给水排水 评职论文下载 摘要:考察了采用SBR法处理氨氮浓度较高的给水排水 评职论文下载化工废水时供氧方式对硝化过程中DO、ORP和pH值变化规律的给水排水 评职论文下载影响。试验结果表明,在曝气量恒定的条件下,可以硝化过程中DO和pH值升高速率的不同表征反应的进行程度,即当氨氮浓度接近零时,DO和pH值升高速率或变化幅度加大,二者可以作为SBR硝化反应时间的控制参数,而ORP值对SBR硝化反应结束的指示作用不是很明显;在DO量恒定的情况下,pH值在整个硝化反应过程中都是缓慢下降或趋于稳定的,当硝化反应结束时突然升高,因此pH值也可作为SBR硝化反应时间较好的控制参数,而ORP值在硝化反应的初期快速升高,之后升高的速度越来越慢直至趋于平稳,它对SBR硝化反应结束的指示作用同样不是很明显。 关键词:SBR法 DO ORP pH值 硝化反应
中图分类号:X703.1 文献标识码:A 文章编号:1000-4602(2002)10-0001-05
Study on Short-cut Nitrification by Using SBR Process and Its Process Control WANG Shuying1, ZENG Wei1, DONG Wenyi2, DU Hong2, CHEN Tao2
( 1.School of Environment and Energy Engineering,Beijing Polytechnic Univers ity,Be ijing 100022,China;2.School of Municipal and Environmental Engineering, Harbin Institute of Technology,Harbin 150090,China)
Abstract:In the use of SBR process for treatment of chemical wastewater with high NH3-N concentration,investigation was made for the effect of oxygen supply on DO,ORP and pH variation in nitrification process.The result showed that under the fixed aeration rate,different rising rate of DO and pH may be used to express the progress of nitrification, that is,when NH3-N concentration approaches zero,the increase occurs in the rising rate and variation range of DO and pH,the both can be used as parameters for controlling nitrification time,and ORP gives no obvious indication of the ending of nitrification.Under the fixedDO,pH drops slowly or tends to be stable in whole course of nitrification,and abruptly rises in the ending of nitrification.Therefore,pH is also a desired controlling parameter in SBR nitrification;while ORP rises rapidly in the initial stage of nitrification,and then it rises at slower and slower speed until it approaches to stability,it also does not indicate distinctly the finishing of SBR nitrification. Keywords:SBR process; DO; ORP; pH value; nitrification
SBR法的自动控制问题一直是人们研究和关注的热点[1~3],因为只有将SBR法的自控提高到更高的层次,使系统的运行更为稳定可靠,才能充分发挥SBR的优势,而寻找一些既可以简单地在线检测,又可以指示反应进程的控制参数是解决SBR自动控制问题的关键。研究表明,活性污泥法中DO、ORP和pH值的变化规律能从不同角度、不同程度反映有机物降解及脱氮除磷生化反应的进程,因此以它们作为控制参数是可行的[4~6]。SBR脱氮系统的大部分反应过程处于好氧状态,而曝气量的大小和曝气时间的长短对于保证出水水质和节省能耗至关重要,为此研究了在不同供氧方式下(曝气量恒定和DO量恒定)DO、ORP和pH值在好氧过程的变化规律及以其作为反应时间控制参数的可行性,以便为解决SBR法的自动控制问题提供依据。
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