鸡粪与果蔬废弃物混合基质的厌氧发酵产氢特性

Characteristics of hydrogen production from anaerobic co-fermentation of chicken manure with fruit and vegetable wastes

【目的】探究鸡粪与不同果蔬废弃物混合基质的厌氧发酵产氢特征,为利用混合物料厌氧发酵制氢提供依据。【方法】分别以香蕉皮、白菜废弃物、油麦菜废弃物、笋叶、土豆皮渣与鸡粪的混合物为原料(各45mL),在中温(35±1)℃、混合基质初始COD质量浓度为40g/L的条件下进行厌氧发酵试验,测定发酵过程中的气体产生量、气体成分和发酵结束后的发酵液液相代谢产物。采用Modified Gompertz模型对累积产氢量随时间的变化进行拟合,测定发酵前、后发酵液的挥发性固体、碳水化合物和蛋白质含量,并计算三者的降解率。【结果】不同混合基质的累积产氢量依次为:鸡粪+土豆皮渣(87.5mL)>鸡粪+香蕉皮(62.5mL)>鸡粪+白菜废弃物(42.1mL)>鸡粪+油麦菜废弃物(34.4mL)>鸡粪+笋叶(34.2mL)。在混合基质初始COD质量浓度相同的条件下,不同混合基质的COD产氢率依次为:鸡粪+土豆皮渣(46.04 mL/g)>鸡粪+香蕉皮(34.00 mL/g)>鸡粪+白菜废弃物(22.24mL/g)>鸡粪+油麦菜废弃物(18.64mL/g)>鸡粪+笋叶(18.57mL/g)。采用Modified Gompertz模型可以很好地拟合各混合基质累积产氢量随时间变化的过程。以鸡粪+土豆皮渣和鸡粪+香蕉皮为混合底物时,发酵类型为丁酸型发酵;以鸡粪+白菜废弃物、鸡粪+油麦菜废弃物和鸡粪+笋叶为混合底物时,发酵类型为乙酸型发酵。在5种混合基质中,鸡粪+土豆皮渣组的挥发性固体、碳水化合物和蛋白质降解率均最大,分别为51.82%,62.43%和28.90%。【结论】基质类型是影响厌氧发酵产氢的重要因素,5种混合基质均能产氢,但以鸡粪+土豆皮渣混合物料的产氢能力最强。

【Objective】This study investigated the characteristics of anaerobic fermentation for hydrogen production by mixed substrates of chicken manure with different fruit and vegetable wastes.【Method】The batch anaerobic fermentation experiments with the mixtures of banana peels,Chinese cabbage waste,leaf lettuce waste,asparagus leaves,potato pulp and chicken manure were carried out under(35±1)℃with initial substrate COD concentration of 40 g/L and the volume respectively were 45 mL.Gas production and composition during anaerobic fermentation were monitored and final metabolic products after anaerobic fermentation were analyzed.The cumulative hydrogen production during the batch experiments was fitted with the Modified Gompertz model.Volatile solid,carbohydrate and protein contents before and after anaerobic fermentation were measured for calculating their degradation rates.【Result】The accumulative hydrogen productions of different mixtures were in the order of chicken manure+potato pulp(87.5 mL)>chicken manure+banana peel(62.5 mL)>chicken manure+Chinese cabbage waste(42.1 mL)>chicken manure+leaf lettuce waste(34.4 mL)>chicken manure+asparagus leaves(34.2 mL).The COD hydrogen rates of different mixtures were in the order of chicken manure+potato pulp(46.04 mL/g)>chicken manure+banana peel(34.00 mL/g)>chicken manure+Chinese cabbage waste(22.24 mL/g)>chicken manure+leaf lettuce waste(18.64 mL/g)>chicken manure+asparagus leaves(18.57 mL/g).Modified Gompertz model could well fit the change of accumulative hydrogen production with time.The fermentation of chicken manure+potato pulp and chicken manure+banana peel was butyrate-type,while the fermentation of chicken manure+Chinese cabbage waste,chicken manure+leaf lettuce waste and chicken manure+asparagus leaves was acetate-type.The maximum degradation rates of volatile solid,carbohydrate and protein were 51.82%,62.43%and 28.90%in the mixture of chicken with potato pulp.【Conclusion】Substrate type was the main factor influencing hydrogen production.All mixtures had hydrogen production potentials and the mixture of chicken with potato pulp was the best.