Particle Size Effect on the Water Vapour – Activated Tamarind Seeds (Tamarindus indica L.) Toward the Adsorbent Physical Properties

The increasing problem of dyestuff liquid waste in the textile industry occurs due to the low adsorption of textiles toward dyes. Therefore, various efforts have been made to enhance the fabric’s absorption. One method that has been done is by adding biomass-derived dye-binding additives which act as an adsorbent. One of potential biomasses is tamarind seeds. The purpose of this study is to determine the effect of particle size of tamarind seeds, which is physically activated, on the adsorbent character. The variation of adsorbent particle size applied were -80 + 100 mesh (177-149 μm), -100 + 120 mesh (149- 125 µm), -120 + 150 mesh (125-99.3 µm) and less than 150 mesh (<99.3 µm). Tamarind seed was activated using water vapour at high pressure prior to the application. The adsorbent characters were studied based on particle size distribution, powder porosity, average relative molecular mass, and hydrophilicity. In addition, tamarind seed chemical structure was analysed using Fourier Transform Infra-Red (FTIR) spectrophotometry, while adsorbent potency was studied in the form of an adsorbent thin film. The results showed that based on the analysis of particle size distribution, adsorbents with the best activation results was obtained by particle size of 125-149 μm. The highest porosity was achieved by particle that smaller than 99.3 µm and the highest average relative molecular mass, based on the Mark–Houwink approach, was obtained by particle size of 125-149 µm. The highest hydrophilicity, which was determined based on the contact angle, was obtained by particle sizes of 99.3-125 µm.