亚氧化钛电极的制备及其去除铜绿微囊藻性能的研究

发布时间：2018-04-21 15:31

本文选题：电化学 + 高级氧化　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：中国的城市化进程越来越快,导致生活污水与工业废水的产生量每日增加。但在之前人们的环保意识并没有很强。许多生活污水与工业废水未经处理就随意的排放到自然界中,造成自然水体超过其自净能力。水中氮磷元素严重超标,造成水体大面积富营养化。而引起水体富营养化的重要原因就是水体内的藻类过度繁殖,在湖水或其他水域里大量的爆发。而藻类在自然水体中的爆发通常会给人们饮用水的供应带来难以估计的影响。藻类本身生长释放在水体中的一系列物质都会引起水生生物和人类的众多疾病。对水生生态系统造成难以估计的破坏与危害。在淡水富营养化中,主要的藻类是铜绿微囊藻。船体在行使过程中通常会有压载水,当压载水中含有这种藻类时,船体到达另一片水域将压载水排出时就会给另一片水域引入这种藻类。当另一片水域的水质条件如果适宜铜绿微囊藻繁殖就有极高的潜在风险引起另一片水域的富营养化。因此在本研究中,使用一种简便的电化学反应器,探究不同实验条件下利用电化学高级氧化作用杀灭水中的铜绿微囊藻(经常被称为蓝藻)的效果。该电化学反应器结构组成为:阳极为亚氧化钛电极材料,阴极为不锈钢网。在实验中,将含有铜绿微囊藻的藻悬浮液(藻类浓度为1.3-1.1×1010个/L),置于电流密度为1 mA/cm2至10mA/cm2下进行电化学高级氧化处理,反应时间为2h。在反应过程中我们每隔0.5 h进行取样,监测蓝藻细胞密度、叶绿素a的含量、水体的p H值和电导率以及水质的COD和溶液中其他大分子物质(蛋白质、腐殖质等)的变化。在电流密度为10 mA/cm2时,经过前30 min电化学高级氧化的处理后,铜绿微囊藻的细胞密度下降的非常迅速。藻密度从起始的1.3×1010个/L下降到6.9×109个/L。经过120 min处理后,藻类细胞浓度由1.3×1010个/L下降到6.2×109个/L。根据实验可以得出结论,铜绿微囊藻的数量变化和光密度值的变化是与所施加的电流密度和处理时间成正相关的。并且通过扫描电子显微镜观察,可以清晰的看见,在经过电化学氧化处理后铜绿微囊藻的细胞膜受到了严重的破坏,使其细胞内的细胞质大量的外泄。由于细胞损坏,导致叶绿素a从细胞内外渗到溶液中,才可以被电化学反应所氧化进行矿化作用,从而得到去除。在所施加电流密度为10 mA/cm2时,藻类的叶绿素的去除率接近90%。并且由于电化学反应导致水体的p H和电导率有了明显的变化,更加加速了叶绿素a的去除效率。并且处理后的藻类几乎没有再次生长的可能,当所施加的电流密度为10mA/cm2时,仅仅处理15 min后,将处理后的藻类按照无菌操作的方法重新培养在适宜条件下培养。连续监测8天早溶液的光密度值变化(藻类浓度)。通过实验我们发现铜绿微囊藻细胞并没有任何生长和生存的迹象。光密度值一直呈现下降状态,并且整个溶液也由原来的淡绿色变成了浑浊的淡黄色。以上实验充分的证明了,电化学高级氧化可以成功并且高效的对引起富营养化的重要对象—铜绿微囊藻进行有效的杀灭。并且可以在短时间内使藻类细胞失去活性。这充分说明了电化学高级氧化在富营养化水体治理净化过程中拥有着广阔的应用前景和使用价值。
[Abstract]:The process of urbanization in China is getting faster and faster, which leads to the daily increase in the production of domestic sewage and industrial wastewater. But the awareness of environmental protection is not very strong before. Many domestic sewage and industrial waste water are discharged into nature at will, causing natural water to exceed its self purification capacity. The important reason for eutrophication in water body is that the important reason for the eutrophication of water body is the excessive reproduction of algae in the water body and a large number of outbreaks in lake water or other waters. The outbreak of algae in the natural water body usually brings inestimable influence on the supply of drinking water. The algae itself is released in the body of the water body. Material can cause many diseases of aquatic organisms and human beings. It causes inestimable damage and harm to aquatic ecosystems. In freshwater eutrophication, the main algae is Microcystis aeruginosa. The hull is usually loaded with ballast water during the process of exercise. When this kind of algae is contained in the ballast water, the ship will reach the other water to press the ballast water. A simple electrochemical reactor is used to explore the use of advanced electrochemical oxidation under different experimental conditions to explore the use of electrochemical advanced oxidation in this study. The effect of the Microcystis (often called cyanobacteria) in the killing of water. The electrochemical reactor structure is: the anode is a titanium dioxide electrode material and the cathode is stainless steel. In the experiment, the algal suspension containing Microcystis aeruginosa (1.3-1.1 x 1010 /L) is placed under the current density of 1 mA/cm2 to 10mA/cm2. The electrochemical advanced oxidation treatment, the reaction time was 2h. during the reaction process, we sampled every 0.5 h, monitoring the density of cyanobacteria, the content of chlorophyll a, the P H value and electrical conductivity of the water body, the COD of water quality and the other large molecular substances (protein, humus, etc.) in the solution. At the current density of 10 mA/cm2, the first 30 min After electrochemical advanced oxidation, the cell density of Microcystis aeruginosa declined very rapidly. The algae density decreased from 1.3 x 1010 /L to 6.9 * 109 /L. after 120 min treatment, and the algal cell concentration decreased from 1.3 x 1010 /L to 6.2 x 109 /L. according to the experiment, the quantitative change and light density of Microcystis aeruginosa could be concluded. The change in the value is positively related to the current density and processing time applied. And by scanning electron microscopy, it can be clearly seen that the cell membrane of Microcystis aeruginosa has been severely damaged after electrochemical oxidation, making the cytoplasm of the cells in a large amount of leakage. Due to cell damage, the chlorophyll a is caused. The mineralization can be removed by the oxidation of the cell from the cell to the solution. The removal rate of chlorophyll is close to 90%. when the current density is 10 mA/cm2, and the electrochemical reaction leads to the obvious change in the P H and electrical conductivity of the water body, which accelerates the removal of chlorophyll a. Efficiency. And the algae after treatment had almost no possibility of regrowing again. When the applied current density was 10mA/cm2, only 15 min was treated, the treated algae were retrained under the aseptic operation under suitable conditions. The change of the light density value of the 8 day early solution (algae concentration) was continuously monitored. The Microcystis aeruginosa cells do not have any signs of growth and survival. The value of light density has been declining, and the whole solution has also changed from the original light green to the turbid yellowish yellow. The above experiments are fully demonstrated that the electrochemical advanced oxidation can be successful and highly effective in producing eutrophication microcapsules. The algae can be effectively killed and the algal cells can be lost in a short time. This shows that the advanced electrochemical oxidation has a broad application prospect and use value in the treatment and purification process of eutrophic water.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O646.5;X52

【参考文献】