Bicarbonate-Hydrogen Peroxide System for Treating Dyeing Wastewater: Degradation of Organic Pollutants and Color Removal

Abstract

The textile industry is a global economic driving force; however, it is also one of the most polluting industries, with highly toxic effluents which are complex to treat due to the recalcitrant nature of some compounds present in these effluents. This research focuses on the removal of Chemical Oxygen Demand (COD), color, Total Organic Carbon (TOC), and Ammoniacal Nitrogen (N-NH3) on tannery wastewater treatment through an advanced oxidation process (AOPs) using sodium bicarbonate (NaHCO3), hydrogen peroxide (H2O2) and temperature using a central composite non-factorial design with a surface response using Statistica 7.0 software. All experiments used a 500 mL reactor with 300 mL of tannery wastewater from a company in Cúcuta, Colombia. The physicochemical characterization was done to determine the significant absorbance peaks about the color in the wavelengths between 297 and 669 nm. Statistical analysis found that the concentration of NaHCO3 affects the removal of color and N-NH3; however, it did not affect COD and TOC. The optimal process conditions for removing the different compounds under study were: NaHCO3 1 M, H2O2 2 M, and 60 °C, with efficiencies of 92.35%, 31.93%, 68.85%, and 35.5% N-NH3, COD, color, and TOC respectively. It can be concluded that AOPs using H2O2 and NaHCO3 are recommended to remove color and N-NH3.

A Phytochemical Approach to the Removal of Contaminants from Industrial Dyeing Wastewater

“…Table 3 shows the physicochemical characterization of the dyeing effluents. The physicochemical characterization of the dyeing effluents shows low biodegradability (0.29 BOD/DQO), a phenomenon similar to other reported studies [36,39,42]; similarly, the concentrations of nitrogen compounds (nitrates, nitrites, and ammonia nitrogen) were similar to the average ranges reported in other studies (Table 3). Phosphate concentrations are within the range of other studies, where average phosphate concentrations of 10-45.5 mg × L −1 were reported.…”

“…Total protein content was measured according to Slocombe et al [36]. Three milliliters of 24% trichloroacetic acid (TCA) wase added to a Falcon tube containing a filter with known biomass.…”

“…Dyeing wastewater characterization is essential for ensuring compliance with environmental regulations and protecting public health. In recent years, several studies have been conducted to analyze the composition of dyeing wastewater and develop effective treatment methods [36][37][38]. Table 3 shows the physicochemical characterization of the dyeing effluents.…”

“…Dyeing effluents can vary in their composition and concentration of contaminants, depending on the processes and chemicals used during the dyeing process [39,43]. However, several studies have pointed to common physicochemical characteristics of these effluents: in terms of pH, depending on the use of different salts, bases, and acids, the pH can vary between acidic values (<5) and alkaline values (>9) [36,44]; the COD concentration can range from 750 to 13,000 ppm, and most authors cite BOD/CBD ratios of 0.15-0.4. These results are like those found in this work, indicating a higher concentration of recalcitrant compounds that are not readily biodegradable by microorganisms; therefore, the search for microorganisms that can degrade this type of wastewater is a biotechnological potential not only for the treatment of these wastewaters, but also for their use.…”

Enhanced UV/H2O2 System for the Oxidation of Organic Contaminants and Ammonia Transformation from Tannery Effluents

“…AOPs have become very important in recent years in treating wastewater-containing dyes [12], especially from the tanning industry [13]. Strongly oxidizing radicals, primarily the free hydroxyl radical (OH), are produced and used in these procedures with the goal of selectively reducing stubborn contaminants to a less hazardous state.…”