Hend Omar Mohamed

A novel strategy for enhancing the electrospun PVDF support layer of thin-film composite forward osmosis membranes

A simple and novel treatment methodology is introduced to produce PVDF-based thin-film composite forward osmosis (TFC-FO) electrospun membranes for enhanced desalination performance. The proposed treatment strategy is based on improving the surface properties of the PVDF electrospun nanofiber support layer using triethylamine (TEA). The results indicated that this strategy enhanced the interfacial polymerization step by overcoming the hydrophobicity feature dilemma of the PVDF support layer. As an FO membrane, the characterization of the modified membrane shows a distinct decrease in the structure parameter of the support layer by 67%, which mitigates the adverse effect of the internal concentration polarization (ICP) by 45%. Moreover, the performance of the modified TFC-FO membrane exhibited a high water flux, approximately 68 LMH and low reverse salt flux, about 2 g m−2 h−1 at 2 M NaCl draw solution, with >99.5% salt rejection. Overall, the introduced modification technique has the advantages of being inexpensive, easy to implement, and appropriate for commercial membranes.

A novel approach to developing a reusable marine macro-algae adsorbent with chitosan and ferric oxide for simultaneous efficient heavy metal removal and easy magnetic separation

Chitosan modified magnetic kelp biochar (Chi-KBm) was successfully synthesized for efficient removal of heavy metals (Cu2+) from wastewater. Interestingly, the characterization results indicated that Chi-KBm showed 6 times higher surface area (6.17 m2/g) than the pristine magnetic kelp biochar KBm (0.97 m2/g). In addition, new functional groups, such as NH and CN group, have been created on the surface of biochar as a result of chitosan modification process, which in turns led to improve the Cu2+ adsorption capacity. The effect of pH and chitosan loading on heavy metal adsorption, and competition reaction of different metal ions adsorption were also investigated. Chi-KBm exhibited a separation efficiency of more than 99.8%, which allows to recovery and reusability of the adsorbent material and heavy metals simultaneously. Overall, this study highlighted the Chi-KBm is a promise adsorbent for heavy metal removal without sacrificing of the separation ability using magnetism.

Electrodepositing technique for improving the performance of crystalline and amorphous carbonaceous anodes for MFCs

The properties and cost of anode materials are essential factors affecting the microbial fuel cell (MFC) performance. Therefore, in this study, an electrodeposition technique is presented as a cheap, easy, efficient, and straightforward strategy to increase the exoelectroactive bacterial adhesion and improve the surface properties of the crystalline and amorphous carbonaceous materials for use as anodes in the microbial fuel cells enriched with unconditioned industrial wastewater. Individually, the surfaces of commercial activated carbon AC (amorphous), carbon paper CP (crystalline), and carbon cloth (CC) were modified by an iron electrodeposition technique. In air-cathode microbial fuel cells, the suggested modification strategy strongly enhanced the power generation as the observed increase was 18.5%, 47.5% and 65.8% for the activated carbon, carbon cloth and carbon paper, respectively. Moreover, the coulombic efficiency (CE) is increased after iron electrodeposition modification process to reach up to 80% in case of treated activated carbon anode. Overall, the results confirmed the successful electrodeposition of iron, as an effective, simple and cheap surface treatment technique, is more efficient in the crystalline materials as compared to the amorphous materials.