Abstract:

The multilevel bio-system which was composed of three parts, suspension of the immobilized biofilm structure of the artificial substrates, cultivation of the floating-bed -vegation and submerged macrophyte, was used to restore the intensive ponds. And the method of principal component analysis (PCA) was used to assess the restoration effect. The results showed that the using of the multilevel bio-system made the integrated scores of principal components drop to a low level, which meant that after the technology referred above being used, the comprehensive status of the water quality of intensive ponds got better. The further analysis with PCA also showed that the main nutrition factor making the ponds eutrophicatin was the N element, and the organic ingredients were the key factor of oxygen consumption. To sum up, the method of PCA can be used to assess the restoration effect of external purifying technology.