Wahyuni, PutriMuhdarina, Muhdarina2018-03-072018-03-072018-03-07wahyu sari yenihttps://repository.unri.ac.id/xmlui/handle/123456789/9285The research used the catappa shell (terminalia catappa) that grown around in Riau University as an adsorbent for blue methylene adsorption. The catappa shell was carbonized in various time such 30, 60 and 90 minutes. pHzpc biocharcoals were measured to know the surface characterictic of adsorbent. Adsorption process was done using batch method to determine the optimum pH, adsorbent dosis and adsorbat concentration in adsorption process. The results of this research showed that % adsorption BCK-60 in various pH and adsorbent dosis has higher than BCK-30 and BCK-90, while various concentrations of BCK-30 has effiency of adsorption higher than that of BCK-60 and BCK-90.enadsorptioncatappa shellisotermpHzpcArticle