Análise sobre métodos de estimativa de pâramentos cinéticos em ensaios de degradação de matéria orgânica

Abstract

The pollutant degradation kinetics are sensitive topic, especially concerning the representation and mathematical interpretation of the process. The biodegradation of organic matter in water can be verified by BOD test, with deoxygenation estimated constant (KD) and BDOlast (LO). This study is to analyze and discuss the limits of these estimates. The study of different types of waters (WC raw sewage, polluted surface water and septic tank sludge) and respirometric data in the BOD test. The methodology applied for the determination of kinetic parameters considered the Thomas methods, Fujimoto, Least Squares and logarithms of the differences. Verification of the accuracy grade of the parameters, the kinetics first order model was obtained with different statistical indicators such as: Pearson correlation coefficient (r), mean square error (RMSE), because of variances (ABS), Pielke index (DPIELKE), Nash & Sutcliffe index (NSE), C2M index and concordance index (CI). The results suggested that probably no more distinction in procedure analytical than difference between the estimation methods. The Thomas method, however, is more attractive because it is simpler to apply. In parallel, the difference of the logarithms of the method presented, generally greater precision to represent the relationship between observed and predicted values. The study introduced unusual tools to verify the degree of dispersion of data (DPIELKE, NSE, C2M and IC). The results suggest that even for small samples, but accuracy of information, these features present great efficiency for comparing the simulated and observed fields.