Among cationic and anionic dyes, Rhodamine-B (Rh-B) and Methyl Orange (MO) are commonly used in the chemical industry, such as textile industry. These dyes, especially Rh-B, are known to be toxic and carcinogenic, and their presence in water effluents has been widely studied. In this study, the adsorbent was prepared by activating East Kalimantan’s low-rank coal (LRC) with a 30 % phosphoric acid solution (H3PO4). The aim of this research was to assess the effectiveness of activated LRC as an adsorbent in the adsorption process for Rh-B and MO dye removal. The best results for Rh-B and MO dye removal were obtained with an adsorbent dosage of 100 mg, a contact time of 10 minutes (for Rh-B) and 5 minutes (for MO), and a pH of 5 for Rh-B and 4 for MO. The Rh-B dye removal efficiency was 52.4405 % and 97.59 % for MO. The findings on the present investigation provide valuable insights into the use of activated East Kalimantan’s LRC as an adsorbent for Rh-B and MO dye removal.
Patmawati et al. (Tue,) studied this question.