The fate of end-of-life electronics (e-wastes) is of increasing concern because of their toxicity and ever increasing volumes. Addressing these concerns requires proper management plans and strategy which in turn requires reliable estimates of e-waste generation in the present as well as future times. In this study, a material flow model for the analysis of e-waste generation from computer equipments in Nigeria has been developed. Data used to develop the model are the sales data from major distributors of electronics, usage time of computer equipments and transfer coefficients of the electronics from one stage to another. The analysis of individual flows of computer from the material flow model showed that the fate of obsolete computer equipments were storage (41%), reuse (35%) and direct disposal (24%). The projections of the flows for a period of 15 years also indicated that storage and reuse of computer equipments would be preferred over direct disposal; and computer equipments would continue to remain in either storage, re-use or gradually disposed off for about 11 years after its inflow. This delay or staggering disposal is of advantage as it would reduce the amount of e-waste disposed yearly and also afford the country some time to make plans to accommodate and manage the e-wastes generated more efficiently.

The activities involved in the production and exploration of crude oil has constantly polluted the environment. This study investigated the ability of an indigenous fungus to utilize petroleum hydrocarbon. Response Surface Methodology was used to optimize the effects of pH, microbial concentration (spores/ml), and contact time (days) on the crude oil removal efficiency in refinery effluent. Monocillium sp. was isolated and used for the treatment of refinery effluent due to its predominance in the contaminated soil. Twenty experimental runs were analyzed to determine the effect of pH, microbial concentration and contact time on the oil removal efficiency. From theexperimental results obtained, a maximum oil removal efficiency of 98.42 % was achieved at a pH of 6.5, contact time of 14 days, and a microbial concentration of 3 spores/ml. The results obtained showed the percentage of crude oil removal in the effluent sample  increased with an increase in time. Optimization of the experimental result was achieved at a removal efficiency of 98.59 %, a contact time of 13.96 days, a pH of 6.85, and a microbial concentration of 3.01 spores/ml. The findings of this study revealed that Monocillium sp. is a viable hydrocarbon degrader, and can be used in the bioremediation of petroleum contaminated environments. Keywords: Response surface, optimization, bioremediation, hydrocarbon, removal efficiency, Monocillium sp.

Objective: In recent years, vended water has increasingly become a source of drinking water in most of the urban and rural centers of developing countries due to inadequate piped water supplies. Hence, this study assessed the quality of vended water and its level of contamination at source, during transportation, and at point of use in Unguwar Liman area of Samaru-Zaria during rainy and dry seasons. Materials and Methods: This included assessment of physicochemical and bacteriological characteristics and comparing the findings with the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ). The water samples were analyzed for color, turbidity, total dissolved solids (TDS), pH, nitrate, phosphate, biological oxygen demand (BOD), and total coliform (TC). Results: The color of all the samples was constant at 5 true color unit irrespective of season and point of sampling. However, the mean concentrations or values of the three points assessed for turbidity, TDS, pH, and nitrate during dry and wet seasons were 1.693 and 2.663 nephelometric turbidity unit; 670 and 257 mg/l; 8.3 and 7.3 then 0.105 and 0.178 mg/l, respectively. Similarly, the mean concentrations for phosphate, BOD, and TC during dry and wet seasons were 0.0006 and 0.0068 mg/l; 1.052 and 0.928 mg/l, and 4 and 27 most probable number/100 ml, respectively. The result also revealed that all the physicochemical parameters investigated were within the acceptable limits of the WHO standard and NSDWQ irrespective of the season (except TDS during the wet season), while coliform counts were above the permissible limit during both seasons. Conclusion: It was established that the vended water of the study area has better quality during the dry season hence, inhabitants of the study area were advised to disinfect vended water mostly during the rainy season before consumption in other to avoid waterborne diseases.

Fungi dwelling in soils contaminated by petroleum products can survive on these hydrocarbons due to the highly effective extracellular enzymes. Species belonging to the genus, Aspergillus are known to be efficient degraders of various classes of hydrocarbons as well as other organic contaminants. In this study, the biodegradation of crude oil by Aspergillus niger and Monocillium sp. were compared using laboratory microcosms.The moulds were isolated from a site receiving effluent from a petroleum refinery. They were identified using their macroscopic and microscopic characteristics and subsequently screened for their ability to utilize hydrocarbons for their metabolic requirements. Following the biodegradation studies, Aspergillus niger and Monocillium sp. recorded an increase in hydrocarbon utilizing fungal counts of 8.5 x 107 spores/ml and 6.1 x 107 spores/ml and crude oil weight loss of 80 % and 70 %. Both fungi were tested singly and in a consortium for their ability to degrade crude oil, itwas observed that Monocillium sp. and A.niger performed better when tested individually (94.2 %; 92.8 %) than in consortium (76.3 %). This may suggest that their combined metabolism may have created some antagonistic effect on the degradation process as opposed to their enzymatic capabilities which appeared to be more favourable to the process. The biodegradation experiment analysis showed that contact time plays a  significant role in biodegradation of crude oil (p<0.05), and Monocillium sp. and Aspergillus niger are excellent crude oil degraders and can be usedin the bioremediation of petroleum-contaminated soil and water. Keywords: Biodegradation, Aspergillus niger, Monocillium sp., soil, Crude oil

The production of activated carbon from agricultural waste is one of the mostenvironmental friendly solutions of transforming less valuable into more valuable materials and it is also a way of converting waste to wealth. Rice husks, maize cobs and coconut shells were individually used to prepare activated carbon under the same experimental conditions of 500OC carbonization temperature, impregnation ratio of 10:1 under 1hr activation time using chemical activation method with zncl2 as the activation agent. After being subjected to carbonization and chemical activation, the farm residues were examined for their surface areas, PHs, conductivities, specific gravities, bulk densities and moisture contents. Elemental composition of each of the waste at carbonized stage, when chemically activated, when used to trap air pollutants and when reactivated were also determined. The adsorptive capacities of these activated carbons were investigated and compared by loading each of them in an adsorption column of 1.5m tall, 0.98m diameter with four openings at height 0m (input), 0.5m, 1.0m, 1.5m (output). A 0.85kva generator was connected to the column and the concentrations of some selected primary pollutants (HC, CO, CO2 NOX) were determined at the input was analyzed and compared to the concentrations at different heights in the column, as the fumes passed through. Optimization studies were also carried out to investigate the adsorptive efficacies of blends of the activated carbons, at different ratios and proportions. When the three activated carbons were mixed at same ratio and proportion, the adsorptive capacity was found to be less than when compared to the efficiencies of the individual activated carbons. Activated carbon produced from coconut shells was experimentally found to have the highest adsorptive capacity followed by that produced from maize cobs and rice husks. The adsorptive capacity was experimentally found to be dependent on adsorbate dosage, contact time and concentration of the adsorbate. CO and CO2 were found to be easily absorbed by all the three activated carbons. Some recommendations have been made.