污水中COD与紫外吸光度A的相关性

The relevance between COD in the polluted water and the UV absorbance A

目的探讨污水中化学需氧量(chemical oxygen demand,COD)与紫外吸光度A值的相关性,验证紫外分光光度法测定COD的可行性。方法分别用重铬酸钾法和紫外分光光度计测定了污水中的COD及紫外吸光度A值。通过测量比较,数据拟合后,得出两者关系式。结果实验表明COD与紫外吸光度A值有良好的线性关系,其关系式为:COD(mg/L)=(A-0.00397)/0.03012,线性相关系数r≥0.9986。结论利用紫外分光光度法可以简便有效的检测污水中COD。

Objective： To explore the relevance between COD and the UV absorbance（A） of the polluted water and verify the feasibility that COD could be determined by UV spectrophotometry.Methods： Chemical oxygen demand was determined by potassium dichromate and the UV absorbance was determined by the UV spectrophotometer separately.The linear relationship between them was obtained by comparing and data fitting.Results： The results showed that the COD and the A value of the polluted water had a good linear relationship which was COD（mg/L） =（A-0.00397）/0.03012,with a good linear correlation coefficient greater than or equal to 0.9986.Conclusion： Using the ultraviolet spectrophotometer to determine chemical oxygen demand in wastewater is very simple and effective.