【摘要】 利用LDH合成原理 ,提出了即时合成层状双氢氧化物去除Cr(Ⅵ )的新方法 .其基本原理是 ,在废水处理中由于Mg2 +、Al3 +水解共沉淀形成LDH ,Cr(Ⅵ )阴离子优先进入LDH结构层间平衡结构电荷 ,从而使Cr(Ⅵ )阴离子以LDH沉淀的形式被去除 .这一原理已为模拟废水实验和沉淀物结构分析证实 .研究结果表明 ,影响处理效果的因素是Mg/Al比值、pH值以及Cr(Ⅵ )浓度 ,当 pH值为 8 5～ 9、Mg/Al为 1∶1～ 2∶1时Cr去除率最高 ,Mg、Al利用率也比较高 ,出水水质满足工业排放要求 ,从而显示这种废水处理技术具有非常好的效果更多还原

【Abstract】 The objective of this work was to investigate the efficiency and factors impacting of removal Cr(Ⅵ) from wastewater by layer double hydroxide synthesizing in situ. Principle of the method may be described as follow: Mg 2+ and Al 3+ hydrolysis and forms Mg/Al LDH by adding Mg 2+ , Al 3+ and NaOH into wastewater containing Cr(Ⅵ), Cr(Ⅵ) anions are selectively intercalated into interlayer of LDH to balance positive structural charge. While Mg 2+ and Al 3+ co precipitates and forms LDH, the Cr(Ⅵ) in wastewater is removal by settle of LDH synthesizing in situ, which are confirmed by analysis of X ray diffraction on settle and chemical analysis on aqueous. The results indicate that factors of impacting on efficiency of removal Cr(Ⅵ) include in amount of adding Mg 2+ and Al 3+ , Mg/Al ratio, pH and concentration of Cr(Ⅵ) in wastewater. The maximal removal efficiency of Cr(Ⅵ) can be reached when pH values are between 8.5 and 9, and Mg/Al ratios are between 1∶1 and 2∶1, meanwhile, Mg and Al added can be taken good use of. This technology has present extraordinary efficiency of wastewater treatment.更多还原