Optimization of Congo red dye adsorption with water hyacinth biomass adsorbent using response surface methodology

Abstract

Importance of the work: Water hyacinth biomass has potential as a sustainable adsorbent
for Congo red (CR) removal, addressing agricultural waste utilization and dye pollution.
Objectives: To optimize and model CR removal efficiency using water hyacinth biomass
under varying adsorbent dose, dye concentration and pH.
Materials and Methods: Water hyacinth biomass was tested for CR removal using
adsorption experiments. Response surface methodology (RSM) with Box-Behnken
designs (17 experiments) was used to optimize the adsorbent dose, initial dye
concentration and pH.
Results: Optimal adsorption achieved 94.76% removal efficiency, closely matching the
predicted 98.74%. The mathematical model (developed using Design Expert v8.0.3)
demonstrated a 4.03% deviation, confirming parameter optimization significantly
(p < 0.05) impacted adsorption.
Main finding: Water hyacinth biomass was an efficient and eco-friendly adsorbent
for CR. The results demonstrated that RSM was an appropriate and reliable tool for
optimizing the efficiency of water hyacinth biomass as an adsorbent for CR, contributing
to sustainable pollution control.