果蔬垃圾厌氧发酵沼液超滤预处理工艺研究

Study on Ultrafiltration Pretreatment of Biogas Slurry from Anaerobic Fermentation of Fruit and Vegetable Wastes

果蔬垃圾经破损、压榨和厌氧发酵处理后会产生沼液,其含有高浓度的SS、COD和TN,多采用生化处理工艺,处理难度较大。采用“格栅+串螺+超滤”作为沼液预处理工艺,考察超滤膜对沼液的处理效果及系统运行稳定性。结果表明,超滤膜对SS的去除率达到99%,对COD和TN的去除率在40%以上,明显改善了生化系统的进水水质;初始产水流量为88 mL/min,运行方式为工作5 min+停歇1 min,有助于减轻膜的污染速度;增加反洗和冲洗程序可以保证产水流量的稳定,在18 min反洗一次和2 h冲洗一次的措施下,系统可以稳定运行12 h。

Biogas slurry will be produced after the waste of fruits and vegetables is damaged,pressed and anaerobicly fermented,which contains high concentration of SS,COD and TN.At present,biogas slurry is mostly treated by biochemical process which is difficult to deal with.This research adopted“grille+series screw+ultrafiltration”as the biogas slurry pretreatment process,the treatment effect of ultrafiltration membrane on biogas slurry and the operation stability of the system are investigated.The results show that the removal rate of SS by ultrafiltration membrane is 99%,the COD and total nitrogen removal rate are more than 40%,significantly improve the biochemical system of feed water quality.The initial production water flow rate is 88 mL/min,and the operation mode is 5 minutes work+1 min stop,which helps to reduce the pollution speed of the membrane.The addition of backwash and rinsing procedures can ensure the stability of the production water flow,and the system can run stably for 12 h under the measures of 18 min backwash and 2 h rinse.