Water Treatment

The production engineering department of the University of Benin has often relied on existing water supply from the faculty sunk borehole. This water has been investigated through physiochemical and biological testing to be below standard required quality for drinking. This has necessitated the development and installation of a water treatment for purification and dispensing facility in the departmental Annex of production engineering for safe sustainable water utilization. A conceptual design of the water treatment and dispensing facility was carried out and it comprises of cylindrical tanks stacked with one of the tank containing coarse aggregates of gravel, rock sand, fine aggregate of river sand, and activated carbon (charcoal) all separated with a filter mesh in the cylindrical tank. The other tank contains the clear water already treated by sedimentation tank containing the aggregated materials Tests and performance evaluation of the developed water treatment facility showed that that the volumes of samples of water taken from the water treatment and dispensing facility had minimal variation from one another. The samples had most volumes around the 50cl mark, while others were around 49cl sometimes successive difference of 0.1cl. The little variation in the volumes is due partly to excess drop in pressure of the reservoir water. The variance is 0.24 which is a mean of the respective deviations of the volumes. This value of the variance is very minimal, showing that the machine was able to discharge given volumes of water with considerable accuracy. The observed range of BODs for the treated water was (3.20mg/L to 3.88mg/L). Electrical conductivity values ranged from 18.00 to 65.00S/cm. It was inferred that there was no significant change in the pH value during the observation period; the observed values were in the range 6.9 to 7.5 for both samples of water before and after treatment. The physio-chemical characteristics of water samples in the study area suggested that there was no harmful
chemical contamination in both samples of water.

The influence of dye concentration, adsorbent dosage, and contact time on the % removal of methylene blue dye (textile effluent) from aqueous solution was optimized and evaluated using a three-variable Box-Behnken design (BBD) in combination with response surface methodology (RSM). Coconut shell was utilized to make the adsorbent, which was then activated with H3PO4 after being carbonized at 600°C for an hour. Three variables dye concentration (50–200 mg/l), adsorbent dosage (g/100 ml), and contact time (10–60 mins), were varied to treat the dye solution. The responses of the linear and quadratic models that were developed for % dye removal from aqueous solution were significantly influenced by all three parameters, according to a statistical analysis of the data with p < 0.0001, the models were significant and demonstrated a strong fit with the experimental data. The adsorbent dosage and contact time had a positive impact on the percentage of dye removal. The process was optimized, and the maximum dye removal of 82% was attained at optimum dye concentration, adsorbent dosage, and contact time of 125 mg/l, 0.55 g/100 ml, and 35 min

In rural areas, water contamination remains a major public health concern, exposingresidents to chemical and microbiological pollutants that can cause severe illnesses. Many households rely on untreated water sources such as wells, boreholes, and rivers, which often contain pathogenic microorganisms and elevated levels of heavy metals exceeding recommended safety limits. This study evaluates boiling as a low-cost, effective domestic water purification method, alongside other household treatment options such as filtration, coagulation, chemical disinfection, and distillation. Water samples were collected from the Obazagbon Community and analyzed in the laboratory to assess physico-chemical and microbiological parameters both before and after treatment. A multi-criteria decision analysis (MCDA) framework was applied to rate each purification method based on cost, effectiveness, feasibility, simplicity, sustainability, and accessibility. The results demonstrated that boiling significantly reduced microbial contamination, including total coliforms and E. coli, bringing bacterial counts well within the acceptable limits set by WHO and NSDWQ. Specifically, total coliform counts decreased from 149 CFU/ml (Sample A) and 153 CFU/ml (Sample B) to non-detectable levels, and E. coli was completely eliminated from the treated samples. In terms of chemical pollutants, boiling had limited impact. Levels of dissolved metals such as zinc (1.738 mg/L initially reduced to 1.520 mg/L), iron (0.798–0.801 mg/L), cadmium (0.015–0.018 mg/L), and lead (0.063–0.065 mg/L) remained largely unchanged after boiling, highlighting that thermal treatment primarily targets microbial contaminants and cannot remove dissolved chemical pollutants. Physicochemical parameters such as pH remained within safe limits (6.20–6.23 post-treatment). The persistence of metals is attributable to the geological composition of water sources and potential contamination from human activities, including agricultural runoff, poor waste management, and corroded plumbing systems. Overall, the study confirms that boiling is a highly effective method for microbial disinfection

This study investigated the optimization of granulated groundnuts (Arachis hypogaea) as a natural coagulant for water treatment, compared with the conventional chemical coagulant, alum. The research was motivated by the increasing need for sustainable and eco-friendly water treatment methods, as chemical coagulants such as alum have been associated with high residual ion concentrations and potential health concerns. The study aimed to determine the optimal operational conditions—coagulant dosage, stirring speed, and flocculation time—that yield the best water quality in terms of turbidity, pH, conductivity, and total dissolved solids (TDS). Response Surface Methodology (RSM) using Design-Expert software was employed to model and optimize the coagulation process based on experimental data from jar tests.

For the granulated groundnut coagulant, optimal conditions were achieved at a stirring speed of 400 rpm, stirring time of 2.37 minutes, and dosage of 1.00 mg/L, resulting in predicted responses of pH 6.61, conductivity 221.98 µS/cm, TDS 121.30 mg/L, and turbidity 7.86 NTU. In comparison, alum showed its best performance at a stirring speed of 400 rpm, stirring time of 7.06 minutes, and dosage of 2.96 mg/L, yielding a pH of 6.50, conductivity of 1392.24 µS/cm, TDS of 825.65 mg/L, and turbidity of 4.93 NTU. While alum produced slightly lower turbidity, it significantly increased conductivity and TDS, indicating higher residual salts and poorer overall water quality compared to granulated groundnut.

The findings demonstrate that granulated groundnut is an effective, biodegradable, and low-cost alternative to alum, providing satisfactory turbidity reduction, excellent ionic quality, and near-neutral pH at lower dosages and shorter flocculation times. The study concludes that groundnut-based coagulants can serve as a sustainable option for small-scale and rural water purification systems and recommends further research on microbial removal efficiency and large-scale application to enhance practical adoption in eco-friendly water treatment.