This research focused on the integration of waste plastic into concrete in a bid to restrain water ingress when exposed to water. Polyethylene water sachet (PWS) was the source of waste plastic used. Waste plastic concrete treatments were designed and cast successfully with percentage waste plastic contents of 0, 0.25, 0.50, 0.75 and 1.00. It also involved a constant water/cement ratio of 0.45, a mix design of 1:2:4 and 2% by 342.85kg cement weight of superplasticizer. Twenty cubes, 20 beams and 45 cylindrical specimens were cast for compressive, fl exural, split tensile and water absorption tests respectively at 28 days of curing. Waste plastic treatments of 0.5% and 0.75% contents had the highest compressive strength. Water absorption characteristics of waste plastic concrete dropped with increasing plastic waste content to 0.75% after which further increase gave undesirable effects. Optimum water absorption (impermeability) were observed between 0.50% and 0.75% waste plastic content. Waste plastic concrete of 0.75% content with compressive strength and water absorption values of 21.19MPa and 0.22% respectively met the requirements of ASTM C55-11, ASTM C139-11 and CP 102. Waste plastic concrete showed desirable characteristics for potential use in the built environment.

Wine is one of the most ancient commodities in the world. The critical residues from the wine industry are grape leaves, stems, grape pomace, grape seeds, yeast lees, tartrate, and wastewater. The indiscriminate disposal of produced wastewater has adverse environmental and health consequences. Nevertheless, winery effluent has substantial prospects as an energy source. Hence, this paper aims to briefly showcase the potential of energy generation from wastewater in the wine industry through anaerobic digestion. From literature and statistical records, in 2018, the cultivation of grapes in Moldova covered about 126,873 ha of land and produced 730,171 t of grapes, with over 24% pressed for wine production. Consequently, the industry released over 6 billion litres of wastewater. Therefore, by anaerobic digestion of this effluent, there is a potential for the wine industry to produce 459,166 MWh of electricity annually to satisfy nearly 287,000 people. This potential represents a very important step towards energy self-sufficiency of the wine industry and a contribution to the sustainable development goals concerning wastewater, energy and sanitation.

This article is the result of a systematic review of published life cycle assessment (LCA) studies on water and wastewater treatment in Africa. After applying the search and selection criteria, 32 observations for energy use were included and 20 for the global warming potential (GWP) and the eutrophication potential (EP). The dependent variables were categorized by technical, method, and typology factors. The meta‐regression model aligned with the descriptive statistics on the variation of the dependent variables due to water source but not location. Regarding energy use, GWP, and EP, the water source and the study location had the most significant influence in contrast to the life cycle impact assessment method. There is a need for more such LCA studies in Central and Western parts of Africa.