Because of the large quantity and high COD value, the black liquor of paper making industry is an important source of environmental pollution.

造纸黑液由于量大、COD高，是造纸废水中的主要污染源，未经处理的黑液对环境会产生极大的危害。

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For a pollution source with the installation of automatic monitoring equipment, the COD and volume of sulfur dioxide emissions shall be reported on the basis of the automatic monitoring data.

对于安装自动监测设备的污染源以自动监测数据为依据申报化学需氧量和二氧化硫的排放量。

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Secondly, denitrification rate is improved because the oxygen pool is before the anaerobic pool and the anaerobic denitrifying bacteria readily biodegradable COD as carbon source;

第二，缺氧池与厌氧池位置互换，使得反硝化菌优先获得易降解有机物作为碳源，反硝化速率得到提高；

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