No abstract

The performance and economic viability of a simple inexpensive grey water treatment system consisting of a filtration unit and an adsorption unit was evaluated. At steady state, the overall performance of the combined system was 85.68% BOD removal, 57.09% COD removal and 70.74% TSS removal. Most of the BOD removal (83.6%) was achieved in the filtration unit, while most of the fecal coliform removal was achieved in the adsorption chamber. The pH of the entire system remained stable (7.6 ± 0.29) throughout the experiment. The dissolved oxygen concentration of the final effluent was 1.3 ± 0.28, indicating the need for aeration. Problems with carbon particle washout were observed in the adsorption chamber. Generally, the final effluent was found to be suitable for a range of uses such as toilet flushing, irrigation and fire protection. An economic analysis showed that 77.5% savings in water expenditure can be achieved if a simple greywater treatment is installed for toilet flushing.

The research was aimed at studying the effectiveness of duckweed as a coagulant/disinfectant in the treatment of water and wastewater. Water sample was obtained from River Benue and duckweed was harvested near a residential area in Makurdi Town, Nigeria. Laboratory experiments were carried out using dosage, pH, temperature, initial concentration and Flocculating Speed as variables for both disinfection and coagulation. Results obtained revealed that, the optimum conditions with respect to disinfection (bacteria load removal) were; Dosage=0.4ml, pH=9, Temperature=30°C, Initial concentration=300µm and Flocculating speed=90rev/min, with highest percentage removal of 91% and 82% for the filtrate and powder respectively. For coagulation (turbidity and suspended solid removal), the optimum conditions were; Dosage=0.2ml, pH=5, Temperature=30°C, Initial concentration=633FTU and Flocculating Speed=90rev/min with the highest percentage removal at 84.3% and 80.4% for duckweed filtrate and powder respectively. It is recommended that, duckweed filtrate and powder should be used in water purification for drinking and greywater respectively.

Abstract-The research work is on determination of optimum dosage of soda ash and lime in treating underground water in Makurdi metropolis. In carrying out the work, samples of borehole and well water from five different locations of the study area were analyzed to ascertain the level of hardness and subsequently, determine the optimum values of soda ash (Na2CO3) and lime (Ca(OH)2) that will reduce the water hardness. The locations were, North Bank, Wurukum, Wadata, High Level and Kanshio. The raw water hardness level range from 80mg/l to 200mg/l averagely, which is above WHO (2005) drinking water standards of 75mg/l to 100mg/l. After treatment, the pH was found to range between 6.8 -7.8, while the hardness obtained ranged from 76mg/l to 100mg/l and 20mg/l to 80mg/l for borehole and well water respectively, which is slightly within the WHO (2005) standard. The optimal dosage of Na2CO3 and Ca(OH)2 were determined to be 2.4 ml each with a positive correlation of 0.90. It is recommended that, soda ash be used for the treatment of underground water hardness for safe drinking, while lime be used for other domestic purposes for cost effectiveness.

The research work is on determination of optimum dosage of soda ash and lime in treating underground water in Makurdi metropolis. In carrying out the work, samples of borehole and well water from five different locations of the study area were analyzed to ascertain the level of hardness and subsequently, determine the optimum values of soda ash (Na2CO3) and lime (Ca(OH)2) that will reduce the water hardness. The locations were, North Bank, Wurukum, Wadata, High Level and Kanshio. The raw water hardness level range from 80mg/l to 200mg/l averagely, which is above WHO (2005) drinking water standards of 75mg/l to 100mg/l. After treatment, the pH was found to range between 6.8 - 7.8, while the hardness obtained ranged from 76mg/l to 100mg/l and 20mg/l to 80mg/l for borehole and well water respectively, which is slightly within the WHO (2005) standard.  The optimal dosage of Na2CO3 and Ca (OH)2 were determined to be 2.4 ml each with a positive correlation of 0.90. It is recommended that, soda ash be used for the treatment of underground water hardness for safe drinking, while lime be used for other domestic purposes for cost effectiveness.