陶瓷平板膜处理含锰地下水的试验研究

发布时间：2018-04-29 09:50

本文选题：地下水 + 锰　；参考：《沈阳建筑大学》2014年硕士论文

【摘要】：地下水作为生活饮用水水源具有水质较好、不易受污染、比较安全可靠和卫生等优点。地下水中铁、锰超标会引起健康、经济等一系列问题,锰的氧化还原电位高于铁,因此,Mn2+比Fe2+难以氧化,我国《生活饮用水卫生标准》要求锰含量应在0.1 mg/L以下,本文着重探讨了陶瓷瓶平板膜在地下水除锰的应用及处理效果。本文第一部分采用动态过滤的试验方式,着重对曝气接触氧化法-陶瓷平板膜联合除锰工艺、空气接触氧化法-陶瓷平板膜联合除锰工艺、高温催化氧化挂膜法-陶瓷平板膜联合除锰工艺和碱化法-陶瓷平板膜联合除锰工艺进行对比试验,通过试验得出的结论表明,由于陶瓷平板膜膜孔径与Mn2+尺寸相差1000倍,差距过大,且在中性条件下,Mn2+氧化速率比较缓慢,通过调节原水锰含量、膜通量及曝气量,在陶瓷平板膜表面均不能很好的形成锰质活性滤膜以达到除锰目的,提高pH使原水呈碱性,加快Mn2+氧化速率,对Mn2+有非常好的去除效果,可见碱化法-陶瓷平板膜联合除锰工艺是可行的。本文第二部分探讨了不同工艺参数和水质条件对碱化法-陶瓷平板膜联合锰工艺的影响,研究结果表明：氧化还原电位(ORP)是除锰的重要指标,氧化体(氧)和还原体(锰)的氧化还原电位差(△E)大于零反应即能进行,△E越大,反应速率越快,提高原水的pH可以有效降低Mn2+氧化还原电位,锰离子的氧化速度得以加快,提高处理效果,所以pH的变化对除高、低锰影响很大,pH越高,效果越好,但处理水的pH过高,需增设酸化装置,综合考虑最佳pH为7.70,其次,原水维持在最适pH的情况下,膜通量及溶解氧(DO)对除锰影响效果不明显,为满足处理效果、出水量及经济性考虑,最佳膜通量范围为225 ml/m2·min～300ml/m·min,溶解氧(DO)不低于2.3 mg/L即可。本文第三部分讨论了膜污染及膜的清洗再生,首先在上一阶段确定的最佳工况下连续进行除锰试验,结果表明,当跨膜压差0.1MPa时,膜通量急剧下降,通过电镜扫描发现膜被污染物覆盖,孔隙率降低,需要对陶瓷平板膜进行清洗,经分析可知污染物主要为MnO2并带有少量Mn(OH)2,均为碱性无机物,故本实验采用酸性化学清洗的方法。试验表明,0.1mol/LHCl浸泡膜片24h和0.1mol/LHNO3浸泡膜片24h清洗后的陶瓷平板膜,这两种清洗方案均可以完成膜的再生,恢复陶瓷平板膜除锰能力,是理想的清洗方式。综上所述,本文通过对陶瓷平板膜除锰方案的选择,最佳工况的确定,膜污染机理及膜清洗方法的研究,可知碱化法-陶瓷平板膜联合除锰工艺能有效处理含锰地下水,为进一步研究陶瓷平板膜除锰工艺奠定了基础。
[Abstract]:Groundwater as a drinking water source has the advantages of better water quality, less pollution, more safety, reliability and sanitation. The excess of iron and manganese in groundwater will cause a series of problems, such as health, economy and so on. The redox potential of manganese is higher than that of iron, so it is more difficult to oxidize mn 2 than Fe2. The hygienic standard of drinking water in our country requires manganese content to be below 0. 1 mg/L. In this paper, the application and treatment effect of ceramic flask plate membrane in groundwater manganese removal are discussed. In the first part of this paper, by means of dynamic filtration, the combined removal of manganese by aeration contact oxidation and ceramic plate membrane, and by air contact oxidation and ceramic plate membrane, is emphasized. The manganese removal process of high temperature catalytic oxidation combined with ceramic plate membrane and alkaline method combined with ceramic plate membrane were compared. The experimental results showed that the pore diameter of ceramic plate membrane was 1000 times different from that of Mn2. The gap is too large, and the oxidation rate of mn _ 2 is slow under neutral conditions. By adjusting the manganese content in raw water, membrane flux and aeration rate, the active manganese filter membrane can not be formed on the surface of ceramic flat membrane to achieve the purpose of manganese removal. Increasing pH can make raw water alkaline, accelerate Mn2 oxidation rate, and have a very good removal effect on Mn2. Therefore, it is feasible to combine alkaline process with ceramic plate membrane to remove manganese. In the second part of this paper, the effects of different technological parameters and water quality conditions on the alkaline process and ceramic plate membrane combined manganese process are discussed. The results show that the redox potential (ORP) is an important index for manganese removal. The redox potential difference (E) of oxidant (oxygen) and reducer (mn) can be obtained when the redox potential is greater than zero. The larger E, the faster the reaction rate, and the higher the pH of raw water, the lower the redox potential of Mn2. The oxidation rate of manganese ion can be accelerated and the treatment effect can be improved. Therefore, the change of pH has a great effect on the treatment of low manganese. The higher the pH is, the better the effect is. However, if the pH of the treated water is too high, it is necessary to add an acidizing device, considering the optimum pH of 7.70, and secondly, When the raw water was maintained at optimum pH, the effect of membrane flux and dissolved oxygen do on manganese removal was not obvious. In order to satisfy the treatment effect, the optimal membrane flux range was 225 ml/m2 min~300ml/m / min and the dissolved oxygen DOO was no less than 2.3 mg/L, in order to satisfy the treatment effect, the optimal membrane flux was 225 ml/m2 min~300ml/m / min and the dissolved oxygen DOO was no less than 2.3 mg/L. In the third part of this paper, the membrane fouling and membrane cleaning regeneration are discussed. Firstly, the manganese removal experiments are carried out continuously under the optimum conditions determined in the previous stage. The results show that the membrane flux decreases sharply when the transmembrane pressure difference is 0.1MPa. By scanning electron microscope, it was found that the membrane was covered by contaminants and the porosity was decreased, so it was necessary to clean the ceramic flat membrane. The main pollutants were MnO2 and a small amount of MnOHH ~ (2 +), all of which were alkaline inorganic substances, so the method of acid chemical cleaning was adopted in this experiment. The results show that the ceramic plate membrane washed by 0.1 mol / L HCl immersion for 24 h and 0.1mol/LHNO3 immersion in 24 h can regenerate the membrane and restore the manganese removal ability of the ceramic plate membrane, which is an ideal cleaning method. To sum up, through the selection of manganese removal scheme of ceramic flat membrane, the determination of optimum working condition, the study of membrane fouling mechanism and membrane cleaning method, it can be concluded that the alkaline method and ceramic plate membrane combined manganese removal process can effectively treat manganese containing groundwater. It lays a foundation for further study on manganese removal process of ceramic flat membrane.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.2

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