Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
Laboratory for Bioremediation Research, Unit Operations Lab, Department of Biotechnology, Kumaraguru College of Technology, Coimbatore, India.
Chemosphere. 2021 Apr;268:128809. doi: 10.1016/j.chemosphere.2020.128809. Epub 2020 Oct 28.
Valorization of waste phytomass into valuable components provide new functionality to these biowastes and annul problems associated with their safe disposal. In this study, date palm (Phoenix dactylifera) coir (DPC) waste was tested for its toxic hexavalent chromium (Cr(VI)) ions biosorption. The DPC biosorbent was subjected to SEM, EDX, FTIR, TGA and N adsorption/desorption characterization studies. Results showed that the cellulose-rich DPC surface contained mesopores with a wide number of functional groups and possessed suitable surface attributes for Cr(VI) ions sequestration. Batch biosorption tests established the Cr(VI) ions sequestration potential of the DPC biosorbent with a maximum chromium removal efficiency of 87.2% for a 100 ppm initial feed concentration at pH 2, dosage 0.3 g, temperature 30 °C, contact time 60 min and agitation speed 100 rpm. Langmuir isotherm fitted well (R = 0.9955) with the experimental data while the kinetic analysis showed that Cr(VI) ions sequestration by DPC followed the pseudo-second order model. Biosorption thermodynamics revealed the exothermic nature and low-temperature preference for the effective binding of chromium ions on DPC. Regeneration of the biosorbent using NaOH wash showed a nearly steady Cr(VI) ions removal efficiency (with a loss <10%) by the DPC till four recycle runs. Economic analysis showed a very low production cost of $1.09/kg for the DPC biosorbent with a total cost of $4.36/m for a scale-up batch process wastewater treatment plant. Thus, a low-cost, effectual and sustainable biosorbent for effective treatment of Cr(VI) ions polluted water streams has been reported.
将废弃植物生物质转化为有价值的成分，为这些生物废物赋予新的功能，并解决与安全处理相关的问题。在这项研究中，我们测试了椰枣（Phoenix dactylifera）纤维（DPC）废料对六价铬（Cr(VI)）离子的生物吸附能力。DPC 生物吸附剂经过 SEM、EDX、FTIR、TGA 和 N 吸附/解吸特性研究。结果表明，富含纤维素的 DPC 表面含有中孔，具有大量的功能基团，并具有适合 Cr(VI)离子螯合的表面特性。批量吸附实验确定了 DPC 生物吸附剂对 Cr(VI)离子的螯合潜力，在初始进料浓度为 100ppm、pH 值为 2、剂量为 0.3g、温度为 30°C、接触时间为 60min 和搅拌速度为 100rpm 的条件下，最大铬去除效率为 87.2%。Langmuir 等温线很好地拟合了实验数据（R=0.9955），而动力学分析表明，DPC 对 Cr(VI)离子的螯合遵循准二级模型。吸附热力学表明，Cr(VI)离子与 DPC 的有效结合是放热的，且低温有利于结合。使用 NaOH 洗涤再生生物吸附剂，DPC 的 Cr(VI)离子去除效率几乎保持稳定（损失<10%），直到进行了四次循环运行。经济分析表明，DPC 生物吸附剂的生产成本非常低，为每公斤 1.09 美元，对于规模放大的批处理废水处理厂，总成本为每立方米 4.36 美元。因此，我们报道了一种低成本、有效且可持续的生物吸附剂，可有效处理 Cr(VI)离子污染的水流。
