Nnaemeka Okorocha - Academia.edu (original) (raw)

Papers by Nnaemeka Okorocha

Multidisciplinary Journal for Applied Research in Engineering and Technology, 2022

Some varieties of monoazo disperse dyes derived from halogenated arylamines were synthesized by s... more Some varieties of monoazo disperse dyes derived from halogenated arylamines were synthesized by simple diazotization and coupling to 1 and 2-naphthols. The impure dyes were recrystallized from ethanol solvent. Interestingly, all the dyes synthesized have colouristic properties. The purity and structural identities of the dyes obtained were confirmed by melting point, UV and IR spectrometry. The UV spectra of all the dyes synthesized revealed solvatochromism in solvent of different polarities and also halochromism. Fastness properties showed that all the dyes had better fastness properties on cotton than on nylon fabric, although deep dyeing was obtained on nylon fabric.

International Letters of Chemistry, Physics and Astronomy

The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite ... more The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmu...

Pigment & Resin Technology

Purpose This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelot... more Purpose This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelotii (LH) on mild steel in 1 M HCl and 0.5 M H2SO4 using weight loss and potentiodynamic polarization techniques. Design/methodology/approach Water extract of LH was used as corrosion inhibitor on mild steel in acidic media at room temperature and elevated temperatures (30-60°C). Various concentrations of the plant extract were prepared from the stock solution obtained after solvent extraction. The inhibition efficiency of LH extract was evaluated and mechanism of adsorption was deduced. Findings LH extract showed significant corrosion inhibition on mild steel in both acidic media, with inhibition efficiency increasing with extract concentration. Potentiodynamic polarization measurements revealed mixed inhibition mechanism. Optimum inhibition efficiency was recorded at 2500 mg/L after 288 h. Mechanism of adsorption was mainly of physisorption. The inhibitor exhibited good inhibition effici...

International Letters of Chemistry, Physics and Astronomy

The potential of Calcinated and uncalcinated zinc oxide as effective Photocatatlyst for the degra... more The potential of Calcinated and uncalcinated zinc oxide as effective Photocatatlyst for the degradation of malachite green dye, MG from aqueous medium using UV light has been identified. The photocatalysts were characterized using scanning electron microscope, SEM and x-ray diffraction, XRD. The SEM investigations of the calcinated ZnO revealed highly dispersed nanomaterials and the particles were of nanometer size in agreement with the XRD result. The uncalcinated zinc oxide, ZnO revealed some pronounced nanoparticles. The degradation of MG by the photocatalyst was found to be influenced by adsorbent loading and irradiating time. The optimum degradation was obtained at 0.5g catalyst loading of both calcinated and uncalcinated zinc oxide which is 98.48% and 96.31 % respectively at 150 minutes. The degradation kinetics conformed to the pseudo-first-order kinetic model. The present study showed that calcinated and uncalcinated zinc oxide ZnO can be effectively used as efficient photoc...

International Letters of Chemistry, Physics and Astronomy

The adsorption of methylene blue (MB) dye on bush cane bark powder has been studied by analyzing ... more The adsorption of methylene blue (MB) dye on bush cane bark powder has been studied by analyzing the effect of contact time, initial dye concentration, adsorbent dose, pH, and temperature on the amount of the MB dye adsorbed per unit mass of the bush cane bark powder adsorbent. An optimum adsorption could be achieved during 80 min contact time but, thereafter, decreased with contact time beyond 80 min. The adsorption of the methylene blue dye increased with increasing the initial dye concentration, temperature and pH. However, the amount of methylene blue adsorbed decreased with increasing the dosage of the adsorbent; a phenomenon attributed to a plausible agglomeration of the adsorbent and blocking of the preferred adsorption sites with increasing adsorbent dosage. The adsorption mechanism of the dye obeyed the Freundlich isotherm. Kinetic studies showed that the methylene blue adsorption onto bush cane bark powder adsorbent followed a second order reaction kinetics. The adsorbent ...

International Letters of Chemistry, Physics and Astronomy, 2017

The potential of white potato peel powder for the removal of methyl red (MR) dye from aqueous sol... more The potential of white potato peel powder for the removal of methyl red (MR) dye from aqueous solution was investigated. The adsorbent was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MR onto the adsorbent (WPPP) was found to be contact (80 mins), pH (2) and temperature (303K) for an initial MR dye concentration of 50mg/l and adsorbent dose of 1.0g. The experimental equilibrium adsorption data of the (MR) dye fitted best and well to the Freundlich isotherm model. The maximum adsorption capacity was found to be 30.48mg/g for the adsorption of MR. The kinetic data conforms to the pseudo – second order kinetic model.

International Letters of Natural Sciences, 2016

In order to estimate plant available fraction of metals in two soil samples-contaminated soil (A)... more In order to estimate plant available fraction of metals in two soil samples-contaminated soil (A) and non-contaminated soil (B), a vegetable crop,Curcubita ficifoliawas grown on both soil samples. The matured leaf was harvested and analyzed for its metal concentration after three (3) months of growth. The soil samples were collected before and after planting, digested with acid and analyzed to determine the pseudo total metal concentration and quantification was done using atomic absorption spectroscopy (AAS). To correlate metal accumulation by the vegetable with potential bioavailability of metals in soils, sequential extraction (SE) using the modified BCR technique was performed on the soils. Soil sample B was used for quality control. It was observed that each metal differed considerably in uptake. And theC. ficifoliacultivated on soil sample A had tissue concentrations of Zn, Mn and Cu as follows: 39.6mgkg-1, 18.3mgkg-1and 26.3mgkg-1respectively. Also,C. ficifoliacultivated on s...

International Letters of Chemistry, Physics and Astronomy, 2016

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red... more The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22...

IOSR Journal of Applied Chemistry, 2016

The removal of Crystal Violet (CV) dye with the powder of picrilima nitida stem bark (PNSBP) has ... more The removal of Crystal Violet (CV) dye with the powder of picrilima nitida stem bark (PNSBP) has been demonstrated based on adsorption parameters like contact time, initial dye concentration, adsorbent dose, pH, and temperature. The adsorbent was characterized by FTIR and SEM analysis. Equilibrium amount of CV dye adsorbed per unit mass of PNSBP adsorbent, qe (mg/g), occurred after 60 min. contact time. The q e values increased with increasing initial CV dye concentration from 25 mg/L to 125 mg/L, and with pH increasing from 2 to 10. However, the q e value continuously decreased as temperature increased from 30 o C to 70 o C and PNSBP adsorbent dosage from 0.5 g to 4 g. Based on values of correlation coefficient (R 2), the Freundlich isotherm was more appropriate in explaining the mechanism of the CV adsorption onto PNSB. Kinetic studies showed that the CV dye adsorption onto PNSB adsorbent followed the pseudo second order reaction kinetics. Thermodynamic quantities were evaluated and the negative G 0 values obtained indicated spontaneous adsorption process. The negative H 0 and S 0 values obtained indicate the exothermic nature and decrease in randomness during the adsorption process respectively.

IOSR Journal of Applied Chemistry, 2016

The potential of almond seed shell (ASSP), for the removal of methyl violet (MV) dye from aqueous... more The potential of almond seed shell (ASSP), for the removal of methyl violet (MV) dye from aqueous solution was investigated. The adsorbent was characterized by SEM and FTIR analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MV onto the adsorbent (ASSP) was found to be: contact time (80 mins), pH (10.0) and temperature (303 K) for an initial MV dye concentration of 50 mg/L with adsorbent dose of 1.0 g. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for the dye adsorption. The maximum adsorption capacity was found to be 628.93 mg/g for the adsorption of MV dye. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (G 0), enthalpy (H 0) and entropy (S 0) were evaluated and the negative values of G 0 obtained indicated the spontaneous nature of the adsorption processes. The negative H 0 and positive values of S 0 indicate the exothermic nature and increased randomness during the adsorption of MV onto ASSP.

Journal of Radioanalytical and Nuclear Chemistry, 2013

Radionuclide adsorption on clay rocks has in recent years been studied mainly in connection with ... more Radionuclide adsorption on clay rocks has in recent years been studied mainly in connection with their use as sealing barriers in nuclear waste and spent nuclear fuel repositories. In Slovakia we find deposits of bentonites which should be used for the above mentioned purpose. The usability of adsorbents in practical applications depends on the speed of the adsorption process of the adsorbate on the adsorbent surface and distribution ratio. The work objective was the study of the kinetics of Sr adsorption on clay adsorbents with different geological origin. The geological origin of bentonite significantly influences its mineralogical and chemical composition and therein its adsorption properties. The adsorption process of strontium was fast. Adsorption equilibrium was reached for all three samples studied within 1 min from the beginning of the contact between solid and liquid phases. After the adsorption equilibrium was reached there were no more changes in the values of distribution coefficients and the adsorption percentage, and comparable values were reached in the contact-phase time span studied within 10 days. The values of adsorbed strontium were decreasing in the following order: J250 [ L250 [ DV45. The pseudo second-order kinetic models was used to describe model the kinetic data and provided excellent kinetic data fitting (R 2 [ 0.999).

Environmental Progress & Sustainable Energy, 2013

In this work, a continuous fixed-bed adsorption study was carried out by using NaOH-modified rice... more In this work, a continuous fixed-bed adsorption study was carried out by using NaOH-modified rice husk (NMRH) as an adsorbent for the removal of malachite green (MG) from its aqueous solution. The influence of important process parameters such as initial solution pH, influent concentration of MG, feed flow rate, and bed height on breakthrough curve and breakthrough time was investigated. The breakthrough time increased with decreasing flow rate. The same effect was noted when the bed height was increased. On the other hand, the breakthrough time decreased as the inlet dye concentration was increased keeping the flow rate and bed height constant. Four different kinetic models, namely Adams-Bohart, bed depth service time bed depth service time (BDST), Thomas model, and Yoon-Nelson model were fitted to the experimental data. The Thomas model showed best fit at all experimental conditions studied. Overall, this study showed that NMRH has potential for technological application as adsorbent in dye wastewater treatment. 2012 Ameri

International Letters of Chemistry, Physics and Astronomy, 2016

Dextrin produced from cassava was investigated for adsorption on coal during processing. Aluminiu... more Dextrin produced from cassava was investigated for adsorption on coal during processing. Aluminium ion (Al3+) and nitrate ion (NO3-) were employed for adsorption test to improve coal surfaces. The effect of initial concentration, adsorbent dose and pH on dextrin adsorption onto modified coal surface was investigated. Studies concerning the adsorption equilibrium and thermodynamics are presented; the equilibrium data was modelled using Langmuir and Freundlich isotherms. The adsorption equilibrium data was well explained by Freundlich isotherm. The percentage removal was found to be 93.75% and 90.75% at adsorbent dose of 0.2 g for both aluminium sulphate coal bituminous (ACB) and aluminium sulphate coal lignite (ACL) respectively. There was a rapid increase in adsorption of dextrin from low pH of 2 to about pH of 4 with a plateau region from pH 4 to pH 6. Adsorption capacity of 61.25 mg/g and 55.00 mg/g was achieved at initial concentration of 200 mg/L for ACB and ACL respectively. Fo...

Multidisciplinary Journal for Applied Research in Engineering and Technology, 2022

Some varieties of monoazo disperse dyes derived from halogenated arylamines were synthesized by s... more Some varieties of monoazo disperse dyes derived from halogenated arylamines were synthesized by simple diazotization and coupling to 1 and 2-naphthols. The impure dyes were recrystallized from ethanol solvent. Interestingly, all the dyes synthesized have colouristic properties. The purity and structural identities of the dyes obtained were confirmed by melting point, UV and IR spectrometry. The UV spectra of all the dyes synthesized revealed solvatochromism in solvent of different polarities and also halochromism. Fastness properties showed that all the dyes had better fastness properties on cotton than on nylon fabric, although deep dyeing was obtained on nylon fabric.

International Letters of Chemistry, Physics and Astronomy

The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite ... more The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmu...

Pigment & Resin Technology

Purpose This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelot... more Purpose This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelotii (LH) on mild steel in 1 M HCl and 0.5 M H2SO4 using weight loss and potentiodynamic polarization techniques. Design/methodology/approach Water extract of LH was used as corrosion inhibitor on mild steel in acidic media at room temperature and elevated temperatures (30-60°C). Various concentrations of the plant extract were prepared from the stock solution obtained after solvent extraction. The inhibition efficiency of LH extract was evaluated and mechanism of adsorption was deduced. Findings LH extract showed significant corrosion inhibition on mild steel in both acidic media, with inhibition efficiency increasing with extract concentration. Potentiodynamic polarization measurements revealed mixed inhibition mechanism. Optimum inhibition efficiency was recorded at 2500 mg/L after 288 h. Mechanism of adsorption was mainly of physisorption. The inhibitor exhibited good inhibition effici...

International Letters of Chemistry, Physics and Astronomy

The potential of Calcinated and uncalcinated zinc oxide as effective Photocatatlyst for the degra... more The potential of Calcinated and uncalcinated zinc oxide as effective Photocatatlyst for the degradation of malachite green dye, MG from aqueous medium using UV light has been identified. The photocatalysts were characterized using scanning electron microscope, SEM and x-ray diffraction, XRD. The SEM investigations of the calcinated ZnO revealed highly dispersed nanomaterials and the particles were of nanometer size in agreement with the XRD result. The uncalcinated zinc oxide, ZnO revealed some pronounced nanoparticles. The degradation of MG by the photocatalyst was found to be influenced by adsorbent loading and irradiating time. The optimum degradation was obtained at 0.5g catalyst loading of both calcinated and uncalcinated zinc oxide which is 98.48% and 96.31 % respectively at 150 minutes. The degradation kinetics conformed to the pseudo-first-order kinetic model. The present study showed that calcinated and uncalcinated zinc oxide ZnO can be effectively used as efficient photoc...

International Letters of Chemistry, Physics and Astronomy

The adsorption of methylene blue (MB) dye on bush cane bark powder has been studied by analyzing ... more The adsorption of methylene blue (MB) dye on bush cane bark powder has been studied by analyzing the effect of contact time, initial dye concentration, adsorbent dose, pH, and temperature on the amount of the MB dye adsorbed per unit mass of the bush cane bark powder adsorbent. An optimum adsorption could be achieved during 80 min contact time but, thereafter, decreased with contact time beyond 80 min. The adsorption of the methylene blue dye increased with increasing the initial dye concentration, temperature and pH. However, the amount of methylene blue adsorbed decreased with increasing the dosage of the adsorbent; a phenomenon attributed to a plausible agglomeration of the adsorbent and blocking of the preferred adsorption sites with increasing adsorbent dosage. The adsorption mechanism of the dye obeyed the Freundlich isotherm. Kinetic studies showed that the methylene blue adsorption onto bush cane bark powder adsorbent followed a second order reaction kinetics. The adsorbent ...

International Letters of Chemistry, Physics and Astronomy, 2017

The potential of white potato peel powder for the removal of methyl red (MR) dye from aqueous sol... more The potential of white potato peel powder for the removal of methyl red (MR) dye from aqueous solution was investigated. The adsorbent was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MR onto the adsorbent (WPPP) was found to be contact (80 mins), pH (2) and temperature (303K) for an initial MR dye concentration of 50mg/l and adsorbent dose of 1.0g. The experimental equilibrium adsorption data of the (MR) dye fitted best and well to the Freundlich isotherm model. The maximum adsorption capacity was found to be 30.48mg/g for the adsorption of MR. The kinetic data conforms to the pseudo – second order kinetic model.

International Letters of Natural Sciences, 2016

In order to estimate plant available fraction of metals in two soil samples-contaminated soil (A)... more In order to estimate plant available fraction of metals in two soil samples-contaminated soil (A) and non-contaminated soil (B), a vegetable crop,Curcubita ficifoliawas grown on both soil samples. The matured leaf was harvested and analyzed for its metal concentration after three (3) months of growth. The soil samples were collected before and after planting, digested with acid and analyzed to determine the pseudo total metal concentration and quantification was done using atomic absorption spectroscopy (AAS). To correlate metal accumulation by the vegetable with potential bioavailability of metals in soils, sequential extraction (SE) using the modified BCR technique was performed on the soils. Soil sample B was used for quality control. It was observed that each metal differed considerably in uptake. And theC. ficifoliacultivated on soil sample A had tissue concentrations of Zn, Mn and Cu as follows: 39.6mgkg-1, 18.3mgkg-1and 26.3mgkg-1respectively. Also,C. ficifoliacultivated on s...

International Letters of Chemistry, Physics and Astronomy, 2016

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red... more The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22...

IOSR Journal of Applied Chemistry, 2016

The removal of Crystal Violet (CV) dye with the powder of picrilima nitida stem bark (PNSBP) has ... more The removal of Crystal Violet (CV) dye with the powder of picrilima nitida stem bark (PNSBP) has been demonstrated based on adsorption parameters like contact time, initial dye concentration, adsorbent dose, pH, and temperature. The adsorbent was characterized by FTIR and SEM analysis. Equilibrium amount of CV dye adsorbed per unit mass of PNSBP adsorbent, qe (mg/g), occurred after 60 min. contact time. The q e values increased with increasing initial CV dye concentration from 25 mg/L to 125 mg/L, and with pH increasing from 2 to 10. However, the q e value continuously decreased as temperature increased from 30 o C to 70 o C and PNSBP adsorbent dosage from 0.5 g to 4 g. Based on values of correlation coefficient (R 2), the Freundlich isotherm was more appropriate in explaining the mechanism of the CV adsorption onto PNSB. Kinetic studies showed that the CV dye adsorption onto PNSB adsorbent followed the pseudo second order reaction kinetics. Thermodynamic quantities were evaluated and the negative G 0 values obtained indicated spontaneous adsorption process. The negative H 0 and S 0 values obtained indicate the exothermic nature and decrease in randomness during the adsorption process respectively.

IOSR Journal of Applied Chemistry, 2016

The potential of almond seed shell (ASSP), for the removal of methyl violet (MV) dye from aqueous... more The potential of almond seed shell (ASSP), for the removal of methyl violet (MV) dye from aqueous solution was investigated. The adsorbent was characterized by SEM and FTIR analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MV onto the adsorbent (ASSP) was found to be: contact time (80 mins), pH (10.0) and temperature (303 K) for an initial MV dye concentration of 50 mg/L with adsorbent dose of 1.0 g. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for the dye adsorption. The maximum adsorption capacity was found to be 628.93 mg/g for the adsorption of MV dye. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (G 0), enthalpy (H 0) and entropy (S 0) were evaluated and the negative values of G 0 obtained indicated the spontaneous nature of the adsorption processes. The negative H 0 and positive values of S 0 indicate the exothermic nature and increased randomness during the adsorption of MV onto ASSP.

Journal of Radioanalytical and Nuclear Chemistry, 2013

Radionuclide adsorption on clay rocks has in recent years been studied mainly in connection with ... more Radionuclide adsorption on clay rocks has in recent years been studied mainly in connection with their use as sealing barriers in nuclear waste and spent nuclear fuel repositories. In Slovakia we find deposits of bentonites which should be used for the above mentioned purpose. The usability of adsorbents in practical applications depends on the speed of the adsorption process of the adsorbate on the adsorbent surface and distribution ratio. The work objective was the study of the kinetics of Sr adsorption on clay adsorbents with different geological origin. The geological origin of bentonite significantly influences its mineralogical and chemical composition and therein its adsorption properties. The adsorption process of strontium was fast. Adsorption equilibrium was reached for all three samples studied within 1 min from the beginning of the contact between solid and liquid phases. After the adsorption equilibrium was reached there were no more changes in the values of distribution coefficients and the adsorption percentage, and comparable values were reached in the contact-phase time span studied within 10 days. The values of adsorbed strontium were decreasing in the following order: J250 [ L250 [ DV45. The pseudo second-order kinetic models was used to describe model the kinetic data and provided excellent kinetic data fitting (R 2 [ 0.999).

Environmental Progress & Sustainable Energy, 2013

In this work, a continuous fixed-bed adsorption study was carried out by using NaOH-modified rice... more In this work, a continuous fixed-bed adsorption study was carried out by using NaOH-modified rice husk (NMRH) as an adsorbent for the removal of malachite green (MG) from its aqueous solution. The influence of important process parameters such as initial solution pH, influent concentration of MG, feed flow rate, and bed height on breakthrough curve and breakthrough time was investigated. The breakthrough time increased with decreasing flow rate. The same effect was noted when the bed height was increased. On the other hand, the breakthrough time decreased as the inlet dye concentration was increased keeping the flow rate and bed height constant. Four different kinetic models, namely Adams-Bohart, bed depth service time bed depth service time (BDST), Thomas model, and Yoon-Nelson model were fitted to the experimental data. The Thomas model showed best fit at all experimental conditions studied. Overall, this study showed that NMRH has potential for technological application as adsorbent in dye wastewater treatment. 2012 Ameri

International Letters of Chemistry, Physics and Astronomy, 2016

Dextrin produced from cassava was investigated for adsorption on coal during processing. Aluminiu... more Dextrin produced from cassava was investigated for adsorption on coal during processing. Aluminium ion (Al3+) and nitrate ion (NO3-) were employed for adsorption test to improve coal surfaces. The effect of initial concentration, adsorbent dose and pH on dextrin adsorption onto modified coal surface was investigated. Studies concerning the adsorption equilibrium and thermodynamics are presented; the equilibrium data was modelled using Langmuir and Freundlich isotherms. The adsorption equilibrium data was well explained by Freundlich isotherm. The percentage removal was found to be 93.75% and 90.75% at adsorbent dose of 0.2 g for both aluminium sulphate coal bituminous (ACB) and aluminium sulphate coal lignite (ACL) respectively. There was a rapid increase in adsorption of dextrin from low pH of 2 to about pH of 4 with a plateau region from pH 4 to pH 6. Adsorption capacity of 61.25 mg/g and 55.00 mg/g was achieved at initial concentration of 200 mg/L for ACB and ACL respectively. Fo...