Treatment of hormones in wastewater from the pharmaceutical industry by continuous flow supercritical water technology

Abstract

Hormones are bioactive, ubiquitous, and persistent organic molecules that demand effective treatment when released in the environment. However, most conventional treatments are inefficient or not suitable for large-scale applications. This study describes the use of supercritical water (SCW) technology in the degradation of hormones in wastewater from the pharmaceutical industry. Initially, the treatment was developed with synthetic wastewater (SW) containing hormone prepared from commercial desogestrel pills and, later, with real industrial wastewater (IW). All the experimental tests were conducted in a continuous flow reactor in the absence of catalysts. Both liquid and gas phases generated during the process were analyzed by instrumental techniques. The liquid phase was characterized by total organic carbon (TOC), chemical oxygen demand (COD), high-performance liquid chromatography (HPLC), and phytotoxicity assays. The gas phase was characterized by gas chromatography (GC). TOC reductions of SW and IW samples, both treated at 700 °C and feed flow rate of 10 mL min−1 were 87.2% and 88.4%, respectively. Phytotoxicity assays indicated a significant reduction in the toxicity of the IW treated at 700 °C. Thus, considering the gas production, especially hydrogen, and the high toxicity mitigation, the IW treatment via SCW is quite promising.