KR100193785B1 - Wastewater Treatment and Reuse Method using Microfiltration and Reverse Osmosis Membrane and Its Apparatus - Google Patents

Abstract

The present invention relates to a wastewater treatment and reuse method and apparatus therefor including hydrofluoric acid, and in the present invention, by treating hydrofluoric acid wastewater generated in an industrial site using microfiltration and reverse osmosis membrane, the wastewater is discharged without undergoing a separate filtration step. Recyclable industrial water. Hydrofluoric acid wastewater treatment method according to the present invention comprises the steps of adjusting the pH using a flocculant and at the same time solidifying fluorine fluoride ions contained in the acid wastewater and coarsening the solids formed by the flocculating aid; Separating the coarse solids in the step by microfiltration to discharge the solids containing the turbidity component and the treated water from which the solids are removed; Adsorbing and removing the organic matter contained in the treated water discharged in the step using activated carbon; And removing unreacted fluorine ions, other dissolved salts, and residual organic matters contained in the treated water from which the organic matter was removed using a reverse osmosis membrane to discharge the reusable treated water.

Description

Wastewater Treatment and Reuse Method using Microfiltration and Reverse Osmosis Membrane and Its Apparatus

The present invention relates to a method and apparatus for treating and recycling hydrofluoric acid wastewater.

Fluoride ions contained in hydrofluoric acid have been found to be toxic, and containing more than 3mg / l in water affects the aquatic ecosystem, and if it enters the human body, it can cause various diseases if abnormal in stomach, intestines, circulatory system and nervous system. Reported.

Hydrofluoric acid is used in the surface treatment, cleaning and etching processes in the electronics and aviation industries. Such conventional treatment of hydrofluoric acid wastewater solidifies and precipitates dissolved hydrofluoric acid by flocculation, precipitation, filtration or adsorption, and then discharges or selectively fluorine ions. It discharges after adsorption using the adsorption agent which adsorb | sucks.

The treatment method by flocculation and sedimentation method generates a lot of sludge, requires a large facility area, and satisfies the current legal effluent water quality standards, but has a high concentration of fluorine in the treated water, so a large amount of wastewater is discharged into small and medium streams. Can increase the load of pollutants and damage crops and fish.

The discharge method after adsorption using an adsorbent can reduce the fluorine concentration in the treated water, but requires a separate facility for adsorption and requires many chemicals for periodic regeneration, as well as interference such as aluminum ions. If there is a material has a disadvantage that the adsorption capacity is lowered. In addition, the method using the adsorbent has a large apparatus and a high regeneration frequency when the concentration of fluorine ions in the waste water is high, and requires a separate facility for treating the regeneration waste water.

In addition, the conventional hydrofluoric acid wastewater treatment method has a large amount of calcium ions in the treated water due to the calcium salt used in the hydrofluoric acid wastewater treatment, causing pipe corrosion when reused in heavy water, and other inorganic salts, organic matter, and turbidity components are not removed. Therefore, it cannot be reused as process water.

An object of the present invention is to eliminate the drawbacks of the above-described conventional methods, the treatment efficiency is high, can reduce the use of chemicals to reduce the amount of sludge generated and can produce treated water that can be reused as industrial water using a relatively simple equipment To provide a method and apparatus for treating and recycling hydrofluoric acid wastewater.

1 is a flowchart illustrating a hydrofluoric acid wastewater treatment and reuse method according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: reservoir 20: first flocculation reactor

30: first precision filter 40: activated carbon adsorber

50: reverse osmosis 60: the second flocculation reactor

70: second precision filter

In the hydrofluoric acid wastewater treatment method according to the present invention for achieving the above object, the pH of the hydrofluoric acid wastewater is adjusted by using a flocculant and a coagulant adjuvant, and the fluorine ions contained in the hydrofluoric acid wastewater are solidified to form fluorine compounds. Talking; Separating the coarse solids in the step by microfiltration to discharge the solids containing the turbidity component and the treated water from which the solids are removed; Adsorbing and removing the organic matter contained in the treated water discharged in the step using activated carbon; And removing the unreacted fluorine ions, other dissolved salts, and residual organic matters contained in the treated water from which the organic matter was removed using a reverse osmosis membrane to discharge the reusable treated water.

In the hydrofluoric acid wastewater treatment and reuse method according to the present invention, the step of adjusting the pH of hydrofluoric acid wastewater is characterized in that the pH of the hydrofluoric acid wastewater is adjusted to 5.0 to 7.5.

In addition, the hydrofluoric acid wastewater treatment and reuse apparatus according to the present invention for achieving the above object, by adjusting the pH of the hydrofluoric acid wastewater using a flocculant, to solidify the fluorine ions contained in the acid wastewater and to the flocculation aid An agglomeration reaction tank for coarsening the solids formed by the same; A fine filter for separating the solid coarse by the coagulation reaction tank by fine filtration to discharge the solids containing the turbidity component and the treated water from which the solids are removed; Activated carbon adsorber for removing the organic matter contained in the treated water discharged by the precision filter by using the activated carbon; And a reverse osmosis unit which removes unreacted fluorine ions, other dissolved salts, and residual organic substances contained in the treated water from which the organic matter is removed by the activated carbon adsorber using a reverse osmosis membrane to discharge the treated water for reuse.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a hydrofluoric acid treatment and reuse method according to an embodiment of the present invention.

The hydrofluoric acid wastewater is collected and stored in the reservoir 10. The hydrofluoric acid wastewater stored in the storage tank 10 is pH-adjusted by the flocculating agent in the first aggregation reaction tank 20, the turbidity component and the colloidal component are coarsened, and the fluorine ions are converted into a solidified fluorine compound. Preferred flocculants used are hydrated lime, calcium carbonate, polyaluminum chloride and the like. The pH is adjusted to 5.0 to 7.5 by the flocculant. In addition, the fluorine compound, the turbidity component, and the solid organic matter solidified by the polymer coagulant may be coarsened.

The hydrofluoric acid wastewater discharged from the first flocculation reactor 20 is introduced into the tubular first precision filter 30 having pores of 0.1 to 0.2 μm, and the solids are separated and separated by the first precision filter 30. The treated water discharged to the second agglomeration reactor 60 and the solids are removed is introduced into the activated carbon adsorber 40.

The activated carbon adsorber 40 adsorbs and removes organic substances contained in the treated water flowing from the first precision filter 30 using activated carbon. If the organic acid is not included in the hydrofluoric acid wastewater, the treatment by the activated carbon adsorber 40 may be omitted.

The reverse osmosis unit 50 removes unreacted fluorine ions, other dissolved salts, and residual organic substances contained in the treated water discharged from the activated carbon adsorber 40 using a reverse osmosis membrane to discharge the regenerated water, and is excluded by the reverse osmosis membrane and concentrated. The concentrated water containing the dissolved organic matter and salt is discharged to the second agglomeration reactor (60).

The second agglomeration reactor 60 solidifies and adsorbs the solids introduced from the first precision filter 30 and the concentrated water introduced from the reverse osmosis unit 50 using hydrated lime or calcium carbonate and polyaluminum chloride, and then polymers. The coagulation agent is coarsened and discharged to the second fine filter 70.

In the second precision filter 70, the wastewater containing the solids flowing from the second agglomeration reactor 60 is filtered and dewatered to discharge the filtrate, and the dehydrated solids are discharged as waste.

As described above, the hydrofluoric acid wastewater treatment and reuse method according to the present invention and the regenerated water discharged by the apparatus have better turbidity and maintain dissolved salt concentrations similar to those of industrial water. It can be reused as industrial water without going through. Therefore, there is an advantage that the water can be supplied without the initial investment and operating costs according to a separate filtering device. In addition, the treated water can be recycled and can reduce the amount of waste water discharged and the amount of industrial water used.

Claims (3)

In the hydrofluoric acid wastewater treatment and reuse method, Adjusting the pH of the hydrofluoric acid wastewater using a flocculant to solidify the fluorine ions contained in the hydrofluoric acid wastewater and to coarsen the solids formed by the flocculating aid; Separating the coarse solids in the step by microfiltration to discharge the solids containing the turbidity component and the treated water from which the solids are removed; Adsorbing and removing the organic matter contained in the treated water discharged in the step using activated carbon; And Treatment and reuse of hydrofluoric acid wastewater, characterized in that it comprises the step of removing the unreacted fluorine ion, other dissolved salts and residual organic matter contained in the treated water from which the organic matter was removed using a reverse osmosis membrane to discharge the reused treated water. Way. According to claim 1, wherein the step of adjusting the pH of the hydrofluoric acid wastewater hydrofluoric acid wastewater treatment and reuse method, characterized in that for adjusting the pH of the hydrofluoric acid wastewater is 5.0 to 7.5. In the wastewater treatment and reuse apparatus containing hydrofluoric acid, An agglomeration reaction tank which adjusts the pH of the hydrofluoric acid wastewater using a flocculant, solidifies the fluorine ions contained in the acid wastewater, and coarsens the solids formed by the flocculating aid; A fine filter for separating the solid coarse by the coagulation reaction tank by fine filtration to discharge the solids containing the turbidity component and the treated water from which the solids are removed; Activated carbon adsorber for removing the organic matter contained in the treated water discharged by the precision filter by using the activated carbon; And Foshan wastewater, characterized in that it comprises a reverse osmosis to remove the unreacted fluorine ions, other dissolved salts and residual organic matter contained in the treated water by the activated carbon adsorber using a reverse osmosis membrane to discharge the reused treated water Processing unit.

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