【摘要】 为了探讨干湿条件对沟渠沉积物净化氮能力的影响,通过模拟试验研究了不同干涸再水淹条件对沟渠沉积物净化水体氮能力的影响。结果表明,初始浓度约为4.5mg/L,随着干涸时间的增加,沟渠沉积物对NH4+-N的净化效率提高;水中NO3--N均呈先增加后减少趋势;连续水淹(CW)、干涸4d再水淹(DFW)及干涸8d再水淹(DEW)条件下,总氮去除率分别为84.5%,90.2%,93.3%。经干涸处理的沟渠沉积物对NH4+-N的去除效率明显高于连续水淹方式下的去除效率,也促进了反硝化作用的进行;当水中总氮浓度不高于10mg/L时,沟渠短期干涸(8d)再水淹,有利于沉积物对氮的去除。试验初期水中氮素减少主要是由于沉积物的吸附作用和微生物的利用。因此,在降雨季节三江平原干湿变化有利于沟渠沉积物对氮的去除。更多还原

【Abstract】 In order to discuss the effects of drying and wetting conditions on the capability of ditch sediments purifying nitrogen,different drying and wetting conditions of the simulation tests were performed to study the purification capacity of sediments.The results showed that the purification efficiency of ditch sediments was improved with drying time increasing.At the same time,the concentration of nitrate reached to the peak and then decreased.Finally,the removal rate of total nitrogen under conditions of continuous wetting(CW),drying for four days and then wetting(DFW) and drying for eight days and then wetting(DEW) was 84.5%,90.2% and 93.3%,respectively.Dried ditch sediments may increase the removal efficiency of ammonia nitrogen in water,and promote the ability of denitrification.While the concentration of total nitrogen was close to 10 mg/L,it was useful for the nitrogen removal to dry ditch sediments for eight days.Adsorption of sediments and microbial absorption were the main reasons of total nitrogen reducing in the first few days.Therefore,the change of the drying and wetting conditions during the rainfall season in Sanjiang plain was useful for the nitrogen removal.更多还原