Assessment of Heavy Metals Pollution in Dumpsites in Ilorin Metropolis

Speciation and distribution of heavy metals in soil controls the degree to which metals and their compounds are mobile, extractable, and plant available. Eight strategically located dumpsites in Ilorin metropolis (an averagely growing city and a state capital) were chosen for dumpsites-soil characteristics study. Both the estimated total and potentially available metals were studied using EPA 1311 and Tessier’s et al methods respectively. It wasobserved that the groundwater is vulnerable to contamination as no treated basement to adsorb toxic metals was provided for in the sites. About 70% of Mn, Fe, Zn, Cd and Pb were found in the exchangeable bound to carbonate and bound to iron/manganese oxide fractions. These fractions represent the mobile and lethal portion of the total metals to the ecosystem. The metal enrichment factor revealed that Zn, Cd and Pb were of anthropogenic source while Fe is of natural and anthropogenic sources. The dumpsites in Ilorin, therefore pose negative consequences on the soil and groundwater environmen

The influence of ph and adsorbent concentration on adsorption of lead and zinc on a natural goethite

Adsorption characteristics of Pb and Cd were conducted on a natural goethite from Kaduna (Niperia) and compared same with a synthetic goethite. The adsorption data was fitted into Langmuir model which gave Langmuir constants k and Xm for Pb and Cd as 4.99 & 2.40 and1.43 & 1.05 respectively. The adsorption behavior was essentially the same, although, synthetic goethite sorbed a little more metal ion than the natural goethite. This was attributed to the higher proportion of goethite in synthetic than natural goethite per unit mass of sample rather than greater chemical reactivity of the synthetic goethite. The influence of variable pH and adsorbent concentrations on the sorption of Pb and Cd by the natural goethite was studied. Sorption efficiencywas greatly governed by pH with nearly 100% adsorption of Pb occurring at initial pH of 5. Generally, Pb was sorbed more strongly with increasing pH from 3 to 5 than Cd and thus poses less environmental threat. Efficient removal of Pb was achieved at lower dose of goethite, as there was no appreciable increase in the amount of Pb adsorbed when the adsorbent dose was increased

The Impact of a River on the Water Quality of Nearby Wells: A Case Study of Aluko River, Ilorin, Nigeria

Hand dug wells were sampled in 5 selected areas in the vicinity of River Aluko course, Ilorin. The ranges of the average value of the parameters studied are: 6.8-8.3 for pH; 325-524 mg/l for total hardness (TH); 0.039-0.69 for organic carbon content; 29-30 OC for temperature; 0.683-0.863 mg/l for total dissolved solids (TDS); 0.014- 0.068 mg/l for total suspended solids (TSS); 0.701-0.914 mg/l for total solids (TS); 6.60-21.50 mg/l for total alkalinity; 0.73-1.90 mg/l for chloride; 0.129-0.273 mg/l for nitrate; and 0.008-0.243 mg/l for sulphate. All the trace metals except Fe and K were within the WHO standard for drinking water. The % bioavialable metals (F1 + F2 + F3) for Fe, Mn, Ni, Zn, Co, Cd and Cu ranges between 87.1 and 95.4, 20.7 and 78.4, 39.3 and 68.7, 42.5 and 65.8, 64.0 and 86.6 and 92.9, 88.2 and 92.9, 40.00 and 60.10 respectively. The proportion of the mean metals concentrations of the bioavailable metals follows the order Fe > Cd > Co > Ni > Zn > Cu > Mn and the % bioavailable metal for the five locations is in the order: Ikokoro > Baboko > Ita-Amodu > Opomolu > Edun. The assessment of the well sediment using enrichment factor, EF, and geoaccumulation index revealed that Co and Cd from all the sampling points were evidenced as having more enrichment and mostly due to anthropogenic sources; whereas, Mn, Ni, and Zn were enriched from natural sources.Keywords: Bioavailability, Geochemical indices, Sequential extraction, Well-wate

Characterization of Synthesized Goethite and Natural Goethite sourced from Itakpe in North Central, Nigeria

This study was aimed at characterizing samples of natural and synthetic goethite (α-FeOOH) in order to establish their composition and properties. The natural goethite (NGT) sample was obtained from Itakpe area in North Central, Nigeria while the synthetic goethite (SGT) fine particles were synthesized by the air oxidation method. Techniques employed in the investigation included determination of point of zero charge (pHpzc), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), Brauner-Emmet-Teller Isotherm (BET) and particle nano-sizer. Results of the study showed that pHpzc of the NGT and SGT were 7.0 and 8.0 respectively. The main surface functional group from FTIR in both samples was the OH while the XRF studies indicated a high content of iron (66.193 % in NGT and 66.4009% in SGT). The SEM analysis revealed a high porosity being associated with SGT than the natural sample. Furthermore, The surface area of SGT as obtained from BET analysis was 797.662 m2/g while the nano-sizer also revealed a near nano-size for the synthesized goethite with particle size of about 172-173 nm. In view of the results of this study, SGT could relatively be used as a more effective adsorbent. It is also believed that both samples will find applications in lots of other analytical processes.Keywords: Adsorption, BET, Natural goethite, Particle nano-sizer, Synthetic goethit

REMOVAL OF CADMIUM FROM AQUEOUS SOLUTION USING MANGANESE HEXACYANOFERRATES (II)/(III)

A series of solid insoluble mixed potassium manganese hexacynoferrates (II) and (III) of the general formula KyMnxFeII/III(CN)6.zH2O were prepared by classical precipitation and local growth methods. All synthesized products were thermally stable up to 300 oC and were highly insoluble in most mineral acids except hot perchloric acid. The sorption of cadmium ion from 0.1 M HNO3 solutions on manganese hexacyanoferrates (II) and (III) was investigated. Both sorption kinetics and isotherms were studied. The sorption kinetics for cadmium uptake was observed to follow two steps with fast kinetics in the first step within 5 min. The manganese hexacyanoferrate(III) was found to exhibit higher sorption capacities than manganese hexacynoferrates(II). The highest sorption capacity was achieved with manganese hexacyanoferrate(III) prepared by local growth method. The uptake of cadmium from aqueous solution appeared to follow adsorption mechanism and not ion exchange as characteristic of many other divalent hexacyanoferrates. The sorption data were fitted with Langmuir adsorption isotherm. KEY WORDS: Cadmium removal, Potassium manganese hexacynoferrates(II)/(III) Bull. Chem. Soc. Ethiop. 2007, 21(2), 221-228

Comparative Dissolution of Natural Goethite Samples in HCl and HNO3

The dissolution of goethite samples in mineral acids from to extreme parts of Nigeria (Osogbo and Kaduna) have been investigated. The rate of dissolution was found to be slightly faster in HCl than HNO3. The higher rate of dissolution in HCl could be attributed to the complexing ability of Cl- in addition to the H+ effect while lowering effect by NO3- was attributed to adsorption of NO3 on to the goethite surface. Mononuclear complexes, especially bidentate of oxyanion are found to accelerate dissolution as opposed to binuclear complexes. A binuclear bidentate surface complex formation between NO3- and Fe3+ was therefore proposed to account for the inhibition observed. The possible formation of Fe\u2014Cl reduces both the surface positive charge and the repulsion between the oxide surface and protons in solution. This produced accelerated proton dissolution. The effect of temperature on the initial dissolution rate fit into Arrhenius equation, with Kaduna goethite exhibiting higher rate than Osogbo type in both acids. The activation energies for Kaduna goethite sample are 66.11 and 82.43 kJmol-1 in 0.1M HCl and 0.1M HNO3 respectively while for Osogbo goethite sample are 54.60 and 76.32 kJmol-1 in 0.1M HCl and 0.1M HNO3 respectively. The frequency factors of 8.4 x 10-4 & 11.17 x10-4 and 5.0 x 10-5 and 3.09 x 10-3 for Kaduna and Osogbo goethite samples were obtained. @JASE

Adsorption of Congo Red Dye from Aqueous Solution using ZnO and Al2O3/ZnO Composite: Isotherm, Kinetic and Thermodynamic Data

Herein, an adsorption study of congo red (CR) dye onto ZnO and Al2O3/ZnO  is reported. ZnO was prepared using conventional chemicals by co-precipitation method and Al2O3 used in the composite was prepared through recycling of aluminium waste. Information about the materials was obtained through spectroscopic techniques. A batch adsorption method was used to obtain the adsorption data from which isotherm, kinetic and thermodynamic parameters were obtained. The result of the adsorbents characterisation revealed the expected properties of the prepared materials. The adsorption capacities at 250 mg/L of CR dye were 24.33 mg/g and 24.57 mg/g for ZnO and Al2O3/ZnO respectively. The isotherm study of the adsorption process revealed that Langmuir model fitted best the adsorption data with monolayer adsorption capacities (qm) of 27.67 mg/g and 33.39 mg/g for ZnO and Al2O3/ZnO respectively. The adsorption was rapid within the first 15 min and the equilibrium was reached at 45 min. The kinetic study followed a pseudo-second-order model with the rate constant of 0.049 and 0.093 g.mg-1.min-1 for ZnO and Al2O3/ZnO  respectively. Experimentally, the process was endothermic and was supported by the positive values of enthalpy (ΔH) with positive values of entropy (ΔS). The change in free energy (ΔG) is negative at all temperatures studied, indicating spontaneity but more spontaneous for Al2O3/ZnO than ZnO. The adsorption of CR dye from an aqueous solution onto ZnO as an adsorbent can be slightly improved upon by the introduction of Al2O3 to form Al2O3/ZnO composite

Clinical characteristics, etiology and antimicrobial susceptibility among overweight and obese individuals with diarrhea: observed at a large diarrheal disease hospital, Bangladesh

Background:The present study aimed to determine the clinical characteristics and etiology of overweight and obese (OO) individuals with diarrhea attending an urban Dhaka Hospital, International Centre for Diarrheal Disease Research (icddr,b), Bangladesh.Methods:Total of 508 under-5 children, 96 individuals of 5-19 years and 1331 of >19 years were identified as OO from the Diarrheal Disease Surveillance System (DDSS) between 1993-2011. Two comparison groups such as well-nourished and malnourished individuals from respective age stratums were selected.Results:Isolation rate of rotavirus was higher among OO under-5 children compared to malnourished group (46% vs. 28%). Rotavirus infection among OO individuals aged 5-19 years (9% vs. 3%) (9% vs. 3%) and >19 years (6% vs. 4%) (6% vs. 3%) was higher compared to well-nourished and malnourished children. Conversely, Vibrio cholerae was lower among all OO age groups compared to well-nourished and malnourished ones. Shigella (4% vs. 6%) (4% vs. 8%), and Campylobacter (3% vs. 5%) (3% vs. 5%) were lower only among OO in >19 years individuals compared to their counterparts of the same age stratum. Salmonella was similarly isolated in all age strata and nutritional groups. In multinomial logistic regression among under-5 children, significant association was observed only with use of antimicrobials at home [OR-1.97] and duration of hospital stay [OR-0.68]. For individuals aged 5-19 years, use of antimicrobials at home (OR-1.83), some or severe dehydration (OR-3.12), having received intravenous saline (OR-0.46) and rotavirus diarrhea (OR-2.96) were found to be associated with OO respectively. Moreover, significant associations were also found for duration of diarrhea before coming to hospital (>24 hours) (OR-1.24), Shigella (OR-0.46), and Campylobacter (OR-0.58) among >19 years OO individuals along with other associated co-variates in 5-19 years group (all