JPH01307488A - Treatment of trihalomethane in waste water - Google Patents

Abstract

PURPOSE:To efficiently remove trihalomethane in waste water by aerating the water with spray nozzles, treating the aerated water with activated carbon, dehumidifying and exhausting generated gas. CONSTITUTION:Waste water contg. trihalomethane is stored in a storage tank 2 from a raw water inlet 1 and a aerated with spray nozzles 4 arranged at regular intervals so as to increase vapor-liq. contact area. The aerated water is discharged from a water outlet 5 and filtered with an activated carbon bed 7 in an activated carbon treatment vessel 6. By this filtration, a very small amt. of trihalomethane is nearly perfectly adsorbed and water freed of trihalomethane is discharged from a water outlet 10. A dehumidifier 11 prevents water sprayed from the nozzles 4 from entering the exhaust port of an exhaust tower 12. Thus, the trihalomethane in the waste water can be efficiently removed.

Description

Detailed Description of the Invention [Field of Industrial Application] This article describes a method for treating trihalomethane in wastewater from a water separator installed in a recovery device for trihalomethane such as trichlorethylene and 1-1,1) dichloroethane. Removes trihalomethane from wastewater, which is said to occur in very small amounts.
Concerning methods for treating trihalomethanes in wastewater [Prior technology] Recently, prevention of underground contamination of trihalomethanes and their compounds has been further strengthened, and 70 special removal techniques are required.

A particular problem is that trace amounts of trihalomethane are discharged from the water separator of the 1-collection equipment. For example, in the case of trichlorethylene, the concentration ranges from 500 to 1,000 Ppm, which is 1/10 of the regulatory value. The following targets, for example, when discharging into public waters, trichlorethylene 0.031) I) m% 1 or less.

1.L trichloroethine is required to be treated to less than 1,000 sppm as a countermeasure against underground contamination.

Conventionally, in order to remove trace amounts of trihalomethane dissolved in water, only aeration using an aeration tank of the gas-liquid contact method has been used.

[Problem to be solved by the invention]

The above-mentioned conventional method mainly uses a gas-liquid contact method using an airage tank, so it does not meet the regulatory value standard.
/l O or less at once requires a large air flow rate, which requires the use of a large fan, which has the disadvantage of placing a large load on a small and compact aeration tank. In addition, the gas generated with the gas-liquid contact method is a mistake) (m
ist), and the humid gas is directly returned to the trihalomethane recovery equipment through the exhaust port, which has the drawback that the operation status of the recovery equipment is likely to be disturbed. The purpose of the present invention is to solve the above-mentioned drawbacks. It is an object of the present invention to provide a method for treating trihalomethane in wastewater, which can remove trihalomethane in wastewater efficiently in a short time.

[Means to solve the problem]

The method for treating trihalomethane in wastewater of the present invention involves performing aeration treatment using a spray nozzle that allows the wastewater containing trihalomethane to be circulated in a storage tank, then treating it with activated carbon, and dehumidifying the gas generated by the four-gas treatment. Furthermore, it is constructed with means for draining water.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of one embodiment of the present invention.

The embodiment of FIG. 1 has a raw water population of 1. Reservoir fi2 where passive water is stored from raw water population 1. Pump 3 that circulates the raw water in the storage tank 2 and forcibly pushes it out. 4. Spray nozzles installed at regular intervals to increase the contact area of gas and liquid inside the storage tank 2. 5. A water outlet for draining the water from which trihalomethane has been removed to some extent by the spray nozzle 4 in an overflow state. Activated carbon treatment tank 6, activated carbon tank 7 that constitutes the activated carbon treatment tank 6, and filter material 8. A valve 9 that discharges the raw water purified by the activated carbon treatment tank 6. Water outlet 10. Dehumidifier 11 that removes the sprayed moisture coming out of the spray nozzle 4. Next, the operation of the embodiment shown in FIG. 1 will be explained. The main points of the method for treating trihalomethane in waste water according to the embodiment shown in FIG. By using a gas-liquid contact method using a nozzle, it is possible to obtain the same performance as an airage system without requiring a large air flow rate. By doing this, trihalomethane in wastewater is almost completely adsorbed, and for example, in the case of trichlorethylene, it is always below the quantification limit (0,001 ppm, 1/1/2 of the regulatory standard value).
This provides an efficient function that can remove up to 300).

In addition, by installing a dehumidifier in the drainage duct, it is possible to remove the atomized moisture emitted from the spray nozzle during gas-liquid contact, and only the gas is returned to the recovery device through the exhaust port. Therefore, the normal operation of the trihalomethane recovery equipment is ensured.

In the embodiment shown in FIG. 1, wastewater containing trihalomethane is pumped from raw water 1 to a storage tank 2. A pump 3 circulates the wastewater in the storage tank 2 and forcibly pushes out the wastewater.

The spray nozzles 4 are installed at regular intervals to increase the contact area of gas and liquid, and the waste water from which the 4-degree trihalomethane has been removed is discharged from the water outlet 5 in an overflow format.

The activated carbon treatment tank 6 filters the water coming out of the water outlet 5 through an activated carbon layer 7, thereby almost completely adsorbing trace amounts of trihalomethane.

The filtering material 8 is a member that drains the water from which trihalomethane has been completely removed by opening the pulp 9 and filtering it to prevent the mixture of activated carbon, and is made of a material that is resistant to antifouling agents such as glass core or quartz wool. is used.

The water from which trihalomethane has been completely adsorbed and removed by the activated carbon layer 7 is discharged from the water outlet 11 ◎The dehumidifier 11 serves to prevent water in the form of atomized water emitted from the spray nozzle 4 from entering the exhaust port of the exhaust tower 12. to play. When the trihalomethane in the waste water is sprayed from the spray nozzle 4, the liquid phase is volatilized into the gas phase, and the gaseous state is forcibly discharged from the exhaust tower 12 by the electric fan 13. In addition, the discharged trihalomethane gas, such as trichlorethylene gas, is returned to the recovery device and recovered. In this way, aeration treatment is performed using a spray nozzle that allows the wastewater containing trihalomethane to be circulated in the storage tank. By utilizing this and discharging the gas generated by the aeration treatment after moisture-proofing), trihalomethane in wastewater can be treated quickly and efficiently.〇 [Effects of the Invention] As explained above. As you did, Ki-nii I! #1 is by using a combination of aeration treatment using a spray nozzle and subsequent activated carbon treatment, and removing and discharging the gas generated by the aeration treatment)
This method has the effect that trihalomethane in wastewater can be treated in a short period of time with extremely high removal efficiency.

For example, the population concentration of trichlorethylene is 500 to 1.0
00 ppm was below the outlet concentration of 0.01 ppm (quantification limit), and the removal effect was approximately 100 ppm.@Also, there was a problem when the gas generated by conventional gas-liquid contact was returned to the trihalomethane recovery device from the exhaust port. The dehumidifier has the effect of solving the problem of moisture caused by the generation of mist.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of today's embodiment. l...Raw water inlet, 2...Storage tank, 3.
・Group: Pump, 4: Spray nozzle, 5: Old: Water outlet, 6: Old: Activated carbon treatment tank, 7:...
Activated carbon layer, 8... Filter material, 9... Pulp, 10... Water outlet, 11... Dehumidifier, 12... Drainage Tower, 13...1 moving fan. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] The waste water containing trihalomethane is aerated using a spray nozzle that can be circulated in a storage tank, and then treated with activated carbon, and the wastewater generated by the aeration is dehumidified and then discharged. A method for treating trihalomethanes in wastewater.