The traditional biochemical treatment of printing and dyeing wastewater has limited efficiency. This study investigated whether H2O2 could strengthen the biological ability of the hydrolytic acidification/biological contact oxidation process (A/O), which effectively treats the printing and dyeing wastewater. After biofilm formation and the biochemical system startup and operation by H2O2, the system was successfully started and steadily operated when H2O2was added into reactor A with the H2O2 voluve fraction of 3 mL·L-1, doses of 100.0 mL, the flow velocity of 0.67 mL·min-1, and dosing frequency of once a day. The experimental results showed that the average removal efficiencies of COD, ammonia nitrogen, PVA, and color of printing and dyeing wastewater were 89.8%, 96.7%, 87.4%, and 92.1%, respectively. The microorganism community structures of reactor A and reactor O in this system were analyzed by high-throughput sequencing of 16S rDNA amplicon. The results demonstrated that the three dominant microbial strains in reactor A were Proteobacteria, Bacteroidetes, and Verrucomicrobia, and in reactor O were Planctomycetes, Proteobacteria, and Acidobacteria.
Keywords: 16S rDNA sequencing; H2O2; biological contact oxidation; hydrolytic acidification; microorganism community structure; printing and dyeing wastewater.