Yue Caide, Dong Hongmin, Chen Yongxing, Shang Bin, Wang Yi, Wang Shunli, Zhu Zhiping
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Key Laboratory of Energy Conservation and Waste Treatment of Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing 100081, China.
Membranes (Basel). 2021 Mar 3;11(3):179. doi: 10.3390/membranes11030179.
Ultrafiltration (UF) can effectively remove large particles, suspended solids, and colloidal substances from anaerobic digestate. However, membrane fouling is a technical challenge in the purification of the digestate by UF. In this study, polyethersulfone (PES) membranes with four pore sizes (50.0, 20.0, 10.0 and 5.0 kDa) were employed to filter anaerobic digestate from swine manure. The effects of temperature, transmembrane pressure (TMP), and cross-flow velocity (CFV) on flux were investigated. The purification effects and fouling characteristics of the four membranes were analyzed. The results revealed that the increase of temperature and CFV can effectively promote UF separation efficiency, but as the TMP exceeded 3.0 bar, the flux increase rates of the four membranes were almost zero. The larger membrane pore size caused the faster flux increase with the increase in pressure. During the batch experiment, the 20.0 kDa membrane showed the lowest flux maintenance ability, while the 5.0 kDa showed the highest ability due to the smaller pore size. All four membranes can effectively remove tetracyclines residues. Elements C, O, and S were the major membrane foulant elements. The dominant bacteria orders of membrane fouling were , and . Compared with tap water and citric acid, the membrane cleaning by NaOH and NaClO showed higher flux recovery rates. The 50.0 kDa membrane achieved the best cleaning effects under all cleaning methods.
超滤（UF）能够有效去除厌氧消化液中的大颗粒、悬浮固体和胶体物质。然而，膜污染是利用超滤净化消化液过程中的一项技术挑战。在本研究中，使用了四种孔径（50.0、20.0、10.0和5.0 kDa）的聚醚砜（PES）膜来过滤猪粪厌氧消化液。研究了温度、跨膜压力（TMP）和错流速度（CFV）对通量的影响。分析了四种膜的净化效果和污染特性。结果表明，温度和CFV的升高可有效提高超滤分离效率，但当TMP超过3.0 bar时，四种膜的通量增加率几乎为零。膜孔径越大，压力升高时通量增加越快。在间歇实验中，20.0 kDa的膜通量维持能力最低，而5.0 kDa的膜由于孔径较小，通量维持能力最高。所有四种膜都能有效去除四环素残留。元素C、O和S是主要的膜污染元素。膜污染的主要细菌目为 、 和 。与自来水和柠檬酸相比，用NaOH和NaClO清洗膜显示出更高的通量恢复率。在所有清洗方法下，50.0 kDa的膜清洗效果最佳。
