Assessment of the effect of cement industry effluent discharge on water quality of Ngo River in Benue, Nigeria

Ngo River in Gboko, Benue State, Nigeria which serves as a source of water for domestic and agricultural purposes for the agrarian community receives effluent from Dangote Cement factory. Physicochemical analysis of the effluent outfall and water samples collected along 15 km of the river stretch were carried out in dry and wet seasons respectively. The results obtained were compared to FEPA, WHO and NESREA Standards. For effluent outfall, Temperature, TDS, pH, EC, BOD, COD, sulphate and chloride, total hardness, calcium and magnesium, were found to be within the FEPA standards, while TSS, turbidity, and nitrate, were above the standards. Along 15 km study reach, mean temperature range of 32.4oC to 29.0oC, a TSS of 224 mg/l to 218 mg/l, a turbidity of 45 NTU to 42 NTU, and DO of 1.6 mg/l to 1.2 mg/l were obtain during the dry season, while mean temperature range of 36.8oC to 36.6oC, a TSS of 255 mg/l to 252 mg/l, turbidity of 176 NTU to 168 NTU, and DO 2.8 mg/l to 2. 6 mg/l were obtained during the wet seasons. These results were above WHO and NESREA temperature (25oC drinking water), TSS (30 mg/l domestic and 100 mg/l agriculture) water use, 5 NTU turbidity, and 5mg/l to 7.5mg/l DO standards. The effluent is relatively treated and effects such as aquatic depletion in the environment, decreased soil pore size and decreased permeability in the use of the water for irrigation, and water related diseases are not ruled out. Keywords: Cement industry, Effluent discharge, Water quality, Ngo River

Engine performance of blends of palm kernel oil biodiesel under varying speed at constant torque

This study conducts a comparative evaluation the effect of using palm kernel oil (PKO), pure petroleum diesel and their blends (B5, B10, B20, B30, B40, and B100), on the performance of a four-cylinder CI diesel engine (David Brown 990: 58hp; 2WD), at Farm Power and Machinery Test laboratory Centre (FPMTLC), Department of Agricultural and Bioresources Engineering, University of Nigeria, Nsukka. The objective of the study was to determine the fuel consumption rates, energy expended, brake specific fuel consumption, and brake thermal efficiency, under varying operating speeds (700 – 1900rpm) at constant torque. Each fuel test was conducted using the Heenan-Froude hydraulic dynamometer engine-test-bed; pure petroleum diesel (B0) was used to generate the baseline data. Variables calculated were analyzed, then compared with each other to determine the differences in the engine performance and also to determine the optimum test fuel. The results obtained show that B10 had the overall optimum energy output, fuel consumption rates, and brake specific fuel consumption of 5431.809J, 3.42E-07 m3/s, and 0.16569l/KWh, respectively at the highest engine speed of 1900. B10 had an excellent brake thermal efficiency of 60.6% but was not better than B100, which showed a higher value of 66.95%. From the analysis, B10 is the optimum test fuel and can be used as an alternative fuel in David Brown 990 (58hp; 2WD) or similar CI diesel engines without any engine modification, even though B100 showed potential as an alternative to fossil diesel. Biofuel production grows through integrated aquaculture and algae production; the algae oil will serve as a raw material for biofuel production Keywords: Blends, Biodiesel, Brake Specific Consumption, Diesel Engine, Fuel Consumption rate, Thermal Efficiency

Development and testing of a capacitive digital soil moisture sensor with printed circuit board as a probe

The quantity and quality of water present in the soil determine to a greater extent the performance of agricultural crops. Real-time determination of moisture content has a greater advantage over the traditional gravimetric method of determining soil moisture content. Thus, this work was based on the design and construction of a cost effective digital capacitive soil moisture sensor for real-time measurement. The moisture sensors comprised four integrated units namely: power supply unit with a 9V DC battery as a power source, sensor unit with a locally sourced Printed Circuit Board (PCB) as the single sensing probe, control unit made up of PIC16f877 microcontroller programmed with a C language and the C source code compiled in Corporate Computer Services Compiler (CSS C) compiler development environment, and a 16x2 display unit which displays the readings in percentage moisture content (%MC) and capacitance (μF) of the soil obtained from the sensor on its screen. Standard gravimetric moisture content was carried out to get the calibration factor which was used to calibrate the sensor for reliability. The validation was done by taking the reprogrammed (calibrated) sensor to the field for further measurement, after which soil samples were collected for further gravimetric analysis. A regression equation was obtained by plotting the moisture content obtained from gravimetric method (%MCG) against that from sensor reading (%MCS) with a high degree correlation coefficient (R2) of 0.998. The developed capacitive soil moisture sensor is cheap, portable, reliable and easy to use even by local farmers. Keywords: Calibration, Capacitive sensor, Printed circuit board, Soil moisture content, Validation