extremely significantp < 0.001
The correlation analysis demonstrated that Proteobacteria , the first dominant phylum, was positively correlated with almost all the environmental factors, among which SBR and GLU had the highest correlation, all of which reached an extremely significant level ( p < 0.001); POXC and AK ( p < 0.01); and TOC, UA, and CA ( p < 0.05).