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固定化血红蛋白吸附水中NO2~-性能的研究
Study on Adsorbing Nitrite in Water by Immobilized Hemoglobin
【作者】 赵茂俊;
【导师】 冯易君;
【作者基本信息】 四川大学 , 环境科学, 2001, 硕士
【摘要】 亚硝酸盐广泛存在于土壤、水、食品中,它可使人体正常的血红蛋白氧化成高铁血红蛋白,失去血红蛋白在体内输送氧的功能,从而导致人体中毒。而且它还能与二级胺生成N—亚硝胺化合物,N-—亚硝胺化合物是一类强致癌物。因此,我们有必要研究水中亚硝酸盐的去除方法。 我们创新地采用固定化血红蛋白处理水中NO2。本实验中,我们选择了三种方法固定血红蛋白,并在此基础上作了适当的改进:a.在氧化纤维法固定血红蛋白中,我们将棉短绒改为脱脂棉,使材料更易得。b.PVA包埋法固定血红蛋白中,我们将PVA的浓度加到15%,而且加入了2%的海澡酸钠,使制得的PVA小球在水中长时间浸泡也不会变软、溶解。C.戊二醛交联法固定血红蛋白中,我们将加入的血红蛋白的浓度改为120g/L,加入的各物质的体积比改进为:21.5mL Hb:3.5ml磷酸盐缓冲溶液:1.5ml50%的戊二醛。经改进后,固定化血红蛋白对NO的吸附效果更好。 综合三种固定化血红蛋白对NO的吸附效果、固定过程中血红蛋白的损失程度及血红蛋白的固定量、固定化血红蛋白制作过程的繁简等因素考虑,我们选择了戊二醛交联法固定血红蛋白,并进一步考察了一系列因素如:浓度、温度、pH值、平衡时间、干扰离子等对固定化血红蛋白吸附NO的影响,确定了吸附的最佳条件:即温度为25℃、pH=6.5,反应5小时时吸附率达90%以上。饱和吸附量为37.14mg/g。 通过定性实验,提出了血红蛋白吸附NO的机理为NO与血红蛋白中的亚铁离子发生氧化还原反应,将亚铁离子氧化成三价铁。根据这一吸附机理我们独创地选用抗坏血酸作为洗脱剂,洗脱的最佳条件是:抗坏血酸的浓度为0.5mol/L,pH=1。吸附NO达饱和的固定化血红蛋白经洗脱处理后,重复使用十次左右。吸附率始终保持在90%以上。 在动态吸附实验中,我们以05Illlfllllll的速度将NOS溶液通过装有Z639固定化血红蛋白的吸附柱,NOS的去除率高于90%。我们以此条件处理三种实际废水均有较好的效果,尤其是处理被NO污染了的饮用水(NO的含量为10mg/L*吸附率为97.2%,当流出吸附柱的净化水体积超过150nil时,水中残余的NO低于0.swt。 本研究表明,固定化血红蛋白能有效地吸附水中的NOi。因血红蛋白和洗脱剂抗坏血酸均对人体无毒害、无污染,所以用固定化血红蛋白处理被污染了的生活用水具有实用价值。用固定化血红蛋白处理水中的NOi是一种新方法,国内外未见报道。
【Abstract】 Nitrite is widely existed in soiK water and food, It can change hemoglobin(Hb) into methaemoglobin (Fe31) in men’s body. Methaemoglobin can’t carry oxygen, so men will be poisoned because of lacking oxygen. Nitrite also react with amine to form product of N-nitrosoamines, and N-nitrosoamines is a carcinogenic substance,. So it is necessary to study the method of removing nitrite hi water.Useing immobilized hemoglobin to remove nitrite is a new method which hasn’t been reported by now. we test three different materials to immobilize hemeglobin: Oxycellulose P and glutaraldehyde, we find that it is the best method for hemoglobin immobilized by glutaraldhyde to adsorb nitrite. This method is very simple and does not result in the loss of hemoglobin.We aslo study a series of factors which might influence the adsorption of nitrite(Such as concentration^ temperature pH, reaction time and the co-existent ions ect). When temperature keeps at 25 . pH is 6.5 and the immobilized hemoglobin adsorb nitrite for five hours, the removal rate could be up to 90%; the adsorption balance time is 12 hours; maximun adsortion quantity of NO^ is 37.14mg/g. Vc can be used to elute the nitrite adsorbed by immobilized hemoglobin, Which is effective in the condition of pH=l. After the immobilized hemoglobin be repeatedly used for ten times, adsorption rate is still up to 90%.In dynamic test, We let nitrite solution pass through glass column at a speed of 0.5ml/min. The adsorption rate is up to 90%. When we purify the wastewater containing 1 Omg/L NO in this method, the concentration of NOz in purifying ater is below 0.8mg/L, at the time of the volume of elutant going beyound 150ml.Experiment proved that it is utility for us to use immobilized hemoglobin to treat nitrite wastewater.
【Key words】 immobolized hemoglobin; nitrite; wastewater treatment; elution;
- 【网络出版投稿人】 四川大学 【网络出版年期】2002年 01期
- 【分类号】X703
- 【下载频次】104