COMPARISON OF BASIC DYESTUFF ADSORPTION CAPACITIES OF ACTTVATED CARBONS PRODUCED BY ZnCI2 AND H3PO4 ACTIVATION

Demiral İ., Samdan C., Demiral H.

FRESENIUS ENVIRONMENTAL BULLETIN, cilt.29, sa.3, ss.1304-1315, 2020 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Sayı: 3
  • Basım Tarihi: 2020
  • Dergi Adı: FRESENIUS ENVIRONMENTAL BULLETIN
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Agricultural & Environmental Science Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Environment Index, Geobase, Greenfile, Metadex, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.1304-1315
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

Activated carbons of different characteristics have been prepared from pumpkin seed shells using H3PO4 (HAC) and ZnCI2 (ZnAC) as activating agents. Surface area affecting adsorption ability of activated carbons based on adsorption of nitrogen (N-2) gas from the liquid nitrogen environment at 196 degrees C by the Brunauer, Emmet, and Teller (BET) method was measured as 1421 m(2) g(-1) and 1564 m(2) g(-1) for HAC and ZnAC, respectively. The efficiency of methylene blue (MB) adsorption of both activated carbons was compared by using various parameters such as pH, contact time, temperature, and adsorbent dose. Adsorption kinetics data were analyzed using three different kinetic models: pseudo-first-order, pseudo-second-order, and intraparticle diffusion model. The highest correlation coefficient for both activated carbons was obtained in the pseudo-second-order kinetic model. Adsorption isotherms were described using the Langmuir and Freundlich models at different temperatures. The experimental adsorption parameters fitted to Langmuir' s model with maximum adsorption capacities are 147.05 mg of MB g(-1) HAC and 181.81 mg of MB g(-1) ZnAC. Thermodynamic properties of the adsorption of methylene blue onto HAC and ZnAC were also determined. It was determined that this process can be both spontaneous and endothermic. Microwave regeneration of both activated carbons saturated with methylene blue was also studied. The regenaration cycle runs were initialized after the most suitable microwave electric power was specified. At the end of seventh cycle, regeneration yield for HAC was higher than ZnAC by approximately 30%. The activated carbon prepared using ZnCI2 was more effective for MB removal compared to that of H3PO4.