Wet Peroxide Oxidation of Paracetamol Using Acid Activated and Fe/Co-Pillared Clay Catalysts Prepared from Natural Clays

Adriano Santos Silva,Helder T Gomes,Juliana G Sgorlon,Marzhan Seitovna Kalmakhanova,Diaz De Tuesta Jose Luis,Bakytgul Kabykenovna Massalimova

doi:10.3390/catal9090705

Abstract

Many pharmaceuticals have been recently identified at trace levels worldwide in the aquatic environment. Among them, the highly consumed paracetamol (PCM), an analgesic and antipyretic drug, is largely being accumulated in the aquatic environment due to inefficient removal by conventional sewage treatment plants. This work deals with the treatment of PCM, used as a model pharmaceutical contaminant of emerging concern, by catalytic wet peroxide oxidation using clay-based materials as catalysts. The catalysts were prepared from natural clays, extracted from four different deposits using acid-activated treatment, calcination, and pillarization with Fe and Co. Pillared clays show the highest catalytic activity owing to the presence of metals, allowing to remove completely the PCM after 6 h under the following operating conditions: CPCM = 100 mg L−1, CH2O2 = 472 mg L−1, Ccat = 2.5 g L−1, initial pH = 3.5 and T = 80 °C. The prepared materials presented high stability since leached iron was measured at the end of reaction and found to be lower than 0.1 mg L−1.

Highlights

Especially after the development of sophisticated analytical techniques, many pharmaceuticals have been identified at trace levels worldwide in the aquatic environment [1]
Municipal wastewater treatment plants (WWTPs) are considered the main sources of these pollutants as they are not generally prepared to deal with these complex substances, and they are usually ineffective in their complete removal [1,2,3,4]
The preparation of clay-based materials by acid activation and by pillarization leads to an increase of the acidity character and of the specific surface area with respect to the corresponding natural clays

Summary

Introduction

Especially after the development of sophisticated analytical techniques, many pharmaceuticals have been identified at trace levels (ng L−1 –mg L−1 ) worldwide in the aquatic environment [1]. The presence of pharmaceuticals, even in trace concentrations, affects the quality of water and constitutes a risk of toxicity for the ecosystems and living organisms. According to most recent works, the biological effects of low-dose complex micropollutant mixtures are still underestimated [8]. This constitutes a public health problem since pharmaceuticals have even been found in drinking water supplies [9]

Methods

Results

Conclusion