| As an important part of water resources, groundwater has become an important source of drinking water in many cities of our country because of its strong storage capacity and stable water supply conditions. There are 1817 groundwater drinking water sources in our country, accounting for about 38% of urban drinking water sources. However, groundwater quality has been condidered to getting worse because of geological factors and human activities. Iron and manganese are the main indicators of groundwater. Groundwater with high content of iron and manganese brings a lot bad influences on human lives, industry and agrriculture production. Therefore, there are more and more researchers focus on developing the simple and effective techonology of iron and manganese removal process.The common methods of removing iron and manganese in groudwater are oxygenization (natural oxidation, contact oxidation, chemical oxidation and biological oxidation method), ion exchange, activated carbon absorption method, etc. Among the methods, absorption has been considered as one of the most popular way because of its variety of absorbing meterials, wide range of application, user-friendly control and evironmental friendly. Therefore, finding economically, efficiently and highly applicable absorbing meterials is the key to the application of adsorption method.In this paper, we firstly use the activated carbon, cornstalk, zoelite, attapulgite as carrier of FeOOH to make composite absorbent. Comparing the results of removals before and after carrying, We found that zoelite/FeOOH is the most effective absorbent. By adjusting the molar ratio of OH- to Fe3+(alkali ratio), we found that zeolite/FeOOH in 4:1 propotion behaves better than the others. Meanwhile, we made characteriztion for it by scanning electron microscope (SEM), X-ray diffraction (XRD) and specificsurface area determination. Then we analized the influence factors of iron and manganese removal abillity by static absorption experiment, found out the best condition for absoption. We also did research on absorption isotherm and kinetics which are based on the results above. The results of this paper are as follows:1. Scanning electron microscope (SEM), X-ray diffraction and specificsurface area determination are used to characterize the properties of the zeolite and zeolite/FeOOH. We found that zeolite loaded FeOOH might have new crystal generation, the layered str-ucture of compound is more obvious, and the contact area is increased which is con-ducive to the removal of pollutants.2. The dosage of adsorbent is 0.3g, pH is 7.5, and adsorption time is 4h, the re-moval rate of Fe2+ and Mn2+ are 100% and 99.49%, respectively. The remaining Fe2+ Mn2+ concentration can meet the requirements of current national standards for drink water. The dosage of adsorbent, dsorption time, pH value effect on the removal of iron and manganese by the zeolite/FeOOH gradually decreased.3. Through the study of adsorption isotherms of zeolite/FeOOH adsorption of Fe2+ and Mn2+, found that the Langmuir equation can better fit the process of zeolite/FeOOH on Fe2+ and Mn2+. The maximum adsorption saturation of Fe2+ and Mn2+ are 8.18mg/g and 2.69mg/g, respectively.4. The adsorption process of Fe2+ and Mn2+ by the zeolite/FeOOH are described by the pseudo second-order kinetic model. |
PDF Full Text Request