Single, competitive, and dynamic adsorption on activated carbon of compounds used as plasticizers and herbicides.
The main aim of this study was to investigate the single, competitive, and dynamic adsorption of phthalic acid (PA), bisphenol A (BPA), diphenolic acid (DPA), 2,4-dichlorophenoxy-acetic acid (2,4-D), and 4-chloro-2-methylphenoxyacetic acid (MCPA) on two activated carbons with different chemical natures and similar textural characteristics. The adsorption mechanism was also elucidated by analyzing the influence of solution pH and ionic strength. The activated carbons demonstrated high adsorption capacity to remove all micropollutants due to the presence of active sites on their surfaces, which increase dispersive interactions between the activated carbon graphene layers and the aromatic ring of pollutants. The adsorption capacity of the activated carbons increased in the order: DPA<BPA<PA<2,4-D<MCPA, which is directly related to: i) molecular size of pollutants; ii) chemical structure of pollutants, and iii) chemical properties of adsorbents. In most cases, the adsorption of contaminants is favored at acid pH (pH<5) due to the establishment of attractive electrostatic interactions. In dynamic regime, the amount of pollutant adsorbed was much higher for PA, followed by DPA, and was approximately similar for BPA, 2,4-D, and MCPA. Finally, the amount of BPA and DPA adsorbed on activated carbon decreased by around 50% and 70% in the presence of DPA and BPA, respectively, indicating that both compounds are adsorbed on the same adsorption sites of the activated carbon.
Inorganic Chemistry Department, Faculty of Science, University of Granada, 18071 Granada, Spain; Environmental Engineering Department, Faculty of Engineering, Zagazig University, 44519 Zagazig, Egypt. Electronic address: engdaim@ugr.es.
Mahmoud M
MM
Abdel daiem
Inorganic Chemistry Department, Faculty of Science, University of Granada, 18071 Granada, Spain. Electronic address: jrivera@ugr.es.
José
J
Rivera-Utrilla
Inorganic Chemistry Department, Faculty of Science, University of Granada, 18071 Granada, Spain. Electronic address: mansanch@ugr.es.
Manuel
M
Sánchez-Polo
Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosi, Av. Dr. M. Nava No.6, San Luis Potosi, SLP 78210, Mexico. Electronic address: raul_iqi@yahoo.com.mx.
Raúl
R
Ocampo-Pérez
D015084:2,4-Dichlorophenoxyacetic Acid; D000327:Adsorption; D001559:Benzhydryl Compounds / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D008956:Models, Chemical; D009994:Osmolar Concentration; D010636:Phenols / Q000737:chemistry; D010795:Phthalic Acids / Q000737:chemistry; D010968:Plasticizers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D000098826:Bisphenol A Compounds
D015084:2,4-Dichlorophenoxyacetic Acid; D001559:Benzhydryl Compounds; D002606:Charcoal; D006540:Herbicides; D010636:Phenols; D010795:Phthalic Acids; D010968:Plasticizers; D014874:Water Pollutants, Chemical; C032279:phthalic acid; C006780:bisphenol A; D000098826:Bisphenol A Compounds
Adsorption; Competitive; Landfill leachate; Micropollutants