A novel photodegradation approach for the efficient removal of natural organic matter (NOM) from water

Ndlangamandla, Nqobile G.; Kuvarega, Alex T.; Msagati, Titus A.M.; Mamba, Bhekie B.; Nkambule, Thabo T.I.

doi:10.1016/j.pce.2018.05.011

Cited by 20 publications

(8 citation statements)

References 32 publications

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“…This result may be related to the photosensitization effect of NOM. As indicated by prior studies, NOM can also have two contrasting effects on TiO 2 photocatalysis [36][37][38]. It can either inhibit the photodegradation by scavenging the photoinduced holes, attenuate the light, compete for active sites, deactivate the photocatalyst surface [39], or act as precursor for reactive radical species in water matrices [40].…”

Section: Effect Of Water Matricesmentioning

confidence: 96%

Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

et al. 2021

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In this study, we evaluated the effectiveness of UV-LED-irradiated TiO2 in removing 24 commonly detected PPCPs in two water matrices (municipal wastewater effluent and Suwannee River NOM–synthetic water) and compared their performance with that of ultrapure water. Relatively fast removal kinetics were observed for 29% and 12% of the PPCPs in ultrapure water and synthetic surface water, respectively (kapp of 1–2 min−1). However, they all remained recalcitrant to photocatalysis when using wastewater effluent as the background matrix (kapp < 0.1 min−1). We also observed that the pH-corrected octanol/water partition coefficient (log Dow) correlated well with PPCP degradation rate constants in ultrapure water, whereas molecular weight was strongly associated with the rate constants in both synthetic surface water and wastewater. The electrical energy per order (EEO) values calculated at the end of the experiments suggest that UV-LED/P25 can be an energy-efficient method for water treatment applications (2.96, 4.77, and 16.36 kW h m−3 in ultrapure water, synthetic surface water, and wastewater effluents, respectively). Although TiO2 photocatalysis is a promising approach in removing PPCPs, our results indicate that additional challenges need to be overcome for PPCPs in more complex water matrices, including an assessment of photocatalytic removal under different background water matrices.

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Section: Effect Of Water Matricesmentioning

confidence: 96%

Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

et al. 2021

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“…Other chemical modifications include the addition of non-metals (such as C, N, S, or F) which have also been shown to form new impurity levels close to the valence or conduction band of TiO 2 , thereby lowering the optical gap and shifting the absorption edge to the visible light region [113]. Nkambules [86] 2012 work focuses on N-doped TiO 2 , a growing area of photocatalysis which has been shown to increase visible light photocatalytic activity when coupled with co-dopant metals by reducing the band gap of TiO 2 and shifted the absorption into the visible light region [89,114]. The Pd-modified N-doped TiO 2 catalyst synthesised by Nkambule et al in 2012 showed a particularly successful shift in titania's visible light absorption with an over 70% removal in hydrophobic NOM fractions using a solar simulator.…”

Section: Visible Light Driven Modified Tio 2 Catalystsmentioning

confidence: 99%

“…Work done by Zhang et al [90] showed that creating titania nanotubes can not only improve upon P25-TiO 2 s ability to photocatalytically degrade NOM, most likely due to increased surface area, but also significantly reduces the amount of membrane fouling caused by catalyst separation. Another approach to reducing the need for catalyst separation when photocatalytically degrading NOM is producing hybrid materials by combining TiO 2 with carbon materials such as multiwalled carbon nanotubes [89] and activated carbons [97]. A particularly successful example of this is the work done by Xue et al where a TiO 2 nanoparticle/granular activated carbon composite (GAC) was prepared by a sol-dippinggel process.…”

Section: Immobilized Catalystsmentioning

confidence: 99%

“…When focussing on heterogeneous photocatalysis, most research tends to either focus on the optimisation of the photocatalytic activity of TiO 2 or to synthesise novel photocatalysts able to compete with TiO 2 . The improved degradation capabilities of TiO 2 are commonly explored via structural modifications (nanocrystals, [155] nanoparticles, [116] nanotubes, [90] nanowires, [117] and nanofilms [118]) and/or combination with other catalysts (ZnO) [156] or materials (polymers, [157] multiwalled carbon nanotubes, [89] and activated carbons [97]). Alternatively, novel photocatalysts are regularly chosen based on their superior photocatalytic activity under near visible or solar light when compared to a TiO 2 standard.…”

Section: Conclusion and Considerations For Future Researchmentioning

confidence: 99%

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Photocatalytic Oxidation of Natural Organic Matter in Water

Gowland

Robertson

Chatzisymeon

2021

Water

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Increased concentrations of natural organic matter (NOM), a complex mixture of organic substances found in most surface waters, have recently emerged as a substantial environmental issue. NOM has a significant variety of molecular and chemical properties, which in combination with its varying concentrations both geographically and seasonally, introduce the opportunity for an array of interactions with the environment. Due to an observable increase in amounts of NOM in water treatment supply sources, an improved effort to remove naturally-occurring organics from drinking water supplies, as well as from municipal wastewater effluents, is required to continue the development of highly efficient and versatile water treatment technologies. Photocatalysis has received increasing interest from around the world, especially during the last decade, as several investigated processes have been regularly reported to be amongst the best performing water treatment technologies to remove NOM from drinking water supplies and mitigate the formation of disinfection by products. Consequently, this overview highlights recent research and developments on the application of photocatalysis to degrade NOM by means of TiO2-based heterogeneous and homogeneous photocatalysts. Analytical techniques to quantify NOM in water and hybrid photocatalytic processes are also reviewed and discussed.

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“…Spread of these diseases via drinking water can be prevented by disinfection [2]. The most commonly used and cheapest disinfectant is chlorine, which deactivates microorganisms in drinking water treatment plants [3]. This process has serious drawbacks due to generation of toxic and carcinogenic products such as trihalomethanes and haloacetic acids [4,5].…”

Section: Introductionmentioning

confidence: 99%

LLDPE Composites with Nanosized Copper and Copper Oxides for Water Disinfection

et al. 2020

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Consumption of contaminated water may lead to dangerous and even fatal water-borne diseases. Disinfection of drinking water is the most effective solution for this problem. The most common water treatment methods are based on the use of toxic disinfectants. Composites of polymers with nanosized metals and their oxides may become a good alternative to the existing methods. Expanding the scope of our previous publication, copper, cuprous, and copper oxide nanoparticles were immobilized onto linear low-density polyethylene by a simple thermal adhesion method. The antibacterial efficiency of the immobilized nanoparticles was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in batch experiments and for the first time the efficiency of these composites is reported for continuous flow regime. Immobilized copper and cuprous oxide nanoparticles demonstrated a high ability to eradicate bacteria after 30 min. These composites showed no or very limited leaching of copper ions into the aqueous phase both in the presence and in the absence of a bacterial suspension. Immobilized copper and cuprous oxide nanoparticles can be used for batch or continuous disinfection of water.

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A novel photodegradation approach for the efficient removal of natural organic matter (NOM) from water

Cited by 20 publications

References 32 publications

Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

Photocatalytic Oxidation of Natural Organic Matter in Water

LLDPE Composites with Nanosized Copper and Copper Oxides for Water Disinfection

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