title: Coal fly ash and lime addition enhances the rate and efficiency of decomposition of food waste during composting.
abstract: To evaluate the use of coal fly ash (CFA) on the decomposition efficiency of food waste, synthetic food waste was mixed with lime at 1.5% and 3% (equivalent to 0.94% and 1.88% CaCO(3), respectively), CFA at 5%, 10% and 15% with lime so as to achieve CaCO(3) equivalent of 1.88% and composted for 42 days in a thermophilic 20 l composter with two replicates each. Alkaline materials at 1.88% CaCO(3) equivalent successfully buffered the pH during the composting and enhanced the decomposition efficiency. When these buffering was achieved with CFA+lime, the composting period could be shortened to approximately 28 days compared with approximately 42 days in 3% lime. Organic decomposition in terms of CO(2) loss, carbon turnover and nitrogen transformation were significantly higher for treatments with 1.88% CaCO(3) equivalent. Nutrient transformations and compost maturity parameters indicated that addition of CFA (5-10%) with lime at 1.88% CaCO(3) equivalent enhances the decomposition efficiency and shortens the composting period by 35%.
authors.affiliation: Department of Biology, Sino-Forest Applied Research Centre for Pearl River Delta Environment, Hong Kong Baptist University, Kowloon Tong, Hong Kong. jwcwong@hkbu.edu.hk
authors.forename: Jonathan W-C
authors.initials: JW
authors.lastname: Wong
authors.forename: Shun On
authors.initials: SO
authors.lastname: Fung
authors.forename: Ammaiyappan
authors.initials: A
authors.lastname: Selvam
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002021:Buffers; D017610:Calcium Compounds / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D003031:Coal; D060729:Coal Ash; D003247:Conservation of Natural Resources / Q000379:methods; D005502:Food; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000737:chemistry; D009566:Nitrates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D052638:Particulate Matter / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D013696:Temperature
chemical_list: D002021:Buffers; D017610:Calcium Compounds; D003031:Coal; D060729:Coal Ash; D019216:Metals, Heavy; D009566:Nitrates; D010087:Oxides; D052638:Particulate Matter; D000644:Quaternary Ammonium Compounds; D002245:Carbon Dioxide; D002244:Carbon; C016538:lime; D009584:Nitrogen