摘要
为了探讨黑臭河道沉积物可转化态氮(TF-N)的赋存对上覆水的影响,以典型黑臭水体——南淝河为研究对象,采用连续提取的方法将沉积物中可转化态氮分为离子交换态氮(IEF-N)、弱酸浸提态氮(WAEF-N)、强碱浸提态氮(SAEFN)和强氧化剂浸提态氮(SOEF-N),研究南淝河沉积物中可转化态氮形态受排口类型和沉积物理化性质的影响规律,及其与上覆水氮素含量之间的关系。结果表明:南淝河沉积物可转化态氮以TF-NO-3-N为主,占TF-N的88.57%±6.13%,而TF-NH+4-N仅占TF-N的11.43%±6.13%;从赋存形态的角度看,南淝河沉积物中SOEF-N相对含量最高(57.48%±3.67%),WAEF-N次之(26.16%±3.10%),SAEF-N和IEF-N较少,其相对含量分别为10.30%±4.85%和6.05%±1.73%;沉积物中TF-NH+4-N含量受排口类型的影响较为敏感,且4种赋存形态氮含量受排口类型影响的规律各不相同。另外,pH值和有机质含量对IEF-N影响较大,而CEC影响着WAEF-N含量。上覆水中溶解有机氮(dissolved organic nitrogen,DON)含量与沉积物IEF-N含量之间的显著相关(P<0.05),表明沉积物中IEF-NH+4-N赋存含量越多,释放到上覆水体的可能性越大。研究结果表明黑臭水体是一个复杂的生态系统,调控沉积物可转化态氮形态给黑臭水体内源污染控制提供新思路。
To pursue the effects of transferable nitrogen in sediment on overlying water quality,nitrogen in sediment from Nanfei River,a typical malodorous-black water body,were fractioned into ion exchangeable form nitrogen（IEF-N）,weak acid extractable form nitrogen（WAEF-N）,strong alkaline extractable form nitrogen（SAEF-N） and strong oxidant extractable form nitrogen（SOEF-N） using sequential extraction method. Meanwhile,the impacts of different outfall and physicochemical properties on the forms of transferable nitrogen in sediment as well as the releasing risks of transferable nitrogen from sediment into overlying water body were discussed. It was found that TF-NO3^--N contributed 88. 57% ± 6. 13% to TF-N while only 11. 43% ± 6. 13% for TF-NH＋4-N/TF-N,which suggested that TF-NO3^--N was the dominant chemical form in sediment from Nanfei River. In addition,SOEF-N had the highest concentration（57. 48% ± 3. 67%） followed by WAEF-N（26. 16%± 3. 10%）,SAEF-N（10. 30% ± 4. 85%） and IEF-N（6. 05% ± 1. 73%） in sediment from Nanfei River. Significant influence of outfall types on（P〈0. 05） TF-NH＋4-N in sediment was detected,though the 4 kinds of TF-NH＋4-N forms displayed different variation trends in different outfall types. Moreover,IEF-N was greatly affected by pH and organic matters content while WAEF-N by CEC in sediment. There was significant correlation between DON concentration in overlying water and IEF-N contents in sediment（P〈0. 05）,indicating that higher IEFNH＋4-N content in sediment,the greater possibility for releasing into overlying water would arise. As a result,it can be figured out that the malodorous-black river was a complex ecosystem,and it was a novelty idea to transform the exchangeable nitrogen into stabile forms in sediment for the control of internal source pollution.
出处
《环境工程学报》
CAS
CSCD
北大核心
2017年第9期5057-5064,共8页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51608002)
安徽高校自然科学研究项目(KJ2016A096)
长江水环境教育部重点实验室开放课题(YRWEF201501)
关键词
南淝河
排口类型
氮赋存形态
上覆水
Nanfei River
outfall types
nitrogen forms
overlying water
