复合垂直流人工湿地对海水养殖外排水脱氮效率的研究

Research on Nitrogen Removal Rate of Marine Aquaculture Wastewater by the Integrated Vertical-Flow Constructed Wetlands

为了提高复合垂直流芦苇人工湿地系统的脱氮效率,并将其运用于高效处理海水养殖外排水,构建了复合垂直流人工湿地对海水养殖外排水脱氮效率的研究实验。养殖外排水选择海水养殖大菱鲆外排水;水生植物选择芦苇,种植密度为64株/m2;湿地系统基质填料选择珊瑚石、蛭石和细砂。在系统未循环的情况下稳定运行一段时间,探究不同基质层与系统氮效率的关系。在系统循环条件下,探究添加硝化细菌和调节间歇进水方式对系统脱氮效果的影响。实验结果表明,添加硝化细菌可以提高系统对DIN的去除率,且可以在短时间内迅速提高系统对NH_4^+-N去除率,添加硝化细菌可以作为提高系统对DIN的去除率和短时间内提高系统对NH_4^+-N去除效率的一种调控手段;选择不同的间歇进水方式表明,间歇进水可以提高系统对NO_3^--N和DIN的去除率,且连续进水、间歇6 h、间歇12 h进水时,系统对NH_4^+-N的去除率较其它调节方式高,综合考虑系统运行的合理性和高效脱氮性,间歇进水12 h较为合理,调节间歇进水时间可以作为调控系统脱氮效率的一种手段。

In order to improve nitrogen removal efficiency of the integrated vertical-flow reed constructed wetland system and to treat the marine aquaculture wastewater efficiently, experimental study on the regulation of nitrogen removal of marine aquaculture wastewater by the integrated vertical-flow constructed wetlands was constructed. The psetta maxima aquaculture wastewater was selected as the marine aquaculture wastewater. The reed was chosen as the aquatic plants, and the density was 64 plants per square meter. The coral rock, vermiculite and fine sand were chosen as the substrate of the system. The system was operated for a period of time under the condition of the system without circulation firstly to explore the relationship between different substrate layer and system efficiency of nitrogen. The effects of nitrifying bacteria and intermittent water way on the nitrogen removal rate were researched under the condition of the system with circulation. The results demonstrated that, adding nitrifying bacteria could improve the removal rate of DIN of the system, and the removal rate of NH4＋-N improved quickly of the system. Choosing the different way of intermittent water showed that, adjusted the intermittent water way could improve the removal rate of DIN and NO3-N of the system, and the removal rates of the NH4＋-N were higher under the intermittent water for 0 h, 6 h, 12 h than 24 h. Considering the rationality and high efficiency of nitrogen removal rate on the system, the optimal condition was intermittent 12 h, and adjust time of intermittent water could be used as a control measure to improve the nitrogen removal rate efficiently.