Mycosorption of copper by Aspergillus terreus SJP02: process optimization and underlying mechanism

Copper, a naturally occurring element in the Earth's crust and an essential micronutrient, is widely used in various industries. However, excessive exposure of Cu²⁺ions often resulting from contaminated drinking water, food and personal health care products can harm human health by impacting the liver, heart, digestive and nervous system. The present study revealed high Cu²⁺ removal potential of Aspergillus terreus SJP02 isolated from metal contaminated industrial sites. The mycosorbent demonstrated maximum sorption capacity of 11.45 ± 0.2 mg g^-1 in 120 min. Acid digestion studies suggested adsorption as primary mechanism (86.79%) for removal of Cu²⁺. FE-SEM-EDX analysis confirmed deposition of Cu²⁺ on fungal biomass. FTIR analysis showed presence of various functional groups of proteins and polysaccharides which would have been involved in the adsorption Cu²⁺. Various adsorption isotherms were used to analyze type and bonding between adsorbate and mycosorbent. Pseudo- first and second order were applied to understand the correlation in time course data, rate constant, and kinetic parameters. Langmuir isotherm showed maximum Cu²⁺ sorption capacity of 11.35 mg g^-1. The experimental results correlated with the tested isotherm and kinetic models. The simultaneous removal of Cu²⁺and Zn²⁺ ions revealed preferential uptake of Cu²⁺ over Zn²⁺ ions by the mycosorbent. Notably, present study demonstrated better sorption capacity in significantly shorter equilibration time in comparison to previous reports and suggests that A. terreus SJP02 holds strong potential for future industrial-scale mycoremediation of Cu²⁺ contaminated wastewater.