Adsorption of Mn(II) and Co(II) ions from aqueous solution using Maize cob activated carbon: Kinetics and Thermodynamics Studies

Journal of Applied Sciences and Environmental Management

BALOGUN, B. B.¹  JIMOH, A. A.¹  JAMIU, W.¹  ADEBAYO, G. B.¹  ADEGOKE, H. I.¹ 

关键词: Adsorption;    Heavy metals;    Kinetics;    Thermodynamics;   

DOI  :  

学科分类：环境科学（综合）

来源: University of Port Harcourt * Department of Pure and Industrial Chemistry

【 摘 要 】

The adsorption of Mn(II) and Co(II) ions from aqueous solution wasinvestigated using batch adsorption experiment at room temperature. The effect of pH,contact time, metal ion concentration and temperature were evaluated. The residualconcentrations of the metal ions were determined by atomic absorption spectrophotometer.The results showed that maximum removal of Mn(II) and Co(II) ions occurred at pH 9.Some physico-chemical and spectroscopic characterization of the adsorbents were done suchas moisture content, ash content, bulk density, volatile matter, iodine number, point of zerocharge (PZC), XRF, and FTIR. The moisture and ash content of MCAC adsorbent werefound to be 9.85±0.06 and 5.5±0.1% respectively. The bulk density was found to be0.37±0.01g/m3, iodine number of 367.66±30 mg/g and PZC of 6.8. The SEM micrographshows particle grains and jelly like rough surfaces, FTIR analysis results show differentfunctional group in the MCAB adsorbent such as O-H, C=O, and C=C stretching. Kineticstudy shows that the pseudo-second order kinetic model best described the adsorption ofmetal ions. The equilibrium data fitted Langmuir, Freundlich and Temkin adsorptionisotherms, in each case, the Langmuir model appears to have better regression coefficientsthan the Freundlich and Temkin. Thermodynamics investigation showed that Gibb’s freeenergy change (ΔG) was negative indicating that the adsorption of Mn(II) and Co(II) ions bymaize cob activated carbon were feasible and spontaneous. The positive value of enthalpychange (ΔH) implies that the reaction was endothermic while positive value of entropychange (ΔS) implies an irregular increase in the randomness at the solid/solution interface ofthe adsorbent during the adsorption process.

【 授权许可】

Unknown