污泥对樟子松生物量及其重金属积累和土壤重金属有效性的影响

采用盆栽试验研究了不同剂量污泥(体积分数,即污泥体积占污泥和沙土总体积的百分比,分别为:0、20%、33.3%、50%和100%)施用于风沙土条件下,污泥剂量对樟子松幼苗生物量及其对重金属的累积和土壤中重金属有效性的影响.结果表明,在养分含量低的风沙土中,施用污泥能够显著提高樟子松幼苗生物量,最适剂量为50%;污泥剂量的增加可促进樟子松植株对重金属的吸收和累积,在最适剂量(50%)条件下,樟子松植株中Cu、Cd、Pb、Zn的累积量分别是对照(不施污泥)的18.0、8.9、17.1、11.5倍;樟子松植株重金属吸收速率顺序为:ZnCuPbCd,而迁移系数顺序为:ZnCdCuPb;土壤中有效态重金属含量随污泥剂量的增加而增加,而植株收获后土壤中有效态重金属下降幅度均小于对照.

Effect of municipal sewage sludge on the biomass and heavy metal accumulation of Mongolian pine(Pinus sylvestris var.mongolica) and heavy metal availability in the soil

The dose-response effects of municipal sewage sludge (volume fractions 0, 20%, 33.3%, 50% and 100%) on growth and heavy metal accumulation of Mongolian pine (Pinus sylvestris var. mongolica) seedlings grown on aeolian sandy soil and the availability of heavy metals in the soil were studied in pot experiments. The results showed that sewage sludge significantly increased the biomass of Mongolian pine seedlings grown on the aeolian sandy soil, which has low levels of nutrients, and the optimum dose of sewage sludge is 50%. The absorption rate of heavy metals into various organs of Mongolian pine plants was increased by the increase of sewage sludge doses. Using the optimum dose of 50% added sludge, the accumulated quantity of Cu, Cd, Pb and Zn in the Mongolian pine plants were 18.0, 8.9, 17.1 and 11.5 times those of the control, respectively. The uptake rate of heavy metals by Mongolian pine was in order of Zn >Cu >Pb> Cd. However, the translocation factors of heavy metals was in the order Zn > Cd >Cu >Pb. The availability of heavy metals was increased by the increase of sewage sludge doses in the soil, and after the plants had been harvested the availability of heavy metals in the soil decreased less than in the control.