Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, South Korea.
Korea Biochar Research Center, Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, South Korea.
Water Res. 2019 Sep 1;160:217-227. doi: 10.1016/j.watres.2019.05.076. Epub 2019 May 23.
Forward osmosis (FO) has been adopted to treat complex wastewater such as landfill leachate due to its high rejection of organics. In this study, the in-line adsorptive process using biochar (BC) or powdered activated carbon (PAC) was applied to a cross flow FO system to enhance the mitigation of the FO membrane fouling from landfill leachate. The changes in the leachate composition along the treatments were tracked by excitation emission matrix-parallel factor analysis (EEM-PARAFAC) to identify tryptophan-like (C1), fulvic-like (C2), and humic-like (C3) components. After a single operation of FO, the C1 was found to be the main constituent responsible for membrane fouling irrespective of varying operation conditions regarding draw solute concentrations and flow rates. Both sorbents (i.e., BC and PAC) exhibited the preferential removal behavior towards C1 > C2 > C3, which was well supported by their individual adsorption isotherm model parameters. The addition of in-line adsorption treatment to FO resulted in substantial improvements in the filtered volume (>57%) and the flux recovery (>80%) compared to the single FO operation. Without chemical cleaning of membrane, the flux was fully recovered at a dose of 10 g/L BC or 0.3 g/L of PAC. A significant and negative correlation was found between the flux recovery and the C1 of the feed leachate or the corresponding spectral peak intensity (p < 0.05) for the integrated FO system, suggesting the potential of using on-line fluorescence monitoring for the performance of the integrated system in terms of fouling mitigation. This study provided a new insight into the effectiveness of BC or PAC adsorption as the in-line integration with an FO system for the targeted removal of FO membrane foulants in landfill leachate.
正向渗透（FO）因其对有机物的高截留率而被用于处理复杂废水，如垃圾渗滤液。在这项研究中，采用内置式生物炭（BC）或粉末活性炭（PAC）吸附工艺应用于错流 FO 系统，以增强减轻垃圾渗滤液对 FO 膜污染。通过激发发射矩阵平行因子分析（EEM-PARAFAC）跟踪渗滤液成分的变化，以鉴定色氨酸类（C1）、富里酸类（C2）和腐殖酸类（C3）成分。在 FO 的单次操作后，发现 C1 是导致膜污染的主要成分，而与不同的操作条件（例如，提取液浓度和流速）无关。两种吸附剂（即 BC 和 PAC）都表现出对 C1>C2>C3 的优先去除行为，这得到了它们各自吸附等温线模型参数的很好支持。与单独的 FO 操作相比，内置式吸附处理添加到 FO 中后，过滤体积（>57%）和通量恢复（>80%）都有了显著提高。在不进行膜化学清洗的情况下，在 10g/L BC 或 0.3g/L PAC 的剂量下，通量可完全恢复。在集成 FO 系统中，通量恢复与进料渗滤液中的 C1 或相应光谱峰强度之间存在显著的负相关关系（p<0.05），这表明在线荧光监测在评估集成系统的性能（减轻污染方面）具有潜在的应用前景。本研究为 BC 或 PAC 吸附作为 FO 系统的内置式集成提供了新的见解，以针对垃圾渗滤液中的 FO 膜污染物进行靶向去除。
