南宁市城市污泥资源化与能源化处理处置研究

为促进南宁市污泥资源化与能源化处理,根据南宁市土地资源状况和污泥泥质,结合相关法规、政策和标准,对南宁市城市污泥处理处置进行研究。厌氧消化实验结果表明,南宁市污泥厌氧消化平均甲烷产率为158.4mL/g(TS)。南宁市每天产生的污泥用于厌氧消化产甲烷可发电43995kW·h,发电系统除满足污泥消化自身热能需要外,还有92.9%的电量富余。消化污泥重金属含量满足国家和广西地方土地利用相关标准要求。一年产生的消化污泥中其氮、磷、钾含量分别相当于1675.2t尿素、3454.4t过磷酸钙和473.0t氯化钾中的氮、磷、钾含量。消化污泥土地利用每年可节约氮、磷、钾肥开支6369040元。南宁市污泥处理处置宜采用厌氧消化+土地利用方式,有利于其中有用物质和能源的回收利用。

The treatment and disposal of sewage sludge combining with resource recycle and energy recovery was studied based on the chemical compositions of the sludge, regulations, policy, standards concerning sludge handling and the state of land resource in Nanning. The results of anaerobic digestion experiment of sewage sludge indicated that the production of methane was 158.4 mL/g (total solids). It was calculated that the methane power generation was 43 995 kW·h on the anaerobic digestion process with the sewage sludge produced in a day. The energy generated on the power generation process could meet the demand of heating for the anaerobic digestion process. There were savings of 92.9% energy. The amounts of heavy metals in the digested sludge met the qualities of sludge for land application. The nitrogen, phosphorous and potassium contents in the digested sludge produced in a year were equaled to 1 675.2, 3 454.4 and 473.0 t of urea, calcium superphosphate and potassium chloride, respectively. It could save ￥6 369 040 for the digested sludge by land application to replace chemical fertilizer. It suggested that anaerobic digestion and land application were appropriate for sewage sludge treatment and disposal in Nanning, which were propitious to resource recycle and energy recovery.