Green iron oxide-modified biochar for methylene blue removal from aqueous solutions
by Samaraweera, H.; Andrena, D.; Carter, K.; Felder, T.; Nawalage, S.; Chui, I. W.; Perez, F.; Khan, A.; Mlsna, T.
Textile industrial wastewater, a major source of effluent coloration, has been identified as a threat to human and animal health. A difficult and significant challenge is the complete removal of poorly biodegradable dyestuffs from complex environmental matrices. We synthesized a green iron oxide-loaded Douglas fir biochar (FDBC) hybrid using commercially available biochar, DBC, to effectively remove aqueous methylene blue (MB). Both modified and pristine adsorbents are microporous, and their MB removal speeds are very high (equilibrate in 5 min) at an initial MB concentration of 25 ppm. Large surface areas (640 m2/g versus 248 m2/g) and pore volumes (0.13 cm3/g versus 0.07 cm3/g) of DBC and FDBC partially facilitate MB surface physisorption. Compared to DBC, the maximum Langmuir adsorption capacity of FDBC is higher (634.0 mg/g versus 740.5 mg/g), indicating the hybrid adsorbent design that involves the iron oxide phase plus the biochar backbone (1500 ppm initial [MB], t = 5 min, and pH 6.8). The addition of Fe3O4 nanoparticles (-11.0 nm) promotes the adsorption of MB on FDBC (due to the increase in the surface Fe3O4 concentration), while allowing small adsorbent particles of spent FDBC to be easily removed from batch treatments using a magnet. The magnetic variant (FDBC) simultaneously adsorbs three co-existing BP, BG, and MB with over-90% efficiency. Spent FDBC could be regenerated easily by stirring in Methanol. FDBC would be more economical in terms of its facile synthesis, efficient and fast MB adsorption, convenient recovery, pH-independent MB uptake, and treatment of variety of wastewaters etc.
- Journal
- Groundwater for Sustainable Development
- Volume
- 21
- Year
- 2023
- URL
- https://dx.doi.org/10.1016/j.gsd.2023.100945
- ISBN/ISSN
- 2352-801X
- DOI
- 10.1016/j.gsd.2023.100945