Discharges of disposal of the textile industry into general water bodies can cause deterioration of aquatic ecosystems and adversely affect human health. The objective of this study is to assess the Congo red dye decolourization by immobilized Aspergillus niger obtained from textile dye wastewater. The effect of experimental parameters like pH 5, contact time (30 h) and initial dye concentration (50 mg/L) on the process of decolourization of dye in the aqueous solution was revealed 97%. The optimum dye decolourization efficiency of immobilized Aspergillus niger using central composite design was found to be 98.97%, obtained were pH 5, initial concentration 50 mg/L, temperature 30 °C and contact time 36 h. Isotherm studies showed that the experimental data better fitted with to Langmuir isotherm, the Freundlich isotherm and Tempkin isotherm for decolourization dye by immobilized Aspergillus niger. It was found that the decolourization was best evaluated by a pseudo-second-order model rather than the pseudo-first-order model. The maximum monolayer adsorption capacity of immobilized Aspergillus niger was resulted as 4325 mg/g at 303 K (R² = 0.994). The value of separation factor (RL) from Langmuir equation and Freundlich constant (n) indicated on favorability of bioabsorption. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated and the negative value of ΔH° (− 29,671 kJ/mol) for corresponding initial Congo red dye concentrations: 50 mg/L, in the solution indicated that the bioabsorption was of exothermic reaction.. The UV–Vis and FTIR analysis of metabolites after treatment confirmed that the decolourization. Phytotoxicity test confirmed that was less toxic than original dye. The reusability of the immobilized Aspergillus niger was repeated with seven cycles and removal efficiency ranged from 98 to 42%.

将纺织工业的废物排放到一般的水体中会导致水生生态系统恶化，并对人类健康产生不利影响。这项研究的目的是评估从纺织染料废水中获得的固定化黑曲霉对刚果红染料的脱色性能。结果表明，pH 5，接触时间（30 h）和初始染料浓度（50 mg / L）等实验参数对染料在水溶液中脱色的影响为97％。固定化黑曲霉的最佳染料脱色效率使用中心复合设计，发现其为98.97％，pH为5，初始浓度为50 mg / L，温度为30°C，接触时间为36 h。等温线研究表明，固定化黑曲霉对兰缪尔等温线，Freundlich等温线和Tempkin等温线进行脱色染料的实验数据更好。已经发现，脱色最好通过伪二阶模型而不是伪一阶模型进行评估。固定化黑曲霉的最大单层吸附容量为303 K（R ²  = 0.994），为4325 mg / g 。Langmuir方程的分离因子（RL）和Freundlich常数（n）表示对生物吸收的好感度。计算了诸如ΔG°，ΔH°和ΔS°的热力学参数，并且溶液中相应初始刚果红染料浓度为50 mg / L时ΔH°的负值（-29,671 kJ / mol）表明生物吸收为放热反应。处理后代谢物的UV-Vis和FTIR分析证实了脱色。植物毒性试验证实其毒性低于原始染料。固定的黑曲霉重复使用了七个循环，其去除效率为98％至42％。