Development of a novel advanced treatment process for high-algae-laden reservoir water: Performance and mechanism

A novel inverted advanced treatment process of ozone/hydrogen peroxide (O₃/H₂O₂) and biological activated carbon fluidized bed (BACFB) before the conventional process has been developed to treat the high-algae-laden reservoir water, which aims to enhance the removal of dissolved organic matter (DOM), odorants as well as the precursors of disinfection by-products (DBPs). Before and after the renovation, the average value of chemical oxygen demand (determined by potassium permanganate method) in the filter effluent decreased from 2.18 to 1.15 mg/L. Likewise, the average concentrations of turbidity dropped from 0.640 to 0.098 NTU, indicating substantial improvement following the renovation. Formation potential of DBPs such as trihalomethanes and haloacetic acids were also reduced greatly. The results of the polarity rapid analysis method indicated that ozonation primarily removed non-polar and positively charged organic matter, while coagulation-sedimentation targeted non-positive organic matter. The results of fluorescence spectroscopy and high-resolution mass spectrometry indicated that the new process effectively removed DOM, and decreased the number of nitrogen-containing compounds. Additionally, the inverted O₃/H₂O₂ and BACFB process promoted the dynamic transformation between DOM components and significantly reduced overall aromatic content. This study provided a promising solution for treating high-algae-laden source water and verified the feasibility and effectiveness of this novel process in practice.