| The faecal sludge is used as fertilizer without treatment that leads to health risks. Handling faecal sludge is a way of transmission way for some human disease,70%of the disease is associated with the disease transmitted by faecal sludge in developing countries. Faecal sludge is not only pollution but also a kind of a resource. Faecal sludge is rich in organic matter, nitrogen, phosphorus and potassium element, which can be used as a feedstock for anaerobic digestion. In order to overcome the pollution problem of faecal sludge, sustainable sanitation combined with anaerobic digestion technology was used. Harmless pretreatment methods and anaerobic digestion process optimization were studied. Meanwhile, the rapid improvement of membrane material technology and fast paced development of biogas project have extensively boosted the applications of membrane maerials to biogas storage system. But there are no standards for characteristic indexes and testing methods for the biogas storage membrane at the national level or international level till now. In order to promote the development and application of the biogas storage membrane more efficently, a novel test method for evaluation of the methane permeability of biogas storage membrane was presented, and the effect of temperature and relative humidity (RH) on the biogas storage membrane permeability of methane were researched. The mainly results as shown on:(1) This paper studied the harmless pretreatment technology for faecal sludge. The results show that, the thermal (70℃) pretreatment is more suitable than alkaline pretreatment used as faecal sludge harmless pretreatment. Moreover thermal pretreatment can complete pathogen inactivation within60,60,80,80,100,100,100minutes for faecal sludge TS of1%,2%,4%,6%,8%,10%,12%respectively. The relationship between the time of complete inactivation and TS follow this equation y=18.549ln(x)+143.99. Thermal pretreatment also had a more significant effect on SCOD and protein solubilization, the value of S COD and soluble proteins were increased to1.28-1.47and4.30-6.59times, respectively.(2) The effect of thermal treatment on the faecal sludge characteristics was analyzed. After thermal pretreatment, the intergranula porosity of faecal sludge was lower, surface structure becomes smoother, skeletal structure was not damaged and only the functional group content has changed. In addition, the faecal sludge belongs to pseudoplastic fluid with the characteristics of a shear thinning. At the optimal mixing condition (G=772/s), thermal pretreatment can complete pathogen inactivation within80minutes at faecal sludge TS of8%.(3) The net energy and kinetics of gas production of faecal sludge fermentation were determined. The net energy used to digest a ton dry feces was398kWh for faecal sludge TS of8%, and the Gompertz model best fitted the test, with an average maximum correlation index (R2).(4) Based on the optimal experiment conditions, continuous stirred fermentation on Laboratory level was conducted. The effect of sludge retention time of the anaerobic digestion process for faecal sluge was discussed. At the sludge retention time of25days, the economic benefit of the biogas plant is the best.(5) A novel test method for evaluation of the methane permeability of biogas storage membrane was presented, and the effect of temperature and RH on the biogas storage membrane permeability were researched. Results demonstrated that when various membrane samples with the same RH values were tested, temperature exhibited a strong effect on permeability rate. Kinetic analysis showed that the relationship between permeability and temperature agrees with the Arrhenius equation. However, no remarkable variation in methane permeability was observed for membranes with the same temperature but different RH values, thus suggesting that RH nearly has no obvious direct influence on the permeability rate of membranes. |
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