Pharmaceutical Micropollutant Treatment with UV–LED/TiO2 Photocatalysis under Various Lighting and Matrix Conditions

Snowdon, Monika R.; Liang, Robert; Leeuwen, Jocelyn C. Van; Schneider, Olivia M.; Khan, Abrar; Fong, Lena C.M. Li Chun; Zhou, Norman Y.; Servos, Mark R.

doi:10.3390/photochem2030035

Cited by 3 publications

(2 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cenospheres were quantified by measuring the formation of 2-hydroxyterephthalic acid (HTPA) as a probe molecule since it is the product of a hydroxyl radical reaction with Terephthalic acid (TPA). Therefore, TPA degradation was used to track HTPA formation, and fluorescence (SpectraMax M3, Molecular devices, San Jose, CA, USA) was performed using previous protocols from our group [11][12][13]. This form of TPA assay allows to determine the degradation rate of the cenopheres.…”

Section: Methodsmentioning

confidence: 99%

Effects of Substituting Activated Carbon with Titanium-Dioxide-Coated Cenospheres in Conventional Aquarium Filters

Snowdon,

Liang,

Kaur

et al. 2023

Environments

Self Cite

View full text Add to dashboard Cite

We investigated the effectiveness of TiO2 cenospheres in reducing the concentrations of three common harmful compounds, ammonium, nitrate, and nitrite, in fish aquariums. These cenospheres can contribute to more sustainable and eco-friendly aquarium filtration systems while also improving the health of fish. We designed a 30-day experiment with three treatment groups based on the filter type: (1) a control group with a conventional aquarium filter, (2) a group with a TiO2 cenosphere filter, and (3) a group with a dark TiO2 cenosphere filter. The water quality was the same baseline in all groups, and each tank was monitored daily for changes in temperature, pH, ammonia, nitrate, and nitrite concentrations. We found that the TiO2 cenosphere filter was effective in reducing the concentrations of all three pollutants. By the end of the experimental period, the average concentration of nitrite in the control group was 10.7 µM, while the average concentration in the TiO2 cenosphere filter group dropped 55% to 4.7 µM from the baseline. The average concentration of nitrate was reduced by 17% and ammonia by 28% in the cenosphere-treated group. Hence, the cenospheres were effective in reducing the concentrations of all three pollutants, with the greatest reduction seen for nitrite. These findings support further investigation for incorporating TiO2 cenospheres into aquarium filtration to help reduce the environmental burden of the aquarium industry.

show abstract

Section: Methodsmentioning

confidence: 99%

Effects of Substituting Activated Carbon with Titanium-Dioxide-Coated Cenospheres in Conventional Aquarium Filters

Snowdon,

Liang,

Kaur

et al. 2023

Environments

Self Cite

View full text Add to dashboard Cite

show abstract

“…), either in situ or via the activation of added oxidants/reductants/catalysts, have been shown to be effective for elimination of CECs [ 7 , 8 , 9 ]. Among AO/RPs, heterogeneous photocatalysis, based on well-known reactions (Equations (1)–(3)) initiated by the activation of semiconducting material illuminated by sufficient energy, as follows,

have shown promising effectiveness and suitability for the removal of persistent contaminants [ 10 , 11 , 12 ]. Titanium dioxide (TiO 2 ) appears to be the most extensively studied and used photocatalyst, with still the highest potential for use in the commercial application of photocatalytic treatments [ 13 , 14 ] due to properties such as high stability, cost-effective and favorable performance [ 10 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Structural Features Promoting Photocatalytic Degradation of Contaminants of Emerging Concern: Insights into Degradation Mechanism Employing QSA/PR Modeling

et al. 2023

View full text Add to dashboard Cite

Although heterogeneous photocatalysis has shown promising results in degradation of contaminants of emerging concern (CECs), the mechanistic implications related to structural diversity of chemicals, affecting oxidative (by HO•) or reductive (by O2•−) degradation pathways are still scarce. In this study, the degradation extents and rates of selected organics in the absence and presence of common scavengers for reactive oxygen species (ROS) generated during photocatalytic treatment were determined. The obtained values were then brought into correlation as K coefficients (MHO•/MO2•−), denoting the ratio of organics degraded by two occurring mechanisms: oxidation and reduction via HO• and O2•−. The compounds possessing K >> 1 favor oxidative degradation over HO•, and vice versa for reductive degradation (i.e., if K << 1 compounds undergo reductive reactions driven by O2•−). Such empirical values were brought into correlation with structural features of CECs, represented by molecular descriptors, employing a quantitative structure activity/property relationship (QSA/PR) modeling. The functional stability and predictive power of the resulting QSA/PR model was confirmed by internal and external cross-validation. The most influential descriptors were found to be the size of the molecule and presence/absence of particular molecular fragments such as C − O and C − Cl bonds; the latter favors HO•-driven reaction, while the former the reductive pathway. The developed QSA/PR models can be considered robust predictive tools for evaluating distribution between degradation mechanisms occurring in photocatalytic treatment.

show abstract

Water Purification and Electrochemical Oxidation: Meeting Different Targets with BDD and MMO Anodes

et al. 2022

View full text Add to dashboard Cite

The complex composition of natural organic matter (NOM) can affect drinking water treatment processes, leading to perceptible and undesired taste, color and odor, and bacterial growth. Further, current treatments tackling NOM can generate carcinogenic by-products. In contrast, promising substitutes such as electrochemical methods including electrooxidation (EO) have shown safer humic acid and algae degradation, but a formal comparison between EO methods has been lacking. In this study, we compared the Boron-doped diamond (BDD) electrode electrolysis performance for Suwannee River NOM degradation using mixed-metal oxide (MMO) anodes under different pH (6.5 and 8.5) representative of the high and low ranges for acidity and alkalinity in wastewater and applied two different current densities (10 and 20 mA cm−2). BDD anodes were combined with either BDD cathodes or stainless steel (SS) cathodes. To characterize NOM, we used (a) total organic compound (TOC), (b) chemical oxygen demand (COD), (c) specific ultraviolet absorbance (SUVA), and (d) specific energy consumption. We observed that NOM degradation differed upon operative parameters on these two electrodes. BDD electrodes performed better than MMO under stronger current density and higher pH and proved to be more cost-effective. BDD-SS electrodes showed the lowest energy consumption at 4.4 × 103 kWh kg COD−1. while obtaining a TOC removal of 40.2%, COD of 75.4% and SUVA of 3.4 at higher pH and current. On the contrary, MMO produced lower TOC, COD and SUVA at the lower pH. BDD electrodes can be used in surface water as a pre-treatment in combination with some other purification technologies to remove organic contaminants.

show abstract

Pharmaceutical Micropollutant Treatment with UV–LED/TiO2 Photocatalysis under Various Lighting and Matrix Conditions

Cited by 3 publications

References 40 publications

Effects of Substituting Activated Carbon with Titanium-Dioxide-Coated Cenospheres in Conventional Aquarium Filters

Effects of Substituting Activated Carbon with Titanium-Dioxide-Coated Cenospheres in Conventional Aquarium Filters

Structural Features Promoting Photocatalytic Degradation of Contaminants of Emerging Concern: Insights into Degradation Mechanism Employing QSA/PR Modeling

Water Purification and Electrochemical Oxidation: Meeting Different Targets with BDD and MMO Anodes

Contact Info

Product

Resources

About