Otimização da análise de nitrogênio amoniacal em águas de reservatórios e caracterização do resíduo

Abstract

The ammonia nitrogen analysis, according to reaction of Berthelot, presents the problem of phenol use, compound that accumulates in organisms and can bring harm to health. Arising from this, the waste generated from this analysis are commonly stored so they are not dumped improperly. This work plan to optimize by reducing the production of waste and by reducing the use of phenol, and characterize the waste. Using the Berthelot method has been proposed to reduce proportionally the analysis to generate less waste, and to propose using varying amounts of phenol to compare the results. The characterization, some parameters were measured weekly for characterize the residue. The results indicated a 60% reduction in the generated volume. Also showed a situation of maximum absorbance at 640 nm by varying the amount of phenol to 2 ml. Furthermore, according to Koroleff methodology, the use of 0,08 mL of phenol generate a residue having much lower phenol concentration of the original procedure and is now held in this analysis 683 nm and comparative tests with the original methodology showed that It was efficient optimization, generating at the end 0,7 g L-1 of phenol (79,1% reduction from the original procedure). The study of the characterization indicated a decrease in pH, the total phenol and the absorbance at 640 nm with the passage of time, while the COD remained virtually constant during this period. With this work can be studied and determine ways to quantify NH3,4 with lower production of waste and reduced phenol concentration in these. The characterization presented behavior of parameters in waste, providing information for future treatment.