Low cost UVA-LED as a radiation source for the photo-Fenton process: a new approach for micropollutant removal from urban wastewater

Abstract

Light Emitting Diode (LED) technology has matured sufficiently to be considered as an alternative UVA radiation source in photoreactors. Currently, low energy consuming LEDs with a wide range of wavelengths and radiant flux are readily available. In this study, UVA-LEDs were used as a radiation source for the photo-Fenton process as tertiary treatment. The water matrix used was a simulated secondary effluent doped with 200 μg L of the pesticide acetamiprid (ACTM) due to its recalcitrant nature. All experiments were carried out in a LED-box reactor at pH 2.8. The main purpose of this research was to gain some insight into the relationships among energy supply, LED consumption, UVA irradiance and reaction rate. The effect of LED wavelength on energy efficiency for ACTM degradation was studied by varying the iron concentration and liquid depth. Three wavelengths (365, 385 and 400 nm) and two iron concentrations (5 and 11 mg L) for two different liquid depths (5 and 15 cm) were evaluated in order to obtain more energy efficient conditions. The results suggest that while the wavelength of 365 nm with 11 mg Fe L was the best condition for ACTM degradation, the wavelength of 385 nm had slower kinetics, but higher energy efficiency.

Micropollutant removal in real WW by photo-Fenton (circumneutral and acid pH) with BLB and LED lamps

“…On the other hand, the costs associated to energy consumption could be decreased using light-emitting diodes (LEDs) as a source of radiation. In recent years, the studies with the use of LEDs in AOPs have increased [32,33] because LEDs show many advantages such as low power consumption, long lifetime (up to 26,000 h), no overheating and no mercury content [32][33][34][35][36][37][38][39][40][41].…”

A calibrated UV-LED based light source for water purification and characterisation of photocatalysis

“…A variety of LEDs have been used as a light source for photocatalytic reactions [13]. Obra et al [14] examined a UVA-LED driven photo-Fenton process for micropollutant removal for urban wastewater. High power UVA-LEDs has also been used by Betancourt-Buitrago et al [15] in photoreactors for degradation of methylene blue, who provided a detailed overview of LEDs used in the photodegradation of dyes.…”

LED irradiated photo-Fenton for the removal of estrogenic activity and endocrine disruptors from wastewater treatment plant effluent

“…Besides, a recent study confirmed the removal of estrogenic activity (< 0.007 ng L −1 of equivalents of estradiol represented as EQ-E2) from wastewater after treatment by modified photo-Fenton at near neutral pH (Rivas Ibáñez et al 2017). Although some studies have already assessed the performance of LED as a radiation source in photo-Fenton aiming at the removal of CECs (Carra et al 2015;de la Obra et al 2017;Davididou et al 2017;Chávez et al 2019), most of these studies are conducted either in synthetic matrixes or in wastewater samples spiked with target contaminants and none of them have yet investigated the impact of LED irradiated photo-Fenton upon estrogenic activity of real municipal wastewater. In this way, the novelty pertaining to this work is related to the unprecedented evaluation of estrogenic activity present in real WWTPE during the photo-Fenton process using LED as an environmentally friendly irradiation source.…”

“…LED has no toxic constituents and shows longer lifetime when compared to artificial Hg lamps, thus reducing the generation of hazardous solid waste. In addition, it has higher energy efficiency cutting back on greenhouse gas emissions (Carra et al 2015;Chen et al 2017;de la Obra et al 2017;Nardelli et al 2017).…”