Sono-assisted enhanced adsorption of eriochrome Black-T dye onto a novel polymeric nanocomposite: kinetic, isotherm, and response surface methodology optimization

Nowadays, the colored wastewater generated primarily from dyeing and textile industries loaded with synthetic dyes are considered to be one of the key reason for water pollution. However, the remarkable development in material science resulted to fabrication of highly efficient composite materials for effective remediation of such wastewaters. In recent times, polymer matrix-based nanocomposites have turned out to be an outstanding domain of research considering the potential application of polymeric nanocomposite in several important areas including environmental remediation. In this work, the fabrication of a novel iron oxide/polyaniline polymeric nanocomposite (Iron oxide-PANI-PNC) was reported and its sono-assisted adsorptive potential was studied for a toxic anionic dye, Eriochrome Black-T (EBT). This study clears that pure iron oxide has strong pH dependency and it shows maximum dye adsorption only at highly acidic conditions. However, Iron oxide-PANI-PNC could reduce this pH dependency significantly and this polymeric nano-composite shows enhanced dye removal in the wide range of pH from 2.0 to 5.0. Langmuir isotherm model was best fitted to EBT dye adsorption experimental data onto Iron oxide-PANI-PNC with a maximum monolayer adsorption capacity of 285.71<b> </b>mg/g. Sono-assisted EBT dye adsorption process has achieved an enhanced removal efficiency of 93% as compared to magnetic stirring (65%) and batch stirring (60%). Response surface methodology (RSM) based optimization revealed that maximum EBT dye uptake adsorption of 99.61% at Iron oxide-PANI-PNC dose of 0.8 g/L, sonication time of 27 min, and initial EBT dye concentration of 30 mg/L.

当前，主要来源于印染纺织行业、富含合成染料的有色废水，被认为是造成水体污染的关键诱因之一。然而，材料科学领域的显著进步推动了高效复合材料的制备，可用于此类废水的高效修复治理。近年来，聚合物基纳米复合材料（polymer matrix-based nanocomposites）已成为极具前景的研究热点领域——这是因为聚合物纳米复合材料在包括环境修复在内的诸多重要领域具备应用潜力。本研究报道了一种新型氧化铁/聚苯胺聚合物纳米复合材料（Iron oxide-PANI-PNC）的制备方法，并探究了其超声辅助吸附处理有毒阴离子染料铬黑T（Eriochrome Black-T, EBT）的性能。本研究表明，纯氧化铁具有较强的pH依赖性，仅在强酸性条件下才能实现最优的染料吸附效果。而氧化铁-聚苯胺聚合物纳米复合材料则可显著降低这种pH依赖性，该复合材料在pH 2.0至5.0的宽范围内均表现出更优的染料去除效果。针对氧化铁-聚苯胺聚合物纳米复合材料的EBT染料吸附实验数据，朗缪尔等温线模型（Langmuir isotherm model）拟合效果最优，其最大单分子层吸附容量可达285.71 mg/g。超声辅助EBT染料吸附工艺的去除效率可达93%，相较于磁力搅拌（65%）和间歇搅拌（60%）有显著提升。基于响应面法（Response Surface Methodology, RSM）的优化结果显示，当氧化铁-聚苯胺聚合物纳米复合材料投加量为0.8 g/L、超声时间为27 min、初始EBT染料浓度为30 mg/L时，可实现最高99.61%的EBT染料吸附去除率。