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A number of factors have combined to put excessive pressure on the finite available freshwater resources. These include increasing population, rapid urbanization, industrialization, changed land pattern usage and land cover, change in the overall ecological system, and increased temperature and unscientific compromises in the extraction of water are at alarming threshold putting pressure on the finite available freshwater resources. As a result, many countries have been stressed or are at the verge of being stressed. The problem is worsened day by day by prolonged drought, unchecked discharge of untreated or partially treated wastewater to the freshwater reservoirs and lack of proper water quality control measures and management. Many initiatives such as Zero Liquid Discharge of industrial wastewater into freshwater bodies such as reservoirs, lakes, and ponds, and the use of recycled wastewater for irrigation and domestic purposes have started to be embraced as measures to put a check on the fast depleting freshwater resources for sustainable socio-economic development. The construction industry is the second largest consumer of freshwater just after agriculture. Concreting alone consumes, annually, over one trillion m3 of freshwater globally while the concept of the use of wastewater and/or recycled water in the concrete-making processes is yet to be adopted. Hence, this paper presents a general review of the current state of knowledge and practice on concrete production and curing using recycled wastewater from industrial, commercial, and domestic activities. An extensive review of the existing literature revealed that recycled water is fit for concrete production and curing purposes. The observations made are based on the assessment of wastewater quality parameters and their impacts on some selected concrete properties such as initial setting time and compressive strength. Due to scanty research on the impacts of varying concentrations of different ingredients in any questionable water on selected properties of reinforced concrete and its durability, thus, further research is recommended.

Municipal solid waste (MSW) generation rate is on the rise as it is estimated to reach 3,539 million tonnes by 2050 from the 1,999 million tonnes in 2015. The seasonal variations of the physio-chemical properties of the MSW among others exacerbates its management challenges. This study aimed to conduct in-depth investigations on the seasonal variations of physio-chemical properties of the MSW generated in Kabale Municipality, southwestern Uganda to inform sustainable MSW management systems. This study revealed that this MSW is majorly plastics, with concentrations of 21.45% and 26.94% in the dry and wet seasons, respectively, which presents a more recycling potential for these plastics in the wet season. The biodegradable MSW fraction (food, paper, cardboard and garden trimming wastes), which were 35.6% and 35.34% for the dry and wet seasons, respectively, supports energy recovery from the waste in the form of biogas, with a higher potential in the wet season as supported by its higher volatile solid content for the same of 48.92% as compared to that of the dry season of 34.92%. Based on these findings, it is recommended among others that the masses be sensitized on how to generate biogas from the biodegradable fraction of this MSW.

The continued use of vast amounts of gravel in maintenance of low volume traffic roads does not only depletes it, but also is un-sustainable in the medium to long term run compared to bituminous sealing of them using low cost materials. One of the materials required to achieve the later are chippings. In Uganda, only few kilometers of these roads can be sealed in a financial year due to low indicative planning figures for road maintenance and this makes hand crushing of the chippings possible as only a small quantity will be required. This leads to employment creation and protecting the environment from noise and dust pollution caused by machine blasting. Haulage distances for these chippings from the quarries to sites of application also impact considerably the cost of these low cost sealing projects. It is against the above background that hand crushed samples from Akia and Ngeta quarries were taken and analyzed for their suitability as surfacing materials for single surface dressing of low volume traffic roads. All the parameters analyzed were within the permissible limits.

Fly ash (FA) is a particulate matter consisting of finely divided, non-combustible particles obtained from the flue gases arising from combustion of coal, accounts for over 80% of the total ash produced during coal combustion. In 2018 alone, about 780 million tons of FA has been generated globally, of which voluminous quantity remained unutilized, hence dumped into the environment. This continued disposal of FA into the environment makes the heavy metals contained therein to move out in the leachate generated, polluting the soil, surface and ground water sources among others. In this study, 5 sets of leaching test columns were packed with an equal quantity of air dried fly ash samples and each of them leached with leachant of pH 5.87, 6.08, 6.41, 6.46 and 7.01 and eluate from each column collected at cumulative liquid to solid (L/S) ratios in l/kg of 0.1, 0.2, 0.5, 1.0 and 2.0. Analysis of the eluate for Copper (Cu), Selenium (Se), Zinc (Zn), Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr) and Arsenic (As), revealed that the concentrations of Se at Selenium L/S of 0.1 for leachant pH of 5.87, 6.41 and 7.01, exceeded the allowable limits for non-hazardous wastes disposal into the landfills.