Degradation of tetracycline by solar photo‐Fenton: Optimization and application in pilot photoreactor

Abstract

The objective of this study is to analyze the photodegradation of the antibiotic tetracycline by the solar photo-Fenton process. The optimal conditions were obtained in a 2 2 (2 × 2) factorial design with the following input variables: reaction time and catalyst concentration (ferrous ion [Fe 2+ ]). After statistical analysis using the Statistica 7.0 software, the optimal conditions determined, time = 120 min and Fe 2+ = 166.81 mg/L, were applied in a pilot scale photoreactor, resulting in an 88.7% removal of the drug. In addition, in this stage we studied the reaction kinetics, biodegradability, and phytotoxicity of the products generated by the process. In the kinetic study, a constant of 1.82 × 10 −2 min −1 was obtained. For this constant, a reaction time of 38.16 min is required for the initial tetracycline concentration to be reduced by 50%. The biodegradability tests indicated a gradual increase in the five-day biological oxygen demand/chemical oxygen demand ratio over time. The phytotoxicity tests showed an 18.5% decrease in the inhibition rate of the root growth of lettuce seedlings, indicating that the treatment applied reduces the toxicity of the substance. K E Y W O R D Sbiodegradability, photo-Fenton, photoreactor, phytotoxicity, solar photocatalysis, tetracycline

Doxycycline Removal by Solar Photo-Fenton on a Pilot-Scale Composite Parabolic Collector (CPC) Reactor

“…The kinetic constant rate K (min −1 ) was determined from the slope of the linear plot of Equation (10), where 𝐶 is the concentration at moment t and 𝐶 is the starting concentration. The highest value of K (0.0143 min −1 ), close to the K in the degradation of tetracycline by SPF in the pilot photoreactor [37], corresponded to 0.1 mM Fe 2+ with an R 2 value of 0.99. These findings are consistent with the classic Fenton reaction, in which excess Fe 2+ ions serve as hydroxyl radical scavengers, as shown in Equation (9).…”

“…The kinetic constant rate K (min −1 ) was determined from the slope of the linear plot of Equation (10), where C t is the concentration at moment t and C 0 is the starting concentration. The highest value of K (0.0143 min −1 ), close to the K in the degradation of tetracycline by SPF in the pilot photoreactor [37], corresponded to 0.1 mM Fe 2+ with an R 2 value of 0.99. The degradation of DOX during the solar photo-Fenton oxidation process was examined under various oxidant concentrations (3 mM, 4 mM, and 5 mM) at pH 3.0 and at a constant ferrous concentration of 0.1 mM in order to determine the optimum H 2 O 2 dose.…”

Degradation of Oxytetracycline and Chlortetracycline by Fenton Process

“…Biological treatment methods are insufficient in antibiotic removal due to their resistant and toxic structures. Advanced oxidation methods are widely used in the treatment of wastewater containing recalcitrant and non-biodegradable organic compounds (Cahino et al, 2018). Advanced oxidation methods are based on the formation of hydroxyl radicals and can oxidize a wide range of organic matter to CO2 and H2O (Sun et al, 2009).…”

Degradation and mineralization of tetracycline by Fenton process

“…There are many studies using the Fenton process for the removal of different drugs [11][12][13][14][15][16]. Also, different processes such as UV, UV/H 2 O 2 , UV/persulfate, photo-Fenton, solar photo-Fenton, sono-Fenton, ozonation have been tried in tetracycline removal [17][18][19][20][21][22]. In this study, it was aimed to systematically optimize the operating parameters such as pH, Fe 2+ concentration, H 2 O 2 concentration, reaction time and precipitation time in the degradation and mineralization of tetracycline by Fenton process.…”