正渗透膜生物反应器运行过程中溶质反渗对微生物群落的影响

以氯化钠为驱动溶质,采用正渗透膜生物反应器(forward osmosis membrane bioreactor,FOMBR)处理生活污水,考察其在运行过程中溶质反渗对系统内微生物群落造成的影响。稳定运行状态下的第7、14、20天的混合液污泥样品分别称为A1、A2、A3,并对微生物群落物种丰度、群落结构、聚类等进行了分析。结果表明:正渗透膜生物反应器运行20 d内水通量从9.5 L/(m^2·h)下降到8.17 L/(m^2·h),反向盐通量从29.52 g/(m^2·h)增加到35.06 g/(m^2·h)。整个运行过程中溶质反渗对微生物群落结构的变化有着一定的影响,3个样品共产生1496个OTUs,各样品间共享的OTUs不尽相同;溶质反渗对3种样品的微生物群落多样性、菌群丰度等影响较小。PCA分析中A2和A3两个样品距离更近,组成更相似,热图聚类分析再次验证A2与A3相似性更高;3个样品斜率较小且非常接近,并且A1和A3两个样品所含物种的丰富程度和均匀程度几乎一样;3个样品的活性污泥群落结构在门、纲、目分类水平上均具有较高的多样性,各分类水平上的菌群丰度存在一定的差异。

基于2种材质FO膜对OMBR运行特性影响的研究

通过水通量、反渗盐通量、污染物去除率考察了2种正渗透膜对OMBR运行特性的影响,并对膜污染特性进行了研究。结果表明,水通道蛋白(AQP)膜和醋酸纤维素(CTA)膜平均水通量分别为8.90、4.96 L/(m2·h),平均反渗盐通量分别为13.06、6.36 g/(m2·h)。CTA膜组氨氮、总氮和总磷的平均去除率分别为98.8%、94.1%和98.9%。AQP膜和CTA膜膜面污染中,C、O原子数占比分别为47.19%、35.13%和66.71%、24.38%。AQP膜污染蛋白质和多糖含量均高于CTA膜,平均荧光强度分别为72.98和79.49。

Multi-functional forward osmosis draw solutes for seawater desalination

Forward osmosis(FO), as one of the emerging desalination technologies, has the potential to produce fresh water from a variety of water sources by utilizing the osmotic pressure gradient across a semi-permeable membrane.Draw solution, as an essential component of any FO process, can extract water molecules from seawater or wastewater. An ideal draw solution should meet three essential requirements, namely high osmotic pressure, low reverse flux, and facile regeneration mechanism. The selection of proper draw solutes is especially critical for an energy-efficient FO process since the energy consumption mostly arises from the separation or regeneration of the draw solution. Recently, we developed a few multi-functional FO draw solutes, mainly aiming to enhance the FO water flux and to explore facile re-concentration methods. This review summarizes these draw solutes,including Na^+_- functionalized carbon quantum dots, thermoresponsive copolymers, hydrophilic magnetic nanoparticles, and thermoresponsive magnetic nanoparticles.