膜处理技术应用于沼液浓缩的研究进展

摘要

沼液富含营养元素,是非常有回收价值的一种有机肥料资源.当前,沼液存在体积庞大,运输、贮存困难,不能及时消纳利用的问题.利用膜技术对沼液进行浓缩,因浓缩液具有营养物质不发生改变、体积小、浓度高等特点,已经展现出广阔的应用前景.文章综述了包括超滤膜技术(UF)、纳滤膜技术(NF)、反渗透膜技术(RO)以及新兴的正渗透膜技术(FO)在内的沼液浓缩膜技术,概述了各技术的分离原理及当前国内外研究进展,重点探讨了RO及FO技术在沼液浓缩过程中的优势和存在的关键问题,并对膜技术应用于沼液浓缩进行了前景展望与建议.%Biogas slurry is a recoverable fertilizer resource which contains large amounts of organic matters and nutrient elements.However,the consumption and application of biogas slurry was not always in time or effective due to its huge volume and hard-to-transport or store.The concentration of biogas slurry using membrane technology is a promising way to dispose this resource.The property and composition of the nutrients in biogas slurry were remained after concentrating with membrane,and the concentrated slurry possessed smaller volume and higher nutrient concentration.Membrane concentrating for biogas slurry showed a broad application prospect.This paper reviewed several membrane concentration technologies for biogas slurry,including the ultrafiltration (UF) membrane technology,nanofiltration (NF) membrane technology,reverse osmosis (RO) membrane technology and the newly developed forward osmosis (FO) membrane technology.The concentration principles of these membrane technologies were summarized,and provided an overview of domestic and abroad research advances.Some advantages and key problems in RO and FO membrane technology for biogas slurry concentration were emphatically discussed.Finally,bright prospect and future research directions were put forward in this paper.