某市城市污水污泥后处置的能耗分析及投资运行比较

Comparison of Investment and Energy Consumption of Sewage Sludge Disposal Options in a City

吉林省某市现有3座污水处理厂,污泥主要采用脱水外运填埋方式,但填埋场库容日渐不足且二次污染严重,亟需探寻新的污泥处理处置方式。由于该市市政污水处理厂建有污泥消化设施,使其污泥处置方式的选择受到一定影响。为此,从实际情况出发,首先基于污泥是否消化从能量平衡角度分析了6种污泥处理处置方案;其次,基于能量平衡结果,比较了脱水污泥直接堆肥、脱水污泥直接焚烧、脱水污泥预干化/焚烧及消化后脱水污泥直接干化等处理处置方式的能耗投资及运行费用,最终确定选用污泥消化后干化外运的处置方案。

Nowadays there are three sewage treatment plants in a city of Jilin Province, and landfill of sewage sludge after dewatering is taken as the final disposal method. However, a new method of sludge treatment and disposal is needed because of the growing shortage of landfill capacity and severe secondary pollution. There are digestion facilities only in the municipal sewage treatment plant, so the establishment of sludge disposal method is affected to some extent. At first, six kinds of sludge treatment and disposal options are analyzed from the perspective of energy balance based on whether the sludge di- gestion or not. Then, based on the results of energy balance, the investment and operating costs of all options such as direct composting of dewatered sludge, direct incineration of dewatered sludge, pre-drying and incineration of dewatered sludge, and direct drying of dewatered sludge after digestion are compared. At last, the direct drying and transport out of dewatered sludge after digestion is selected as the final disposal option.