Mohamad, M. and Wannahari, R. and Azzahra Ahmad Kamal, A. and Mohammad, R. and Che Zaudin, N.A. and Shwu Hwa, C. and Wei, L.J. (2020) SPENT COFFEE GROUNDS BIO CHAR AS A LOW-COST ADSORBENT FOR METHYLENE BLUE REMOVAL FROM AQUEOUS SOLUTION: OPTIMISATION USING RESPONSE SURFACE METHODOLOGY. ARPN Journal of Engineering and Applied Sciences, 15 (3). pp. 437-447. ISSN 18196608