A self-provided power plant intends to use the reverse osmosis(RO) desalination after mixing the main circulating water sewage of the power plant with the reverse osmosis concentrated water of the pure water station for comprehensive recovery and utilization. However

due to the complex quality of the waste water

in which the concentration of scaling ions and COD is high

the waste water must be effectively pretreated to reduce the risk of scaling and organic fouling on the membrane surface before entering the RO system. To solve the existing problems

this paper employs the process of "lime softening-high efficiency fiber filtering-ultrafiltration" to treat the circulating water sewage water and reverse osmosis concentrated water of water stations of the power plant. The influence of adding acid to regulate the pH value and the sequence of entering the high efficiency fiber filter on the pretreatment effect was discussed

and the optimum pretreatment process was determined. Keeping the turbidity of the pretreatment effluent water be below 2 and SDI below 3 will meet the requirements of reverse osmosis system.