Research On Anaerobic Digestion Process Of Organic Solid Waste Under The Condition Of Complete Mixing

Anaerobic digestion is a way that makes organic matter change CO2 and CH4,witch has many advantages,such as little energy lost and sludge,and recoveres energy. It is one of ways to process organic solid wastes(OSW). This dissertation depends on Chongqing Municipal 2004'Academician Funds (2004 8260), make systems research about anaerobic digestion of OSW, as follows:â‘ On the basis of collecting and consulting much data, make systems summariziton for research achievements , application,mechanism and influencing factors in anaerobic treatment of OSW.â‘¡Design and manufacture two sets of equipment to process OSW. The first is named Complete Mixxing Anaerobic Digestion Auto-controlling equipment (abbreviating MADACE).The second is named"Simple Anaerobic Digestion Equipment". The characteristics of MADACE are followes: 1)On-line T,pH and ORP monitoring; 2)Digestion tank use oil as thermal media and has better heating function; 3)Digestion tank has better heat-protection funtion, heat lost is only 30% in winter; 4)Auto-heating and auto-controlling temperature. 5)Has over-persure and over-temperature protection installation. 6)Auto-collecting date.â‘¢Of three indexes(COD,TS,VS) which indicate the process of anaerobic digestion of orgacnic solid waste, VS is the best.VS value is decreased in the course of anaerobic digestion,meanwhile the VS change is continuous,so polynomial in one indeterminate and exponential function may show the VS change in the process of anaerobic digestion of orgacnic solid waste,the mathematical formula are nVS_t = a₀ +a₁t+a₂t₂+……+a_nt, VS_t = ae^bt.The two functions are feasible by experiments with MADACE , their correlation coefficients are more than 0.98.â‘£Suitable inoculation microorganism are favourable to the growth of mushroom, and make biogas emerge speedlly, but over-inoclllation is probable to influence anaerobic digestion.⑤Carrying out anaerobic digestion with MADECE, environmental temperature is higher 2⁴℃than in-tank temperature.In-tank temperature has relative stability. In the course of anaerobic digestion of OSW, firstly the value of pH drop, reaction enter"acid-stage". Then the value of pH rise gradually, reaction enter"methane-stage". After digesting ORP drop fastly, ten days later ORP is about 500mv.