好氧条件下零价铁对地下水中硝酸盐氮的去除研究

Removal of Nitrate in the Groundwater by Fe^0 in the Aerobic Condition

在好氧条件下,将Fe0用于模拟地下水中NO-3的去除,考察了投加量、温度、pH值和共存阴离子对去除效果的影响,并对反应过程进行了动力学分析。结果表明,好氧条件下,Fe0的投加量越大,硝酸盐的去除速率越高,效果越好;与碱性条件(pH=11)相比,酸性条件(pH=2)更利于硝酸盐的去除,反应4h后去除效果达97.77%;升高温度能促进反应的进行,增加铁粉的投加量会提高硝酸盐的去除效率;水体中的共存阴离子与硝酸盐产生竞争作用,对去除率负影响大小顺序为SO2-4>HCO-3>Cl-,而Cl-的引入能产生新的絮凝沉淀,增强对硝酸盐的去除效果。动力学分析表明,该反应过程符合Langmuir-Hinshelwood模型,属于一级动力学。

In aerobie condition, Fe° is applied into the removal of NO; in the groundwater. The influences of dosage, temper ature,pH value and coexisting anions on the removal are investigated and also the reaction process is analyzed by dynamics. The results show that the removal is higher with the increase of dosage of Fe° ; the removal was also higher in the acid cendi tion （ pH = 2 ） than alkaline condition（ pH = 11） and the removal can reach 97.77 % after 4 hours; the increase d tempera ture can promote the reaction and with the increase of Fe powder, the removal rate of nitrate can be increased; the coexist aniom acts competitively with nitrate, affect/rig the removal following this order SO^24- 〉 HCO3- 〉 CI- and the introduction of C1 can produce a new floeculafion which improves the removal efficiency. The dynamics indicates that this process confirms to Langmulr- Hinshelwoed and first- order kinetic model.