膨润土和硅藻土改性复配深度除磷的试验研究

发布时间：2018-06-17 07:33

  本文选题：改性膨润土 + 改性硅藻土　； 参考：《郑州大学》2015年硕士论文

【摘要】：水体中的磷是生物生长的必需元素,但磷的含量过高易引起水体富营养化,因此控制水体中磷的含量至关重要。利用矿物类粘土的特殊结构对磷进行吸附研究是一种新兴的处理技术,其具有除磷效果好、操作简单、运营成本低等特点,虽然我国的矿物类粘土资源丰富,但在实践工程方面还处于探索阶段,在深度处理方面的应用更少,故需要进一步的深入研究,为该方法在实际工程中的应用提供技术支持。本文分别研究了膨润土和硅藻土的改性条件及影响因素,利用扫描电镜(SEM)、X射线衍射分析(XRD)等技术手段表征了改性前后二者的微观结构和形态,并通过大量烧杯实验考察了其除磷效果。将二者复配后,用于模拟废水中磷的去除研究,投加到机械搅拌澄清池中对模拟二沉池出水进行深度处理,探索其最佳运行工况,为二沉池出水的深度处理及低浓度含磷废水的处理提供了一些参考。主要结论如下:1.膨润土原土的投加量为500mg/L时,除磷率为8%左右,除磷效果不理想;采用盐酸质量分数为5%,焙烧温度为400℃时,除磷效果较好。通过大量的静态烧杯试验,结果表明在改性膨润土的投加量为500mg/L、p H值为6~7、温度为25℃左右、混合反应时间为15min、沉淀时间为30min,此时改性膨润土的除磷率维持在50%左右。2.硅藻土原土的投加量为700mg/L时,除磷率为6%左右,除磷效果不理想;采用盐酸质量分数为10%,焙烧温度为400℃时,除磷效果较好。通过大量的静态烧杯试验,结果表明在改性硅藻土的投加量为700mg/L、p H值为6~7、温度为25℃左右、混合反应时间为15min、沉淀时间为30min,此时改性硅藻土的除磷率维持在48%左右。3.将改性后的膨润土和硅藻土按照一定的质量比例进行复配,通过大量静态烧杯试验,结果表明:在复配土的投加量为500mg/L,二者复配比例为60%:40%时,除磷效果较为理想,除磷率维持在76%左右。将复配后的改性土投加到机械搅拌澄清池中,深度处理并联多级A/O二沉池出水,试验结果表明:在投加量为500mg/L,机械搅拌转速为25r/min,停留时间为2h时为最佳工况,此时总磷的去除率达到82%,出水中总磷浓度低于0.5mg/L,达到了国家一级A类的污水排放标准。4.根据大量文献研究和市场调研,对复配土深度处理二沉池出水进行了技术经济分析,结果表明,复配土深度除磷具有高效、经济的特点,在理论和经济上是可行的。
[Abstract]:Phosphorus in water is an essential element for biological growth, but high phosphorus content can easily lead to eutrophication, so it is very important to control the phosphorus content in water. It is a new technology to study phosphorus adsorption by using the special structure of mineral clay. It has the characteristics of good phosphorus removal effect, simple operation and low operating cost, although the mineral clay resources are abundant in China. But the practical engineering is still in the exploration stage and the application in the advanced processing is even less, so it needs further research to provide technical support for the application of the method in the practical engineering. The modification conditions and influencing factors of bentonite and diatomite were studied in this paper. The microstructure and morphology of bentonite and diatomite before and after modification were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of phosphorus removal was investigated by a large number of beaker experiments. The mixture of the two is used to study the removal of phosphorus in simulated wastewater, and the effluent of the simulated secondary sedimentation tank is treated deeply by adding it to the mechanically stirred clarifier, and the optimal operating conditions are explored. Some references are provided for the advanced treatment of secondary sedimentation tank effluent and the treatment of low concentration phosphorous wastewater. The main conclusions are as follows: 1. When the dosage of raw bentonite is 500 mg / L, the phosphorus removal rate is about 8%, and the phosphorus removal effect is better when the mass fraction of hydrochloric acid is 5 and the calcination temperature is 400 鈩，

本文编号：2030247