Lignin is a major by-product problem for the pulp and paper industry. In our previous work, lignin was successfully separated from alkali lignin wastewater using iron (III) trimesic (Fe-BTC). This separation resulted in three layers: supernatant, lignin sludge, and Fe-BTC powder. In this study, the lignin separated by Fe-BTC (LSF) was expected to be used as an adsorbent for reactive red-120 dye (RR-120) removal. The LSF morphology was characterized by scanning electron microscope and energy dispersive X-ray spectrometer (SEM-EDS), the specific surface area was analyzed by Brunauer-Emmett-Teller (BET) method, and the functional groups were investigated by Fourier transform infrared (FTIR) spectrometer. The removal performance of LSF over RR-120 was approximately 35% in 60 min. The maximum adsorption capacity of LSF for RR-120 was found to be 10.363 mg/g. The adsorption kinetic of RR-120 removal fitted well with the pseudo-second-order kinetic model. The adsorption isotherm model of LSF also fitted with the Langmuir isotherm model. This research suggests the high potential of LSF as a lignin-based adsorbent agent for RR-120 removal in water.
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E-mail: visanu@kku.ac.th
