Advanced Materials Research Vol. 367

Abstract: Research has largely been driven by the quest for innovation, new knowledge and improving the general wellbeing of the human race. Monumental challenges that plague humanity tend to, from time to time, shape research and take it to new heights, and one of such is the global water crisis [1,2]. To restate the obvious that water is the basis of life and the engine for social and economic growth, water resource engineering research attempts to address challenges related to: (i) how water of sufficient quantity and quality can be made available to meet various competing sectoral demands; (ii) how development and exploitation of the resource can be carried out in a sustainable manner so that its benefits extend to future generations; (iii) what adaptation and mitigating measures can be put in place to minimize the impacts of global climate change. This paper, therefore, presents trends in four areas of research in water resources engineering that focus on the paradigm shifts in water supply and sanitation, integrated modeling in order to give quantitative expression to integrated water resources management (IWRM), thereby achieving a more defined space for decision making, new and emerging cost-effective water treatment technologies, and research developments in adaptation measures to climate change.

Abstract: Geophysical survey based on electrical resistivity method employing the techniques of vertical electrical sounding (VES) was carried out in order to investigate Groundwater existence in Delta North District, of Nigeria. This research work became necessary in order to solve the problem of acute water shortage in the area by way of prospecting or searching for additional aquifers which would subsidize the existing one, domestically, industrially and agriculturally. Ten (10) vertical electrical sounding (VES) (uniformly distributed) tests were conducted in the area and its environs using “Schlumberger” electrode array. The VES were carried out with half current electrode spacing with the spread Im-928m at six (06) points per decade. The results of the interpretation identified wet sand/clean sand as perched aquifer which can deliver ground water to the bore-hole at perceptible rates between depths of 85m to 145m below sea level. The resistivity of the aquifer detected varied from 95.0 ohm-m to 110,000 ohm-m while the thickness ranged from 30.0m to 105.0m.

Abstract: Environmental radiation measurement was carried out in several automobile mechanic workshops within Ugbowo area of Benin-City, Edo State, Nigeria. A Digilert 50 Nuclear Radiation monitor was used to ascertain the level of radiation to which these workers are daily exposed. The study revealed that the average annual effective dose rate from these sites is approximately 0.40 mSv/yr which is lower than the value of 1.0 mSv/yr averaged over five consecutive years according to the dose limit placed by the Basic Safety Standards (BSS) SCHEDULE II and the International Commission on Radiological Protection (ICRP) REPORT 60. However, the external background ionizing radiation exposure within the sites investigated varied between 0.1272 and 0.01411 mR/hr with an average of 0.01314 ± 0.000658 mR/hr in the locality which is relatively higher than the standard background radiation of 0.011 mR/hr recommended by the US Nuclear Radiation Commission. This level of background radiation seems to suggest that there is a possibility of the existence of radio nuclides within the area.

Abstract: In most developing countries, solid waste components are generally commingled. Sorting of solid waste is one of the most important activities in the material recovering process of the integrated solid waste management system. If solid waste is sorted, about 30% of the work is done. Several methods exist for sorting comingled solid waste. The work presented in this paper involved the study of solid waste source sorting alternatives in Nigerian Universities. A site-specific study was carried out to characterize the solid waste generated in the University of Benin. Alternative concepts for sorting of solid waste were considered and evaluated. Source sorting was then selected for this study. The study revealed that about 14.56% of biodegradables, 42.26% of plastics, 39.62% of paper waste and 3.56% of metal waste are generated in the office and classroom areas of University of Benin. The study also showed that there is poor attitude to solid waste issues as the maximum cooperation realized on source sorting of solid waste was only about 50% for the waste-bin designated for plastic. The results obtained from the study also indicated that intensive sensitization of the generators on the benefits of source sorting is required for effective source sorting.

Abstract: The equations of Erosion 2D Model (a physically based model) were transformed into a computer programme called EROSOFT and used to predict the rate of soil loss in Makurdi metropolis. The model has detachment, transport and deposition components. Four sites were chosen within the metropolis for this study. Soil samples were collected from the sites for laboratory analysis. Rainfall and runoff fluids were collected from the sites to determine their densities. Levelling instrument was used to detremine the channels slopes. The model predicted an average annual soil loss rate of 310kg m^-2s^-1 for the metropolis. The sensitivity analysis of the model indicates that straight slopes are more prone to soil erosion. The result of the model deviates slightly from established facts that, sandy soils are more erodible and hence prone to be easily detached. Nevertheless, the model shows that soil erosion is influenced by slope geometry and rainfall intensity. The study attributes the major causes of soil erosion in the city to urban runoff concentration and removal of vegetation, and therefore suggests the use of land grading, land forming and cover cropping as well as conservation structures like road side drains for the control of erosion in the metropolis.

Abstract: Pilot scale “Waste Stabilization pond” was evaluated for treating high quality waste water using aerobic process. The method involved the measure of the molecular oxygen utilized during a specified incubation period for the biochemical degradation of organic matter and oxygen used to oxidize inorganic material. Operation of the pond involved engineering construction to reduce the risk of soil and groundwater contamination. Calibration of the model using laboratory tests showed BOD for 5, 10 and 15 days as 101.9mg/l. 273.3mg/l and 426mg/l respectively. Pond efficiency was 76.19%. The design experience and post design results provided knowledge about the efficiency of a waste stabilization pond and the basis of recommendation and practice in developed cities.

Abstract: This study compares the response of Amaranthus candatus vegetable to root-to-shoot signals of soil drying and assesses applicability of the use of partial root zone drying (PRD) technique in increasing water-use efficiency. From a completely block randomized design, seeds were grown on three plots with each having three replicates. Three treatments were compared: half of the root system watered and half droughted by delivering 50% less crop water requirement (CWR) per irrigation depicted as 50%PRD; both halves of the root system received water application of 50% less crop water requirement per irrigation (50%CWR); while in the control treatment, both halves received 100% crop water requirement (100%CWR). The wetted and dried sides of the root system of 50%PRD were alternated on a 7-day cycle throughout experimental period. Effects of the differences in water-use on growth parameters, such as plant height, stem girth; number of leaves and leaf area were examined. Weights at harvest and root-to-shoot ratios were also compared. Drying half of the root system caused marked declines in all growth parameters in 50%CWR but only slight declines in 50%PRD. Since the main effect of water stress on Amaranthus is yield reduction, achieving better yields requires an optimum water supply from planting until ripening. Average edible wet weights (yields) of the 50%PRD and 50%CWR water applications when compared with the control were 81% and 25% respectively. The higher yield in 50%PRD may be attributed to high stomata sensitivity to drought signaling, as indicated by relatively low root to shoot ratio of 0.33. This lower ratio for 50%PRD treatment, compared to 50%CWR and 100%CWR with 0.40 and 0.66 values, was an indication of healthier and more profitable plants in 50%PRD because the decrease came from a greater shoot size.

Abstract: Mixed layer depth, Solar and flare stack radiations, Atmospheric boundary layer Abstract: Mixing of chemical species released from pollution sources occurs at certain heights in the atmospheric boundary layer of the troposphere. Within this height, mixing of materials occurs due to convective heat transport and mechanical (wind) actions. The mixed layer height can be estimated by analyzing measured meteorological parameters. In this study, the parameterization of meteorological variables based on established mathematical models were used to compute mixed layer height over Olorunsogo in Ogun State, Nigeria. The vertical extent through which pollutants mix occurs was described in a height-temperature profile for both the day time and nocturnal characteristics. The mixing depths were computed for two locations comprising one area with gas flaring operation present and another with no flare stack present. The findings of this study revealed that mixed layer depth for the location without flaring activities, day time ranged between 1200m and 1400m, and at night time as well as early morning ranged between 150m and 400m. In contrast with the location where gas flaring occurred, mixing height ranged between 9280m and 9310m for day time and between 9100m and 9180m for nocturnal period. In addition, it was observed that pollution trapped below the flare during the day, experience rapid vertical motion due to outgoing long wave radiation (OLR) from the surface. While above the flare a vertical motion coupled with dispersion occurs under lapse rate for pollutants, but remained trapped at the inversion layer. At night time, pollutants around the flare advect vertically and experience rapid vertical dispersed motion and after going through the flare are trapped at the inversion layer. Hence most submicron sized particulate matter hardly reaches ground level over areas where gas flaring operations occur except entrainments in wet depositions predominantly through rainfall.

Abstract: The rate of transformation of ozone in the troposphere over a temperature range of-100°C and +100°C has been established. Tropospheric ozone with the quality of a strong oxidizing agent, is secondary pollutant species associated with the initiation of numerous chemical reactions in the atmosphere. In this study, a theoretical approach utilized Gibb’s free energy of reaction and enthalpy of reaction in transition state theory model equations to generate chemical equilibrium data and consequently reaction kinetic parameters. The thermochemical properties were obtained using electronic structural methods of the quantum mechanics computational chemistries which approximates the Schrödinger equation. The model chemistry methods were evaluated using the GuassView for generating molecular structures of species and the Gaussian 03 (G03) package for energy computation. The study revealed that the most relevant of the reactions considered was that involving NO with a rate constant of 7.39 x 10¹¹ s^-1 and energy of activation (E_A/R) of-216.98 K while the least involved HS* with rate constant of 9.56 x 10⁶⁹ s^-1 and energy of activation (E_A/R) of-202.95 K.