Equilibrium and Kinetic Studies on the Adsorption of Acid Yellow 36 Dye by Pinecone

Background & Aims of the Study: Dyes have significant role in environmental problems, due to their toxic effects on the food chain and sources of water. The purpose of this research was to study the adsorption of acid yellow 36 dye onto pinecone using batch system. Materials & Methods: This research was performed at laboratory scale and batch system. Equilibrium isotherms were modeled using Langmuir, Freundlich, and D-R models. Also kinetic studies were done by three models of pseudo first order, pseudo second order, and intra-particle diffusion. Results: The maximum adsorption was achieved at pH 5.0, adsorbent dose 0.7 g/l and contact time 20 min. The equilibrium adsorption capacity (mg/g) increased with increasing initial dye concentration. The Langmuir model (R2=0.99) provided the best fit for the experimental data. The adsorption kinetics were studied and best fit was achieved by pseudo- second order model (R2= 0.96). Conclusions: According to the results obtained of equilibrium and kinetic studies on the adsorption of acid yellow 36, pinecone can be a suitable and efficient adsorbent in the removal of yellow acid 36 dye from industrial wastewater.