Removal of Pharmaceuticals and Illicit Drugs from Wastewater Due to Ferric Dosing in Sewers

Abstract

Ferric (Fe3+) salt dosing is an efficient sulfide control strategy in the sewer network, with potential for multiple benefits including phosphorus removal in the biological reactors and sulfide emission control in the anaerobic digesters of wastewater treatment plant (WWTP). This paper extends the knowledge on the benefit of iron dosing by exploring its impact on the fate of organic micropollutants (MPs) in the wastewater using sewer reactors simulating a rising main sewer pipe. The sulfide produced by the sewer biofilms reacted with Fe3+ forming black colored iron sulfide (FeS). Among the selected MPs, morphine, methadone, and atenolol had >90% initial rapid removal within 5 min of ferric dosing in the sewer reactor. The ultimate removal after 6 h of retention time in the reactor reached 93-97%. Other compounds, ketamine, codeine, carbamazepine, and acesulfame had 30-70% concentration decrease. The ultimate removal varied between 35 and 70% depending on the biodegradability of those MPs. In contrast, paracetamol had no initial removal. The rapid removal of MPs was likely due to adsorption to the FeS surface, which is further confirmed by batch tests with different FeS concentrations. The results showed a direct relationship between the removal of MPs and FeS concentration. The transformation kinetics of these compounds in the reactor without Fe3+ dosing is in good agreement with biodegradation associated with the sewer biofilms in the reactor. This study revealed a significant additional benefit of dosing ferric salts in sewers, that is, the removal of MPs before the sewage enters the WWTP.

Comparative removal of imidacloprid, bisphenol‐S, and azithromycin with ferrate and FeCl3 and assessment of the resulting toxicity

“…37 By adjusting the concentration of Fe 3+ to 10 mg L -1 in sewer reactors, more than 90% of morphine methadone and atenolol were removed from the wastewater. 38 Although both ferrate and ferric chloride have been researched and/or used for water and wastewater treatment, direct comparisons of the performance between the two chemicals are limited, especially in the context of the treatment of EMPs. Thus, this is one of objectives of this study.…”

“…One researcher disclosed that 79% of galaxolide and 83% of tonalide were removed from the hospital effluent at the dose of 25 mg FeCl 3 L ‐1 and 90% of nonyphenol and 70% of diethylhexylphthalate (DEHP) were removed from the landfill leachates by dosing 100 mg FeCl 3 L ‐1 37 . By adjusting the concentration of Fe 3+ to 10 mg L ‐1 in sewer reactors, more than 90% of morphine methadone and atenolol were removed from the wastewater 38 . Although both ferrate and ferric chloride have been researched and/or used for water and wastewater treatment, direct comparisons of the performance between the two chemicals are limited, especially in the context of the treatment of EMPs.…”

Inhibition of staphylococci and S. aureus in wastewater by ferrates and electrochemical methods

“…In community, S. aureus can be easily transferred from carriers or infected persons via direct contact and specific carriers (Stepanović et al, 2008) as it can survive in different environments, including wastewater. Nowadays, many scientific studies deal with chemical and biological elimination of micropollutants such as X-ray substances, antibiotics, psychoactive pharmaceuticals, drugs and resistant types of microorganisms in municipal wastewater (Golovko et al, 2014;Mackuľak et al, 2015a;Verlicchi and Zambello, 2015;Iakovides et al, 2019;Kulandaivelu et al, 2019). Wastewater from point sources, e.g.…”

“…health care institutions, are intensively studied to find biological and chemical methods for wastewater treatment such as membrane bioreactors, Fenton reaction, ozonization, heteroge-neous catalysis, boron-doped diamond electrodes (BDDE), application of ferrates etc. (Verlicchi and Zambello, 2015;Mackuľak et al, 2015aMackuľak et al, , 2015bMackuľak et al, , 2016Michael-Kordatou et al, 2018;Kulandaivelu et al, 2019). These techniques show significant degradation of various groups of pharmaceuticals and illegal drugs.…”

Investigating the fate of organic micropollutants due to the dosing of iron salt or iron rich drinking water treatment sludge in urban wastewater system

“…In addition to these benefits, FeS formation had another potential additional benefit of removing organic MPs in the sewer network. It is known from our previous chapter that MPs will be removed due to the dosing of Fe salt in the rising main sewer condition, likely due to the formation of FeS particles 215 . Considering the iron concentration and FeS formation potential of Fe-DWTS, it might contribute to the removal of MPs from wastewater while being discharged into the sewers.…”