EFFICIENCY OF REMOVAL IN STABILIZATION PONDS .2. STATISTICAL-ANALYSISOF K VALUES

The analytical values obtained from five WSP systems located in differ ent ecoclimatic zones in the centre and South of Portugal, were subjec ted to a statistical analysis of K and K-20 values (as used in the van Hoff-Arrhenius equation) utilizing an analysis of variance and a vect orial analysis of principal components. Significant differences betwee n K and K-20 values in facultative, maturation ponds and in the whole system were verified. The projection of the first principal components of eigenvectors made possible the classification of die stations,show ing the existence of similarities and discrepancies in their removal B OD kinetics behaviour. The K-20 value must be estimated and taken into account for the design of waste stabilization ponds.