Efficient adsorption of pesticides by porous organic polymers based on imine/aminal linkages

Abstract

Porous organic polymers (POPs) are promising materials for pesticide adsorption from wastewater due to their high surface area and tunable porous structure. MPT-TPA-POPs were synthesized in green solvents using inexpensive diamines and dialdehyde monomers to form imine and aminal linkages. This study investigated for the first time the adsorption and removal effects of pesticides Forchlorfenuron (CPPU) and Acetamiprid (ACE) using MPA-TPA-POPs adsorbent. FTIR, SEM, EDS, BET, and XPS analyses were utilized to examine changes in functional groups, morphology, elemental composition, specific surface area, and pore volume of MPT-TPA-POPs before and after CPPU and ACE adsorption. At an initial concentration of 50 mg/L, with a dosage of 0.5 g/L, a pH of 7, a temperature of 298 K, and an adsorption time of 120 min, the maximum removal rates for CPPU and ACE are achieved at 99.94 % and 68.44 %, respectively. The quasi-second-order kinetic and Langmuir isotherm model were deemed more appropriate for accurately describing this adsorption process. Thermodynamically, the adsorption process was observed to be spontaneous and exothermic. Simultaneously, during cyclic adsorption-desorption experiments, the adsorption capacity of MPT-TPA-POPs material showed no significant decline even after six cycles. The findings of this research suggest that MPT-TPA-POPs can act as a green, eco-friendly, cost-efficient, and effective adsorbent for eliminating CPPU and ACE pesticides from water, offering an economically feasible approach to pesticide removal.