为研究寒旱区湿地包头南海子冰封期的污染物迁移特征,于2015年11月—2016年1月冰封期每月中旬在冰冻的湖面上破冰钻孔采集冰样和冰下水样,对样品的pH、溶解氧(DO)、总氮(TN)、总磷(TP)、硝态氮(NO3-N)、亚硝态氮(NO2-N)、氨氮(NH3-N)、溶解性磷(DP)、化学需氧量(CODCr)、叶绿素a(Chl(a))等指标进行检测,分析各项污染物指标在冰体和水体中的浓度特征及迁移规律,并对TN、TP、Chl(a)进行Pearson相关分析.结果表明,湿地水体在结冰过程中,污染物由冰体向水体迁移,迁移率Chl(a)〉TN〉CODCr〉TP;冰封期水体中各形态氮分布差异较大,而磷元素的赋存均以不溶性磷为主;通过分析湿地冰封期TN、TP、Chl(a)的相关性,得出三者在冰体中的相关性较水体显著;与非冰封期相比,冰封期水体中污染物的含量均高于非冰封期水体中的污染物含量,过长的冰封期使湿地有机污染趋势加重.
In order to investigate the contaminant migration of Baotou Nanhaizi wetland in cold and arid regions,samples of ice and the water under the ice were collected on the frozen lake by drilling the hole in the ice at middle of each month from November 2015 to January 2016. The samples were easted for pH,dissolved oxygen(DO),total nitrogen(TN),total phosphorus(TP),nitrate nitrogen(NO3-N),nitrite nitrogen(NO2-N),ammonia nitrogen(NH3-N),dissolved phosphorus(DP),chemical oxygen demand(CODCr),chlorophylla(Chl(a)),etc.,were analyzed. The concentration characteristics and migration pattern of every index in water and ice were analyzed.Pearson correlation analysis was also performed for TN,TP and Chl(a).The results showed that the contaminant in the lake migrated from ice to water while the water was freezing,the migration efficiency was Chl(a) 〉 TN 〉 CODCr〉 TP; the distribution of different forms of nitrogen changedobviously during the frozen period,but the occurrence of phosphorus was mainly the insoluble form.The correlation between TN,TP and Chl(a) in ice was more remarkable than in water,and the contents of the pollutants in the frozen water were higher than that in the non-ice period. The organic contamination of wetland would become more serious if the frozen period is too long.