Study On Static Anaerobic Stabilization Process Of Rural Solid Waste

With China's rural economic development and improvement of living standards of farmers, the amount of rural solid waste is becoming larger. Data shows that the number of rural solid waste is 0.8-1.0kg per person per day in rural areas, which is about 70% to 80% of town. The rural solid waste has become one of the important reasons which affect the appearance of rural village and the living environment of farmers. At present, the treatments of rural solid waste include two major categories:traditional treatment and new methods. Existing forms of rural solid waste technology are difficult to adapt to the characteristics and requirements of the treatment about rural solid waste. So it is meaningful to research and development high processing performance, low running costs and easy management rural waste disposal technology. It is very important to solve the problem about environmental pollution caused by rural solid waste and reduce the economic costs of rural solid waste treatment. Solid waste disposal technology in rural areas exist high cost of garbage running, difficulties about selecting suitable landfill site, long term about management and maintenance, difficulties about the issues of new technology. In order to solve these problems, study on static anaerobic stabilization of rural solid waste was done.The study on static anaerobic stabilization treatment includes two aspects:experiment on the buffering effect of composite layer combined with construction waste and humus on VFA in recirculated leachate, experiment on the static anaerobic stabilization of rural solid waste.Experiment on the buffering effect of composite layer combined with construction waste and humus on VFA in recirculated leachate studied three composite filler layers gravel and humified refuse, broken bricks and humified refuse, broken concrete and humified refuse. The results indicate that:1) The buffering effect of the composite layer combined with broken concrete and humified refuse revealed the most excellent effect, namely leaching by 5d, the effluent VFA was not more than 1g/L.2) In order to achieve the buffering effect of VFA Recharge to reduce VFA inhibition of methanation process and speed up the process of landfill stabilization, it is necessary to fill broken concrete and humified refuse layer between the layers of garbage-garbage in leachate recirculation anaerobic bioreactor landfill unit.3) The gas loss of composite layer increased from 7mm water head to 90mm water head while the filling ratio of the humified refuse was added from 10% to 30%, the energy consumption should be moved up several times.4) The organic carbon remained in effluent was in form of dissolved organic salts, can be used by methanogens. Experiment on the static anaerobic stabilization of rural solid waste studied the effect on the process of anaerobic landfill stabilization of the leachate recirculation and anaerobic gas pumping by comparing it to traditional anaerobic landfill technology and bioreactor landfill technology. The experiment also studied the changes of leachate pH, COD, NH3-N, TN, TP, anaerobic landfill gas production trend over time in the three kinds of anaerobic waste treatment technology. The results showed that:1)The pH of bioreactor landfill simulated column and static anaerobic stabilization landfill simulated column showed a trend of increasing first and then decreasing, pH of traditional anaerobic landfill simulated column had been decreasing; pH of static anaerobic stabilization landfill simulated column was higher than others, this indicated that the composite filler layer played a buffer role to the organic acids in the leachate; the pH of the three simulated columns were below 7, this indicated the process of the anaerobic landfill was still in the acid stage.2) The COD of the three simulated columns showed the trend of increasing first and then decreasing over time; The COD of the three simulated columns experiments were able to reach the maximum COD:16936mg/L,14246mg/L,12552mg/L.3) The NH3-N, TN, TP of the three simulated columns showed the trend of decreasing first and then increasing and then decreasing over time. During the experiment, the NH3-N, TN, TP of the static anaerobic stabilization landfill simulated column had been the lowest. This is because composite filling layer of broken concrete-humus had a certain adsorption on NH3-N, TN, TP.4) The production of anaerobic landfill gas of the three simulated columns showed a trend of slow growth over time. The cumulative productions of gas of the three simulated columns were 1L,3.5L,5.5L after 22 days. The cumulative productions of gas in the static anaerobic stabilization landfill simulated column was maximum, this is mainly because it was pumped gas.