Naslov
UV-LED advanced oxidation processes for the efficient removal of organic micropollutants from water

Autori
Bertagna Silva, Danilo

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Fakultet kemijskog inženjerstva i tehnologije

Mjesto
Zagreb

Datum
21.07

Godina
2022

Stranica
179

Mentor
Babić, Sandra ; Buttiglieri, Gianluigi

Ključne riječi
advanced oxidation processes ; photocatalysis ; photoreactor design ; contaminants of emerging concern ; ultraviolet light-emitting diodes ; water treatment

Sažetak
The recent developments of ultraviolet light- emitting diodes (UV-LEDs) open up new horizons for advanced oxidation processes (AOPs) for water treatment such as photocatalysis. In this work, the performance of UV-LED-based AOPs for the removal of organic micropollutants (OMPs) in water was investigated in a multitude of scenarios. Initially, the light profiles of a labscale photoreactor were simulated using different UV-LED arrays to investigate light intensity and homogeneity. A design of experiments (DoE) was made to access which variables have more significance for the apparent kinetic rate (kapp) and electrical energy per order consumption (EEO) of the antibiotic ciprofloxacin, and the optimal photoreactor design was defined. The simultaneous and individual degradation of 5 OMPs (all in the EU Watch List of Contaminants of Emerging Concern of 2020) was studied in sub sequential DoEs investigating the significance of numerous parameters (concerning both the photoreactor design and matrix composition) on relevant process outputs. The influence of simultaneous wavelength use on EEO values was investigated. Finally, a transformation product (TP) analysis was carried out to identify which molecules are generated for different scenarios, and their possible correlation with toxicity levels. Results show that a higher light homogeneity inside a cylindrical photoreactor is not necessarily achieved with more LEDs around it. The DoEs gave accurate models to predict outputs. LEDs’ controlled periodic illumination was able to increase kapp values for photocatalytic experiments, but this was not followed by a benefit in EEO. Disparate responses of different OMPs to each situation suggest that the optimized treatment of choice will depend on matrix composition, target pollutant reactivity and required standards of the final effluent. The use of UV-C for photocatalysis is not recommended due to screening effects. The EEO values of photocatalysis remain unfeasible for practical purposes. The use of simultaneous wavelength did not lead to a decrease on EEO values. Nevertheless, improvements can be foreseen due to the unique features of UV-LEDs and their exponential performance enhancements in the last few years, which should have a direct impact on process costs. Transformation products for different reaction scenarios were identified, but their correlations with toxicity remain unclear due to possible synergistic effects and undetected TPs.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Interdisciplinarne tehničke znanosti

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