large quantity of heavy metals within topsoil to control their leaching risk as well as reduce the amounts of Cr, As and Ni absorbed by corn.