施垃圾堆肥拌CaCO_3对蔬菜中重金属的累积影响

EFFECT OF APPLICATION OF GARBAGE COMPOST WITH CaCO_3 ON THE ACCUMULATION OF HEAVY METALS IN VEGETABLES

垃圾堆肥拌施ＣａＣＯ３对蔬菜中重金属的累积效应试验结果显示：单施垃圾肥会增加蔬菜中重金属的累积量，但若施垃圾堆肥同时拌施ＣａＣＯ３（按施垃圾堆肥量的０．５％或１％），则可有效地降低蔬菜中重金属的累积水平．与单施垃圾堆肥相比，拌施ＣａＣＯ３能使番茄中Ｐｂ含量下降２９％－４１％；Ｃｒ下降５％－４６％，Ｃｄ下降９％－４２％；Ｃｕ下降２％－２４％；ＡＳ下降４％－６０％；有的元素如Ｐｂ和Ｃｄ甚至能降到本底值（即不施垃圾肥者）以下。青菜中Ｐｂ、Ｃｕ、Ａｓ的含量下降较明显。试验还显示：施垃圾堆肥拌施ＣａＣＯ３，土壤中重金属可提取总量低于单施垃圾堆肥者。

The results indicated that garbage compost application could increase heavy metal accumulation in vegetables. However, adding CaCO3 (0.5% or 1% of garbage compost) could effectively decrease the accumulation. The addition of CaCO3 could decrease heavy metal levels in tomato as: Pb by 29%-41%,Cr 5%-46%,Cd 9%-42%,Cu 2%-24% and As 4%-60%. Certain heavy metals,such as Pb,Cu and As could even be decreased below the level without applying garbage compost. In green vegetables the level of heavy metals,Pb,Cu and As was also significantly decreased after applying garbase compost with CaCO3. It was also indicated that the total amount of extractable heavy metals was much lower in soil applied with garbage compost with CaCO3 than in that with compost alone.