Abstract Description: Excess phosphate in the water body contributes to eutrophication and results in negative impacts to water quality, such as the harmful algal bloom (HAB) found in Lake Erie in the Toledo OH area. Among various phosphate absorption technologies, biochar made from waste biomass is a promising one. This technology can divert waste biomass form landfill, and the P-enriched biochar can be returned to soil to reduce chemical fertilizer use.
Therefore, the goal of this study is to develop a novel and cost-effective approach to absorb aqueous phosphate to prevent harmful algal blooms. Biochar was made by spent coffee grounds (SCG). Iron was added to the biochar to enhance P-absorption, prior to pyrolysis (pre-treatment). Two types of iron salts were used, one chloride and one sulfate based.
Both biochars were characterized with SEM and FTIR, and then tested for their effectiveness in phosphate (P) absorption at different concentrations. After P-absorption, desorption was also performed. The mechanisms of P absorption were investigated and compared with similar studies. This technology is an environmentally friendly approach for HAB reduction. In addition, this process can divert waste biomass from landfill and return the end product to soil as a slow-release fertilizer. This process can reduce the carbon footprint from many aspects: reuse of waste biomass and reduction of fertilizer use.
