Improvement of anti-biofouling properties of hollow fiber membranes with bismuth-BAL chelates (BisBAL)

<p>In this study, hollow fiber membranes with and without bismuth dimercaptopropanol (Bis-BAL) additive were fabricated. Membranes were characterized in terms of permeability, surface properties, anti-biofouling and antibacterial properties. Membranes were operated in a lab-scale submerged membrane bioreactor (MBR). During the MBR operation, flux, chemical oxygen demand, volatile suspended solids and suspended solids were calculated for 30 days. Results showed that extracellular polymeric substance and soluble microbial product amounts were decreased in BisBAL-containing membranes. BisBAL-added membranes had the ability to inhibit the growth of <i>Escherichia coli.</i> BisBAL as an additive for membranes was found to be an effective, cheap alternative for enhancing anti-biofouling properties of the membranes.</p

Removal of endocrine-disrupting chemicals from textile industry effluents by nanofiltration

Textile finishing industry wastewaters contain micropollutants such as endocrine-disrupting chemicals in addition to the conventional pollutants since advanced manufacturing activities provide additional features to the textiles to make them shrink-proof, water-proof, wrinkle-proof, rot-proof, distasteful to moths, and mildew, flame-resistant, etc. Endocrine-disrupting chemicals can interfere with the endocrine system, exert endocrine-modulating behavior, and cause adverse health effects, even when exposed to low doses. Therefore, treatment of endocrine- disrupting chemicals is a major concern for textile finishing wastewaters since they cannot be completely removed by widely applied conventional treatment technologies; but rather by using membrane filtration, advanced oxidation, and adsorption technologies. This study aims to investigate the performance of nanofiltration membranes in the post-treatment of endocrine-disrupting chemicals in textile finishing wastewaters. A total of 299 chemicals that were identified as endocrine-disrupting chemicals present and/or likely to be present in surface waters of Turkey were monitored in a textile finishing wastewater, and their removal by nanofiltration was investigated. The experimental results showed that 10 of the 17 compounds determined in textile industry treatment plant effluent, including benzo (g,h,i) perylene, fluorene, phenanthrene, mono-2-ethylhexylphthalate, dicyclohexylphthalate, diethyl-phthalate, di-n-butylphthalate, octamethylcyclotetrasiloxane, mirex (perchloropentacyclodecane) and saccharin were treated below their limit of detection values with nanofiltration. On the other hand, it was determined that nanofiltration was not efficient for compounds such as naphthalene, mono-n-butylphthalate, and di-sec-octylphthalate

Biomimetic Approaches for Membrane Technologies

Membrane technology is the dominant process in water treatment. However, the operation cost of membranes cannot be decreased unless the amount of fouling, the "Achilles heel" of membranes, and energy consumed are cut. The high energy requirements in commercial nanofiltration, reverse osmosis and forward osmosis technologies lead researchers to develop new membrane designs having high flux values with high salt rejection values. The purpose of this review is to present the inadequacies of the membrane processes by considering studies related to fouling and energy minimization. In this respect, lipid bilayers, block copolymers, aquaporin Z proteins and aligned carbon nanotubes can be the base to build biomimetic membranes. Such studies are summarized due to their remarkable properties in fouling control. Furthermore, the review describes the membrane design strategies and points the limitations hindering commercialization. Additionally, it is hoped that this review will trigger further needed studies