规模化养鸡场沼气工程沼液膜分离处理效果对比

针对规模化养鸡场沼气工程产生的大量沼液难以消纳的问题，建立工程化膜分离中试装置，研究膜工艺对鸡粪沼液COD、氨氮及养分等指标的分离效果。结果表明，“袋滤+超滤+纳滤+反渗透”工艺组合对COD的截留率为96.5%，对氨氮的截留率为63.8%。“袋滤+超滤+两级反渗透”工艺组合，终端透过液的COD为66 mgL，COD截留率达99.2%，透过液氨氮为530 mgL，氨氮截留率达82.4%。“超滤+两级反渗透”对鸡粪沼液的处理效果优于“超滤+纳滤+反渗透”。反渗透对沼液中腐殖酸和氨基酸具有一定的浓缩效果，反渗透浓液可进一步配置液体肥料或开发其他用途。 

Comparison of Membrane Separation Effects on Treating Liquid Digestate from Large-scale Chicken Farm Biogas Engineering

Considering difficulty of treating large amounts of liquid digestate from large-scale chicken farm biogas engineering，pilot scale integrated membrane separation equipment was developed.The separation effect of membrane technology on the reduction of COD，ammonia nitrogen and nutrients in the liquid digestate was studied.Results showed that process combination of‘bag filter+ultrafiltration（UF）+nanofiltration（NF）+reverse osmosis（RO）’achieved the COD rejection rate of 96.5%，and the ammonia nitrogen rejection rate of 63.8%.Through process combination of‘bag filter+UF+two-stage RO’，COD in the final permeate was reduced to 66 mgL with COD rejection rate up to 99.2%，while ammonia nitrogen in the final permeate was reduced to 530 mgL with ammonia nitrogen rejection rate of 82.4%.Process of‘UF+two-stage RO’achieved better separation effect on chicken manure liquid digestate than‘UF+NF+RO’.Humic acid and amino acid in the liquid digestate was concentrated under the action of RO.RO concentrate could be further used for production of liquid fertilizer or for other development and utilization.