进料负荷对中试规模餐厨和果蔬混合厌氧消化的影响

Pilot-scale Anaerobic Co-digestion of Food Waste and Fruit/Vegetable Waste: Effect of Organic Loading Rate

餐厨和果蔬垃圾作为城市生活垃圾的主体,产量巨大,其高含水率的特点给传统的垃圾处理方法带来极大压力.中试规模下将餐厨和果蔬垃圾按质量比8∶5混合后进行两相厌氧消化研究.在产甲烷相有机负荷为1,2,3 kgVS·m-3d-1时,系统pH值始终维持在7.0 ～7.3之间,产气性能良好,负荷产气量和VS去除率分别为0.97,0.78,0.72 m3·kg-1VS和84％,87％,83％.当产甲烷相负荷升至4kgVS·m-3d-1时,由于进入产甲烷相的有机酸含量迅速增加,造成了有机酸的积累,pH值降至6.8以下,系统产气性能受到抑制,负荷产气量和VS去除率分别降至0.51 m3·kg-1VS和76％.研究发现：中试规模下,餐厨和果蔬混合厌氧消化在低负荷下可有效避免有机酸的积累,得到较高的沼气产量;高负荷下系统稳定性被破坏,导致沼气产量大幅降低.

Great economic growth and rapid urbanization have been achieved in recent years in China,which brings up the problem of food waste （FW） and fruit/vegetable waste （FVW） disposal in most of Chinese megacities.Two-phase anaerobic co-digestion of FW and FVW were investigated with pilot-scale reactors in this paper.FW and FVW were blended with the ratio of 8∶5.The result showed that,when the organic loading rate（OLR） of methanogenic reactors were 1,2 and 3 kgVS · m-3 d-1,the biogas yield reached 0.97,0.78,0.72 m3 · kgVS-1 with VS reduction rates of 84％,87％ and 83％ respectively.As OLR increased to its limitation,that was 4 kgVS · m-3d-1 in this system,the biogas yield reduced to 0.51 m3 · kgVS-1and VS reduction rates to 76％ owing to the accumulation of volatile fatty acid （VFA）.It was showed that anaerobic digestion of FW and FVW mixed waste could operate very well when OLR were not too high.Higher acidification risk could occurred when the OLR exceeded 4 kgVS · m-3d-1,