Analysis of Physicochemical Parameters of Sewage Water used for Irrigation in Bauchi Metropolis - Nigeria

This study was carried out to investigate the physicochemical parameters of sewage water used to irrigate vegetable farmlands along one of the major drainage channels in Bauchi metropolis - Nigeria. Sewage water was collected from six different sampling sites. Temperature (23 – 25 o C), pH (8.11 – 8.4), electrical conductivity (850 µScm-1 – 1524 µScm-1) hardness (210 mg/L – 298 mg/L), alkalinity (63 mgCaCO3/L – 95.5 mgCaCO3/L), nitrate-nitrogen (4.72 mg/L - 11.44 mg/L) and phosphate-phosphorus (1.00 mg/L - 2.38 mg/L) were determined in sewage water samples in the study areas. In the control sample, Temperature (30.7 o C), pH (7.41), electrical conductivity (320 µScm-1) hardness (125 mg/dm3), alkalinity (54 mgCaCO3/ dm3), nitrate-nitrogen( 3.8 mg/ dm3) and phosphate-phosphorus ( 0.10 mg/ dm3) were determined.. All the physicochemical parameters determined were found to be within FAO/WHO standard limit for irrigation water except for electrical conductivity, hardness and nitrate-nitrogen. The high values of these three parameters obtained from the study areas may indicate that the sewage water samples contain more plant nutrients in it than the control area water sample, where these values were all lower than the permissible limits. It may also indicate a higher pollution level compared to the control area. Keywords: Bauchi metropolis, pollution, physicochemical parameters, sewage water, irrigation.

Evaluation of Intelligent Wells Performance in a Five-Spot Arrangement

The efficiency of water flooding processes can be improved by installing intelligent wells which are good candidates for control and optimization. Optimal control theory based on adjoint formulations was found to be efficient for reservoir optimization. However, this solution approach is local and may not be suitable for comparing design alternatives. In this work, an approach for determining an optimal starting point for optimal control theory procedure was developed to give near global optima. The performance in terms of net present value (NPV) of two forms of five-spot pattern was compared. The method results to similar performances of the two alternatives because it was formulated to give true optimal solution trajectories. It was found that regular five-spot pattern results to a NPV in excess of $4,900 over inverted design. Respective increase in oil and water productions of 0.23% and 0.22% were recorded for former design against the later.Keywords: intelligent wells; adjoint; optimal control theory; global optimum; water flooding

L-Arginine Grafted Chitosan as Corrosion Inhibitor for Mild Steel Protection

Corrosion prevention has been a global phenomenon, particularly in metallic and construction engineering. Most inhibitors are expensive and toxic. Therefore, developing nontoxic and cheap corrosion inhibitors has been a way forward. In this work, L-arginine was successfully grafted on chitosan by the thermal technique using a reflux condenser. This copolymer was characterized by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The corrosion inhibition performance of the composite polymer was tested on mild steel in 0.5M HCl by electrochemical methods. The potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results were consistent. The inhibition efficiency at optimum concentration rose to 91.4%. The quantum chemical calculation parameters show good properties of the material as a corrosion inhibitor. The molecular structure of the inhibitor was subjected to density functional theory (DFT) to understand its theoretical properties, and the results confirmed the inhibition efficiency of the grafted polymer for corrosion prevention