Abstract: In this study, activated biochar from municipal sewage sludge was used for the treatment of sewage water. The sewage physicochemical parameters were measured before and after bio filtration with biochar applying the principle of adsorption using the standard methods. Biochar with 500 m2/g surface area at a loading of 2.5 g/L was employed. A reduction of more than 75% was observed for the total nitrogen, biological oxygen demand, chemical oxygen demand, total solids, electrical cond...
Abstract: This paper is a case study review of the timber waste problem and solutions that have been proffered in the Manicaland region of Zimbabwe. The study was conducted through primary data collected during site visits and a review of literature reports on the area. It revealed the absence of up to date quantitative and spatial data on timber waste, with literature reporting at least 70,000 tonnes per annum of sawmill waste. Most of the offcuts and chips are utilized at commercial sawmil...
Abstract: The production of copper bears both viable product and by product know as slag which is a challenge to dispose and poses a problem to the environment. BCL holds copper slag is seen as waste which is iron - opulent containing heavy metals which can seep into ground water and affect environment. These metal accumulate in millions of tonnes year after year posing as a threat to the environment and need to be managed to avoid them being harmful. This paper explores metallurgical ways o...
Abstract: The recovery of precious metals like gold is increasing each day due to its high market prices along with diverse applications. Bio-sorption represents a biotechnological innovation as well as a cost effective and excellent tool for recovery of precious metals from aqueous solutions. This study offers an overview of a recent scenario of bio-sorption studies carried out on the use of some promising bio-sorbents which could serve as an economical means for recovering gold for small s...
Abstract: The tyre industry in Botswana produces and sells thousands of tyres annually generating volumes of waste tyres which contribute towards the country’s waste management challenges. At the end of their useful life, most tyres end up at waste dumping sites while a small fraction is recycled or reused, posing a health, safety and environmental hazard. The same desirable that make tyres, such as immunity to biodegradation, chemical reagents and photochemical decomposition tend to make ...
Abstract: Plastics have remained the material of choice, and after serving their intended purpose, a large proportion ends up in the environment where they persist for centuries. The packaging industry is the largest and growing consumer of synthetic plastics derived from fossil fuels. Food packaging plastics account for the bulk of plastic waste that are polluting the environment. Additionally, given the fact that petroleum reserves are finite and facing depletion, there is a need for the d...
Abstract: Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks ...
Abstract: Water quality index has been used in various researches for the assessment of water quality for various uses and discharges into the environment. The purpose of this study was to determine the water quality index of the effluent from waste stabilisation ponds and 400 m beyond discharge point. This was achieved by evaluating concentrations of seven parameters from soil, eleven physiochemical parameters from effluent and four microbiological parameters. Corresponding water quality in...
Abstract: Ammunition used for military training and exercises has been found to contain high content of lead (Pb). The Pb present in the ammunition projectiles undergoes an array of transformation and weathering reactions when it reaches the shooting range soils. Seven military shooting ranges in the eastern and northern Botswana were used for this study. Soil samples were collected at each of the seven shooting ranges at the berm (stop butt), target line, 50 and 100 m from the berm. Pb conc...
Abstract: Lepidopteran stemborers are key destructive insect pests of cereal crops in sub-Saharan Africa with the indigenous noctuids Busseola fusca (Fuller) and Sesamia calamistis Hampson and the exotic crambid Chilo partellus Swinhoe accounting for ~5-75% of potential cereal crop yield losses. The main larval endoparasitoids comprising, indigenous Cotesia sesamiae and exotic Cotesia flavipes Cameron contribute to a significant extent in managing these economic herbivorous insect pests. How...
Abstract: Plastic adjustments of physiological tolerance to a particular stressor can result in fitness benefits for resistance that might manifest not only in that same environment, but might also be advantageous when faced with alternative environmental stressors, a phenomenon termed cross-tolerance. The nature and magnitude of cross-tolerance responses can provide important insights into the underlying genetic architecture, potential constraints on, or versatility of, an organism’s stre...
Abstract: Issues on environmental soil quality continue to attract much global attention. Domestic wastewater is a potential source of contaminants capable of degrading the soil environment. This study reports the accumulative effects of 21 years (1995 – 2016) of treated wastewater discharge on heavy metal concentration levels in the proximal environment of Palapye wastewater treatment Plant (PWTP), Central Botswana. Soil samples were collected from eight geo-referenced pedons: four situat...
Abstract: Vegetation plays a vital and important role in regulating climate, water balance and energy. This research examines vegetation variability and degradation in semi-arid Palapye, eastern Botswana. These were assessed over an 18 year period (1998 to 2016) using Remote Sensing based Normalized Difference Vegetation Index (NDVI) time series data. NDVI has been widely used as an indicator of vegetation growth because it measures the amount of plant greenness from the spectral responses m...
Abstract: The aim of this thesis was to identify an abundant, easily available, cheap and environmentally friendly waste material(s) in our locality, Botswana, that could be valorized (rejuvenated) by subjecting it to a simple green procedure, then apply as an adsorbent to clean wastewater through the removal or reduction of ions Co, Ni, Zn, Cu, Hg, Cr, Ag, Fe, Pb, Al, As, Cd, Sn, Ti, Mg, F-, Cl-, SO42-, PO43-, NO2-, BrO3-, and NO3- that usually exist in wastewater. After an extensive search...
Abstract: In Botswana crop production has been the most vulnerable component of the agricultural sector due to its heavy reliance on rainfed agriculture. At the same time, the availability of rainfall is uncertain due to natural climatic variability which is worsened by climate change. Already the local farmers have knowledge of the climatic conditions around them, and from time to time, they have been adjusting their farming practices in line with the prevailing climatic conditions. Climate...