Increased affordability, smaller footprint, and high permeability quality that meets stringent water quality standards have accelerated the uptake of membranes in water treatment. Moreover, low pressure, gravity-based microfiltration (MF) and ultrafiltration (UF) membranes eliminate the use of electricity and pumps. However, MF and UF processes remove contaminants by size exclusion, based on membrane pore size. This limits their application in the removal of smaller matter or even harmful microorganisms. There is a need to enhance the membrane properties to meet needs such as adequate disinfection, flux amelioration, and reduced membrane fouling. To achieve these, the incorporation of nanoparticles with unique properties in membranes has potential. Herein, we review recent developments in the impregnation of polymeric and ceramic microfiltration and ultrafiltration membranes with silver nanoparticles that are applied in water treatment. We critically evaluated the potential of these membranes in enhanced antifouling, increased permeability quality and flux compared to uncoated membranes. Despite the intensive research in this area, most studies have been performed at laboratory scale for short periods of time. There is a need for studies that assess the long-term stability of the nanoparticles and the impact on disinfection and antifouling performance. These challenges are addressed in this study and future directions.

The study investigates the influence of process parameters on the effectiveness of ozonation in the removal of organic micro-pollutants from wastewater. Primary and secondary municipal wastewater containing phenol was treated. The effect of operating parameters such as initial pH, ozone dosage, and initial contaminant concentration was studied. An increase in contaminant decomposition with pH (3–11) was observed. The contaminant removal efficiencies increased with an increase in ozone dose rate (5.5–36.17 mg L−1 min−1). Furthermore, the ultraviolet absorbance (UV 254 nm) of the wastewater decreased during ozonation indicating the breakdown of complex organic compounds into low molecular weight organics. Along the reaction, the pH of wastewater decreased from 11 to around 8.5 due to the formation of intermediate acidic species. Moreover, the biodegradability of wastewaters, measured as biological and chemical oxygen demand (BOD5/COD), increased from 0.22 to 0.53. High ozone utilization efficiencies of up to 95% were attained thereby increasing the process efficiency; and they were dependent on the ozone dosage and pH of solution. Ozonation of secondary wastewater attained the South African water standards in terms of COD required for wastewater discharge and dissolved organic carbon in drinking water and increased significantly the biodegradability of primary wastewater.

This paper carried out a comparative review on the current trends in the conversion of palm oil waste into value-adding products by the Cameroonian and Malaysian palm sectors/researchers. Trends like composting, composite, pulping, mushroom cultivation, pyrolysis, aerobic and anaerobic digestion of palm biomass were studied as means to reduce the bulk, and to curb emissions of Greenhouse gas while producing value. Base on this research, limited works has been done on the conversion of palm biomass into value in Cameroon, whereas Malaysian palm researchers have employed all of these techniques and producing values from them. It was discovered that the various conversion process have different degree of feasibility and sustainability, and the end-products have different applications. Conversion process like pyrolysis is relatively faster, it could take just a few minute and the end-product which is biofuel have a wide range of applications; in contrast to composting which could take up to 180 days to mature and the end-product is limited to fertilizer. This research aims to sensitize the palm sector in Cameroon to the various processes that can be applied to sustainably manage palm waste. A priority table was also developed based on the feasibility and sustainability of the various conversion processes to serve as a guide towards sustainable waste management in the agro-industrial palm sector in Cameroon and a step towards industrialization.