Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, 6627, Antônio Carlos Avenue, Campus Pampulha, Belo Horizonte, MG, Brazil.
Department of Chemical Engineering, Pontifícia Universidade Católica de Minas Gerais, 6627, Dom José Gaspar Street, 500, Belo Horizonte, MG, Brazil.
Chemosphere. 2022 Nov;306:135591. doi: 10.1016/j.chemosphere.2022.135591. Epub 2022 Jul 4.
Despite the widespread use of membrane separation processes for water treatment, operation costs and fouling still restrict their application. Costs can be overcome by recycled membranes whereas fouling can be mitigated by membrane modification. In this work, the performance of recycled reverse osmosis membranes modified by greener titanium dioxide (TiO) and graphene oxide (GO) in different modification routes were investigated and compared. The use of recycled membranes as a support acted more than a strategy for costs reduction, but also as an alternative for solid waste reduction. Low adhesion of nanoparticulate materials to the membrane surfaces were verified in depositions by self-assembly, whereas filtration and modification with dopamine generated membranes with well adhered and homogeneous layers. Considering the stability, permeability, and rejection efficiency of dyes as model substrates, the membranes modified with the aid of dopamine-TiO-GO were the most promising. The nanomaterials increased the membrane hydrophilicity and formed a hydrated layer that repels the organic contaminants and reduces fouling. Besides membrane rejection, adsorption (contribution: ∼10%) and photocatalysis (contribution: ∼20%) were additional mechanisms for pollutants removal by the modified membranes. The photocatalytic membrane modified with dopamine-TiO-GO was furthermore evaluated for the removal of six different pharmaceutical active compounds (PhACs), noticing gains in terms of removal efficiency (up to 95.7%) and fouling mitigation for the modified membrane compared to the original membranes. The photocatalytic activity still contributed to a simultaneous degradation of PhACs avoiding the generation of a concentrated stream for further disposal.
尽管膜分离过程在水处理中得到了广泛应用，但运行成本和结垢仍然限制了它们的应用。通过回收膜可以克服成本问题，而通过膜改性可以减轻结垢问题。在这项工作中，研究并比较了通过更环保的二氧化钛（TiO）和氧化石墨烯（GO）以不同改性路线对回收反渗透膜性能的影响。回收膜的使用不仅是降低成本的策略，还可以作为减少固体废物的替代方案。自组装沉积中验证了纳米颗粒材料在膜表面的低附着力，而使用多巴胺进行过滤和改性则生成了附着良好且均匀的层的膜。考虑到染料作为模型底物的稳定性、渗透性和截留效率，在多巴胺-TiO-GO 辅助下改性的膜最有前景。纳米材料提高了膜的亲水性，并形成了水合层，排斥有机污染物并减少结垢。除了膜截留外，吸附（贡献：约 10%）和光催化（贡献：约 20%）也是改性膜去除污染物的额外机制。此外，还对多巴胺-TiO-GO 改性的光催化膜进行了去除六种不同药物活性化合物（PhACs）的评估，与原始膜相比，改性膜在去除效率（高达 95.7%）和结垢缓解方面都有了提高。光催化活性还有助于同时降解 PhACs，避免产生浓缩流以进一步处理。
