污泥与猪粪作为培养基微生物去除垃圾焚烧飞灰中的重金属

以污泥或猪粪代替常规的无机盐(SM)作为A.ferrooxidans和A.thiooxidans复合菌株的培养基,利用微生物淋滤法去除垃圾焚烧飞灰中的重金属.结果表明,重金属去除率大小顺序为:污泥+菌液>SM+菌液>猪粪+菌液.污泥+菌液的处理中,经过15d的微生物淋滤,Cd、Zn、Cu去除率最高分别达到88.1%、78.7%、69.6%,而猪粪+菌液的处理,3种金属的去除率分别为82.4%、73.5%、60.0%.试验也表明,相同浓度的猪粪DOM对硫杆菌复合菌株的抑制作用远大于污泥DOM.当污泥DOM和猪粪DOM中水溶性有机碳浓度分别高于400mg/L和150mg/L时,就表现出对硫杆菌的不可修复的抑制作用.猪粪DOM中小分子量组分较多是造成这一现象的主要原因.

Bioleaching of Fly Ash from Municipal Solid Waste Incinerator Using Sewage Sludge and Pig Manure as Culture Media

A mixed culture of Acidihiobacillus ferrooxidans and Acidihiobacillus thiooxidans was used to leach heavy metals from municipal solid waste incineration fly ash(MSWI fly ash).This study explored the possibility of using sewage sludge or pig manure as nutrients for supporting the growth of the leaching bacteria and allowing metal solubilization like a synthetic mineral medium.In contrast to pig manure,there is a high ability for acidification of the fly ash and solubilization of toxic metals using sewage sludge at the same content.After 15d of bioleaching,the following removal efficiencies were obtained for the treatment with the addition of 1% sewage sludge: Cd 88.1%;Zn 78.7%;Cu 69.6%,whereas their removal efficiencies for the treatment with the addition of 1% pig manure were 82.4%,73.5% and 60.0%,respectively.Results demonstrate that the inhibition by sewage sludge DOM is much more significant than by pig manure DOM at the same concentration level.The dissolved organic carbon in excess of 400 and 150 mg/L was inhibitory to the bacterial growth using sludge DOM and manure DOM,respectively.Compared with sewage sludge,pig manure contained a higher fraction of DOM with molecular size(<1 000,) which led to its higher toxicity.