PraiseGod C Emenike

Estimation of longitudinal dispersion co-efficient: A review

Abstract Accurate determination of longitudinal dispersion coefficient in rivers or streams is necessary for pollution control and management. This can be achieved through tracer studies and has proven to be a reliable method for measuring pollution spread. However, tracer studies practise which is expensive, time gulping and requiring large labour input have been substituted with empirical approaches thereby reducing the applicability of the dispersion coefficient models generated. This study reviews the various models derived as well as methods associated in the collection of tracer concentration data (measurement) existing in the literature. A sustainable approach to this study was identified and research needs were also listed.

ASSESSMENT OF DOSE INTAKE OF TOXIC ELEMENTS IN GROUNDWATER SAMPLES FROM ABUJA, NORTH CENTRAL NIGERIA

This study measured the concentrations of toxic carcinogenic and non-carcinogenic elements present in groundwater using Inductively Coupled-Plasma Mass Spectrometry (ICP-MS). The concentration values obtained were used to calculate the life average daily dose (LADD) exposure of the people whom rely on groundwater for consumption in Abuja, Nigeria. The highest LADD for the carcinogenic toxic element chromium (Cr) was 2.7 x 10-5 μg kg‒1 day‒1, whereas it was 3.3 x 10-4 μg kg‒1 day‒1 for the non-carcinogenic toxic element lead (Pb), identified in water samples collected by the Water Board. These LADD magnitudes of 10-5 and 10-4 for both carcinogenic and noncarcinogenic toxic elements in groundwater are far below the International Reference Dose according to the United States Environmental Protection Agency (USEPA) in 2008, which has a value of 10-1. The low magnitudes found in water samples may not pose significant health risks to the local population. The relevant authorities should, therefore, continue to monitor the impact of human activities on metal pollution in this area and take effective measures to control contamination of the public water supply

LIFE AVERAGE DAILY DOSE OF RADIUM-226 ON SOME WATER SAMPLES COLLECTED AT GIRI AND KUJE AREA OF ABUJA, NORTH-CENTRAL NIGERIA

226Ra concentrations were studied to represent the radiological risk of groundwater of the Giri and Kuje areas of Abuja, North-Central Nigeria. Two borehole water samples were collected from the Giri and Kuje areas of Abuja with a hand-dug well and Abuja Water Board as control. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the concentrations of radionuclide of 226Ra exposed to the dwellers. The activity concentrations of 226R in groundwater supplies for drinking and domestic purposes ranges from 443

QUALITY ASSESSMENT OF A UNIVERSITY CAMPUS WASTEWATER RESOURCE

Vast volumes of freshwater can be conserved if the practice of re-using wastewater is encouraged. In this study, the quality of wastewater from the Covenant University campus was assessed to determine its suitability for landscape irrigation purposes. The university uses a constructed wetland (CW) method in treating both its black-water and grey-water (wastewater). An estimated 874,081 litres/day of wastewater was generated and treated as of 2013, with nearly all of this volume discharged without being re-used. To assess the suitability of the wastewater for reuse, duplicate grab samples of treated effluent from the CW and from the grey water outlet were assessed for physical parameters such as pH, Temperature, Total Dissolved Solid (TDS), Salinity, Conductivity were analysed using handheld Hanna multi-meter instrument (model HI2040). Also, chemical parameters such as Nitrate, Nitrite, Lead, Nickel, Cadmium, Zinc and Copper were tested using Palintest photometer (model 8000). Moreover, total coliform was checked, using standard laboratory methods. Results indicated that none of the tested parameters exceeded the specified limits by Food and Agriculture Organization (FAO) of United Nations and Environmental Protection Agency (EPA) standards for wastewater reuse. Thus, the treated wastewater in Covenant University was found to be a valuable resource for multiple purposes that can add value other than outright discharge. Thus, it was recommended that appropriate infrastructure be put in place to harness and reuse treated wastewater coming from Covenant University.

EXPERIMENTAL INVESTIGATION OF COPPER REMOVAL FROM AQUEOUS SOLUTION USING MUSA PARADISIACA AS A NOVEL ADSORBENT

The adoption of agricultural waste materials in the removal of heavy metals from contaminated waters has gained more recognition in recent times. This study capitalizes on the production of adsorbents from one of the predominant agricultural waste materials (Plantain Peel) in Ado-Odo Ota, to access its metal-removal efficiency. This work investigated Cu2+ adsorption using activated carbon processed from chemically modified unripe plantain (Musa paradisiaca) peel. Adsorption studies were performed using batch experiments wherewith the influence of pH of the solution, initial concentration, temperature and contact time have been cross-examined. The results displayed a 99.8% removal efficiency of Cu2+ at pH 7.5, 30°C and 150 mg/L concentration. The equilibrium adsorption capacity of unripe Musa paradisiaca peel has been obtained using linear models of Langmuir and Freundlich isotherms. The result is poised to elucidate the metal retention mechanism as a process involving ion exchange as the divalent metal ion binds to the activated unripe plantain peel.

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.

Assessment of KOH-activated unripe Musa paradisiaca peel for adsorption of copper from aqueous solution

Abstract Adsorption of copper ions out of aqueous solution by preparing activated carbon from unripe Musa paradisiaca peel (UmpP) with KOH was investigated. Estimation of the adsorption constants was achieved by adopting the Langmuir and Freundlich models. Results revealed that the adsorption process was fast and equilibrium was reached at 55 mins. The adsorption efficiency was highly influenced by the pH of the solution, and the maximum adsorption was attained at pH 7.5. In addition, an increase in adsorption capacity was observed with increase in contact time and initial copper concentration. The adsorption process was explained by both Langmuir and Freundlich models having R2 value of 0.9977 and 0.9959 at 303 K respectively and R2 value of 0.9922 and 0.9904 at 308 K respectively. The maximum adsorption capacity of KOH-modified UmpP at the specified conditions was found to be 9.980 and 9.766 mg/g at 303 and 308 K respectively. Sequel to modelling the kinetic data, the Pseudo-second-order model gave the best fit with R2 = 0.9990 and 0.9977 at 303 and 308 K respectively, indicating that the adsorption process is restricted to chemisorption. KOH-modified UmpP can serve as an economically and environmentally viable sorbent for the removal of copper from contaminated waters.

WOMEN’S INVOLVEMENT IN THE EVALUATION OF WATER-IMPROVEMENT VARIABLES TOWARDS THE ACHIEVEMENT OF SUSTAINABLE DEVELOPMENT GOALS: ASSESSMENT OF A SEMI-URBAN CITY IN SOUTH-WEST NIGERIA

Target 6 of the Sustainable Development Goals is aimed at the sustainable management of water using different levels of challenges and goals for different countries. The survey presented in this paper involves the distribution of 600 well-structured questionnaires to 340 mapped-out households, as well as personal interviews and group interactions to capture respondents’ perceptions in line with the subject matter. The questions examined variables of analysis pertaining to the level of accessibility, cost perception, sources of water and proposed use of water gotten within Ado-Odo Ota, Ogun State, Nigeria. The outcome from the contributions of respondents was analyzed using the Multinomial Logit model. The Logit result obtained from the survey showed that the responsibility of accessing water within a household lies with the woman, as more women responded in affirmative to that aspect (61.2%). A thorough appraisal of the demographics showed that respondents depend on private sources, which seem expensive to get because the quality of other sources could not be relied on based on the judgment of some physical properties such as smell and colour. After evaluating all logical variables, the results further identified the shortcomings and complications of water service delivery that have caused respondents to lose confidence in government-provided water facilities. To positively improve the SDG metrics, the research highlights positive initiatives such as subsidy, cost recovery, and policy re-visitation to improve water supply access within Ado-Odo Ota.

Analysis of Groundwater Quality in a NigerianCommunity

Groundwater is the most accessed freshwater source in Nigeria. However, the groundwater resource sector of Nigeria is confronted with pollution problems arising from both natural causes and human activities. The current study examines the case of a faith-based campus whose water needs are 100 % serviced via groundwater. The campus accommodates about 15,000 full residents and 400, 000 weekly visitors. The campus water supply is sourced from 15 functional boreholes which are pumped directly into elevated tanks. Four replicate water samples were obtained from four tap points which are supplied by four different elevated water tanks within the campus. The water samples were analyzed for physicochemical contaminants using standard methods. This was done to confirm the potability of the water which is being consumed by residents. Results of the analysis of the groundwater in the study area showed that all the water samples met the minimum requirements of the National Standard for Drinking Water Quality (NSDWQ) for pH, sulphate, nitrate, chloride and Total Dissolved Solids (TDS). However, all the water samples exceeded the NSDWQ limit of 400 mg/L for hardness. Cadmium was also found to exceed the NSDWQ limit of 0.003 mg/L in all water samples while 50 % of the water samples slightly exceeded the 0.5 mg/L limit for Iron. The presence of cadmium in most of the water sample suggests that there is high risk in consuming water from these boreholes. Due to the life-threatening effect of cadmium on humans, it was concluded that water from the study area should not be consumed without treatment.

Assessment of Gravel Properties Sourced within Oyo North Senatorial District: Case Study of Ogbomoso

The study evaluated the properties of gravel aggregate sourced within Oyo north senatorial district for concrete production in place of crushed granite crushed at exorbitant cost since characteristic properties show significant reflections on the qualities of gravel aggregate used and also play major role in determining the properties of hardened concrete.Samples of gravel from four commonly used borrow pits: Aroje, Bolanta, Sunsun and Olomi sites were obtained and tested for Aggregate Crushing Value (ACV), Aggregate Impact Value (AIV), Specific Gravity, Water absorption Capacity, Bulk Density, Moisture Content and Particle Size Distribution.On the average the results of the observation for the selected four locations were 22.56 g, 28.17 g, 33.37 g and 40.19 g for Aggregate Crushing Value (ACV), 2.44 g/ml, 2.53 g/ml, 2.57 g/ml and 2.62 g/ml for Bulk density, 0.17 %, 1.43 %, 2.42 %, and 2.48 % for moisture content, 2.02 %, 2.92 %, 2.00 % and 3.15 for water absorption, 2.52, 2.63, 2.60 and 2.55 for specific gravity, 41. 55 %, 45.25 %, 45.59 % and 47.08 % for aggregate Impact respectively.The study revealed that, gravel aggregates from Aroje has superior properties over those of Sunsun, Bolanta and Olomi as compared with coarse aggregate properties in BS 812: 1995 and BS 882: 1992. It is hereby recommended for coarse aggregate in concrete production.