【作者】 魏相君；

【导师】 李祖鹏； 韩志勇；

【作者基本信息】 兰州理工大学 ， 市政工程， 2012， 硕士

【摘要】 地下水中硝酸盐污染日益严重，已经成为突出的环境问题。本研究选择硝酸盐污染地下水为研究对象，利用麦秆和Fe~0（零价铁）组合材料的PRB反应器对硝酸盐降解的化学反硝化和生物反硝化过程进行研究，探索了Fe~0和小麦秸秆的组合材料PRB去除硝酸盐氮方法与机理，为控制地下水中硝酸盐的污染提供依据。本文通过静态实验研究以Fe~0为反应介质的化学反硝化效果和机理、小麦秸秆的水解碳源释放规律、及以小麦秸秆为碳源和载体的生物反硝化机理和效果，并通过铁/砂，铁/秸秆配比实验，和PRB动态模拟实验重点研究了Fe~0与小麦秸秆组合材料PRB反应器的最佳组合方式、修复效果和影响因素。静态试验结果表明，实验废水的pH值和Fe~0的粒径是影响硝酸盐去除效果的重要因素。由于Fe~0能较好的去除水中的DO,将其按1:9比例混合细沙，并前置于秸秆反应区，可以作为缺氧/厌氧生物反硝化前的除氧剂。小麦秸秆不但可以长期稳定的释放COD，为反硝化菌的生长提供足够的碳源，而且秸秆颗粒具有较大的比表面积，可以为微生物生长提供载体。介质配比实验表明Fe~0与小麦秸秆质量比为1：1时，实验综合效果较好。动态实验研究了铁砂比对反应器运行的影响和在最佳介质配比下的Fe~0与小麦秸秆组合材料PRB反应器反硝化效果与影响因素。结果表明，当铁/砂体积比3：7时，反应器在较长的时间内运行良好，且反硝化效果良好；室温下(23oC-32oC)在进水NO3--N浓度为90mg/L，流速为4cm/h时，硝酸盐氮去除率为92.79%。反应器启动快、耐冲击、受进水pH的影响小，能有效去除污水中的硝酸盐。对硝酸盐降解进行动力学分析，结果表明组合材料去除硝酸盐近似为准一级反应，反硝化速率较高，速率常数达到0.5h-1以上。虽然该反应器仍存在运行周期较短的缺点，但总体而言，反应组合材料价格低廉，反应器运行稳定，反应速率较快，具备良好的实用价值。更多还原

【Abstract】 Nitrate pollution in the groundwater increasingly serious, has become aprominent environmental problems. This paper provide degradation basis to controlthe pollution of nitrate in the groundwater,which choose nitrate pollution in thegroundwater for example, combined with the mechanism which remove nitratenitrogen by PRB technology studying the chemical denitrify and biological denitrifyof nitrate nitrogen and Combination material of Fe~0and wheat straw.This article introduce the chemical denitrify reaction effects and mechanismtaking Fe~0for media, the releasing hydrolysis carbon source rule of wheat straw, andthe biological denitrify mechanism and effect taking wheat straw as carbon source andcarrier through the static experiment. The optimal combination of materials, repairingeffect and influence way factors of PRB reactor focus on the Fe~0and wheat strawcombination of materials is researched through the iron/sand, iron/straw ratioexperiment, and the PRB dynamic simulation experiment.The results of static test show that pH value of the experimenting wastewater andparticle size ofFe0is the important factor about removing nitrate. The mixture ofFe0and sand at1:9in front of the straw reaction can be used as the deoxidizer beforeanaerobic organism is denitrified for Fe~0can remove DO in the water very well.Wheat straw can not only release COD stable in long time, provide enough carbonsources for the growth of denitrifying bacteria, but also can provide vehicle formicrobial growth with large specific surface area on straw particles. Medium ratioexperiments show that the comprehensive effect of the experiment is better when ratioof wheat straw and the mass is1:1.In the dynamic simulation experiments, considering the small particle size of ironpowder bond in PRB reactor, the iron and sand is mixed. The experimental resultsshow that, when the volume ratio of iron/sand is3:7, the reactor run well in a longtime, and the effect of denitrification is good. The denitrifying effect and theinfluencing factors of PRB reactor full ofFe0and wheat straw combination materialswith the best proportion of medium are tested in the dynamic experiment. The resultsshow that the removal efficiency of nitrate nitrogen is92.79%under roomtemperature (23-32) when velocity is4cm/h and water concentration is90mg/L.Because of fast startup, impact resistance, the small influence by water pH, reactorcan remove the sewage nitrate effectively. Through the dynamic analysis of nitratedegradation, the results show that combination material removal nitrate approximateshall prevail level1reaction; denitrifying rate is higher, above0.5h-1. Although the reactor operation cycle is still confronted with weakness of short period, reaction is ofa good practical value overall, for the price of combination materials is low, theoperation is stable, and the reaction rate is faster.更多还原