CN1468816A

CN1468816A - Catalytic oxydization and biochemical method and apparatus for treating waste water with hard-to-degrad organism

Info

Publication number: CN1468816A
Application number: CNA021361274A
Authority: CN
Inventors: 王罗春
Original assignee: Shanghai University of Electric Power
Current assignee: Shanghai University of Electric Power; Shanghai Electric Power University
Priority date: 2002-07-19
Filing date: 2002-07-19
Publication date: 2004-01-21

Abstract

The present invention is catalytic oxidization and biochemical method and apparatus for treating hard-to-degrade organic waste water. The present invention features that organic waste water is first chemically oxidized in the presence of catalyst to convert into organic waste water capable of being biochemically degraded and then biochemically treated in a mineralized garbage bioreactor, resulting in lower treating cost. The present invention has scientific treating process, reasonable structure, low treating cost, high treating effect and can lower CODCr of waste water to below 100 mg/L.

Description

Method and device for treating refractory organic wastewater by combining catalytic oxidation and biochemistry

Technical Field

The invention relates to a method and a device for treating refractory organic wastewater by combining a chemical method and a biological method.

Background

The treatment of organic wastewater difficult to be biochemically degraded is always a problem faced by sewage treatment, namely a popular subject of research in recent years. People generally use two types of methods for treatment: firstly, the organic matters difficult to degrade are completely oxidized into inorganicmatters and CO by utilizing pure chemical oxidation methods such as ozone, Fenton reagent or UV/Fenton reagent and the like under certain conditions₂、H₂O; firstly, the organic matter which is difficult to degrade is partially oxidized into organic matter which can be biochemically degraded and CO by utilizing pure chemical oxidation methods such as ozone, Fenton reagent or UV/Fenton reagent and the like under certain conditions₂、H₂O, then using anaerobic method or active sludge method to make subsequent biological treatment to make the bio-degradable organic material be completely mineralized and changed into inorganic material and CO₂、H₂And O. However, most of the above methods are in experimental stage and have not been put into productive application.

The invention aims to provide a method and a device for treating organic wastewater difficult to biochemically degrade, which are subjected to catalytic oxidation reaction and subsequent biochemical treatment, have low treatment cost and can reach the standard.

The technical scheme of the invention is realized by that the method and the device thereof make the processed organic wastewater which is difficult to be biochemically degraded be firstly converted into organic wastewater which can be biochemically degraded by chemical oxidation under the condition of a catalyst, and then be processed by a mineralized refuse bioreactor for subsequent biochemical treatment. The method comprises the following steps:

(1) adjusting the pH value of the treated water to 2.0, and adding an oxidant and a catalyst into the wastewater;

(2) after the catalytic oxidation reaction is finished, adjusting the pH value of the treated water to be about 7.0;

(3) biologically inoculating the mineralized refuse bioreactor with domestic sewage until the quality of the effluent is stable while the steps (1) and (2) are carried out;

(4) and injecting the supernatant of the wastewater after catalytic oxidation treatment into the mineralized waste bioreactor from the top through a water distributor, and discharging the treated wastewater from the bottom of the mineralized waste bioreactor.

The device for realizing the method is characterized by comprising a chemical reactor, a pump, a peristaltic pump, an interval controller, a flowmeter, a pipeline, a water distributor and a mineralized garbage bioreactor, wherein a suction inlet of the pump is connected with a wastewater pump inlet pipe, and a discharge outlet of the pump is connected with the chemical reactor through the pipeline; the suction inlet of the peristaltic pump is connected with the chemical reactor through a pipeline, and the discharge outlet is connected with the water distributor of the mineralized waste bioreactor through a pipeline; the time controller is connected with the peristaltic pump in series.

The design principle of the invention is as follows: under the acidic condition of pH 2.0, adding proper amount of oxidant H according to the organic matter concentration of the organic waste water difficult to be biochemically degraded₂O₂Control of the oxidizing agent H₂O₂And catalyst Fe²⁺The molar ratio of the raw materials is 80: 1, and the difficultly biochemical organic matters in the wastewater are partially oxidized to ensure that the BOD of the wastewater is reduced₅With COD_CrRatio ofFrom less than 0.1 to 0.3. Inoculating domestic sewage to the mineralized refuse bioreactor, regulating the pH value of the wastewater treated by catalytic oxidation to be approximately 7.0, and injecting the wastewater into a water distributor of the mineralized refuse bioreactor by using a peristaltic pump so as to uniformly add the wastewater into the reactor. According to the properties of the organic wastewater difficult to biodegrade and the concentration of organic matters, the water inlet load and the retention time are adjusted to ensure that the COD of the effluent of the reactor_CrLess than or equal to 100mg/L and reaches the discharge standard.

The mechanism of the invention for the catalytic oxidation of the hardly biochemically degradable organic wastewater on the hardly biochemically degradable organic matter in the partially oxidized wastewater is as follows:

generation of mono-and hydroxyl radical OH

(1)

At the same time

(2)

(3)

(4)

(5)

Second, partial oxidation of organic matter

(6)

(7)

(8)

The invention has scientific design, reasonable structure, low treatment costand good treatment effect. After the treatment by the method, the raw materials are treated by the method,COD of wastewater_CrCan be reduced to 100mg/L and reaches the emission standard.

Drawings

FIG. 1 is a diagram of a reaction apparatus

The method and apparatus of the present invention are further illustrated by the following examples.

As shown in fig. 1, the apparatus for implementing the method of the present invention includes: the device comprises a pump 1, a chemical reactor 2, a sludge discharge pipe 3, a peristaltic pump 4, a time controller 5, a flowmeter 6, a pipeline 7, a water distributor 8 and a mineralized waste bioreactor 10. A suction inlet of the pump 1 is connected with a wastewater pump water inlet pipe, a discharge outlet is connected with the chemical reactor 2 through a pipeline, and sludge generated in the catalytic oxidation process is discharged through a sludge discharge pipe 3 of the chemical reactor 2; the suction inlet of the peristaltic pump 4 is connected with the chemical reactor 2 through a pipeline, and the discharge outlet is connected with the water distributor 8 of the mineralized refuse bioreactor 10 through a pipeline 5; the time controller 5 and the peristaltic pump 4 are connected in series. The mineralized refuse bioreactor 10 has a cylindrical packed tower, a water distributor 8 at the top of the packed tower, mineralized refuse filler 9 at the upper part of the packed tower, a rubble layer 12 at the lower part of the packed tower, and a sieve plate 11 separating the two parts, and the treated wastewater is discharged through an outlet pipeline 13. The chemical reactor 2 is a batch reactor.

The packed tower of the mineralized refuse bioreactor 10 is cylindrical, the height of the packed tower is 100cm, and the inner diameter of the packed tower is 50 cm. The mineralized waste bioreactor 10 comprises a water distributor 8, a mineralized waste filler layer 9, a sieve plate 11 and a crushed stone layer 12 from top to bottom. The particle size of the mineralized refuse filler is less than 1cm, and the height of the mineralized refuse layer is 90 cm. The height of the crushed stone layer is 8cm, wherein the diameter of the upper crushed stone is about 1cm, the height of the upper crushed stone layer is 3cm, and the diameter of the lower crushed stone layer is about 2cm, and the height of the lower crushed stone layer is 5 cm. The outlet 13 is arranged at the lowest end of the mineralized waste bioreactor 10.

An embodiment of the treatment of the ion exchange resin regeneration wastewater of a power plant. The ion exchange resin regeneration wastewater of the power plant desalting system has the daily output of hundreds of tons and COD_CrIs 200-300 mg/L. Its COD_CrAlthough not high, the content of the water is high in COD_CrAnd (3) humus, fulvic acid and other difficultly-biochemically-degraded high-molecular compounds which cannot be oxidized by potassium dichromate in the determination process. Therefore, the common wastewater treatment methods such as flocculation, conventional chemical oxidation and biochemical methods are difficult to achieve. Therefore, the method of the present embodiment using the combined chemical oxidation and biological treatment and the apparatus set up for the method as described above 1, the wastewater is pumped into the chemical reactor 2, the pH value of the wastewater is adjusted to 2.0, 8ml 30% hydrogen peroxide and a certain amount of ferrous sulfate are added to each liter of wastewater, and the oxidant H is controlled₂O₂And catalyst Fe²⁺The molar ratio of (A) to (B) is 80: 1. 2. After 4 hours of reaction, the pH value was adjusted to about 7.0 to complete the precipitation of sludge in the wastewater. 3. And (3) simultaneously with the

steps

1 and 2, biologically inoculating domestic sewage to the mineralized refuse bioreactor 10 until the quality of the effluent is stable. 4. Will pass through Fenton reagent(H₂O₂/Fe²⁺) The supernatant of the wastewater after the catalytic oxidation pretreatment is pumped into a mineralized waste bioreactor 10 by a peristaltic pump 4 through a water distributor 8, and the flow rate of inlet water is controlled, so that no water is accumulated on the upper layer of mineralized waste in the mineralized waste bioreactor. And after water is fed, discharging sludge at the bottom of the chemical reactor through a sludge discharge pipe. The treated effluent is discharged from an outlet 13 at the bottom of the reactor, thereby finishing the combined treatment of the catalytic oxidation of the ion exchange resin regeneration wastewater of the power plant and the mineralized garbage bioreactor. After the treatment by the method, the COD of the effluent_CrThe concentration is reduced to be less than 100mg/L, the pH value is 6.5-7.5, and the wastewater discharge standard of a power plant is met. Compared with the Fenton reagent single treatment, the method can save the cost by 80 percent, and the effluent quality is superior to the Fenton reagent single treatment.

Claims

1. A method for treating refractory organic wastewater by combining catalytic oxidation and biochemistry is characterized by comprising the following steps:

2. The method of claim 1, wherein: when the wastewater to be treated is treated by catalytic oxidation, the molar ratio of the added oxidant to the catalyst is 80: 1.

3. The device for implementing the method of claim 1, characterized in that the device consists of a pump (1), a chemical reactor (2), a sludge discharge pipe (3), a peristaltic pump (4), a time controller (5), a flowmeter (6), a pipeline (7), a water distributor (8) and a mineralized waste biological reactor (10); a suction inlet of the pump (1) is connected with a wastewater pump water inlet pipe, and a discharge outlet is connected with the chemical reactor (2) through a pipeline; a suction inlet of the peristaltic pump (4) is connected into the chemical reactor (2) through a pipeline, and a discharge outlet is connected into a water distributor (8) of the mineralized waste bioreactor (10) through a pipeline (7); the time controller (5) is connected with the peristaltic pump (4) in series.

4. The device according to claim 3, characterized in that the packed tower of the mineralized waste bioreactor (10) is cylindrical, the top of the packed tower is provided with the water distributor (8), the upper part of the packed tower is provided with the mineralized waste packing (9), the lower part of thepacked tower is provided with the gravel layer (12), the mineralized waste packing and the gravel layer are separated by a sieve plate (11), and the treated waste water is discharged through a water outlet pipeline (13).

5. The apparatus of claim 3, wherein: the chemical reactor (2) is a batch reactor, and the bottom of the reactor is provided with a sludge discharge pipe (3).

6. The apparatus of claim 3, wherein: the mineralized refuse filler (9) is mineralized refuse with the diameter smaller than 1cm, and the height of the mineralized refuse layer is 90 cm.

7. The apparatus according to claim 3 or 4, wherein: the gravel layer (12) with the height of 8cm is arranged at the lower part of the packed tower, wherein the diameter of the gravel with the height of 3cm at the upper part is 1cm, and the diameter of the gravel with the height of 5cm at the lower part is 2 cm.