KR20010003936A - Advanced Sewage and Wastewater Treatment Process using the Autotrophic Denitrifiers - Google Patents

Abstract

PURPOSE: An advanced wastewater treatment is provided to reduce management costs by using sulfide instead of exterior carbon sources (such as methanol, acetic acid). According to this method, Thiobacillus oxidizes sulfide (S¬-2, S, S2O3¬-2, S4O6¬-2, SO36-2) to SO4¬-2, therefore NO3¬- is reduced to nitrogen gas like these: NO3¬- + 1.1 OS + 0.4 CO2 + 0.76 H2O + 0.08 NH4¬+ --> 0.5 N2 + 1.1 SO4¬-2 + 1.28 H¬+ + 0.08 C5H7O2N. In above chemical reaction, NO3¬- is used as electron acceptor, and sulfide is used as energy source. Therefore, nitrogen gas is produced. CONSTITUTION: The system is characterized by comprising the following parts: a nitrification tank (2) in aerobic condition by a diffuser (4); a sedimentation basin (5) for separating sludge; a return pipe (6) for recycling a portion of sludge of the sedimentation tank (5) to the nitrification tank (2), for control of microorganism concentration; a lime injection device (11), installed ahead of the sedimentation tank (5), for supplementation of alkalinity; a denitrification tank (8) packed with sulfide granules (10) having Thiobacillus at the surface thereof.

Description

Advanced Sewage and Wastewater Treatment Process using the Autotrophic Denitrifiers}

The present invention relates to a high sewage and wastewater treatment method using a denitrified independent nutrient microorganism capable of reducing maintenance costs by replacing external carbon sources to remove nitrogen present in sewage and wastewater.

In general, many developed countries have developed wastewater and wastewater treatment methods suitable for their characteristics for hundreds of years, and based on their experience and technology, they have been targeting the environmental market of various countries. Significantly different relationships have resulted in many economic and time losses in adapting and adapting to the reality of the country.

Conventionally, an external carbon source is used to treat sewage and wastewater, and a sewage and wastewater treatment apparatus using pre-denitrification and post-denitrification processes in which methanol, acetic acid, etc., used as an external carbon source is used, requires excessive chemical costs and changes in raw water properties. As a result, when excessively injected, the water quality may be deteriorated (contamination) due to the effluent, and additional treatment facilities such as the 4-stage or 5-stage Bardenpho process are required.

Therefore, the present invention was created for the purpose of improving the above-mentioned conventional problems. Instead of external carbon sources (methanol, acetic acid, etc.) that have been used as electron donors in the process of denitrifying microorganisms (Thiobacillus strains) for denitrifying nitric oxide, The application of the principle of converting NO ₃ ^- into nitrogen gas while oxidizing sulfur compounds (S ^2- , S, S ₂ O ₃ ^2- , S ₄ O ₆ ^2- , SO ₃ ^2- ) to SO ₄ ^2- The scheme is shown below.

^{_{NO 3 - + 1.1OS + 0.40CO 2}} + 0.76H 2 O + 0.08NH 4 + →

0.5N ₂ + 1.10SO ₄ ^2- + 1.28H ⁺ + 0.08C ₅ H ₇ O ₂ N

As described above, the present invention is a method of generating nitrogen gas using the electron acceptor NO ₃ ^- and using sulfur as an energy source, so it is an acid-producing reaction and consumes alkalinity in the water, in this case limestone and the like with sulfur It is possible to replenish alkaline by filling it, and to provide a way to treat wastewater.

1 is a schematic diagram of the upflow desulfurization process of the present invention

Figure 2 is a schematic diagram of the downflow desulfurization process of the present invention

Figure 3 is a schematic diagram of the upflow type denitrification process containing a pH adjustment tank of the present invention

Figure 4 is a schematic diagram of the present upflow desulfurization process is installed the effluent internal circulation pipe of the present invention

* Explanation of symbols for main parts of the drawings

(1) Influent (2) Nitrifier

(3) air piping (4) diffuser

(5) Sedimentation basin (6) Nitric oxide return piping

(7) sludge waste piping (8) denitrification tank

(9) Pressurized pumps (10) Sulfur particles

(11) Limestone injection device (12) Backwashing line

(13) pH adjusting tank (14) Effluent

(15) effluent internal circulation pipe

Hereinafter, the configuration and operation of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an upflow desulfurization process of the present invention, Figure 2 is a schematic diagram of a downflow desulfurization process of the present invention, Figure 3 is a schematic diagram of an upflow desulfurization process including a pH adjustment tank of the present invention, Figure 4 is Schematic diagram of this upflow type denitrification process is installed the effluent internal circulation pipe of the present invention.

As shown in FIG. 1, the present invention is characterized by the aerobic reaction of oxygen injected into the diffuser (4) through the air pipe (3) from the nitrification tank (2) to the inlet water (1) Some of the lower sludge in the sedimentation basin (5) to induce nitrification and return to the nitrification tank (2) using the nitric oxide return pipe (6) for controlling the concentration of microorganisms and the rest is discharged through the sludge waste pipe (7) Alkaline is consumed during denitrification and phosphorus is strictly regulated. Limestone injector 11 is added to the sedimentation basin (5) at the front of the sedimentation basin to supplement alkali and phosphorus removal. When injected into the upstream denitrification tank (8) is to be denitrated by the denitrification bacteria attached to the surface of the sulfur particles (10).

In terms of reaction rate, sulfur in powder form is effective, but crushed stone is advantageous in terms of maintenance.

2 is the same as the upflow denitrification process described above, but considering the relationship and hydraulic gradient of the inflow direction of the denitrification tank 8 is a downflow denitrification process proceeding from the top to the bottom pressure by natural methods There is a difference in that the pump 9 can be omitted.

In FIG. 3, denitrification including an apparatus for backwashing the backwash line 12 using the treated water having the pH adjusting tank 13 placed at the rear end of the denitrification tank 8 when the filling of the alkaline supplement material is not appropriate is performed. It is a process.

In Figure 4 is a desulfurization process that can prevent the loss of sulfur particles by installing the effluent internal circulation pipe 15 for reuse of sulfur compounds present in the effluent (14).

Compared with the conventional 5-step Badenpo process injecting methanol to the external carbon source and the denitrification process of the present invention, the chemical costs for treating 1 g of NO ₃ ^-- N are simply 1.566 won and 0.750 won, the denitrification process of the present invention can reduce the chemical cost, thereby reducing the maintenance cost, and can replace the external carbon source to mitigate water pollution, and to efficiently treat the nitrogen present in the waste water, etc. It works.

Claims (4)

Inflow water (1), such as primary sedimentation effluent or sedimentation effluent, induces nitrification by an aerobic reaction due to the oxygen injected from the nitrification tank (2) into the diffuser (4) through the air pipe (3). Some of the lower sludge precipitated at is returned to the nitrification tank (2) by using the nitrifying liquid return pipe (6) to control the concentration of microorganisms, and the remainder is discharged through the sludge waste piping (7), and alkalinity is consumed during the denitrification reaction. When the limestone injector 11 at the front of the sedimentation basin (5) is added, the alkalinity replenishment and phosphorus removal are performed in parallel, and the sedimentation basin (5) supernatant is injected into the upstream denitrification tank (8) using a pressure pump (9). 10) Advanced wastewater and wastewater using the denitrifying independent nutrient microorganism, characterized in that the denitrification by the denitrifying bacteria attached to the surface of 10). The method of claim 1, Advanced sewage and wastewater using the denitrification independent nutritional microorganism, characterized in that proceeding from the top of the downflow type denitrification tank (8) to the bottom in the sedimentation basin (5). The method of claim 1, High pH treatment method for wastewater and wastewater using a denitrified independent nutrient microorganism, characterized in that the pH of the desulfurization tank (8) is installed at the rear end of the desulfurization tank (8) to backwash the adjusted water to the backwash line (12). The method of claim 1, Process for advanced sewage and wastewater using the denitrifying independent nutrient microorganism, characterized in that for installing the internal circulation pipe (15) in the effluent water to prevent the loss of sulfur particles.