污泥热干化的研究进展

Research progress in thermal drying of sludge

首先阐述了在热干化过程中污泥的理化性质变化,污泥中大分子有机物分解为小分子有机物,酸溶态、可氧化态、可还原态等重金属形态转变为稳定的残渣态,降低了污泥处置的环境风险。随后,分析了污泥热干化过程出现的问题及其成因,针对污泥黏滞问题,总结了干污泥返混、添加降黏性物质及改造干化设备等方法;针对污染气体问题,综述了加入添加剂和降低温度抑制污染气体的释放,采用吸收法、吸附法和生物法处理产生的污染气体;针对设备腐蚀问题,归纳了采用防腐管材、防腐涂层、投加缓蚀剂和降低污泥含砂量的主要措施。最后对污泥热干化技术的研究趋势和发展提出了建议。

The changes of physicochemical properties of sludge during thermal drying were first described.Macromolecular organics in sludge were decomposed into micromolecule organics,and the forms of acid-soluble,oxidizable and reducible heavy metals were transformed into stable residue,which reduced the environmental risk of sludge disposal.Then,the problems and causes of in thermal drying process of sludge were analyzed.Aiming at the problem of sludge vicosity,the methods of dry sludge back mixing,adding viscosity reducing substances and reforming drying equipment were summarized.In view of the pollution gas problem,this paper summarized the methods of adding additives and the reduction of temperature to inhibit the release of polluted gas,and the pollution gas was treated by absorption,adsorption and biological methods.In view of the equipment corrosion,the main measures of using anti-corrosion pipes,anti-corrosion coatings,adding corrosion inhibitors and reducing the sand content of sludge were summarized.Finally,the suggestions on research trend and development of sludge thermal drying technology were proposed.