高校餐厨垃圾制沼气与中水回用联合改造系统

Combined system for biogas production using kitchen wastes and recycled water

针对高校餐厨垃圾与生活污水的处理现状,提出了构建餐厨垃圾制沼气与生活污水回用良性互补的联合节能改造系统的思路,为高校节能工作创建了新的改造模式.在不同的餐厨垃圾与污泥混合比例条件下进行了产沼气实验,当混合比为1∶1时,40 d后的累积沼气产率最大,为621 m L/(g·VS),挥发性固体(volatile soild,VS)含量去除率高达67.5%,产甲烷效率为78.6%,为最佳混合比例.1∶1混合底物反应后溶解性化学需氧量(solluted chemical oxygen demand,SCOD)、溶解性碳水化合物及蛋白质的去除率分别为55.7%,68.7%,22.7%,较餐厨垃圾的发酵显著提高,底物的p H值基本在6.8～7.2之间.通过对上海大学南区进行的节能估算可知,改造后每年可节省耗能费约26万元,具有较好的经济效益.

Regarding the current situation of treatment of kitchen wastes and sewage in colleges, constructing a combined energy-saving system to produce biogas using kitchen wastes and recycled water is proposed. The two recycling systems have a complementary relation. It can provide a new mode of energy-saving work in general, and for colleges in particular. Different mixing ratios of kitchen wastes and sludge are considered in the experiment of biogas production. With the ratio of 1 ： 1, the cumulative yield of biogas reaches a maximum value. The cumulative biogas yield for 40 days is 621 mL/（g.VS）, the removal rate of volatile solid （VS） is up to 67.5% and efficiency of methane production is 78.6%. The removal efficiencies of solluted chemical oxygen demand （SCOD）, soluble carbohydrate and protein after the reaction by mixed substrate of 1：1 are 55.7%, 68.7%, and 22.7%, respectively. The pH values of the substrate is between 6.8 and 7.2. According to an estimation of energy saving in the South Campus of Shanghai University, the program can save energy costing 260 000 RMB every year after reconstruction, making a good economic benefit.