天然沸石去除地下水中氨氮的研究

摘要

针对地下水中氨氮(NH-N)污染,采用天然沸石进行了试验研究,探讨了沸石种类、振荡强度、pH、吸附等温线等因素对去除地下水中氨氮的影响.结果表明,天然沸石对NH-N具有"快速吸附、缓慢平衡"的特点,浙江缙云沸石对地下水中NH-N具有较好的去除能力.当反应时间≤3 h,高振荡强度(200 r/min)的NH-N去除率大于低振荡强度(100 r/min)的;振荡强度显著影响NH-N的去除效果.当pH介于2.59～10.66时,去除率为74.23%～93.71%.中性初始pH(5.76～8.55)利于NH-N的吸附去除,酸性(pH≤2.59)导致去除率略有下降,而碱性(pH≥10.66)致使去除率急剧下降.缙云沸石的Langmiur吸附等温公式为:Q=0.964 8μ/(1+0.181 0μ),而Freundlich吸附公式为:Q=0.815 8μ0.576 2,椎荐采用后者.%An experiment was carried out by using natural zeolites to deal with the NH4-N contamination in groundwater. The effects of zeolite type, vibration intensity ,pH and adsorption isotherm curve on the removal effect of NH4-N were investigated. As indicated by the experimental results,NH4-N adsorption by natural zeolites was characterized by “fast adsorption and slow equilibration” ,and the zeolites in Jinyun of Zhejiang Province showed the excellent performance for NH4-N removal. The removal efficiency at high vibration intensity (200 r/min) was greater than that of low intensity ( 100 r/min) at reaction time ≤3 h ,NH4-N removal efficiency was significantly influenced by the vibration intensity. The removal efficiency ranged from 74.23 ％ to 93.71％ at the pH of 2.59 - 10.66. The neutral pH (5.76 - 8.55 ) could promote NH4-N adsorption removal; the acidic pH value (pH≤2.59) caused a slight decrease in removal efficiency; however,the alk pH value (pH≥l0.66) led to a sharp decrease in the removal efficiency. Langmiur adsorption isotherm curve of Jinyun zeolite was Q =0.964 8 μ/( 1 +0. 181 0 μ) ,and its Freundlich adsorption isotherm curve was Q =0.815 8 μ0.5762. The latter is recommended.