Method and equipment for treating and recycling reverse osmosis concentrated water and complex wastewater with high salt content

Abstract

The invention relates to a method and equipment for treating and recycling reverse osmosis concentrated water and complex wastewater with high salt content. The method comprises the following steps of: A. chemically treating raw water; B. separating chemically treated wastewater, wherein the chemically treated wastewater comprises 0.02-15 percent of solid in percentage by weight at an inlet of a film separating host machine; C. filtering the separated wastewater; and D. treating the filtered water by reverse osmosis. The equipment comprises a reaction device, a concentrator, a boosting pump, a separating host machine, a filter and a reverse osmosis host machine, wherein the reaction device comprises a chemical reactor and a medicament doser; and the separating host machine is a pipe type mould separating host machine. The invention has the outstanding advantages of improvement on the removal rate of heavy metal ions, hardness ions, silicon ions and COD (chemical oxygen demand) and the recovery rate of the wastewater, reduction of reverse osmosis film scaling, silicon scale pollution and biological pollution, inhibition of secondary pollution, less occupation of integral equipment, compact structure, simple operation and low running cost.

Description

technical field [0001] The invention relates to a method and equipment for treating and reusing reverse osmosis concentrated water and high-salinity complex wastewater, and is a method and equipment for treating and reusing reverse osmosis concentrated water and high-salt-content complex wastewater with an ultra-high recovery rate membrane system . Background technique: [0002] The existing reverse osmosis technology for sewage treatment has the following disadvantages: [0003] 1. Reverse osmosis technology has been widely used in the field of water desalination treatment with its stable desalination rate of 98%, but its recovery rate is only 70-80%, so that 20-30% of reverse osmosis concentrated water is discharged. It causes a very large waste of water resources; and the reverse osmosis concentrated water contains high salt content and a large amount of calcium and magnesium scaling ions, heavy metal ions, silicon ions and other special substances. At this stage, the re...

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Problems solved by technology

In China, the patent number is ZL200920115523.5, the name is "Reverse Osmosis Concentrated Water Reuse Device", and the Chinese Patent Number is ZL200820232440.X, the name is "A Membrane Filtration Device for Treating Reverse Osmosis Concentrated Water", and there are also Chinese patents No. ZL200820168798.0, titled "Reverse Osmosis Concentrated Water Recycling Device" and other existing technologies, in the related research on reverse osmosis concentrated water recycling, their common feature is: directly add scale inhibitor and reverse osmosis concentrated water For other chemical agents, the pH value is controlled to be less than 9, thereby inhibiting the precipitation of heavy metal ions and calcium and magnesium hardness ions on the surface of the concentrated water reverse osmosis membrane behind, so as to achieve the purpose of reusing reverse osmosis concentrated water; the disadvantages of the above-mentioned technical process are: Suppress and disperse heavy metal ions and hardness ions that may cause scaling by antiscalants and other chemicals; primary reverse osmosis concentrated water is high-salt water that has been concentrated 4 times from raw water, all heavy metal ions, calcium and magnesium hardness The concentration of ions, silicon, COD and other pollutants is already very high, which has already exceeded the saturation concentration product of each ion. The antiscalant is added to the first-stage reverse osmosis system to prevent the scale pollution from exceeding the saturation concentration product; now The above-mentioned process technology adds antiscalants to reverse osmosis concentrated water, and there are the following problems: first, excessive addition of antiscalants will cause the generation of other pollutants and cause secondary pollution; second, the ion concentration is too high, However, the antiscalant cannot achieve the purpose of antiscaling; third, it has no effect on COD removal; fourth, the recovery rate of the reverse osmosis system is low

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