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| Moisture retention capacity behavior and pre-dewatering method of fresh municipal solid waste with high food waste content |
| WEI Mingliang1，XU Hui1，2，WU Binhai1，ZHAN Liangtong2，ZHANG Zhenying1 |
| (1. School of Civil Engineering and Architecture，Zhejiang Sci-Tech University，Hangzhou，Zhejiang 310018，China；2. Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education，Zhejiang University，Hangzhou，Zhejiang 310058，China) |
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Abstract 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.
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2021, Vol. 40 
