Pollution

The study considered the transport of a radioactive solute in solution from the ground surface down through the soil to the groundwater when there is an accidental or intentional spillage of a radioactive material on the surface. The finite difference method was used to model the spatial and temporal profile of moisture content in a soil column using the ?-based Richard’s equation leading to solution of the convective-dispersive equation for non-adsorbing solutes numerically. A matlab code has been generated to predict the transport of the radioactive contaminant, spilled on the surface of a vertically heterogeneous soil made up of two layers to determine the residence time of the solute in the unsaturated zone, the time it takes the contaminant to reach the groundwater and the amount of the solute entering the groundwater in various times and the levels of pollution in those times. The model predicted that, when there is a spillage of tritium, on the surface of the ground at the study area, it will take two years for the radionuclide to enter the groundwater and fifteen years to totally leave the unsaturated zone. Therefore, it is very important that proper containment measurements be put in place to take care of such spillages since they have long term effect.

Erosion and sediment yield are important factors that should be taken into account in planning renewable natural resource projects. The EPM model is extensively used to erosion and sediment yield assessments in many catchments of Iran. Because of ambiguities in the validity of the results of EPM model, the objective of this study is to evaluate the output results of this model in five small catchments, Semnan Province, Iran using sediment deposited in reservoir constructed in the outlet of these catchments. The Specific Sediment Yield (SSY) in five reservoirs was assessed by measuring the volume and mass of deposited sediment in the reservoirs and also by characterizing the reservoirs and their respective catchments. The primary data for EPM model was obtained from topographic maps, aerial photographic interpretation, earlier studies and field survey by a team with different professional backgrounds in order to score each model’s factors. Model performance was evaluated by using Nash and Sutcliff’s Model Efficiency (ME) and the Relative Root Mean Square Error (RRMSE). Result showed that although the amount of Model Efficiency is located in acceptable area (0.056) but no high efficiency. The Relative Root Mean Square Error (79.3) show the efficiency of model is low as well.

A characterization and volumetric analysis of Olomoro field was carried out using data provided by Shell Petroleum Development Corporation in order to determine the reservoir lithology, structure properties and hydrocarbon in-place. The data provided were well logs, structural map and the seismic section of Olomoro field. The well logs utilized included gamma ray, resistivity, caliper, density, neutron and sonic logs. Through the gamma ray log, it was discovered that the interval under investigation had four porous and permeable zones or reservoir interval. The resistivity log revealed with exception of the first to the third reservoir layer of well 1, presence of hydrocarbon which was used to calculate resistivity of the formation and water. The water saturation was calculated which in turn was used to calculate the hydrocarbon saturation. The values derived were used to estimate the hydrocarbon in place within the depth of 3,429m and 4,053.84m for an area of 100km². These gave a total of 4.012 x 10⁹m³ or 2.5234 x 10¹⁰ barrel as the hydrocarbon in-place. It was observed through the structural map and the seismic section that the hydrocarbon trap is a structural trap created by two fault plains and a folded anticline.

The main chemical used for the gold mining is Mercury. It is widely considered to be among the highest priority environmental pollutants of great concern to the world. Concerns about mercury are based on its effect both on ecosystems and human health. Mercury levels in various foodstuffs were determined by instrumental neutron activation analysis (INAA). High level of Hg was found in all the foodstuffs collected from mining areas. Generally, Hg concentration in foodstuffs ranged from Capsicum sp <0.01 to 69 µg/kg > Xanthosoma sagittifolium <0.01 to 67µg/kg, Nbelmoschus esculentus <0.01 to 67 µg/kg > Colocasia esculentus <0.01 to 66 µg/kg > Manihot esculentus <0.01 to 65 µg/kg , Musa paradisiacal <0.01 to 65 µg/kg , leaves of Xanthosoma sagittifolium, <0.01 to 65 µg/kg > Solanum melongena <0.01 to 63 µg/kg, > Lycopersicum esculentus <0.01 to 54 µg/kg. Most of the values far exceed the WHO recommended values of Hg in foodstuffs, 20ngHg per gram fresh weight. This is not surprising because of the large amount of mercury the illegal miners add in order to be sure that they have all amalgamated available gold. Hg levels should be carefully monitored in the Wassa west district in Ghana.

This present investigation aimed at assessing the water quality of the Densu delta. Data on some ions namely Na⁺, HCO₃^-, Cl^-, K⁺, SO₄^2-, NO₃^--N and PO₄^3--P were measured. The pH, temperature, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen, biochemical oxygen demand were also determined to assess the chemical status and pollution levels of the river. The ranges for BOD (3.40-4. 21), Na⁺ (104-29800), Cl^-(67.98-19194 ), K⁺ (16.90-4630),PO₄-P(0.0063-0.032 ), NO₃-N(0.19 - 0.60 ) and SO₄^2-(224.67-23700) were found to be higher than the natural background levels for surface water. This indicates pollution of the river water samples from the areas studied. Our findings highlighted the deterioration of water quality of the river due to anthropogenic activities.

Relationship of landscape position and soil properties to maize (Zea mays L.) yield was studied in coastal plain soils of Akwa Ibom state. The study aimed at assessing the physico-chemical soil attributes down the geomorphic surface as well as assessing the yield of maize in the respective landscape positions. A total of 3600 plant population (hybrid maize) were planted on 0.072ha in a Randomized complete block design. The traditional land preparation technique was employed after slashing the re-growth vegetation with cutlass. The trashes was left on the sites and allowed to dry for three weeks before burning. Pre-burn soil samples were taken before burning the trashes at the end of three weeks after slashing. The samples collected were analyzed in the laboratory for physico-chemical properties using standard methods (ASTM and IITA). Collected data were statistically analyzed and means of statistically significant parameters were separated using LSD (0.05). The results showed that sand particle of burnt and un-burnt soils were significantly different at 0-15cm of Upper slope (US) but not significantly different in other landscape positions (p<0.05). Soil pH in burnt soil was significantly different from the un-burnt soil (both at surface and sub surface) in the three landscape positions. Mean maize yields (with husk) was 0.09 and 0.11kg/ha ‘before’ and ‘after’ burning plots of US ; 0.12 and 0.16kg/ha in ‘before’ and ‘after’ burning plot of the middle Slope (MS) while the Bottom valley (BV) had 0.14 and 0.16kg/ha in ‘before’ and ‘after’ burning plots. Altogether, both husked and de-husked yields were higher in burnt plots than un-burnt plots. Along the slope, husked yield followed the order: BV (0.15kg/ha) > MS (0.14kg/ha) > UP (0.10kg/ha)) while de-husked yield also followed similar pattern but different magnitude.

The feasibility of activated carbon prepared from Jatropha Curcas stem waste to remove Reactive Blue 2 from aqueous solution was investigated through batch mode contact process. The effect of various experimental parameters, such as initial dye concentration (20mgl/L), pH 6.5, adsorbent dosage 50mg and Temperature 30 °C was investigated in a batch mode-adsorption technique, the optimum condition for removal of Reactive Blue 2 Dye was found to be pH 6.5. The equilibrium data were best represented by the Langmuir isotherm model, with maximum mono layer adsorption capacity. The kinetic data were fitted to pseudo first order, pseudo second order and intra particle diffusion models and it was found to follow closely the pseudo second order kinetic model.

Waste management process involves the collection, transportation, processing or disposal, managing and monitoring of waste materials. waste management relates to materials produced by human activity and the process is generally undertaken to reduce their upshot to the environment and the human health. Waste management is a distinct performance from recovery which focuses on delaying the rate of consumption of natural resources. Recycling involves the gathering and reuse of waste materials, The materials from which the items are made can be reprocessed into new products. Recycling may be collected separately from general waste using dedicated bins and collection vehicles, or sorted directly from mixed waste streams. Solid wastes are a by-product of a broad spectrum of industrial, service and manufacturing processes. Primary products used by households that can be recycled include the metals, wood, paper, leather, textile among many also recoverable materials that are organic in nature, such as plant material, food scraps, and paper products, can be recovered through composting and digestion processes to decompose the organic matter. The resulting organic material is then recycled as mulch or compost as for agricultural or landscaping purposes. This study will explore boulevards which are used by resident of Kisii town to be able to recycle their refuse and sustain proper environmental conditions which in turn reduce the diseases associated with the environment.

The study reports the adsorption of safranin onto NaOH-modified rice husk in a upward packed bed column. Effects of the operating parameter such as flow rate, influent dye concentration were studied. To determine the characteristic parameters of the column, four models- Thomas, Adams–Bohart, BDST, and Yoon–Nelson models were applied to the experimental data. The results showed that Thomas model best fitted with the experimental data at various flow rates, while Yoon-Nelson model was suitable with data at various safranin concentrations. Moreover, it was observed that on increasing the concentration of safranin, adsorption capacity increased which in turn decreased on increasing the flow rate. Least sum of square (SS) and ?2 error analysis were applied to the models to find out the best fit model with the experimental data. An artificial neural network (ANN) model was developed to predict the decolorization of the dye solution in upward packed bed column. The model provided reasonable predictive performance (R2 = 0.988).

Twenty samples of domestic water sourced from different underground wells in Gidan Dare and Gidan Igwai areas of Sokoto were collected and analyzed in the laboratory. The pH and the electrical conductivities (EC) of the water samples were also determined. The mean results obtained from the analyses were pH (7.68, 6.72) and electrical conductivities (1061µs/cm, 1057µs/cm) for Gidan Dare and Gidan Igwai, respectively. The results also showed mean arsenic concentrations of 0.110mg/L and 0.217mg/L for Gidan Dare and Gidan Igwai water samples respectively, which are above the World Health Organization (WHO) drinking water guideline. Wells in Gidan Dare and Gidan Igwai were found to be contaminated with abnormal concentration of arsenic, high enough to cause serious adverse health effects to its consumers. The high arsenic concentrations could be attributed to both natural and anthropogenic activities such as erosion, underground weathering, toxic chemicals, improper waste and sewage disposal waste from industries, agricultural activities and vehicular emissions.