PREDICTING DEGRADATION WITH BIOCHEMICAL OXYGEN DEMAND IN DISINFECTANT-POLLUTED SEWAGE

Most households frequently make use of disinfectants to annihilate infectious bacteria present in toilets and bathrooms. Unfortunately, some of these bacteria may be required for the degradation of sewage in the septic tank system (STS). This paper investigates how the performance (degradation capacity) of sewage will be affected by the inharmonious addition of disinfectants with biochemical oxygen demand (BOD) as the predictor. With a clean 50-litre container, a sewage sample was collected from a waste stabilization pond situated in a Nigerian Tertiary University, transported to the sanitary laboratory in the Department of Civil Engineering, University of Nigeria, Nsukka, and poured into five 4-litre white containers. Different doses of disinfectants – 0.5 ml, 1 ml, 1.5 ml, 2 ml, and 2.5 ml, were simultaneously added only at the initial day of experimental setup under aerobic conditions, and the pH, dissolved oxygen (DO), disinfectant dose, chemical oxygen demand (COD), and BOD were measured every three days for three weeks. Multivariate analysis was performed on the explanatory variable – pH, DO, disinfectant dosage, and COD – using e-Views 8.0, which revealed that the continuous addition of disinfectants to sewage inhibits its degradation, thereby resulting in increased organic loading within the STS, and may further lead to septic tank failure due to shock loading and a major source of ground water been polluted with emerging contaminants

MEASUREMENTS OF SEASONAL VARIATIONS OF RADIOACTIVITY DISTRIBUTIONS IN RIVERINE SOIL SEDIMENT OF ADO-ODO OTA, SOUTH-WEST NIGERIA: PROBABILISTIC APPROACH USING MONTE CARLO

The radioactivity levels were measured using a hand-held gamma-ray survey meter and NaI (Tl) based gamma spectroscopy to evaluate the seasonal variation of radioactivity levels in the riverine area of Ado-Odo Ota. The measured iso-dose map reported higher gamma dose rate of 79 nGy/h, approximately 34% higher than the world average of 59 nGy/h. The values for U-238, Th- 232 and K-40 activity levels ranged between 29.9 and 21.6; 103.2 and 31.2; 802.2 and 233.5 with mean values of 26.1, 55.6 and 499.3 Bq/kg, respectively. According to the mean, 5th and 95th percentiles of the probabilities using theMonte Carlo simulation, the Radium equivalent activities and the absorbed dose rates are within their respective recommended limits of 370 Bq/kg and 84 nGy/h. This study could be used to monitor dose rates and radiological risks for the areas covering the small area (Ado-Odo Ota) to the larger area (West African Region) as baseline data

Sustainable nano-sodium silicate and silver nitrate impregnated locally made ceramic filters for point-of-use water treatments in sub-Sahara African households

The poor access to water quality for Nigerians has pushed for the designing of new trend silver nitrate impregnated locally made Point-Of-Use (POU) ceramic filters to enhance water purification efficiency for household use. This study utilized silver nitrate-molded ceramic filters prepared with Kaolin from Owode, silt soil, sodium silicate, sawdust, and distilled water in three varying proportions to ascertain pollution removal efficiencies. Heating was carried out by firing the filters at 900 �C and further preheating at 400 �C after dipping in silver nitrate solution. Silver nanoparticle and dissociated particle discharge from filter pot painted with 0.03 mg/g caseincovered nAg or AgNO3 were estimated as an element of pH (5–9), ionic strength (1–50mM), and cation species (Naþ, Ca2þ, Mg2þ). Silver delivery was constrained by disintegration as Agþ and resulting cation exchange measures, paying little heed to silver structure applied. Water analysis for both heavy metals (Pb and Cd) and microbial load (E. coli) evaluated, corroborate the maximum removal efficiency. It was observed that kaolinsawdust with the Silver nitrate filters showed a constant and effective removal of both heavy metals and disinfection of microbial loads. The minimum flow rates observed were 4.97 mL/min for batch filter used for Iju River water sample one (AF1) and 4.98 mL/min for batch filter used for Iju River water sample two (AF2) having porosity 49.05% and 50.00%, whereas the 5 mL/min higher flow rate was used for batch filter from borehole water sample one (BF1) and batch filter used for well water sample two (CF2) with porosity of 50.00%. Significantly, the results obtained show that the filters are suitable for point-of-use application in both the urban and rural areas of developing countries such as Nigeri

Integration of Magnetic Data and Geo-Spatial Analysis for Characterising Aquiferious Yields in New Estate, Covenant University, Ota, Ogun State

This study was conducted to understand the possible causes of abortive boreholes along the New Estate in Covenant University. The conceptual model predicted the two groundwater characteristics of weathered and the unweathered zones. The V-shape curve revealed two groundwater anomalies with high and low curves. The peak anomaly indicates the higher resistivity, presumed to be the geological structures of unsaturated features in the area. The sink V-shape curve indicate an anomaly with groundwater features, presenting low resistivity values attributed to be water bearing formation that will be viable for groundwater potential. The Iso-resistivity contour map identified possible groundwater features. The first Iso-resistivity column is a region of aquitard with a semipervious in nature that could transmit water in a slower rate. The second groundwater feature in column 2 is a perch aquifer that could enhance the main aquifer due to interconnectivity and pore pressure of downward-upward migration in confined hydrogeological aquifer setting. Column 3 depicts a complete impermeable feature of aquifuge or aquiclude of subsurface structure with rich in clay sediments or stratum of sediments found at the depth range of 30 m to 270 m. The forth groundwater column indicates a promising water bearing formation, probably sandy in nature with a depth range of 210 to 300 m and thickness of about 90 m. The spatial analysis identified the two locations along the survey areas to be suitable for productive boreholes as well as the trending of the groundwater in the area to be Northwestern Southeast direction. Consequently, the model could be a guide to organize site data, understand site processes and screen for applicability of drilling. These multiple methods of geophysical, spatial analysis and conceptual model could be used a tool for mapping hydrocarbon bearing formation

Compatibility of Electromagnetic (EM) Method and Geospatial Analysis for Identifying the Vulnerable Building Zonation in Coastline Area of Ado-Odo Ota, Ogun State, Nigeria

Collapsing of building incidents have been reported all over the world and seems to be commonespecially in sedimentary terrain of the coastal plain sand of Ado- Odo Ota which has the same subsurface features as the Lagos that experience regular building collapse. This building collapse is attributed to several causes. The reasons that have been identified, have added little or no impact on reducing this environmental disaster. This study presents the strength of emerging and existing geophysical tools for near-surface structural studies. The aim is to reveal the recent technical development on improving field surveys to minimize building collapse. Data acquisition using electromagnetic (EM) methods which are known for fast mapping of near-surface spatial variation as well as obtaining the subsurface vertical variation in electrical conductivity was adopted. The acquired spatial and attribute data was introduced in a GIS environment with different thematic vectors/layers created by digitizing the satellite image of the study area. The GIS digitizing was to geographically trace the acquired data with accurate coordinates from the obtained EM field data with the thematic layer representing the features such as weak zone and competence zones that can hold buildings. A transverse was taken in a strategic positions considering the regional features with 10 m spacing to cover the marked stations. It revealed the layer depths range from 0.37 to 1.64 m with the much competence layer found to be about 1.64 mbeyond which may be the thick clay Ilaro formation that underlies the recent formation. The weathered shear zone at the depth of 0.37 m may be the recent lithoral deposits which is geotechnically and geologicallyunstable and proximity to active faults of ruptured geomorphology of the building zonation

Significance of using electromagnetic (EM) method for groundwater investigation in Sedimentary and Basement terrains: a review

This review article briefly explores the significance of electromagnetic method among other methods used in groundwater investigation. Groundwater investigation can be carried out using various methods such as seismic, magnetic, electromagnetic (EM), electrical resistivity, gravity, remote sensing. Each with its peculiar implication. This paper discusses the effectiveness of EM in detail subsurface investigation for groundwater exploration through an extensive review of the literature. Relevant literatures within the last three years were considered to understand the groundwater features using the EM method over other techniques. Studies using other methods were also examined to compare their reliability in groundwater studies to EM method. This study discovered that the EM method is cheaper, faster and of higher precision in identifying groundwater bearing formation and possible structural control of which the rest technique do not posess such attribute. On this note, there should be a growing interest in the use of EM techniques for groundwater mapping, which gives credible and classification of structural features of both basement and sedimentary terrain groundwater characteristics

Significance of using electromagnetic (EM) method for groundwater investigation in Sedimentary and Basement terrains: a review

This review article briefly explores the significance of electromagnetic method among other methods used in groundwater investigation. Groundwater investigation can be carried out using various methods such as seismic, magnetic, electromagnetic (EM), electrical resistivity, gravity, remote sensing. Each with its peculiar implication. This paper discusses the effectiveness of EM in detail subsurface investigation for groundwater exploration through an extensive review of the literature. Relevant literatures within the last three years were considered to understand the groundwater features using the EM method over other techniques. Studies using other methods were also examined to compare their reliability in groundwater studies to EM method. This study discovered that the EM method is cheaper, faster and of higher precision in identifying groundwater bearing formation and possible structural control of which the rest technique do not posess such attribute. On this note, there should be a growing interest in the use of EM techniques for groundwater mapping, which gives credible and classification of structural features of both basement and sedimentary terrain groundwater characteristics

Spatial distribution of gamma radiation dose rates from natural radionuclides and its radiological hazards in sediments along river Iju, Ogun state Nigeria

This study assessed the radioactivity level of Iju River sediments and its associated radiological risks exposure to human. Gamma absorbed dose rates were measured using a portable gamma spectrometer at an interval of 50 m between each point (Model No:RS-125 manufactured by Canadian Geophysical Institute). The measured absorbed gamma dose rates range from 22 to 59 nGy/h with the highest value noted in site 13. The mean activity concentrations of U-238, Th-232 and K-40 from Iju river sediments were 24.1 ± 0.4 Bq/kg, 35.2 ± 1.1 Bq/kg and 501.0 ± 11.1 Bq/kg, which were lower than the world average values of 32 and 45 for U-238 and Th-232 by 25% and 21% and higher than 412 Bq/kg for K-40 by a factor of 0.22 (22%).•This highest value of K-40 found in site 6 may be due to the presence of feldspartic minerals buried in the sediments.•Consequently, the radiological hazard indices were below the permissible limits except the mean value of 28 × 10-2 for excess lifetime cancer risk (ELCR) for the samples collected in site 6, which is higher than the average world value of 0.29 × 10- 3 by a factor of 0.03.•The regression model indicates that Th-232 attributes more radioactivity impacts on the soil sediments than the contributions of U-232 and K-40, as such, presumed to be the radionuclide parameter controlling the depositional process in the region

Toxicity Risks of Selected Heavy Metal on Dwellers from Building Materials Used in Nigeria

Chemical toxicity risks from 14 different brands of building materials such as Cements, tiles, marbles and sands were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This study is aimed at determining the risk exposure to dweller of different age groups. The digested samples analysed using ICP-MS for the concentrations of Cr, Pb, Zn, Ni, Fe, As and Cd varies from 10 to 183, 8.96 to 68.70, 35.4 to 733.7, 14.4 to 690.5, 0.95 to 4.64 and 0.7 to 14.7 mgkg-1 respectively. Statistical Analysis showed that 44% of the Concentrations of Toxic metals measured in the building material samples come from Ni, the scree plots of dermal and inhalation risks exposure to children aged from 0.5 to 11 years showed sharp drop after Ni metal compared to adult with ages ranges from 12 to 70 years where the drop is steady from the first factor. This indicated that Adults are not over-exposed compared to children to these heavy metals. The High factor value of 2.786 was seen in Goodwill Verified. Tile High factor scores were discovered from the exposure of children to both dermal and inhalation risks compared to the Adults. Some of these concentrations and risks exceed the permissible limits of the European Regulatory Standards and USEPA. Significantly, these chemical toxicity risks of heavy metal contents in the building materials may pose health risks on dwellers especially the under-aged children

Health implication of anion contents in different brands of bottled water samples consumed in some parts of south west Nigeria

In recent time, many bottled water factories in Nigeria are producing water for consumption without standard operation procedures for quality water treatments. Twenty-one samples of different brands of bottled water samples were purchased in and around three densely populated states in Southwest Nigeria. The concentrations of phosphate, nitrate, chloride and nitrite anions in the bottled water samples were analyzed using ascorbic acid method, UV–visible spectrophotometry and argentometric titration. Statistically, the regression analysis indicates that nitrate correlated with nitrite and the significance F value of 1.7 × 10–3 which is lower than the critical value of 5 × 10–3 with p-value of 1.7 × 10–3 also in good agreement. The principal component analysis strongly revealed that high factor scores of nitrite may be due to Aquarite bottled water with a combined contribution of about 65% in all the nitrites found in the 21 samples. The value of 0.80 mg L–1 for nitrite in Aquarite exceeds the World Health Organization, European Economic Community and Standard Organization of Nigeria guidelines by factors of 4, 1.6 and 4, respectively. The anion contents in Nirvana bottled water were found to be lower than the International Reference Standards. The exposure dose, lifetime average daily dose and hazard quotient from the bottled waters were below the permissible limits. This study suggests the need for greater awareness of the risks of anion contents in drinking water, and the appropriate authority should consider the constant increase in production of untreated or poorly treated bottled water as well as the global growth in environmental pollution