Determination of biochemical oxygen demand(BOD_5) in water samples by potassium iodate-starch spectrophotometry

TLDR: In this paper, a method of determining BOD5 in water by potassium iodate-starch spectrophotometry was built on the reaction between KIO3 which employed as the standard solution and excessive KI.

Abstract: The biochemical oxygen demand(BOD) is an important parameter in reflecting the water quality in the environmental monitoring.The method of determining BOD5 in water by potassium iodate-starch spectrophotometry was built on the reaction between KIO3 which employed as the standard solution and excessive KI.The released I2 could react with the starch to form a blue complex,which had the maximum absorbance at 574 nm.BOD5 in water could be calculated through the amount of dissolved oxygen before and after 5 days determined.The method was used to the determination of biochemical oxygen demand in different water samples,such as BOD5 standard sample,glucose-glutamic acid solution and influent and effluent water from waste water factory and the results were in agreement with those of the national standard method.