3种覆盖材料对底泥磷释放的抑制及影响因素研究

Inhibiting effect of the three kinds of barriers on the release of sediment phosphorus and the influential factors

采用试验的方法研究了建筑废料、天然沸石和自制陶粒对底泥磷释放的抑制作用。结果表明，在覆盖厚度为2 cm、温度为18-22℃的条件下，自制陶粒的抑制效果最好，天然沸石次之，建筑废料最差。天然沸石覆盖底泥后，在18-25℃范围内，温度越高，覆盖法抑制磷释放的效果越差。在第57 d，温度为25℃时，上覆水中总磷质量浓度为1.598 mg/L，而在室内水温（18-22℃）条件下，上覆水中总磷质量浓度为0.984 mg/L。覆盖层厚度越大，沸石粒径越小，控制底泥磷释放的效果越好。在温度为室温、粒径为3-5 mm的条件下，在第57 d，覆盖厚度为3 cm时，上覆水中总磷质量浓度为0.565 mg/L，而覆盖厚度为1 cm时，上覆水中总磷质量浓度为0.984 mg/L；粒径由3-5 mm减小到20-40目（0.42-0.83 mm），第32 d的上覆水中总磷质量浓度由2.80 mg/L降低到2.06 mg/L，第57 d的上覆水中总磷质量浓度由3.59 mg/L降低到2.64 mg/L。

This paper is aimed at presenting our analysis on the inhibiting effects of the three kinds of barriers on the release of sediment phosphorus and the influential factors. The three kinds of barring materials are known as construction waste, natural zeolite and homemade ceramisite. In this paper, we have made laboratory experiments and analysis of their inhibiting function and gained positive results, which can be stated here literally. That is, when the temperature got to 18-22℃ and the thickness of the barriers turned to be 2 cm, the inhibiting effect of the homemade ceramisite tends to be optimal, which is followed by the natural zeolite, and then by the construction waste. For the actual inhibiting function of natural zeolite, it can be said that, the higher the temperature, the greater the function of sediment phosphate release, and, in turn, the worse the control effect. For example, on the 57 th day, when the temperature got to 25℃, the total phosphorus concentration tends to arrive at 1.598 mg/L, which was likely to lead the overlying water in the indoor temperature （18-22℃） with the total phosphorus in the overlying water getting to 0.984 mg/L. However, if the thickness of the barrier was made thicker and the zeolite grain size was made finer, it would be possible to increase the physical blocking effect and in turn to increase the control effect. The experimental results of our 57 days＇ testing reveal that, suppose the grain size was the same, say 3-5 mm in the room temperature （18-22℃）. When the barrier thickness was 3 cm, the concentration of the total phosphorus in the overlying water would be 0.565 mg/L. In contrast, when the thickness was 1 cm, the concentration of total phosphorus in overlying water would be 0.984 mg/L. However, when the grain size tends to decrease by 3-5 mm to 0.42-0.83 mm, the total phosphorus concentration of overlying water would be falling from2.80 mg/L to 2.06 mg/L, on the 32^ nd day, and later, the total phosphorus concentration of overlying water would be falling from3.59 mg/L to 2.64 mg/L by the end of the 57 ^th day.