Methylene Blue Adsorption onto NaOH Modified Durian Leaf Powder: Isotherm and Kinetic Studies

Abstract

Durian leaf powder was treated with NaOH to introduce more carboxylate (-COO - ) groups in order to improve its performance as an adsorbent. The interaction between chemically treated durian leaf powder (CTDLP) and methylene blue (MB) was examined by using a Fourier Transform Infrared (FTIR) spectrometer. Surface modification of CTDLP was examined by using a Scanning Electron Microscope (SEM). Batch adsorption study was applied to investigate the effects of contact time, initial dye concentration, adsorbent dosage and pH of dye solution on MB adsorption. The experimental data best fitted with Langmuir model (R 2 > 0.989) with a maximum monolayer adsorption capacity of 125 mg g −1 . The kinetic studies showed good correlation with pseudo-second-order model, suggesting that the MB adsorption involved chemisorption process. This study revealed CDTLP as a potential adsorbent for MB removal from wastewater.