Dip coating and Layer-by-layer have been proven as effective deposition methods. Uncrosslinked and PPD crosslinked GO membranes have been successfully fabricated. Crosslinker impact is significant in enhanced membrane separation performance. Up to 100% MB contaminant removal was achieved for crosslinked membranes. PPD-GO crosslinked membranes are suitable to reuse for multiple cycles.

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The augmentation of research in graphene based thin films has been of great interest to various current industrial stakeholders. This is mainly due to the wide scope of films applications, ranging from nanoelectronics to separation membranes. Therefore, establishing a relation between graphene based thin film key characteristics and the fabrication operating conditions is of high significance. This study entails the successful fabrication of controlled-thickness crosslinked graphene oxide (GO) thin films on inexpensive silicon-based glass slide substrates. The method of film fabrication used is the dip-assisted layer-by-layer assembly, which has an added advantage of step-control of thin film thickness, good film uniformity and continuity.

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One of the critical steps in the treatment of raw water for human consumption is clarification. It encompasses coagulation and flocculation to reduce the concentration of suspended solids and in the process produces a semi-solid slurry called water treatment sludge (WTS). It is necessary to characterize and find economic and environmentally friendly ways to utilize the WTS. The WTS used in this work was characterized and contained aluminum (Al) (20.3% Al2O3) and iron (Fe) (5.28% Fe2O3) making it suitable for the development of a coagulant. A less energy-intensive way, through atmospheric acid leaching of WTS, was developed to extract Al and Fe for use as a coagulant. The sulphuric acid concentration and solid loading that gave the highest Al concentration were determined to be 3 N and 5 g/100 mL, respectively. Turbidity reduction achieved with the developed coagulant ranged from 91 to 99% and was higher than that obtained in related studies due to the higher concentrations of Al and Fe in the WTS used in this study. Since the coagulant was very acidic, it was co-dosed with calcium oxide at 10 g/L of water to adjust the pH of the final water to allowable pH values for potable water (6.5–9.5).