scholarly journals Utilization of Agro-Waste in the Elimination of Dyes from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

Author(s):  
Nnaemeka John Okorocha ◽  
Chijioke E. Omaliko ◽  
Collins C. Osuagwu ◽  
Maureen O. Chijioke-Okere ◽  
Conrad K. Enenebeaku

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 Langmuir Isotherm for MG adsorption. The maximum adsorption capacity was found to be 13.02 mg/g and 9.41 mg/g for the adsorption of MG and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0, ΔH0 and ΔS0 obtained indicated the spontaneous and exothermic nature of the MG adsorption process while positive enthalpy (ΔH0) indicated an endothermic nature of CR adsorption process.

Author(s):  
Nnaemeka John Okorocha ◽  
J. Josphine Okoji ◽  
Charles Osuji

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 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.


Author(s):  
Conrad K. Enenebeaku ◽  
Nnaemeka J. Okorocha ◽  
Uchechi E. Enenebeaku ◽  
Ikechukwu C. Ukaga

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.


2020 ◽  
Vol 9 (1) ◽  
pp. 95-104

The impact of sodium hydroxide pretreatment of maize husk on its lead ion removal efficiency was investigated. Pretreatment of maize husk with this alkali increased its surface area and porosity from 528.74 m2/g and 0.477 cm3/g to 721.54 m2/g and 0.642 cm3/g, respectively. Batch adsorption studies were carried out to evaluate the effects of initial pH, adsorbent dose, initial lead ion concentration, initial solution temperature, and contact time on the adsorption process. The maximum removal efficiency of maize husk at pH 5 and adsorbent dose 2 g/L was 62.85 %, which increased to 82.84 % after pretreatment and was attained in 15 min. The adsorption data for the natural and pretreated maize husk were best fitted in the Freundlich isotherm model, with their adsorption intensity (n) having values >1, which indicated that lead ion adsorption onto the adsorbent types was a favorable physical process. The adsorption of lead ions onto the adsorbents followed the pseudo-first-order kinetic model. The experimental adsorption capacities of maize husk (31.43 mg/g) and its modified form (41.22 mg/g) were very close to those obtained from this model (31.03 mg/g and 40.65 mg/g respectively). The ΔH and ΔG values of the adsorption process showed that the adsorption of lead ions by both adsorbents was an endothermic process and occurred spontaneously. Alkali pretreated maize husk can therefore be used as a cheap adsorbent to remove lead ions from aqueous solution.


Author(s):  
Conrad Kenechukwu Enenebeaku ◽  
Ikechukwu C. Ukaga ◽  
Nnaemeka John Okorocha ◽  
Benedict Ikenna Onyeachu

The adsorption of methyl violet (MV) dye onto white potato Peel powder from aqueous solution was investigated by analyzing the operational parameters such as contact time, adsorbent dosage, initial dye concentration, PH and temperature to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MV onto the adsorbent (WPPP) was found to be contact time (120 mins), PH (10.0) and temperature (303K) for an initial MV dye concentration of 50mg/l and adsorbent dose of 1.0g. The experimental equilibrium adsorption data of the (MV) dye fitted best and well to the freundlich isotherm model. The maximum adsorption capacity was found to be 17.13mg/g for the adsorption of MV. The kinetic data conforms to the pseudo – second order kinetic model.


2016 ◽  
Vol 6 (3) ◽  
pp. 377-388 ◽  
Author(s):  
Ibrahim Umar Salihi ◽  
Shamsul Rahman Muhamed Kutty ◽  
Muhamed Hasnain Isa ◽  
Nasir Aminu

Pollution caused by heavy metals has become a serious problem to the environment nowadays. The treatment of wastewater containing heavy metals continues to receive attention because of their toxicity and negative impact on the environment. Recently, various types of adsorbents have been prepared for the uptake of heavy metals from wastewater through the batch adsorption technique. This study focused on the removal of zinc from aqueous solution using microwave incinerated sugarcane bagasse ash (MISCBA). MISCBA was produced using microwave technology. The influence of some parameters such as pH, contact time, initial metal concentration and adsorbent dosage on the removal of zinc was investigated. The competition between H+ and metal ions has affected zinc removal at a low pH value. Optimum conditions for zinc removal were achieved at pH 6.0, contact time 180 min and adsorbent dosage of 10 g/L, respectively. The maximum adsorption capacity for the removal of zinc was found to be 28.6 mg/g. The adsorption process occurred in a multilayered surface of the MISCBA. Chemical reaction was the potential mechanism that regulates the adsorption process. MISCBA can be used as an effective and cheap adsorbent for treatment of wastewater containing zinc metal ions.


2021 ◽  
Author(s):  
Sabarish Radoor ◽  
Jasila Karayil ◽  
Aswathy Jayakumar ◽  
Jyotishkumar Parameswaranpillai ◽  
Suchart Siengchin

Abstract In the present work, we modified ZSM-5 zeolite using a bio polymer poly (diallyl dimethyl ammonium chloride) and employed it for the removal of cationic dye, methylene blue from aqueous solution. The chemical and physical properties of the modified ZSM-5 zeolite were investigated using XRD, FTIR, SEM, TEM, nitrogen adsorption, TGA and 27Al NMR. Modified ZSM-5 zeolite possesses high surface area and pore diameter which was confirmed from SEM, TEM and nitrogen adsorption analysis. Adsorption of methylene blue on zeolite was investigated by batch adsorption technique. The effect of different parameters such as zeolite dosage, initial methylene blue concentration, temperature, pH and contact time on the adsorption process was discussed. Maximum adsorption capacity (4.31 mg/g) was achieved using 0.1g of modified ZSM-5 zeolite at the optimum conditions (initial dye concentration: 10 mg/L, pH: 10, temperature:30oC and contact time: 300 min). The experimental data were fitted into Langmuir and Freundlich models and the results indicate that the adsorption process followed Freundlich isotherm. Kinetic data were investigated using pseudo-first-order and pseudo-second-order models. Kinetic analysis indicates that pseudo-second-order model is more suitable to describe adsorption of MB on modified ZSM-5 zeolite. The reusability test suggests that the adsorbent could be reused at least six times without significant loss in removal efficiency.


2015 ◽  
Vol 11 (9) ◽  
pp. 3876-3887
Author(s):  
Prakash Bhila Wagh ◽  
V.S Shrivastava ◽  
V.S Shrivastava

 The kinetics and equilibrium study of crystal violate dye adsorption on mixture of activated carbon (PWCAC) and (CSAC) was studied. The use of low cost ecofriendly adsorbent has been investigated as an ideal alternative to the current expensive methods of removing of dye from aqueous solution. This study was done by batch adsorption techniques. The quantitative adsorption kinetic and equilibrium parameter for crystal violate dye were studied using uv-visible adsorption spectroscopy. The effect of initial dye concentration, pH,adsorbent dose, temperature, particle size were determined to find the optimal condition for adsorption. The percentage removal of dye was found to be most effective at pH10and contact time 120 min and at an adsorbent dose 4 g/L of dye. The study indicates that’s, the percentage removal of dye increases with increasing initial dye concentration, adsorption dose and contact time and attains equilibrium at optimum conditions.The equilibrium study of adsorption of crystal violate dye on to mixture of activated carbon was investigated using pseudo first order and pseudo second order kinetic models. The adsorption kinetics was found to follow pseudo second order kinetic model. The equilibrium adsorption data of crystal violate dye on PWCAC and CSAC mixture was analyzed by Langmuir and Freundlich adsorption model. The results show that the Langmuir model provides the best correlation.


2015 ◽  
Vol 11 (9) ◽  
pp. 3876-3887
Author(s):  
Prakash Bhila Wagh ◽  
V.S Shrivastava ◽  
V.S Shrivastava

 The kinetics and equilibrium study of crystal violate dye adsorption on mixture of activated carbon (PWCAC) and (CSAC) was studied. The use of low cost ecofriendly adsorbent has been investigated as an ideal alternative to the current expensive methods of removing of dye from aqueous solution. This study was done by batch adsorption techniques. The quantitative adsorption kinetic and equilibrium parameter for crystal violate dye were studied using uv-visible adsorption spectroscopy. The effect of initial dye concentration, pH,adsorbent dose, temperature, particle size were determined to find the optimal condition for adsorption. The percentage removal of dye was found to be most effective at pH10and contact time 120 min and at an adsorbent dose 4 g/L of dye. The study indicates that’s, the percentage removal of dye increases with increasing initial dye concentration, adsorption dose and contact time and attains equilibrium at optimum conditions.The equilibrium study of adsorption of crystal violate dye on to mixture of activated carbon was investigated using pseudo first order and pseudo second order kinetic models. The adsorption kinetics was found to follow pseudo second order kinetic model. The equilibrium adsorption data of crystal violate dye on PWCAC and CSAC mixture was analyzed by Langmuir and Freundlich adsorption model. The results show that the Langmuir model provides the best correlation.


Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.


2017 ◽  
Vol 13 (27) ◽  
pp. 425
Author(s):  
Azeh Yakubu ◽  
Gabriel Ademola Olatunji ◽  
Folahan Amoo Adekola

This investigation was conducted to evaluate the adsorption capacity of nanoparticles of cellulose origin. Nanoparticles were synthesized by acid hydrolysis of microcrystalline cellulose/cellulose acetate using 64% H3PO4 and characterized using FTIR, XRD, TGA-DTGA, BET and SEM analysis. Adsorption kinetics of Pb (II) ions in aqueous solution was investigated and the effect of initial concentration, pH, time, adsorbent dosage and solution temperature. The results showed that adsorption increased with increasing concentration with removal efficiencies of 60% and 92.99% for Azeh2 and Azeh10 respectively for initial lead concentration of 3 mg/g. The effects of contact time showed that adsorption maximum was attained within 24h of contact time. The maximum adsorption capacity and removal efficiency were achieved at pH6. Small dose of adsorbent had better performance. The kinetics of adsorption was best described by the pseudo-second-Order model while the adsorption mechanism was chemisorption and pore diffusion based on intra-particle diffusion model. The isotherm model was Freundlich. Though, all tested isotherm models relatively showed good correlation coefficients ranging from 0.969-1.000. The adsorption process was exothermic for Azeh-TDI, with a negative value of -12.812 X 103 KJ/mol. This indicates that the adsorption process for Pb by Azeh-TDI was spontaneous. Adsorption by Azeh2 was endothermic in nature.


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