DEVELOPMENT OF SIMPLE TREATMENT SYSTEM FOR A LARGE QUANTITY OF NITRATE-POLLUTED WASTEWATER

本研究的目的是建立一种利用自养型硫杆菌的脱氮系统，以处理C/N比很低的废水。在柱中使用硫颗粒作为电子供体。得到以下结果。1）亚硝酸盐的抑制作用已知亚硝酸盐作为反硝化反应的中间产物形成，对反硝化本身产生抑制作用。通过各种条件下的实验，用与酶反应动力学中的非竞争性抑制模型相同的动力学模型解释了抑制行为。抑制常数随pH值的降低而降低（抑制效果增加），表明未溶解的硝酸可能是抑制的来源。对亚硝酸盐还原的抑制程度低于对硝酸盐还原的抑制程度。悬浮体系中影响还原速率的最低硝酸浓度低于生物膜体系。这 ...更多信息 2）炼铁厂酸洗废水的连续处理通过对石灰石和硫磺颗粒填料塔的长期运行，发现废水中ppm级的重金属或氟化物的影响可以忽略不计。在相同硝酸盐浓度的模拟废水中，反硝化效果基本不变，而在工业废水中，反硝化效果随运行时间的延长而逐渐下降。这被怀疑是由实际废水中碱度的降低引起的。通过对石灰石颗粒的分析，发现铁、磷酸盐和硫的化合物在表面有存款，这可能会导致碱度供应的降低。3）垃圾填埋场废水的连续处理采用石灰石和硫颗粒填充柱连续处理垃圾填埋场废水中的硝酸盐。获得恒定的性能可能是因为硝酸盐和有机碳的浓度都低。废水中的有机碳化合物的成分不明确，但没有观察到实质性的抑制作用。少

The aim of this study was to establish the nitrogen removal system employing autotrophic thiobacillus denitrificans for wastewater of which C/N ratio was very low. Sulfur particle was used as an electron donor in a column. The following results were obtained.1)Inhibition by nitrite Nitrite, formed as an intermediate of denitrification reaction, is known to cause an inhibitory effect on denitrification itself. By the experiments under various conditions, the inhibition behavior was explained by the same kinetic model as a non-competitive inhibition model used in enzymatic reaction kinetics. An inhibition constant lowered(inhibition effect increased) with the decrease in pH, indicating that undissolved nitric acid might be the source of inhibition. The degree of inhibition against nitrite reduction was lower than that for nitrate reduction. The minimum nitric acid concentration that showed the influence on reduction rate in suspension system was lower than that in biofilm system. This in … More dicated the importance of pH control during operation.2)Continuous treatment of wastewater from acid-washing process of iron works The effect of heavy metals or fluoride involved in wastewater of ppm order was found to be negligible based on long-term runs with a column packed with limestone and sulfur particles. The performance of denitrification dropped gradually during operation in industrial wastewater, whereas it was almost constant in model wastewater of same nitrate concentration. This was suspected to be caused by the decrease of alkalinity in actual wastewater. By the analysis of limestone particles, iron, phosphate and sulfur compounds were observed to deposit on surface, which might cause the reduction of alkalinity supply3)Continuous treatment of the wastewater eluted from the landfill Nitrate involved in the wastewater from land fill was treated continuously employing a column packed with limestone and sulfur particles. A constant performance was obtained probably because the concentrations of both nitrate and organic carbon were low. The components of organic carbon compounds in wastewater were not clarified, but substantial inhibitory effect was not observed. Less