白灵菇种植基质废料和牛粪混合厌氧发酵产沼气特性研究

Biogas production characteristics of anaerobic fermentation of mixed Pleurotus ferulatus planting matrix wastes and cattle manure

以白灵菇种植基质废料和牛粪以2∶1的配比为原料,在35℃中温环境中,分别在6种不同TS质量分数(2%、4%、6%、8%、10%、12%)的条件下进行厌氧发酵制取沼气的试验,通过测定发酵过程中发酵液和沼气的各项指标,对白灵菇种植基质废料厌氧发酵的可行性及TS浓度对发酵过程的影响进行了研究,并分别采用Logistic模型、Transference模型和Modified Gompertz模型对甲烷产生过程进行拟合。结果表明,白灵菇种植基质废料用厌氧发酵工艺处理是可行的;试验得出最适宜厌氧发酵的条件是:在白灵菇种植基质废料和牛粪配比为2∶1的情况下(以干物质计),发酵液的总固体质量分数为8%,此种情况下发酵原料的TS转化率最高,为37.04%;单位TS产气量最大,为473.5mL/g。Logistic模型、Transference模型、Modified Gompertz模型都可较好地模拟白灵菇种植基质废料厌氧发酵产甲烷过程,其中ModifiedGompertz模型拟合效果最好。该项研究对白灵菇种植基质废料的资源化利用提供了有益的参考。

The cultivation of Pleurotus ostreatus produces a large amount of mushroom planting matrix wastes.The planting matrix wastes are rich in protein,amino acids and other nutrients.Discarding will cause serious waste of resources.If we apply the mushroom planting matrix wastes directly into the field,it will promote the growth of mold and pests,increase the number of harmful spores and pests in the air,and this way will also cause bacterial reproduction and disease transmission.If we burn the mushroom growing substrate directly,then we can only get about 10%of the heat.Those treatment methods will cause huge waste of agricultural organic resources and environmental pollution.Reasonable development and utilization of mushroom planting matrix wastes can not only utilize resources as much as possible and reduce environmental pollution.Therefore,how to properly handle mushroom planting matrix wastes becomes an urgent problem that needs to be solved.The research on converting mushroom planting matrix wastes into biogas by biological fermentation has gradually attracted people's attention.This method is considered to be a promising treatment method for mushroom planting matrix wastes.In this study,the mass ratio of waste to cow dung was 2:1,the fermentation temperature was 35℃,and the TS concentrations of anaerobic fermentation were 2%,4%,6%,8%,10%,and 12%.By measuring various indexes of fermentation broth and biogas during the reaction process,the feasibility of anaerobic fermentation for biogas from Pleurotus ferulatus planting matrix wastes was studied.The influence of TS concentration on fermentation process was studied.In this study,the Logistic model,the Transference model and the Modified Gompertz model were used to fit the characteristics of methane produced by anaerobic fermentation of Pleurotus ferulatus planting matrix wastes and cattle Manure.The results showed that in co-anaerobic fermentation using Pleurotus ferulatus planting matrix wastes and cattle manure as raw materials,the biogas production could be smoothly developed under 6 different concentrations,indicating that it is feasible to use Pleurotus ferulatus planting matrix wastes and cattle manure for anaerobic fermentation to obtain biogas.The experimental results showed that the optimum anaerobic fermentation TS mass fraction was 8%under the condition of 2∶1 ratio of raw materials.At this time,the TS removal rate and the unit TS gas production amount were the highest.The TS removal rate and VS removal rate were 37.04%and 39.03%,the unit gas production volume and unit VS gas production were 473.5 and 515.2 mL/g,and the cumulative gas production and average daily gas production were 17.25 and 8.77 mL/(g·d).Logistic model,Transference model and Modified Gompertz model could better describe the anaerobic fermentation for methane production in this study.Among the three models,the Modified Gompertz model had the best fitting effect.The study provides a reference for the resource utilization of the Pleurotus ferulatus planting matrix wastes.