Environmental Studies of Thermal Power Station Effluents: (A Case Study of Egbin Thermal Station, Ikorodu).

This research work was carried out to investigate the level of pollution from the Egbin thermal station and their significant effects on the environment. Samples were collected in duplicate at four different locations. The major parameters investigated on analysis include heavy metals, anions and physico-chemical parameters. BUCK 210 VGP flame atomic absorption spectrophotometer (AAS) model was used for the metal analysis. Iron, zinc and copper are the predominant metals in the samples while chromium was not detected at some of the sampled locations. The average concentrations of zinc, iron, copper and chromium were 0.153 mg/L, 3.635 mg/L, 0.088 mg/L and 0.080 mg/L respectively. The effluents average for temperature, pH, and conductivity were 34oC, 6.98, 445 S/cm respectively. Hardness, TS, TDS, SS, Alkalinity, acidity, DO, BOD5, phosphate, chloride and sulphate concentrations were 47.5 mg/L, 98.75 mg/L, 68.5 mg/L, 30.25 mg/L, 31.90 mg/L. 6.44 mg/L. 5.76 mg/L, 9.61 mg/L, 0.18 mg/L, 40.37 mg/L and 67.41 mg/L respectively. The high concentration of iron, zinc and some of the physicochemical parameters determined in the samples from the Egbin treatment plant and from the point of discharge showed that the effluents from the Egbin thermal station contribute to the pollutants load in the receiving lagoon.Key Words: Effluents, Metals; AAS, Pollutants, Thermal statio

Evaluation of Heavy and Trace Metals in Fingernails of Young School Children and Adults in Ilorin, Kwara State, Nigeria

Fingernail samples of young school children and selected adults were collected with respect to sex and ages in Ilorin Kwara state. The aim of this study was to determine the level of heavy metals (Fe and Cu) and trace elements (Mg and K) in the fingernails of young school children and some selected adults using atomic  absorption spectrophotometer techniques for metal analysis. Soil samples were collected from the automobile workshop of the adults examined. Sample collection and preparation were carried out using standard  procedures. The result of the study showed presences of heavy metal in the fingernails of young school childrenand Adults in order of Fe >Cu (0.43-6.85 μg/g, Cu 0.01-0.08 μg/g) and for essential trace metals Mg > K (Mg 0.47-1.97 μg/g, K 0.25-1.32 μg/g) respectively From the result of the study, Fe show higher concentration while Cu shows the least level. Metal concentration is higher in young school children when compared with Adults, statistical analysis show that there was significant difference between the concentrations of heavy metal in fingernails of young school children when compared with Adults. For soil samples analyzed at the automobile workshop, the concentrations of heavy metals range between Fe (344.97μg/g); Zn (2.4442 μg/g); Pb (0.93667μg/g), Cr (0.535 μg/g) and Cu (0.5017μg/g) respectively.KEYWORDS: Heavy metals, fingernails, children and adults, AA

The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in virulence of a gene with a yet unknown function, st313-td, detected in ST313 through comparative genomics. Additionally, the structure of the genomic island ST313-GI, harbouring the gene was determined. The gene st313-td was cloned into wild type S. Typhimurium 4/74 (4/74-C) as well as knocked out in S. Typhimurium ST313 02-03/002 (Δst313-td) followed by complementation (02-03/002-C). Δst313-td was less virulent in mice following i.p. challenge than the wild type and this phenotype could be partly complemented in trans, indicating that st313-td plays a role during systemic infection. The gene st313-td was shown not to affect invasion of cultured epithelial cells, while the absence of the gene significantly affects uptake and intracellular survival within macrophages. The gene st313-td was proven to be strongly associated to invasiveness, harboured by 92.5% of S. Typhimurium blood isolates (n = 82) and 100% of S. Dublin strains (n = 50) analysed. On the contrary, S. Typhimurium isolates of animal and food origin (n = 82) did not carry st313-td. Six human, non-blood isolates of S. Typhimurium from Belarus, China and Nepal harboured the gene and belonged to sequence types ST398 and ST19. Our data showed a global presence of the st313-td gene and in other sequence types than ST313. The gene st313-td was shown to be expressed during logarithmic phase of growth in 14 selected Salmonella strains carrying the gene. This study reveals that st313-td plays a role in S. Typhimurium ST313 pathogenesis and adds another chapter to understanding of the virulence of S. Typhimurium and in particular of the emerging sequence type ST313

Investigation of corrosion effect of mild steel on orange juice

This paper aims to investigate the corrosion effect of mild steel in orange juice using a weight loss technique. Test specimens with known weights were immersed in the test media (orange juice with preservatives, natural orange juice and water) for a total exposure time of 10 days. Weight loss was measured at two day intervals for the determination of corrosion rate effect. Corrosion aggressive substance was discovered to have significant impact on the degradation of equipment and the maintenance or replacement of products lost or contaminated as a result of corrosion reactions. Results revealed that the corrosiveness of sweet orange juice on mild steel was mainly a function of its acidity. Packed orange juice with preservative was most corrosive followed by natural orange juice and water, respectively.Management of Cape Peninsular University of Technolog

Investigation of corrosion effect of mild steel on orange juice

This paper aims to investigate the corrosion effect of mild steel in orange juice using a weight loss technique. Test specimens with known weights were immersed in the test media (orange juice with preservatives, natural orange juice and water) for a total exposure time of 10 days. Weight loss was measured at two day intervals for the determination of corrosion rate effect. Corrosion aggressive substance was discovered to have significant impact on the degradation of equipment and the maintenance or replacement of products lost or contaminated as a result of corrosion reactions. Results revealed that the corrosiveness of sweet orange juice on mild steel was mainly a function of its acidity. Packed orange juice with preservative was most corrosive followed by natural orange juice and water, respectively.Key words: Corrosion, mild steel, weight loss, orange juice, acidity

Spectrophotometric determination of iron (III) in tap water using 8-hydoxyquinoline as a chromogenic reagent

A simple, rapid and sensitive spectrophotometric method was developed for the determinationation of trace amounts of iron (III) using 8-hydroxyquinoline as a chromogenic reagent. The proposed method was based on the reaction of iron (III) with 8-hydroxyquinoline in chloroform solution to form a metaloxine complex having a maximum absorption at 359 nm. Beers law was obeyed in the range of 1 to 14 ug/ml Fe3+. The recovery was between 98.60 and 103.30% with a coefficient of variation of 1.209%. The method was successfully applied to tap water samples and comparison with standard method showed the new method to be accurate and precise as the more sophisticated AAS commonly used for Fe determination

Sources environmental levels and toxicity of organotin in marine environment: a review.

Organotin compounds are highly versatile group of organometallic chemicals used in industrial and agricultural applications. The growing use of organotin containing compounds such as agricultural pesticides contaminates the aquatic environment by leaching and runoff. The presence of organotin compounds in environmental samples suggest to the vast increase in the use of organotin made products which affects all facets of the ecosystems and thus lead to the global ban on its application. A lot of work has been done on the presence of organotin compounds in environmental samples. The sources, human health risk and speciation of organotin compounds are discussed in this paper. The use of organotin compounds as biocides in antifouling paints has been the major believe for the sources but a large diversity of this compound can be detected in various environmental samples. The uses of organotin compounds as fungicide, glass coating, catalyst, PVC thermo stabilizer are the important sources of these contaminants. The accumulation of organotin compounds in the sea sediment or marine organisms such as fish, shells and squids are the possible ways of exposure to human, if it is consumed. The predominance of parent compounds (tributyltin and triphenyltin) is commonly found and this may indicate their slow degradation in sediment, biota and sea water samples and when recent inputs occur. The detection level of organotin compounds such as methyl butyltin, dibutyltin, tributyltin and triphenyltin are low in developed countries because organotin health risks are under control unlike the developing countries where their use is not controlled. Thus, there is need to monitor organotin contamination from large shipping vessels