厨余垃圾干法厌氧沼渣陈腐化工艺方式探析

Study on the Rotten Process Scheme for Drying Anaerobic Biogas Residue of Household Food Waste

厨余垃圾经干法厌氧工程产生一级和二级沼渣,其植物毒性高,生物稳定性差,不能直接施用于土壤,需陈腐化提高腐熟度,但目前缺乏厨余垃圾干法厌氧沼渣特性相适宜的陈腐化工艺方式研究。对比了一级沼渣直接陈腐化、二级沼渣浆液陈腐化、二级沼渣添加稻秸陈腐化、以及二级沼渣添加稻秸加热陈腐化4种工艺方案,研究了4种工艺下堆温、含固率、挥发性有机质、生物稳定性、以及植物毒性的变化规律。结果表明,二级沼渣浆液陈腐化效果最差;一级沼渣直接陈腐化和二级沼渣添加稻秸陈腐化可满足标准关于生物毒性和植物稳定性最低要求,但堆温较低,产物含水率较高;二级沼渣添加稻秸加热陈腐化效果最好,与不加热工艺相比,可缩短45%陈腐化时间。本研究可为我国厨余垃圾干法厌氧沼渣资源化利用提供数据支撑。

The first and second grade biogas residue produced by the dry anaerobic engineering process of household food waste can not be directly applied to soil because of its high plant toxicity and poor biological stability.It needs to be further decomposed to improve the degree of putrescibility.However,currently there is a lack of research on the rotten process scheme for the dry anaerobic biogas residue of household food waste.In this paper,four rotten process schemes,which are the first grade biogas residue direct decomposition,the second grade biogas residue slurry decomposition,second grade biogas residue with rice straw decomposition,and the heat decomposition of second grade biogas residue with rice straw,were compared.And the variation tendency of pile temperature,total solid content,volatile organic solid content,biological stability,and plant toxicity were studied.The results showed that the rotten effect of second grade biogas residue slurry decomposition was the worst.The first grade biogas residue direct decomposition process and the second grade biogas residue with rice straw decomposition process can meet the minimum requirements of biological toxicity and plant stability,but the pile temperature was low and the moisture content was high,which were difficult to meet standards.The effect of heating second grade biogas residue with rice straw was the best,which could shorten the rotten time by 45%compared with that without heating.This research can provide data support for resource utilization of dry anaerobic biogas residue of household food waste in China.