Production of demineralised high quality hierarchical activated carbon from lignite and determination of adsorption performance using methylene blue and p-nitrophenol: The role of surface functionality, accessible pore size and surface area

Chalil Oglou R., GÖKÇE Y., YAĞMUR E., AKTAŞ Z.

Journal of Environmental Management, vol.345, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 345
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jenvman.2023.118812
  • Journal Name: Journal of Environmental Management
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, International Bibliography of Social Sciences, PASCAL, Aerospace Database, Agricultural & Environmental Science Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Communication Abstracts, Environment Index, Geobase, Greenfile, Index Islamicus, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Accessible pore, Activated carbon, Adsorption, Methylene blue, Para-nitrophenol
  • Ankara University Affiliated: Yes


In the adsorption process, the surface area, pore and particle size distribution and the chemical structure of the solid and the type of adsorbent are of vital importance. Activated carbon (AC) is a very good adsorbent material and its cost is highly dependent on the starting material and production method. The pore size and functional structure of the surface depend on the amount of activation chemical used. Hierarchical ACs were produced from lignite by loading two different amounts of KOH. The impregnation ratio (KOH/lignite) was chosen as 1/1 and 3/1 and the produced ACs were labelled as AC1 and AC3. The surface areas of AC1 and AC3 were determined as 1321.3 and 2421.3 m2/g, and the total pore volumes were 1.079 and 1.425 cm3/g. Methylene blue (MB) and p-nitrophenol (p-NP) were used to determine the adsorption performance of the produced ACs. The adsorption data were evaluated in terms of the Langmuir and Freundlich models. The amounts of MB and p-NP adsorbed on the surface were calculated in mg/g, total and accessible surface area in mg/m2. It was determined that the MB and p-NP adsorbed to the AC1 sample were higher than the AC3 sample per m2 of population. Molecular orientation is possible depending on the solid surface functionality and chemical structure of the molecule to be adsorbed. It was concluded that in addition to the large surface area, the pore width that can be entered and the functional structure of the surface are very significant factors in the adsorption processes.