Papers by AYEBAEMI I SPIFF
Journal of the National Science Foundation of Sri Lanka, 2017
Physicochemical characteristics are essential in assessing the performance indices of potential b... more Physicochemical characteristics are essential in assessing the performance indices of potential biocarbons. In an attempt to find the feasibility of developing an eco-friendly and economically sustainable adsorbent for the removal of contaminants from industrial wastewater; the physicochemical characteristics of biocarbons generated from Nipa palm (Nypa fruticans Wurmb) leaves at the same carbonization temperature with differential chemical - modifications were investigated using standard testing methods. The differentially modified biocarbons were obtained through single step pyrolysis after saturating the biocarbons with H 2O, H 2SO 4 and KOH. The domino-effects obtained show that maximum biocarbon yield of 46.6 ± 0.21 % was recorded for basic reagent surface-modified biocarbon (BAC) followed by acidic reagent modified biocarbon (AAC) with a value of 35.1 ± 0.19%) and physically carbonized biocarbon (PCC) respectively. The data showed that, amongst the Nipa palm derived biocarbons...
Bulletin of The Chemical Society of Ethiopia, May 8, 2006
The levels of total volatile bases (TVB) and trimethylamine (TMA) formed in three species of sali... more The levels of total volatile bases (TVB) and trimethylamine (TMA) formed in three species of saline water fish stored at-4°C were investigated as indices of spoilage. The data showed that the concentration of TVB (mg/100g sample) in Tilapia spp. ranged from 19.40-61.00; Mugil cephalus 10.30-41.10 and Carassius auratus 12.50-66.7 during the maximum storage period of 20 days, while TMA levels (mg/100g sample) over the same storage period and conditions ranged from < 0.001-7.12 for Tilapia spp., < 0.001-6.45 for Mugil Cephalus and < 0.001-7.28 for Carassious auratus. The data showed that the concentration of TVB and TMA increased with increasing storage time. These data may be used in formulating appropriate food safety limits for consumption of refrigerated fresh fish products in Nigeria.
International Journal of Innovation and Applied Studies, Oct 2, 2015
Soil characteristics and metals contents are important components for playground safety, but thes... more Soil characteristics and metals contents are important components for playground safety, but these are lacking in third world countries. In the present study thirty six soils samples from nine preselected public schools playgrounds were characterized using standards methods. Results revealed poorly equipped and maintained playgrounds with pH < 7 for all playground soils indicating acidic soils while organic matter ranged from Ikenegbu primary school (0.2 %) to World Bank Primary school (2.8%), sodium adsorption ratio ranged from Model Nursery school (0.41 (Cmolkg-1) 05) to Shell camp primary (0.77 (Cmolkg-1) 05). Other physicochemical characteristics had values comparable to those of typical acid sand derived soils whose textural class is sandy loam. Electrical conductivity varied widely amongst playgrounds ranging from Housing Estate primary school (3.2 S/cm) to Shell Camp Primary school (9.5 S/cm) indicating presence of some soluble inorganic salts. These soils characteristics therefore constitute major favorable conditions for the release of toxic metals in the soil or runoffs.
Journal Of Chemical Society Of Nigeria, Mar 17, 2015
Children at playgrounds are exposed to contaminants and so attempts to improve children's environ... more Children at playgrounds are exposed to contaminants and so attempts to improve children's environment could reduce environmental burden of illnesses. In order to assess contamination by heavy metals, 36 soil samples were collected from nine public schools within Owerri metropolis. Using AAnalyst 400 Perkin Elmer (AAS)
The influence of initial metal ion concentration of the batch sorption of Pb 2+ and Cd 2+ onto a ... more The influence of initial metal ion concentration of the batch sorption of Pb 2+ and Cd 2+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were 49.53 and 65.50 mM/g for Pb 2+ and Cd 2+ , respectively The data further showed that, sorption of the two divalent metals onto the biomass increased with increase in initial metal ion concentration until monolayer coverage is attained. The thermodynamic assessment of the metal ion-Caladium bicolor biomass system indicates the feasibility and spontaneous nature of the process and Go was evaluated as ranging from-4.55 to-6.63 KJ mol-1 and-4.02 to-6.09 KJ mol-1 for Pb 2+ and Cd 2+ sorption, respectively. The order of magnitude of the G o values indicates an ion-exchange physisorption process.
Asian Journal of Water, Environment and Pollution, 2005
Journal of the National Science Foundation of Sri Lanka, 2017
The rate of backward extraction of the tris-(nitropyrazolonato) iron(lI1) chelate, Fe(NF'z)3 from... more The rate of backward extraction of the tris-(nitropyrazolonato) iron(lI1) chelate, Fe(NF'z)3 from the organic phase has been studied under various conditions. Experimental data show that the rate of stripping iron(1ll) chelate is first order with respect to [ F~(N P z)~] , ,~ and [H+], and inverse first order dependent on [HNPzIorg. The rate of backward extraction is believed to be controlled by the dissociation of the iron(II1) monopyrazolonate cation to ~e~+ and NPz-. The rate constant, kb for the stripping process was determined to be 2.7 x 10~s-'.
Bulletin of the Chemical Society of Ethiopia, 2005
Kinetic investigations are necessary for determining the rate of reaction and mechanism. The kine... more Kinetic investigations are necessary for determining the rate of reaction and mechanism. The kinetics of the sorption of Pb<sup>2+</sup> and Cd<sup>2+</sup> from aqueous solution on to the biomass of <i>C. bicolor</i> was studied by batch equilibrium technique. The removal of the two metal ions was found to be > 60% depending on the initial metal ion concentration during the contact time. The maximum sorption was found to be 75.11 mg/g and 25.30 mg/g for Pb<sup>2+</sup> and Cd<sup>2+</sup> at an equilibrium contact time of 150 min. The process of uptake is governed by film-diffusion controlled pseudo-second order reversible rate kinetics. The sorption capacity at any contact time has been evaluated and a Langmuir-type model equation has been developed to predict the optimized minimum operating time to determine a specific amount of metal ion sorption.
Discovery and Innovation, 2005
Bulletin of the Chemical Society of Ethiopia, 1999
American Journal of Transplantation, 2013
Calcineurin-inhibitor refractory bronchiolitis obliterans (BO) represents the leading cause of la... more Calcineurin-inhibitor refractory bronchiolitis obliterans (BO) represents the leading cause of late graft failure after lung transplantation. T helper (Th)2 and Th17 lymphocytes have been associated with BO development. Taking advantage of a fully allogeneic trachea transplantation model in mice, we addressed the pathogenicity of Th cells in obliterative airway disease (OAD) occurring in cyclosporine A (CsA)-treated recipients. We found that CsA prevented CD8 + T cell infiltration into the graft and downregulated the Th1 response but affected neither Th2 nor Th17 responses in vivo. In secondary mixed lymphocyte cultures, CsA dramatically decreased donor-specific IFN-c production, enhanced IL-17 production and did not affect IL-13. As CD4 + depletion efficiently prevented OAD in CsA-treated recipients, we further explored the role of Th2 and Th17 immunity in vivo. Although IL-4 and IL-17 deficient untreated mice developed an OAD comparable to wild-type recipients, a single cytokine deficiency afforded significant protection in CsA-treated recipients. In conclusion, CsA treatment unbalances T helper alloreactivity and favors Th2 and Th17 as coexisting pathways mediating chronic rejection of heterotopic tracheal allografts.
AFRICAN JOURNAL OF BIOTECHNOLOGY
The ability of cassava waste biomass (untreated and acid treated) to remove heavy metals (Cu(II) ... more The ability of cassava waste biomass (untreated and acid treated) to remove heavy metals (Cu(II) and Zn(II)) from single-ion solution and wastewater was investigated. All experiments were conducted using 10mM solutions of mixed metal ions of CuSO 4 .5H 2 O and ZnCl 2. The uptake capacities of the two metal ions tested on the untreated and acid treated cassava waste biomass were 71.3 and 85.2 mg/g for Cu(II), and 43.4 and 58.1 mg/g for Zn(II) in single-ion solution. For wastewater, the uptake capacities of untreated and acid treated biomass was found to be 40.1 and 59.7 mg/g for Cu(II), and 38.6 and 38.7 mg/g for Zn(II), respectively. Metal ion uptake capacities in wastewater were lower than in single-ion solution probably due to competition of metal ions of different sizes on available binding sites. Uptake capacities of these metal ions on the biomass surface increased with acid treatment. Equilibrium sorption studies showed that the extent of metal uptake was enhanced by chemically modifying the cassava waste biomass by thiolation. Cassava waste biomass saturated with metal ions shows remarkable ability for metal recovery by dilute acid treatment, and can be used repeatedly for removal of heavy metals in single-ion solution and in wastewater effluents.
Batch adsorption technique was used to ascertain the most favorable conditions for the reduction ... more Batch adsorption technique was used to ascertain the most favorable conditions for the reduction of chemical oxygen demand (COD) of 2-(N,N-Dimethyl-4-aminophenyl)-azo-benzene carboxylic acid (DMABA) in aqueous solution using physically carbonized carbon (PCC) and neutral reagent surface-modified carbon (NAC) obtained from locally available and environment nuisance Nypa fruticans plant. The maximum adsorption capacity in terms of COD reduction of aqueous DMABA was computed by Langmuir adsorption isotherm as 62.57 and 46.11 mg/g for PCC and NAC, respectively. The most favorable agitation conditions at 30oC for the batch adsorption process were 150 rpm and 100 min. The adsorption of DMABA onto PCC and NAC was found to be physisorption, and the overall process assessed by the Gibbs free energy (ΔGo) was to some extent exergonic. The study revealed that Nipa fruticans plant is capable of being transformed into highquality novel carbon for clean-up of synthetic organic chemicals (SOCs) in...
Despite being the largest morphological part of fluted pumpkin, the seed shell has not been put i... more Despite being the largest morphological part of fluted pumpkin, the seed shell has not been put into use either by man or animal. In the present study fluted pumkin seed shell was subjected to proximate, phytochemicals, elemental and antinutritional analysis and results compared to standard values. Proximate composition showed crude fibre, (8.24±0.22); carbohydrates, (64.91±3.07); fat and oil, (2.271±0.31); crude proteins (5.23±1.63); moisture, (9.63±1.17) and ash content (11.63±0.56). Elemental analysis showed that apart from organic carbon (30.88±0.90) sodium, (23.2±0.72); iron, (7.94±1.56); copper, (8.1±2.40); zinc, (3.0±15) and chromium (0.71±0.01) were appreciable, suggesting that the mesocarp could be a source of mineral. Alkaloids, saponins, flavonoids, and tannins were present while toxicants in mg/100g showed oxalate, (17.81±1.60) phytate, (12.20±2.10) and hydrocyanide, (0.80±0.03). Results suggest possible utilisation of the fluted pumpkin seed shell as a food source, in medicine and as activated carbon precursor. However, antinutritional to nutrient ratios and other factors such as Na/K (38.8) could be the reason why the seed shell is not edible.
Effect of metal ion concentration on the biosorption of Pb2+ and Cd2+ by Caladium bicolor (wild c... more Effect of metal ion concentration on the biosorption of Pb2+ and Cd2+ by Caladium bicolor (wild cocoyam)
The influence of initial metal ion concentration of the batch sorption of Pb 2+ and Cd 2+ onto a ... more The influence of initial metal ion concentration of the batch sorption of Pb 2+ and Cd 2+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were 49.53 and 65.50 mM/g for Pb 2+ and Cd 2+ , respectively The data further showed that, sorption of the two divalent metals onto the biomass increased with increase in initial metal ion concentration until monolayer coverage is attained. The thermodynamic assessment of the metal ion – Caladium bicolor biomass system indicates the feasibility and spontaneous nature of the process and ΔGo was evaluated as ranging from –4.55 to –6.63 KJ mol -1 and –4.02 to –6.09 KJ mol - for Pb 2+ and Cd 2+ sorption, respectively. The order of magnitude of the ΔGo values indicates an ion-exchange physisorption process. African Journal of Biotechnology Vol. 4 (2), pp. 191-196, 2005
... According to Giles classification as reported by Vinod and Anirudhan (2001), the adsorption i... more ... According to Giles classification as reported by Vinod and Anirudhan (2001), the adsorption isotherms for all temperatures may be further classified into several ... MANJU GN; RAJI, C. and ANIRUDHAN, TS Evaluation of coconut husk carbon for the removal of arsenic from water. ...
Journal of Scientific & Industrial Research, 2005
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 0.50N 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 solut...
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Papers by AYEBAEMI I SPIFF