桂林市区湖泊沉积物的氮磷研究

对桂林市区湖泊木龙湖、西清湖、宝贤桥、观漪桥、榕溪桥样点湖底表层0～5 cm沉积物进行了采样调查,并分析其总氮、氨氮、亚硝酸盐氮、有机磷、无机磷、有机质、无机质的含量,结果表明,总氮的平均浓度为3 363.6 mg/kg,其中氨氮是沉积物中氮的主要存在形式,占TN的82%。桂林市区湖泊沉积物中磷的含量为230.46～291.35 mg/kg,其中无机磷占主要成分,平均占TP的78.7%。造成这种差异的主要原因为桂林市区没有大型的有机污染源纳入,只有小部分植物残体随着地表径流汇入湖体,同时有机磷和有机氮在不断地被矿化为无机磷、无机氮。部分凹岸带已出现的富营养化现象可能与湖泊沉积物N、P不断积累并释放到水体中有关。

Study on Nitrogen and Phosphorus in Lake Sediments in Guilin City

The sampling investigation on sediments in 0-5 cm surface layers in the bottom of the lake was conducted in Mulong Lake,Xiqing Lake,Bridge of Baoxian,Bridge of Guanyi and Bridge of Rongxi in Guilin City,and total nitrogen,ammonia nitrogen,nitrite nitrogen,organic phosphorus,inorganic phosphorus,organic matter,inorganic qualitative contents were analyzed.The experimental results showed that the average concentration of total nitrogen is 3 363.6 mg/kg,of which ammonia nitrogen is the major existence form in sediments,accounting for 82% of the TN.The contents of phosphorus in Guilin urban lakes sediment is 230.46-291.35 mg/kg,inorganic phosphorus accounts the main ingredients,average accounts for 78.7% of the TP.The main reason for causing this difference is that Guilin City has no big organic pollution bring into,only a small fraction plant residue with surface runoff into lake.At the same time organophosphate and organic nitrogen in constant are ored into inorganic nitrogen,inorganic phosphate.The phenomenon of the eutrophication in the section of the concave bank in Sihu may be related to the continuous accumulation of N,P in lake sediments and release to the water.