JP2015192949A - Installation and method for water treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for water treatment which enable efficient remove hydrogen sulfide in drain water.SOLUTION: A water treatment installation 1 conducts an anaerobic treatment of drain water in an anaerobic treatment tank 3 and aerating the to-be-treated water containing hydrogen sulfide generated by the anaerobic treatment in the anaerobic treatment tank 3, in an aerobic treatment tank 5 in the presence of sulfur-oxidizing bacteria so as to remove hydrogen sulfide efficiently with the sulfur-oxidizing bacteria activated by the aeration.

Description

  The present invention relates to a water treatment facility and a water treatment method.

  Conventionally, as a wastewater treatment method for treating organic wastewater such as domestic wastewater, a method of treating using anaerobic microorganisms is known (see, for example, Patent Document 1). According to the method described in Patent Document 1, organic wastewater containing sulfate ions is treated by anaerobic biological treatment, and hydrogen sulfide generated by the anaerobic biological treatment is oxidized by aeration.

JP 2005-296891 A

  However, since the wastewater treatment method described in Patent Document 1 is a wastewater treatment method limited to treating low-concentration organic wastewater, hydrogen sulfide in wastewater is efficiently used regardless of the concentration of organic wastewater. Removal is desired.

  Then, an object of this invention is to provide the water treatment apparatus and water treatment method which can remove the hydrogen sulfide in waste_water | drain efficiently.

  The water treatment apparatus according to the present invention includes an anaerobic treatment unit for anaerobically treating waste water, and hydrogen sulfide in the treated water by aeration in the presence of sulfur-oxidizing bacteria on the treated water supplied from the anaerobic treatment unit. And an aerobic treatment unit that oxidizes the water.

  According to the water treatment device of the present invention, the water to be treated containing hydrogen sulfide generated by the anaerobic treatment of the anaerobic treatment unit is aerated in the presence of sulfur-oxidizing bacteria in the aerobic treatment unit. Hydrogen sulfide is efficiently removed by the activated sulfur-oxidizing bacteria.

  Here, when aeration is performed with fine bubbles, the dissolved oxygen concentration in the water to be treated increases, so that the sulfur-oxidizing bacteria are further activated and hydrogen sulfide is more efficiently removed.

  Moreover, when the to-be-processed water supplied from an anaerobic process part is sealed and introduced into an aerobic process part, it can suppress that the hydrogen sulfide contained in to-be-processed water diffuses in the air.

  Moreover, the water treatment method according to the present invention is characterized in that hydrogen sulfide in the water to be treated is oxidized by aeration of the water to be treated containing sulfur oxidizing bacteria in the presence of the sulfur oxidizing bacteria. Also in such a water treatment method, as described above, since the water to be treated is aerated in the presence of sulfur-oxidizing bacteria, the sulfur-oxidizing bacteria are activated, and this sulfur-oxidizing bacteria efficiently converts hydrogen sulfide in the water to be treated. Removed.

  Thus, according to the present invention, it is possible to provide a water treatment apparatus and a water treatment method that can efficiently remove hydrogen sulfide in waste water.

It is a schematic structure figure showing water treatment equipment concerning an embodiment of the present invention. It is a figure of the 1st experiment result concerning the embodiment of the present invention. It is a figure of the 2nd experiment result concerning the embodiment of the present invention. It is a figure of the 3rd experimental result which concerns on embodiment of this invention.

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

  FIG. 1 is a schematic configuration diagram illustrating a water treatment facility according to an embodiment of the present invention. As shown in FIG. 1, the water treatment facility 1 treats waste water, and an anaerobic treatment tank 3 (anaerobic treatment part), an aerobic treatment tank 5 (aerobic treatment part), and these tanks. Lines L1 to L3 to be connected.

  The anaerobic treatment tank 3 accommodates anaerobic microorganisms in the tank 3, and anaerobically treats the wastewater supplied from the line L1 with the anaerobic microorganisms. The anaerobic treatment tank 3 is, for example, a methane fermentation tank.

  The aerobic treatment tank 5 accommodates sulfur-oxidizing bacteria in the tank 5 and aerobically treats the water to be treated supplied from the anaerobic treatment tank 3 through the line L2. The sulfur-oxidizing bacteria may be mixed in the wastewater introduced into the anaerobic treatment tank 3. The tank 5 does not contain activated sludge. Here, the discharge opening of the line L <b> 2 is located below the water surface of the aerobic treatment tank 5. That is, the water to be treated supplied from the anaerobic treatment tank 3 through the line L2 is sealed in the aerobic treatment tank 5 and introduced.

  The aerobic treatment tank 5 includes a blower B and a diffuser pipe P connected to the blower B, and feeds fine bubbles into the tank 5 from the diffuser port A opened in the diffuser pipe P. Examples of the fine bubbles include bubbles having a diameter of 1 mm or less. Here, the aeration time (HRT) of the water to be treated in the aerobic treatment tank 5 is 1 hour to 4 hours, preferably 3 hours or more. In the aerobic treatment tank 5, the load of hydrogen sulfide is 0.8 kg / kg · d or less, preferably 0.53 kg / kg · d or less. The hydrogen sulfide load represents the amount of sulfur relative to the amount of sulfur-oxidizing bacteria in the suspended substance per unit day.

  According to the water treatment facility 1 having such a configuration, wastewater is introduced into the anaerobic treatment tank 3 and hydrogen sulfide is generated by the anaerobic treatment. The treated water containing hydrogen sulfide is introduced into the aerobic treatment tank 5, and the treated water is aerated in the aerobic treatment tank 5 in the presence of sulfur oxidizing bacteria. By this aerated and activated sulfur-oxidizing bacterium, hydrogen sulfide in the water to be treated can be efficiently removed.

  Moreover, since aeration is performed with fine bubbles, the dissolved oxygen concentration in the water to be treated is increased, sulfur oxidizing bacteria are further activated, and hydrogen sulfide can be removed more efficiently.

  Moreover, since the to-be-treated water supplied from the anaerobic treatment tank 3 is sealed in the aerobic treatment tank 5 and introduced, hydrogen sulfide contained in the to-be-treated water can be prevented from diffusing.

  Here, the experimental result which processed the waste_water | drain using the water treatment facility 1 in this embodiment is demonstrated. 2-4 is a figure which shows the experimental result of the water treatment by the water treatment equipment 1 which concerns on embodiment of this invention.

  As a first experiment, the water treatment facility 1 was used to perform aeration with fine bubbles having a bubble diameter of 1 mm or less, and the relationship between the aeration time and the amount of hydrogen sulfide in the treated water was measured. The result is shown in FIG. The vertical axis in the figure represents the amount of hydrogen sulfide in the treated water, and the horizontal axis in the figure represents the aeration time. As shown in FIG. 2, in the treated water treated using the water treatment facility 1, the amount of hydrogen sulfide decreases as the aeration time becomes longer. When the aeration time is 3 hours or more, the amount of hydrogen sulfide Was found to be 0 mg / L.

  As a second experiment, the water treatment facility 1 was used to perform aeration with bubbles having a normal bubble diameter, and the relationship between the aeration time and the amount of hydrogen sulfide in the treated water was measured. The result is shown in FIG. The vertical axis in the figure represents the amount of hydrogen sulfide in the treated water, and the horizontal axis in the figure represents the aeration time. As shown in FIG. 3, the amount of hydrogen sulfide decreased as the aeration time increased, and it was confirmed that the amount of hydrogen sulfide was 0 mg / L when the aeration time was 4 hours or longer.

  Therefore, it was confirmed from the measurement results of the first and second experiments that hydrogen sulfide in the water to be treated can be efficiently removed in any case. In addition, the method of aerobic treatment of hydrogen sulfide by activated sludge treatment with normal size bubbles requires about 6 hours. In addition, the time required for the amount of hydrogen sulfide in the water to be treated to be 0 mg / L in the first experiment is required until the amount of hydrogen sulfide in the water to be treated in the second experiment is 0 mg / L. It was confirmed that it was shorter than the time taken.

  As a third experiment, the water treatment facility 1 was used to measure the relationship between the load of hydrogen sulfide and the treatment of hydrogen sulfide. The result is shown in FIG. The vertical axis in the figure represents the ratio (treatment rate) of hydrogen sulfide contained in the water to be treated, and the horizontal axis in the figure represents the load of hydrogen sulfide. As shown in FIG. 4, when the load is 0.8 kg / kg · d, approximately 60 percent of hydrogen sulfide is processed, and when the load is 0.53 kg / kg · d or less, approximately 100 percent of hydrogen sulfide is It was confirmed that it was processed.

  Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment and may be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Water treatment equipment, 3 ... Anaerobic treatment tank (anaerobic treatment part), 5 ... Aerobic treatment tank (aerobic treatment part).

Claims (4)

An anaerobic treatment section for anaerobically treating the waste water;
An aerobic treatment unit that oxidizes hydrogen sulfide in the treated water by performing aeration in the presence of sulfur-oxidizing bacteria on the treated water supplied from the anaerobic treatment unit;
A water treatment facility comprising:   The water treatment facility according to claim 1, wherein the aeration is performed by fine bubbles.   The water treatment facility according to claim 1 or 2, wherein the water to be treated supplied from the anaerobic treatment unit is introduced after being sealed in the aerobic treatment unit.   A water treatment method characterized by oxidizing hydrogen sulfide in water to be treated by aeration of the water to be treated containing sulfur oxidizing bacteria in the presence of the sulfur oxidizing bacteria.

Images