Langmuir and Freundlich isotherm adsorption using activated charcoal from banana peel to reduce total suspended solid (TSS) levels in tofu industry liquid waste

The tofu industry is currently growing very rapidly both on a home industry scale and on a factory scale, in the process of making tofu solid and liquid waste are produced. Solid waste is usually used for animal feed, while liquid waste is not treated. Tofu industrial liquid waste contains very high Total Suspended Solid (TSS), if the liquid waste is disposed of directly into the water it can pollute the aquatic ecosystem. One way to reduce pollution is to use activated charcoal from plantain peels as adsorbent. This study aims to determine the appropriate adsorption isotherm model in the absorption process to reduce the level of Total Suspended Solid (TSS) of tofu industrial wastewater with variations in the mass of activated charcoal (100 grams; 200 grams and 300 grams) and adsorption time (20 minutes; 40 minutes).; 60 minutes; 80 minutes and 100 minutes). The equation used in the adsorption process is the Langmuir and Freundlich isotherm adsorption equation. The experimental results show that the largest TSS value adsorbed by activated charcoal is 200 grams with a contact time of 60 minutes. The suitable equation for determining the maximum adsorption capacity of activated charcoal in the TSS absorption process of tofu industrial wastewater is the equation Freundlich with R2 = 1. The maximum adsorption power of activated charcoal on the TSS absorption of tofu industrial wastewater was 51,8134 mg / L.