Special Issue "Urban and Industrial Wastewater Disinfection and Decontamination by Advanced Oxidation Processes (AOPs): Current Issues and Future Trends"

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Wastewater Treatment and Reuse".

Deadline for manuscript submissions: closed (31 October 2020).

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Dr. Stefanos Giannakis
E-Mail Website
Guest Editor
Department of Hydraulics, Energy and Environment, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
Interests: advanced oxidation processes (AOPs) for microbial disinfection (UV/H2O2, fenton, SO42-, and TiO2, O3); photochemistry of natural waters; environmental chemistry and microbiology; solar-based water purification processes
Dr. Ana Rita Lado Ribeiro
E-Mail Website
Guest Editor
Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
Interests: occurrence and distribution of multi-class organic micropollutants in water/wastewater; analytical tools for determination of organic micropollutants; identification of by-products; advanced oxidation processes: membrane technologies
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Jorge Rodríguez-Chueca
E-Mail Website
Guest Editor
Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid (UPM), Madrid, Spain
Interests: water and wastewater treatment; water quality; water management; wastewater reuse; advanced treatments; environmental engineering
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Dynamic changes in our modern lifestyle and the rise of living standards have led to significant modifications to the composition and characteristics of urban effluents. Owning to the high consumption of chemical substances, such as antibiotics, licit and illicit drugs, medical products, cleaning agents, etc., our everyday life and habitats have been converted to a small-scale industrial plant. This evolution, alongside intensified industrial activities to meet consumer demand, has aggravated the problems of wastewater treatment, to a degree beyond the capacity of regular wastewater treatment plants (WWTPs).

The necessity for proper wastewater (WW) treatment calls for novel, sophisticated methods of decontamination prior to its discharge or reuse. Emerging threats such as antibiotic-resistant bacteria (ARB) and the contaminants of emerging concern (chemicals, microplastics) demand efficient, end-of-pipe solutions before their discharge in the environment or reclamation for reuse purposes. As such, advanced oxidation processes (AOPs) have been procured as effective methods for WW disinfection and decontamination.

In the face of the challenges of modern WW treatment and WWTP operation, this Special Issue is devoted to a wholistic approach towards WWTP matters, focusing to the use of AOPs as an effective solution of pre-treatment or a polishing step for urban or industrial WW effluents. The topics dealt within this Issue include the following:

Treatment targets:

  • Typical urban WW microorganisms (bacteria, viruses, protozoa, etc.);
  • The contaminants of emerging concern (CECs), including chemicals and microplastics;
  • Antibiotic resistant bacteria and genes (ARB and ARG).

as defined by the

  • EU Watch List;
  • European One Health Action Plan against antimicrobial resistance (AMR);
  • Swiss FOEN Legislation for Micropollutants;
  • US EPA Emerging Contaminants and Federal Facility Contaminants of Concern;
  • Chinese legislation (GB-18918).

Occurrence and Monitoring Issues:

  • Advances and challenges in analytical chemistry applied to wastewater treatment;
  • Emerging, geographically distinctive/problematic effluents (local case studies).

Wastewater Treatment Methods to be Considered:

  • Advanced Oxidation Processes (AOPs)
    • UV-based technologies (UV/H2O2, UV/Cl, etc.);
    • Fenton and photo-Fenton processes;
    • TiO2 photocatalysis;
    • Sulfate radical-mediated processes (SR-AOPs);
    • Ozone-based processes;
    • Electrochemical AOPs;
    • Ultrasound and plasma treatment;
    • Coupling of AOPs with membranes;
    • Coupling among AOPs (e.g., photo-electro-Fenton, UV/H2O2/O3);
    • Coupling of AOPs with biological treatments (ABOPs).
  • Advances in materials, catalysts, and methods in AOPs for WW treatment:
    • Nano-materials and nano-catalysts;
    • Next-gen TiO2-based derivatives, photo-catalytic membranes;
    • Graphene and graphitic nitride materials.

Dr. Stefanos Giannakis
Dr. Ana Rita Lado Ribeiro
Prof. Dr. Jorge Rodríguez-Chueca
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Advanced oxidation processes (AOPs)
  • UV-driven technologies
  • Solar-based AOPs
  • Photocatalysis
  • Wastewater disinfection
  • Contaminants of emerging concern
  • Antibiotic resistant bacteria (ARB)
  • Antibiotic resistance genes (ARG)
  • Wastewater regeneration

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

Editorial
Urban and Industrial Wastewater Disinfection and Decontamination by Advanced Oxidation Processes (AOPs): Current Issues and Future Trends
Water 2021, 13(4), 560; https://doi.org/10.3390/w13040560 - 23 Feb 2021
Viewed by 677
Abstract
Without any doubt, the 21st century has kick-started a great evolution in all aspects of our everyday life [...] Full article

Research

Jump to: Editorial, Review

Article
A Pilot Study Combining Ultrafiltration with Ozonation for the Treatment of Secondary Urban Wastewater: Organic Micropollutants, Microbial Load and Biological Effects
Water 2020, 12(12), 3458; https://doi.org/10.3390/w12123458 - 09 Dec 2020
Cited by 4 | Viewed by 1382
Abstract
Ozonation followed by ultrafiltration (O3 + UF) was employed at pilot scale for the treatment of secondary urban wastewater, envisaging its safe reuse for crop irrigation. Chemical contaminants of emerging concern (CECs) and priority substances (PSs), microbial load, estrogenic activity, cell viability [...] Read more.
Ozonation followed by ultrafiltration (O3 + UF) was employed at pilot scale for the treatment of secondary urban wastewater, envisaging its safe reuse for crop irrigation. Chemical contaminants of emerging concern (CECs) and priority substances (PSs), microbial load, estrogenic activity, cell viability and cellular metabolic activity were measured before and immediately after O3 + UF treatment. The microbial load was also evaluated after one-week storage of the treated water to assess potential bacteria regrowth. Among the organic micropollutants detected, only citalopram and isoproturon were not removed below the limit of quantification. The treatment was also effective in the reduction in the bacterial loads considering current legislation in water quality for irrigation (i.e., in terms of enterobacteria and nematode eggs). However, after seven days of storage, total heterotrophs regrew to levels close to the initial, with the concomitant increase in the genes 16S rRNA and intI1. The assessment of biological effects revealed similar water quality before and after treatment, meaning that O3 + UF did not produce detectable toxic by-products. Thus, the findings of this study indicate that the wastewater treated with this technology comply with the water quality standards for irrigation, even when stored up to one week, although improvements must be made to minimise microbial overgrowth. Full article
Show Figures

Figure 1

Article
Degradation of Losartan in Fresh Urine by Sonochemical and Photochemical Advanced Oxidation Processes
Water 2020, 12(12), 3398; https://doi.org/10.3390/w12123398 - 03 Dec 2020
Cited by 7 | Viewed by 948
Abstract
In this work, the degradation of the pharmaceutical losartan, in simulated fresh urine (which was considered because urine is the main excretion route for this compound) by sonochemistry and UVC/H2O2 individually, was studied. Initially, special attention was paid to the [...] Read more.
In this work, the degradation of the pharmaceutical losartan, in simulated fresh urine (which was considered because urine is the main excretion route for this compound) by sonochemistry and UVC/H2O2 individually, was studied. Initially, special attention was paid to the degrading action of the processes. Then, theoretical analyses on Fukui function indices, to determine electron-rich regions on the pharmaceutical susceptible to attacks by the hydroxyl radical, were performed. Afterward, the ability of the processes to mineralize losartan and remove the phyto-toxicity was tested. It was found that in the sonochemical treatment, hydroxyl radicals played the main degrading role. In turn, in UVC/H2O2, both the light and hydroxyl radical eliminated the target contaminant. The sonochemical system showed the lowest interference for the elimination of losartan in the fresh urine. It was established that atoms in the imidazole of the contaminant were the moieties most prone to primary transformations by radicals. This was coincident with the initial degradation products coming from the processes action. Although both processes exhibited low mineralizing ability toward losartan, the sonochemical treatment converted losartan into nonphytotoxic products. This research presents relevant results on the elimination of a representative pharmaceutical in fresh urine by two advanced oxidation processes. Full article
Show Figures

Figure 1

Article
Degradation of Hexacyanoferrate (III) from Gold Mining Wastewaters via UV-A/LED Photocatalysis Using Modified TiO2 P25
Water 2020, 12(9), 2531; https://doi.org/10.3390/w12092531 - 10 Sep 2020
Cited by 1 | Viewed by 762
Abstract
The photocatalytic degradation of potassium hexacyanoferrate (III) was assessed in a bench-scale compound parabolic collectors (CPC) reactor assisted with a light-emitting diode (LED) UV-A source emitting at 365 nm, and using a modified TiO2 as a catalyst via the hydrothermal treatment of [...] Read more.
The photocatalytic degradation of potassium hexacyanoferrate (III) was assessed in a bench-scale compound parabolic collectors (CPC) reactor assisted with a light-emitting diode (LED) UV-A source emitting at 365 nm, and using a modified TiO2 as a catalyst via the hydrothermal treatment of commercial Aeroxide P25. The experiments were performed under oxic and anoxic conditions in order to observe a possible reduction of the iron. The modified TiO2 showed a specific surface area 2.5 times greater than the original Aeroxide P25 and its isotherm and hysteresis indicated that the modified catalyst is mesoporous. The bandgap energy (Eg) of the modified TiO2 increased (3.34 eV) compared to the P25 TiO2 band gap (3.20 eV). A specific reaction rate constant of 0.1977 min−1 and an electrical oxidation efficiency of 7.77 kWh/m3 were obtained in the photocatalytic degradation. Although the TiO2 P25 yields a photocatalytic degradation 9.5% higher than that obtained one with the modified catalyst (hydrothermal), this catalyst showed better performance in terms of free cyanide release. This last aspect is a significant benefit since this can help to avoid the pollution of fresh water by reusing the treated wastewater for gold extraction. A photocatalytic degradation of the cyanocomplex of 93% was achieved when the process occurred under oxic conditions, which favored the removal. Summarizing, the hydrothermal method could be a promising treatment to obtain TiO2-based catalysts with larger specific areas. Full article
Show Figures

Figure 1

Article
A MATLAB-Based Application for Modeling and Simulation of Solar Slurry Photocatalytic Reactors for Environmental Applications
Water 2020, 12(8), 2196; https://doi.org/10.3390/w12082196 - 04 Aug 2020
Cited by 7 | Viewed by 1814
Abstract
Because of the complexity caused by photochemical reactions and radiation transport, accomplishing photoreactor modeling usually poses a barrier for young researchers or research works that focus on experimental developments, although it may be a crucial tool for reducing experimental efforts and carrying out [...] Read more.
Because of the complexity caused by photochemical reactions and radiation transport, accomplishing photoreactor modeling usually poses a barrier for young researchers or research works that focus on experimental developments, although it may be a crucial tool for reducing experimental efforts and carrying out a more comprehensive analysis of the results. This work presents PHOTOREAC, an open-access application developed in the graphical user interface of Matlab, which allows a user-friendly evaluation of the solar photoreactors operation. The app includes several solar photoreactor configurations and kinetics models as well as two variants of a radiation absorption-scattering model. Moreover, PHOTOREAC incorporates a database of 26 of experimental solar photodegradation datasets with a variety of operational conditions (model pollutants, photocatalyst concentrations, initial pollutant concentrations); additionally, users can introduce their new experimental data. The implementation of PHOTOREAC is presented using three example cases of solar photoreactor operation in which the impact of the operational parameters is explored, kinetic constants are estimated according to experimental data, and comparisons are made between the available models. Finally, the impact of the application on young researchers’ projects in photocatalysis at the University of Cartagena was investigated. PHOTOREAC is available upon request from Professor Miguel Mueses. Full article
Show Figures

Graphical abstract

Article
Towards the Removal of Antibiotics Detected in Wastewaters in the POCTEFA Territory: Occurrence and TiO2 Photocatalytic Pilot-Scale Plant Performance
Water 2020, 12(5), 1453; https://doi.org/10.3390/w12051453 - 20 May 2020
Cited by 10 | Viewed by 1468
Abstract
This research aims to assess the presence of four antibiotic compounds detected in the influent and effluent of wastewater treatment plants (WWTPs) in the POCTEFA territory (north of Spain and south of France) during the period of 2018–2019, and to relate the removal [...] Read more.
This research aims to assess the presence of four antibiotic compounds detected in the influent and effluent of wastewater treatment plants (WWTPs) in the POCTEFA territory (north of Spain and south of France) during the period of 2018–2019, and to relate the removal of antibiotic compounds with the processes used in the WWTPs. The performance of a photocatalytic TiO2/UV-VIS pilot-scale plant was then evaluated for the degradation of selected antibiotics previously detected in urban treated effluent. The main results reflect that azithromycin had the highest mass loadings (11.3 g/day per 1000 inhabitants) in the influent of one of the selected WWTPs. The results also show considerable differences in the extent of antibiotics removal in WWTPs ranging from 100% for sulfadiazine to practically 0% for trimethoprim. Finally, the photocatalytic TiO2/UV-VIS pilot-scale plant achieved the removal of the four antibiotics after 240 min of treatment from 78%–80% for trimethoprim and enrofloxacin, up to 100% for amoxicillin, sulfadiazine and azithromycin. The catalyst recovery via mechanical coagulation–flocculation–decantation was almost total. The Ti concentration in the effluent of the TiO2/UV-VIS pilot-scale plant was lower than 0.1% (w/w), and its release into the environment was subsequently minimized. Full article
Show Figures

Figure 1

Article
Evaluation of TiO2 and SnO Supported on Graphene Oxide (TiO2-GO and SnO-GO) Photocatalysts for Treatment of Hospital Wastewater
Water 2020, 12(5), 1438; https://doi.org/10.3390/w12051438 - 19 May 2020
Cited by 2 | Viewed by 1046
Abstract
The effectiveness of two photocatalysts, TiO2 and SnO, supported on graphene oxide (TiO2-GO and SnO-GO) on the removal of organic matter from hospital wastewater effluent was evaluated at laboratory scale. The results of the experimental design allow us to conclude [...] Read more.
The effectiveness of two photocatalysts, TiO2 and SnO, supported on graphene oxide (TiO2-GO and SnO-GO) on the removal of organic matter from hospital wastewater effluent was evaluated at laboratory scale. The results of the experimental design allow us to conclude that variables such as catalyst type and catalyst concentration have a significant effect on the organic matter removal efficiency of the photocatalytic process. The highest levels of removal efficiencies—for chemical oxygen demand, 85%, for phenols, 80%, and for dissolved organic carbon, 94%—were achieved using a TiO2-GO catalyst with a concentration in the wastewater of 1.5 g/L. Full article
Show Figures

Figure 1

Article
Insights into the Photocatalytic Bacterial Inactivation by Flower-Like Bi2WO6 under Solar or Visible Light, Through in Situ Monitoring and Determination of Reactive Oxygen Species (ROS)
Water 2020, 12(4), 1099; https://doi.org/10.3390/w12041099 - 12 Apr 2020
Cited by 13 | Viewed by 1637
Abstract
This study addresses the visible light-induced bacterial inactivation kinetics over a Bi2WO6 synthesized catalyst. The systematic investigation was undertaken with Bi2WO6 prepared by the complexation of Bi with acetic acid (carboxylate) leading to a flower-like morphology. The [...] Read more.
This study addresses the visible light-induced bacterial inactivation kinetics over a Bi2WO6 synthesized catalyst. The systematic investigation was undertaken with Bi2WO6 prepared by the complexation of Bi with acetic acid (carboxylate) leading to a flower-like morphology. The characterization of the as-prepared Bi2WO6 was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area (SSA), and photoluminescence (PL). Under low intensity solar light (<48 mW/cm2), complete bacterial inactivation was achieved within two hours in the presence of the flower-like Bi2WO6, while under visible light, the synthesized catalyst performed better than commercial TiO2. The in situ interfacial charge transfer and local pH changes between Bi2WO6 and bacteria were monitored during the bacterial inactivation. Furthermore, the reactive oxygen species (ROS) were identified during Escherichia coli inactivation mediated by appropriate scavengers. The ROS tests alongside the morphological characteristics allowed the proposition of the mechanism for bacterial inactivation. Finally, recycling of the catalyst confirmed the stable nature of the catalyst presented in this study. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

Review
Towards the Implementation of Circular Economy in the Wastewater Sector: Challenges and Opportunities
Water 2020, 12(5), 1431; https://doi.org/10.3390/w12051431 - 18 May 2020
Cited by 26 | Viewed by 2844
Abstract
The advancement of science has facilitated increase in the human lifespan, reflected in economic and population growth, which unfortunately leads to increased exploitation of resources. This situation entails not only depletion of resources, but also increases environmental pollution, mainly due to atmospheric emissions, [...] Read more.
The advancement of science has facilitated increase in the human lifespan, reflected in economic and population growth, which unfortunately leads to increased exploitation of resources. This situation entails not only depletion of resources, but also increases environmental pollution, mainly due to atmospheric emissions, wastewater effluents, and solid wastes. In this scenario, it is compulsory to adopt a paradigm change, as far as the consumption of resources by the population is concerned, to achieve a circular economy. The recovery and reuse of resources are key points, leading to a decrease in the consumption of raw materials, waste reduction, and improvement of energy efficiency. This is the reason why the concept of the circular economy can be applied in any industrial activity, including the wastewater treatment sector. With this in view, this review manuscript focuses on demonstrating the challenges and opportunities in applying a circular economy in the water sector. For example, reclamation and reuse of wastewater to increase water resources, by paying particular attention to the risks for human health, recovery of nutrients, or highly added-value products (e.g., metals and biomolecules among others), valorisation of sewage sludge, and/or recovery of energy. Being aware of this situation, in the European, Union 18 out of 27 countries are already reusing reclaimed wastewater at some level. Moreover, many wastewater treatment plants have reached energy self-sufficiency, producing up to 150% of their energy requirements. Unfortunately, many of the opportunities presented in this work are far from becoming a reality. Still, the first step is always to become aware of the problem and work on optimizing the solution to make it possible. Full article
Show Figures

Figure 1

Review
Use of Ultrasound as an Advanced Oxidation Process for the Degradation of Emerging Pollutants in Water
Water 2020, 12(4), 1068; https://doi.org/10.3390/w12041068 - 09 Apr 2020
Cited by 17 | Viewed by 1607
Abstract
Emerging pollutants are compounds of increased environmental importance and, as such there is interest among researchers in the evaluation of their presence, continuity and elimination in different environmental matrices. The present work reviews the available scientific data on the degradation of emerging pollutants, [...] Read more.
Emerging pollutants are compounds of increased environmental importance and, as such there is interest among researchers in the evaluation of their presence, continuity and elimination in different environmental matrices. The present work reviews the available scientific data on the degradation of emerging pollutants, mainly pharmaceuticals, through ultrasound, as an advanced oxidation process (AOP). This study analyzes the influence of several parameters, such as the nature of the pollutant, the ultrasonic frequency, the electrical power, the pH, the constituents of the matrix and the temperature of the solution on the efficiency of this AOP through researches previously reported in the literature. Additionally, it informs on the application of the referred process alone and/or in combination with other AOPs focusing on the treatment of domestic and industrial wastewaters containing emerging pollutants, mainly pharmaceuticals, as well as on the economic costs associated with and the future perspectives that make ultrasound a possible candidate to solve the problem of water pollution by these emerging pollutants.. Full article
Back to TopTop