(418d) The Effect of Modified Biochar on Harmful Algal Bloom Remediation

Water is a critical resource essential for sustaining life, providing a vital habitat for plants, animals, and humans. In recent years, coastal ecosystems have been increasingly impacted by harmful algal blooms (HABs), which adversely affect marine environments and disrupt both fisheries and the tourism sector.

This has prompted extensive research and efforts to develop effective strategies for mitigating the presence of HABs in affected ecosystems. In this study, Karenia, a common HAB, was sought to be remediated through the use of modified biochar composed of loblolly pine (LP) and polyaluminum chloride (PAC). Three distinct methods were employed to produce modified biochar: pre-impregnation, post-impregnation, and physical mixing.

In order to synthesize the modified biochar, raw biomass, LP, was impregnated with PAC at biomass-to-PAC ratios of 1:2, 1:5, and 1:10, before being activated at 600°C for 30min, to create pre-impregnated samples. A similar process was preformed where biochar are impregnated using the same ratios as above. Biochar and PAC were physically combined at 1:2, 1:5, and 1:10 ratios to create physically mixed samples. To characterize the modified biochars, a variety of characterizations were used. Surface porosity was quantified through the use of N₂ adsorption-desorption. The surface morphology was observed via the use of scanning electron microscopy, energy dispersive X-ray, X-ray powder diffraction, and proximate and ultimate analysis. Zeta potential was used to determine the surface ionization properties as well as the particle size distribution. It was observed in preliminary studies that the physical mixing was the most practical in remediating the Karenia, removing about 67% of the HAB from the solution.