State Water Resources Research Institute Program
Project Id: 2010AK94B
Title: Application of citrus peel biosorbents in repeated adsorption/desorption cycles for removal of heavy metals from waste waters
Project Type: Research
Start Date: 3/01/2010
End Date: 2/28/2011
Congressional District: Ak-001
Focus Categories: Treatment, Models, Wastewater
Keywords: biosorption, mine tailings, desorption, columns
Principal Investigator: Schiewer, Silke (University of Alaska Fairbanks, WERC (Water & Environmental Research Center))
Federal Funds: $ 22,520
Non-Federal Matching Funds: $ 10,697
Abstract: Heavy metals pollution from industries such as mining, which is one of Alaska's main industries, can cause toxic effects in aquatic organisms. In order to avoid those, it is recommendable to treat industrial wastewaters onsite before discharge. Biosorption, using waste biomass from other industries as sorbent materials, can be a cost effective metal removal technique. So far, very little research has been performed on citrus peels, in spite of their great potential as biosorbents. Prior research by the PI's research group has shown that citrus peels have a high metal binding capacity due to their pectin content.
The proposed research will investigate the feasibility of using citrus peels through multiple adsorption-desorption cycles. Laboratory experiments will be performed to study desorption kinetics and equilibrium in small scale batch reactors. To facilitate transition to industrial applications, adsorption and desorption will also be studied in packed bed columns. Mathematical models will be developed to describe kinetics for batch desorption and breakthrough curves in packed bed columns. To date, limited or no information is available in the literature on both modeling desorption kinetics and mass transfer limitations in packed bed columns; the proposed research will close those gaps. The economic viability of regenerating the biosorbents through desorption as opposed to their disposal after adsorption will be evaluated. The study will include the treatment of actual mine tailings wastewater in packed bed columns with citrus peel sorbents to test whether heavy metals can be completely removed. Overall, the project will evaluate the feasibility of using citrus peel biosorbents to remove heavy metals in packed bed columns with multiple adsorption-desorption cycles with respect to effluent quality, regeneration and reuse potential, and economic aspects.
Progress/Completion Report, 2010, PDF