A sugarcane-bagasse-based adsorbent employed for mitigating eutrophication threats and producing biodiesel simultaneously

• Main Authors: Wan Nurain Farahah, Wan Basri, Hanita, Daud, Lam, Man Kee, Cheng, C. K., Oh, Wen Da, Tan, Wen Nee, Maizatul Shima, Shaharun, Yeong, Yin Fong, Ujang, Paman, Kusakabe, Katsuki, Evizal, Abdul Kadir, Show, Pau Loke, Lim, Jun Wei
• Format: Article
• Language: English
• Published: MDPI AG 2019
• Subjects: TD Environmental technology. Sanitary engineering; TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/26860/1/A%20sugarcane-bagasse-based%20adsorbent%20employed%20for%20mitigating.pdf; http://umpir.ump.edu.my/id/eprint/26860/; https://doi.org/10.3390/pr7090572; https://doi.org/10.3390/pr7090572

Eutrophication is an inevitable phenomenon, and it has recently become an unabated threat. As a positive, the thriving microalgal biomass in eutrophic water is conventionally perceived to be loaded with myriad valuable biochemical compounds. Therefore, a sugarcane-bagasse-based adsorbent was proposed in this study to harvest the microalgal biomass for producing biodiesel. By activating the sugarcane-bagasse-based adsorbent with 1.5 M of H2SO4, a highest adsorption capacity of 108.9 ± 0.3 mg/g was attained. This was fundamentally due to the surface potential of the 1.5 M H2SO4 acid-modified sugarcane-bagasse-based adsorbent possessing the lowest surface positivity value as calculated from its point of zero charge. The adsorption capacity was then improved to 192.9 ± 0.1 mg/g by stepwise optimizing the adsorbent size to 6.7–8.0 mm, adsorption medium pH to 2–4, and adsorbent dosage to 0.4 g per 100 mL of adsorption medium. This resulted in 91.5% microalgae removal efficiency. Excellent-quality biodiesel was also obtained as reflected by the fatty acid methyl ester (FAME) profile, showing the dominant species of C16–C18 encompassing 71% of the overall FAMEs. The sustainability of harvesting microalgal biomass via an adsorption-enhanced flocculation processes was also evidenced by the potentiality to reuse the spent acid-modified adsorbent.