Removal of emerging contaminants from wastewater using nanofiltration for its subsequent reuse: Full–scale pilot plant
Graphical abstract
Introduction
Earth is continually being polluted with numerous chemical substances of natural and anthropogenic origin. The exponential growth of the population and the rise in the use of these substances has led to an increase in their concentrations in wastewater, hence in the environment (Sarkar et al., 2018).
Many of these pollutants have not been subjected to a suitable assessment of the potential environmental risks and impacts that they may have on ecosystems and living beings, including their effects on human health (Riva et al., 2018a).
Among the substances detected in WWTP effluents it is possible to detect antibiotics (amoxicillin and penicillin G). Antibiotics may have a considerable environmental impact even at low concentrations, as they can cause resistance in bacteria and other microorganisms (Lu et al., 2016), including Streptococcus pneumoniae, which is classified as “penicillin-non-susceptible” in the World Health Organization (WHO) list of priority pathogens for R&D (WHO, 2017). Caffeine, theobromine and theophylline, which belong to the family of stimulants, have also been detected in quite significant concentrations in both wastewater and receiving waters (Buchberger, 2011, Senta et al., 2015), especially in some Mediterranean river basins where WWTP effluents (Rabiet et al, 2006) constitute a high percentage of the total river flow, especially in periods of drought (Köck-Schulmeyer et al., 2011).
Different types of treatments are currently being tested to effectively remove these emerging contaminants (EC) from wastewater, with the lowest possible economic cost, before being discharged into ecosystems. The technologies that are currently being used include membrane processes, in particular, nanofiltration and reverse osmosis. Both technologies have been very effective in the removal of different organic compounds (Kim et al., 2018), as they even permit the respective separation of divalent and monovalent ions from wastewater.
Besides, the scarcity of water in certain areas of the world (Mediterranean countries among them) leads to the need to regenerate and reuse water from secondary effluents. European landfill regulations (Directive 91/271/EEC) regulate the organic load that WWTP effluents must have, but guides about their possible reuse are missing. There is no specific legislation in Europe on the reuse of treated water. In Spain, the quality of reclaimed water is regulated by Royal Decree 1620/2007, of 7 December, establishing the legal framework for the reuse of treated water. In order to reuse reclaimed water, Spanish legislation requires that quality water obtained at the WWTP have to be in accordance with its intended use. However, the legislation on discharges and reuse do not takes into consideration emerging contaminants, as they are not among the priority substances in the field of water policy (Directive, 2013/39/EU). These substances will be probably included in the pertinent legislation in the future. For all these reasons, to avoid the problems that they may cause in the meantime and taking into account the effectiveness and relative low cost of nanofiltration membranes, they were chosen. Previous studies demonstrated that nanofiltration as tertiary treatment is a viable method for removing trace pharmaceutically (García-Ivars et al., 2017), but it is necessary to know at higher concentrations of emerging contaminants, real wastewater in pilot plant and more time than those studied. The present study shows an open circuit (72 h) with high concentrations of the chosen contaminants. The removal of emerging contaminants belonging to the family of stimulants (caffeine, theobromine and theophylline) and the family of antibiotics (amoxicillin and penicillin G) present in municipal wastewater via the use of nanofiltration as a tertiary treatment at a WWTP was studied in this work, in order to test the effectiveness of this technology for the reuse of the effluent.
Section snippets
Equipment used
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Medina Sidonia WWTP
The plant chosen to carry out the experiments was located in the town of Medina Sidonia, a municipality in Southern Spain, in the centre of the province of Cádiz, Andalusia. It currently has a population of 11.741 inhabitants. Its WWTP is equipped to treat the wastewater from a population centre of 17.599 hab-eq and can achieve a flow rate of 2.223 m3·day−1.
There are two treatment lines: water and sludge. As at the majority of the existing WWTPs in Spain, the water line of
Characterization of the influent and effluent at Medina Sidonia WWTP
The influent and effluent at Medina Sidonia WWTP were characterized between January 2017 and January 2018. Table 3 shows the average, minimum and maximum values of the different parameters for the 12 samplings performed, as well as their standard deviations. In general, the characterization of the influent wastewater reaching the plant indicates that it is comparable to medium-polluted municipal wastewater (Egea-Corbacho, 2019).
Some parameters (Chemical Oxygen Demand (COD), turbidity,
Conclusions
The study of tertiary treatment by nanofiltration for the removal of stimulants and antibiotics in a pilot plant was found to be both satisfactory and highly promising, achieving complete removal of the contaminants under study. Likewise, the viability of the nanofiltration in obtaining a permeate water with suitable quality to be put to all possible reuses has been demonstrated. These reuses may vary from residential or urban irrigation (e.g. irrigation of green areas or street cleaning),
Acknowledgments
We thank WWTP's technician of Medina Sidonia, Juan Carlos, for all his work and we also thank the Global Medina company for the facilities.
References (38)
- et al.
Acid mine drainage treatment by nanofiltration: a study of membrane fouling, chemical cleaning, and membrane ageing
Separ. Purif. Technol.
(2018) - et al.
Hospital wastewater treatment with pilot-scale pulsed corona discharge for removal of pharmaceutical residues
J of Environ Chem Eng
(2018) - et al.
Antibiotic removal from wastewaters: the ozonation of amoxicillin
J. Hazard Mater.
(2005) Current approaches to trace analysis of pharmaceuticals and personal care products in the environment
J. Chromatogr. A
(2011)- et al.
Removal of emerging contaminants from wastewater through pilot plants using intermittent sand/coke filters for its subsequent reuse
Sci. Total Environ.
(2019) - et al.
Selective nitrate removal from groundwater using a hybrid nanofiltration–reverse osmosis filtration scheme
Chem. Eng. J.
(2015) - et al.
Nanofiltration as tertiary treatment method for removing trace pharmaceutically active compounds in wastewater from wastewater treatment plants
Water Res.
(2017) - et al.
Optimal design of spacers in reverse osmosis
Separ. Purif. Technol.
(2018) - et al.
Removal of contaminants of emerging concern by membranes in water and wastewater: a review
Chem. Eng. J.
(2018) - et al.
Determination of penicillin G and 17 its degradation products in a penicillin production wastewater treatment plant and the receiving river
Water Res.
(2008)
Simultaneous removal of chemical oxygen demand, turbidity and hardness from biologically treated citric acid wastewater by electrochemical oxidation for reuse
Separ. Purif. Technol.
Feasibility of antibiotic and sulfate ions separation from wastewater using electrodialysis with ultrafiltration membrane
J. Clean. Prod.
Membrane fouling in whey processing and subsequent cleaning with ultrasounds for a more sustainable process
J. Clean. Prod.
A review on the occurrence of micropollutants in the aquatic environment and their fate and removal during wastewater treatment
Sci. Total Environ.
A preliminary nationwide survey of the presence of emerging contaminants in drinking and source waters in Brazil
Sci. Total Environ.
Membranes technology used in water treatment: chemical, microbiological and ecotoxicological analysis
Sci. Total Environ.
Monitoring emerging contaminants in the drinking water of Milan and assessment of the human risk
Int. J. Hyg Environ. Health
Designer carbon nanotubes for contaminant removal in water and wastewater: a critical review
Sci. Total Environ.
Wastewater analysis to monitor use of caffeine and nicotine and evaluation of their metabolites as biomarkers for population size assessment
Water Res.
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