| To solve the increasingly serious problem of municipal waste, various effective methods of garbage disposal have been developed by many countries. As a ripe and low cost disposal technology, sanitary landfill is especially suitable for the conditions of our country. However, leachate is the principal environmental problem of landfill all over the world. Although leachate can reach or be close to the increasingly strict emission standard through various handling technologies or the combination of several technologies, it is nearly impossible for the undeveloped regions to accept the high cost. It's important and significative for the environmental protection of our country and even the world to develop the leachate handling technology based on land disposal considering its simple, economical and practical characters.According to the development of the leachate treatment technology overseas at present and considering the reality of our country, the recirculation technology of leachate is a very promising method to China. The technology of recirculation has had extensive application foundation in abroad. China also has developed much study on it. The imitated leachate recirculation experiments get an effective result. Both CODa and BOD5 have relatively high removal ratio. But the interior research work mostly limited in the laboratorial simulation of processing technique and the removal of CODCr and BOD5. The research on the removal of NH4+-N and the influencing factors during recirculation such as temperature, etc is comparatively limited.To solve this problem, the writer imitates the burying condition of the landfill sites in laboratory to operate the leachate recirculation process with garbage burying column. The factors such as hydraulic load, organic load, pH value, C/N, etc have been investigated. In-depth research on the removal regulation of the contaminants in the process of leachate recirculation especially ammonia-nitrogen has been done under different conditions both in high temperature and in low temperature.Through the research of this paper, a conclusion can be drew as thefollowing:IIIThe leachate recirculation of garbage burying column has remarkable removal ratio of NH4+-N, CODcrand BOD5 in leachate. The removal of BOD5 has little relation to the temperature. It nearly doesn't have problem in the start-up of reactor. The removal ratio of BOD5 stabilizes above 80% when the hydraulic load is not larger than 44.32 ml/L-d. The removal of CODcr: During the period of high temperature, when the hydraulic load increases gradually from 4.92 ml/L-d to 39.39 ml/L-d, the water quality of the effluent doesn't changes too much and the removal ratio stabilizes above 70% mostly; During the period of low temperature, the removal ratio of CODo can only reach 40% even if the hydraulic load is as low as 4.92 ml/L-d. The removal of NH4+-N: During the period of high temperature, when the hydraulic load is 4.92 ml/L-d, the treatment effect gets steady in very short time and the removal ratio stabilizes above 96%. When the hydraulic load increases in the range of 4.92~34,74 ml/ L-d, the water quality of the effluent doesn't change too much and the removal ratio of NH4+-N stabilizes above 90%. But when the garbage burying column reaches the saturation adsorption quantity, the concentration of NH^-N in effluent rises quickly and the removal ratio drops below 60%. When the hydraulic load goes up to 54.17 ml/L-d the removal ratio of NH4+-N is only 41.22%; During the period of low temperature, when the hydraulic load is 4.92 ml/L-d, NH4+-N can only be removed around 60%.The reaction process occurs in garbage burying column and the influencing factor of recirculation effect have been discussed in this paper. Further discussion on the removal mechanism of BOD5, CODcr, especially NH4+-N in leachate has also been made.
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