Papers by Keyword: Aged Refuse

Abstract: Re-processing of aged refuse with particle size of 100mm, heating value above 3000kcal/kg above, chlorine content of about 0.13% was added into cement kiln as alternative fuels using screw conveyor. The results show that: except for NOx, emission rate and concentrations of TSPs, HCl, HF, SO2, CO from cement kiln flue gas were increased and volatized significantly after adding alternative fuels. Dosage of 2t/h of alternative fuels affected little on kiln system, so, main process parameters were normal and no more substantial fluctuations, but, the amount of feeding coal at calciner were adjusted more frequently. Element of S in hot raw material into the kiln seemed no significant changes while K and Cl content was significantly increased within the manageable range. Compressive strength, flexural strength, water demand for normal consistency, surface area of clinker all reduced when using alternative fuels, initial setting time and final setting time were increased compared with clinker saturation. Adding alternative fuels saving of coal, but the actual effect of alternative fuel was less than theoretical results, indicating that intermittent feeding mode was not desirable.

Abstract: Methanotrophs-bearing liquid cultivated from the aged refuse has been proved to be effective for improving methane oxidation ability of landfill cover materials, and this is significant for CH4 emission control in landfill site. Optimization of mixed-cultivation conditions of methanotrophs from the aged refuse was studied in this paper. It was demonstrated that the best inoculums mode was using supernatant liquor of the aged refuse and nitrate minimal salt medium (NMS), and the lag phase of the growth was only 37 hours. The optimum growth of methanotrophs was observed at 28~35°C. Paraffin was attested to be useful for mixed methanotrophs cultivation and the highest methane oxidation rate reached 4mL/h with paraffin added.

Abstract: The effect of temperature on two stage aged-refuse-based reactor which treats leachate in natural ventilation was investigated in autumn and winter. Results indicate that the average concentrations of COD in treated effluent increase from 726 mg/L in autumn to 2000 mg/L in winter in the first stage reactor while they are 246 mg/L and 1010 mg/L respectively in the second stage reactor. The average concentrations of NH3-N in treated effluent increase from 123.7 mg/L in autumn to 620 mg/L in winter in the first stage reactor while they are 123.7 mg/L and 620 mg/L respectively in the second stage reactor. Accordingly, the average removal rates of COD decrease from 81.7% of autumn to 73% of winter in the first stage reactor and decrease from 64.7% to 52% in the second stage reactor, and finally, the total COD removal rate in this system drops from 92.7% in autumn to 85.8% in winter. So we can conclude that the effect of temperature on the first stage aged refuse reactor is better than that on the second stage aged refuse reactor.