Adsorption of FFA in crude catfish oil onto chitosan, activated carbon, and activated earth: A kinetics study

The feasibility of using chitosan, activated carbon, and activated earth to remove FFA from crude catfish visceral oil, and the adsorption kinetics of the procedure were evaluated. The effect of adsorbents on water activity and the 18:3 and 22:6 content of crude catfish visceral oil was also studied. The initial adsorption kinetic coefficients of FFA (mL g(-1) min(-1)) were 0.1, 0.07, and 0.03 for chitosan, activated carbon, and activated earth, respectively. The external film mass-transfer coefficient (0.001 mL s(-1)) was similar for the three adsorbents. The adsorption capacity of FFA at saturation (mg g(-1)) was 71.2 for chitosan, 65.5 for activated carbon, and 57.0 for activated earth. The intraparticular diffusion coefficients (mg mL(-1) min(-0.5)) were 0.14, 0.12, and 0.09 for chitosan, activated carbon, and activated earth, respectively. Water activity of the crude oil decreased with increased contact time of the adsorbents. Results indicated that chitosan was a better adsorbent than activated carbon and activated earth for FFA removal from crude catfish visceral oil.