College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu 24100, China.
Int J Environ Res Public Health. 2019 Mar 14;16(6):929. doi: 10.3390/ijerph16060929.
KCl-extractable sediment dissolved organic nitrogen (KS-DON) extracted from sediments near drinking water intakes of six drinking water sources in Taihu Lake in China was partitioned into hydrophobic and hydrophilic fractions and high/low molecular weight fractions. The results showed that the total dissolved nitrogen (TDN) contents of the extracts ranged from 67.78 to 128.27 mg/kg. KS-DON was the main TDN species, accounting for more than 50%, with NH₄⁺-N and NO₃-N averaging 30% and 20%, respectively. The molecular weight fractions of <1 kDa accounted for almost half of KS-DON. Hydrophilic compounds accounted for more than 75% of KS-DON. Three fluorescence peaks were identified: soluble microbial byproducts (A); protein-like substances (B); and humic acid-like substances (C). It is concluded that the KS-DON in Taihu Lake sources has higher bioavailability and higher risk of endogenous release. Ecological dredging and establishment of constructed wetlands are possible measures to reduce the release of endogenous nitrogen.
从中国太湖 6 个饮用水水源地取水口附近沉积物中提取的 KCl 可提取溶解有机氮（KS-DON），被分为疏水性和亲水性以及高分子量和低分子量部分。结果表明，提取物中的总溶解氮（TDN）含量在 67.78 到 128.27 毫克/千克之间。KS-DON 是 TDN 的主要成分，占比超过 50%，NH₄⁺-N 和 NO₃-N 分别平均占比 30%和 20%。<1 kDa 的分子量部分占 KS-DON 的近一半。亲水性化合物占 KS-DON 的比例超过 75%。鉴定出三个荧光峰：可溶微生物副产物（A）；蛋白质样物质（B）；和腐殖酸样物质（C）。综上所述，太湖水源中的 KS-DON 具有更高的生物利用度和更高的内源释放风险。生态疏浚和人工湿地的建立可能是减少内源氮释放的措施。
