Adsorption of Direct Dyes by the Regenerated Spent-bleaching Earth from Palm oil Refining Industry
The adsorption of three direct dyes namely Direct Red 80 (DR80), Direct Blue 71 (DB71) and Direct Orange 46 (DO46) by flesh (FBE) and regenerated spent-bleaching earth (RBE) from palm oil refining industry were studied. Spent-bleaching earth was regenerated by heat treatment at 550℃ for 2 hrs. Factors studied included initial pH, contact time. The adsorption capacity at room temperature (29-32℃) was calculated using Langmuir adsorption equation. The adsorptions of dyes were pH independent over the range of 4 to 8. The dye adsorptions of both FBE and RBE were second- order irreversible reaction. More than 80％ of dyes were adsorbed instantaneously at the beginning of the reactions, except for the adsorption of SBEDR 80. The Langmuir isotherm fitted the adsorption data well with the correlation coefficient (R<2>) greater than 0.963. By comparing the maximum molar adsorption capacity (Q<0>), the dye adsorbed by both FBE and RBE followed the order of DO46>DB71>DR80. The RBE can adsorbed DB71 as good as the FBE, while RBE has about 69％ and 28％ less capacity on DO46 and DR80 adsorption, respectively, comparing to the FBE.
Spent bleaching earth regeneration palm oil direct dye adsorptions.
W. Somboon S. Wanitjaroengam S. Muadchan
Department of Chemistry, Faculty of Science, King Mongkut S University of Technology Thonburi, Tungkru, Bangkok 10140, Thailand
国际会议
北京
英文
74-81
2007-08-20（万方平台首次上网日期，不代表论文的发表时间）