HACH光度法测定不同废水中COD_(cr)消解时间的探讨

Study on Digestion Time of Sewage COD_(cr) by HACH Photometry

HACH光度法测定CODcr优势在于操作简便、试剂成本低、能批量分析等,但消解时间与国标法一致,仍为2 h。本实验根据废水组分的不同,缩短消解时间,从而快速、准确测定CODcr。结果表明:印染废水消解时间为20 min;化工、生活废水消解时间同为60 min;医药废水消解时间则为80 min。上述消解时间测定的样品,其准确度、精密度、加标回收率均达到质控要求。通过本方法与国标法比对试验表明,两种方法测定结果无显著性差异,因此可在实际工作中借鉴并推广。

The advantage of measuring CODor by HACH is easy to handle, low agent costs and feasibility of batch analysis, while the digestion time is still in accordance with international standard of 2h. This study shortens the digestion time so as to measure CODe, quickly and accurately. The results show that digestion time for printing and dyeing wastewater is 20min, for domestic sewage 60min, for pharmaceutical sewage 80min. The samples measured above meet the quality indicators such as accuracy, precision, and retrievability. By comparing the method with international measurement, there is no obvious discrepancy so it can be put into practice widely.