摘要
与传统脱氮工艺相比,同步硝化/反硝化(SND)工艺由于具有可降低能耗、减少基建费用等明显的优点,正受到越来越多的关注。在广泛查阅近期国内外相关研究成果的基础上,结合目前的工作,从同步硝化/反硝化现象发生的机理及工艺控制因素两个方面进行分析和阐述,并简要介绍了这一课题未来的研究方向。指出反应器溶氧不均、活性污泥絮凝颗粒中缺氧微环境的形成以及某些好氧反硝化菌和异养硝化菌的存在是同步硝化/反硝化现象的主要原因。同步硝化/反硝化的过程往往伴随着亚硝酸盐的积累现象,部分同步硝化/反硝化过程很可能是通过亚硝酸盐途径进行的。对于同步硝化/反硝化的工艺控制,目前主要通过控制碳源、活性污泥絮凝颗粒的大小、溶解氧、以及氧化还原电极电位(ORP)进行的。反应中可溶性COD(SCOD)的含量对于反硝化过程的进行具有重要的意义;碳源投加方式的改变,可改善同步硝化/反硝化的效果。絮凝颗粒的密度、尺寸与溶解氧的水平共同影响了絮体内部缺氧微环境的形成;同时在工艺过程中,控制溶解氧水平的变化可以取得较好的脱氮效果。对于氧化还原电极电位(ORP)控制的范围往往取决于污水的性质,同时也可结合其他一些指标(如pH、释放气体中NO浓度)作为综合的控制手段。
Simultaneous nitrification and denitrification (SND) has some obvious merits in comparison with traditional method for ammonium removal. This method could reduce energy consumption and construction cost. This paper discussed the mechanisms and control fac- tors of SND on the basis of consulting the recent domestic and international relevant research results. The trend of the study was also simply introduced. The uneven dissolved oxygen concentration in the reactor, the form of anoxic microzone in floc and the existing of some aerobic denitrifiers and some het-erotrophic nitrifiers are three major reasons of SND. In addition, this paper indicated that SND always accompanied with the nitrite accumulation and partial SND happened through nitrite possibly. At present process control methods of SND are including carbon source, activated sludge floc size, dissolved oxygen and oxidation-reduction potential (ORP). The concentration of soluble COD (SCOD) is important for the progress of SND, the change of throwing style of carbon source can improve the effect of SND. The density and size of activated sludge together with concentration of DO influence the forming of anoxic microzone in floc and the adjustment of dissolved oxygen level can obtain better result of ammonium removal. Control range of oxidation-reduction potential (ORP) depends on nature of sewage and it can become a comprehensive control means combining with some other parameters (such as pH, NO concentration in released gas).
出处
《上海环境科学》
CAS
CSSCI
CSCD
北大核心
2003年第12期878-882,共5页
Shanghai Environmental Sciences
基金
国家高科技研究发展计划(863项目)
编号2002AA601023
关键词
废水处理
工艺
同步硝化/反硝化
好氯反硝化
异养硝化
缺氧微环境
Simultaneous nitrification and denitrification Aerobic denitrification Heterotrophic nitrification Anoxic microzone
