Department of Zoology, Adhiyaman Arts and Science College for Women, Uthangarai, Krishnagiri - 635 207, Tamil Nadu, India.
Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore - 641 043, Tamil Nadu, India.
Environ Res. 2022 Nov;214(Pt 2):113859. doi: 10.1016/j.envres.2022.113859. Epub 2022 Jul 14.
The present study was focused on the removal of Reactive Black 5 (RB5) from aqueous solution using pre treated Aspergillus flavus as a biosorbent. Pre-treatment of fungal biomass with 0.1 M sodium hydroxide facilitated the removal of dye effectively when compared to untreated fungal biomass. Optimum biosorption conditions for RB5 removal was determined as a function of dye concentration (50-400 mg/L), biosorbent concentration (100-500 mg/L), incubation time (1-7hrs), pH (3-8) and temperature (20-50 °C). At the optimum conditions, the maximum removal efficiency of RB5 achieved by NaOH pretreated A. flavus was 91%. The dye removal was studied kinetically and it obeys the pseudo-second order model and the experimental equilibrium data well fitted the Langmuir isotherm indicating monolayer adsorption of dye molecules on the biosorbent. The thermodynamic parameters such as a change in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated and negative values of ΔG suggested that the dye removal process was spontaneous at all temperatures. Furthermore, the values of ΔH revealed that the adsorption process was endothermic. Recovery of RB5 from the fungal biomass was effective using 0.1 M NaCO as an eluent. The interaction of adsorbate with biosorbent was analyzed using UV-Vis and FT-IR spectroscopy, SEM and XRD analyses. Phytotoxicity and microbial toxicity studies revealed the non-toxic nature of the treated dye solution. Hence, the fungal biomass pretreated with NaOH was efficient in decolorizing RB5 as well as composite raw industrial effluent generated from dyeing industries.
本研究旨在使用预处理的黄曲霉作为生物吸附剂从水溶液中去除活性黑 5（RB5）。与未处理的真菌生物质相比，用 0.1 M 氢氧化钠预处理真菌生物质可更有效地去除染料。RB5 去除的最佳生物吸附条件是作为染料浓度（50-400 mg/L）、生物吸附剂浓度（100-500 mg/L）、孵育时间（1-7 小时）、pH（3-8）和温度（20-50°C）的函数来确定。在最佳条件下，NaOH 预处理黄曲霉对 RB5 的最大去除效率为 91%。研究了染料的去除动力学，它符合准二级模型，实验平衡数据很好地拟合了 Langmuir 等温线，表明染料分子在生物吸附剂上的单层吸附。计算了热力学参数，如自由能变化（ΔG）、焓变（ΔH）和熵变（ΔS），ΔG 的负值表明在所有温度下染料去除过程都是自发的。此外，ΔH 的值表明吸附过程是吸热的。用 0.1 M NaCO 作为洗脱剂从真菌生物质中有效回收 RB5。用紫外-可见光谱、傅里叶变换红外光谱、SEM 和 XRD 分析了吸附物与生物吸附剂的相互作用。植物毒性和微生物毒性研究表明处理后的染料溶液无毒。因此，用 NaOH 预处理的真菌生物质在对 RB5 进行脱色以及对来自染整工业的复合原始工业废水进行脱色方面都很有效。
