Fixed-bed adsorption kinetics study of auramine O dye on non-imprinted polymers based on a real-time monitoring system

Abstract

Fixed-bed adsorption technology is one of the most important methods for removing pollutants like auramine O (AO) dye from environmental water. Traditionally, breakthrough curves are derived from laborious manual processes including effluent collection, sampling, and offline analysis, prone to significant errors and data scarcity. Herein, a fiber-optic sensing technique for online, real-time monitoring was applied to plot breakthrough curves during fixed-bed adsorption, addressing this inherent problem. A synthesized non-imprinted polymers (NIPs) adsorbent achieved adsorption capacity comparable to that of molecularly imprinted polymers. The adsorption capacity was 203.99 mg/g at a feed concentration of 15 mg/L, a feed flow rate of 3 mL/min, an adsorbent mass of 30 mg, a solution pH of 3, and a particle size range of 38–75 μm. Kinetic studies showed that the Dose-Response model was more suitable for predicting the adsorption of AO on NIPs. The adsorption capacity did not change significantly (RSD = 2.39 %) in 30 cycles of regeneration experiments on the NIPs fixed-bed. The technique offers the advantages of online detection and real-time monitoring, making it suitable for application in the adsorption and removal processes of environmental pollutants.