Global Journal of Environmental Sciences

Heavy metal profiles in various matrices of the Bonny/New Calabar River Estuary, Niger delta, Nigeria

2015-10-16T10:46:05+00:00

A study of the concentrations of Ca, Mg, K, Zn, Pb, Cd, Co, Cr, Cu, Fe, Ni and Na in the sediment, sea water, fish and crab of the Bonny/New Calabar River Estuary in Niger Delta, Nigeria was carried out using atomic absorption spectrophotometer A-100 for two consecutive years. The contamination levels of the respective metals varied between 2011 and 2012and the range of mean values for all metals in mg/kg were presented along with variations at statistically significant level (P <0.05) between the two years studied. Only K, Zn and Co exhibited variation in their concentrations in water samples between the two years at a statistical significant level (P <0.05) probability. In sediment, only Cr varied between the two years at a statistically significant level (P = 0.05). All metals concentrations were higher in sediment than in water samples.Bioaccumulation factor (BF) indicated a more potent source of metals from sediment than water with organisms accumulating Zn, Fe and Ni in the magnitude of 10, 6 and 5 times more from sediment than from water. Some metals were more accumulated in fish than crab and vice versa. The evidence of elevated levels of heavy metals in sediment and bioaccumulation in biota in the studied area may poise a wanton threat to the health of inhabitants whose diet is predominantly fish. This calls for regular monitoring to avert potential public health problems arising from consumption of metals in seafood.

Keywords: Heavy metals, Matrices, bioaccumulation, Bonny River, Niger Delta, Nigeria.

Phytoremediation of sewage sludge in soils contaminated with heavy metals

2015-10-16T10:46:05+00:00

The main source of heavy metals in most soils is sewage sludge. Naturally, the heavy metals in soils are transported to vegetations and cultivated crops. These pollutants need to be either reduced or eliminated in the soil to remediate the effects to man, animals, plants, soils, and groundwater. Hence, Jatropha curcas seedlings were planted on six different media to determine the concentration of heavy metals. Thereafter, it was discovered that Jatropha curcas plants through their roots, stems and leaves metabolism, morphology and mechanisms can reduce the concentration of heavy metals like Zinc, Lead, Chromium, Cadmium, and Copper etc effectively from any medium containing 100% sewage sludge. Thus, it was discovered that Jatropha curcas plant is suitable as a phytoremediator of heavy metals in soils.

KEYWORDS: Heavy metal, phytoremediation, sewage sludge, metabolism, morphology.

Diesel exposure of Tympanotonus fuscatus and its effects on enzyme activity

2015-10-16T10:46:05+00:00

The effect of mild concentrations of diesel (10.40,15.60,21.00 and 26.00 mg/l) on some biochemical parameters such as Aspartate transaminase (AST), Alanine transaminase (ALT), and Alkaline phosphatase (ALP), in the tissue of periwinkle (tympanotonus fuscatus) were examined using a renewal static bioassay for six days. The activities of the enzymes were measured on 120 specimens of periwinkle of size between 4.5-5.5cm lengths. The result of AST activity in the muscle showed either an increased or decreased activity against the control. The activity of ALT showed significant (p=0.05) decrease in all the test concentrations. ALT also showed significant difference (p=0.05) which were either higher or lower than the control value. In the viscera, activity of AST significantly increased
(p=0.05) than that of the control. ALT activity was significantly increased (p=0.05) above the control except at 10.40ml/L where a significant decrease (p=0.05) was observed. Significant increase (p=0.05) was observed in the activity of ALP above the control value except at 10.40ml/L. The result of the tissue enzyme activities indicated alteration in the biochemistry of tympanotonus fuscatus and therefore could be used as a biomarker of aquatic pollution and toxicities.

KEYWORDS: Diesel, Tympanotonus fuscatus, Enzyme, Toxicity, pollution

Tannery wastes water treatment using Moringa Stenopetala seed extract

2015-10-16T10:46:05+00:00

High amount of heavy metal ions like Cr in the environment has been harmful for animal and human health. Bioadsorption of Cr from tannery wastes would be an alternative method to the chemical treatment in tannery industries. Hence, in this study the efficiency of Moringa stenopetala seed extract to adsorption Cr from tannery waste water was investigated. The influence of solution pH, adsorbent concentration, initial concentration of Cr, contact time and temperature on the efficiency of Moringa stenopetala seed extract for the adsorption of Cr from tannery effluent was studied. Results obtained revealed that in strongly acidic condition Moringa stenopetala seed extract was less efficient to remove Cr. However, the result of the present study showed that Moringa stenopetala seed extract at a concentration of 1g/100 ml and pH of 9.5 decreased the concentration of Cr in tannery waste by 99.86%. In addition, the adsorption data was correlated using the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Among models studied Dubinin-Radushkevich isotherm was the best fit with correlation coefficient of 0.958. Moreover, thermodynamics parameters, such as Gibbs free energy (ÄGo), enthalpy (ÄHo), and entropy (ÄSo) were calculated. Results indicated that the bioadsorption of Cr by Moringa stenopetala seed extract was spontaneous, feasible and endothermic. The results of this study proved that Moringa stenopetala seed extract can be used to remove Cr from tannery effluent.

KEYWORDS: Moringa stenopetala, Cr, tannery, pH, temperature, concentration

Effect of Indomie industrial effluent discharge on fish fauna of New Calabar River, Port Harcourt

2015-10-16T10:46:05+00:00

The effect of Indomie industrial effluent discharge on the fish fauna of New Calabar River was investigated in order to ascertain the influence of BOD, COD, DO, TDS, TSS, pH, salinity, phosphate and temperature on the composition and distribution of fish fauna. The diversity of the fish fauna was found to be poor, only 12 fish species in 6 families were identified. The highest number (10) of fishes was recorded in station 4 while the least number (1) of fishes was observed in station 1. The fish families were: Cichlidae (38.89%), Clupidae (33.33%), Pomadasyidae (16.67%), Bagridae (11.11%) while Genidae and Muglidae had zero percentage of fishes in its abundant. The resident fish species (Ethmalosa fimbriata and Tilapia guinensis) were highly adapted to the changes in the study environment and this was dependent on their trophic relationship within the environment. These species had great affinity for indomie industrial waste, because they feed on waste remains, mud/sediment silts and annelids, juveniles of shrimps and crabs. The deterioration of water quality was evident by the high BOD (12.80mg/L), COD (130mg/L), TDS (37mg/L), TSS (62mg/L), pH (5.2), salinity (50.54mg/L), phosphate (0.14mg/L) and temperature (270C) as well as the low dissolved oxygen (2.8mg/L) values observed. It was recommended that a routine treatment of the effluent before discharge into the water should be carried out so to maintain safe levels of industrial effluent in the immediate and extended environment.

Keywords: Effluent, pollution, environment, fish and fauna.

Status evaluation of heavy metals in waste disposal sites of champion breweries and plasto crown company, Uyo, Akwa Ibom State, Nigeria

2015-10-16T10:46:05+00:00

Sludge and soil samples were collected through purposive sampling method within Champion Breweries and Plasto Crown Company waste disposal sites during wet and dry seasons for status evaluation of their heavy metals (Fe, Pb, Zn, Ni, Cr, Cd, Co and Hg) for comparison with the control site and the world threshold standards for tropical soils. The results showed that the sludge pH value of 7.89 during wet season signified alkaline medium (outside the natural range of acidic medium for soils in the Niger Delta region of Nigeria) which was attributed to the high calcium content of the brewery effluent. The 7.42 pH value during wet season for soil in the Plasto Crown Company waste disposal site indicated alkaline medium which was due to the remnants of the wastes which formed lime to neutralize the acidic medium of the soil while the electrical conductivity values (below 4 dSm-1) indicated the nonsalinity of the soils. More so, a two way analysis of variance (ANOVA) statistical method used to run the analysis revealed that the soil in terms of heavy metal concentrations did not exceed the world threshold standards.

Keywords: Soil, sludge, heavy metal concentrations, permissible standards.