摘要
城市污泥是一种富含作物生长需要的多种养分的生物固体废弃物,但重金属问题又成为影响污泥农用的关键因素,而重金属的生物活性、迁移性及毒性不仅取决于总量,很大程度上取决于其存在的形态。该实验通过调节城市污泥的水分和C/N比,利用笔者所在课题组自行开发的好氧堆肥反应器进行城市污泥堆肥处理,经过为期20d的好氧堆肥处理,研究堆肥前后污泥中的重金属总量和化学形态的变化。实验结果表明:堆肥处理由于添加能源调理剂等,使堆肥产品中的重金属含量低于原污泥,符合了农用污泥污染物控制标准;同时堆肥也改变了重金属的化学形态,降低了剧毒性的Cd的生物有效性。对污泥及堆肥的重金属形态研究发现:大部分重金属主要以残渣态形式存在,生物毒性很小,农用时的重金属污染度也很低。
Municipal sewage sludge was biosolid waste which contained lots of nutrients for plants. But the heavy metals limited its utilization in agriculture. The toxicity of heavy metals depends on its total content and its chemical form, especially on the latter, The transition of heavy metals in municipal sewage sludge during aerobic composting was studied in this paper. The study showed that the total amount of heavy metals decreased and the biovalidity of Cd dropped after 20 days of reactor composting with amendment of chicken dung which could promote microbiolactivity and composting process. The chemical forms of the most heavy metals in the sludge and its compost was residue, which assured the low heavy metal pollution for their agriculture utilization.
出处
《生态环境》
CSCD
北大核心
2008年第3期940-943,共4页
Ecology and Environmnet
基金
广东省环保局科技研究开发项目(2001-28)
关键词
城市污泥
好氧堆肥
重金属
化学形态
municipal sewage sludge
aerobic composting
heavy metals
chemical form
