Pre-treatment method for sea salt water

Abstract

A method for pre-treating saline sea water comprises the following steps. Step 1, clarify, to produce a certain amount of slurry waste water and add a ''xianchaoling'' purifying agent in the saline sea water. The purifying agent is an ionic hydrocarbon polymer with the molecular weight of 8M-15M containing an alkali metal ferrate and an alkali metal aluminum carbonate salt and alkali metal ammonium phosphate mixed salt prepared in proportion by dissolving in an amine-contained alkali solution, which is slowly reduced to 65-90 degree and maintained for a certain period of time till strongly viscous high molecular polymer is produced. Step 2, ion exchange in ion-exchange apparatus. Step 3, put the saline sea water after step 2 in a desalting apparatus for desalting to produce the products concentrated water and plain water. Step 4, the concentrated water obtained in step 3 is partly used as industrial pure saline water and partly used as regeneration pure saline water which is returned to the ion-exchange apparatus in step 2 to regenerate the ion-exchange resin and then produce regeneration waste water.

Description

technical field [0001] The invention relates to a sea salt water desalination treatment method, in particular to a sea salt water pretreatment method. Background technique [0002] In the prior art, the desalination treatment of sea salt water generally adopts the technological process shown in Figure 1: [0003] Desalination in this technological process includes one or more combinations of electrodialysis, reverse osmosis, distillation and other equipment. The five processes before desalination in this technological process are collectively referred to as the pretreatment of sea salt water. This technological process has been widely used, and the fresh water output ranges from a few kilograms, hundreds of tons, to thousands of tons, and there are examples in operation all over the world. [0004] But this technological process has substantive defect: [0005] 1. Cannot remove scaling compounds in pretreatment water, resulting in high power consumption; [0006] The cla...

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Problems solved by technology

[0005] 1. Cannot remove scaling compounds in pretreatment water, resulting in high power consumption;

[0006] The clarifying agent it uses is a conventional aluminum-iron salt compound, such as aluminum sulfate, ferric chloride, aluminum chloride, etc., and its polymers. In salty water, its electric neutralization and clarification mechanism is very limited, not only the clarification effect is very poor, but also most of the scaling compounds in the water cannot be removed

Although antiscalants are added before desalination in the process, it only plays the role of complexing scaling compounds in water, trying to improve the solubility of scaling compounds in water, but hidden dangers still exist and the effect is limited

Scaling and clogging in the desalination equipment still occur frequently, resulting in frequent shutdown, dismantling and backwashing of the desalination system

And the membrane flux is reduced, so the energy consumption is high

[0007] 2. Low utilization rate of water resources;

[0009] 3. Wastewater resources cannot be effectively utilized;

[0010] The above three types of wastewater contain all the resources and pollutants in the sea and salt water except fresh water. Due to the large amount and mixed, it is currently impossible to purify and recycle at low cost. As a result, resources are wasted and the environment is polluted. The wastewater is discharged into the land Cause land salinization can not be restored

[0011] 4. The system is complex and requires a large investment;

[0012] The pretreatment part of this process flow includes 5 basic processes, and additional auxiliary equipment and automatic control system are required. The system is more complex, the reliability is worse, the probability of error and accident is high, and the investment is high.

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