Removing organic matters from reverse osmosis concentrate using advanced oxidation-biological activated carbon process combined with Fe/humus-reducing bacteria.

The high-concentration wastewater produced in the industrial reverse osmosis (RO) process contains a large amount of refractory organic matters, which will have serious impacts on the natural environment and human health. Among them, contaminants can be transformed by humus-reducing bacteria based on humus. In this study, O- assisted UV-Fenton method was applied as pretreatment. Biological activated carbon (BAC) technology in which humus-reducing bacteria were the dominant bacteria, enhanced by electron donor and Fe, was used to dispose of RO concentrate (ROC). The results showed that water treatment process combining oxidation with biological filtration had a positive effect on the removal of stubborn contaminants in ROC. The system was strengthened by adding electron donor and Fe, and the chemical oxygen demand (COD) removal efficiency was up to 80.1%. However, when the removal efficiency of UV absorbing pollutants reached optimal value (87.3%), that means only Fe was added.