In this study, Physico-chemical analysis of 21 brands of sachet water packaged within Zaria metropolis was evaluated to compare their compliance with World Health Organisation (WHO) and Nigerian Industrial Standard (NIS) threshold limits using standard analytical methods. The parameters evaluated include: colour, taste, odour, pH, chloride, potassium, calcium, electric conductivity, oxygen demand (OD), biological oxygen demand (BOD) and total dissolve solid (TDS) while coliform counts were only determined for sixteen brands using standard methods. The results from the laboratory analysis showed that all samples were tasteless, colourless and odourless; most of the physico-chemical parameters conform with WHO and NIS permissible limits except coliform count in which 100% of the sachet did not conform to the WHO threshold limits. Only 25% of sachet water did not conform to NIS threshold limits. The t-test result reveals that there is no significant difference between the sachet water properties with the WHO and NIS standard. The results of this study indicate that sachet drinking water produced or sold in Zaria is relatively of good quality for human consumption but there is need to improve the biological treatment to perfect its portability.

This research analyzes the effects of the use of aquaponics on the metal contents (Cu, Fe and Zn) in water, pakcoy, and tilapia. Fish and plant sampling techniques were conducted randomly while the water sampling was taken at three points: the fish pond, the tank after biofiltering, and the hydroponic tank. Sampling was done 4 times, for 0, 10, 20 and 30 days. The method of wet destruction with aquaregia was used for the preparation of the fish and plant samples. Furthermore, the content of Cu, Fe and Zn metals in water, pakcoy and tilapia was detected using flame atomic absorption spectrophotometer (FAAS). The results showed that the concentrations of Cu, Fe and Zn metals were higher on the 10 th day than on the 0 days. But after the 20 th day and the the 30 th day, the concentrations of Cu, Fe and Zn in the pond water were reduced. The concentrations of Cu, Fe and Zn metals in the fish pond were 0.008mg/L, 0.44mg/L and 0.309mg/L respectively on the 30 th day. According to the Government Regulation Number 82 of 2001, the standard of water quality for fish and plant cultivation for Cu, Fe and Zn concentrations are 0.02mg/L, 0.3mg/L and 0.05mg/L respectively. It was therefore resolved that the Cu metal concentrations obtained has satisfied the standard of water quality, while the concentrations of Fe and Zn metals did not attain the alleged standard of water quality. The highest level of Cu metal in the tilapia fish (Oreochromis niloticus) was 22.94mg/kg and this was ascertained on the 20 th day. The highest level of Zn concentration on day 0 was 157.10mg/kg. Similarly, the highest level of Fe content on the 30 th day was 826.91mg/kg. On the other hand, the highest level of Cu content in the pakcoy plant was 27.82mg/kg, the highest level of Zn content was 210.81mg/kg and the highest level of Fe content was 2583.61mg/kg and this was detected in the analyzed samples on the 30 th day. The study shows that the content of the Cu and Zn levels in the tilapia and pakcoy plants have exceeded the national standard limit according to Decree of the Director General of Drugs and Food Control POM/03725/B/SKVII/89.

To meet the consumption needs of fish and vegetables by utilizing a narrow urban land it can be used an aquaponic system. The aquaponic system is an integration of fish farming with hydroponic cultivation that utilizes the remains of feed and fish waste into nutrients for plants with the help of nitrifying bacteria. In this study used tilapia (Oreochromis niloticus) and Pakcoy (Brassica rapa L). Determination of ammonia, nitrite, and nitrate concentration aims to find the ammonia change to nitrite and nitrate in fish ponds, biofilter, and hydroponic sequences, and their absorption by plants. The ammonia concentration at three sampling points (3.231-8.989) mg/L and has exceeded the threshold of 0.02 mg/L, while for ammonia concentrations in each sample of pakcoy plant (558.563-2,001.659)mg/Kg. The concentration of nitrite (0.008-0.760)mg/L and has exceeded the standard quality threshold of 0.06 mg/L, except in the 0 day water sample sample 0.009 mg/ L and the water sample after the biofilter 0.008 mg/L, the concentration of nitrite pakcoy plant (3.764-12.321)mg/Kg. Nitrate concentration in water sample (1.046-2.275)mg/L, and still below the standard threshold of freshwater aquaculture (20-30)mg/L, nitrate concentration in pakcoy plant (4,890.09-12,864.7)mg/Kg. Ammonia and nitrite concentrations have exceeded the threshold, while nitrate concentrations are still below the threshold.

No abstract

The focus of this empirical study is to investigate the effect of reservoir inflow pattern on hydroelectric power generation in Kainji dam, Niger state, Nigeria. Investigation was conducted using data on reservoir inflow and the amount of power generated for the period of thirty years from Kainji hydropower station. The trends of reservoir inflow for the time frame of study were shown using trend lines. Hypothesis was tested for the relationship between reservoir inflow and the amount of power generated using Pearson correlation coefficient. Analyses on periods with high and low inflow on the amount of power generated was achieved by getting the overall mean of power generated for the time frame of study while comparison was made on the mean monthly power generated and inflow pattern using a trend analysis. The study reveals that the low inflow period in Kainji reservoir is between April and July of each year, with an average inflow of 200m a correlation coefficient of 0.92. It was recommended that the government should encourage the use of other alternative sources of electricity generation in order to meet the growing demand in electricity.