微孔曝气氧化亚硫酸镁实验研究

发布时间：2018-06-15 21:15

  本文选题：镁法脱硫 + 亚硫酸镁　； 参考：《大连海事大学》2017年硕士论文

【摘要】：与传统的钙法脱硫相比,镁法脱硫具有脱硫效率高,投资少,占地面积小,运行费用低等优点。镁法脱硫副产物-亚硫酸镁不但会造成脱硫系统腐蚀、磨损和堵塞,而且造成脱硫废水COD值增大。亚硫酸镁性质不稳定,在一定条件下会分解为S02和氧化镁,对环境造成二次污染。将亚硫酸镁强制氧化为稳定性强,溶解度大的硫酸镁成为研究热点。本文将微孔曝气技术应用于亚硫酸镁氧化中,以期推动镁法脱硫技术的应用推广。采用微孔曝气器在不同水深、不同空气流量的条件下进行清水充氧实验得到:随着空气流量的增大,氧总转移系数和充氧能力逐渐增大,但增至一定值后变化不大。增加水深可增大氧总转移系数并且促进充氧能力,并且空气流量越大,增加水深产生的促进效果越明显。氧利用率随水深增大而逐渐增大;随着空气流量的增大而线性下降,并且随水深增大,下降趋势越显著。通过研究亚硫酸镁浓度、曝气水深、空气流量、pH值和温度对亚硫酸镁氧化反应的影响得到:氧化反应速率随浓度增大先升高后下降,在0.1 mol/L左右处达最大;曝气水深对氧化反应影响不大;增大空气流量有利于提高反应速率;氧化反应应在低pH值下进行;提高反应温度可加快氧化反应速率,最佳反应温度为50℃。通过正交试验得到曝气水深为1.05 m,氧化100 L亚硫酸镁溶液的最佳反应条件为:亚硫酸镁浓度0.15mol/L,空气流量1.5m3/h,pH值7.0-7.5。
[Abstract]:Compared with the traditional calcium desulphurization, magnesium desulphurization has the advantages of high desulfurization efficiency, less investment, small occupation area and low operating cost. Magnesium sulfite, the by-product of magnesium desulfurization, will not only cause corrosion, abrasion and blockage of desulphurization system, but also increase the COD value of desulphurization wastewater. Magnesium sulfite is unstable and decomposes into S02 and MgO under certain conditions, which causes secondary pollution to the environment. The forced oxidation of magnesium sulfite to magnesium sulfate with strong stability and high solubility has become a research hotspot. In this paper, microporous aeration technology is applied to magnesium sulfite oxidation in order to promote the application of magnesium desulphurization technology. The oxygen transfer coefficient and oxygen capacity of microporous aerator were increased with the increase of air flow rate under different water depth and different air flow rate. However, the oxygen transfer coefficient and oxygen capacity increased gradually with the increase of air flow rate, but little change was found after increasing to a certain value. The increase of water depth can increase the total oxygen transfer coefficient and promote the oxygenation capacity, and the greater the air flow rate, the more obvious the effect of increasing the water depth. The oxygen utilization ratio increases gradually with the increase of water depth, and decreases linearly with the increase of air flow rate, and with the increase of water depth, the decreasing trend is more obvious. The effects of magnesium sulfite concentration, water depth of aeration, air flow rate, pH value and temperature on the oxidation reaction of magnesium sulfite were studied. The results showed that the oxidation rate increased first and then decreased with the increase of concentration, and reached the maximum at 0.1 mol / L; The water depth of aeration has little effect on the oxidation reaction; the increase of air flow rate is beneficial to increase the reaction rate; the oxidation reaction should be carried out at low pH value; the reaction rate can be accelerated by increasing the reaction temperature, and the optimum reaction temperature is 50 鈩，

本文编号：2023680