Energy efficient BPA degradation through Fetched-Ni-Sn-C-N-TiO2 nano-layered thin film reactors

Autor: Tolga Tunçal
Rok vydání: 2020
Předmět:
Zdroj: Environmental Technology & Innovation. 20:101174
ISSN: 2352-1864
DOI: 10.1016/j.eti.2020.101174
Popis: Increasing wastewater generation rates and micro-pollutant levels in environmental matrices constrain energy-efficient and fast control technologies. In this study, different optical and geometrical photocatalytic reactor (PCR) design have been investigated experimentally using BPA molecule as a model pollutant. N-TiO2, Ni-N-TiO2, Sn-N-TiO2, Ni-Sn-C-N-TiO2 and F etched -Ni-Sn-C-N-TiO2 nano-layered thin films (TFs) have been produced and employed as immobilized nano-catalysts. An ultrasound-assisted fluorine (F) etching method was applied to Sn and Ni co-doped TFs. The synthesized TFs were characterized by SEM-EDX, AFM, XPS, FT-IR and UV–Vis spectroscopies. Three different types of PCRs with different geometrical and optical design were operated using different light sources, wavelengths and technologies. A box type photoreactor, vertical and horizontal coated quartz tubular reactors (CQTRs) were fabricated and their performances were evaluated considering BPA degradation kinetics and unit energy consumption figures ( ξ , kJ energy used mg−1 BPA removed ). Vis, UV A, UV C lamps and SMD 5050 blue (450 nm) and UV (365 nm) LEDs were employed as irradiation sources to initiate photocatalytic reactions. The highest pseudo first-order reaction rate (k) and the lowest ξ value were obtained by F etched -Sn-Ni-C-N-TiO2, positioned in vertical type reactor under UV LED irradiation as 20.5 min − 1 and 56 kJ mg−1 BPA removed respectively. Whereas, the highest BPA degradation rate (k) and the lowest ξ value for the box type reactor under 257 nm UV C irradiation were estimated as 20.3 min−1 and 1581 kJ mg−1 BPA removed respectively for F etched -Sn-Ni-C-N-TiO2. Although similar reaction rates were obtained for both reactor types, energy consumption was lowered approximately 28-fold in the developed vertical positioned reactor system in addition to several other benefits. While UV LED based-PCR yielded elevated levels of BPA removal efficiency, 257 nm UV C irradiation did not contribute to BPA degradation when positioned vertically. Furthermore, obtained experimental results also revealed that F etched -Sn-Ni-C-N-TiO2 has significant potential to function under solar irradiation.
Databáze: OpenAIRE
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