Studies on the Water Purification in the Coastal Areas of Inner Bay Using Nitrifying and Denitrifying Bacteria in the Tidal Bottom-Mud

本研究的目的是阐明潮滩底泥中硝化细菌和反硝化细菌的生物活性与各种环境因子之间的关系，并利用这些细菌代谢维持的硝化和反硝化过程来净化内湾沿岸水域。（1）从有明海潮滩底泥中筛选出一株生物活性较高的硝化细菌和两株生物活性较高的反硝化细菌。此外，这些细菌的性质进行了澄清。（2）阐明了底质浓度、温度、pH值、还原电位等控制因素与底泥硝化反硝化速率的关系。硝化和反硝化速率与基质浓度和温度的关系可用Mechaelis-Menten方程描述.该方程表明了硝化和反硝化速率的最佳温度和这些Timit值。(3)A利用潮汐底泥去除废水中无机氮化合物的方法。提出了许多生物活性高的硝化细菌和反硝化细菌的生活环境。此外，还根据这种方法制作了一个用于去除它的试验装置。（4）通过试验掌握了NH_4^+浓度、温度、流量、含泥量、pH值、硝化菌数和反硝化菌数与脱氮率的关系。（5）验证了该去除装置的实用性，并确认了有明海潮底泥的水质净化能力。另一方面，也发现了移除装置在实际使用中存在的问题。

The purposes of the present research are to clarify the relationships between the biological activity of nitrifying and denitrifying bacteria and various environmental factors in the tidal bottom-mud, and to use the nitrification and denitrification processes maintained by the metabolism of these bacteria in order to purify water of the coastal areas in the inner bay. The conclusions obtained by the present research during three years from 2001 to 2002 are summari zed as follows :(1)A kind of nitrifying bacteria and two kinds of denitrifying bacteria with high biological activity were selected and isolated from the tidal bottom -mud i n the Ariake Sea. Moreover, the properties of these bacteria were clarified.(2)The relationships between the nitrification and denitrification rates in the tidal bottom -mud and control factors such as substrate concentr ation, temperature, pH, reduction potential were clarified. A Mechaelis -Menten equation was valid for the relation between nitrification and denitrification rates, substrate concentration and temperature. This equation indicated the optimum temperature for nitrification and denitrification rates and these Timit values.(3)A method for removal of inorganic nitrogen compounds i n the waste water using the tidal bottom-mud. where many nitrifying and denitrifing bacteria with high biological activity lived was proposed. Moreover, a trial device for its removal based on this method was made.(4)The relationships between N-removal rates of this trial device and NH_4^+ concentration, temperature, flow, mud-content, pH and number of nitrifying and denitrifying bacteria were commanded experimentally.(5)The utility of the removal device was verified and the extent power of water purification of the tidal bottom -mud in the Ariake Sea was confirmed. On the other hand, the issues for the practical use of the removal device were also found.