Optimization of copper(II) biosorption onto waste Gossypium hirsutum seed microwave-biochar using RSM

Abstract

Biochar was prepared from waste Gossypium hirsutum seeds using microwave activation and were used as adsorbent for copper (II) removal from aqueous solution. The main and interactive properties of biochar dosage (1–3 g/L), initial copper (II) concentration (5–15 mg/ L), pH (2–12) and temperature (20–40°C) were examined using Box– Behnken surface methodology. The statistical analysis indicated good fit of the experimental data with correlation coefficient (R2=0.9997), F–value (3929.31), coefficient of variation (0.61), and adequate precision (200.89). Nonlinear optimization indicated that 100% removal of copper could be achievable at biochar dosage 2.1 g/L, initial copper concentration 10.72 mg/L, pH 8.2, and temperature 28.69°C.