钢铁冶金烧结烟气脱硫含铊废水的处理
发布时间：2018-07-27 15:53
【摘要】：铊作为一种剧毒且是人体内非必需的稀有重金属元素,其对生物体乃至环境都有非常大的危害作用,在自然界中,主要是以较为稳定的Tl+形式存在于水体中,目前,仅在我国报道有独立的铊矿床存在。铊在生活中的应用非常广泛,但其毒性却不容小觑。共沉絮凝法是通过加入一些化学药剂而达到去除废水中杂质的目的;吸附法则是利用具有吸附效果的吸附剂将废水中的杂质由液相转移至固相;离子交换主要是通过杂质离子与表面带有相同电荷的离子交换树脂进行离子交换而达到净化的目的。本文主要是分别采用共沉絮凝法,吸附法,离子交换三种方法去除废水中的铊。共沉絮凝法是以湖南省某钢铁冶金烧结烟气脱硫含铊废水为研究对象,研究了Na2S,Na2CO3,聚丙烯酰胺(PAM)对废水中铊的去除,且结合废水中铊的去除率及经济成本确定最优药剂配比;吸附法则是以模拟含铊废水为研究对象,通过一系列的吸附实验,探讨了铊(Ⅰ)在粉末活性炭上的吸附行为和主要影响因素,并且对吸附动力学,吸附热力学进行了初步研究。离子交换法亦是以模拟含铊废水为研究对象,对其主要影响因素进行了考察,找出了最佳处理条件。研究结果如下:采用共沉絮凝法处理1 L钢铁冶金烧结烟气脱硫含铊废水的药剂最优配比为3 mL质量分数为10%的Na2S溶液,5 g无水Na2CO3固体0.5 mL质量分数为1%的絮凝剂PAM,絮凝剂可加速絮状物的沉降;采用活性炭吸附去除废水中的铊宜在碱性条件下进行,吸附平衡时间为2 h,吸附动力学研究结果表明活性炭吸附铊的行为更符合Lagergren伪二级动力学模型,等温吸附线研究表明Freundlich模型能比Langmuir模型更好地描述活性炭吸附铊的行为,吸附热力学的研究结果表明活性炭吸附铊是自发进行的反应,该过程放热,因此,宜在低温条件下进行吸附实验,溶液中共存离子的存在会严重影响活性炭对废水中铊的吸附,且去除率随着共存离子浓度的增加而大幅度降低;采用阳离子交换树脂去除废水中的铊宜在偏碱性条件下进行,平衡时间为1.5 h,当废水中初始铊离子浓度低于1 mg/L时,使用阳离子交换树脂可将废水中的铊全部去除,溶液中的共存离子对离子交换树脂除铊的影响较大,另外,离子交换树脂除铊是一个吸热反应,因此,适当升温有利于阳离子交换树脂对铊的处理。经济性分析研究结果表明,采用共沉絮凝法不仅处理效果优于吸附法及离子交换法,且所需成本远远小于吸附法及离子交换法。
[Abstract]:Thallium, as a highly toxic and non-essential heavy metal element in human body, has great harm to organism and environment. In nature, thallium mainly exists in water body in the form of TL. Independent thallium deposits have been reported only in China. Thallium is widely used in life, but its toxicity is not to be underestimated. The method of co-settling flocculation is to remove impurities in wastewater by adding some chemical agents, and the adsorption rule is to transfer impurities from liquid phase to solid phase by using adsorbent with adsorption effect. Ion exchange is achieved by ion exchange between impurity ions and ion exchange resins with the same charge on the surface. In this paper, the removal of thallium in waste water by co-settling flocculation method, adsorption method and ion exchange method respectively. The coprecipitation flocculation method was used to study the removal of thallium from iron and steel metallurgical flue gas desulphurization containing thallium wastewater in Hunan province. The removal of thallium from wastewater by Na _ 2S _ 2CO _ 3 and polyacrylamide (PAM) was studied, and the optimum proportion was determined by combining the removal rate and economic cost of thallium in wastewater. A series of experiments were carried out to study the adsorption behavior of thallium (鈪，
本文编号：2148332
[Abstract]:Thallium, as a highly toxic and non-essential heavy metal element in human body, has great harm to organism and environment. In nature, thallium mainly exists in water body in the form of TL. Independent thallium deposits have been reported only in China. Thallium is widely used in life, but its toxicity is not to be underestimated. The method of co-settling flocculation is to remove impurities in wastewater by adding some chemical agents, and the adsorption rule is to transfer impurities from liquid phase to solid phase by using adsorbent with adsorption effect. Ion exchange is achieved by ion exchange between impurity ions and ion exchange resins with the same charge on the surface. In this paper, the removal of thallium in waste water by co-settling flocculation method, adsorption method and ion exchange method respectively. The coprecipitation flocculation method was used to study the removal of thallium from iron and steel metallurgical flue gas desulphurization containing thallium wastewater in Hunan province. The removal of thallium from wastewater by Na _ 2S _ 2CO _ 3 and polyacrylamide (PAM) was studied, and the optimum proportion was determined by combining the removal rate and economic cost of thallium in wastewater. A series of experiments were carried out to study the adsorption behavior of thallium (鈪，
本文编号：2148332
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