REMOVAL OF LIGNIN AND TANNIN COLOR FROM AQUEOUS-SOLUTION BY ADSORPTION ONTO ACTIVATED-CHARCOAL

Sorptive uptake of lignin and tannin from an aqueous phase by activate d charcoal was investigated in the laboratory. The sorption reaction w as found to be of a first order. The influence on the rate of sorption of various factors, such as amount of sorbent and pH of the system, h ave been investigated. Sorption data fit well into the Langmuir adsorp tion isotherm, indicating formation of a monolayer over a homogeneous sorbent surface. Sorption capacity, rate constant, intraparticle diffu sion coefficient, etc. were calculated from the sorption data. Desorpt ion studies indicate the irreversible nature of the sorption reaction, whereas interruption studies suggest film diffusion to be rate limiti ng. (C) 1997 Elsevier Science Ltd.