Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
Chemosphere. 2024 Oct;365:143371. doi: 10.1016/j.chemosphere.2024.143371. Epub 2024 Sep 19.
Perfluorooctanoic acid is an emerging pollutant with exceptional resistance to degradation and detrimental environmental and health impacts. Conventional physical and chemical processes for Perfluorooctanoic acid are either expensive or inefficient. This study developed an environmentally sustainable and cost-effective gravity-driven kappa-carrageenan (kC)-based hydrogel for perfluorooctanoic acid (PFOA) removal from synthetic and actual wastewater. Two kC filters were prepared by mixing activated carbon (AC) or vanillin (V) with the kC hydrogel to optimize the hydrogel selectivity and water permeability. Experimental work revealed that the PFOA rejection and water permeability increased with the AC and V concentrations in the kC hydrogel. Experiments also evaluated the impact of feed pH, PFOA concentration, hydrogel composition, and hydrogel thickness on its performance. Due to pore size shrinkage, the AC-kC and V-kC hydrogels achieved the highest PFOA rejection at pH 4, whereas the water flux decreased. Increasing the PFOA concentration reduced water flux and increased PFOA rejection. For 2 cm hydrogel thickness, the water flux of 3%kC-0.3%AC and 3%kC-3%V hydrogels was 25.6 LMH and 21.5 LMH, and the corresponding PFOA rejection was 86.9% for 3%kC-0.3%AC and 85.7% for 3%kC-3%V. Finally, the kC-0.3%AC hydrogel removed 81.1% of PFOA from wastewater of 179 mg/L initial concentration compared to 79.3% for the kC-3%V hydrogel. After three filtration cycles, the water flux decline of 3%kC-0.3%AC was less than 10%. The gravity dead-end kC hydrogel provides sustainable PFOA wastewater treatment with biodegradable and natural materials.
全氟辛酸是一种新兴的污染物，具有极强的抗降解能力，对环境和健康都有不利影响。传统的物理和化学方法处理全氟辛酸既昂贵又低效。本研究开发了一种环保且经济高效的重力驱动角叉菜胶（κC）基水凝胶，用于从合成和实际废水中去除全氟辛酸（PFOA）。通过将活性炭（AC）或香草醛（V）与κC水凝胶混合，制备了两种κC 过滤器，以优化水凝胶的选择性和水渗透性。实验结果表明，PFOA 的去除率和水渗透性随κC 水凝胶中 AC 和 V 的浓度增加而增加。实验还评估了进料 pH、PFOA 浓度、水凝胶组成和水凝胶厚度对其性能的影响。由于孔径收缩，AC-κC 和 V-κC 水凝胶在 pH 4 时达到了最高的 PFOA 去除率，而水通量降低。增加 PFOA 浓度会降低水通量并增加 PFOA 的去除率。对于 2 cm 水凝胶厚度，3%κC-0.3%AC 和 3%κC-3%V 水凝胶的水通量分别为 25.6 LMH 和 21.5 LMH，相应的 PFOA 去除率分别为 86.9%和 85.7%。最后，κC-0.3%AC 水凝胶从初始浓度为 179mg/L 的废水中去除了 81.1%的 PFOA，而 κC-3%V 水凝胶则去除了 79.3%。经过三个过滤循环，3%κC-0.3%AC 的水通量下降小于 10%。重力末端 κC 水凝胶提供了可持续的 PFOA 废水处理，使用的是可生物降解和天然材料。
