AlSaba Gul, Sultan Alam, Muhammad Ilyas, Muhammad Zahoor, Muhammad Naveed Umar, Riaz Ullah, Zafar Iqbal
{"title":"Removal of acidic dyes; acid yellow 25 and acid red 4 from wastewater by degassed activated carbon","authors":"AlSaba Gul, Sultan Alam, Muhammad Ilyas, Muhammad Zahoor, Muhammad Naveed Umar, Riaz Ullah, Zafar Iqbal","doi":"10.1515/pac-2024-0240","DOIUrl":null,"url":null,"abstract":"Activated carbon was prepared at 300 °C and 600 °C, characterized by SEM, EDX and XRD, and was then used as an adsorbent for the removal of acidic dyes; acid yellow 25 and acid red 4. The activated carbon prepared at high temperature (600 °C) due to its high carbon contents and surface area was subsequently used as adsorbent for the selected dyes adsorption using batch adsorption approaches to estimate different adsorption parameters. For the estimation of kinetics and equilibrium parameters a number of kinetics and isotherm models were employed. Dyes were adsorbed on activated carbon surface at a high rate for the first 15 min, after which it began to diffuse into the micro pores and thus the process became steady. The rate constant was estimated for first and second order kinetics models. The maximum adsorption capacities recorded were 526.32 mg g<jats:sup>−1</jats:sup> for acid red 4 and 555.55 mg g<jats:sup>−1</jats:sup> for acid yellow 25. The enthalpy change values recorded were; 19.44 kJ mol<jats:sup>−1</jats:sup> for acid yellow 25 adsorption and 16 kJ mol<jats:sup>−1</jats:sup> for acid red 4 adsorption, meant that the process is endothermic. The negative values of Gibbs free energy change (−393.28, −1,515.48, −2,634.68 J mol<jats:sup>−1</jats:sup>) of acid red 4 and acid yellow 25 (−251.72, −1,058.06, −2,367.84 J mol<jats:sup>−1</jats:sup>) at tested temperatures, confirmed the feasibility and spontaneity of the adsorption processes. The adsorption of dyes on the carbon surface was diffusion-controlled process, as demonstrated by the linear graph of intraparticle diffusion model.","PeriodicalId":20911,"journal":{"name":"Pure and Applied Chemistry","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Pure and Applied Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1515/pac-2024-0240","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Activated carbon was prepared at 300 °C and 600 °C, characterized by SEM, EDX and XRD, and was then used as an adsorbent for the removal of acidic dyes; acid yellow 25 and acid red 4. The activated carbon prepared at high temperature (600 °C) due to its high carbon contents and surface area was subsequently used as adsorbent for the selected dyes adsorption using batch adsorption approaches to estimate different adsorption parameters. For the estimation of kinetics and equilibrium parameters a number of kinetics and isotherm models were employed. Dyes were adsorbed on activated carbon surface at a high rate for the first 15 min, after which it began to diffuse into the micro pores and thus the process became steady. The rate constant was estimated for first and second order kinetics models. The maximum adsorption capacities recorded were 526.32 mg g−1 for acid red 4 and 555.55 mg g−1 for acid yellow 25. The enthalpy change values recorded were; 19.44 kJ mol−1 for acid yellow 25 adsorption and 16 kJ mol−1 for acid red 4 adsorption, meant that the process is endothermic. The negative values of Gibbs free energy change (−393.28, −1,515.48, −2,634.68 J mol−1) of acid red 4 and acid yellow 25 (−251.72, −1,058.06, −2,367.84 J mol−1) at tested temperatures, confirmed the feasibility and spontaneity of the adsorption processes. The adsorption of dyes on the carbon surface was diffusion-controlled process, as demonstrated by the linear graph of intraparticle diffusion model.
期刊介绍:
Pure and Applied Chemistry is the official monthly Journal of IUPAC, with responsibility for publishing works arising from those international scientific events and projects that are sponsored and undertaken by the Union. The policy is to publish highly topical and credible works at the forefront of all aspects of pure and applied chemistry, and the attendant goal is to promote widespread acceptance of the Journal as an authoritative and indispensable holding in academic and institutional libraries.