Bittern or seawater ultrafiltration pre-treatment process and system

Abstract

The invention discloses a bittern or seawater ultrafiltration pre-treatment process and system. The bittern or seawater ultrafiltration pre-treatment process and system can provide filtered water meeting water feeding requirements of nanofiltration. Every process cycle of the bittern or seawater ultrafiltration pre-treatment process sequentially comprises a filtering step, a water producing step, a cleaning step and a discharging step, wherein the cleaning step comprises processes including gas wiping, gas-water backwashing and gas exhausting. Bittern or seawater is filtered through a cartridge filter and precisely-filtered liquor is filtered through a ultrafilter membrane filtering device to produce water; the gas exhausting process comprises that, during a membrane module exhaust process, oilless compressed air is inlet to the water inlet side of membrane yarns, and compressed air and water are mixed and oscillated to act on the surface of the membrane yarns; during the gas exhaust process, the water level decreases continuously, the gas-water washing strengths of the cross sections at different horizontal heights change, so that the membrane yarns can be cleaned from top to bottom. The bittern or seawater ultrafiltration pre-treatment process enables the bittern and seawater to be treated in a membrane filtering mode, thereby reducing the purification cost and simplifying the purification process, and through stable water output, prolongs the service life of nanofiltration membranes and guarantees stable operation of a nanofiltration system.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to a brine or seawater ultrafiltration pretreatment process and a pretreatment system. Background technique [0002] Brine is rich in chemical resources, with a salt content as high as 2-6 times that of seawater. The largest content is sodium chloride, which is the basic raw material for the soda ash manufacturing industry. The brine can be effectively removed through the brine nanofiltration refining process Calcium, magnesium, and sulfate ions, and the water produced is used for chemical salt in the soda industry, which will greatly reduce the amount of raw salt in chemical salt production and reduce the cost of soda ash production. The water quality of brine is complex, and there are impurities such as suspended solids and microorganisms in the water body, so pretreatment is required to meet the requirements of nanofiltration influent. [0003] At present, the pretreatme...

AI Technical Summary

Problems solved by technology

However, the water quality of brine is complex, and there are impurities such as suspended solids and microorganisms in the water body. For high-salt brine or seawater as the treatment object, the membrane method is used for treatment. The process and equipment design need to take into account the possible pollution and scaling of brine pretreatment risks, as well as the efficiency and feasibility of pretreatment, there is no mature technical solution suitable for membrane treatment of brine

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