|
Volume 6 Number 1 2012
CONTENTS AND ABSTRACTS
Neha Sharma, Gurjinder Singh Hundal, Indu Sharma, Renu Bhardwaj (India) Effect of 24-Epibrassinolide on Protein Content and Activities of Glutathione-S-Transferase and Polyphenol Oxidase in Raphanus sativus L. Plants under Cadmium and Mercury Metal Stress (pp 1-7)
Full Text [PDF]
ABSTRACT
Original Research Paper: Heavy metal toxicity results in oxidative stress in plants. Cadmium and mercury are non-essential elements for plants and are thus toxic even at low concentrations. Brassinosteroids, an important group of plant hormones have been reported to ameliorate abiotic stress in plants. The present study was undertaken to evaluate the role of 24-epibrassinolide in ameliorating the stress caused by Cd and Hg metals in raddish plants. The seeds of Raphanus sativus L. were soaked in 24-epibrassinolide (0, 10-7, 10-9, 10-11 M) and were sown in soil medium containing Cd and Hg (0, 0.5, 1.0, 1.5 mM). Oxidative stress caused by heavy metals was assessed by studying the protein content and activities of Glutathione-S-transferase (GST) and Polyphenol oxidase (PPO) enzyme activities in 60 and 90 days old raddish plants. Results revealed that presence of metals in the soil medium lead to decrease in protein content which was improved with the treatment of 24-epibrassinolide. The treatment of metals enhanced the antioxidative enzymes activities. These activities were further enhanced by 24-epibrassinolide treatments.
Akhil Pandey, Debdulal Banerjee (India) Biosorption of Cadmium (II) using Discarded Biomass of Aspergillus aculeatus DBF9 (pp 8-13)
Full Text [PDF]
ABSTRACT
Original Research Paper: The cadmium (Cd) biosorption potential of Aspergillus aculeatus DBF9 biomass was investigated. Among different forms of biomass, air-dried one was found most suitable in Cd removal. Maximum Cd (II) biosorption takes place at initial solution pH 4.5 after 90 min. Air-dried 150 mg of cell mass of A. aculeatus can remove about 78% of Cd (II) from 10 ml of 300 mg/L Cd (II) solution. The adsorption kinetics of Cd was modeled with a pseudo-second order equation to correlate the experimental data. The equilibrium data fitted very well to a Langmuir isotherm model more than to the Freundlich isotherm model. Metal accumulation was confirmed with FTIR, EDAX, and SEM analysis. This indicates that biosorption of Cd in A. aculeatus mainly occurs through ion exchange. Metal absorption properties of A. aculeatus can be used in Cd removal from industrial effluents.
Natarajan Hemalatha, Othumbam Kat Remadevi, Chandrasekaran Ramanigopal (India) Influence of Tannin in Soil Adjacent to Acacia nilotica (L.) Willd. ex Del. on Microbial Population (pp 14-20)
Full Text [PDF]
ABSTRACT
Original Research Paper: The tannin polyphenol in soil influence microbial growth. Soil fertility is mainly due to the microbial load existing in a place which is decided by the physical and chemical nature of the soil. Hence in the present study, we attempted to estimate the different microbial populations in a tannin-rich soil adjacent to Acacia nilotica (L.) Willd. ex Del. trees and compared the results with microbial populations present in an area where there was no tannin. The present study revealed shifts from normal counts of predominant soil microbial groups. In non-tannin soil, bacterial counts (720 CFU × 104/g) outnumbered fungal and actinomycete counts. Compared to other groups, fungi were the least abundant in non-tannin soils (5.8 CFU × 104/g). The sequence of dominance in tannin soil followed the order: fungi < actinomycetes < bacteria. A comparatively higher total microbial count was responsible for high aggregate stability and reduced bulk stability of non-tannin soil. Nitrifiers in tannin soil are inhibited by tannins to account for lower soil nitrate content (4 µg g-1 dry soil) compared to non tannin soil (33 µg g-1 dry soil). The ecological consequences of elevated tannin levels of 5% may include allelopathic responses, changes in soil quality and reduced ecosystem productivity.
Jude C. Igwe, Felix C. Nwadire, Augustine A. Abia (Nigeria) Kinetics and Equilibrium Isotherms of Pesticides Adsorption onto Boiler Fly Ash (pp 21-29)
Full Text [PDF]
ABSTRACT
Original Research Paper: The adsorption of two herbicides paraquat dichloride (N-N-dimethyl-4,4-bipyridinium dichloride) and glyphosate (isopropyl amine glycine) from aqueous solution onto activated boiler fly ash (BFA) was investigated. Kinetics and equilibrium adsorption was followed by UV-spectroscopy in a batch system and the data were treated according to various rate and isotherm models. The results show that the adsorption capacities is dependent on both concentration and time and the adsorption rate increases rapidly with each specified concentration at initial time of one to ten min and attains equilibrium at about 10 min. Glyphosate was adsorbed more than paraquat dichloride. The adsorption dynamics of the pesticides were well fitted to the pseudo-second order kinetic model, with coefficient of determination of 0.9900 for glyphosate and 0.9714 for paraquat dichloride. The equilibrium adsorption was modeled by five isotherms namely; Langmiur, Freundlich, Dubinin-Radushkevich, Temkin and Harkins-Jura. From the coefficient of determination (R2), the Freundlich isotherm gave a better fit for paraquat dichloride (0.9899) while the Harkins-Jura isotherm gave a better fit for glyphosate (0.9719). The apparent energy of sorption or mean biosorption energy was found to be 50.0 and 48.83 KJ/mol for glyphosate and paraquat dichloride, respectively, indicating chemisorptions mechanism. Also, a two way ANOVA without replication shows that the differences in the results of the fitness of the isotherms were not significant. Hence, the use of BFA an agricultural waste in the adsorption of these toxic pesticides from aqueous solution is feasible and could be developed into a cheap, cost effective energy requirement and affordable technology for pesticide clean up from wastewater.
Jude C. Igwe, Emmanuel O. Odo, Solomon E. Okereke (Nigeria), Edidiong E. Asuqou (UK), Innocent C. Nnorom, Obinna C. Okpareke (Nigeria) Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Some Fish Samples from Mushin Area of Lagos, Nigeria: Effects of Smoking (pp 30-35)
Full Text [PDF]
ABSTRACT
Original Research Paper: Five different fish samples (mackerel (Scomber scombrus), tilapia (Oreochromis niloticus), croaker (Micropogonias unduletus), herring (Clupea harengus), horse mackerel (Trachurus trachurus) and blue whitting (Micromesistus pontassou)), fresh and smoked, bought from Mushin market in Lagos State, Nigeria, were sampled for polycyclic aromatic hydrocarbon (PAH) contaminants. The levels of PAHs ranged from 0.004 μg/kg for acenaphthene in dry M. pontassou to 2.275 μg/kg for phenathrene in dry S. scombrus. Florene, phenathrene, anthracene and fluoranthene were detected in all the fish samples. Indeno (1,2,3) perylene, dibenzo(a, h)anthracene and benzo(g, h, i)perylene were not found in any of the fish samples. Smoking increased the levels of PAHs in the fish samples. These results show that PAH levels in the fish samples are higher than the permissible limit set by the World Health Organization (WHO) and the Agency for Toxic Substances and Disease Registry (ATSDR). The implications of these contaminants in the environment together with their associated health hazards are also examined.
Cyprian Y. Abasi, Augustine A. Abia, Jude C. Igwe (Nigeria) Sorption Kinetics and Intraparticle Diffusivities of Pb (II), Fe (III) and Cd (II) ions on Unmodified Raphia Palm Fruit (Raphia hookeri) Endocarp (pp 36-40)
Full Text [PDF]
ABSTRACT
Original Research Paper: Sorption kinetics of Pb (II), Fe (III) and Cd (II) ions from aqueous solution by unmodified raphia palm (Raphia hookeri) fruit endocarp was carried out through time dependent studies. The kinetic behaviour of the metal ions towards the adsorbent was studied with the pseudo-second order rate model. The rate constants (g/mg-min) were determined to be 7.02 × 10-3, 1.02 × 10-2 and 2.62 × 10-3 for Pb (II), Fe (III) and Cd (II) respectively. Sorption capacities based on the pseudo-second order model were found to be 196.08 mg/g, 169.5 mg/g and 188.68 mg/g for Pb (II), Fe (III) and Cd (II) respectively. Intraparticle diffusion models such as fractional attainment to equilibrium (FATE), McKay and Poots, Weber and Morris and Elovich equations were also used to investigate the predominant sorption mechanism. The poor fit of these intraparticle diffusion models as seen from their correlation coefficient values which ranged from 0.718 to 0.872 for Elovich equation, 0.730 to 0.837 for external film diffusion, 0.825 to 0.819 for particle diffusion, and 0.719 to 0.872 for percent adsorbed, showed that the sorption mechanism was not intraparticle diffusion controlled but film diffusion controlled.
Foluso O. Agunbiade, Bamidele I. Olu-Owolabi, Kayode O. Adebowale (Nigeria) Comparative Assessment of Coastal Water Usage Supports Using Water Quality Indices and Fuzzy Synthetic Evaluation Methods: A Case Study of Ondo State Estuary, Nigeria (pp 41-49)
Full Text [PDF]
ABSTRACT
Original Research Paper: The ability of water quality indices and fuzzy synthetic evaluation methods to combine large and technical water quality data into a single value that could help understand and communicate the status of water bodies and their usage supports for policy formulation is revealed by this study. Three water quality indices and two fuzzy synthetic evaluation methods were used to assess the usage support of Ondo estuarine water and the results compared. The indices revealed that the sites distant to the estuarine discharge point improved in quality and support uses than the ones nearer. Desalination of such will further improve is usage support. Anthropogenic activities are negatively affecting the quality of the environment and need to be managed if good quality water will be made available for economic uses and the vast aquatic life resources in the estuary and the neighbouring Atlantic Ocean will not be adversely affected.
Luke N. Ukiwe, Jude I. Alinnor, Chinonye I. Iwu (Nigeria) The Influence of Sludge Concentration and Sulphuric Acid on Bioleaching Efficiency of Thiobacillus thiooxidans on Sewage Sludge (pp 50-54)
Full Text [PDF]
ABSTRACT
Original Research Paper: Microbial leaching using Thiobacillus thiooxidans was investigated to solubilize heavy metals (HMs) from domestic sludge at different concentrations. Results obtained showed that 100% Cr was solubilized with 50 ml sludge when the bioleached sludge was digested with 50% (v/v) H2SO4, while 90% Cr was also solubilized with the same amount of sludge when the bioleached sludge could not be digested with H2SO4. However, 3.0% Cd was the metal least solubilized overall with 100 ml sludge when the bioleached sludge could not be digested with H2SO4. For high HM extraction efficiency, digestion using H2SO4 must be performed after bioleaching of sludge.
Luke N. Ukiwe, Gerald O. Onyedika, Vivien I. Uche, Chinonye I. Iwu (Nigeria) Physicochemical Water Quality Indicators of Groundwater in Ishiagu, Ebonyi State, Nigeria (pp 55-60)
Full Text [PDF]
ABSTRACT
Original Research Paper: Physicochemical properties of groundwater in Ishiagu, Ebonyi State, Nigeria were investigated. Results obtained from analysis performed on samples of groundwater collected from boreholes of six sample areas (Amata, Ihie, Amaokwe, Ihetutu, Amaeze, Ngwo-Ngwo) during the raining season of June, July and August, respectively, showed that chloride (Cl-) concentration ranged from 26.9-49.7 mg/l, while sulphate (SO42-) and phosphate (PO43-) concentration ranged from 27.8-92.1 mg/l and 0.32-1.02 mg/l respectively. However, trace amounts of the metals Fe, Zn, Pb and Cd ranged from 0.01-0.05 mg/l. These values as well as those of the anions (Cl-, SO42-, PO43-) were well below WHO permissible standards.
Adewuyi Gregory Olufemi, Etchie Ayotunde Titilayo, Etchie Ogbemi Tunde (Nigeria) Evaluation of Total Petroleum Hydrocarbons (TPH) and some related Heavy Metals in Soil and Groundwater of Ubeji Settlement, Warri Metropolis, Nigeria (pp 61-65)
Full Text [PDF]
ABSTRACT
Original Research Paper: Soil and groundwater samples in areas of oil spill in Ubeji settlement, Warri metropolis, Nigeria, were collected in order to determine the oil and grease, total petroleum hydrocarbons (TPH) and some related heavy metals in the samples. Control samples were taken from a low density residential area in Delta State (Ekrejeta in Abraka) which is relatively free from petroleum activities. The parameters were evaluated in order to determine the quality of the soil and groundwater of Ubeji settlement, as a follow up on an earlier research conducted on the surface water and sediment of the settlement’s river. This research is so important because the local population uses the soil and water resources for agricultural and domestic purposes. Measurements of oil and grease and TPH in samples were done gravi-metrically, while atomic absorption spectrophotometry was used for determination of heavy metals. For oil and grease and TPH, the soil had mean concentrations of 1064.90 ± 7.70 and 579.10 ± 9.30 mg kg-1, respectively, while groundwater had 315.15 ± 11.60 and 28.70 ± 1.30 mg L-1, respectively. Mean heavy metal concentration of the soil and groundwater varied between 0.30 ± 0.01 to 215.49 ± 25.33 mg kg-1 and 0.03 ± 0.01 to 3.05 ± 0.07 mg L-1, respectively. These values reveal that the investigated samples had higher levels of oil and grease, TPH and heavy metals than the control samples and regulatory standard limits. This however, is an indication of pollution of soil and groundwater of the settlement by petroleum hydrocarbons.
Maimuna Waziri, Abdulrahman A. Audu (Nigeria) Consequences of River Obstruction: High Incidence of Pollutants in Kumadugu-Yobe Basin of Nigeria (pp 66-70)
Full Text [PDF]
ABSTRACT
Research Note: The obstruction of the flow of Kumadugu-Yobe River in the north eastern region of Nigeria has affected the entire river system. This study was undertaken to determine the levels of metal pollutants and organic pollution indicators in the water body in order to assess the impact of the obstruction and possible environmental threats posed by pollutants. Water and sediment samples were collected from five selected locations which consisted of three sampling sites each and subjected to standard analytical tests to determine the levels of Fe, Cu, Zn, Co, Cr, Ni and Pb as well as the DO, BOD, COD and TOC of the water body. Results showed some level of pollution by organic pollutants and heavy metals when compared with WHO and NAFDAC specifications for drinking water and aquatic ecosystems. The correlation coefficient (r) values of the organic pollution indicators with the metals revealed positive correlations. The obstruction of the natural flow of water into the river also resulted in the invasion and spread of aquatic weeds into the surroundings. It is postulated that the pollution in the river came from upstream as well as washings from the surrounding lands due to flooding at the peak of the rains during the months of August to September. It is recommended that the management of the Kumadugu-Yobe basin should take proper steps to constantly monitor the flow of metal and organic pollutants in to the river.
|
