The electrocoagulation (EC) of Congo red dye-containing wastewater was investigated, focusing on the optimization of operational parameters and process mechanism. The EC was conducted using iron electrodes and utilizing Congo Red (CR) dye as a model pollutant. Response surface methodology (RSM) was used to investigate the effect of operational parameters (initial dye concentration, pH and inter-electrode distance) and optimize the process. To provide insight into the process mechanism, quantum chemical analysis and FTIR were utilized. The process achieved 89% and 97% COD and color removal respectively under optimum conditions (1000 mg/L initial dye concentration, pH 3 and 3 cm inter-electrode distance). The electrical energy required to achieve the optimum COD removal was estimated to be about 36.9 kJ. The quantum analysis showed that CR with HOMO energy of −5.58 eV and Fe³⁺ LUMO energy of −15.09 eV exhibit electron donating and electron accepting tendency respectively. In addition, Fe³⁺ shares its LUMO with the HOMO of HO– due to the lower energy gap of −19.47 eV, which leads to the formation of monomeric coagulant such as Fe(OH)₃ and the subsequent polymeric flocculants including Fe₂(OH)₂⁴⁺ and Fe₆(OH)₁₅³⁺. The FTIR analysis of the sludge indicates the presence of coagulant species i.e. Fe(OH)₃, Fe(OH)²⁺, Fe(OH)₂⁺ and Fe₂(OH)₂⁴⁺ that are generated from the EC. The findings of this study show that quantum chemical analysis and RSM are suitable for investigating the mechanism and optimization of EC as applied to textile effluents.

对含刚果红染料的废水进行电凝（EC）研究，重点是优化操作参数和工艺机理。EC使用铁电极和刚果红（CR）染料作为模型污染物进行。响应表面方法（RSM）用于研究操作参数（初始染料浓度，pH和电极间距离）的影响并优化工艺。为了提供对过程机理的洞察力，利用了量子化学分析和FTIR。在最佳条件下（1000 mg / L初始染料浓度，pH 3和3 cm电极间距离），该工艺分别实现了89％和97％的COD和脱色。实现最佳COD去除所需的电能估计约为36.9 kJ。-15.09 eV的³⁺ LUMO能量分别表现出给电子和受电子趋势。此外，由于-19.47 eV的较低能隙，Fe ³⁺与HO-的HOMO共享其LUMO，这导致形成单体凝结剂，如Fe（OH）₃以及随后的包括Fe ₂（ OH）₂ ⁴⁺和Fe ₆（OH）₁₅ ³⁺。污泥的FTIR分析表明凝结剂物质的存在，即铁（OH）₃，铁（OH）²⁺，铁（OH）₂ ⁺和Fe ₂（OH）₂ ⁴⁺从EC产生的。这项研究的结果表明，量子化学分析和RSM适用于研究EC用于纺织废水的机理和优化。