Efficient removal of organophosphorus pesticides from wastewater using polyethylenimine-modified fabrics

Pesticides are organic toxic materials and, nowadays, their removal from water is globally required. Herein, modified natural fabrics based on cotton and wool were designed to eliminate pesticides from water. Firstly, fabrics were modified with polyethyleneimine (PEI) to increase the active sites. Modification of fabrics was affirmed by electron microscopy and infrared spectroscopy. PEI-modified fabrics were then applied in the elimination of pirimiphos-methyl and monocrotophos pesticides. The adsorption reactions of pesticides onto fabrics were fitted well to pseudo-second order and the rate of reaction was accelerated by PEI-modification. Adsorption profiles of pesticides have complied with Langmuir isotherm. Maximum adsorption capacities of pesticides were significantly grown from 131.6 to 172.4 mg/g to 333.3-454.6 mg/g for cotton and from 153.4 to 200.0 mg/g to 500.0-625.0 mg/g for wool fabrics, after modification with 10% PEI. A Linear correlation between adsorption capacities and nitrogen contents was observed. Despite the reduction in adsorption capacities detected by recovering process due to the lowering of nitrogen contents, adsorption capacities results were quite high after fifth recovering cycles. Therefore, the prepared PEI-modified fabrics are considered as a safely applicable and highly adsorptive material for the efficient elimination of pesticides from water with a quite good reusability.