摘要
持水量是进行生活垃圾预脱水效果评估的重要参数。通过开展8组新鲜高厨余垃圾持水量试验,分析应力压缩和生化降解对持水量的影响规律和机制。上覆应力越大,垃圾持水量越小,主要由孔隙水持有能力减小和胞内水释放量增加所造成;降解条件越有利,垃圾持水量下降速率越快,主要与胞内水释放速率增大有关。建立同时考虑应力压缩与生化降解作用的持水量预测模型,评估6个应力水平和6种降解条件下的垃圾预脱水效果,能够为预脱水工程设计提供理论依据。对预脱水工艺推荐了较优的技术方案:进料前掺入约1.5‰干垃圾质量的纤维素酶,进料后堆体顶部施加应力100 kPa,侧壁以300~400 L/kg干垃圾/天的速率通入空气,底部负压抽气,温度控制在(40±3)℃,处理至少3 d后脱水率可达50%以上。
Moisture retention capacity(MRC)is a key parameter to evaluate the pre-dewatering of municipal solid waste(MSW).In this paper,eight sets of MRC tests were conducted on fresh MSW with high food content,and the influence and mechanism of stress and degradation on MRC were analyzed.MRC of MSW decreased with an increase in stress,which was mainly caused by the decrease of inter-particle water retention capacity and the increase of intra-particle water release.MRC of MSW decreased faster with elapsed time under more favorable degradation conditions,which was related to the increase in release rate of intra-particle water.A mathematical model was then proposed for the prediction of MRC in which the influences of stress and degradation were considered.The pre-dewatering effects of MSW piles were evaluated by using the proposed model,in which six levels of applied stress and six different degradation conditions were studied.The results can provide theoretical basis for the design of pre-dewatering project of MSW piles.An optimal technical program was then recommended:mixing the cellulose enzyme into MSW with a dosage of about 1.5‰of the dry mass of MSW,and then applying a stress of about 100 kPa on top of the MSW pile,and then introducing air into the MSW pile at a rate of 300-400 L/kg-dry-MSW/day from the side wall and applying negative pressure at the bottom,and meanwhile controlling the temperature at(40±3)℃.Under the above conditions,the dewatering rate of MSW pile is promising to reach above 50%after treating for at least 3 days.
作者
尉明亮
徐辉
吴斌海
詹良通
张振营
WEI Mingliang;XU Hui;WU Binhai;ZHAN Liangtong;ZHANG Zhenying(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou,Zhejiang 310018,China;Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education,Zhejiang University,Hangzhou,Zhejiang 310058,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第S01期2994-3004,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51708508)
浙江省自然科学基金资助项目(LY21E080029)。
关键词
土工试验
城市生活垃圾
持水量
应力压缩
生化降解
预测模型
预脱水
geotechnical test
municipal solid waste(MSW)
moisture retention capacity(MRC)
stress induced compression
biodegradation
prediction model
pre-dewatering
