KR20030033812A - A Treatment Process For Livestock Wastewater - Google Patents

Abstract

PURPOSE: A high efficiency livestock wastewater treatment method is provided, in which treatment efficiency enhanced by recycling without any sludge settlement and additional treatment, and recalcitrant nonbiodegradable organics are treated by ozone/catalytic oxidation phase. CONSTITUTION: In the high efficiency livestock wastewater treatment system composed of a pretreatment tank, a chemical treatment tank, an anaerobic tank, a primary anoxic tank, a primary aerobic tank, a secondary anoxic tank, a secondary aerobic tank, an MBR (membrane bio-reactor), an ozone/catalytic oxidation tank and a zeolite tower, which are set serially, the treatment method is characterized in that a portion of the primary aerobic tank effluent is recycled to the primary anoxic tank, and the whole amount of the residual activated sludge of the MBR is recycled to the anaerobic tank.

Description

High Efficiency Livestock Wastewater Treatment Method {A Treatment Process For Livestock Wastewater}

The present invention relates to a method for treating high efficiency livestock wastewater, and more particularly, to an improved high efficiency livestock wastewater treatment method for improving treatment efficiency by sludge sedimentation and recycling without additional treatment.

Among the various causes of water pollution, livestock wastewater is known to be only 0.7% of total wastewater generation, but it is known to reach 8% as BOD, indicating the seriousness of water pollution caused by livestock wastewater.

Various methods have been introduced and implemented to prevent water pollution as described above. However, none of the methods have satisfied the current effluent standards. That is, organic matter in wastewater and nitrogen in organic matter are decomposed by microorganisms. is being purified is changed with water and C0 _2, the organic nitrogen is degraded by microorganisms in NH ₄ ⁺ -N nitride is in accordance with the amount of oxygen dissolved in water NO ₂ ^- -N and / or NO ₃ ^- -N state of nitrifying Is converted into a course

The NO ₂ ^-- N or NO ₃ ^-- N is decomposed into N ₂ , CO ₂ and H ₂ O in the presence of microorganisms and organic substances are purified by denitrification.

However, in the livestock wastewater, since nitrogen is relatively higher than COD, the denitrification and digestion process is not easy, and the high nitrogen concentration adversely affects the nitrifying microorganisms, making the nitrification process difficult.

The conventional livestock wastewater treatment method includes liquid corrosion method, PID oxidation method, natural purification method, aerobic digestion method, HAF method, SBR (Sequencing Bach Reactor) method and C-SBR method. There is a lot of economic problems, such as lack of economics, a large site is required, the need for reprocessing after the first treatment, or takes a lot of processing time.

The present invention has been made in order to solve the problems inherent in the treatment of high concentration livestock wastewater in the treatment of livestock wastewater as described above, the object of the present invention is to filter the treated water by suction, the residue is recycled It is to provide a treatment method without sludge generation.

Another object of the present invention is to repeatedly remove the oxygen and aerobic tank by internal circulation, the denitrification process and the nitrification process is repeated to remove the high concentration of nitrogen.

In order to achieve the above object, the present invention, in the treatment of high concentration livestock waste water, the treated water undergoing the anaerobic tank and aerobic tank to be internally circulated back to the previous anoxic tank, and then the anoxic tank, aerobic tank and membrane bioreactor (MBR: Membrane Bio-Reactor), suction filtration through the flat membrane, and the remaining activated sludge is returned to the anaerobic tank, a phosphorus removal tank.

1 is a schematic block diagram showing a treatment process of the present invention.

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

Figure 1 is a schematic block diagram showing the treatment process of the present invention, as shown, the high concentration livestock waste water after the pretreatment tank, chemical treatment tank, anaerobic tank, primary anaerobic tank, primary aerobic tank, the primary Internally circulated to an oxygen-free tank, and again subjected to a second anoxic tank, a second aerobic tank and a membrane bioreactor, the treated water suctioned by the flat membrane is treated using ozone and a catalyst, and discharged through a zeolite tower. The activated sludge which is not inhaled in the flat separator is, in turn, administered to the anaerobic tank and recirculated.

When the above-described step process is described in detail by process, in the pretreatment step, a screen is installed to separate the coarse impurities.

a. Drug Processing Step (DAF)

A process step for separating phosphorus by pressurized flotation and removing phosphorus by supplying alum or iron salt.

If by _{alum: Al 2 (SO 4) 3} + 2H 2 PO 4 - + 4HCO 3 - → AlPO 4 ↓ + 3SO 4 2- + 4H 2 CO 3

If due to _{iron: Fe 2 (SO 4) 3} + 2H 2 PO 4 - + 4HCO 3 - → 2FePO 4 ↓ + 3SO 4 2- + 4H 2 CO 3

b. Anaerobic Stage

Using the rich organics of the influent, the phosphorus-removing microorganisms cause excessive release of phosphorus.

Phosphorus release: poly-P → PO ₄ ^3- -P (energy release) in microorganism

PHB synthesis: Organic matter in sewage → microorganism PHB (energy storage)

c. First anaerobic treatment step

The first aerobic treatment is carried out using organic materials to denitrate nitrate nitrogen.

Denitrification: 2NO ₃ ^- + organic _{→ N 2 (↑) + CO} 2 + H 2 O

d. 1st exhalation stage

It functions as organic matter oxidation, nitrification, and excessive intake of phosphorus.

Organic matter oxidation: organic matter + O2 → CO2 + H ₂ O

^{_{Nitrification: NH 4 + + 2O 2 →}} NO 3 - + 2H + + H 2 O

Causal intake: nPO ₄ ^3- → poly-P

e. Second anaerobic treatment step

All of the nitrate nitrogen produced by the first aerobic treatment cannot be circulated internally to the first anoxic treatment tank, so the nitrate nitrogen introduced from the first aerobic treatment is denitrated by an external carbon source.

^{_{Denitrification: 6NO 3 - + 5CH 3 OH}} → 5CO 2 + 3N 2 + 7H 2 O + 6OH -

f. 2nd exhalation stage

Removal of residual organics, degassing of nitrogen gas, and further removal of phosphorus are carried out.

g. Membrane Bioreaction Step

A flat membrane separation is installed in the second aerobic tank, which is the second aerobic treatment step, to treat the treated water (SS up to 5 mg / L or less) by suction filtration.

h. Ozone / Catalyst Step

The ozone, which is a strong oxidant, is used together with the catalyst for the hardly decomposable organic substances in the treated water inhaled by the membrane separation, and is oxidized by the OH radical generated by the catalyst.

_{^{M n + + O 3 + H}} 2 O → M (n + 1) + + O 2 + OH - + · OH

RH + OH → R + H ₂ O

R + M ^{(n + 1) +} → R ⁺ + M ^{n +}

R · + O ₂ → ROO ·

ROO + RH → ROOH + R

^{R + + OH - → R-} OH

i. Zeolite Processing Steps

When the water temperature is room temperature, there is no problem in removing nitrogen as the treatment step, but in the winter when the water temperature is low, the treatment step alone is insufficient, and ammonia nitrogen is removed by physicochemical ion exchange in a zeolite tower.

NH ₄ ⁺ + ZB → Z-NH ₄ + B ⁺

The contaminants of the treatment result for the livestock wastewater treated through the above treatment process steps are shown in Table 1 below.

Table 1

(Unit: mg / L)

division BOD COD _Mn SS T-N T-P Remarks enemy 15,000 13,000 1,500 3,500 250 Bioreactor 40 210 4 15 2 Effluent 5 17 4 15 2

As described above, the present invention provides an improved livestock wastewater treatment method that satisfies the current effluent standards BOD 30 mg / L, COD 30 mg / L, SS 30 / mg, TN 120 mg / L and TP 16 mg / L. As a process step of, there is an effect of the fundamental solution of water and soil pollution, in particular, there is an effect that can be removed by the ozone / catalyst oxidation process step of difficult decomposition.

In addition, the process step of the present invention is not necessary because the sedimentation tank, there is an effect that can reduce the economic loss of maintenance due to sludge settling, livestock wastewater treatment has an hourly and seasonal load fluctuation, but can be accommodated actively and efficiently It works.

Claims (1)

In the high concentration livestock wastewater treatment method, a part of the treated water passing through the first anaerobic tank and the first aerobic tank is recirculated back to the first anoxic tank, and when the second anoxic tank and the second aerobic tank are passed, Livestock, characterized in that it comprises a process step of filtration treated by a flat membrane separation in an aerobic tank, the entire amount of remaining activated sludge is returned to the aerobic tank, and a process step of causing the filtered hardly decomposable material to be oxidized to ozone / catalyst. Wastewater Treatment