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Effects of Different Organic Bulking Agents on Nitrogen Loss During Composting of Dewatered Bioleached Sludge on a Commercial Scale |
Received:July 01, 2015 |
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KeyWord:bioleached sludge;composting;organic bulking agent;ammonia volatilization |
Author Name | Affiliation | E-mail | HU Wei-tong | College of Resource and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China | | YU Ya-lin | College of Resource and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China | | LI Zhe | Wuxi XinLi Environmental Biotechnology Co., Ltd. Wuxi 214000, China | | CUI Chun-hong | College of Resource and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China | | ZHOU Li-xiang | College of Resource and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China | lxzhou@njau.edu.cn |
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Abstract: |
In this study, the effects of different organic bulking agents on ammonia volatilization and composting process were studied during windrow composting of bioleached dewatered sludge. The bulking agents included rice hull, wheat bran, and mixture of mushroom residue with rice hull. Composting of bioleached sludge with wheat bran yielded the highest composting temperature, the longest high-temperature(> 50 ℃) duration, and the greatest organic matter decomposition rate. The cabbage seed germination index(GI) in this compost product was greater than 90%. It demonstrated that wheat bran was an efficient bulking agent for accelerating maturity during bioleached sludge composting. However, mushroom residue and rice hull mixture reduced ammonia emissions, resulting in cumulative ammonia emission 69% lower than that of the composting system with wheat bran, and 46% lower than that of the composting system with rice hull. Consequently, total N content in compost products with mushroom residue and rice hull mixture agent was 23.6% higher than before composting, and also higher than that from the compost products with rice hull or wheat bran. Scanning electron microscope showed that mushroom residue was of porous structure and high specific surface area, facilitating ammonia adsorption. The nitrogen content in dry mushroom residues was up to 5.1% when the adsorption was saturated. Therefore, mushroom residue should be a superior bulking agent for bioleached sludge composting. |
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