上海市郊河流底泥氮磷释放规律的初步研究

上海市郊河流底泥有很高的氮、磷负荷。为了研究底泥氮、磷释放规律，取一定量的新鲜底泥在室内进行通气和厌气培养试验；同时，用鱼塘底泥作对照。结果表明：（1）厌气条件下，底泥NH3－N释放速率和释放量高于通气条件，培养液NH3－N可在较长时间内维持峰值水平；通气条件下，由于硝化作用较强，培养液NH3－N含量达到峰值后，迅速下降。（2）厌气条件下，底泥水溶态磷的释出量远远高于通气条件。厌气条件下释放的正磷酸盐大部分源自Fe-P的还原解吸。（3）鱼塘底泥氮、磷释放量高于河流底泥，但其氮、磷负荷却非最高，这与其含有大量的易降解性有机质有关。

Preliminary Study on Nitrogen and Phosphorus Release from the Creek Sediments, Outskirts of Shanghai

High loads of nitrogen and phosphorus were found in the sediments of the creeks, of suburb, Shanghai. A laboratory study has been conducted to observe the release of nitrogen and phosphorus from the sediments under both anaerobic and aerobic conditions. The sediment from a fish pond was also used as an experimental material. The results were as follows: 1) anaerobic ammonia release from the sediments was greater and quicker than the aerobic release. Furthermore, high level of ammonia concentrations in anaerobic waters were maintained; in aerobic waters, however, ammonia concentrations decreased sharply after reaching the peaks because of strong nitrification, 2) anaerobic phosphorus release was greater than aerobic and the released ortho-phosphate was mainly from Fe-bound phosphorus, 3) potential of nitrogen and phosphorus release from the sediments of dredged creeks was relatively weak, 4) ammonia and phosphorus release from fish pond sediment was greater than that from creek sediments, though its K-nitrogen and total phosphorus were not the highest. High content of easily degraded organic matter in fish pond sediment was responsible for this.