DERIVATIVE SPECTROPHOTOMETRY FOR NO3- DETERMINATION IN SANITARY SEWAGES

The aim of this research was to verify the use of Ultraviolet Spectrophotometric Screening Method on the analysis of nitrate-nitrogen in domestic wastewater samples, which is a method recommended to water samples with low organic matter contents. In order to do that, the results achieved with the aforementioned method were compared to the salicylate method that is largely used worldwide. The results observed from both methods were different according to Man-Whitney test (? = 5%). Nevertheless, such difference between them were less than 0,25 mg L-1 for half of the samples. Hence, the adoption of the UV spectrophotometric screening method to perform nitrate analyses on domestic wastewater samples seemed quite reasonable.