天然沸石覆盖层控制底泥氮磷释放的影响因素

通过实验室模拟,研究了天然沸石活性覆盖层控制底泥氮磷释放的影响因素,包括天然沸石粒径、温度、覆盖层厚度以及人工曝气等,结果表明:厌氧状态下富营养化水体的底泥会释放大量的氨氮和总磷,而天然沸石覆盖层可以有效地控制氨氮的释放,并且能降低总磷的释放速率;温度、沸石粒径、覆盖层厚度和曝气对天然沸石覆盖层控制底泥氨氮的短期释放基本没有影响,而沸石粒径和覆盖层厚度对覆盖层控制氨氮的长效性影响较大,且粒径越小或者厚度越厚,控制的时间越长;温度越高,覆盖层抑制底泥总磷释放的效果越差;沸石粒径越小或者覆盖层厚度越厚,控制底泥总磷释放的效果越好;对1cm厚粒径3～5mm沸石覆盖层表面进行曝气,有助于降低底泥总磷的释放速率;而对3cm厚粒径3～5mm的沸石覆盖层表面进行曝气,总磷的控制效果反而下降;对1cm厚粒径<2mm的沸石覆盖层表面进行曝气,初期对于底泥总磷释放的控制是不利的,而后期则可以降低底泥总磷的释放速率.

Influencing Factor of Natural Zeolite Barrier for Controlling Nitrogen and Phosphorus Release from Sediments

Influencing factor of natural zeolite barrier for controlling nitrogen and phosphorus release from sediments was researched. The results show that: (1) Zeolite barrier can effectively control the ammonia release from sediment under anaerobic conditions. (2) The ammonia release in a short term was not influenced by temperature, grain size of zeolite, thickness of barrier and aeration; However, long-term effectiveness of zeolite barrier was greatly influenced by grain size of zeolite and barrier thickness, and the little the grain size or the more thick the width, the better the effectiveness of controlling release of ammonia from sediment. (3) The release rate of total phosphorus from sediments increases as temperature heightening; the release rate of total phosphorus from sediments decreases with grain size of zeolite smaller or width thicker. (4) For barriers with zeolite's grain size 3-5 mm and width 1 cm, the rate of release of total phosphorus from sediments was decreased by aeration; For barriers with zeolite's grain size <2 mm and width 1 cm, efficiency of controlling release total phosphorus was decreased by aeration during prior period, and its efficiency was increased by aeration in the late stage; For barriers with zeolite's grain size 3-5 mm and width 3 cm, efficiency of controlling release total phosphorus was decreased by aeration.