Degradation Characteristics of Color Index Direct Blue 15 Dye Using Iron-Carbon Micro-Electrolysis Coupled with H2O2

Abstract

Currently, many industrial dyes are discharged into the environment in China, leading to serious water pollution. However, synthetic organic dyes in industrial effluents cannot be degraded by conventional wastewater treatment methods. Consequently, it is necessary to develop new environmentally friendly technologies to completely mineralize these non-biodegradable compounds. In this study, 300 mg/L typical Color Index (CI) Direct Blue 15 (benzidine disazo) in simulated dye wastewater was degraded by iron-carbon micro-electrolysis coupled with H2O2 to explore its decolorization, total organic carbon (TOC) removal rate, and degradation characteristics. Under the optimal degradation conditions (Fe/C = 2:1, pH = 3, 60-min reaction, 2 mL/L H2O2 (added in three aliquots), 300 mg/L dye), the TOC removal rate and the level of dye decolorization attained 40% and 98%, respectively. In addition, the degradation kinetics indicated that the iron-carbon micro-electrolysis process coupled with H2O2 followed first-order reaction kinetics. A degradation pathway for CI Direct Blue 15 was proposed based on the analysis results of treated wastewater obtained using UV-Vis spectrophotometry and gas chromatography–mass spectrometry (GC-MS). This study provides an efficient and economical system for the degradation of non-biodegradable pollutants.

Electrochemical Degradation of Industrial Dyes in Wastewater through the Dissolution of Aluminum Sacrificial Anode of Cu/Al Macro-Corrosion Galvanic Cell

“…It is then followed by the degradation of benzene ring in the dye molecule to finally undergo complete or partial mineralization process. These effects could be visualized by absorbance changes within the UV-VIS spectrum for the selected wavelength ranges, namely: 350–600, 265–350 and 200–265 nm, correspondingly [ 46 , 47 , 48 , 49 , 50 , 51 ].…”

“…It is strongly believed that the latter effect is a consequence of accumulation of the reaction intermediates from the first electrodegradation stage in bulk of the analyzed solution. Last, pigments electrodegradation process ( Figure 7 c and Figure 8 c) is related to mineralization, where a vast number of relatively simple (e.g., maleic, formic and acetic acid, aldehydes, ammonia, nitrogen oxides and finally carbon dioxide molecule) or more complex chemical compounds could be formed, such as: anti-pentanoic acid and others [ 48 , 49 , 50 , 51 ]. It has to be stated that for the Disperse Red 167, its removal involved a combination of two steps, namely: surface electrooxidation and electrocoagulation processes, yielding 98 and 99% of the dye removal after 900 and 3600 s, respectively ( Figure 7 d).…”

Factors Affecting the Simultaneous Removal of Nitrate and Reactive Black 5 Dye via Hydrogen-Based Denitrification

“…Specifically, NO 3 -N and NO 2 -N concentrations were determined as previously described by APHA [24], while the concentration of RB-5 was determined using a standard curve, of which several known concentrations of RB-5 were plotted against their detected absorbance at λ max 597 nm [25]. Thereafter, the DRE of the RB-5 dye was calculated based on the Lambert-Beer law [26]. The linear equation used for RB-5 determination in this study was y = 0.0214x + 0.0201 (R 2 = 0.9980).…”

An Integrative Approach to Study Bacterial Enzymatic Degradation of Toxic Dyes

“…Using nanocomposites as photocatalysts also have shown positive results in decolorizing titan yellow and methyl orange dyes (Kumar et al, 2020). Coupling hydrogen peroxide H 2 O 2 with the iron-carbon micro-electrolysis is a new eco-friendly method and has shown positive results in decolorizing Direct Blue 15 dye (Yang et al, 2018). A very different approach of coupling inductively coupled plasma mass spectrometry (ICP-MS) and time-of-flight mass spectrometry (Q-TOF-MS) was performed by researchers to decolorize the Reactive Orange 107 dye under anaerobic and aerobic conditions (Frindt et al, 2017).…”