Research On The Effect Of Organic Solid Waste To Sewage Sludge Anaerobic Digestion

With the rapid development of economy and city construction as well as the improvement of people's living standard,kitchen waste,garden waste and other organic solid waste are increasing.How to use these wastes recycling and effectively remains to be resolved;In addition,the Biological degradation ability of sludge,the removal rate of volatile solids and the efficiency of gas production of urban waste water treatment plant is low.This paper takes the sewage sludge of Haibohe waste water treatment plant of Qingdao as the research object,respectively adds garden waste and kitchen waste to the sewage sludge to conduct medium temperature combined anaerobic digestion test,through the control of VS dosing ratio of organic solid waste(garden waste,kitchen waste)and sewage sludge to research the influence of sewage sludge anaerobic digestion performance and reaction process by organic solid waste,and provides a basis data support for the similar engineering of waste water treatment plant.The main conclusions of this paper are as follows,(1)Through the addition of organic solid waste(garden waste,kitchen waste)in the sludge of waste water treatment plant to conduct anaerobic digestion,it increased the content of organic matter of the hybrid system and improved the C/N ratio,and it also effectively improved the gas production of hybrid system.With the increasing of addition proportion between organic solid waste(garden waste,kitchen waste)and the sewage sludge,the degradation rate of dissolved organic matter,removal rate of organic matter and methane production of the system all increased.(2)When with the same VS dosing ratio of garden waste and sewage sludge to conduct anaerobic digestion,the specific methane production,maximum rate of specific methane production,removal rate of organic matter,degradation rate of dissolved organic matter of wet garden waste are higher than those of dry green waste.Such as,when the VS dosing ratio of garden waste and sewage sludge is 1:1,the specific methane production,maximum rate of specific methane production,removal rate of organic matter,degradation rate of SCOD,degradation rate of soluble carbohydrate,degradation rate of soluble protein of wet garden waste are respectively increased by 10.79%,9.46%,.5.13%,4.5%,1.85%,5.54% than those of dry garden waste.(3)In the initial stage of the anaerobic digestion reaction(first two days),the change rule of dissolved organic matter is different of dosing garden waste and kitchen waste.The organic compound in kitchen waste is more likely to happen hydrolysis acidification,the reaction rate of hydrolysis was quicker than the degradation rate of dissolved organic matter by microorganism in the initial stage,so the dissolved organic matter increased dramatically first which dosing kitchen waste.However,the content of refractory organics in garden waste is higher than kitchen waste and the hydrolysis acidification process is relatively slow,and microorganisms make full use of the dissolved organic matter which in the system after hydrolysis acidification,so the accumulation of dissolved organic matter is lesser at the beginning of reaction.(4)In the process of anaerobic digestion of organic solid waste(green waste,kitchen waste)and sewage sludge,the variation tendency of pH is decreased first and then increased.In the first 2 days of the anaerobic digestion reaction,high content of organic matter in the system was fully hydrolyzed by microorganisms,so the number of pH decreased rapidly,and with the reaction progressing,the content of organic matter reduced gradually,and the number of pH showed an upward trend.