摘要
剩余污泥中胞外聚合物(EPS)具有巨大的回收价值。然而,回收的EPS溶液含水率接近100%,其浓缩脱水是亟待解决的关键问题。正渗透(FO)膜分离具有膜污染小、浓缩率高、耐高浓度等特点,已成为新兴的节能脱水技术。提出了一种新型的死端FO浓缩方式,调查了模拟EPS(藻酸钠)的正渗透脱水行为。结果显示:FO膜活性层朝向料液侧时水通量下降速率小;类似于外加压力驱动,扫流模式可以减轻FO膜污染,提高水通量;为防止FO膜的拉伸变形,隔板需进行合理设计(如适宜的开孔率),以缓解水通量的下降;不同于外加压力驱动,尽管Ca^2+也可减轻膜污染,但效果有限。
Extracellular polymeric substances(EPSs)in excess sludge have great recycling value.However,the solutions of recycled EPSs afford the moisture contents of nearly 100%and therefore the dehydration of these solutions is an urgent problem.Forward osmosis(FO)membrane separation having advanteges of low membrane fouling,high concentration efficiency,and high concentration resistance,has become a novel low-energy dewatering technology.A novel dead-end FO concentration method was proposed and the FO dewatering of simulated EPS(sodium alginate)was investigated.The results showed that the decline rate of flux deceased when the active layer of FO membrane was towards the feed side;similar to external pressure drive,the cross flow mode could reduce FO membrane fouling and improve flux;the spacer,which was used for preventing the tensile deformation of the FO membrane,should be designed reasonably such as the appropriate holed ratio to reduce the flux decline;the mitigation of FO membrane fouling with Ca^2+addition was insignificant although it was reduced,different from the external pressure drive.
作者
曹达啟
孙秀珍
方晓敏
靳景宜
杨晓璇
郝晓地
CAO Da-qi;SUN Xiu-zhen;FANG Xiao-min;JIN Jing-yi;YANG Xiao-xuan;HAO Xiao-di(Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies/Key Laboratory of Urban Stormwater System and Water Environment,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)
出处
《环境工程》
CAS
CSCD
北大核心
2020年第8期71-75,共5页
Environmental Engineering
基金
北京“未来城市设计高精尖中心”项目
北京市高水平创新团队“传统村落保护与居民建筑功能提升关键技术研究项目”。
关键词
胞外聚合物
回收
正渗透
膜污染
藻酸钠
extracellular polymeric substance
recovery
forward osmosis
membrane fouling
sodium alginate
