水力负荷对3种滤料生物挂膜和溶解无机氮去除效果的初步研究

以人工模拟海水养殖废水为处理对象,探讨了PE(聚乙烯)环、珊瑚石和PP(聚丙烯)方便面净水板3种生物滤料对氨氮的吸附性能,获得了动态吸附的穿透曲线。研究了3种滤料的生物挂膜情况以及挂膜成熟后在不同水力负荷下的净水效果。结果表明,珊瑚石滤料的挂膜成熟时间明显短于PE和PP材质的滤料,生物膜厚度与水流流速呈负相关。水力负荷对3种滤料生物滤器的净水效果有显著影响,当水力负荷为19～51 m3/(m2.h)时,生物滤器对TAN、TOC和NO2--N有较为理想的去除效果。

Preliminary study on the biofilm cultivation and the dissolved inorganic nitrogen-removing efficiency with three filtering stuff under different hydraulic loadings

This paper is engaged in a study of biofilm cultivation and the dissolved inorganic nitrogen-removing efficiency with three kinds of filtering stuff under different hydraulic loadings.For the research purpose,we have done the total ammonia nitrogen dynamic adsorption experiments with three biological filter materials(PE,coralstone and PP) and compared the characteristic features of the three stuffings’ biofilm in treating the simulated mariculture sewage.Since the flow velocity and stuffings have direct effect on the purification of biofilter,it is necessary to experiment with the total ammonia nitrogen adsorption and biofilm cultivation under three hydraulic loadings.In doing so,we have to keep the temperature in a range of(22±1) ℃ and measure the necessary concentrations of a few pollutants,including the total ammonia,nitrite nitrogen,nitrate nitrogen and the total organic carbon.The experimental results we have gained have shown that the biofilm cultivation time of coralstone stuffing proves to be remarkably shorter than PE and PP.Once the biofilm becomes matured,it would be necessary to test and measure the biofilm thickness by the electron microscope and biofilm structure observed by the scanning electron microscope(SEM).The biofilm thickness and water flow velocity were also found negatively correlated.The result of SEM indicates that the biofilm mainly consists of bacillus and spirillum,whose activity should be tested in accordance with the removal rate under the five different hydraulic loadings of the simulated mariculture sewage so as to obtain the best hydraulic loading of each stuffing.Furthermore,once the ripe biofilm was formed,it would be possible for the biobilm of three stuffings in the corresponding biofilter to gain the best hydraulic loading to remove ammonia,nitrate nitrogen and the total organic carbon,respectively.As a result,BAF turned out to have fine removing effects on the total ammonia,nitrite nitrogen,and total organic carbon under the hydraulic loading of 19-51 m3/(m2·h).This paper can thus provide a theoretical basis and serves as valuable reference to choice of stuffings of fixed-bed biofilters in the mariculture recirculating aquarium system.