Investigation of Some Gaseous and Trace Metal Emissions With Their Emission Factors From Various Brands of Mosquito Coils Used in Nigeria.

Mosquito coils of various brands are frequently burnt in indoor environments to drive away mosquitoes-the vector for malaria parasite in regions where the disease is endemic. Emissions from the coils could be a source of indoor air pollution. In this study, various brands of mosquito coils obtained from retail shops in Lagos, Nigeria were burnt in an environmental test box with a view to characterizing carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2) in the gaseous emissions as well as elemental concentrations of the ash. Emission characterization achieved with the RAS1700 bio-gas analyzer while AAS was adopted for elemental analysis of the mosquito coil ashes. The emission factor of CO, NO and NO2 from the coil samples ranged between 0.00138 to 0.26277 µg/m3, 0.0002 to 0.00454 µg/m3, and 0.000074 to 0.00714 µg/m3, respectively. These values were found to be lower than permissible indoor levels recommended by NIOSH. The range of concentrations of Pb, Zn, Cd, Cr, Cu, As, Hg, Fe in the coil ashes from all the brands were 0.02 to 0.04 mg/g, 0.011 to 0.02 mg/g, 0.001 to 0.003 mg/g, 0.004 to 0.008 mg/g, 0.004 to 0.006 mg/g, 0.0001 to 0.0004 mg/g, 0.001 to 0.003 mg/g, and 0.124 to 0.14 mg/g, respectively. Although, the concentrations of the pollutants obtained in this study are within the recommended limits, prolong exposure could trigger chronic disease conditions. Adequate ventilation of indoor environments or utilization of mosquito nets in place of coils could be considered.

Production of activated carbon from sawdust and its efficiency in the treatment of sewage water.

When water is contaminated and rendered unfit for drinking, it is regarded as waste, which leads to water pollution. Several works have been done to control water pollution, yet this topic is still a point of concern up to date. The study involves the production of activated carbon (AC) using sawdust to treat sewage water obtained from Covenant University. The following conditions were investigated; activation time and temperature, activating agent concentration, and impregnation time. The AC was characterized by measuring ash content, iodine value, moisture, and volatile matter content. The optimum activated carbon prepared in this study had iodine of 1628.95 mg/gm, while the minimum activated carbon had an iodine of 470.41 mg/gm. According to standard procedure, the sewage water sample was characterized physio-chemically before and after treatment using activated carbon as an adsorbent. The results obtained indicated considerable improvement in the quality of the water. When optimum activated carbon was used for treatment, pH value changed from 7.7 to 7.10, biochemical oxygen demand (BOD) was reduced from 288 mg/l to 20 mg/l and Total dissolved solids (TDS) reduced from 183.7 mg/l to 16.4 mg/l, Total suspended solids (TSS) reduced 232 mg/l to 15.7 mg/l. When minimum activated carbon was used for treatment, pH value changed from 7.7 to 7.60, BOD was reduced from 288 mg/l to 112.2 mg/l, and TDS reduced from 232 mg/l to 174 mg/l, TSS reduced 183.7 mg/l to 103 mg/l. The results obtained led to the conclusion that the produced activated carbon effectively treats the above-stated water quality parameters.

Data on the treatment of used lubricating oil from two different sources using solvent extraction and adsorption.

The data in this article were obtained from a research designed to investigate the effects of choice of solvent, mixing speed, temperature and solvent to oil ratio on the treatment process of used lubricating oils using solvent extraction and adsorption method. Various data on the performance of the three solvents chosen were studied and compared based on certain parameters are presented and discussed. From the results obtained, it was observed that MEK (Methyl Ethyl Ketone) had the best performance because it gave the highest sludge removal and closest properties to the fresh lubricating base stock. Furthermore, it was also determined that increase in temperature improved the quality of oil obtained up till 50 °C above this temperature poorer quality of oil was observed. But above all the factors investigated, it was concluded that solvent to oil ratio has a greater effect on the quality of oil produced after treatment.