城市污泥与稻草堆肥中铜锌的形态分布研究

Distribution of Forms for Copper and Zinc in Composting of Municipal Sludge with Rice Straw

将广州污泥、佛山污泥与稻草进行翻堆、加菌种-翻堆、连续通气、间歇通气和滚筒方式堆肥处理,研究堆肥中重金属铜、锌的含量与形态分布。结果表明,不同方式堆肥中全铜含量在412～451mg·kg-1,高低次序为:广州污泥-稻草+菌种-翻堆>广州污泥-稻草-滚筒>广州污泥-稻草-翻堆>广州污泥-稻草-间歇通气>广州污泥-稻草-连续通气>佛山污泥-稻草-翻堆;全锌含量在1374～1775mg·kg-1,高低次序为:广州污泥-稻草-连续通气>广州污泥-稻草-间歇通气>广州污泥-稻草-滚筒>广州污泥-稻草-翻堆>广州污泥-稻草+菌种-翻堆>佛山污泥-稻草-翻堆。与原污泥相比,堆肥处理后全铜、全锌含量增加,且全锌含量显著高于全铜含量;水溶态+交换态锌、铁锰氧化物态锌和残渣态锌含量显著高于对应形态铜的含量。不同方式堆肥中各形态铜的含量高低依次为:有机结合态>残渣态>水溶态+交换态>铁锰氧化物态;不同方式堆肥中铁锰氧化物态锌和水溶态+交换态锌含量较高,分别占全锌的37%左右和28.8%～32.7%;有机结合态锌占全锌量的14.2%～20.7%,残渣态锌占全锌10%左右。污泥堆肥处理后锌的生物有效性较铜高。

Composting of municipal sludge with rice straw by manual turning, inoculating-manual turning, continuous aeration, intermittent aeration was conducted to investigate contents and forms for both copper and zinc in the mixture. The results showed that the total contents of copper in different composts ranged from 412～451 mg·kg-1, with a decreasing order: Guangzhou sludge-inoculating-manual turning>tumbling box>manual turning> intermittent aeration>continuous aeration>Foshan sludge-manual turning; and those of zinc were between 1 374 mg·kg-1 and 1 775 mg·kg-1, with a decreasing order: continuous aeration>intermittent aeration>tumbling box-turning>manual turning>Guangzhou sludge-inoculating-manual turning>Foshan sludge-manual turning. Compared to the non-composted sludge, the total contents of copper and zinc in the composting of municipal sludge with rice straw were increased, and the total contents of zinc was significant higher than that of copper. Moreover, the contents of zinc in soluble +exchangeable zinc, Mn &Fe oxides and residue phase were significant higher than those of copper. The concentrations of different forms for copper in various composts decreased with an order of organic matter forms>residue>soluble +exchangeable>Mn &Fe oxides, while those of Mn &Fe oxides zinc and soluble +exchangeable zinc were higher than those of bound to organic matter forms and residue phase. It has also been found that the bioavailability of zinc was higher than that of copper in composts.