Eucheuma cottonii seaweed-based biochar for adsorption of methylene blue dye

• Main Authors: Saeed, A.A.H., Harun, N.Y., Sufian, S., Siyal, A.A., Zulfiqar, M., Bilad, M.R., Vagananthan, A., Al-Fakih, A., Ghaleb, A.A.S., Almahbashi, N.
• Format: Article
• Published: MDPI 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098481624&doi=10.3390%2fsu122410318&partnerID=40&md5=90a6e9bd02ae6fcb6affc15d11f6803b; http://eprints.utp.edu.my/32419/

Pollution from dye containing wastewater leads to a variety of environmental problems, which can destroy plant life and eco-systems. This study reports development of a seaweed-based biochar as an adsorbent material for efficient adsorption of methylene blue (MB) dye from synthetic wastewater. The Eucheuma cottonii seaweed biochar was developed through pyrolysis using a tube furnace with N2 gas, and the properties were later improved by sulfuric acid treatment. The adsorption studies were conducted in a batch experimental setup under initial methylene blue concentrations of 50 to 200 mg/L, solution pH of 2 to 10, and temperature of 25 to 75�C. The characterization results show that the developed biochar had a mesoporous pore morphology. The adsorbent possessed the surface area, pore size, and pore volume of 640 m2/g, 2.32 nm, and 0.54 cm3/g, respectively. An adsorption test for 200 mg/L of initial methylene blue at pH 4 showed the best performance. The adsorption data of the seaweed-based biochar followed the Langmuir isotherm adsorption model and the pseudo-second-order kinetic model, with the corresponding R2 of 0.994 and 0.995. The maximum adsorption capacity of methylene blue using the developed seaweed-based biochar was 133.33 mg/g. The adsorption followed the chemisorption mechanism, which occurred via the formation of a monolayer of methylene blue dye on the seaweed-based biochar surface. The adsorption performance of the produced seaweed biochar is comparable to that of other commercial adsorbents, suggesting its potential for large-scale applications. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.