Model Predictive Control Strategy for the Degradation of Pharmaceutically Active Compounds by UV/H2O2 Oxidation Process

Juwon Lee,Eunju Kim,Tae-Mun Hwang,Sook-Hyun Nam,Jae-Wuk Koo

doi:10.3390/w14030385

Abstract

Hydroxyl radical (•OH) scavenging demand can be an indicator that represents the water quality characteristics of raw water. It is one of the key parameters predicting UV/H2O2 system performance and affects the operating parameters. Based on the •OH scavenging demand, we developed a model predictive control strategy to meet the target compound removal efficiency and energy consumption simultaneously. Selected pharmaceutically active compounds (PhACs) were classified into three groups depending on the UV direct photolysis and susceptibility to •OH. Group 1 for photo-susceptible PhACs (acetaminophen, amoxicillin, diclofenac, iopromide, ketoprofen, and sulfamethoxazole); group 2 for PhACs susceptible to both direct photolysis and •OH oxidation (bisphenol A, carbamazepine, ibuprofen, naproxen, ciprofloxacin, and tetracycline); and group 3 for photo-resistant PhACs (atenolol, atrazine, caffeine, and nitrobenzene). The results of modeling to achieve 90% removal of PhACs at N and B plants were as follows. For group 2, the optimized operating parameter ranges were as follow (N plant: UV 510–702 mJ cm−2, H2O2 2.96–3.80 mg L−1, EED 1088–1302 kWh m−3; B plant: UV dose 1179–1397 mJ cm−2, H2O2 dose 3.56–7.44 mg L−1, EED 1712–2085 kWh m−3). It was confirmed that the optimal operating conditions and EED values changed according to the •OH scavenging demand.

Highlights

In recent years, studying the pollution levels in drinking water, especially the presence of pharmaceutical compounds in the environment, has increasingly garnered interest [1]
This study proposed three groups based on the simulated UV dose and H2O2 concentration considering the OH scavenging demand
The optimum UV dose and H2O2 concentration can be determined for a given condition of targeting energy consumption and removal rates

Summary

Introduction

In recent years, studying the pollution levels in drinking water, especially the presence of pharmaceutical compounds in the environment, has increasingly garnered interest [1]. Many studies have found the presence of PhACs in wastewater, which has been identified as a significant source of medicinal substances in drinking water and owing to the intentional and continuous use of water by humans, large quantities of PhACs have been introduced into the environment [3,4]. These substances are known to enter and remain in rivers or lakes, have long periods of biological activity, and act as potential hazards in ecosystems [5]. Most residual pharmaceuticals can be removed efficiently through ozonation, activated carbon adsorption, membrane filtration (e.g., reverse osmosis and nanofiltration), catalytic ozonation, and Fenton oxidation [5,7,8,9,10,11]

Methods

Results

Discussion

Conclusion