Adsorption Studies

Biosorption of Pb2+ and Zn2+ onto Phosphoric Acid Modified Rice Husk (PAMRH) was carried out. The equilibrium adsorption data of Pb2+ and Zn2+ for initial concentration ranging from 10 – 200 mg g-1 were fitted into Langmuir, Freundlich, Temkin, Dubinin-Raduskevich, Jovanovic, Flory-Huggins, FowlerGuggenheim and Kiselev isotherm models. The comparative isotherm studies however, unraveled the adsorption capacities of PAMRH and a great affinity of the adsorbent (PAMRH) for Pb2+ than Zn2+. The studies showed that the adsorption Modeling of Biosorption of Pb(Ii) and Zn(Ii) Ions onto Pamrh: Langmuir, Freundlich, Temkin, Dubinin-Raduskevich, Jovanovic, Flory-Huggins, Fowler-Guggenheim and Kiselev Comparative Isotherm Studies http://www.iaeme.com/IJMET/index.asp 1049 editor@iaeme.com capacities obtained from isotherm models for Pb2+ are relatively higher than that of Zn2+. Comparatively, based on the correlation coefficients (R2) obtained from both Pb2+ and Zn2+ linear plots, the equilibriu...

This study investigates the potential uses of palm shell, pretreated with sulfuric acid (APSP) for the adsorption of AOII, DSB, and AV7. The effects of different system variables like adsorbent dosage, pH, contact time, and temperature were studied. Optimum pH values for all the three dyes were determined as 1.0. Equilibrium was achieved within 30 min. Langmuir I, II, III, IV and Freundlich isotherm models were applied to describe the equilibrium isotherms at different temperatures, and the langmuir model was found to agree very well with the experimental data. The maximum adsorption capacity was found to be 2180.05 mg/g, 1199.99 mg/g, and 243.9 mg/g for AOII, DSB, and AV7, respectively. Thermodynamic parameters such as change in free energy (∆G0), enthalpy (∆H0), and entropy (∆S0) were also determined. Pseudo-first-order, pseudo-second order, and intraparticle diffusion models were used to fit the experimental data. The pseudo-second-order equation was able to fit well and provide a realistic description of the adsorption kinetics.

Adsorption of indigo dye onto rice bran has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the lowcost adsorbent for the removal of the dye. The influence of contact time, pH, temperature, adsorbate concentration and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly with the aforementioned parameters. The values; 40 minutes, 3.0, 0.3g, 40 mgL-1 , and 55 0 C gave the optimum contact time, pH, adsorbent dosage, adsorbate concentration and temperature, respectively. The adsorption isotherm was well fitted by the Dubinin-R model with R 2 as high as 0.95. The sorption energy of 0.7kJmol-1 obtained from the Dubinin-R isotherm reveals that physisorption was the dominant adsorption mechanism. Results indicate that the freely abundant, locally available, low-cost adsorbent, rice bran can be treated as economically viable for the removal of indigo dye from industrial effluents.

Studies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies ...

The adsorption potential of raw pomegranate peel powder (PMPP) for lead (Pb) ions was investigated via batch mode at varying initial adsorbate concentration, contact time, and adsorbent concentration. The PMPP was extensively characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersion X-ray (EDX), thermogravimetry (TG), and differential scanning calorimetry (DSC) analyses. The instrumental characterization results confirmed the presence of important functional groups and surface texture/morphology that played key roles during the lead ion adsorption. Description of the experimental equilibrium data by nonlinear Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models was elaborately presented in the study. The experimental kinetic data were fitted to the Pseudo-first-order, Pseudo-second-order, Intra-particle diffusion, and Elovich models. The Temkin model satisfactorily predicted the isotherm data. Meanwhile, the intra-particle diffusion model was best at predicting the kinetic data at adsorbate concentration of 150 mg/L, while the Elovich model emerged as the best fit at 300 mg/L concentration. This study shows that lead ions could be efficiently removed using raw pomegranate peel powder.

Objective: The discharge of these synthetic food dyes, such as sunset yellow and tartrazine, into industrial wastewater can lead to significant environmental and health issues. Its removal through effective adsorption presents an economical and efficient solution. Hence this study proposed to fabricate metal nanoparticles for the adsorption of carcinogenic dyes. Methods: The fabrication of iron and zinc nanoparticles employed the green synthesis methodology, utilizing an aqueous extract of Diospyros chloroxylon (Roxb.) as a reducing agent. The fabricated nanoparticles were characterized using TEM (Transmission Electron Microscopy), EDX (Energy-Dispersive X-ray Spectroscopy), SEM (Scanning Electron Microscopy), FTIR (Fourier-Transform Infrared Spectroscopy), and UV-Visible Spectroscopy. The nanoparticles were studied for its efficiency for the adsorption of carcinogenic dyes such as tartrazine and Sunset Yellow. Results: The iron nanoparticles were noticed to be uniformly distributed rod-shaped particles having smooth surfaces with 23-51 nm size range and an average particle size of 34 nm. Whereas the iron nanoparticles were noticed to be uniformly distributed spherical to o val shape with 35 nm to 68 nm size range and an average particle size 53 nm. The XRD results confirm that the iron nanoparticles were rhombohedral phase structure with 71.91 % of elemental iron whereas the zinc nanoparticles were noticed to be hexagonal Wurtzite phase structure having 69.4 % of metallic zinc. These synthesized nanoparticles were applied for the removal of sunset yellow and tartrazine dyes were investigated and found more than 90 % was removed. Adsorption isotherm study was best fitted with Langmuir model, and the maximal adsorption capacity was found to be 52.18 and 75.04 mg/g for sunset yellow using iron and zinc nanoparticles, whereas tartrazine maximum adsorption capacity was noticed to be 69.96 and 84.24 mg/g for iron and zinc nanoparticles. The adsorption reaction follows pseudo-first-order kinetics with high correlation coefficient. Repeated cycles of regeneration, reuse and stability showed very high removal efficiency and stability. Conclusion: The biosynthesis of metal nanoparticles demonstrates substantial promise for applications in environmental protection.

Adsorption of indigo dye onto rice bran has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the lowcost adsorbent for the removal of the dye. The influence of contact time, pH, temperature, adsorbate concentration and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly with the aforementioned parameters. The values; 40 minutes, 3.0, 0.3g, 40 mgL-1 , and 55 0 C gave the optimum contact time, pH, adsorbent dosage, adsorbate concentration and temperature, respectively. The adsorption isotherm was well fitted by the Dubinin-R model with R 2 as high as 0.95. The sorption energy of 0.7kJmol-1 obtained from the Dubinin-R isotherm reveals that physisorption was the dominant adsorption mechanism. Results indicate that the freely abundant, locally available, low-cost adsorbent, rice bran can be treated as economically viable for the removal of indigo dye from industrial effluents.

The feasibility of using medicinal plants species Retama raetam as a low cost and an eco-friendly adsorbent for the adsorption of cationic dye methylene blue from simulated aqueous solution has been investigated. Adsorption kinetics of methylene blue onto Retama raetam plants was studied in a batch system. The effects of pH and contact time were examined. The methylene blue maximum adsorption occurred at pH 8 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. Adsorption modelling parameters for Freundlich and Langmuir isotherms were determined and, based on R 2 , various error distribution functions were evaluated as well. Adsorption isotherm was best described by non linear Freundlich isotherm model. Thermodynamic studies show that adsorption was spontaneous and exothermic. For determining the best-fi t-kinetic adsorption model, the experimental data were analyzed by using pseudo-fi rst-order, pseudo-second-order, pseudo-third-order, Esquivel, and Elovich models. Linear regressive and non-linear regressive method was used to obtain the relative parameters. The statistical functions were estimated to fi nd the suitable method that fi t better the experimental data. Both methods were appropriate for obtaining the parameters. The linear pseudo-second-order (type 9 and type 10) models were the best to fi t the equilibrium data. The present work showed that plant Retama raetam can be used as a low cost adsorbent for the removal of methylene blue from water.

Adsorption is kinetically time-dependence controlled retention/ release mobility as a natural phenomenon in base and applicable in industry or in science. It is well-studied and modulated by known Langmuir, Temkin, Freundlich, and other models to describe how it occurred and explains kinetic- thermodynamic material behaviour. Linear and/ or non- linear expressions may take place according to the theoretical base of these models to conclude the layer formation, uniformity besides reaction reversibility, and favourability from kinetic- thermodynamic principles. Coefficient of determination (R2) is a mean variation of data or a degree of proper or fitting as mostly used in kinetic and isotherm literatures. In adsorption investigations, experimental physical- chemical conditions and error sources are the main influenced factors, for example, at surface coverage (or inhibition efficiency) in corrosion treatments or adsorption capacity in pollution subject. Linearity variation will govern...

This study investigates the potential of eggshell powder as a waste adsorbent for the removal of methylene blue dye from an aqueous solution. Taguchi method was employed for experimental design, and the data were analyzed using the signal-to-noise (S/N) ratio for the removal of methylene blue dye from aqueous solutions. During the removal process, a batch technique was used to determine the effects of several controllable factors on the percent of removal. These factors were pH of the solution (3, 6, 9 and 12), initial dye concentration (100, 150, 200 and 250 ppm), and adsorbent dose (0.25, 0.5, 0.75 and 1 g). The results revealed that the optimum conditions for methylene blue removal of about 70% were obtained at an adsorbent dose of 1 g, pH 9 and 100 ppm dye concentration for a contact time of about 1 hour and at agitation speed of 250 rpm. The effect of contact time was studied on the percent of removal from aqueous solution by eggshell powder. It was found that the rates of adsorption were rapid initially within the first 20 minutes and reached maximum adsorption after 1 hour. Analyses of results were achieved to discuss the contribution of the individual factors on the objective functions. Various adsorption isotherm models were investigated such as Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Harkins-Henderson. Kinetic studies were conducted on the adsorption of dye on eggshell powder. These kinetic models were the zero-order, pseudo-first order, pseudo-second-order, intra-particle diffusion, and Elovich models.

Biosorption of Pb2+ and Zn2+ onto Phosphoric Acid Modified Rice Husk (PAMRH) was carried out. The equilibrium adsorption data of Pb2+ and Zn2+ for initial concentration ranging from 10 – 200 mg g-1 were fitted into Langmuir, Freundlich, Temkin, Dubinin-Raduskevich, Jovanovic, Flory-Huggins, FowlerGuggenheim and Kiselev isotherm models. The comparative isotherm studies however, unraveled the adsorption capacities of PAMRH and a great affinity of the adsorbent (PAMRH) for Pb2+ than Zn2+. The studies showed that the adsorption Modeling of Biosorption of Pb(Ii) and Zn(Ii) Ions onto Pamrh: Langmuir, Freundlich, Temkin, Dubinin-Raduskevich, Jovanovic, Flory-Huggins, Fowler-Guggenheim and Kiselev Comparative Isotherm Studies http://www.iaeme.com/IJMET/index.asp 1049 editor@iaeme.com capacities obtained from isotherm models for Pb2+ are relatively higher than that of Zn2+. Comparatively, based on the correlation coefficients (R2) obtained from both Pb2+ and Zn2+ linear plots, the equilibriu...

The feasibility of using medicinal plants species Retama raetam as a low cost and an eco-friendly adsorbent for the adsorption of cationic dye methylene blue from simulated aqueous solution has been investigated. Adsorption kinetics of methylene blue onto Retama raetam plants was studied in a batch system. The effects of pH and contact time were examined. The methylene blue maximum adsorption occurred at pH 8 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. Adsorption modelling parameters for Freundlich and Langmuir isotherms were determined and, based on R 2 , various error distribution functions were evaluated as well. Adsorption isotherm was best described by non linear Freundlich isotherm model. Thermodynamic studies show that adsorption was spontaneous and exothermic. For determining the best-fi t-kinetic adsorption model, the experimental data were analyzed by using pseudo-fi rst-order, pseudo-second-order, pseudo-third-order, Esquivel, and Elovich models. Linear regressive and non-linear regressive method was used to obtain the relative parameters. The statistical functions were estimated to fi nd the suitable method that fi t better the experimental data. Both methods were appropriate for obtaining the parameters. The linear pseudo-second-order (type 9 and type 10) models were the best to fi t the equilibrium data. The present work showed that plant Retama raetam can be used as a low cost adsorbent for the removal of methylene blue from water.

The menace of corrosion of steel in industries has been widely acknowledged. Analysis of oil pipeline failures in oil and gas industries in the Niger Delta area of Nigeria showed corrosion as one of the major causes of failure. Eco-friendly, cheap and renewable materials such as plant extracts have been investigated as alternative to the use of expensive synthetic chemicals which are often hazardous. In this study inhibitive properties of ethanol extracts of Ficus polita and Ficus platyphylla leaves as eco-friendly inhibitors of mild steel in 2 M sulfuric acid solution were investigated by weight loss method at temperatures of 301, 305, 309 and 313 K. The study has shown that both plant extracts inhibited the corrosion of mild steel in the acid medium. The inhibition efficiency (IE) and surface coverage (θ) for both extracts increased with increase in concentration and temperature. This trend is suggestive of chemical adsorption. However, the leaf extract of Ficus polita showed high...

The adsorption of levafix red (LR) dye from waste water via batch adsorption onto treated jute stick powder was investigated. Studies concerning the factors influencing the adsorption such as adsorbent dosage, pH, contact time and temperature were systematically investigated and discussed. The results revealed that the maximum removal of levafix red was ~91% from water. The kinetics data were analyzed using pseudo-first order and pseudo-second order models. It was best described by the pseudo-second order model. The adsorption equilibrium follows Langmuir isotherm. This result indicates that treated jute stick powder could be employed as low-cost alternatives to commercial activated carbon for the removal of levafix red (LR) from waste water. Rapid industrialization in Bangladesh has resulted in increased water pollution that has higher dye level. Waste water from dyeing and finishing factories is a significant source of environmental pollution. The waste water is typically characte...

Adsorption is kinetically time-dependence controlled retention/ release mobility as a natural phenomenon in base and applicable in industry or in science. It is well-studied and modulated by known Langmuir, Temkin, Freundlich, and other models to describe how it occurred and explains kinetic-thermodynamic material behaviour. Linear and/ or non-linear expressions may take place according to the theoretical base of these models to conclude the layer formation, uniformity besides reaction reversibility, and favourability from kinetic-thermodynamic principles. Coefficient of determination (R 2) is a mean variation of data or a degree of proper or fitting as mostly used in kinetic and isotherm literatures. In adsorption investigations, experimental physical-chemical conditions and error sources are the main influenced factors, for example, at surface coverage (or inhibition efficiency) in corrosion treatments or adsorption capacity in pollution subject. Linearity variation will govern R 2 to predict adsorbate behaviour on adsorbent surface that is highly influenced by concentration, temperature, pH, type of measuring method, physical and chemical structures of the adsorbent and adsorbate, and error sources in each experiment.

The search for antimicrobial drug of high bio-efficacy not prone to multiple microbial resistance has been on the rise in recent time. This study focused on the preparation, characterization and antimicrobial evaluation of Schiff functionalized HNO3 activated plantain peel and rice husk biochar against five pathogenic bacteria. The activated rice husk and plantain peel biochar were characterized using Braunauer-Emmett-Teller, X-ray diffraction and Fourier transform infra-red spectroscopy. Based on the result, the activated rice husk and plantain peel biochar were amorphous and crystalline respectively with pore surface area and pore size for activated rice husk and plantain peel biochar as 9.369 and 27.32 (m2.g-1) and 8.790 and 16.65 (cc.g-1), respectively. The Fourier transform infra-red spectroscopy result indicated bonds, such as –OH, C=O and –N-H, where actual chelation and electrostatic attraction mechanism are prevalent responsible for antimicrobial potency. The cell bioactivi...

Adsorption phenomenon is a popular separation process in environmental remediation and wastewater treatment due to its simplicity, low cost, efficiency, and environmentally friendliness. The amount of material absorbed by a substrate is often expressed as a function of the equilibrium concentration at a constant temperature in a process known as Adsorption Isotherm. The study of adsorption isotherms is essential to gain insight into the design and operation of adsorption systems. In this review paper, the general knowledge and application of the isotherm model to date have been highlighted for an insight into the concept and application of adsorption isotherm models. The classification of the isotherm model has also been highlighted. In addition, various types of isotherm models in terms of the number of parameters have been extensively discussed. The criteria for selecting the appropriate model as well as the modern trend in the modelling approach have also been discussed. This review will enable researcher make informed choices in selecting adsorption isotherm models.

Although the benefits of applying biochar for the purposes of soil conditioning and crop productivity enhancement have been demonstrated, relatively few studies have elaborated on its causal mechanisms, especially on the biochar-fertilizer interaction. Thus, in the present study, the ex-situ adsorptive potential of base activated biochar (BAB) towards plant nutrient immobilization and removal from aqueous solutions was investigated. Napier grass (Pennisetum purpureum) was utilized as the precursor to prepare slow vacuum pyrolysed char and its affinity towards adsorption of urea was examined at various process conditions. Low sorption temperatures, moderate agitation speeds and high initial concentration were seen to favour greater urea uptake by BAB. The sorption was exothermic, physical, spontaneous and had a pseudo-second order kinetic fit. Both surface and intra-particle diffusion governed the removal and immobilization of urea. Furthermore, process mass transfer was limited by film diffusion of urea to the external surface of the BAB. Equilibrium studies suggested that Dubinin-Radushkevich is the most appropriate model to describe the urea-BAB behaviour with maximum uptake, estimated to be 1115 mg•g −1. Through such ex-situ analysis, it could be possible to have prior knowledge, quantification and differentiation of the potential of chars manufactured from various feedstocks. This could then be used as an effective screening step in designing appropriate biochar-fertilizer systems for soil conditioning and help reduce the time and effort spent otherwise in long-term field studies.

The adsorption equilibrium isotherms of oil content via the electrocoagulation treatment of real oily wastewater were studied and modeled. Ten isotherm models (Langmuir, Freundlish, Temkin, Dubinin-Radushkevich, Kiselev, Fowler-Guggenheim, Elovich, Hurkins-Jura, Jovanovic and Hill-de Boer models) were selected to predict the adsorption equilibrium isotherms and their characteristics parameters. A triple aluminum tubes was manufactured in a monopolarconcentric arrangement to investigate the purpose of treating real oily wastewater (523.11 ppm of oil content) produced from crude oil wells location (West Qurna 1 /Basra-Iraq) under the impacts of the operational variables; the electrolysis time (2-20 min.), the current density (4.4 mA/cm 2), the initial pH equaling 6.5, and the agitation speed fixed as 200 rpm. The results showed that the studied models fitted the data in the order as: Freundlish (R 2 =0.9991) > Langmuir (R 2 =0.9960) > Hurkins-Jura (R 2 =0.9926) > Temkin (R 2 =0.9922) > Elovich (R 2 =0.9906) > Jovanovic (R 2 =0.9573) > Fowler-Guggenheim (R 2 =0.8676) > Hill-de Boer (R 2 =0.8294) > Dubinin-Radushkevich (R 2 =0.7928) > Kiselev (R 2 =0.7366) isotherms. The modeling of adsorption isotherm revealed that the interaction of oil content with the electrocoagulant is characterized as physical adsorption process. There is no formation of complex between the adsorbed molecules due to the repulsion among them. Additionally, the heat of adsorption will decrease with loading via the electrocoagulation treatment of real oily wastewater.

Nitrosonaphthol dyes and other corresponding analogues were synthesised from 1-Naphthol. The dyes were applied onto chrome and vegetable tanned leather upon characterization. The results indicate that the dye bath exhaustion was better on chrome tanned leather than on vegetable tanned leather. This may be attributed to the chelating effect of chrome on leather and the higher temperature of dyeing the chrome tanned leather compared with the vegetable tanned leather. The fastness properties of the dyes of washing ranging from (3-5), perspiration on acid (4-5), alkaline (4-5) and light (4-7) were impressive on both vegetable and chrome tanned leather respectively.

Studies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies ...

The search for antimicrobial drug of high bio-efficacy not prone to multiple microbial resistance has been on the rise in recent time. This study focused on the preparation, characterization and antimicrobial evaluation of Schiff functionalized HNO3 activated plantain peel and rice husk biochar against five pathogenic bacteria. The activated rice husk and plantain peel biochar were characterized using Braunauer-Emmett-Teller, X-ray diffraction and Fourier transform infra-red spectroscopy. Based on the result, the activated rice husk and plantain peel biochar were amorphous and crystalline respectively with pore surface area and pore size for activated rice husk and plantain peel biochar as 9.369 and 27.32 (m2.g-1) and 8.790 and 16.65 (cc.g-1), respectively. The Fourier transform infra-red spectroscopy result indicated bonds, such as –OH, C=O and –N-H, where actual chelation and electrostatic attraction mechanism are prevalent responsible for antimicrobial potency. The cell bioactivi...

In this work, removal of Eosin Yellow (EY) using Natural Goethite (NGT) and Synthetic Goethite (SGT) particles was studied using batch equilibrium technique. Different parameters such as initial dye concentration, particle size (NGT only), pH, and adsorbent dose were optimized to investigate the sorbents efficiency for the dye. The experimental data were tested for fitness into five common adsorption isotherm models. The various equilibrium parameters studied were found to have remarkable influence on the adsorption processes, showing optimum removal at dye concentration (150 mg/L for EY-NGT and 200 mg/L for EY-SGT), NGT particle size (0.112mm), pH (2), and dosage (0.05g), with SGT exhibiting relatively higher adsorption efficiency. The sorption data fitted well the various isotherm models in the order; Freundlich (R2 = 0.9032) > Temkin (0.8294) > Langmuir (0.8268) > DKR (0.6431) > Flory Huggins (0.616) for EY-NGT, and Langmuir (0.9831) > Flory Huggins (0.9639) > F...

Stinging nettle was used as lignocellulosic adsorbent for the removal of cationic dye – malachite green (MG), and anionic dye – Congo red (CR), from aqueous solution, without any chemical pretreatment. The adsorption equilibrium data fitted well with the Langmuir model for the adsorption of both dyes, with the calculated maximum adsorption capacity of 270.27 mgg and 172.14 mgg for MG and CR, respectively. The adsorption process was controlled by the pseudo-second-order model in the adsorption of MG and by the pseudo-first-order model in the adsorption of CR. The thermodynamics modelling displayed that the process was spontaneous and endothermic. The π–π electron–donor interaction, hydrogen bonds and pore diffusion may also be effective, besides electrostatic interaction between the adsorbate and the adsorbent in the mechanism of MG and CR uptake.

The menace of corrosion of steel in industries has been widely acknowledged. Analysis of oil pipeline failures in oil and gas industries in the Niger Delta area of Nigeria showed corrosion as one of the major causes of failure. Eco-friendly, cheap and renewable materials such as plant extracts have been investigated as alternative to the use of expensive synthetic chemicals which are often hazardous. In this study inhibitive properties of ethanol extracts of Ficus polita and Ficus platyphylla leaves as eco-friendly inhibitors of mild steel in 2 M sulfuric acid solution were investigated by weight loss method at temperatures of 301, 305, 309 and 313 K. The study has shown that both plant extracts inhibited the corrosion of mild steel in the acid medium. The inhibition efficiency (IE) and surface coverage (θ) for both extracts increased with increase in concentration and temperature. This trend is suggestive of chemical adsorption. However, the leaf extract of Ficus polita showed high...

Corrosion inhibition characteristics of aspartic acid on  mild steel corrosion in 0.5 M H2SO4 was investigated using weight loss, acidimetry, and electrochemical impedance spectroscopy (EIS). Analysis of the metal surface morphology, uninhibited and inhibited, was carried out through scanned electron microscope. The results showed that the inhibition efficiency increased with increase in inhibitors concentration and rise in temperature for all methods used. The highest v efficiency of  32.36 %, 66.26 % and 80.40 % were obtained for weight loss, acidimetry and EIS, respectively. The low value of efficiency for weight loss compared to other methods should signify the limitation for the method. The increase in efficiency with rise in temperature is a feature of chemical adsorption, which was confoirmed by the value of parameter b of the Adejo-Ekwenchi adsorption isotherm (AEI) model. Values of free energy of adsorption, ?Gads were all negative for all the methods, which means the adsor...

The study evaluated the adsorption potential of white cedar sawdust (WCS) for dye removal. WCS was chosen from five preferred, abundant waste biomasses from Pakistan. Various parameters such as contact time, adsorbent dose, dye concentration, pH, and particle size were optimized for methylene blue (MB) dye adsorption. The adsorbent was characterized by FTIR, SEM, EDX and BET analyses. The surface area of the adsorbent was 1.43 m 2 •g-1 and pore volume was 0.000687 cm 3 •g-1. The adsorption data best fitted the isotherm models of Langmuir, Temkin, Dubinin-Radushkevich, and Freundlich. The maximum experimental adsorption capacity obtained was 55.15 mg•g-1 , which was in close agreement to the calculated adsorption capacity. Fitness of the pseudo-second order kinetics suggested chemisorption as the rate-limiting step. Thermodynamic study for adsorption was carried out to evaluate the Gibbs free energy (∆G°), enthalpy (∆H°) and entropy (∆S°). The negative values ΔG° at the examined temperature range confirmed the spontaneous adsorption of MB onto WCS.

Stinging nettle was used as lignocellulosic adsorbent for the removal of cationic dye – malachite green (MG), and anionic dye – Congo red (CR), from aqueous solution, without any chemical pretreatment. The adsorption equilibrium data fitted well with the Langmuir model for the adsorption of both dyes, with the calculated maximum adsorption capacity of 270.27 mgg-1 and 172.14 mgg-1 for MG and CR, respectively. The adsorption process was controlled by the pseudo-second-order model in the adsorption of MG and by the pseudo-first-order model in the adsorption of CR. The thermodynamics modelling displayed that the process was spontaneous and endothermic. The π–π electron–donor interaction, hydrogen bonds and pore diffusion may also be effective, besides electrostatic interaction between the adsorbate and the adsorbent in the mechanism of MG and CR uptake.

Although the benefits of applying biochar for the purposes of soil conditioning and crop productivity enhancement have been demonstrated, relatively few studies have elaborated on its causal mechanisms, especially on the biochar-fertilizer interaction. Thus, in the present study, the ex-situ adsorptive potential of base activated biochar (BAB) towards plant nutrient immobilization and removal from aqueous solutions was investigated. Napier grass (Pennisetum purpureum) was utilized as the precursor to prepare slow vacuum pyrolysed char and its affinity towards adsorption of urea was examined at various process conditions. Low sorption temperatures, moderate agitation speeds and high initial concentration were seen to favour greater urea uptake by BAB. The sorption was exothermic, physical, spontaneous and had a pseudo-second order kinetic fit. Both surface and intra-particle diffusion governed the removal and immobilization of urea. Furthermore, process mass transfer was limited by film diffusion of urea to the external surface of the BAB. Equilibrium studies suggested that Dubinin-Radushkevich is the most appropriate model to describe the urea-BAB behaviour with maximum uptake, estimated to be 1115 mg•g −1. Through such ex-situ analysis, it could be possible to have prior knowledge, quantification and differentiation of the potential of chars manufactured from various feedstocks. This could then be used as an effective screening step in designing appropriate biochar-fertilizer systems for soil conditioning and help reduce the time and effort spent otherwise in long-term field studies.

Although the benefits of applying biochar for the purposes of soil conditioning and crop productivity enhancement have been demonstrated, relatively few studies have elaborated on its causal mechanisms, especially on the biochar-fertilizer interaction. Thus, in the present study, the ex-situ adsorptive potential of base activated biochar (BAB) towards plant nutrient immobilization and removal from aqueous solutions was investigated. Napier grass (Pennisetum purpureum) was utilized as the precursor to prepare slow vacuum pyrolysed char and its affinity towards adsorption of urea was examined at various process conditions. Low sorption temperatures, moderate agitation speeds and high initial concentration were seen to favour greater urea uptake by BAB. The sorption was exothermic, physical, spontaneous and had a pseudo-second order kinetic fit. Both surface and intra-particle diffusion governed the removal and immobilization of urea. Furthermore, process mass transfer was limited by film diffusion of urea to the external surface of the BAB. Equilibrium studies suggested that Dubinin-Radushkevich is the most appropriate model to describe the urea-BAB behaviour with maximum uptake, estimated to be 1115 mg•g −1. Through such ex-situ analysis, it could be possible to have prior knowledge, quantification and differentiation of the potential of chars manufactured from various feedstocks. This could then be used as an effective screening step in designing appropriate biochar-fertilizer systems for soil conditioning and help reduce the time and effort spent otherwise in long-term field studies.

The present paper is aimed to investigate and develop adsorption methods for colour removal from wastewater using waste material a non-carbon adsorbent Nano alumina (NA). The unique properties of Nano materials have promisingly exhibited in solving many environmental issues. The high surface area and unique adsorption capacity of NA were successfully utilized in removing water-soluble azo dye, Tropaeoline 000 from wastewater. Equilibrium isotherms for the adsorption of the dye were measured experimentally. Results were analysed by the Freundlich and Langmuir equation at different temperatures and determined characteristic parameters for each adsorption isotherm. Specific rate constants of the processes were calculated by kinetic measurements and pseudo-second-order adsorption kinetics was observed in each case. Thermodynamic parameters like free energy (DG), enthalpy (DH) and entropy (DS) of the systems were calculated by using Langmuir constant. The adsorption process followed pseudo-second-order model.

Many corrosion monitoring techniques are available to study the behaviour of inhibitors in various media. Common among these techniques are weight loss, gasometric, thermometric, acidimetric, electrochemical impedance spectroscopy and a host of others. Each of these techniques has its strengths and weaknesses. While some of them are quite prone to errors, others require, extremely, expensive instrumentation. The acidimetric technique is, however, the least applied of among these techniques, in spite of its obvious advantages of simplicity, less prone to error and inexpensiveness. In this research work, we applied the acidimetric technique to the study of corrosion inhibition of mild steel in H 2 SO 4 medium using urea, an organic molecule, as an inhibitor. The efficacy of the technique was then compared with an established and commonly applied corrosion monitoring technique; the weight loss technique. The two techniques were found out to give quite comparable results. However, the acidimetric technique was found to be faster, simpler, and yielded comparatively better results. The inhibition efficiency, %IE, which has the same trend for the two methods, decreased with increase in temperature, suggestive of physisorption. This was collaborated by values of activation energy, E a , which are all below 80 kJ/mol. The adsorption mechanism of urea adsorption onto the metal surface was, therefore, resolved with the use of Adejo-Ekwenchi isotherm adsorption model to be physisorption, with the best fit adsorption isotherms being the Langmuir and El-Awady isotherm models.

The resolution of ambiguity usually associated with the characterisation of adsorption process of the plant extracts as corrosion inhibitors for metal corrosion was achieved through the use of Adejo-Ekwenchi adsorption isotherm using the case of corrosion inhibition of mild steel corrosion in 2 M HCl by ethanol leaf extract of Hyptis suaveolens poit. The study was carried out using the weight loss method at the temperature range of 301 K to 313 K. The inhibition efficiency, %IE, was found to decrease with increase in temperature, suggestive of physical adsorption (physisorption) mechanism. The observed decrease in the value of parameter b of the Adejo-Ekwenchi isotherm is a confirmation of a physisorption for adsorption of this extract onto the metal surface. By the use of R2 and ?Gads this adsorption would be thought to well fit into Langmuir, Freundlich, Temkin and El-Awady. But the adsorption process best fit the Langmuir isotherm, as resolved through the Adejo-Ekwenchi isotherm....

Thermodynamic, kinetic and adsorptive parameters of methanolic extract of leaves of Cochlospermum tinctorium as eco-friendly inhibitor for the corrosion of mild steel in HCl medium were evaluated through the weight loss method at 303 K and 311 K. The inhibition efficiency, %IE, increased with increase in extract concentration, but found to be better at 303 K than 311 K. The decrease in %IE with increase in temperature with the average value of 81.88 kJ/mol for activation energy, E a , and the values of free energy, ÄG, for the adsorption process are all supportive of physical adsorption mechanism. The values of heat of adsorption, Q ads,, are all negative, an indication that the adsorption process was exothermal. The half-life, t 1/2 , value increased with increase in inhibitor concentration and low at high higher, implying the inhibitor performance increased with increase in the extract concentration and decreased with rise in temperature. The data best fitted the Langmuir adsorpti...

The feasibility of using medicinal plants species Retama raetam as a low cost and an eco-friendly adsorbent for the adsorption of cationic dye methylene blue from simulated aqueous solution has been investigated. Adsorption kinetics of methylene blue onto Retama raetam plants was studied in a batch system. The effects of pH and contact time were examined. The methylene blue maximum adsorption occurred at pH 8 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. Adsorption modelling parameters for Freundlich and Langmuir isotherms were determined and, based on R 2 , various error distribution functions were evaluated as well. Adsorption isotherm was best described by non linear Freundlich isotherm model. Thermodynamic studies show that adsorption was spontaneous and exothermic. For determining the best-fi t-kinetic adsorption model, the experimental data were analyzed by using pseudo-fi rst-or...

Rice husk has a high silica content, so it can be utilized as silica source for zeolite synthesis. In this research, synthesis of zeolite L has been done using silica from rice husk ash without organic template. The synthesized zeolite L is then used as an adsorbent to adsorb methylene blue dye. The steps of zeolite L synthesis include: silica extraction from rice husk ash using NaOH and zeolite L synthesis using hydrothermal method with molar ratio 10 SiO2: Al2O3: 4 K2O: 100 H2O at 170°C for 24 hours. The resulting Zeolite L was then characterized by XRD and SEM. The absorption capacity of methylene blue solution by zeolite L was observed experimentally through the effect of pH of the solution, contact time, and initial concentration of the solution, then determining the isotherm and its absorption kinetics. From XRD and SEM results of zeolite L sample, it is shown that zeolite L has been formed and its particle morphology is a hollow cylinder with cylinder diameter of 0.049 - 0.12...

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The search for antimicrobial drug of high bio-efficacy not prone to multiple microbial resistance has been on the rise in recent time. This study focused on the preparation, characterization and antimicrobial evaluation of Schiff functionalized HNO 3 activated plantain peel and rice husk biochar against five pathogenic bacteria. The activated rice husk and plantain peel biochar were characterized using Braunauer-Emmett-Teller, X-ray diffraction and Fourier transform infra-red spectroscopy. Based on the result, the activated rice husk and plantain peel biochar were amorphous and crystalline respectively with pore surface area and pore size for activated rice husk and plantain peel biochar as 9.369 and 27.32 (m 2 .g-1) and 8.790 and 16.65 (cc.g-1), respectively. The Fourier transform infra-red spectroscopy result indicated bonds, such as-OH, C=O and-N-H, where actual chelation and electrostatic attraction mechanism are prevalent responsible for antimicrobial potency. The cell bioactivity was hampered due to permeation of the biocidal agents, cell membrane disruption and generation of reactive oxygen species enhanced by conjugation of Schiff base based biochar to the microbial cell wall leading to death of microbes. The ease of Schiff base release and reusability of the nanocomposite favors the product as an efficient, low cost, effective and promising nanocomposite for decontamination of bacteria infested media.

Removal efficiency of methylene blue (MEB) from aqueous media was studied under different experimental conditions of pH, contact time and initial concentration of the adsorbate. Activated rice husk biochar (ARHB) was characterized using BET surface area and XRD. The XRD diffraction indicated amorphous nature of the biochar with pore size (cc/g) and pore surface area (m2/g) of 9.369 and 27.32 respectively from BET surface area plot. Equilibrium isotherm based on coefficient of non-determination indicated the following order as best fit model: Hill ˃ Kiselev ˃Elovic ˃Flory-Huggins > Langmuir > Jovanovic > Harkin-Jura >Freundlich > Henry > Temkin >Redlich Peterson>Durbinin-Kaganer Redushkevich >Hill-de Boer > Fowler-Guggenheim. Based on the highest correlation coefficient and the lowest values of the error functions applied to the kinetic models, Weber and Morris intra-particle diffusion and liquid film diffusion were noted to be in control of the sorption rate. The MEB sorption capacity of the activated biochar was 356.99 mmolkg-1 which was in the range of commercially available activated carbons and other biosorbents.

Studies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m 2 /g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating lead (II) ions contaminated environment. 1.0. Introduction: The indiscriminate discharge of heavy metals such as zinc, lead, cadmium through anthropogenic means into the environment has been reported as the major cause of water and soil pollution [1-3]. The presence of heavy metals on the environment is of global concern due to possible adverse effects on human health, as well as aquatic flora and fauna. A direct or secondary disposal heavy metal such as lead to soils and waters poses significant environmental risks, as they are non-degraded and, in high concentrations, are also very toxic [4]. It has been implicated among the most common global pollutants. This increasing rise in the concentration of lead on the environment is as a result of increasing population and anthropogenic activities in the developing nations. Its assimilation in relatively small amounts over a long period of time in the human body can lead to the malfunctioning of the organs and chronic toxicity. It has also been implicated as a major cause of miscarriages and deaths often experienced in mineral rich areas [5]. Lead is commonly present in effluents due to its wide industrial applications such as in mining, refineries, painting, metal plating and cleaning, battery and car radiator manufacturing and agricultural activities [6]. The removal of this toxic heavy metal is no doubt a worthwhile venture that should draw the attention of researchers and relevant government agencies. Biochar is a carbon rich, solid by-product resulting from the pyrolysis of biomass under oxygen-free and low temperature conditions. Biochar's proven ability to remain stable against chemical and biological degradation, when applied to soils, makes it a pioneer means of mitigating climate change [4]. Biochar from plantain peels have been proven to exert effects on clinically important agents and are important as good adsorbent [7]. The indiscriminate disposal of plantain peels constitute serious environmental hazard as it oftentimes leads to clogging of waterways causing flooding and also converting the town centers to foul smelling scenes. Peels of plantain are wastes and are shown to be a very good source of phyto-chemicals and dietary fibers which are beneficial to human body [7]. Converting plantain peel waste into biochar for lead adsorption is a green approach for waste re-utilization and biochar has long been used as a sequestering agent for heavy metals, dyes and other environmental contaminants. Various techniques are available for the removal heavy metals from wastewaters, surface and underground waters. These methods are chemical precipitation, ion exchange, filtration, evaporation, reverse osmosis, solvent extraction, electrochemical treatment, membrane separation and activated carbon adsorption [7-9]. However, all these methods are either inefficient or not economical when heavy metal exists in lower concentrations [8]. For instance, activated carbon a commonly used adsorbent for removal of various pollutants from wastewater has been jettisoned due to its high cost [9]. Consequently, it is important to find new methods for removing heavy metals from water and wastewater. Comparing with other conventional treatment techniques, adsorption was found to be a promising alternative technique for the removal of trace amount of heavy metals from water and wastewater. This is due to its convenience, ease of operation, and versatility. It minimizes or removes different types of pollutants, thus giving it a wide range of applications in wastewater treatment [9]. Predicting the rate at which adsorption takes place for a given system among other things, is the most important factor in adsorption system design, with adsorbate residence time and the reactor dimensions controlled by the system's kinetics [1]. Adsorption is a surface phenomenon that occurs when a solute is preferentially retained on the surface of an adsorbent forming a thin layer of the adsorbate [2]. The benefit or objectives of this research is bipodal as waste biomass of plantain peel which constitute serious environmental menance was converted to an environmentally friendly material for sustainable development. This involves the conversion of plantain peel to biochar by pyrolysis, activation of the biochar for surface functionality and secondly, lead (II) ions which has remained a problem for flora and fauna in water bodies as well as in other environmental matrices are removed by batch adsorption process. The adsorption of lead from aqueous was modeled using adsorption isotherms and kinetic models to identify the sorption mechanism. The batch adsorption process was studied under different conditions of time of contact, initial metal ion concentration and pH. The work is a clean-up exercise aimed at removing contaminants from water bodies. It is a continuation of our former work on the removal of zinc (II) ions from water samples previously published [7]. The main objective of this study was to synthesize, activate and apply plantain peel biochar for the removal of lead and thereafter profile the equilibrium and kinetic studies using the simulated data. 2.0. Materials and Methods 2.1. Materials Except otherwise stated, all analytical grade reagents used for the study ranging from lead acetate, Pb(CH3COO) 2+ , H2SO4, HNO3, Na2CO3, NaOH, Eriochrome black-T, EDTA and NaCl, were all obtained from Sigma Aldrich® and used without further purification. More so, to avoid interference of radicals, double distilled water was used for all experiments. 2.2. Characterization of the activated plantain peel biochar The BET surface area was measured using Micromeritics ASAP 2020 system. X-ray diffraction pattern was obtained on a Bruker® D8 Discover diffractometer, equipped with a Lynx Eye detector, under Cu-Ka radiation (l ¼ 1.5405 A). With data collected in the range of 2θ =10 to 100 o , scanning rate at 0.010 o min-1 , 192 s per step and samples placed on a zero background silicon wafer slide. 2.3. Sample Collection and Preparation The unripe plantain (Musa paradisiaca) was harvested from Abakaliki metropolis in Ebonyi state of Nigeria in a sac bag. The peels were carefully removed cleaned of soil and other impurities, sun dried to reduce moisture content for 7 days and then oven dried at 60 ± 1 o C for 24 h. The modified method (13) was adopted for carbonization of the plantain peels. This was done at a temperature of 600 ± 1 o C in nitrogen environment in a muffle furnace for 6 h. The

Dye was extracted from whole plant of Justicia carnea hooker, using soxhlet
extraction method. The dyestuff extracted gave a percentage yield of 92.8% and was
successfully applied on leather, cotton, and wool. The extracted dye showed solubility in
distilled water, HCl, H2SO4, ethanol and NaHCO3 respectively. Dye extract also shows a
pH 9, TLC revealed blue, green and yellow colours with RF values of 0.83, 0.86 and 0.89,
λmax was 480 and gave a green shade. Sulphanilic diazonium chloride was used as the
coupler and it produced a brown shade in each of the substrates applied on and fastness test
gave good result. pH for the coupled dye was 8.2 while TLC revealed yellow and orange
colours with RF values of 0.98 and 0.95 respectively. λmax obtained were 400nm and
480nm. Acid fastness, alkaline fastness, sunlight fastness and wash fastness of coupled dye
were determined and compared to a standard Gray Scale rating. Thin layer chromatography
carried out showed that dyestuff can be extracted from Justicia carnea hooker.
Keywords: Dye, Fastness, Extraction, Solubility.

The process of derivation of Adejo-Ekwenchi Adsorption Isotherm was discussed. Its rich application in characterisation of adsorption data was hi-lighted. And few challenges associated with isotherm, with suggestions on how to surmount them was presented.

The corrosion inhibition of aluminium by the ethanol extract of stem of Mucuna pruriens in 2 M H2SO4 solution was studied by the weight loss method at temperature range of 301 K to 313 K. The percentage inhibition efficiency, %IE was found to increase with both the inhibitor concentration and temperature. The increase in % IE with rise in temperature is suggestive of chemical adsorption process. The values of ΔGads are all negative an indication of the spontaneity of the adsorption process and below -20 kJ mol-1. Values of enthalpy of activation, ΔHads are positive and are lower than that of the blank, signifying inhibition effectiveness increases with increase in temperature. The data obtained there from best fitted the Freundlich, El-Awady, Temkin and Adejo-Ekwenchi isotherm. Due to conflicting figures obtained from the values of activation energy as to which of the mechanism of adsorption the inhibitor followed, the Adejo-Ekwenchi Isotherm was used to resolve the ambiguity and is chemisorption.

Surface of activated carbon can be functionalized with amine groups to enhance their capacity for CO 2 adsorption. Amine functionalized solid sorbents were prepared by anchoring two types of amine compounds, namely ethylenediamine (EDA) and 2-chloroethylamine hydrochloric acid (CEA) on the surface of palm shell based activated carbon (PSAC). Samples of PSAC were first oxidized by nitric acid using three different available setups to ensure about creation of a significant amount of oxygen containing groups on the surface. At the second stage, the best oxidized sample was modified by anchoring EDA and CEA on the surface to produce a superior CO 2 adsorbent. Several quantitative and qualitative methods were used to characterize the prepared samples: Nitrogen adsorption at 77K, proximate and ultimate analysis and temperature programmed desorption (TPD). Moreover, CO 2 adsorption study was carried out using CO 2 adsorption isothermal profile at 30°C and temperature-programmed (TP) CO 2 adsorption test. All modified samples had a lower surface area than the virgin PSAC. The best modified sample presented an increase of 45% in CO 2 capture capacity at 100°C. On the other hand, on the basis of unit surface area, CO 2 capture capacity of amine modified samples was much higher, compared to the parent sample. Furthermore, the modified samples showed a less dependency of their CO 2 capacity on temperature indicating chemisorption of the adsorbate on the PSAC surface. © 2011 IEEE.

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The adsorption of ethanolic root extract of Portulaca oleracea as corrosion inhibitor for the corrosion of mild steel in H 2 SO 4 medium at the temperature range of 305K to 315 K was studied using weight loss method and characterized using the common adsorption isotherms. The inhibition efficiency, IE%, was found to increase with both increase in the inhibitor concentration and rise in temperature. The increase in IE% with rise in temperature is suggestive of chemisorption. The adsorption best fitted the Langmuir, El-Awady, Temkin and Adejo-Ekwenchi isotherms. Evaluated values of free energy, ΔG ads , of the adsorption process were found to be all negative, indicative of spontaneity of the adsorption process and values obtained through the Temkin were above -20 kJ/mol, supportive of the chemisorption. The fact that the slopes and intercepts of the ideal Langmuir isotherm (ILI) plots were not unity and zero, respectively, signifies a deviation from this isotherm but the deviation cannot be said to be much as ΔG ads values obtained through modified Langmuir isotherm (MLI) are not quite different from those of ILI. The adherence of the adsorption to the Temkin isotherm is evidence evident of chemisorption, which was made evidently made clear from the Adejo-Ekwenchi b parameter. The exact number of water molecules replaced by inhibitor molecules could not be ascertained by Bockris-Swinkels isotherm.

The adsorption of ethanolic root extract of Portulaca oleracea as corrosion inhibitor for the corrosion of mild steel in H 2 SO 4 medium at the temperature range of 305K to 315 K was studied using weight loss method and characterized using the common adsorption isotherms. The inhibition efficiency, IE%, was found to increase with both increase in the inhibitor concentration and rise in temperature. The increase in IE% with rise in temperature is suggestive of chemisorption. The adsorption best fitted the Langmuir, El-Awady, Temkin and Adejo-Ekwenchi isotherms. Evaluated values of free energy, ΔG ads , of the adsorption process were found to be all negative, indicative of spontaneity of the adsorption process and values obtained through the Temkin were above -20 kJ/mol, supportive of the chemisorption. The fact that the slopes and intercepts of the ideal Langmuir isotherm (ILI) plots were not unity and zero, respectively, signifies a deviation from this isotherm but the deviation cannot be said to be much as ΔG ads values obtained through modified Langmuir isotherm (MLI) are not quite different from those of ILI. The adherence of the adsorption to the Temkin isotherm is evidence evident of chemisorption, which was made evidently made clear from the Adejo-Ekwenchi b parameter. The exact number of water molecules replaced by inhibitor molecules could not be ascertained by Bockris-Swinkels isotherm.