Removal of metaldehyde and acetamiprid by extracted cellulose from biomass incorporated with copper after acetylation

Abstract

The presence of pesticides in water have reached to an alarming level in some parts of the world and have caused deteriorating effects on human health. Reclamation of portable water from such contaminants have become mandatory. Scientists around the world are trying to devise new methods of water purification. The target can be achieved either by limiting the use of pesticides for agriculture purposes or by devising unique methods for their recoveries from contaminated water. In this context, herein cellulose has been extracted from Populus nigra, subjected to acetylation using acetic acid in the acidic medium (sulfuric acid). The modified acetylated cellulose was treated with Cu-based salt to enable the metallic combination. The prepared sorbent was characterized by UV, SEM, EDX, XRD, and FTIR techniques. Two insecticides; metaldehyde and acetamiprid in synthetic waste-water solution were subjected for adsorption on the modified sorbent in a series of experiments to evaluate the impact of contact time, sorbent dosage, pH, and temperature. Optimum conditions established in a series of experiments such as 80 and 60 min of contact time for acetamiprid and metaldehyde respectively, pH of 8 and 9 (slightly basic) correspondingly for the mentioned pesticides, and a 0.08 g adsorbent dosage were used in the estimation of kinetics and isothermal parameters. The kinetic data successfully followed the pseudo-second-order kinetic model whereas, the isothermal data was found to be best fitted by Langmuir isotherm model in the case of acetamiprid and by Freundlich in the case of metaldehyde. The regeneration study was performed for both the pesticides showing more than 70 % removal capabilities of fabricated adsorbent after three consecutive cycles. The prepared adsorbent could be a better alternative of commercial activated carbon however, further experiments are encouraged to investigate the full environmental application spectrum of the fabricated sorbent.