The experiments were performed by different concentrations of adsorbent, which showed that the removal efficiency increased with an increase in adsorbent concentration up to 0.5 g in 25 ml solution. After a very slow increase in removal percentage, it was found that the increase in adsorbent of more than 0.5 g dose did not affect the removal percentage significantly.
This may be presumed that the availability of active sites on the nanocomposite is decreasing at higher doses of sorbents (>0.5 g). The total active surface area increases by increasing composite dosage. At the same time, due to increasing amount of sorbent, the sorbent–sorbent interactions are more dominating than sorbate–sorbent interactions [37,38]. Since the most effective removal of permethrine was observed with 0.5 g of CS–ZnONPs composite, the other experiments were performed in this concentration.