摘要
厌氧发酵产沼气作为主流的能源化技术,在有机废弃物的处理中发挥了重要作用。沼液作为沼气工程的主要副产物,由于其产量大、含水率高,在资源化利用过程中存在储存运输困难、难以及时消纳利用等问题,需要进行减量化处理。利用膜技术浓缩沼液可大幅降低沼液体积,产生大量淡水资源,同时获得含高浓度营养物质的浓缩液,已展现出广阔的应用前景。该研究归纳了厌氧发酵沼液的水质特性,综述了固液分离预处理,微滤(Microfiltration,MF)、超滤(Ultrafiltration,UF)、纳滤(Nanofiltration,NF)、反渗透(Reverse Osmosis,RO)、膜蒸馏(Membrane Distillation,MD)和减压膜蒸馏(Vacuum Membrane Distillation,VMD)等沼液膜浓缩技术,总结了各技术的处理原理及当前国内外研究进展,重点探讨了需解决的关键瓶颈问题,并对膜技术应用于沼气工程沼液减量化处理进行了展望与建议。
Membrane technology can be expected to concentrate lots of nutrients in small volumes in biogas slurry,and then transport specific nutrients into other agricultural areas to serve as fertilizer,thereby partially solving the problem of surplus biogas slurry in high-density livestock areas.This article presents a critical review of the state-of-art research on the application of membrane concentration for volume reduction of biogas slurry.There are some common features for the water quality of biogas slurry that produced by anaerobic digestion,including complex composition,high concentrations of suspended solids,organic matter,ammonia nitrogen,and salt.First,a general review was made on the solid-liquid separation technologies that used for biogas slurry pretreatment,together with the physical and chemical processes related to separation.The separation efficiencies of common techniques were ranked in order for the removal of particles:centrifugation>sedimentation>non-pressurized filtration>pressurized filtration.Treatment with flocculants before separation can significantly improve efficiency.Aluminum sulfate(Al2(SO4)3),polymeric aluminum chloride(PAC),ferric chloride(FeCl3),and calcium hydroxide(Ca(OH)2)have been proved to be highly efficient for the remove suspended solids.In the organic-polymers test,cationic polyacrylamide(PAM)was found to be the most efficient flocculants.Second,the liquid products from solid-liquid separation can further be treated by microfiltration or ultrafiltration,which can be used to remove bacterium,colloid components,and macromolecular substance.Compared with organic membrane,ceramic membrane can act as more efficient solid-liquid separator due to its large membrane flux,strong anti-pollution ability,and high chemical stability.Third,the nanofiltration or reverse osmosis can be used to concentrate the nutrients,including dissolved organic compounds,nitrogen,phosphorus,and potassium,particularly that the biogas slurry concentration in 15%–50%of the initial volume has been reported wi
作者
肖华
徐杏
周昕
朱晓明
周卫东
Xiao Hua;Xu Xing;Zhou Xin;Zhu Xiaoming;Zhou Weidong(Institute of Animal Husbandry and Veterinary Science,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2020年第14期226-236,共11页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金青年科学基金项目(31802110)
浙江省农业科学院2019年度青年人才培养项目(10102000319CC2301G/005/030)。
关键词
膜
发酵
废弃物
沼液
固液分离
膜浓缩
减量化
membranes
fermentation
wastes
biogas slurry
solid-liquid separation
membrane concentration
volume reduction
