Effective adsorption of Cu(II) ions on sustainable adsorbent derived from mixed biomass (Aspergillus campestris and agro waste): Optimization, isotherm and kinetics study

In this investigation, Cu(II) ions were removed from the synthetic solution using the mixed biomass [Aspergillus campestris and two forms of Delonix regia seed (raw and acid treated Delonix regia seed)] as adsorbent. The copper resistant fungal species was isolated from industrial effluent in the Erode city, India. The safe strain was identified as Aspergillus campestris by sequential investigation of 18S rRNA. The characteristic investigations of mixed adsorbent materials were examined by FTIR, SEM, EDX examination. Adsorption analysis was done with respect to different reaction parameters and their optimum values were determined as follows: mixed adsorbent dosage 1.0 g/L; pH - 6.0; contact time - 30 min; temperature - 303 K. The isotherm and kinetic investigations were performed with four distinctive isotherm models and three kinetic models. The adsorption isotherm investigation demonstrates that equilibrium data was best fitted to Freundlich isotherm model which explains the present adsorption study was multilayer and their surface was heterogeneous in nature. The maximum monolayer adsorption capacity (q(m)) value of the mixed biomass of Aspergillus campestris with raw and surface modified Delonix regia seeds were found to be 62.02 mg/g and 66.9 mg/g respectively. The kinetic investigation was fitted with pseudo first-order model. Thermodynamic parameters affirmed that evacuation of Cu(II) particles was a plausible, unconstrained and exothermic in nature. This examination demonstrates a practical procedure for the plan of mixed biomass and features the extraordinary potential in wastewater treatment.