Investigation the effect of intensity and direction of light on the removal of reactive blue dye from simulated wastewater using photo-Fenton oxidation under UV irradiation: Batch and continuous methods

Abstract

This study aims to remove reactive blue dye (R.B) from simulated wastewater by utilizing advanced oxidation processes (AOPs) using a photo-Fenton (UV/H2O2/Fe+2) system. A photo-reactor containing four fixed UV lamps had been employed in a batch and continuous mode under the effect of several operating variables (dosage of H2O2; dosage FeSO4; pH; temperature; irradiation time). Response surface methodology (Box–Behnken design) and Portable Statgraphics Centurion statistical software were used to design the experiments and conducting the mathematical correlation of the required responses as well as the interaction effects among variables. The optimal conditions of the operating variables; dosage hydrogen peroxide, ferrous sulphate, pH, temperature and irradiation time were 78 ppm, 20 ppm, 3, 40°C and 90 min, respectively which give 84.82% of removal efficiency. Then, the effect of light intensity and distance from a UV source were studied at optimum conditions in the batch photo-reactor where the highest dye removal efficacy was obtained at a light intensity of 24 w and a distance of 15cm. For continuous system, two operating conditions were studied, the direction of the light radiation and the flow rate which proofed that the dye removal efficiency decreased with an increase of flow rate and the top direction compared to the side direction of the light where the removal percentage of (R.B) was 100% for the flow rate of 10 ml/min while it was 84.16% for a flow rate of 50 ml/min. The results show that the photo-Fenton method is an effective treatment method of Wastewater containing dyes.

A Comprehensive Approach to Azo Dichlorotriazine Dye Treatment: Assessing the Impact of Physical, Chemical, and Biological Treatment Methods through Statistical Analysis of Experimental Data

“…Notably, the percentage of color removal increased with prolonged irradiation time, as this facilitated the generation of more free radicals resulting from multiple reactions. These findings align with Tabarek A. Sajjad's 2020 [37] research.…”

“…However, increasing the flow rate from 20 to 80 mL/min resulted in a decrease in color removal percentage, indicating an inverse relationship between flow rate and dye removal efficiency. This can be attributed to the fact that a higher flow rate leads to a shorter exposure time of the polluted solution to the UV lamp, which requires a decrease in the amount of H 2 O 2 to form more hydroxyl radical (OH • ), as supported by previous studies [37,39].…”

“…The effectiveness of the photo-Fenton process relies on the composition and recovery rates of OH • , which can vary depending on the organic substrate and duration of irradiation [37,38]. To determine the optimal duration for COD removal, the impact of various irradiation times (ranging from 10 to 60 min) on photo-Fenton treatment was examined, at the following conditions, pH = 3, catalyst dose = 0.4 mg/L, H 2 O 2 = 1 mL/L, 20 mL/min flow rate, initial dye concentration = 0.75 gm/L, and 75-watt light intensity.…”

“…As shown in Figure S8, the 150-watt lamp achieves 80% COD removal for 30 min and the 75-watt lamp achieves the same COD removal % but for 60 min. This is in consequence of more OH • radicals being generated with increased UV light intensity in the photo-Fenton process causing more organic matter to degrade in a shorter period [22,24,25,37].…”

Optimization of adsorption of methyl orange from aqueous solution by magnetic CoFe2O4/ZnAl-layered double hydroxide composite using response surface methodology

“…Dyes are widely used in several industries such as plastics, textile, paper, printing, and food industries as colorants [1].…”