【作者】 杨涛；

【导师】 刘发强；

【作者基本信息】 兰州交通大学 ， 化学工程（专业学位）， 2017， 硕士

【摘要】 工业污水及外排水中氯离子含量较高,若处理不达标排放,则会对水体自身平衡造成影响,严重时还会危害地下水和饮用水源。目前,工业污水及外排水中氯离子的处理方法主要有沉淀盐法,蒸发浓缩法,电化学法,离子交换法,氧化还原法等。上述方法中,沉淀盐法不仅处理效果好且方法简便易行,但由于投入与产出存在较大差距,且一直处于基础研究阶段,工业应用较少;蒸发浓缩法一般用于处理浓度较高的氯离子污水,但能耗较高,设备要求高;电吸附法适于处理浓度较低的氯离子污水,但要达到更好的效果,得通过升高电压或增大极板面积,上述方法均会提高成本和能耗;离子交换法是一种很早就采用的氯离子污水处理方法,采用时间较长,技术较为成熟,但离子交换树脂价格较高,再生时运行费用高以及再生过程较为复杂,且其表面微生物容易增殖;氧化还原法的水耗和电耗较大,成本较高。故需找到一种经济有效、成本低廉、环境友好的除氯方法。大多数工业污水及外排水中除了含有高浓度的Cl^-还含有大量的SO₃^2-,以及在污水处理过程中一部分SO₃^2-转变成的SO₄^2-。因此,在去除污水中Cl^-的同时,还应去除其中的SO₃^2-和SO₄^2-。否则,不仅对正常工业生产有一定影响,还会危害周围的生态环境。经调查研究发现,利用超高石灰铝法,向含氯污水中加入CaO和NaAlO2,Ca2+和Al3+与Cl^-反应形成溶解度极小的钙铝氯层状化合物Ca4Al2Cl2（OH）12,是一种简便且经济有效的去除氯离子方法;利用氧化钙沉淀法可有效去除SO₃^2-,即SO₃^2-和Ca2+可生成CaSO3,除去SO₃^2-。实验首先确定超高石灰铝法的n（Ca）:n（Al）:n（Cl）=12.0:3.6:1.0,研究了高速和中低速搅拌下去除Cl^-的实验条件。高速搅拌下,搅拌速度5000rpm、搅拌时间10min、反应温度20℃,Cl^-去除率达86.09%;中低速搅拌下,搅拌速度80rpm、搅拌时间20min、反应温度20℃,Cl^-去除率达73.67%。去除SO₃^2-的实验条件为n（Ca）:n（S）=4.6:1.0,搅拌速度100rpm、反应温度20℃、搅拌时间20min,SO₃^2-的初始浓度为9387.00mg/L时,SO₃^2-的去除率可达98.67%。实验进一步探究了SO₃^2-在不同浓度时的去除效果;总反应时间和Cl^-浓度高低对Cl^-和SO₃^2-去除效果的影响;SO₃^2-和SO₄^2-对Cl^-去除效果的影响;最后,在去除Cl^-和SO₃^2-实验过滤所得沉淀中添加一部分CaO和NaAlO2,使二者达到实验的起始总用量,当SO₃^2-初始浓度不同时,探究其对原溶液中该两种离子的去除情况。更多还原

【Abstract】 The chloride content in industrial wastewater and external drainageis is relatively high,if not dispose and achieve standard to discharge directly,it will have an impact on the water balance and be a serious harm to groundwater and drinking water resources.At present,chlorine ion treatment methods are precipitation salt,evaporation,electrochemical method,ions exchange,oxidation reduction and so on.In these methods,salt precipitation method is effective and easy to operate,but it has a large gap between input and output,so it has been in the basic research stage and less industrial applications;evaporation concentration method is generally used to deal with the high chloride concentration wastewater,but the energy consumption is high and higher requirement for equipment;electro adsorption method is suitable for the wastewater with low concentration chlorine ion,in order to achieve a better effect,it should be increased the voltage or the area of the plate,but the two methods will increase cost and energy consumption;ions exchange is a chloride ion treatment method very early,it has been used for a long time,the technology is more mature,but the cost of ions exchange resin is too high,the regeneration process is more complex and high cost of operation,microorganisms on its surface are easy to proliferate;oxidation reduction method consumes much water and electricity,needs a lot of cost.Therefore,we should find a economic and effective method for the removal of chlorine,which is cheap and environmentally friendly.Most of the industrial wastewater and external drainageis contain high concentration of Cl^-,a lot of SO₃^2-,and a part of SO₃^2-charge into SO₄^2-in the process of wastewater treatment.So,after to remove Cl^-in wastewater,we should remove SO₃^2-and SO₄^2-.Otherwise,it will affect the normal industrial production and cause certain hazards to the ecological environment.Through investigation and study,I use the ultra high aluminum lime method,adding CaO and NaAlO2 into chlorine wastewater,Ca2+ 、 Al3+ and Cl^-reacte to form the minimum solubility of calcium aluminum chloride layered compound which is Ca4Al2Cl2（OH）12,it is a simple and economical method for removing chlorine.I use the CaO precipitation method on removal of SO₃^2-effectively,that is to say,SO₃^2-and Ca2+ generate CaSO3 and remove SO₃^2-.At first,I determine the ultra high aluminum lime method,s n（Ca）:n（Al）:n（Cl）is 12.0:3.6:1.0,study on the experimental conditions of high speed and low speed to remove the Cl^-.Under high speed condition,the stirring speed is 5000 rpm,the stirring time is 10 min and the reaction temperature is 20℃,the Cl^-removal rate up to86.09%.Under low and medium speed mixing condition,the stirring speed is 80 rpm,the stirring time is 20 min and the reaction temperature is 20℃,the Cl^-removal rate up to 73.67%.The experimental conditions for the removal of SO₃^2-is n（Ca）:n（S）=4.6:1.0,100 rpm of stirring speed,20℃of reaction temperature,20 min of stirring time.When the initial concentration of SO₃^2-is 9387.00mg/L,the SO₃^2-removal rate up to 98.67%.Furthermore,the experiment explore the effect on different concentration of SO₃^2-removal;the removal effect of the Cl^-and SO₃^2-by total reaction time and concentration of Cl^-;the removal effect of the Cl^-by SO₃^2-and SO₄^2-;at last,I add a part of CaO and NaAlO2 in the removal of Cl^-and SO₃^2-experimental precipitation,enabled CaO and NaAlO2 to achieve the initial total amount of experiment,when the original SO₃^2-at different initial concentration,to explore the removal of the two ions in original solution.更多还原