An assessment of the effect of industrial pollution on Ibese River, Lagos, Nigeria

This paper deals with pollution aspect of environmental management and monitoring of the river for its sustainable development. The water quality assessment of Ibese River, which is the principal river of the Igbogbo Abayeku Areas of Ikorodu in Lagos, was performed. Assessment was undertaken according to different physical and chemical parameters including biological oxygen demand (BOD), dissolved oxygen (DO), electric conductivity (EC), total dissolved solids (TDS), alkalinity, acidity, total hardness (TH), grease content, major cation and anion, and some heavy metals. Results showed that the river, which was of good water quality at its upstream, in terms of the aforementioned parameters, becomes progressively polluted by the waste materials discharged along its course. A general downstream trend of increase in organic and inorganic pollution was declared. Thus, Ibese River currently faces a number of serious environmental and ecological challenges. Urbanization and industrialization of the watershed at Ibese area in Ikorodu contributed to the water quality deterioration with regional consequences on the aquatic ecosystem and on the health of the downstream’s user groups. This synergetic effect is of concern for the sustainable use of the resources.Key words: Nigeria, Ibese River, water pollution, major cation and anion, heavy metals, water quality deterioration

Assessment of the effects of cadmium and lead on pH and cation exchange capacity of soil under different plant canopy in the tropical wet-and dry climate

The effects of heavy metals pollution on agricultural produce can not be over emphasize. To estimate the effect of heavy metal on pH and Cation Exchange Capacities of soil on incubation, relationships between availability of metals in soil after contamination were investigated for a range of soils and metals. Three concentrations (0 mg/kg, 2 mg/kg and 5 mg/kg) of lead and cadmium were added as nitrate solution as single and combine treatments to six soil samples under different plant canopy. The soils-metal were incubated at field capacity for 8 weeks under 250C. The exchangeable bases in soils were determined in IM ammonium acetate (pH 7.0) extract by FAAS and pH by pH meter with a combination electrode. The treatment is arranged in randomised complete design each in triplicates. The pH decreased from 7.02 to 6.70 and 6.63. Cation Exchange Capacities decreased from range of of 6.62 to range of 4.71 and 3.10 C mol kg-1 under single and combined treatments respectively for the six locations. These results enable us to understand natural attenuation of metal contamination and also to assess the risk of soil contamination by determining effects of metals reactions with CEC and pH in 8-weeks incubated soils after artificial contamination.Keywords: heavy metals, Incubation process, pH and CE

Variation of interception loss with different plant species at the University of Agriculture, Abeokuta, Nigeria

Interception studies of six plants groups were carried out at the campus of University of Agriculture, Abeokuta in Nigeria, using three different sample sites. These sites were the Arborea plantation, cashew plantation and College of Environmental Resources Management premises of the University. The field work was carried out between 15th June and 28th September, 2009. Of the 22 rainfall events recorded for each plant species, at least 13 produced measurable through fall and stem flow and a maximum of 18 measurable records. Through fall showed a very strong linear correlation against daily rainfall for different plant species. The r2 values varied between 0.841 (Teak) to 0.963 (Gmelina). This trend also followed for stem flow since without rainfall no stem flow. This was not the case for interception loss which showed only a moderate correlation against rainfall amount for each plant species with r2 value ranging from 0.058 (Teak) to 0.716 (Neem). This implied an inverse relationship between interception rate and rainfall amount. Interception ratio for coniferous plants was more than deciduous plants, both having average values of 32.01 and 26.54% respectively when interception loss was considered per storm or event. But when considered at the end of observation, deciduous plants had more interception ratio than the coniferous plants with average interception values of 26.54 and 32.01% respectively. At the end of the observation, the interception loss for each plant, Pinus leuceana sp, cashew, Neem, Gmelina and Teak were 18.77, 21.04, 31.96, 26.16, 11.1 and 38.05% respectively. The values changed when considering average interception loss per storm and the values for the plants species as arranged above were 28.60, 30.18, 31.96, 37.26, 17.78 and 29.89% respectively. This showed that interception loss varied from one plant species to another. With these, one will know which can best be used for conservation purpose.Key words: Through fall, stem flow, canopy

Geographical information system (GIS) application for planning and improvement of public water supply in Ota, Ogun State, Nigeria

Geographical information system (GIS) technique is a useful tool for spatial analysis which has not been fully exploited in solving water issues in Ota hence the study. The study applied the tool of GIS in the planning and improvement of water supply system in Ota, Ogun state. This study harnessed the synergy of GIS and engineering designs to proffer an acceptable solution to the problems of water supply in the study area. Primary data generated on the field with GPS and spatial information were analysed with the aid of GIS to produce contour pattern and Digital Elevation Model (DEM) in form of maps. The study noted that the population would increase to almost double the present population by the year 2040 invariably resulting to an increase in water demand of the population beyond the capacity of the existing water supply facilities. Results also showed that water demand by the projected population by year 2040 will increase to 68.37 million litres per day while the existing facility has the capacity to produce about 9.2 million litres per day. Maps produced by the study included Contour, Digital Elevation and Existing and proposed pipeline network maps. These maps made available more information which can then be used for improving the water supply system. The study proffered a lasting solution through design of water scheme with capacity large enough to cater for water requirement of the population for the next twenty-five years irrespective of variation in water need of individual residents in the area with designs to improvedistribution system through extension of pipelines and identification of various locations for service reservoirs.Keywords: GIS, design period, per capita

Assessment of Nutrient Concentration in Sokori River, Southwest Nigeria

Water management planners are facing considerable uncertainties on future demand and availability of  water partly due to concentration of nutrient leading to excessive unsightly growth of aquatic plants and  algal bloom in rivers. This study was carried out to assess the trend of nutrient concentration in Sokori  stream in Southwest Nigeria. The selected nutrients determined in the stream were nitrate, sulphate and phosphate, dissolved oxygen and biological oxygen demand. Water samples from 10 sampling point at  100m interval were examined to assess the variation in concentration of nutrients along the stream using  standard method. Descriptive statistics was used in data analysis. The result showed that high nutrient concentrations were established at the middle section of the stream. It is obvious that sulphate has the highest concentration (3.60 Mg/l), followed by phosphate (2.13 Mg/l) then nitrate (0.89 Mg/l). However, the nutrient concentrations in the stream were below the acceptable limit set by the World Health  Organization. Furthermore, it was observed that where the nutrients concentration (PO4 = 5.16 Mg/l, SO4,= 9.78 Mg/l, NO2 = 1.46 Mg/l) and the BOD (10.24 Mg/l) were highest at the mid – section of stream, while the DO concentration (3.63 Mg/l)  lowest indicating concentrated aquatic life (macro and micro-organisms) activity. Nutrient enrichment leads to excessive growth of primary producers as well  as  heterotrophic bacteria and fungi, which increases the metabolic activities of stream water leading to a depletion of dissolved oxygen. The low discharge of stream  and its fairly flat terrain nature also influenced the metabolic activities in the mid- section of the stream although there was no evidence of accumulation of nutrient leading to eutrophication risk.Keywords: Nutrients, Sokori stream, Phosphate, Nitrate, Sulphate, Runof

The Effects of Storage on Sachet Water Quality in Ogun State, Nigeria

The purpose of this study is to investigate the effect of storage on the physicochemical status and bacteriological quality of sachet water produced and sold in  Abeokuta metropolis, Nigeria. Ten brands of sachet water were collected within 24 hours of production and stored at ambient temperature. Sub-samples were drawn from the stock samples immediately for physico-chemical and microbiological analyses and after two months. Physical parameters were determined by instrumental methods. Cationic and anionic constituents were determined by standard titrimetric and spectrophotometric methods, trace and heavy water were determined by Atomic Adsorption Spectrophotometer. The study revealed that all the brands of water analyzed were physically and chemically wholesome and met the WHO standards. Five brands (50%) of the water had total viable and coliform count above the recommended count of 100cfu/m and zero cfu/ml, respectively. pH values increased in all brands to acceptable WHO limits within 2 months of storage except for sample 3 and 4 which decreases below the acceptable limit.  Majorly dissolved oxygen and nitrate values decreased through the investigation period. Total and faecal coliform appeared in 50% of sachet water samples  analyzed immediately after production and were no longer detected after storing for two months except for sample 4. Results of the experiment indicate that 60% of the brands analyzed met the WHO guideline limit for drinking especially for the physico-chemical parameters while the majority failed in the microbiological essay when stored at ambient temperature for the two-month investigation period.KEYWORDS: Coliforms, Conductivity, Microbiological Assay, Physical and Chemical Parameters,Turbidity, Sachet Wate

Agroclimatological Indices and Performance of Okra in Mixtures with Sorghum and Maize in Forest-Savanna Transition Zone of Nigeria.

Agroclimatological indices and performance of okra in mixtures with sorghum and maize in a Forest-Savanna transition zone of Nigeria was investigated at the Experimental Research Farmland of the National Horticultural Research Institutes (NIHORT), Ibadan during the 2009 and 2010 cropping seasons. Plants phenological stages formed the basic unit of time for the investigation. During these phenological stages, agroclimatological thermal and moisture indices were measured daily and processed into ten-day (decadal) averages likewise selected agronomic growth and yield parameters of the components crops were taken fortnightly. The results showed that the 2010 season crops had relatively longer growth duration, received more rainfall than 2009 season (692mm vs 487.2mm) while 2009 experienced warmer temperature during establishment and early vegetative stage than 2010 season (33.2°C vs 32°C), and (28.5°C vs 27 °C) during the reproductive phase for 2009 and 2010 season respectively. The mean pod yields of okra in both seasons were dependent on crop combination since pod yield in sorghum cultivars mixtures (Farin Dawa and Janare) (97.33 and 93.67 pods) was significantly higher than in maize mixtures (58.33 and 49.65 pods) in 2009 season likewise in 2010 season when okra pods in sorghum mixtures (Farin Dawa and Janare) had (309.67 and 232.33 pods) against (162.67 and 67 pods) in maize mixtures for the two sorghum cultivars. Result of correlation analysis showed that growing period rainfall contributes more to plant height and leaf area of the components crops than mean temperature. Key words: Phenological stages, agroclimatological indices, okra, sorghum, maiz