Multivariate criteria applied in the performance of Tifton 85 grass in a constructed wetland: effects of organic, nutritional, and sodium loads from swine wastewater

Abstract

The purpose of this study was to analyze the effects of the application of multivariate criteria of principal components and hierarchical clustering as a mechanism for monitoring the performance of Tifton 85 grass (Cynodon spp.) planted in horizontal subsurface flow constructed wetland reactor (HSSF-CW) under different organic (OLR), nutritional and sodium loads of swine wastewater (SW). The HSSF-CW planted with Tifton 85 grass was used as a swine wastewater after treatment applying organic loading rates between 26.1 (1st cut) and 360.6 kg ha−1 day−1 COD (8th cut). The maximum performances of HSSF-CW consisted of 52.0 t ha−1 of productivity and 24.0% of crude protein, with the application of 59.7, 64.2, and 31.2 kg ha−1 day−1 of TKN, PT, and K+, respectively. The eleven original variables generated four new components, with PC4 accounting for 94.0% of total variance, a condition strengthened with four data groupings greater than 48% similarity and three data groupings greater than 95% similarity between the variables. There was a strong association between of nitrogen, phosphorus, and potassium concentration by the hierarchical grouping and the intermediate cuts and lower temperatures.