Determination and Remediation of Selected Polycyclic Aromatic Hydrocarbons in Petroleum Contaminated Water

Determination and remediation of pollutants such as polycyclic aromatic hydrocarbons (PAHs) have not being fully regulated in Nigeria; hence  contamination of surface water by such pollutant is a major concern. This study was designed to determine the level of selected PAHs in petroleum contaminated water using spectroscopic techniques and the efficacy of activated carbons made from Bambusa vulgaris and Oxytenanthera  vabyssinaca. Bambusa vulgaris and Oxytenanthera abyssinaca were carbonized at 350OC and activated with Phosphoric acid (CBV350OC H3PO4) and Potassium chloride (COA 350OC KCl) as dehydrating agent respectively. The adsorbents were then used to remediate PAHs in petroleum contaminated water. Liquid-Liquid extraction procedures were used for extracting selected PAHs from sampled solutions. The batch experiment was performed to study the adsorption capacity of adsorbents at 5hrs contact time. Analysis of PAHs concentration for each sampling day was determined by GC-MS. Total PAHs in simulated wastewater did not show a clear trend, contrary to the expectation that there should be a progressive increase with time due to photolysis or photodecomposition of compounds or PAHs. COA 350OC KCl showed a range of 6.2-19.3% removal efficiency of each selected PAH with a total percentage efficiency of 27.7-70.8 for all days. For CBV350OC H3PO4 removal efficiency ranged from 10.26-19.30% for each selected PAH and a total efficiency of 50.8-100% for all selected PAHs for the 4 days intervals. The experimental result showed that adsorbent made from Bambusa vulgaris and Oxytenanthera abyssinaca and activated with H3PO4 and KCl as dehydrating agentrespectively can efficiently adsorb the selected PAHs in contaminated water. The study also revealed that PAHs in contaminated water increases with time due to photodecomposition, thus necessitating their treatment on time

Efficacy of Hibiscus Cannabinus L. (kenaf) Crude Seed Powder and its Methanol Extract in Water Purification

The efficiencies of hibiscus cannabinus (kenaf) powder and methanol extract were studied in water purification. Two turbidity levels namely, high (160NTU) and low (49NTU) were considered. The water samples were taken from an open pond used for irrigation farming in Custom area of Maiduguri, Nigeria. In this study, the powdered cannabinus was discovered to be more effective in removing high turbidity water, with an efficiency of 96.0% against the extract with 85.6%. However, in low turbidity water, the methanol extract performed better, with a turbidity removal efficiency of 89.4% compared to 84.4%, if the cannabinus powder is used. Another parameter studied was the pH of the water which remains unaffected after the treatment at 7.0. The outcome of the performance of this natural coagulant and alum when compared indicated that alum also performed better on high turbidity water than low turbid water with a removal efficiency of 98.8% and 95.7% respectively. Alum slightly affected the pH of the water from original value of 7.0 to 5.5, which makes the water more acidic after treatment. It appears that natural coagulants of plant origin remain the best option engineers are left with, if the current emphasis on millennium development goal on clean water supply for all is to be achieved. Keywords: , Cannabinus, Coagulation, Water Purificatio

Observed Trend of Changes in Relative Humidity Across North-East Nigeria (1981-2010)

Monthly relative humidity (RH) data for 6 stations in North-east Nigeria were provided by the Nigeria Meteorological Agencies. Mean RH variabilities, and trends calculated by the Mann-Kendal method are analyzed. The annual regional mean of RH ranged between 47.5±20.6%, with a clear maximum (62.5%) in Taraba and minimum (36.9%) in Borno. Extensive analyses of trends in mean monthly and annual relative humidity were examined for north-east Nigeria, for the period 1981 to 2010. Regression and analysis of variance were used to illustrate trends and calculate mean and annual rate of change. Results showed an inconsistent pattern of trend and a statistically significant stable increase in RH across locations. Keywords: Trend, Changes, Relative humidity, North-east Nigeri

Modeling Trends of Temperature Effects on Water Level of Rivers in N/E Nigeria

This study investigates temperature variabilities in N/E Nigeria using observations of temperature (0C) from 6 stations from 1981-2010 (30years). Trends in annual and seasonal temperature series were modeled using Mann-Kendall test. The analysis revealed  significantly higher (P<0.01) in April compare to all the other months with overall  mean temperature ranged between 20.2 - 31.80C among all the locations  over months and years. There was significant increase of 0.380C (positive trend) in temperature in all studied area except Taraba. Each degree rise of temperature of 0.740C (Gombe), 0.120C (Adamawa), 0.380C (Yobe), 0.530C (Borno) and 0,690C (Bauchi) and decrease 2.050C (Taraba) lead to a reduction and increase in water level by 78.77, 19,10, 74.26, 79.62, 20.65 and 209.29 mm  respectively. Analyses of decadal trends in the time series further suggest a sequence of alternately decreasing and increasing trends in mean annual temperature in Nigeria during the study period. Keywords: Modeling, Temperature, Water Level, Rivers, N/E Nigeria

On the Effect of Hydraulic Retention Time and Loading Rates on Pollutant Removal in a Pilot Scale Wetland

This study examines the potential of Coix lacryma jobi commonly known as Job tears as a wetland plant, and the effect of short Hydraulic Retention Time (HRT) and loading rates on the treatment efficiency of a vertical flow constructed wetland.  Effluents from an anaerobic lagoon system were collected and used as influents for the constructed wetlands. The influents were subjected to 3, 5 and 7 days HRT and 43.73 and 19.91 m3/m2/day loading rate, over a period of 6 weeks. Results from the study shows that the control cell in the system was effective in the removal of phosphorus, (PO4), Ammonia, Ammonium, COD, TDS, DO, and TSS at the higher HRT of 7 days. Similarly, the level of treatment increased as a result of higher HRT, except for the pH which showed no significant difference. Loading rates of 19.91 m3/m2/day at 7 days HRT was effective in the treatment of phosphorus, PO4, COD and TSS with removal efficiency of 89.1, 84.4, 92.0 and 61.3 % respectively. Parameters such as NH4+-N, NH4, NH3, TDS showed significant removal by the wetland system at a loading rate of 19.91 m3/m2/day and HRT of 7 days.  Coix lacryma jobi as a wetland plant, at HRT of about 7days and much lower loading rates is capable of removing pollutants in wastewater