No abstract

Slaughterhouse wastewater in Nigeria poses a risk to public health due to lack of treatment as the conventional treatment plants have proven non-sustainable. Constructed wetlands (CW) have emerged as an efficient technology for treatment of wastewater in developing countries because of its low cost, ease of operation/maintenance and good performance. The feasibility of using CW to remove pollutants from slaughterhouse wastewater was tested using three macrophytes; Thalia geniculata, Colocasia esculenta and Typha latifolia. The result showed that all macrophytes tolerated of the tested conditions. The BOD, TSS, NH 3 -N, NO 3 -N and PO 4 3of slaughterhouse effluent reduced after treatment in all cells. There was a higher removal of most pollutants in planted than in unplanted cells. The Thalia geniculata cell outperformed the others for TSS and Original Research Article

Excessive sediment deposition results to hydro-ecological problems particularly for shallow streams that experience significant point-source pollution. In recent times, models have been employed to investigate sediment transport in river systems. The aim of this research work is to model sediment transport of Ele River using particle tracing methodology. The governing equations of fluid flow and particle movement were modelled using COMSOL Multiphysics 5.3a. The result was validated using experimental data and the model result showed good agreement with coefficient of determination of 0.99. Study results showed that sediment at the river banks posses lower velocities compared to sediments in midstream. This implies higher sediment deposition at the banks due to low flow velocity. These sediments deposition constitute problems to the river system through degradation of water quality and blocking irrigation nozzles, impacting irrigation efficiency and crop production.

Wastewater treatment using constructed wetlands is one of the effective and low-cost technologies to improve the quality of slaughterhouse effluent. This study was carried out to investigate the suitability of palm kernel shell as a substrate material for constructed wetlands treating slaughterhouse wastewater. Rhizomes of Thalia Geniculata and Typha Latifolia were grown in four pilot horizontal subsurface flow constructed wetland beds filled with palm kernel shell and grave, and their growth and treatment performance evaluated. The results of the study showed that Thalia Geniculata survives and proliferates in palm kernel shell bed. The mean removal rates of 72.81% (BOD5), 89.87% (TSS), 39.42% (NH4-N), 60.79% (NO3-N) and 42.52% (PO43-) for the palm kernel shell were comparable to the values obtained for the gravel bed. The study proved that palm kernel shell, as a substrate material in constructed wetlands had the potentials to sustain the growth of some macrophytes, as well as the capacity to remove contaminants from wastewater.

Extreme climatic factors (temperature, precipitation etc) which at times lead to drought and flooding affect crop yield negatively. In this study, a PVC drip irrigation was developed and the irrigation parameters were evaluated in a farmland with three tillage methods (conventional tillage, conservative tillage and no tillage). The irrigation treatments comprised of three levels of irrigation (50% Management allowable depletion, 30% management allowable depletion and 10% management allowable depletion). Different irrigation parameters were evaluated for different crop growth stages, different soil treatments and different soil depths (0-25 cm, 25-50, 50-75 and 75-100 cm depths). The field capacity was determined at -0.01MPa, from the result, the field capacity was minimum at no tillage (0.07 cm3/cm3, 0.11 cm3/cm3, 0.12 cm3/cm3, and 0.14 cm3/cm3) for soil depths 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm respectively, for conservative tillage (0.11 cm3/cm3, 0.11 cm3/cm3, 0.11 cm3/cm3, 0.14 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively and conventional tillage (0.09 cm3/cm3, 0.13 cm3/cm3, 0.15 cm3/cm3, 0.17 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively. The permanent wilting point was determined at -1.5MPa, from the result, permanent wilting point increased with increase in soil depth in conventional tillage and no tillage with PWP of 0.01 cm3/cm3, 0.05 cm3/cm3, 0.09 cm3/cm3 and 0.11 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for conventional tillage and PWP of 0.02 cm3/cm3, 0.05 cm3cm3, 0.05 cm3/cm3 and 0.08 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for no tillage. The average net irrigation was found to be 1.2 cm, 1.56 cm and 1.95 cm for conventional tillage, conservative tillage and no tillage respectively, while the average gross irrigation was found to be 1.7 cm, 1.7 cm and 2.1 cm for conventional tillage, conservative tillage and no tillage respectively. Statistical analysis of net and gross irrigation gave a coefficient of determination of 0.99 and p-value at 0.05 was significant with a value of 0.00007.