School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
J Hazard Mater. 2010 May 15;177(1-3):420-7. doi: 10.1016/j.jhazmat.2009.12.049. Epub 2009 Dec 16.
Our recent work reported that a mixed adsorbent with natural clay materials and lime demonstrated an enhanced capacity and efficiency to remove anionic Congo Red dye from wastewater. This study aims to investigate the removal kinetic and mechanisms of the mixed materials involved in the decolourisation of the dye to maximise their prospective applications for industrial wastewater treatment. The experimental results showed that dye removal was governed by combined physiochemical reactions of adsorption, ion-exchange, and precipitation. Ca-dye precipitation contributed over 70% total dye removal, followed by adsorption and ion-exchange. The dye removal kinetic followed the pseudo-second-order expression and was well described by the Freundlich isotherm model. This study indicated pH was a key parameter to govern the removal mechanisms, i.e. adsorption/coagulation at acidic pH and precipitation at basic condition. Yet, the overall removal efficiency was found to be independent to the operation conditions, resulting in more than 94% dye removal. This work revealed that the mixed clays and lime can be applied as alternative low-cost adsorbents for industrial wastewater treatment.
我们最近的工作报道称，一种由天然粘土材料和石灰组成的混合吸附剂具有增强的从废水中去除阴离子刚果红染料的能力和效率。本研究旨在探讨混合材料在染料脱色过程中的去除动力学和机制，以最大限度地提高其在工业废水处理中的应用前景。实验结果表明，染料的去除受吸附、离子交换和沉淀等多种物理化学反应的共同控制。Ca-染料沉淀对总染料去除的贡献超过 70%，其次是吸附和离子交换。染料去除动力学符合准二级表达式，并很好地符合 Freundlich 等温模型。本研究表明 pH 是控制去除机制的关键参数，即在酸性 pH 下吸附/凝聚，在碱性条件下沉淀。然而，发现整体去除效率与操作条件无关，导致染料去除率超过 94%。这项工作表明，混合粘土和石灰可用作替代的低成本工业废水处理吸附剂。
