A New Approach for Removing Anionic Organic Dyes from Wastewater Based on Electrostatically Driven Assembly

详细信息    查看全文

• 作者：Sira Sansuk ; Somkiat Srijaranai ; Supalax Srijaranai
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：June 21, 2016
• 年：2016
• 卷：50
• 期：12
• 页码：6477-6484
• 全文大小：485K
• 年卷期：0
• ISSN：1520-5851

文摘

A conceptually new approach for an efficient removal of anionic organic dyes from wastewater using layered double hydroxides (LDHs) through their formation is presented. Acid yellow 25 (AY25) was used as anionic organic dye model molecules. As a result of the electrostatic induction, the removal mechanism involved a concurrent incorporation of AY25 molecules into the interlayer of LDHs during their structural arrangement, where Mg²⁺ and Al³⁺ ions were utilized to construct the base of LDHs in an alkaline solution. It was found that the molar stoichiometry of all precursors was a key factor affecting the removal efficiency. Within 5 min removal time, this method still maintained high removal efficiency of over 97% and provided a removal capacity of ∼186 mg g^–1, comparable to that of other LDH-based methods. Also, almost complete dye recovery was simply achieved by anionic exchange with common anions (Cl^–, NO₃^–, and CO₃^2–). Additionally, the present technique is straightforward, cost-effective, and environmentally friendly since it avoids the synthesis step of sorbents, thus significantly saving time, chemicals, and energy. Hence, this strategy not only exhibits the alternative exploitation of LDHs, but also provides new insights into the removal of contaminants from wastewater.