Pressure delay osmosis/reverse osmosis combined desalination method

Abstract

The invention discloses a pressure delay osmosis / reverse osmosis combined desalination method, which comprises the following steps of: pressurizing pretreated sewage flow U, successively inputting into first and second pressure delay osmosis devices; pressurizing pretreated seawater flow A, entering into the first pressure delay osmosis device, outputting three flows D, E and F, inputting the flow D into a first energy recovery device for energy absorption, inputting into a first booster pump for supercharging, inputting the flow E into a second booster pump for supercharging, inputting the flow F into a second energy recovery device for energy absorption, inputting into a third booster pump for supercharging, merging the three flows, inputting into a high-pressure membrane module, outputting a strong brine flow P from the membrane module, inputting the flow P into the second energy recovery device to release energy, inputting into a fourth booster pump for supercharging, inputting into the second pressure delay osmosis device, inputting into the first energy recovery device to release energy, outputting product water out from the membrane module, and processing the product water for usage. The method provided by the invention is used to raise energy utilization rate, decrease energy consumption, save desalination cost and reduce discharge load of the strong brine.

Description

technical field [0001] The invention belongs to the field of desalination, in particular to a pressure-delayed osmosis / reverse osmosis combined desalination method. Background technique [0002] The increasing demand for water, the increasingly normal climate drought and the continuous deterioration of the water environment have caused a serious shortage of fresh water resources. The development of unconventional water sources is being studied and put into practice by countries all over the world. With the rapid development of our country's economy and society, the utilization of unconventional water sources has attracted widespread attention from all walks of life. For coastal cities and island areas, the development and utilization of unconventional water sources mainly include seawater desalination, sewage reuse and rainwater utilization. Due to various degrees of climate anomalies in many parts of the world in recent years, the local precipitation has dropped significan...

AI Technical Summary

Problems solved by technology

However, there are still many obstacles to the continuous progress of reverse osmosis desalination technology. The energy consumption of the reverse osmosis system needs to be reduced, and the water recovery rate of the system needs to be improved. This is the main reason why its water production cost has remained high for a long time

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