Michael Horsfall - Academia.edu (original) (raw)
Papers by Michael Horsfall
The ability of NaOH-activated carbon derived from cassava peels waste to remove MY from aqueous s... more The ability of NaOH-activated carbon derived from cassava peels waste to remove MY from aqueous solution was carried out in a fixed-bed column adsorber. The parameters studied included initial solution concentration, Co, carbon bed height and volume flow rate. The temperature of operation and initial solution pH were 29 °C and 5.32 respectively. The optimum adsorption capacity, qe 4.12 mg/g was obtained at Co 10mg/L, bed height 10cm and flow rate, 13.3ml/min. Experimental data were analyzed with Langmuir, Freundlich and Temkin isotherm, as well as the Thomas, YoonNelson and Clark kinetic models. All the models were good fits for experimental data based on correlation coefficient, R 2 values. The ΔGads and Freundlich n (1.587) show that the biosorption was spontaneous, good and physical. Results show that NaOH-activated carbon from cassava peels has low capacity in the removing MY from aqueous solution.
Sorption of Manganese (II) and Chromium (III) Ions from Aqueous Solution Using Water Hyacinth Biomass (Eichhornia crassipes)
Journal of environmental science & engineering, Nov 30, 2010
The use of water hyacinth biomass as adsorbent for Cr(superscript 3+) and Mn(superscript 2+) ions... more The use of water hyacinth biomass as adsorbent for Cr(superscript 3+) and Mn(superscript 2+) ions from aqueous solution by means of batch-adsorption technique was investigated to determine the potential ability of the biomaterial for metal ion removal. The equilibrium isotherm study showed that the maximum monolayer coverage on the biomass surface was 0.933 mg•g^(-1) and 0.874 mg•g^(-1) for Mn(superscript 2+) and Cr(superscript 3+) ions respectively. The highest percentage of Cr(superscript 3+) and Mn(superscript 2+) ions adsorbed by the biomass was 86.4% and 82.6% at the optimum pH of 4.0 and 6.0 respectively. The results also showed that the highest percentage removal 82.5% and 78.3% was obtained at 30 and 20 minutes respectively for Cr(superscript 3+) and Mn(superscript 2+) ions. The sorption process was examined by means of the Langmuir model. The adsorption equilibrium data were found to follow the Langmuir isotherm model with high coefficients of determination (R^2=0.990 and 0.999) for Cr(superscript +) and Mn(superscript 2+) ions respectively. The adsorption capacity of water hyacinth showed that water hyacinth will be useful in recovering chromium (Ⅲ) and manganese (Ⅱ) ions from solution and their subsequent removal from industrial effluents.
Preparation and characterization of activated carbon from water hyacinth (Eichornia Crassipes) and water spinach (Ipomoea Aquatica)
Scientia Africana, 2011
Analysis of arsenic in oysters using reversed phase HPLC-ICPMS/ ESI-Orbitrap-MS
Ife Journal of Science, 2016
Total metal concentrations and five-stage sequential extraction schemes were employed to investig... more Total metal concentrations and five-stage sequential extraction schemes were employed to investigate the potential environmental risk of six important metals in sediments from the upper reaches of Imo River system in Southeastern Nigeria. The concentrations of trace metals in each fraction were determined using AANALYST 400 Perkin-Elmer AAS. The average concentrations (mg/kg) for the six metals in dry season sediment samples were 0.30 ± 0.09 (Cd), 2.28 ± 1.20 (Cu), 12.35 ±8.97 (Zn), 1.79 ± 0.74 (Ni), 3.52 ± 1.68 (Pb), and 2025.72 ± 304.43 (Fe), while the mean metal concentrations (mg/kg) in wet season samples were 0.29 ± 0.05 (Cd), 2.06 ± 0.74 (Zn), 24.57 ± 5.78 (Cu), 5.79 ±1.67 (Ni), 6.26 ± 3.73 (Pb), and 2534 ± 476.98 (Fe) respectively. Fe and Pb content in river sediments exceed the Federal Environmental Protection Agency (FEPA) regulatory Standards for soil. Chemical speciation study applying the five-stage sequential extraction schemes revealed that Cd in sediment prevails most...
Journal of Drug Design and Medicinal Chemistry, 2019
The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oi... more The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oil-producing communities (Oboburu, Obagi, and Ogbogu) in Egi, Niger Delta were assessed for variability, origin and health risks. The result showed that tPAHs of Oboburu were 1344±1685 mg/kg for carcinogenic while BaP (257.3±270.5 mg/kg) had the greatest value. Obagi had 4154±3461 mg/kg for cPAHs with BkF (861.5±543.7 mg/kg) having the greatest amount. Ogbogu was 354.7±360.7 mg/kg for total cPAHs while BgP (104.1±141.8 mg/kg) had highest amount. The dominant PAHs were BbF, BkF, DbA, BaP, IdP and BgP. The principal component analysis (PCA) indicated that the PAHs were majorly of pyrogenic and petrogenic origin. The predicted risk due to PAHs in soil for children showed tPAHs was 1.68E-2, with high risk for BaP (9.05E-3), IdP (5.05E-3), BbF (1.63E-3) and BkF (1.04E-3), while the adults estimation showed tPAHs was 1.13E-2 and high risk were for BaP (2.30E-3), IdP (1.08E-3) and BkF (2.57E-4). These values are more than the limit of the US EPA risk management criterion (10-6 to 10-4) where management decisions should be considered. The trend indicated that their presence in the environment makes it unsafe for the dwellers.
Science Journal of Analytical Chemistry, 2019
The study was to identify the source and evaluate the health risk of heavy metals in contaminated... more The study was to identify the source and evaluate the health risk of heavy metals in contaminated agricultural soil from Egi community (Oboburu, Obagi and Ogbogu), Niger Delta, Nigeria. Multivariate and health risk equations were employed to achieve this. The mean of heavy metals in samples of Oboburu indicated high levels for Fe (271.0±156.6 mg/kg), Pb (111.2±94.97 mg/kg), and Mn (27.92±23.80 mg/kg), Obagi was high for Fe (248.4±175.9 mg/kg), Mn (80.46±12.40 mg/kg), and Co (116.3±193.7 mg/kg), and Ogbogu was high for Fe (160.9±150.3 mg/kg), Co (240.1±412.1 mg/kg), and Mn (42.90±16.82 mg/kg) respectively. Geo-accumulation index indicated that Pb, Cd and Co was of high contamination and the enrichment factor showed that metals were of anthropogenic sources. The Principle component analysis revealed three (3) components accounting for 88.448%, which revealed that the contamination in the sample was more of anthropogenic than biogenic. The Cancer Risk estimate for children population was of high risk for Ni, Cr, Cd and Pb (10-5 to 10-6) while adult population was 10-6 and lower. The non-carcinogenic risk indicated highest value for children in Co (2.75), Pb (1.70E-1) and Fe (1.32E-1), while adult in Co (1.007) and Fe (3.29E-2). The findings suggest human activities have contributed greatly to the contamination of the agricultural soil and usage of such may be of risk to the users.
![Research paper thumbnail of Chemical Speciation of some Heavy Metals in Sand Filter Media [SFM] Waste Dumpsite in Yenagoa, Nigeria](https://attachments.academia-assets.com/114155169/thumbnails/1.jpg)
](Journal of Applied Sciences and Environmental Management, 2020
The chemical speciation of five heavy metals [HMs] in spent sand-filter-media [SFM] waste dumpsit... more The chemical speciation of five heavy metals [HMs] in spent sand-filter-media [SFM] waste dumpsite was investigated with a view to ascertain their distribution and chemical availability of the heavy metals in the dumpsite. Samples were collected at the surface, 100cm depth of the dumpsite and 100m away from the dumpsite and analysed using FAAS for total concentration of Cr, Fe, Mn. Ni and Pb. Speciation analysis was carried out usingmodified Tessier’s sequential extraction method. The percentage concentrations showed that Pb occurred more at the exchangeable fraction with 90.6% at the top, 91.34% at 100cm depth. This signifies that Pb is biochemically available for in-take by living organisms. Fe had the highest concentration by mass 12mg/g but its occurrence of between 22- 28% is in the residual/inert fraction. Ni had 40% in the exchangeable and carbonate fractions at the surface and at 100cm depth. Cr had highest exchangeable fraction of 46.29% and 45.59% at the surface and 100cm...
International Research Journal of Pure and Applied Chemistry, 2019
The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution ha... more The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Theref...
Journal of Applied Sciences and Environmental Management, 2019
This study assessed the physicochemical characteristics and toxicity of water-accommodated fracti... more This study assessed the physicochemical characteristics and toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of Bonny Light Crude oil and Dispersit SPC 1000 (dispersant) to Mudskipper fish (Periophthalmus Papilio). There were variations in the levels of the physicochemical parameters. The coefficient of variation (CV) indicated that the temperature show the least variation of 2.24% and salinity the highest 98.12%.Hypothesis test for significant differences at p < 0.05 significance level however, showed that there were no significant differences in the levels of the measured parameters over the 96 hours. All the mudskippers fish samples exposed to the water accumulated water fraction of 10% bonny oil survived beyond 96 hours. An increase in toxicity of the oil was observed after 72-96 hour exposures of the mudskipper to the oil and dispersant CEWAF. For dispersant concentrations of 540 ml/L and 630 ml/L the survival of mudskippers was 80%. These mortalities might be due to the toxic effect of the dispersant, Dispersit SPC 1000.The Total Petroleum Hydrocarbon (TPH) and the Polycyclic Aromatic Hydrocarbon (PAH) in the test media were respectively 7.66-63.18 ppm and 0.82-5.26 ppm.10% Bonny light crude oil WAF had no effects on mudskipper survival. Exposures to 540 ml/L and 630 ml/L Dispersit SPC 1000 dispersed oil WAF (CEWAF) resulted in 20 % mortality. The lethal dose concentration was 885.5 ml/L (88.55%). The lowest observed effect concentration (LOEC) was found to be 540 ml/L.
Journal of Applied Sciences and Environmental Management, 2019
Marine oil spillage accidents greatly impact major risks to the environment in terms of the acute... more Marine oil spillage accidents greatly impact major risks to the environment in terms of the acute and chronic adverse effects not only to the offshore, but also the coastal ecosystem. This study assessed single and joint toxicological effect of Dispersit SPC 1000 and Bonny Oil on mudskipper fish (Periophthalmus papilio) from the brackish water research station of African Regional Aquaculture Centre, Buguma, Rivers State, Nigeria. The physicochemical parameters observed throughout the study were the pH, alkalinity and salinity were 6.83 ± 0.1, 40 mg/L± 0.2 and 17,655 mg/L respectively. The temperature and Dissolved oxygen (D.O.) and specific gravity averaged 26.7 o C ± 0.1, 5.70 mg/L ± 0.02 and 1.008 ± 0.001, respectively. Dispersit SPC 1000 was found to be toxic to the mudskipper at various % (v/v) concentration, above 60 % (v/v) concentration no fish survived after one hour. The relation between the probit mortality and log concentration showed a strong positive correlation between the dispersant concentration and fish mortality within 3 hours, with r 2 = 0.813 p = 0.05;The lethal dose Lc50 was 73.48%. Within 6 hours, the mortality increased as the dispersant exposure concentration was increased (r 2 = 0.872, p =0.05). The results of exposure of the mudskippers to the water-oil-dispersant mix (CEWAF) showed lower mortalities. Mortality was observed after 72 hours for dispersant concentration above 54 %. 63% dispersant concentrations, 20% mortalities was observed between 72 and 96 hours. Dispersit SPC 1000 alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant. There was no joint increase in toxicity between bonny oil and the chemical dispersant, as the mixing of the dispersant by the oil resulted in diminished toxicity of CEWAF and lower mortality.
International Journal of Biological and Chemical Sciences, 2010
Batch adsorption experiments were performed to study the removal kinetics of Basic Blue-9 dye fro... more Batch adsorption experiments were performed to study the removal kinetics of Basic Blue-9 dye from aqueous solution using activated carbon produced from water spinach. The percent removal of dye increased with time and attained equilibrium in 3 hrs and 20 mins for an initial dye concentration of 250 mg/l. Optimum removal of 96% dye was achieved at the equilibrium time of 200 mins. The equilibrium sorption capacity (q e1) obtained from the pseudo-first order linear plot was 2.75 mg/g with a rate constant, K 1 of 0.0115 g/ (mg/min. The experimental data was most suitably analyzed by the pseudo-second order model with a regression coefficient (R 2) value of 0.9949. The initial sorption rate, h o was found to be 0.095 mg/g min with an equilibrium sorption capacity (q e2) of 4.80 mg/g. The correlation coefficients R 2 1 and R 2 2 , for the first-and second-order equations were all high (>0.97), suggesting the suitability of both models for the experimental data.
Differential sorption behaviour of pure and acid treated pumpkin waste biomass on the sorption of... more Differential sorption behaviour of pure and acid treated pumpkin waste biomass on the sorption of Ni 2+ ion from aqueous solution was assessed by an ensemble of sorption techniques. Biomass was chemically treated by 0.50 N and 1.00 N 2-mercaptoethanoic acid solutions. Sorption capacity calculations from Langmuir isotherm model reveals the following amounts of Ni 2+ ions bound per gram of biomass: pure, 12.69; 0.5 N acid treated, 40.0; and 1.0 N acid treated, 42.19 mg/g. The sorption probabilities for Ni 2+ onto pure and differentially acid treated biomass were 0.19, 0.22 and 0.31 respectively. Acid treatment significantly enhanced the adsorption potential, adsorption density and sorption probability of biomass towards the metal ion. The negative values of E a suggest that sorption process is exothermic. This study demonstrates that fluted pumpkin waste could be utilized as low cost, environment friendly biosorbent for the removal of Ni 2+ and other trace metals from aqueous solution.
International Letters of Chemistry, Physics and Astronomy, 2014
Five composite samples of waste water were collected from waste water tank of a vegetable oil ref... more Five composite samples of waste water were collected from waste water tank of a vegetable oil refining company and were analyzed for physiochemical characteristics, heavy metal and organic pollutants. Physicochemical determinations were done according to standard methods; heavy metals were determined by use of Atomic Absorption Spectrophotometer method while organic pollutants were determined by Gas chromatography system HP 6890 series. Sulphate was determined by vanadomolybdophosphoric acid method while phosphates and chlorides were determined by argentometric method. Results reveal that effluent pH (4.67 ±0.015), salinity (125 ±4.50 %) and BOD5 (17.83 ±1.70 mg/l) were bellow WHO standard whereas TDS (127.7 ±5.77 mg/l), TSS (563.6 ±3.15 mg/l) and COD (3959 ±3.8 mg/l) were above WHO standards. Heavy metal pollution index (0.31) showed no multi-element contamination arising from effluent. The degree of contamination (1.84) showed that the effluent has a moderate polluting potential. ...
Bulletin of the Chemical Society of Ethiopia, 1999
Journal of Applied Sciences and Environmental Management, 2011
Fluted pumpkin stem waste, which is both a waste and pollutant, was chemically modified with orth... more Fluted pumpkin stem waste, which is both a waste and pollutant, was chemically modified with ortho-phosphoric acid and used to adsorb phenol and chlorophenol in fixed bed micro column It was found that
the carbon bed sorption capacity for phenol and chlorophenol (77.20 and 80.0 mg/g) were higher than the equilibrium sorption studies. The critical bed depth increased with increasing phenol and chlorophenol
concentrations. An increase in phenol and chlorophenol concentration from 100 to 200mg/l increased the rate constant, critical bed depth (Do) and bed sorption capacity, for phenol 77.20 to 160.00mg/g and chlorophenol
80.00 to 173.20mg/g. The breakthrough time, exhaustion time, uptake capacity decreased as the flow rate increased. Chlorophenol and phenol uptake capacity increased with increase in bed height. Experimental data for the change in concentration were correlated using the bed depth service time (BDST) model. In all parameters determined chlorophenol had better adsorption than phenol. Fluted pumpkin is the largest consumed vegetable in the West African sub region and therefore, creates one of the major agro waste problems in Nigeria. Preliminary investigations showed that several tons of these waste are produced daily in market places around the country but scarcely useful and therefore create environmental nuisance. The results obtained could be useful for the application of agricultural wastes for phenol and chlorophenol removal from industrial wastewater
Electronic Journal of Biotechnology, 2006
The sorption kinetics of Pb 2+ and Cu 2+ ions in aqueous solution by unmodified and mercaptoaceti... more The sorption kinetics of Pb 2+ and Cu 2+ ions in aqueous solution by unmodified and mercaptoacetic acid modified biomass of Nypa fruticans shoot has been investigated. The equilibrium sorption capacity of Pb 2+ and Cu 2+ was determined from the Langmuir equation and found to be 15.59 mg/g and 21.85 mg/g for unmodified biomass and 52.86 mg/g and 66.71 mg/g for modified biomass at 30ºC. The time dependent studies showed relatively rapid sorption of 5-10 min to reach equilibrium for both metal ions. A batch sorption model, based on the assumption of the pseudo-secondorder mechanism, was applied to predict the rate constants (g mg-1 min-1), which were found to be 3.59 x 10-4 (Pb 2+) and 1.85 x 10-4 (Cu 2+) and 2.82 x 10-2 (Pb 2+) and 3.67 x 10-2 (Cu 2+) on unmodified and mercaptoacetic acid modified biomass respectively. The activation energy of the sorption of Pb 2+ and Cu 2+ on Nypah palm reveals an endothermic process.
Journal of Nepal Chemical Society, 2013
The study shows that water hyacinth could be used as novel raw material for the production of eff... more The study shows that water hyacinth could be used as novel raw material for the production of effective activated carbon for the adsorption (removal) of Basic Blue- 9 dye from aqueous solution. Optimum removal of 86% dye was obtained which decreased to 62% with an increase in concentration from 50 to 300mg/l, though sorption capacity was found to increase with an increase in concentration. Both Langmuir and Freundlich isotherms were suitable for describing the experimental data in this study with high regression coefficients (R2) of 0.9852 and 0.9905 respectively. The Langmuir maximum sorption capacity (qm) was found to be 421mg/g. It was further observed that the intensity of adsorption, n, was found to be 1.84 which shows that the sorption process was favourable. The equilibrium parameter, RL, value of 0.138 also shows that the adsorption of Basic Blue-9 dyes onto the activated carbon was favourable. The macropore and micropore diffusion constants show that the rate limiting step ...
International Journal of Biological and Chemical Sciences, Oct 5, 2010
This study investigated column and batch sorption of methylene blue from solution using activated... more This study investigated column and batch sorption of methylene blue from solution using activated carbon produced from water spinach. The equilibrium data of the batch sorption process was analyzed using Langmuir and Freundlich isotherm models and the monolayer sorption capacity (441 mg/g) obtained from the Langmuir plot was compared with the column sorption capacity (456 mg/g) obtained from the BDST model plot. The effect of three process variables (carbon bed height, initial methylene blue concentration and flow rate) on the dynamic sorption of methylene blue on carbon was studied using breakthrough curve. From the BDST model analysis it was found that; an increase in dye concentration from 200 to 300 mg/l increased the column sorption capacity (N 0) from 371 to 478 mg/g while an increase in flow rate from 2 to 6 ml/min decreased the column sorption capacity (N 0) from 456 to 253 mg/g respectively. The correlation coefficient (R 2) values obtained from the BDST model plots were generally very high with values ranging from 0.99 to 1.000 indicating the validity of the BDST model for the present system.
Analysis of arsenic in oysters using reversed phase HPLC-ICPMS/ ESI-Orbitrap-MS
Ife Journal of Science, 2016
The ability of NaOH-activated carbon derived from cassava peels waste to remove MY from aqueous s... more The ability of NaOH-activated carbon derived from cassava peels waste to remove MY from aqueous solution was carried out in a fixed-bed column adsorber. The parameters studied included initial solution concentration, Co, carbon bed height and volume flow rate. The temperature of operation and initial solution pH were 29 °C and 5.32 respectively. The optimum adsorption capacity, qe 4.12 mg/g was obtained at Co 10mg/L, bed height 10cm and flow rate, 13.3ml/min. Experimental data were analyzed with Langmuir, Freundlich and Temkin isotherm, as well as the Thomas, YoonNelson and Clark kinetic models. All the models were good fits for experimental data based on correlation coefficient, R 2 values. The ΔGads and Freundlich n (1.587) show that the biosorption was spontaneous, good and physical. Results show that NaOH-activated carbon from cassava peels has low capacity in the removing MY from aqueous solution.
Sorption of Manganese (II) and Chromium (III) Ions from Aqueous Solution Using Water Hyacinth Biomass (Eichhornia crassipes)
Journal of environmental science & engineering, Nov 30, 2010
The use of water hyacinth biomass as adsorbent for Cr(superscript 3+) and Mn(superscript 2+) ions... more The use of water hyacinth biomass as adsorbent for Cr(superscript 3+) and Mn(superscript 2+) ions from aqueous solution by means of batch-adsorption technique was investigated to determine the potential ability of the biomaterial for metal ion removal. The equilibrium isotherm study showed that the maximum monolayer coverage on the biomass surface was 0.933 mg•g^(-1) and 0.874 mg•g^(-1) for Mn(superscript 2+) and Cr(superscript 3+) ions respectively. The highest percentage of Cr(superscript 3+) and Mn(superscript 2+) ions adsorbed by the biomass was 86.4% and 82.6% at the optimum pH of 4.0 and 6.0 respectively. The results also showed that the highest percentage removal 82.5% and 78.3% was obtained at 30 and 20 minutes respectively for Cr(superscript 3+) and Mn(superscript 2+) ions. The sorption process was examined by means of the Langmuir model. The adsorption equilibrium data were found to follow the Langmuir isotherm model with high coefficients of determination (R^2=0.990 and 0.999) for Cr(superscript +) and Mn(superscript 2+) ions respectively. The adsorption capacity of water hyacinth showed that water hyacinth will be useful in recovering chromium (Ⅲ) and manganese (Ⅱ) ions from solution and their subsequent removal from industrial effluents.
Preparation and characterization of activated carbon from water hyacinth (Eichornia Crassipes) and water spinach (Ipomoea Aquatica)
Scientia Africana, 2011
Analysis of arsenic in oysters using reversed phase HPLC-ICPMS/ ESI-Orbitrap-MS
Ife Journal of Science, 2016
Total metal concentrations and five-stage sequential extraction schemes were employed to investig... more Total metal concentrations and five-stage sequential extraction schemes were employed to investigate the potential environmental risk of six important metals in sediments from the upper reaches of Imo River system in Southeastern Nigeria. The concentrations of trace metals in each fraction were determined using AANALYST 400 Perkin-Elmer AAS. The average concentrations (mg/kg) for the six metals in dry season sediment samples were 0.30 ± 0.09 (Cd), 2.28 ± 1.20 (Cu), 12.35 ±8.97 (Zn), 1.79 ± 0.74 (Ni), 3.52 ± 1.68 (Pb), and 2025.72 ± 304.43 (Fe), while the mean metal concentrations (mg/kg) in wet season samples were 0.29 ± 0.05 (Cd), 2.06 ± 0.74 (Zn), 24.57 ± 5.78 (Cu), 5.79 ±1.67 (Ni), 6.26 ± 3.73 (Pb), and 2534 ± 476.98 (Fe) respectively. Fe and Pb content in river sediments exceed the Federal Environmental Protection Agency (FEPA) regulatory Standards for soil. Chemical speciation study applying the five-stage sequential extraction schemes revealed that Cd in sediment prevails most...
Journal of Drug Design and Medicinal Chemistry, 2019
The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oi... more The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oil-producing communities (Oboburu, Obagi, and Ogbogu) in Egi, Niger Delta were assessed for variability, origin and health risks. The result showed that tPAHs of Oboburu were 1344±1685 mg/kg for carcinogenic while BaP (257.3±270.5 mg/kg) had the greatest value. Obagi had 4154±3461 mg/kg for cPAHs with BkF (861.5±543.7 mg/kg) having the greatest amount. Ogbogu was 354.7±360.7 mg/kg for total cPAHs while BgP (104.1±141.8 mg/kg) had highest amount. The dominant PAHs were BbF, BkF, DbA, BaP, IdP and BgP. The principal component analysis (PCA) indicated that the PAHs were majorly of pyrogenic and petrogenic origin. The predicted risk due to PAHs in soil for children showed tPAHs was 1.68E-2, with high risk for BaP (9.05E-3), IdP (5.05E-3), BbF (1.63E-3) and BkF (1.04E-3), while the adults estimation showed tPAHs was 1.13E-2 and high risk were for BaP (2.30E-3), IdP (1.08E-3) and BkF (2.57E-4). These values are more than the limit of the US EPA risk management criterion (10-6 to 10-4) where management decisions should be considered. The trend indicated that their presence in the environment makes it unsafe for the dwellers.
Science Journal of Analytical Chemistry, 2019
The study was to identify the source and evaluate the health risk of heavy metals in contaminated... more The study was to identify the source and evaluate the health risk of heavy metals in contaminated agricultural soil from Egi community (Oboburu, Obagi and Ogbogu), Niger Delta, Nigeria. Multivariate and health risk equations were employed to achieve this. The mean of heavy metals in samples of Oboburu indicated high levels for Fe (271.0±156.6 mg/kg), Pb (111.2±94.97 mg/kg), and Mn (27.92±23.80 mg/kg), Obagi was high for Fe (248.4±175.9 mg/kg), Mn (80.46±12.40 mg/kg), and Co (116.3±193.7 mg/kg), and Ogbogu was high for Fe (160.9±150.3 mg/kg), Co (240.1±412.1 mg/kg), and Mn (42.90±16.82 mg/kg) respectively. Geo-accumulation index indicated that Pb, Cd and Co was of high contamination and the enrichment factor showed that metals were of anthropogenic sources. The Principle component analysis revealed three (3) components accounting for 88.448%, which revealed that the contamination in the sample was more of anthropogenic than biogenic. The Cancer Risk estimate for children population was of high risk for Ni, Cr, Cd and Pb (10-5 to 10-6) while adult population was 10-6 and lower. The non-carcinogenic risk indicated highest value for children in Co (2.75), Pb (1.70E-1) and Fe (1.32E-1), while adult in Co (1.007) and Fe (3.29E-2). The findings suggest human activities have contributed greatly to the contamination of the agricultural soil and usage of such may be of risk to the users.
Journal of Applied Sciences and Environmental Management, 2020
The chemical speciation of five heavy metals [HMs] in spent sand-filter-media [SFM] waste dumpsit... more The chemical speciation of five heavy metals [HMs] in spent sand-filter-media [SFM] waste dumpsite was investigated with a view to ascertain their distribution and chemical availability of the heavy metals in the dumpsite. Samples were collected at the surface, 100cm depth of the dumpsite and 100m away from the dumpsite and analysed using FAAS for total concentration of Cr, Fe, Mn. Ni and Pb. Speciation analysis was carried out usingmodified Tessier’s sequential extraction method. The percentage concentrations showed that Pb occurred more at the exchangeable fraction with 90.6% at the top, 91.34% at 100cm depth. This signifies that Pb is biochemically available for in-take by living organisms. Fe had the highest concentration by mass 12mg/g but its occurrence of between 22- 28% is in the residual/inert fraction. Ni had 40% in the exchangeable and carbonate fractions at the surface and at 100cm depth. Cr had highest exchangeable fraction of 46.29% and 45.59% at the surface and 100cm...
International Research Journal of Pure and Applied Chemistry, 2019
The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution ha... more The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Theref...
Journal of Applied Sciences and Environmental Management, 2019
This study assessed the physicochemical characteristics and toxicity of water-accommodated fracti... more This study assessed the physicochemical characteristics and toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of Bonny Light Crude oil and Dispersit SPC 1000 (dispersant) to Mudskipper fish (Periophthalmus Papilio). There were variations in the levels of the physicochemical parameters. The coefficient of variation (CV) indicated that the temperature show the least variation of 2.24% and salinity the highest 98.12%.Hypothesis test for significant differences at p < 0.05 significance level however, showed that there were no significant differences in the levels of the measured parameters over the 96 hours. All the mudskippers fish samples exposed to the water accumulated water fraction of 10% bonny oil survived beyond 96 hours. An increase in toxicity of the oil was observed after 72-96 hour exposures of the mudskipper to the oil and dispersant CEWAF. For dispersant concentrations of 540 ml/L and 630 ml/L the survival of mudskippers was 80%. These mortalities might be due to the toxic effect of the dispersant, Dispersit SPC 1000.The Total Petroleum Hydrocarbon (TPH) and the Polycyclic Aromatic Hydrocarbon (PAH) in the test media were respectively 7.66-63.18 ppm and 0.82-5.26 ppm.10% Bonny light crude oil WAF had no effects on mudskipper survival. Exposures to 540 ml/L and 630 ml/L Dispersit SPC 1000 dispersed oil WAF (CEWAF) resulted in 20 % mortality. The lethal dose concentration was 885.5 ml/L (88.55%). The lowest observed effect concentration (LOEC) was found to be 540 ml/L.
Journal of Applied Sciences and Environmental Management, 2019
Marine oil spillage accidents greatly impact major risks to the environment in terms of the acute... more Marine oil spillage accidents greatly impact major risks to the environment in terms of the acute and chronic adverse effects not only to the offshore, but also the coastal ecosystem. This study assessed single and joint toxicological effect of Dispersit SPC 1000 and Bonny Oil on mudskipper fish (Periophthalmus papilio) from the brackish water research station of African Regional Aquaculture Centre, Buguma, Rivers State, Nigeria. The physicochemical parameters observed throughout the study were the pH, alkalinity and salinity were 6.83 ± 0.1, 40 mg/L± 0.2 and 17,655 mg/L respectively. The temperature and Dissolved oxygen (D.O.) and specific gravity averaged 26.7 o C ± 0.1, 5.70 mg/L ± 0.02 and 1.008 ± 0.001, respectively. Dispersit SPC 1000 was found to be toxic to the mudskipper at various % (v/v) concentration, above 60 % (v/v) concentration no fish survived after one hour. The relation between the probit mortality and log concentration showed a strong positive correlation between the dispersant concentration and fish mortality within 3 hours, with r 2 = 0.813 p = 0.05;The lethal dose Lc50 was 73.48%. Within 6 hours, the mortality increased as the dispersant exposure concentration was increased (r 2 = 0.872, p =0.05). The results of exposure of the mudskippers to the water-oil-dispersant mix (CEWAF) showed lower mortalities. Mortality was observed after 72 hours for dispersant concentration above 54 %. 63% dispersant concentrations, 20% mortalities was observed between 72 and 96 hours. Dispersit SPC 1000 alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant. There was no joint increase in toxicity between bonny oil and the chemical dispersant, as the mixing of the dispersant by the oil resulted in diminished toxicity of CEWAF and lower mortality.
International Journal of Biological and Chemical Sciences, 2010
Batch adsorption experiments were performed to study the removal kinetics of Basic Blue-9 dye fro... more Batch adsorption experiments were performed to study the removal kinetics of Basic Blue-9 dye from aqueous solution using activated carbon produced from water spinach. The percent removal of dye increased with time and attained equilibrium in 3 hrs and 20 mins for an initial dye concentration of 250 mg/l. Optimum removal of 96% dye was achieved at the equilibrium time of 200 mins. The equilibrium sorption capacity (q e1) obtained from the pseudo-first order linear plot was 2.75 mg/g with a rate constant, K 1 of 0.0115 g/ (mg/min. The experimental data was most suitably analyzed by the pseudo-second order model with a regression coefficient (R 2) value of 0.9949. The initial sorption rate, h o was found to be 0.095 mg/g min with an equilibrium sorption capacity (q e2) of 4.80 mg/g. The correlation coefficients R 2 1 and R 2 2 , for the first-and second-order equations were all high (>0.97), suggesting the suitability of both models for the experimental data.
Differential sorption behaviour of pure and acid treated pumpkin waste biomass on the sorption of... more Differential sorption behaviour of pure and acid treated pumpkin waste biomass on the sorption of Ni 2+ ion from aqueous solution was assessed by an ensemble of sorption techniques. Biomass was chemically treated by 0.50 N and 1.00 N 2-mercaptoethanoic acid solutions. Sorption capacity calculations from Langmuir isotherm model reveals the following amounts of Ni 2+ ions bound per gram of biomass: pure, 12.69; 0.5 N acid treated, 40.0; and 1.0 N acid treated, 42.19 mg/g. The sorption probabilities for Ni 2+ onto pure and differentially acid treated biomass were 0.19, 0.22 and 0.31 respectively. Acid treatment significantly enhanced the adsorption potential, adsorption density and sorption probability of biomass towards the metal ion. The negative values of E a suggest that sorption process is exothermic. This study demonstrates that fluted pumpkin waste could be utilized as low cost, environment friendly biosorbent for the removal of Ni 2+ and other trace metals from aqueous solution.
International Letters of Chemistry, Physics and Astronomy, 2014
Five composite samples of waste water were collected from waste water tank of a vegetable oil ref... more Five composite samples of waste water were collected from waste water tank of a vegetable oil refining company and were analyzed for physiochemical characteristics, heavy metal and organic pollutants. Physicochemical determinations were done according to standard methods; heavy metals were determined by use of Atomic Absorption Spectrophotometer method while organic pollutants were determined by Gas chromatography system HP 6890 series. Sulphate was determined by vanadomolybdophosphoric acid method while phosphates and chlorides were determined by argentometric method. Results reveal that effluent pH (4.67 ±0.015), salinity (125 ±4.50 %) and BOD5 (17.83 ±1.70 mg/l) were bellow WHO standard whereas TDS (127.7 ±5.77 mg/l), TSS (563.6 ±3.15 mg/l) and COD (3959 ±3.8 mg/l) were above WHO standards. Heavy metal pollution index (0.31) showed no multi-element contamination arising from effluent. The degree of contamination (1.84) showed that the effluent has a moderate polluting potential. ...
Bulletin of the Chemical Society of Ethiopia, 1999
Journal of Applied Sciences and Environmental Management, 2011
Fluted pumpkin stem waste, which is both a waste and pollutant, was chemically modified with orth... more Fluted pumpkin stem waste, which is both a waste and pollutant, was chemically modified with ortho-phosphoric acid and used to adsorb phenol and chlorophenol in fixed bed micro column It was found that
the carbon bed sorption capacity for phenol and chlorophenol (77.20 and 80.0 mg/g) were higher than the equilibrium sorption studies. The critical bed depth increased with increasing phenol and chlorophenol
concentrations. An increase in phenol and chlorophenol concentration from 100 to 200mg/l increased the rate constant, critical bed depth (Do) and bed sorption capacity, for phenol 77.20 to 160.00mg/g and chlorophenol
80.00 to 173.20mg/g. The breakthrough time, exhaustion time, uptake capacity decreased as the flow rate increased. Chlorophenol and phenol uptake capacity increased with increase in bed height. Experimental data for the change in concentration were correlated using the bed depth service time (BDST) model. In all parameters determined chlorophenol had better adsorption than phenol. Fluted pumpkin is the largest consumed vegetable in the West African sub region and therefore, creates one of the major agro waste problems in Nigeria. Preliminary investigations showed that several tons of these waste are produced daily in market places around the country but scarcely useful and therefore create environmental nuisance. The results obtained could be useful for the application of agricultural wastes for phenol and chlorophenol removal from industrial wastewater
Electronic Journal of Biotechnology, 2006
The sorption kinetics of Pb 2+ and Cu 2+ ions in aqueous solution by unmodified and mercaptoaceti... more The sorption kinetics of Pb 2+ and Cu 2+ ions in aqueous solution by unmodified and mercaptoacetic acid modified biomass of Nypa fruticans shoot has been investigated. The equilibrium sorption capacity of Pb 2+ and Cu 2+ was determined from the Langmuir equation and found to be 15.59 mg/g and 21.85 mg/g for unmodified biomass and 52.86 mg/g and 66.71 mg/g for modified biomass at 30ºC. The time dependent studies showed relatively rapid sorption of 5-10 min to reach equilibrium for both metal ions. A batch sorption model, based on the assumption of the pseudo-secondorder mechanism, was applied to predict the rate constants (g mg-1 min-1), which were found to be 3.59 x 10-4 (Pb 2+) and 1.85 x 10-4 (Cu 2+) and 2.82 x 10-2 (Pb 2+) and 3.67 x 10-2 (Cu 2+) on unmodified and mercaptoacetic acid modified biomass respectively. The activation energy of the sorption of Pb 2+ and Cu 2+ on Nypah palm reveals an endothermic process.
Journal of Nepal Chemical Society, 2013
The study shows that water hyacinth could be used as novel raw material for the production of eff... more The study shows that water hyacinth could be used as novel raw material for the production of effective activated carbon for the adsorption (removal) of Basic Blue- 9 dye from aqueous solution. Optimum removal of 86% dye was obtained which decreased to 62% with an increase in concentration from 50 to 300mg/l, though sorption capacity was found to increase with an increase in concentration. Both Langmuir and Freundlich isotherms were suitable for describing the experimental data in this study with high regression coefficients (R2) of 0.9852 and 0.9905 respectively. The Langmuir maximum sorption capacity (qm) was found to be 421mg/g. It was further observed that the intensity of adsorption, n, was found to be 1.84 which shows that the sorption process was favourable. The equilibrium parameter, RL, value of 0.138 also shows that the adsorption of Basic Blue-9 dyes onto the activated carbon was favourable. The macropore and micropore diffusion constants show that the rate limiting step ...
International Journal of Biological and Chemical Sciences, Oct 5, 2010
This study investigated column and batch sorption of methylene blue from solution using activated... more This study investigated column and batch sorption of methylene blue from solution using activated carbon produced from water spinach. The equilibrium data of the batch sorption process was analyzed using Langmuir and Freundlich isotherm models and the monolayer sorption capacity (441 mg/g) obtained from the Langmuir plot was compared with the column sorption capacity (456 mg/g) obtained from the BDST model plot. The effect of three process variables (carbon bed height, initial methylene blue concentration and flow rate) on the dynamic sorption of methylene blue on carbon was studied using breakthrough curve. From the BDST model analysis it was found that; an increase in dye concentration from 200 to 300 mg/l increased the column sorption capacity (N 0) from 371 to 478 mg/g while an increase in flow rate from 2 to 6 ml/min decreased the column sorption capacity (N 0) from 456 to 253 mg/g respectively. The correlation coefficient (R 2) values obtained from the BDST model plots were generally very high with values ranging from 0.99 to 1.000 indicating the validity of the BDST model for the present system.
Analysis of arsenic in oysters using reversed phase HPLC-ICPMS/ ESI-Orbitrap-MS
Ife Journal of Science, 2016