Novel collector design and optimized photo-fenton model for sustainable industry textile wastewater treatment

Abstract

Textile industry wastewater containing toxic dyes and high COD poses environmental hazards and requires treatment before discharge. This study addresses the challenge of treating complex textile wastewater using a novel integrated system. The system combines sedimentation, screening, adsorption, and an optimized solar photo-Fenton process to provide a sustainable treatment solution. A novel parabolic collector with a larger absorber tube diameter enhances solar radiation utilization at lower catalyst concentrations. This design is versatile, treating all types of wastewaters, especially those that contain colors, smells, solid and suspended materials, in addition to its importance for the treatment of difficult substances that may be present in industrial and sewage wastewaters that are difficult to dispose of by traditional treatment methods. Multivariate experiments optimized key photo-Fenton parameters (pH, catalyst dose, etc.) achieving significant pollutant removal (85% COD, 82% TOC, complete color) under specific conditions (pH 3, 0.2 g/L Fe(II), 1 mL/L H₂O₂, 40 °C and 100 L/h flow rate after 60 min irradiation). Kinetic modeling revealed second-order reaction kinetics, and multivariate regression analysis led to the development of models predicting treatment efficiency based on process factors. The key scientific contributions are the integrated system design combining conventional and advanced oxidation technologies, novel collector configuration for efficient utilization of solar radiation, comprehensive process optimization through multivariate experiments, kinetic modeling and predictive modeling relating process factors to pollutant degradation. This provides an economical green solution for textile wastewater treatment and reuse along with useful design guidelines. The treatment methodology and modeling approach make valuable additions for sustainable management of textile industry wastewater.

Keywords: Classical processes; Developed oxidation processes; Free hydroxyl radicals; Integrated unit; Solar photo-fenton process; Wastewater treatment.

Figure 1

(a) and (b). Schematic diagram and a photo of the integrated designed experimental set-up.

Figure 2

The components of concentrating parabolic collector (CPC): (a) Reactor tube, (b) CPC mirror, and (c) CPC reflector.

Figure 3

Influence of solar light on % colour removal: [Fe(II) = 0.2 gm/L, H₂O₂ = 1mL/L, temperature = 40 °C, and flow rate = 100 L/h].

Figure 4

Influence of solar light on % removal of COD and TOC: [Fe(II) = 0.2 gm/L, H₂O₂ = 1mL/L, temperature = 40 °C, irradiation time = 60 min, and flow rate = 100 L/h].

Figure 5

Influence of pH on % removal of colour, COD and TOC: [Fe(II) = 0.2 gm/L, temperature = 40 °C, irradiation time = 60 min, H₂O₂ = 1mL/L, and flow rate = 100 L/h].

Figure 6

Influence of initial Fe(II) concentration on % removal of colour, COD and TOC: [pH = 3, temperature = 40 °C, irradiation time = 60 min, H₂O₂ = 1mL/L, and flow rate = 100 L/h].

Figure 7

Influence of H₂O₂ amount on % removal of colour, COD and TOC: [pH = 3, temperature = 40 °C, irradiation time = 60 min, Fe(II) = 0.2 gm/L, and flow rate = 100 L/h].

Figure 8

Influence of temperature on % removal of colour, COD and TOC: [pH = 3, H₂O₂ = 1mL/L, irradiation time = 60 min, Fe(II) = 0.2 gm/L, and flow rate = 100 L/h].

Figure 9

ln [C_t] vs. irradiation time at different temperatures [pH = 3, H₂O₂ = 1mL/L, Fe(II) = 0.2 gm/L, and flow rate = 100 L/h].

Figure 10

Arrhenius plot of COD removal [pH = 3, H₂O₂ = 1mL/L, Fe(II) = 0.2 gm/L, and flow rate = 100 L/h].

Figure 11

Influence of dye solution flow rate on % removal of colour, COD and TOC: [pH = 3, H₂O₂ = 1mL/L, irradiation time = 60 min, Fe(II) = 0.2 gm/L, and temperature = 40 °C].

Figure 12

Reaction rate of 2500 ppm initial COD at ideal processing factors (a) 1st order kinetic model, (b) 2nd order kinetic model [pH = 3, H₂O₂ = 1mL/L, irradiation time = 60 min, Fe(II) = 0.2 gm/L, dye solution flow rate = 100 L/h , and temperature = 40 °C].

Figure 13

Experimentally determined colour removal % with the expected values.

Figure 14

3D surface plot depicting the expected colour removal % in relation to: (a) H₂O₂ amount and Fe(II) concentration, (b) pH and wastewater flow rate.

Figure 15

Experimentally determined COD removal % with the expected values.

Figure 16

3D surface plot depicting the expected COD removal % in relation to: (a) H₂O₂ amount and Fe(II) concentration, (b)pH and wastewater flow rate.

Figure 17

Experimentally determined TOC removal % with the expected values.

Figure 18

3D surface plot depicting the expected TOC removal % in relation to: (a) H₂O₂ amount and Fe(II) concentration, (b) pH and wastewater flow rate.