2024 AIChE Annual Meeting

Effect of Keratin on Adsorption of Copper Ions Using Sodium Alginate

Wastewater containing heavy metals are a byproduct of industrial processes in a wide variety of sectors, not limited to construction, electronics, and mining. Heavy metals are toxic, and not only pose a threat to human health, but to the health of ecosystems and the environment. Many different methods to remove heavy metals from waste streams have been developed to remove heavy metals from water, including chemical precipitation, membrane filtration, ion exchange, and adsorption, among others. Of these methods, adsorption is often considered an economically viable and environmentally-friendly method to remove heavy metals from solution.

One type of adsorbent is a biosorbent, which is made from organic compounds to adsorb metal ions in wastewater. Two bioadsorbents that have received recent attention are adsorbents made with alginate, a biopolymer derived from seaweed, and keratin, a protein found naturally in hair, wool, and feathers, among other sources. These two biopolymers are high in carboxyl and hydroxyl groups, which bind metal ions, allowing for the facilitation of adsorption of metal ions. Additionally, these materials are sustainable, cheap, nontoxic, widely-available, and biodegradable.

This project investigated the adsorption of copper (Cu) ions as a representative heavy metal from water on keratin-alginate composite bioadsorbents. The effects of keratin to alginate mass ratios were investigated with consideration to both adsorption capacity and adsorption kinetics. It was found that bioadsorbents with a keratin /alginate mass ratio were detrimental to adsorption capacity. Pure sodium alginate bioadsorbents had the highest adsorption capacities in this study for copper ions of up to 138 mg / g. The kinetics of adsorption of the bioadsorbents made in this study were comparable to each other.