Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Glass and Ceramic Research Institute, Kolkata, India.
Membrane and Separation Technology Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata, 700032, India.
Environ Sci Pollut Res Int. 2022 Jul;29(32):48620-48637. doi: 10.1007/s11356-022-19258-z. Epub 2022 Feb 23.
The present study evaluates the performance of an indigenously developed ceramic ultrafiltration (UF) membrane in a lab-scale membrane bioreactor (MBR) process to treat real tannery effluent with varying organic loading (1500-6000 mg/L). UF membrane was prepared by the coating of bentonite clay on tubular clay-alumina macroporous support. The membrane surface was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, BET adsorption-desorption, contact angle measurement, and atomic force microscopy. In the side-stream MBR process, sewage sludge from a local sewage treatment plant was used as an activated sludge source with a constant sludge retention time of 30 days. Membrane filtration was performed in cross-flow mode using a single-channel membrane module. Artificial neural network (ANN) modeling tool was used to analyze the influence of various independent input variables, namely, the hydraulic retention time (4-10 h), mixed liquor suspended solid (MLSS) concentration (2-8 g/L), and influent COD concentration (1500-6000 mg/L) on COD removal (%) with feed-forward backpropagation method. Membrane study was done at a transmembrane pressure of 4.3 bar and feed flow rate of 7.5 L/min to observe the flux declination and fouling of the UF membrane with time. Average COD and BOD concentrations obtained in the treated effluent were 147.56 and 31 mg/L, respectively, and chromium concentration was < 0.1 mg/L; thus, treated effluent quality was found to be suitable for industrial recycling purposes apart from the safe environmental discharge. An in-depth study was undertaken to understand the removal mechanism in the MBR process, nature and extent of membrane fouling, changes in the morphology of the UF membrane, surface wettability, and surface topology by detailed surface characterization of the membrane pre- and post-filtration.
本研究评估了一种国产陶瓷超滤（UF）膜在实验室规模的膜生物反应器（MBR）工艺中处理不同有机负荷（1500-6000mg/L）实际制革废水的性能。UF 膜是通过在管状粘土-氧化铝大孔载体上涂覆膨润土粘土制备的。通过扫描电子显微镜、傅里叶变换红外光谱、X 射线衍射、X 射线光电子能谱、BET 吸附-解吸、接触角测量和原子力显微镜对膜表面进行了表征。在侧流 MBR 工艺中，使用当地污水处理厂的污水污泥作为活性污泥源，污泥停留时间保持在 30 天。膜过滤采用单通道膜模块在错流模式下进行。人工神经网络（ANN）建模工具用于分析各种独立输入变量（水力停留时间（4-10 小时）、混合液悬浮固体（MLSS）浓度（2-8g/L）和进水 COD 浓度（1500-6000mg/L）对 COD 去除率（%）的影响，采用前馈反向传播方法。在跨膜压力为 4.3 巴和进料流速为 7.5L/min 的条件下进行膜研究，以观察 UF 膜随时间的通量衰减和污染情况。处理后废水中的平均 COD 和 BOD 浓度分别为 147.56mg/L 和 31mg/L，铬浓度<0.1mg/L；因此，处理后的废水质量除了安全环境排放外，还适合工业回收利用。进行了深入研究，以了解 MBR 工艺中的去除机制、膜污染的性质和程度、UF 膜形貌变化、表面润湿性和表面拓扑结构，对膜过滤前后进行了详细的表面表征。
