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环境科学学报 2004
Effect of application of P fertilizer on efficiency of As removal from As-contaminated soil using phytoremediation: Field study
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Abstract:
Phytoremediation is a promising new technology that using hyperaccumulating plants to remove heavy metals. A field experiment was conducted to study the effect of P fertilizer on growth of and As accumulation in Pteris vittata L., an As-hyperaccumulator. Yields of P. vittata were enhanced with increasing P addition, however there was no further increase when rate of P addition was more than 200kg·hm-2. Application of P fertilizer could enhance As concentration, and As concentration in the aboveground of P. vittata was depressed because of excessive P addition. Theoretically, As concentration of plant reaches a maximum of 1622mg·kg-1 when rate of P addition is 340kg·hm-2. There was a significantly positive relationship between rates of P addition and P concentrations in the aboveground. Plant treated with 200 kg(P)·hm-2, accumulated 3.74 kg(As)·hm-2 in its aboveground part, which was 2.4 times more than the control and 1.2 times more than that in plant treated with 600 kg (P)·hm-2. After 7 months of the experiment, soil As concentrations were significantly reduced in all treatments at harvest compared to those before transplanting. When rate of P addition was 200kg·hm-2, efficiency of As removal was the highest (7.84%), while efficiencies of As removal at control and 600 kg·hm-2 treatments were 2.31% and 6.63%, respectively. The highest efficiency of As removal in theory could be achieved at 369kg·hm-2 P addition. Moreover, the results also showed that P application was helpful to maintain a balance of available As between before transplanting and after harvest. Application of P fertilizer is necessary for phytoremediation using As-hyperaccumulator; and optimized P application could significantly enhance the efficiency of As removal from contaminated soils.
