基于碳中和的城市居民厨余垃圾厌氧发酵中添加复合菌剂抑制甲烷特性研究

在我国“碳达峰碳中和”战略目标下,如何不产生或少产生温室气体,并实现厨余垃圾的资源化循环利用,达到“餐桌—田间—餐桌”的闭合循环,成为低碳处理厨余垃圾的关键。基于厨余垃圾厌氧发酵实验,对比分析有无添加复合菌剂(高活性兼性微生物菌群与生物活性酶)的产气能力、气体组分、产气潜力、折合碳减排情况。研究表明:添加菌剂后延滞了厨余垃圾厌氧发酵产CH4的能力,增加了产CO_(2)的能力,对实现碳循环和减排提供了技术支撑;添加菌剂后,产生的气体以CO_(2)为主,相对于CH4可极大减少温室气体排放效应。对比填埋、好氧堆肥分别减排798,177 kg CO_(2)当量;添加复合微生物菌剂可有效提高发酵底物中的腐植酸、黄腐酸相对含量,腐植酸含量约为对照组的3倍,表明该发酵底物具备有效促进植物生长、改善土壤性能的作用;该方法对农业增产、节能降碳有极大助力,按2022年约50%城镇人口所产生的厨余垃圾计,可实现温室气体减排约12.9万t CO_(2)当量,生活垃圾含水率下降大于25%,1 t垃圾发电量增加160~420 kW·h,耕田土壤有机质增加322万t,折合化肥年减用量92.2万t。

Under the strategic goal of"reaching the peak of carbon and carbon neutrality"in China,how to produce no or less greenhouse gases,and realize the recycling of kitchen waste resources,and achieve the closed cycle of"table-field-table"has become the key to low-carbon food waste treatment.Aiming at anaerobic fermentation experiments based on kitchen waste,this paper compares and analyzes the gas production capacity,gas composition,gas production potential and reduced carbon emission of the two types of bacteria agent through the experimental practice of whether to add complex bacteria(highly active facultative microbial flora and biological active enzymes).The results showed that the addition of bacteria delayed the ability of anaerobic fermentation of kitchen waste to produce CH4,increased the ability of CO_(2) production,and provided technical support for carbon cycle and emission reduction.After adding the bacteria agent,the gas produced is mainly CO_(2),which can greatly reduce the greenhouse gas emission effect compared with CH4.By contrast,landfill and aerobic composting reduced emissions by 798 kgCO_(2) equivalent and 177 kgCO_(2) equivalent,respectively.The contents of humic acid and fulvic acid in the fermentation substrate were increased by adding the compound microbial agent,and the contents of humic acid were about 3 times that of the control group,indicating that the fermentation substrate could effectively promote plant growth and improve soil properties.This method has great help to increase agricultural production,save energy and reduce carbon.According to the kitchen waste generated by about 50%of the urban population in 2022,the greenhouse gas emission can be reduced by about 129000 tons CO_(2)-equivalent,the water content of domestic waste can be reduced by more than 25%,the power generation of per ton of garbage can be increased by 160-420 kW·h,and the soil organic matter in cultivated fields can be increased by 3.22 million tons,equivalent to the annual reduction of 922000 tons of fertilizer.