Xu Qiyong, Tian Ying, Wang Shen, Ko Jae Hac
Key Laboratory for Eco-Efficient Polysilicate Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong 518055, China.
Key Laboratory for Eco-Efficient Polysilicate Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong 518055, China.
Waste Manag. 2015 Jul;41:94-100. doi: 10.1016/j.wasman.2015.03.023. Epub 2015 Apr 7.
Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10months. The hybrid bioreactors were operated in an aerobic-anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia-nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75d and 60d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4L/kgvs and 113.2L/kgvs. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.
针对典型的中国城市生活垃圾，开展了研究以比较模拟厌氧和混合生物反应器填埋场中的渗滤液特性及沼气产生情况。构建了三个实验室规模的反应器，一个厌氧反应器（A1）和两个混合生物反应器（C1和C2），并运行了约10个月。混合生物反应器通过向废物上层提供空气，以不同曝气频率在好氧-厌氧模式下运行。结果表明，由于挥发性脂肪酸（VFA）减少和pH值升高，向上层进行临时曝气通过缩短初始产酸阶段有助于甲烷生成。混合生物反应器中的化学需氧量（COD）下降得更快，但混合生物反应器中氨氮的浓度高于厌氧对照中的浓度。C1和C2分别在75天和60天内建立了产甲烷条件。然而，高曝气频率导致有机物通过好氧降解而消耗，从而导致累积甲烷量减少。临时曝气增强了废物沉降，且沉降随着曝气频率的增加而增加。厌氧对照中甲烷产生受到抑制；然而，混合生物反应器的总甲烷产量分别为133.4L/kgVS和113.2L/kgVS。对于食物垃圾含量高的城市生活垃圾，由于VFA对产甲烷菌的抑制作用，不建议在曝气停止后立即进行渗滤液回流。
