伊利石和钠蒙脱石对溴化乙锭的吸附机理研究  

Adsorption Mechanism of Illite and Sodium Montmorillonite on Ethidium Bromide

作　　者：周敬彪 王文东 张博翔 陈志文 ZHOU Jing-biao;WANG Wen-dong;ZHANG Bo-xiang;CHEN Zhi-wen(School of Environmental and Municipal Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西西安710055 [2]西安交通大学人居环境与建筑工程学院,陕西西安710049

出　　处：《中国给水排水》2021年第5期79-85,共7页China Water & Wastewater

摘　　要：黏土矿物由于其独特的阳离子交换能力而表现出良好的吸附性能,在废水处理中有着广泛应用。溴化乙锭作为分子实验室中常用的核酸染料,其强烈的诱变性会对人体造成不可逆的伤害。利用2∶1型伊利石和2∶1型钠蒙脱石两种不同性质的黏土吸附溴化乙锭,探究吸附行为及吸附机理。结果表明,伊利石和钠蒙脱石吸附溴化乙锭过程均符合Langmuir等温吸附模型和伪二级动力学方程,二者对溴化乙锭的吸附容量受控于阳离子交换能力,分别为0.10 mmol/g和1.09 mmol/g。进一步发现,溴化乙锭在伊利石上的吸附主要发生在材料外表面,受H^(+)和Na^(+)对吸附点位竞争的影响较为显著;其在钠蒙脱石上的吸附则主要发生在层间,受环境pH值和离子竞争的影响较小,表明其与钠蒙脱石的亲和力高。因此,不同结构黏土矿物表现出不同的吸附行为。Clay minerals exhibit good adsorption properties due to their unique cation exchange capacity and are widely used in wastewater treatment.Ethidium bromide is a commonly used nucleic acid dye in molecular laboratories,and its strong mutagenicity can cause irreversible damage to the human body.Ethidium bromide was adsorbed by two different types of clays,which were 2∶1 type illite and 2∶1 type sodium montmorillonite,and the adsorption behavior and adsorption mechanism were explored.The adsorption process of illite and sodium montmorillonite on ethidium bromide was consistent with Langmuir isothermal adsorption model and pseudosecondorder kinetic equation,and their adsorption capacities were controlled by cation exchange capacity,which were 0.10 mmol/g and 1.09 mmol/g,respectively.It was further found that the adsorption of ethidium bromide on illite mainly occurred on the outer surface of the material,and the influence of H^(+)and Na^(+)on the adsorption site competition was significant.The adsorption of ethidium bromide on sodium montmorillonite occurred mainly in the interlayer spacing and was less affected by environmental pH and ionic competition,indicating that it had a high affinity with ethidium bromide.Therefore,clay minerals with different structures exhibited different adsorption behaviors.

关 键 词：溴化乙锭 伊利石 钠蒙脱石 阳离子交换 层间吸附 

分 类 号：HQ52