Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(...Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(30%, 60%, and 80%, dry matter) were applied to pretreat wheat straw for 7 days. The pretreated wheat straws were anaerobically digested at three loading rates(50, 65, and 80 g·L-1) to produce biogas. The results indicated that the wheat straw pretreated with 80% moisture content and 4% ammonia achieved the highest methane yield of 199.7 ml·g-1(based on per unit volatile solids loaded), with shorter digestion time(T80) of 25 days at the loading rate of 65 g·L-1compared to untreated one. The main chemical compositions of wheat straw were also analyzed. The cellulose and hemicellulose contents were decomposed by 2%-20% and 26%-42%, respectively,while the lignin content was hardly removed, cold-water and hot-water extracts were increased by 4%-44%, and12%-52%, respectively, for the ammonia-pretreated wheat straws at different moisture contents. The appropriate C/N ratio and decomposition of original chemical compositions into relatively readily biodegradable substances will improve the biodegradability and biogas yield.展开更多
基金Supported by the National High Technology Research and Development Program of China(2008AA062401)the China-US International Cooperation Project(2011DFA90800)the Ministry of Science and Technology,China
文摘Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(30%, 60%, and 80%, dry matter) were applied to pretreat wheat straw for 7 days. The pretreated wheat straws were anaerobically digested at three loading rates(50, 65, and 80 g·L-1) to produce biogas. The results indicated that the wheat straw pretreated with 80% moisture content and 4% ammonia achieved the highest methane yield of 199.7 ml·g-1(based on per unit volatile solids loaded), with shorter digestion time(T80) of 25 days at the loading rate of 65 g·L-1compared to untreated one. The main chemical compositions of wheat straw were also analyzed. The cellulose and hemicellulose contents were decomposed by 2%-20% and 26%-42%, respectively,while the lignin content was hardly removed, cold-water and hot-water extracts were increased by 4%-44%, and12%-52%, respectively, for the ammonia-pretreated wheat straws at different moisture contents. The appropriate C/N ratio and decomposition of original chemical compositions into relatively readily biodegradable substances will improve the biodegradability and biogas yield.
