Removal of Aqueous Emerging Contaminants through Photodegradation and (Photo)catalysis

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

Deadline for manuscript submissions: closed (16 November 2023) | Viewed by 11420

Special Issue Editors


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Guest Editor
School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China
Interests: bioelectrical chemistry; environmental materials

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Guest Editor
School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, China
Interests: wastewater treatment; recalcitrant organic contaminants; catalytic oxidation; ecotoxicity; biodegradation

Special Issue Information

Dear Colleagues,

Quality of water is an importance attribute in the water industry. Contaminants with known or unknown health effects, once produced, will find their ways to enter aquatic environments. Their occurrence, fates and behaviors in water environments, and potential impacts have been receiving considerable attention from researchers, practitioners and regulators worldwide. Nonetheless, sustainable control strategies for contaminants in water and wastewater still remain a challenge in today's water industry. Nowadays, most of the treatment technologies in water and wastewater field require considerable energy and chemicals to remove the emerging contaminants. Greener approaches such as photolysis or (photo)catalysis, which make use of various light sources and catalysts for decomposition or degradation of emerging contaminants (including inorganic, organic and microbial contaminants) are gaining more and more attentions.

As contamination issues in water have become increasingly important due to rapid population growth, industrialization, urbanization, climate change, etc., it would be desirable to have a Special Issue to look into topics such as sustainable treatment technologies for emerging contaminants control and their process modelling. Therefore, we seek scientific findings and results in the abovementioned areas, which can contribute to new knowledge for sustainable control strategies for emerging contaminants in water and wastewater.

We would like to invite authors to submit original research and review articles focusing on emerging contaminants control in water and wastewater via photodegradation and (photo)catalysis processes.

The sub-topics to be covered within the issue should be provided as follows:

  • Photodegradation process for emerging contaminant removal;
  • (Photo)catalytic process for emerging contaminant removal;
  • Fate and behaviours of emerging contaminants in treatment processes;
  • Data analysis and modelling;
  • Toxicity assessment of treated water and wastewater;
  • Control and removal of emerging contaminants by hybrid processes.

Prof. Dr. Jiangyong Hu
Prof. Dr. Say Leong Ong
Prof. Dr. Guangli Liu
Prof. Dr. Yongjun Zhang
Guest Editors

Manuscript Submission Information

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Keywords

  • emerging contaminant removal
  • photodegradation
  • (photo)catalysis
  • modelling
  • water and wastewater treatment

Published Papers (5 papers)

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Research

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15 pages, 4839 KiB  
Article
Surface Modification of TiO2/g-C3N4 Electrode with N, P Codoped CQDs for Photoelectrocatalytic Degradation of 1,4-Dioxane
by Yuehan Su, Yongbei Ye, Songwei Lin, Yaobin Lu, Haiping Luo and Guangli Liu
Water 2023, 15(15), 2837; https://doi.org/10.3390/w15152837 - 6 Aug 2023
Cited by 1 | Viewed by 1071
Abstract
The aim of this study was to synthesize N, P codoped CQDs modifying TiO2/g-C3N4 nanorod array (i.e., N, P-CQD/TCN NA) photoanodes for the degradation of 1,4-dioxane (1,4-D) and to explore the possibility of the photoelectrocatalytic (PEC) process in [...] Read more.
The aim of this study was to synthesize N, P codoped CQDs modifying TiO2/g-C3N4 nanorod array (i.e., N, P-CQD/TCN NA) photoanodes for the degradation of 1,4-dioxane (1,4-D) and to explore the possibility of the photoelectrocatalytic (PEC) process in wastewater treatment. With the characterization of N, P-CQD/TCN NA anodes, 1,4-D degradation and pesticide wastewater was tested in the PEC cell, respectively. Under a bias voltage of 1.2 V and visible light, the current density of the N, P-CQD/TCN NAs was much higher than that of the CQD/TCN NAs (0.15 vs. 0.11 mA/cm2). The removal of 1,4-D reached 97% in the PEC cell within 6 h. The high performance of the N, P-CQD/TCN NA anodes could be attributed to the efficient charge separation, narrowed energy gap, and high upconverted PL properties. The C4 and C6 positions of 1,4-D were the preferential sites for the nucleophilic attack to form intermediates. The COD removal in the pesticide wastewater was kept stable at ~80% in a five-cycle operation using the PEC cell with the N, P-CQD/TCN NA photoelectric anodes. The results from this study should provide a promising way to develop novel photoelectric catalysts and to expand PEC application in wastewater treatment. Full article
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28 pages, 4876 KiB  
Article
Degradation of Carbamazepine by HF-Free-Synthesized MIL-101(Cr)@Anatase TiO2 Composite under UV-A Irradiation: Degradation Mechanism, Wastewater Matrix Effect, and Degradation Pathway
by J. W. Goh, Y. Xiong, W. Wu, Z. Huang, S. L. Ong and J. Y. Hu
Water 2022, 14(23), 3964; https://doi.org/10.3390/w14233964 - 5 Dec 2022
Cited by 2 | Viewed by 2392
Abstract
TiO2 has been hampered by drawbacks such as rapid photoelectron and hole recombination and a wide energy band gap of 3.2 eV. In this study, MIL-101(Cr)@TiO2 was synthesised without any mineraliser (HF) as part of material modification approach to overcome those [...] Read more.
TiO2 has been hampered by drawbacks such as rapid photoelectron and hole recombination and a wide energy band gap of 3.2 eV. In this study, MIL-101(Cr)@TiO2 was synthesised without any mineraliser (HF) as part of material modification approach to overcome those pitfalls. The composite was well characterized by XRD, FT-IR, TEM, XPS, BET, TGA, and Raman spectroscopy. Under optimal synthesis conditions, the 9.17% MIL-101(Cr)@TiO2 composite exhibited 99.9% CBZ degradation after 60 min under UV-A irradiation. This can be attributed to the delayed recombination of photo-generated h+ and e and a reduced band gap energy of 2.9 eV. A Type II heterojunction structure was proposed for the composite using the Mulligan function of electronegativity with the calculated Ecb and Evb. Besides, trapping experiments and ESR spectroscopy confirmed O2•− as the main ROS for CBZ degradation. The effects of the operating parameters such as pH, UV intensity, composite dosage, and initial pollutant concentration were also evaluated. The scavenging effects of inorganic and organic constituents of pharmaceutical wastewater on the process were also evaluated, with HCO3, CO32−, and THF having more significant inhibition on the overall CBZ degradation. The degradation pathways of CBZ were also proposed based on detected intermediates with the aid of LC/MS/MS. The composite illustrated reusability and stability without considerable loss in the degradation performance after repeated runs. This work builds on the development of more effective photocatalysts and provides a glimpse into applications for similar MOF heterojunction photocatalysts. Full article
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12 pages, 4071 KiB  
Article
Controlling Biofilm Growth and Its Antibiotic Resistance in Drinking Water by Combined UV and Chlorination Processes
by Yiwei Chen, Yizhen Li, Shaolun Yang, Tsung Yen Chiang, Xiaoying Zhu and Jiangyong Hu
Water 2022, 14(22), 3643; https://doi.org/10.3390/w14223643 - 11 Nov 2022
Cited by 1 | Viewed by 2581
Abstract
Combined use of light-emitting diodes (LED) ultraviolet (UV) and chlorination provides alternative disinfection in drinking water, which could affect the biofilm formed subsequently. Two sequential integrations (UV-Cl and Cl-UV) and one simultaneous combination (UV/Cl) were adopted to investigate their impacts on biofilm formation. [...] Read more.
Combined use of light-emitting diodes (LED) ultraviolet (UV) and chlorination provides alternative disinfection in drinking water, which could affect the biofilm formed subsequently. Two sequential integrations (UV-Cl and Cl-UV) and one simultaneous combination (UV/Cl) were adopted to investigate their impacts on biofilm formation. Natural organic matter after combined processes was more accessible for microbes. This might explain the promoted growth of culturable biofilm bacteria—biofilm bacteria stabilized at 104 CFU/mL without disinfection while increasing continuously to 105 CFU/mL in 106 days after combined processes. Contrarily, the viable biofilm bacteria were efficiently suppressed by combined processes, with the least bacteria observed in UV/Cl. The culturable ciprofloxacin-resistant bacteria in biofilm was suppressed by combined processes, with the survival reduced from 49.9% in the control to 27.7%, 16.0% and 10.8% in UV-Cl, Cl-UV and UV/Cl, respectively. The survival of sulfamethoxazole/trimethoprim-resistant bacteria was lower in UV/Cl (16.8%) than others (43.6–55.0%), consistent with the little sul1 and sul2 detected in UV/Cl. Although combined processes reduced most detected antibiotic resistance genes (i.e., blaTEM-1, tetA, sul1 and sul2), UV-Cl showed the potential to enrich tetA and sul2 in biofilm. Overall, UV/Cl outperformed the sequential combinations in the control of viable bacteria and the antibiotic resistance in the subsequently formed biofilm. Full article
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Review

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20 pages, 1562 KiB  
Review
Assessing the Sustainability of Photodegradation and Photocatalysis for Wastewater Reuse in an Agricultural Resilience Context
by Tiziana Crovella and Annarita Paiano
Water 2023, 15(15), 2758; https://doi.org/10.3390/w15152758 - 30 Jul 2023
Cited by 4 | Viewed by 1813
Abstract
The growths in worldwide population—of up to 8.5 billion people by 2030—and agriculture have put great pressure on water resources, above all in arid and drought-prone areas. Nowadays, water scarcity, drought and pollution of wastewater are considered major issues of concern. For this [...] Read more.
The growths in worldwide population—of up to 8.5 billion people by 2030—and agriculture have put great pressure on water resources, above all in arid and drought-prone areas. Nowadays, water scarcity, drought and pollution of wastewater are considered major issues of concern. For this reason, the authors provided an overview of two methods of wastewater purification and removing pollutants for use in crop irrigation in a sustainable manner. The novelty lies in the reuse of recovered wastewater, purified through photodegradation and photocatalysis technologies using solar energy. The knowledge of the environmental impacts associated with the use of recycled water with these photo-processes to irrigate crops under field conditions is still scarce. In the future, this issue will be important. In particular, photodegradation and photocatalysis achieve a sustainable reduction in contaminants contained in wastewater of between 35% and 100%. The use of bismuth vanadate supports the complete removal of pollutants, and the implementation of catalytic membranes makes these processes more circular. This research was performed under the “Progetto GRINS “Growing Resilient, Inclusive and Sustainable” with the aim of “Building a dataset for the circular economy of the main Italian production systems”. Full article
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26 pages, 6456 KiB  
Review
Spinel-Ferrite-Decorated Graphene-Based Nanocomposites for Enhanced Photocatalytic Detoxification of Organic Dyes in Aqueous Medium: A Review
by Subhasish Mishra, Rashmi Acharya and Kulamani Parida
Water 2023, 15(1), 81; https://doi.org/10.3390/w15010081 - 26 Dec 2022
Cited by 32 | Viewed by 2659
Abstract
The contamination of organic dye molecules in aquatic environments caused by the effluents released from vast industrial establishments has been a matter of serious concern in recent years, owing to their strong non-biodegradable nature and acute toxicity. Semiconductor-mediated visible-light-driven photocatalytic-dye detoxification is considered [...] Read more.
The contamination of organic dye molecules in aquatic environments caused by the effluents released from vast industrial establishments has been a matter of serious concern in recent years, owing to their strong non-biodegradable nature and acute toxicity. Semiconductor-mediated visible-light-driven photocatalytic-dye detoxification is considered as a sustainable technique because it abundantly utilizes the available solar energy and releases environmentally friendly chemicals such as H2O as byproducts. Adequate textural and microstructural properties, an extended visible-light response, pronounced isolation and transfer of photoinduced charge carriers, and facile magnetic-separation characteristics make spinel-ferrite-decorated graphene or its analogues’ (GO/rGO) nanocomposites (MFGNs) a versatile photocatalytic system for the efficacious detoxification of dyes. Therefore, this review article emphasizes their exceptional photodegradation performance in terms of systematic studies of the above-mentioned features, after a brief description of the synthesis protocols. The mechanism of the photodetoxification of dyes over MFGNs is precisely demonstrated in three different sections based on their redox abilities. The kinetics of the MFGN-driven photodecomposition of dyes are then highlighted. We discuss the role of different parameters such as pH, temperature, catalyst dose, and dye concentration in augmented photocatalytic-dye-degradation reactions. Finally, the emerging challenges that act as hurdles in achieving superior photocatalytic-dye-detoxification performance are addressed, along with the conclusion. We then propose some possible future research directions in order to overcome these challenges, for impressively accomplishing the photodegradation of organic dyes. Full article
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