Composite Goodness of Fit in Reaeration Coeffcient Modeling

Determination of reaeration coefficient is an important factor in surface water quality modeling as it determines the efficiency of the Streeter-Phelps model used for predicting dissolved oxygen deficit of any stream. This study compared the efficiency of Atuwara model with ten other reaeration coefficients models by making use of three data sets obtained from river Atuwara during the prevalent wet and dry seasons using composite goodness of fit test which was developed by quantitatively combining statistical and graphical goodness of fit. The eleven tested models were ranked in order of performance. Results show that the four top ranking models were developed through a process that utilized data from multiple streams while models that were developed from data obtained from the test subject alone performed less competitively. The outcome of the study also suggests that the usual practice of selecting the best model based on statistical analysis alone does not necessarily yield the best result and therefore recommended the incorporation of quantitatively analyzed graphs. The paper concludes that selection of the best performing model among existing reaeration coefficient models using the composite goodness of fit may present a cheaper and better alternative to conventional model development approach

Sustainable groundwater exploitation in Nigeria

In this study, a critical review of the groundwater resources history and management in Nigeria was done. The aim was to identify reasons why groundwater is increasingly being exploited in recent times, and to explore ways through which the exploitation could be done sustainably. This was achieved through literature review. It was observed that an estimated 60% of Nigeria’s population get drinking water from ground resources. This high statistic is mostly the resultant effect of infrastructural decay in the potable water supply sector of the country. In Nigeria, just 14 % of the country’s population get regular water supply through piped sources while the remainder of the country’s 162.5 million people draw their water supply mainly from surface and groundwater sources. Groundwater, in Nigeria, is accessed mainly in form of shallow (hand-dug) and deep (boreholes) wells. Well water withdrawal activities are mostly un-regulated and, therefore, the water sources are often subjected to avoidable abuses and pollutions. In particular, rapid urbanization, agricultural and industrial activities are major contributors of pollutions to groundwater sources. Also, unavailability of data such as geographical information on water quantity, hydrology, state of aquifer and withdrawal limits have contributed to the unsustainable use of groundwater in Nigeria. It was recommended that proper regulation of groundwater resources and its protection under the land use act of 1978 could be instrumental to its sustainable exploitatio

WASTE MANAGEMENT AND WATER QUALITY ISSUES IN COASTAL STATES OF NIGERIA: THE OGUN STATE EXPERIENCE

Waste dumping and inadequate waste management efforts are having adverse impact on the environment and humans in Nigerian coastal cities. Nine of the 36 states in Nigeria border the Atlantic Ocean. Twenty-five percent of the Nigerian population is found in the coastal states. These states, with the exception of Lagos, Ogun and Ondo, are more prone to petrochemical wastes arising from petroleum exploration. Field investigations, surveys and literature searches were conducted in order to accomplish the task of this research. Field studies included testing for dissolved oxygen, biological oxygen demand, nitrates, phosphate, total solids and pH

Human Trafficking: The Health of Men Forced into Labor Trafficking in the United States

Human trafficking is a criminal act that occurs globally. It affects both women and men, but most studies have focused on female victims; few have explored trafficked men or their related health issues. Though there are many forms of trafficking, it is believed that most male victims are trafficked as forced labor. Using gender schema theory as a framework, this quantitative study examined archival data to identify the types of trafficking men are subjected to, their health ailments, and how these differ from the health ailments of trafficked women. Archival data from 124 individuals subjected to human trafficking in Florida were analyzed using the Kruskal-Wallis, one-way ANOVA, Mann Whitney U, and Fisher\u27s exact tests. Findings indicated that males were more likely to have been labor trafficked compared to other forms of trafficking, and that labor trafficked persons were not more susceptible to health ailments than were sex trafficked persons. Also, there was a significant difference in health conditions between male and female victims, with females reporting more issues such as malnourishment, skin rash, and anxiety. These findings help to alter the misperception that men are traffickers only by recognizing them to be victims as well. Implications for social change include increased awareness of male trafficking in health care policies and human trafficking prevention efforts

Experience and Reactions to Psychological Contract Breach among Nigerian University Academics

The objective of this study was to find out university academics experiences and reactions to psychological contract breach. In other to achieve this goal 297 academics from two (2) universities located within Benin City, Edo State were selected for inclusion in the study. A total of 554 questionnaires were administered to academic staff from both universities and 297 questionnaires were returned and found useable. The data obtained, due to its nature was analyzed using content analysis and from that analysis we found that academics experienced psychological contract breach in two main areas: the working environment and training & development. The study also found that academics resorted most frequently to “self-help†strategies in order to address breaches of their psychological contracts. We recommended that, among other things, academic institutions take the necessary steps to improve the working conditions of academics

Cadmium And Lead Contents Of Unpackaged Tapioca Exposed For Sale In Selected Markets In Lagos, South West Nigeria

The levels of cadmium and lead in unpackaged Tapioca, a cassava product, consumed as breakfast meal from five selected markets were investigated using the anodic stripping voltammetry.  The levels of cadmium in tapioca ranged from 1.7 to 2.7ug/g, while the lead contents ranged from 5.2 to 7.6ug/g.  Analysis of the results using the t- test shows that the lead level in tapioca samples from Agege, Orile Agege and Oyingbo did not differ significantly (p≤0.05) from each other.  However, they differed significantly from those samples from Oke-Odo and Mushin.  The cadmium levels in Tapioca samples from Agege, Mushin and Oke-Odo differed significantly (p≤0.05) from the samples of tapioca from Orile Agege and Oyingbo.  The level of the contaminants did not exceed the level found in human milk in studies carried out by World Health Organization in selected countries.  The results provide reliable information on the possible dangers arising from the consumption of unpackaged tapioca exposed to contaminants on high traffic motorways. &nbsp

Reaeration Coefficient Modelling: Case study of River Atuwara, Ota, Nigeria

This study was carried out on River Atuwara in Ota, Ogun State, Nigeria with the aim of developing a coefficient of re-aeration model applicable to River Atuwara and other rivers in the Nigerian environment. This was achieved by sourcing for data once every month from 22 sampling locations of interest within a pre-selected segment of the river over a period covering the dry and wet seasons. The data collected include hydraulic data (depth, width, velocity and time of travel) and water quality data such as Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD). Excel Spreadsheet and MATLAB were used for data processing. Regression analysis was carried out where stream velocity and depth were the regressors and the re-aeration constant k2 (as a function of BOD, DO and Temperature) was the dependent variable. A coefficient of re-aeration, k2, (Atuwara re-aeration model) was developed and validated statistically. Its performance was also verified by comparing the model with 10 other internationally recognized models. It was found that even though Atuwara model performed better than Agunwamba model and most of the other well cited models, both Atuwara model and Agunwamba model could be safely adopted for future water quality modelling researches in the Nigerian environment. Results of detailed water analysis of samples from River Atuwara shows high level of pollution hence it is unfit for human consumption without adequate treatment. It is recommended that River Atuwara and similar rivers in the country should be regularly monitored for quality control

Water Quality Modelling: Case study of the Impact of Abattoir Effluent on River Illo, Ota, Nigeria

This report presents results obtained from the investigation and water sampling exercise carried out on the segment of River Illo that passes through Sango in Ado Odo-Ota Local Government Area, Ogun State, Nigeria. The report reveals that while some people used water from the river for domestic, food production and recreation purposes, others discharge their wastes without any form of pre-treatment into it. The multipurpose usage of water from River Illo by local residents thus hinges public health on the self-purification capacity of the river alone. Information on water use and waste disposal practices of the local residents were obtained through direct observation and oral interview of members of randomly chosen households built along the river within a distance of 2km. Single grab samples of water were obtained from the river at the site of an abattoir effluent discharge at distances 0m, 10m, 20m, 30m, 50m and 100m from the point of discharge. A seventh sample was also obtained 10m upstream of the point of effluent discharge to furnish information on ambient conditions of the river prior to pollution while an eighth sample which was prepared by diluting the water obtained at 0m with distilled water (i.e. 25% stream water, 75% distilled water) was included to serve as control sample. All water samples were transported (within 3 hours of isolating them from the river body) to the laboratory for analysis and the results were subjected to graphical, statistical and mathematical analysis. Pollution from the abattoir caused a drop in dissolved oxygen level of the river from an ambient value of 4.6mg/l to 0.01mg/l at the point of discharge. The pollution also caused an increase of 447.5mg/l to 1071.5mg/l in T.S., 0.04mg/l to 4.4mg/l in ammonia, 170mg/l to 670mg/l in BOD, 0.05mg/l to 3.05mg/l in phosphorus, 50mg/l to 1066.7mg/l in alkalinity and 18mg/l to 820mg/l in Acidity. It was also found out that between 30m – 80m downstream of the pollution point, a threat of eutrophication is caused by plants growing in the river path. Despite this obstruction, the river recovered considerably to a D.O. level of 3.9mg/l at 100m downstream. Results from the dispersion modeling shows the self-purification capacity of the river, f, to be 1.1 within 30m distance from the point of discharge and 0.8 between 30m and 100m from the point of discharge. The results from the application of the Streeter-Phelps model showed that the eutrophication occurring between 30m – 80m is interfering adversely with the self-purification processes of the river. The percentage compliance of each of the eight water samples with Guideline Values (GLV) of WHO and FEPA was performed. None of the samples met the minimum requirements for BOD, COD and TSS, which are indicators of pollution. It was concluded that River Illo is being polluted by abattoir effluents discharge thereby exposing the health of local residents who use the water from the river for domestic, recreation and food production purposes to avoidable risks. Suggested actions that could further complement the self-purification capacity of the river were offered

EVALUATION OF WATER QUALITY MODELLING PARAMETERS: TOWARDS THE EVOLVEMENT OF RE-AERATION COEFFICIENT FOR RIVERS IN THE NIGERIAN ENVIRONMENT

This study was carried out on River Atuwara in Ota, Ogun State, Nigeria with the aim of developing a coefficient of re-aeration model applicable to River Atuwara and other rivers in the Nigerian environment. This was achieved by sourcing for data once every month from 22 sampling locations of interest within a pre-selected segment of the river over a period covering the dry and wet seasons. The data collected include hydraulic data (depth, width, velocity and time of travel) and water quality data such as Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD). Excel Spreadsheet and MATLAB were used for data processing. Regression analysis was carried out where stream velocity and depth were the regressors and the re-aeration constant k2 (as a function of BOD, DO and Temperature) was the dependent variable. A coefficient of re-aeration, k2, (Atuwara re-aeration model) was developed and validated statistically. Its performance was also verified by comparing the model with 10 other internationally recognized models. It was found that even though Atuwara model performed better than Agunwamba model and most of the other well cited models, both Atuwara model and Agunwamba model could be safely adopted for future water quality modelling researches in the Nigerian environment. Results of detailed water analysis of samples from River Atuwara shows high level of pollution hence it is unfit for human consumption without adequate treatment. It is recommended that River Atuwara and similar rivers in the country should be regularly monitored for quality contro