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

https://doi.org/10.1016/j.jece.2021.106095Get rights and content

Highlights

  • Industrial wastewater (IW) was treated by supercritical water technology.

  • The influence of process such as temperature and flow rate was evaluated.

  • Under optimized conditions, a TOC reduction of 88.4% was achieved for IW samples.

  • H2 production stood out over other gases (CO2, CO, CH4, C2H6, C2H4).

  • A significant reduction in the phytotoxicity of the treated IW was observed.

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.

Introduction

One of the major challenges in the treatment of industrial wastewater is to carry out rapid and efficient degradation of organic pollutants combined with the lowest possible demand for energy and capital. In particular, the treatment of pharmaceutical residues (e.g., hormones, antibiotics, anti-inflammatories, etc.) using traditional methods (e.g., biological, sorption, advanced oxidation processes, hydrolytic degradation, etc.) has shown low efficiency not ensuring its total degradation [1], [2]. After conventional treatments, the hazardous character of the molecules persists over long periods of time over the biome on the receiving ecosystem [3], [4].

Hormones, especially, are known to cause endocrine disruption that may affect the ecosystem [4]. Steroid hormones, such as estrogens, androgens, progestogens, glucocorticoids, and mineralocorticoids, are frequently found in the environment [5], [6]. Even at low levels, hormones may affect the growth, development, and reproduction of aquatic organisms [7], [8]. Generally, the presence of these contaminants in the environment is connected to domestic sewage disposal, agricultural runoffs, and industrial effluents [9]. Traditional technologies used to treat wastewaters include physical-chemical methods such as coagulation and flocculation followed by sedimentation of the sludge. Several treatment process can also be combined to achieve more effectiveness. Due to the chemical stability and low biodegradability of several organic pollutants, e.g. hormones, biological treatments have been usually coupled as a complementary treatment stage to in attempt to overcome the reduced efficiency of conventional treatment methods [10], [11], [12]. Therefore, chemical treatments carried out in the presence of highly oxidizing agents, e.g., advanced oxidation processes, have been widely proposed to degrade hormones [13]. Fenton (Fe2+/H2O2) oxidation process of effluent from a wastewater treatment plant (WWTP) could remove 84.7% of 17α-ethinylestradiol after 24 h in a bath system [14]. Photo-Fenton (Fe2+/H2O2/ultraviolet radiation) oxidation of effluent from a municipal WWTP could obtain 62% removal of estrogenic activity after 120 min in a bath system [15]. Oxidation by ozonation (2 mg min L−1) of effluent from a WWTP removed 47–99% of progestogens at 5 °C [16]. Due to the necessity of expensive reagents, co-generation of toxic chemical sludge, and the possibility of generation of hazardous intermediaries, it is necessary to propose and develop new technologies to treat persistent organic pollutants such as hormones [17].

Treatment processes involving supercritical water (SCW) have been gaining interest over the last 25 years. The SCW technology can be defined as processes that employ water above its critical point (374 °C and 221 bar), which is a dense gas, with good transport and solvation properties, capable of treating most organic compounds [18], [19]. In this sense, the first commercial supercritical water plant for sludge oxidation, implemented in 2001, was successfully demonstrated in Harlingen (Texas, USA), proving to be an effective and economical process that met all federal and state guidelines of the USA [20]. Typically, this treatment process has been efficient in the degradation of organic pollutants, requiring low spatial time and generating gases of great industrial interest such as hydrogen, methane, and/or syngas, which is considered an advantage in face of the growing global demand for energy from renewable sources [21].

Nowadays, concerning recalcitrant pharmaceutical molecules, some studies have investigated the treatment of synthetic and/or industrial wastewaters. Falamarzian and co-workers [22], showed the degradation of carbamazepine, metoprolol, and sulfamethoxazole using a batch reactor with SCW. Likewise, other studies have considered the treatment of analgesics and antibiotics with or without the addition of auxiliary oxidizing agents (e.g., H2O2) [23], [24]. However, most of these studies are batch processes, which makes them less viable for large-scale operations. In this sense, Mylapilli and Reddy [25], treated industrial pharmaceutical wastewater containing analgesics, antibiotics, and antipyretics using a continuous reactor. Although the high complexity of the industrial effluent, the treatment results were positive and significant removal of conventional and pharmaceuticals pollutants has been reported. Recognized as a promising alternative to traditional industrial wastewater treatment processes, the growth of reports involving treatment technologies with SCW is notorious [26], [27]. However, to the best of our knowledge, not many literature reports are available based on the treatment of hormones in effluent obtained directly from the pharmaceutical industry using continuous flow SCW processes.

In this current study, we presented the treatment of synthetic wastewater (SW) and industrial wastewater (IW), both containing hormones, by a non-catalytic SCW process under continuous flow. For this, the preliminary assessment was performed using SW, which was prepared from the commercial desogestrel. This is one hazardous pollutant among several progestogen hormones in the light of the ecotoxicology research [28]. Beyond, desogestrel is widely used in Brazil, and it is one of the main products in the regional pharmaceutical industry portfolio [29]. Then, tests with IW treatment were carried out. Both treated and untreated samples of SW and IW were characterized to evaluate the efficiency of the process in reducing the pollutant load and toxicity. In addition, the composition of the gaseous phase produced in the process was determined and it allowed to quantify the generation of hydrogen among other gases of possible industrial interest by volume of treated wastewater. Based on the results, the proposed treatment has revealed great potential, enabling the reuse of fit-for-purpose water or safe disposal in the appropriate receptor hydric bodies.

Section snippets

Wastewater samples

Samples of the synthetic wastewater (SW) and industrial wastewater (IW), both containing hormones, were evaluated. SW was prepared using 1 g L−1 of commercial tablets of drug desogestrel (Sandoz®, 0.075 mg; Brazil) crushed and diluted in ultrapure water to achieve the equivalent of a 1.25 mg L−1 desogestrel solution. IW was supplied by a pharmaceutical industry located in the State of Goiás, Brazil. The IW sample was collected at the endpoint of the storage tank without prior treatment. Thus,

Results of TOC and HPLC analysis

The occurrence of hormonal contaminants in the water bodies is an issue of major concern because it affects human health and the environment. For this reason, we employed the SCW process as a powerful treatment for hormones in wastewater. At first, exploratory experimental tests using SW were carried out to evaluate the effect of feed flow rate and reactor temperature on the treatment efficiency in terms of TOC reduction and desogestrel degradation.

The results of TOC reduction for samples of SW

Conclusion

Hormonal wastewater samples (synthetic and industrial) were treated via SCW process. Temperature had a greater influence than the flow rate on both TOC reduction and H2 generation. For the SW samples, the SCW process achieved a TOC reduction higher than 80% for most feed flow rate conditions at 700 °C. For the IW samples, a reduction of 88.4% on the initial TOC value was achieved at a temperature of 700 °C.

The mass spectrometry analysis did not show the generation of new compounds in the SCW

CRediT authorship contribution statement

Thiago S.S. Ribeiro: Conceptualization, Methodology (design and development of tests), Validation, Investigation, Data curation, Writing – original draft. Lucas C. Mourão: Methodology (development of tests), Validation, Data curation, Writing – original draft. Guilherme B.M. Souza: Investigation, Writing – original draft, Visualization. Isabela M. Dias: Investigation, Writing – original draft, Visualization Laiane A. Andrade: Investigation, Data curation (statistical analysis), Writing – review

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors gratefully acknowledge the financial support from Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq (Grants 407158/2013-8 and 431642/2016-8). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES – Brasil – Finance Code 001. In addition, the authors would like to thank the following partners labs: Central Analítica do Instituto de Química da UFG; Laboratório de Métodos de Extração e Separação – LAMES/UFG;

References (56)

  • H. Yarahmadi et al.

    Effect of temperature on oxidation kinetics of testosterone and progestogens by ozone

    J. Water Process Eng.

    (2019)
  • M.B. Ahmed et al.

    Progress in the biological and chemical treatment technologies for emerging contaminant removal from wastewater: a critical review

    J. Hazard. Mater.

    (2017)
  • J.W. Griffith et al.

    The first commercial supercritical water oxidation sludge processing plant

    Waste Manag.

    (2002)
  • A.B.A. Ibrahim et al.

    Supercritical water gasification of wastewater sludge for hydrogen production

    Int. J. Hydrog. Energy

    (2019)
  • S. Falamarzian et al.

    Catalytic hydrothermal treatment of pharmaceutical wastewater using sub- and supercritical water reactions

    J. Supercrit. Fluids

    (2014)
  • S. Stavbar et al.

    Sub- and super-critical water oxidation of wastewater containing amoxicillin and ciprofloxacin

    J. Supercrit. Fluids

    (2017)
  • S.V.P. Mylapilli et al.

    Sub and supercritical water oxidation of pharmaceutical wastewater

    J. Environ. Chem. Eng.

    (2019)
  • J. Chen et al.

    Sub- and super-critical water oxidation of wastewater containing organic and heavy metallic pollutants and recovery of superfine metallic particles

    J. Environ. Chem. Eng.

    (2016)
  • S. Top et al.

    Treatment of hospital wastewater by supercritical water oxidation process

    Water Res.

    (2020)
  • A.P.J. Scandelai et al.

    Combined processes of ozonation and supercritical water oxidation for landfill leachate degradation

    Waste Manag.

    (2018)
  • P. Casademont et al.

    Gasification of olive oil mill waste by supercritical water in a continuous reactor

    J. Supercrit. Fluids

    (2018)
  • S.N. Reddy et al.

    Supercritical water gasification of biomass for hydrogen production

    Int. J. Hydrog. Energy

    (2014)
  • R.F. Susanti et al.

    Supercritical water gasification for hydrogen production

    Supercrit. Fluid Technol. Energy Environ. Appl.

    (2014)
  • Y. Gong et al.

    Gasification of landfill leachate in supercritical water: effects on hydrogen yield and tar formation

    Int. J. Hydrog. Energy

    (2018)
  • W. Qin et al.

    Chemical looping reforming of ethanol-containing organic wastewater for high ratio H2/CO syngas with iron-based oxygen carrier

    Int. J. Hydrog. Energy

    (2018)
  • Q. Liu et al.

    High H2/CO ratio syngas production from chemical looping co-gasification of biomass and polyethylene with CaO/Fe2O3 oxygen carrier

    Energy Convers. Manag.

    (2019)
  • S. Sarrade et al.

    Overview on corrosion in supercritical fluids

    J. Supercrit. Fluids

    (2017)
  • M. Pan et al.

    Phytotoxicity of veterinary antibiotics to seed germination and root elongation of crops

    Ecotoxicol. Environ. Saf.

    (2016)
  • Cited by (14)

    • Highly efficient amino-functionalized aluminum-based metal organic frameworks mesoporous nanorods for selective extraction of hydrocortisone in pharmaceutical wastewater

      2022, Journal of Pharmaceutical and Biomedical Analysis
      Citation Excerpt :

      Environmental steroid hormones include androgens, estrogens and adrenal cortex hormones, which often enter the environment through domestic sewage discharges and industrial effluents [3]. In contrast to domestic sewage, industrial effluents have the characteristics of complex composition and great harm [4]. Especially, the steroid hormone pharmaceutical wastewater, is composed of a variety of intermediates, by-products and products with strong biological activity [5].

    View all citing articles on Scopus
    View full text