Yu Hong-Lei, Huo Shou-Liang, Yang Zhou-Sheng, Xi Bei-Dou, Zan Feng-Yu, Zhang Jing-Tian
College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241000, China.
Huan Jing Ke Xue. 2013 Jun;34(6):2256-62.
In this study, we present a nanofiltration (NF90, NF270) pretreatment to increase the precision of dissolved organic nitrogen (DON) measurements in water samples. The variations of DON measurements with and without NF pretreatment were investigated. And the effects on the removal of dissolved inorganic nitrogen (DIN) by NF90 and NF270 were compared. As shown in the results, the average removal rates reached 30.7%, 55.9% of NH4(+)-N, 50.0%, 73.1% of NO3(-) -N and 42.9%, 72.0% of NO2(-)-N for NF90 and NF270 pretreatment, respectively. NF270 was obviously more effective to remove the DIN species. Concentrations of DON measured using traditional methods varied from 0.09 to 0.46 mg x L(-1), with negative concentration (-0.08 mg x L(-1)) at site 2 and the DIN/TDN ratio ranged from 85.3% to 105%; while the concentrations of DON measurements varied from 0.03 to 0.58 mg x L(-1), and the DIN/TDN ratio ranged from 76.1% to 90.6% for NF90 pretreatment and varied from 0.10 to 0.59 mg x L(-1), and the DIN/TDN ratio ranged from 47.5% to 84.5% for NF270 pretreatment. The results indicated that nanofiltration pretreatment could effectively remove the DIN species, decrease the standard deviation of DON measurements and increase the precision of DON measurements. The distribution of DON in water samples of Beijing Olympic Forest Park was investigated. The results showed that there was seasonal variation in the concentrations of DON in landscape water from the Olympic Forest Park. And there was significant difference between the north and south part. The DON concentrations were less than 0.2 mg x L(-1) in November, March and May and higher in July in the north part, while the DON concentrations were lower in May and higher in November and March in the south part, ranging from 0.40-0.65 mg x L(-1).
在本研究中，我们提出了一种纳滤（NF90、NF270）预处理方法，以提高水样中溶解有机氮（DON）测量的精度。研究了有无NF预处理时DON测量值的变化情况。并比较了NF90和NF270对溶解无机氮（DIN）的去除效果。结果表明，NF90和NF270预处理时，NH4(+)-N的平均去除率分别达到30.7%、55.9%，NO3(-)-N的平均去除率分别达到50.0%、73.1%，NO2(-)-N的平均去除率分别达到42.9%、72.0%。NF270对去除DIN种类显然更有效。采用传统方法测得的DON浓度在0.09至0.46 mg·L(-1)之间，在2号点位出现负浓度（-0.08 mg·L(-1)），DIN/TDN比值在85.3%至105%之间；而NF90预处理时DON测量浓度在0.03至0.58 mg·L(-1)之间，DIN/TDN比值在76.1%至90.6%之间；NF270预处理时DON测量浓度在0.10至0.59 mg·L(-1)之间，DIN/TDN比值在47.5%至84.5%之间。结果表明，纳滤预处理能有效去除DIN种类，降低DON测量的标准偏差，提高DON测量的精度。对北京奥林匹克森林公园水样中DON的分布情况进行了研究。结果表明，奥林匹克森林公园景观水中DON浓度存在季节变化，且南北部存在显著差异。北部11月、3月和5月DON浓度低于0.2 mg·L(-1)，7月较高；而南部5月DON浓度较低，11月和3月较高，范围在0.40 - 0.65 mg·L(-1)之间。
