(31l) Chlorella for Heavy Metal Removal from Wastewater Via Biosorption Followed By Hydrothermal Conversion for Waste Reutilization

Numerous industries produce massive amounts of heavy metals that pollute our freshwater. These pollutants are harmful to both the ecosystem and the humans that ingest it. One efficient and cost-effective solution is biosorption. Chlorella can remove single or multiple metals effectively when tested individually, however industrial pollution rarely ever contains only one metal. It is critical to determine the adsorption efficiencies of certain metals with the interference of other metals. In this study, we investigate both individual and competitive biosorption of various concentrations of Cu and Cd. Biosorption data were modeled by both the pseudo-first and pseudo-second order kinetic models and the Langmuir and Freundlich isotherm models. The current modeling results indicate that the biosorption capacity of chlorella for Cd and Cu decreases with the interference of Cu and Cd, respectively. However, the interference of Cu on Cd is more severe than that of Cd on Cu. Further details will be presented. Hydrothermal Conversion (HTC) of Cu- and/or Cd contaminated chlorella, using microwave at 220°C, produce about 18-24% of bio-oils and 15-28% of hydrochars. These yields will be optimized using different microwave HTC programs, including heating rate, temperature, and residence time. The detailed results will be discussed in the presentation.