摘要
以昆明地区污水处理厂脱水污泥为对象进行生物干化处理,考察了典型工况条件下污泥干化处理效果,探究了微生物活性及其有机质代谢,并对干化处理产物的土地利用潜力进行了评价分析。结果表明,采用污水厂脱水污泥进行处理时,混合物料初始含水率以65%左右较为适宜,采用底部间歇曝气+顶部间歇抽风的通风方式,堆体自热升温至60℃以上,高温期持续时间长达30 h;干化处理120 h时,含水率降低至50%以下,水分净去除率达到16%。干化进程中,混合料中DOC质量浓度呈降低趋势,但SCFAs组分及其浓度波动明显。伴随着堆体温度的变化,常温、中温或嗜热微生物发生更替,微生物活性及其生化代谢差异明显。干化产物中可溶性磷以及氮钾质量分数均较高,重金属Cd、As、Hg满足GB4284-2018 B级标准限值,Cr、Pb等其他重金属质量浓度满足A级标准限值,种子发芽指数GI值高达90%,污泥干化产物具备园林绿化、矿山修复等方面土地利用前景。本研究结果可为污水厂污泥处理处置及资源化利用提供参考。
Biological drying was employed to treat the dewatered excess sludge derived from sewage treatment plants in Kunming.The effects of sludge biodrying were investigated under typical parameters,the microbial activity and substrate metabolism were elucidated,and then the potential of land utilization for the drying products was analyzed.The results showed that when the dewatered sludge from sewage plant was used for treatment,the optimum moisture content of the mixed materials was about 65%,the mode of ventilation was intermittent bottom aeration combined with intermittent top suction,and the stack was self-heated to above 60℃,the period of thermophilic condition lasted for 30 h.After biodrying treatment for 120 h,the moisture content was reduced to less than 50%,and the water removal reached 16%.During the biodrying process,the content of DOC in the mixture presented downward trend,but the SCFAs and its concentration fluctuated significantly.As the temperature of the bioreactor changed,mesophilic or thermophilic microorganisms varied correspondingly,and the microbial activities and biochemical metabolism exhibited significantly different.For the drying products,the contents of soluble phosphorus and other nutrient elements such as nitrogen and potassium are abundant,the heavy metals Cd,As and Hg can meet the requirements stipulated by class B biosolids in GB4284-2018,and the other heavy metals such as Cr and Pb meet the standard of class A biosolids,and the seed germination index GI is up to 90%.The products after biodrying present the prospect of land utilization in garden landscaping,mine restoration and other aspects.The results can provide valuable supports for sludge disposal and land utilization.
作者
金熠
陈越
刘树根
吕学斌
刘庆岭
陈冠益
JIN Yi;CHEN Yue;LIU Shugen;LV Xuebin;LIU Qingling;CHEN Guanyi(Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China;Faculty of Environmental Science and Engineering,Tianjin University,Tianjin 300350,China;Tianjin University of Commerce,Tianjin 300134,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第5期1570-1579,共10页
Chinese Journal of Environmental Engineering
基金
科技部“固废资源化”重点研发计划项目(2019YFC1904102)
云南省中青年学术与技术带头人后备人才项目(202105AC160096)。
关键词
脱水剩余污泥
生物干化
水分去除
土地利用
dewatered excess sludge
biological drying
moisture removal
land utilization
