Removal of some organic dyes by acid-treated spent bleaching earth

摘要

Acid treated spent bleaching earth was prepared by treating spent bleaching earth, a waste material from the palm oil industry, with 20/100 sulphuric acid and heated at 350 deg. C for three hours. This materials can efficiently sorb a variety of organic dyes especially reactive and acid dyes, with maximum sorption capacity in the order of 2-300 mg g~-1. The applicability of both the Langmuir and Freundlich isotherms to the experimental data indicates that both physicosorption and chemisorption were involved in the sorption process.