State-of-the-Art Photochemical Technology for Water and Wastewater Treatment

Topic Information

Dear Colleagues,

Recent studies have been devoted to the use of advanced oxidation processes (AOPs) for the destruction of organic materials from water and wastewater, mainly because AOPs can entirely eradicate organics. Depending on the applications, different AOPs have been studied. Among AOPs, photocatalysis is a promising process of eradicating almost all types of organics in wastewater. Despite the advantages of TiO₂, there are two major limitations in its photocatalytic activity: its activation in the ultraviolet range, and its high rate of electron-hole recombination, leading to its low efficiency. Therefore, the photocatalytic efficiency depends on how well a photocatalyst can prevent electron-hole pair recombination. There have been many studies on photocatalysis, including doping metals and non-metals, as well as mixing different photocatalysts. Other AOPs, such as UV/H₂O₂, UV/Ozone, Fenton, Fenton-like, photoFenton, photoelectrochemical processes among others, have been studied for different applications, including the destruction of organic pollutants and disinfection of pathogens. The focus of this Topic is on the latest developments in all AOPs, including photochemical reaction engineering, photoreactor design with high mass transfer rate, photocatalyst development, or combining different AOPs with other processes to enhance organic degradation in water and wastewater. This Topic strives to provide an overview on state-of-the-art photochemical technology for water and wastewater treatment. All papers should report on trends and advances in the fields of photochemical technologies for water and wastewater treatment.

Prof. Dr. Mehrab Mehrvar
Prof. Dr. Marta Gmurek
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Catalysts catalysts	3.8	6.8	2011	13.9 Days	CHF 2200
ChemEngineering ChemEngineering	2.8	4.0	2017	32.8 Days	CHF 1600
International Journal of Environmental Research and Public Health ijerph	-	7.3	2004	25.8 Days	CHF 2500
Molecules molecules	4.2	7.4	1996	15.1 Days	CHF 2700
Water water	3.0	5.8	2009	17.5 Days	CHF 2600

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Published Papers (9 papers)

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17 pages, 2008 KiB  

Open AccessArticle

Bacterial Communities in Effluents Rich in Phenol and Their Potential in Bioremediation: Kinetic Modeling

by Miriam M. Morones-Esquivel, Cynthia M. Núñez-Núñez, José L. Hernández-Mendoza and José B. Proal-Nájera

Int. J. Environ. Res. Public Health 2022, 19(21), 14222; https://doi.org/10.3390/ijerph192114222 - 31 Oct 2022

Cited by 5 | Viewed by 1902

Abstract

Phenol is used in the manufacturing process of phenolic resins from which residues remain that must be sent for confinement. For that reason, in this study, the wastewater of a resin factory was analyzed to isolate the bacteria present, identify them by molecular [...] Read more.

Phenol is used in the manufacturing process of phenolic resins from which residues remain that must be sent for confinement. For that reason, in this study, the wastewater of a resin factory was analyzed to isolate the bacteria present, identify them by molecular methods and finally evaluate their impact on bioremediation treatment. A total of 15 bacteria were isolated, of these, eight belong to the genus Bacillus spp. All bacteria were individually multiplied and inoculated in clusters in 15 L reactors which were carefully monitored for pH, electrical conductivity, chemical oxygen demand and temperature. The acquired data were analyzed using ANOVA with repeated measurements. The first test revealed that native bacterial communities reduce the phenol content by up to 20% and COD by 49%, which is significant with respect to the reactor not being inoculated with bacteria. Furthermore, when a mathematical model was applied to the reactors, it was shown that the bacteria require an adaptation time of approximately 100 h. A second test where the inoculation was interspersed with the addition of lime as a flocculant showed that, even though the reduction in phenol and COD was lower than in the previous test, the difference between treatments and control is statistically significant (α ≤ 0.05). Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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13 pages, 3494 KiB  

Open AccessArticle

Facile Synthesis of ZnSe/Co₃O₄ Heterostructure Nanocomposites for the Photocatalytic Degradation of Congo Red Dye

by Adeel Zia, Abdul Basit Naveed, Aftab Javaid, Muhammad Fahad Ehsan and Azhar Mahmood

Catalysts 2022, 12(10), 1184; https://doi.org/10.3390/catal12101184 - 7 Oct 2022

Cited by 11 | Viewed by 2815

Abstract

In the present paper, simple hydrothermal and solid-state methods are reported for the synthesis of metal chalcogenide (ZnSe), metal oxide (Co₃O₄) and their nano-heterostructure (ZnSe/Co₃O₄ 3:1, 1:1 and 1:3 ratios by weight), while their photocatalytic efficiencies [...] Read more.

In the present paper, simple hydrothermal and solid-state methods are reported for the synthesis of metal chalcogenide (ZnSe), metal oxide (Co₃O₄) and their nano-heterostructure (ZnSe/Co₃O₄ 3:1, 1:1 and 1:3 ratios by weight), while their photocatalytic efficiencies are also investigated. The X-ray diffraction results corroborate the good crystallinity and purity of all synthesized products, i.e., ZnSe, Co₃O₄ and their nanocomposites. The scanning electron micro-images of ZnSe show a mixed morphology of nanoparticles (≈16 nm), including spherical and distorted cubes, while Co₃O₄ has a worm-like morphology (≈20 × 50 nm). The EDX results show that all the elements are present in accordance with their anticipated amounts in the products. The UV/visible absorption spectrum of ZnSe depicts a sharp absorption at around 480 nm, while Co₃O₄ demonstrates two prominent peaks, 510 nm and 684 nm. The prepared samples were employed for the photocatalytic degradation of Congo red dye and the nano-heterostructure (ZnSe/Co₃O₄ 3:1) shows an exceptional photocatalytic degradation efficiency of 96%. This enhanced photocatalytic activity was due to the synergic effect of ZnSe and Co₃O₄ that reduced the electron/hole recombination and caused suitable bandgap alignment. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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15 pages, 4461 KiB  

Open AccessArticle

TPPS₄—Sensitized Photooxidation of Micropollutants—Singlet Molecular Oxygen Kinetic Study

by Marta Gmurek

Molecules 2022, 27(16), 5260; https://doi.org/10.3390/molecules27165260 - 17 Aug 2022

Cited by 3 | Viewed by 1921

Abstract

Visible light-sensitized oxidation of micropollutants (MPs) in the presence of meso-tetrakis(4-sulfonatophenyl)porphyrin photosensitizers was studied. In order to explore the role of type I (ROS generation) or type II (singlet oxygen) photooxidation, radical scavengers were used to obtain insight into the mechanism of photodegradation. [...] Read more.

Visible light-sensitized oxidation of micropollutants (MPs) in the presence of meso-tetrakis(4-sulfonatophenyl)porphyrin photosensitizers was studied. In order to explore the role of type I (ROS generation) or type II (singlet oxygen) photooxidation, radical scavengers were used to obtain insight into the mechanism of photodegradation. It was revealed that singlet oxygen is the main ROS taking part in TPPS₄- sensitized photooxidation of micropollutants. The interaction of MPs with ¹O₂ in deuterium oxide (D₂O) was investigated by measuring the phosphorescence lifetime of ¹O₂. The rate constant (kq) for the total (physical and chemical) quenching of ¹O₂ by MPs was determined in a D₂O buffer (pD 7, 9 and 10.8). The rate constants of singlet oxygen quenching and reaction with MPs were determined, and the rate constant of excited TPPS₄ quenching by MPs was also estimated. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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17 pages, 2913 KiB  

Open AccessArticle

Effect of an Electromagnetic Field on Anaerobic Digestion: Comparing an Electromagnetic System (ES), a Microbial Electrolysis System (MEC), and a Control with No External Force

by Nhlanganiso Ivan Madondo, Emmanuel Kweinor Tetteh, Sudesh Rathilal and Babatunde Femi Bakare

Molecules 2022, 27(11), 3372; https://doi.org/10.3390/molecules27113372 - 24 May 2022

Cited by 17 | Viewed by 3106

Abstract

This study examined the application of an electromagnetic field to anaerobic digestion by using an electromagnetic system (ES), a microbial electrolysis cell (MEC), and a control with no external force. The experimental work was performed by carrying out biochemical methane potential (BMP) tests [...] Read more.

This study examined the application of an electromagnetic field to anaerobic digestion by using an electromagnetic system (ES), a microbial electrolysis cell (MEC), and a control with no external force. The experimental work was performed by carrying out biochemical methane potential (BMP) tests using 1 L biodigesters. The bioelectrochemical digesters were supplied with 0.4 V for 30 days at 40 °C. The electromagnetic field of the ES was generated by coiling copper wire to form a solenoid in the BMP system, whereas the MEC consisted of zinc and copper electrodes inside the BMP system. The best performing system was the MEC, with a yield of 292.6 mL CH₄/g chemical oxygen demand removed (COD_removed), methane content of 86%, a maximum current density of 23.3 mA/m², a coulombic efficiency of 110.4%, and an electrical conductivity of 180 µS/cm. Above 75% removal of total suspended solids (TSS), total organic carbon (TOC), phosphate, and ammonia nitrogen (NH₃-N) was also recorded. However, a longer exposure (>8 days) to higher magnetic intensity (6.24 mT) on the ES reduced its overall performance. In terms of energy, the MEC produced the greatest annual energy profit (327.0 ZAR/kWh or 23.36 USD/kWh). The application of an electromagnetic field in anaerobic digestion, especially a MEC, has the potential to maximize the methane production and the degradability of the wastewater organic content. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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11 pages, 2458 KiB  

Open AccessArticle

Polyacrylonitrile Derived Robust and Flexible Poly(ionic liquid)s Nanofiber Membrane as Catalyst Supporter

by Yue Gao, Qing-Bo Meng, Bao-Xin Wang, Yu Zhang, Hui Mao, Da-Wei Fang and Xi-Ming Song

Catalysts 2022, 12(3), 266; https://doi.org/10.3390/catal12030266 - 26 Feb 2022

Cited by 9 | Viewed by 2739

Abstract

Poly(ionic liquid)s nanofiber (PIL NF) membrane was derived from polyacrylonitrile by converting its cyano groups to imidazoline moieties via cyclization with ethylenediamine, followed by quaternization with 1-bromobutane. The novel PIL NF is further decorated with photocatalyst phosphotungstic acid PW12 via anion exchanging to [...] Read more.

Poly(ionic liquid)s nanofiber (PIL NF) membrane was derived from polyacrylonitrile by converting its cyano groups to imidazoline moieties via cyclization with ethylenediamine, followed by quaternization with 1-bromobutane. The novel PIL NF is further decorated with photocatalyst phosphotungstic acid PW12 via anion exchanging to give PW-PIL. The degradation rate of the novel supported photocatalyst towards methyl orange irradiated under visible light was found to be 98%. In addition, the nanofiber membrane morphology is beneficial for easy recycling, and 98% of original degradation rate was maintained after 5 cycles of photocatalysis degradation. This robust, efficient, and recyclable material offers a new approach for serving as catalyst supporter. The photocatalyst PW-PIL is reported for the first time. The inexpensive functional membrane is used to exploit the sun as a cheap and clean source of light. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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13 pages, 5700 KiB  

Open AccessArticle

Research on Micro-Quantitative Detection Technology of Simulated Waterbody COD Based on the Ozone Chemiluminescence Method

by Peng Li, Yizhuo Wang and Bo Xu

Water 2022, 14(3), 328; https://doi.org/10.3390/w14030328 - 23 Jan 2022

Cited by 5 | Viewed by 3714

Abstract

Chemical oxygen demand (COD), reflecting the degree of waterbody contaminated by reduction substances, is an important parameter for water quality monitoring. The existing measurement method of waterbody COD takes time and is a complex system, which cannot meet the real-time monitoring requirements of [...] Read more.

Chemical oxygen demand (COD), reflecting the degree of waterbody contaminated by reduction substances, is an important parameter for water quality monitoring. The existing measurement method of waterbody COD takes time and is a complex system, which cannot meet the real-time monitoring requirements of river pollution indicators. We developed the vortex t-structure microfluidic detection chip with the help of microfluidic technology and designed the COD detection system with a high integration degree based on the principle of ozone chemiluminescence, and we have also carried out research on a waterbody COD quantitative detection test. The test results show that the detection chip can generate quantitative and controllable ozone-based bubbles; it also shows the advantages of a simple system and short test time without environmental pollution, which provides some technical support for the online real-time monitoring of river water quality. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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16 pages, 4884 KiB  

Open AccessArticle

Study of Semi-Dry High Target Solidification/Stabilization of Harmful Impurities in Phosphogypsum by Modification

by Fenghui Wu, Can Yang, Guangfei Qu, Liangliang Liu, Bangjin Chen, Shan Liu, Junyan Li, Yuanchuan Ren and Yuyi Yang

Molecules 2022, 27(2), 462; https://doi.org/10.3390/molecules27020462 - 11 Jan 2022

Cited by 14 | Viewed by 2247

Abstract

Phosphogypsum (PG) treatment is one of the research hotspots in the field of environmental protection. Many researchers both at home and abroad have devoted themselves to studies on harmless resource treatment of PG, but the treatment technology is unable to meet the demand [...] Read more.

Phosphogypsum (PG) treatment is one of the research hotspots in the field of environmental protection. Many researchers both at home and abroad have devoted themselves to studies on harmless resource treatment of PG, but the treatment technology is unable to meet the demand of PG consumption due to the huge production and storage demands. In order to solve the problem of PG pollution, this study explored the different solidified effects of various modification formulations on the hazardous components in PG, using industrial solid waste calcium carbide slag (CCS) as an alkaline regulator; Portland cement (PC), polyaluminum chloride (PAC) and CaCl₂ as the main raw materials of the solidification and stabilization formula and the water content in PG as the reaction medium. The results showed that CCS (0.5%), PC (0.4%) and PAC (0.3%) had a more significant solidified effect on phosphorus (P) and fluoride (F). PAC was added in two steps and reacted under normal temperature and pressure, and its leaching toxicity meets the requirements of relevant standards, which laid an excellent foundation for PG-based ecological restoration materials and filling materials, with low economic cost, simple process and strong feasibility. This will provide great convenience for the later mining and metallurgy. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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18 pages, 1492 KiB  

Open AccessArticle

Effect of the Aeration Strategy on NOB Suppression in Activated Sludge and Biofilm in a Hybrid Reactor with Nitrification/Denitrification

by Olga Zajac, Monika Zubrowska-Sudol, Slawomir Ciesielski and Martyna Godzieba

Water 2022, 14(1), 72; https://doi.org/10.3390/w14010072 - 1 Jan 2022

Cited by 8 | Viewed by 3556

Abstract

The purpose of the study was to analyse the impact of aeration strategies defined by the changes in the duration of aerated sub-phases, the ratio between non-aerated and aerated sub-phase times (R), and dissolved oxygen concentrations (DO) on the suppression of nitrite-oxidizing bacteria [...] Read more.

The purpose of the study was to analyse the impact of aeration strategies defined by the changes in the duration of aerated sub-phases, the ratio between non-aerated and aerated sub-phase times (R), and dissolved oxygen concentrations (DO) on the suppression of nitrite-oxidizing bacteria (NOB) in activated sludge and biofilm developing in a hybrid reactor with nitrification/denitrification. The primary factor causing NOB suppression both in biofilm and in activated sludge was an increase in the R-value (from 0 to 1/4 and from 1/4 to 1/3). After reducing the DO from 3 to 2 mg O₂/L, there were no changes in the frequency of NOB occurrence, and no reduction in the nitrite oxidation rate was recorded. The abundance of Comammox bacteria was considerably affected by the change from continuous to intermittent aeration. Activated sludge showed a substantial increase in the quantity of clade A and B, whereas the quantity considerably decreased in biofilm. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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19 pages, 7282 KiB  

Open AccessFeature PaperArticle

Treatment of Actual Winery Wastewater by Fenton-like Process: Optimization to Improve Organic Removal, Reduce Inorganic Sludge Production and Enhance Co-Treatment at Municipal Wastewater Treatment Facilities

by Melody Blythe Johnson and Mehrab Mehrvar

Water 2022, 14(1), 39; https://doi.org/10.3390/w14010039 - 24 Dec 2021

Cited by 12 | Viewed by 3825

Abstract

Despite many wineries being equipped with onsite wastewater treatment, winery wastewater (WWW) co-treatment at municipal wastewater treatment plants (WWTPs) remains a common practice in wine-making regions. The complex and highly variable nature of WWW can result in negative impacts on WWTP operations, highlighting [...] Read more.

Despite many wineries being equipped with onsite wastewater treatment, winery wastewater (WWW) co-treatment at municipal wastewater treatment plants (WWTPs) remains a common practice in wine-making regions. The complex and highly variable nature of WWW can result in negative impacts on WWTP operations, highlighting a need for improved co-treatment methods. In this paper, the feasibility of using the Fenton-like process to pre-treat WWW to enhance co-treatment at municipal WWTPs is assessed. First-stage pre-treatment of the WWW, in the form of dilution and settling or aerobic biological treatment, is used prior to the Fenton-like process. A three-factor BBD experimental design is used to identify optimal reaction time and initial H₂O₂ and Fe³⁺ concentrations. Chemical oxygen demand (COD) and total organic carbon (TOC) removal rates are not able to accurately reflect the extent of reaction. Additional trials identified solubilization of particulate COD and TOC, as well as samples handling requirements prior to analysis, as factors affecting the apparent COD and TOC removal rates. Inert suspended solids (ISS) generated during the sample handling process are found to be the response variable best suited to quantifying the extent of the Fenton-like reaction. Maximum ISS generation is observed at initial H₂O₂ and Fe³⁺ concentrations of 4000 mg/L and 325 mg/L, however, results suggest that optimal concentrations exceed these values. The impact of adding pre-treated WWW, with and without Fenton-like treatment, to municipal WWTPs’ primary clarifiers and aerobic bioreactors is also assessed via bench-scale trials. Challenges associated with co-treating WWW are found to remain despite the pre-treatment alternatives investigated, including negative impacts on simulated primary and secondary effluent quality. The Fenton-like AOP provides limited opportunity to optimize or enhance co-treatment at municipal WWTPs. Full article

(This article belongs to the Topic State-of-the-Art Photochemical Technology for Water and Wastewater Treatment)

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