Assessment of groundwater contamination by leachate near a municipal solid waste landfill

Physico-chemical and microbiological parameters were analyzed in leachate and groundwater samples obtained at different locations adjacent to a municipal solid waste landfill in order to assess the impact of leachate percolation on groundwater quality. Total dissolved solids (TDS), electrical conductivity (EC), and Na+ exceeded the World Health Organization (WHO) tolerance levels for drinking water in 62.5, 100, and 37.5% of the groundwater samples, respectively with pH and Fe exceeding WHO limits in 75% of the samples. Significant negative correlations of -0.839, -0.590, and -0.590 were shown by Na+, TDS, and EC respectively to distance from landfill. A high population of Enterobacteriaceae ranging from 4.0 × 103 ± 0 to 1.0575 × 106 ± 162,705 CFU/ml was also detected in the groundwater samples, indicating contamination. The results show that the leachate from the landfill has a minimal impact on the groundwater resource and this can be attributed to the existing soil stratigraphy at the site consisting of clay which is deduced to have a significant influence on the natural attenuation of leachate into groundwater.Keywords: Groundwater, correlation, percolation, landfill, leachate, municipal solid waste, natural attenuation, Enterobacteriaceae

Variable Weighted Multi-Objective Multi-Dimensional Genetic Algorithm for Demand Response Scheduling in a Smart Grid

This research presents the optimized scheduling of demand response loads of a residential community of 30 houses using a multi-objective multi-dimensional genetic algorithm (MOMD-GA) with a variable weighted objective function. Incorporating day ahead hourly real time pricing (RTP), the MOMD-GA attempts to present possible optimized dispatch patterns with their associated penalties and constraints (environmental, consumers and suppliers) thus providing system operators (SOs) and distribution network operators (DNOs) sufficient data for real time decision making. The variable weights for each considered component of the cost function is chosen to force the MOMD-GA towards exploring optimum solutions with lower environmental cost. Further shown are the trade-offs in selecting particular dispatch bias (consumer, supplier, environmental and optimized) and the impact of the various dispatch scenarios on the cost of overall electricity bill of the community

An Estimate of the Incidence of Prostate Cancer in Africa: A Systematic Review and Meta-Analysis

Prostate cancer (PCa) is rated the second most common cancer and sixth leading cause of cancer deaths among men globally. Reports show that African men suffer disproportionately from PCa compared to men from other parts of the world. It is still quite difficult to accurately describe the burden of PCa in Africa due to poor cancer registration systems.We systematically reviewed the literature on prostate cancer in Africa and provided a continentwide incidence rate of PCa based on available data in the regio

Comparative Catalytic Properties of Ni(OH)2 and NiO Nanoparticles Towards the Degradation of Nitrite (NO2 - ) and Nitric Oxide (NO)

Nitrite (NO2 - ) and nitric oxide (NO) have been identified as an environmentally hazardous analytes from discharged industrial effluents. Thus in this study, nickel oxide (NiO) and nickel hydroxide (Ni(OH)2) nanoparticles were synthesized using the complexation-precipitation method and their catalytic properties towards NO2 - and NO investigated. The success of the synthesised nanoparticles was confirmed using characterisation techniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and the Fourier transformed infrared (FTIR) spectroscopy. The sizes of the synthesized NiO and Ni(OH)2 nanoparticles were estimated to be 5.39 and 5.07 nm respectively. The catalytic behaviour of NiO and Ni(OH)2 nanoparticles towards the oxidative degradation of NO and NO2 - in acidic and neutral media respectively was studied using UV-Vis spectrophotometer. Result indicated that NiO nanoparticles demonstrated better catalytic properties at different reaction time towards NO2 - and NO oxidation compared to Ni(OH)2, while NiO and Ni(OH)2 at nano scale showed enhanced catalysis towards the analytes compared with the bulk Ni salt. The bulk Ni salt did not show any sensing properties towards NO2 - . However in NO, the absorbance intensity due to the generation of nitrate (NO2 - ) was five times higher in the presence of NiO nanoparticles compared with the bulk Ni salt. The improved catalysis of Ni(OH)2 and NiO nanoparticles in this study was attributed to effective pore sizes and large surface area which expose the analytes to more catalytic site. The nanoparticles are simple to prepare, therefore can be used for the fabrication of a simple, portable, miniaturized nitrite and nitric oxide nanosensor for potential clinical and analytical application

Assessment of polybrominated diphenyl ethers in sediment of Asunle stream of the Obafemi Awolowo University, Ile-Ife, Nigeria

Assessment of levels of polybrominated diphenyl ethers (PBDEs) from the sediment of Asunle stream, an adjourning stream of the Obafemi Awolowo University dumpsite, has been carried out. Sediment samples were collected from the stream at six locations for a period of 8 months, composed of 4 months each of wet (May–Aug) and dry (Nov–Feb) seasons. Soxhlet extraction was employed for the isolation of all the target compounds from the sediment samples. Extracts were further subjected to multi-layer column chromatography employing different forms of silica gel. The prepared samples were analyzed using GC-MS. The overall mean concentrations of the total PBDEs ranged from 1.80 to 9.46 ng/g. The results showed that the concentrations of the PBDEs were slightly higher during the wet season than those during the dry season. In all the studied locations, BDE28, BDE47, BDE99, BDE100, BDE153, and BDE154 were detected in all the sediment samples at concentrations that ranged from 0.73 to 10.43 ng/g. Results of this study indicated that BDE153 was the major pollutant of the Asunle stream sediments

Cassava root meal as substitute for maize in layers ration

The effect of replacing maize with graded levels of cassava root meal (CRM) as energy source in the diet of laying hens was evaluated during the eight weeks of feeding experiment on performance and cost benefits on layers. Forty-five Nera black laying hens of 24 weeks of age were allocated to five dietary treatments, with nine birds per treatment in a completely randomized design. CRM was used to formulate the diets at 0, 25, 50, 75, and 100%. The result showed that the feed intake of birds in the control group was significantly (p<0.05) different from those fed the CRM diets. The average weight gain of layers receiving up to 50% CRM was similar to the control birds, but significantly different from layers fed 75 and 100% CRM. No mortality was recorded. Egg production per hen per day and average egg weight were significantly different (p<0.05) for birds consuming more than 50% CRM in T4 and T5. Layer feed ration was made cheaper by the replacement of maize with cassava root meal in the diets