WO2009094904A1

WO2009094904A1 - A method for treating high cod wastewater

Info

Publication number: WO2009094904A1
Application number: PCT/CN2009/000108
Authority: WO
Inventors: Dawei Zhang
Original assignee: Dawei Zhang
Priority date: 2008-01-24
Filing date: 2009-01-23
Publication date: 2009-08-06
Also published as: CN101492221A

Abstract

A method for treating high COD wastewater is provided, which comprises treating the wastewater in an anaerobic tank (5), and adsorbing pollutants from an anaerobic effluent in an active coke tank (8), collecting the biogas (10) produced by the anaerobic treatment to a storage closet (11), and feeding the biogas (10) to an active coke regeneration device (13) as a fuel for regenerating the saturated-active coke.

Description

髙 COD wastewater treatment method

The invention belongs to the technical field of wastewater treatment, and in particular relates to a method for treating high COD waste water by using anaerobic and active coke. Background technique

In environmental protection work, COD (Chemical Oxygen Demand) is used as an indicator to measure the amount of organic matter in water. At present, the common methods for treating high COD wastewater are anaerobic method and active coke filtration adsorption method.

The anaerobic treatment of high COD wastewater has a small footprint, low investment, and low processing cost. The disadvantage of the anaerobic method is that the treated water COD, chromaticity and other indicators cannot meet the discharge standard, and the anaerobic treatment process per 1 kg COD anaerobic treatment produces 0.3m ^³ -0.5m ³ biogas, as biogas generated enough economic lot, can not be achieved recycling commonly used method flaring process, that is a waste of energy and air pollution.

The wastewater is treated by activated coke filtration adsorption method. The treated water COD can reach 50mg/l or less, and the chroma can reach 5 times (dilution factor) below, which can fully meet the environmental emission standards. The disadvantage of the activated coke filtration adsorption method is that the treatment cost is high, and the main reason for the high treatment cost is that in the process of treating wastewater, the regeneration of each ton of saturated activated coke needs to consume 1.7-1.9 million kcal of heat, equivalent to about 243-271 kg of standard coal. Therefore, the energy cost of saturated activated coke regeneration accounts for 70-80% of the total cost of wastewater treatment by activated coke filtration. Summary of the invention

It is an object of the present invention to provide a COD wastewater treatment method that overcomes the deficiencies found in the prior art. In order to achieve the above object, the COD wastewater treatment method provided by the present invention is characterized in that the wastewater is subjected to anaerobic treatment, then subjected to active coke adsorption treatment, and biogas generated during anaerobic treatment is collected.

The method, wherein the wastewater is wastewater treated by a sedimentation tank.

The method, wherein the wastewater is wastewater treated by a regulating tank.

The invention combines two methods of anaerobic and active coke adsorption to treat high COD wastewater, that is, the active coke filtration adsorption deep treatment overcomes the defect that the water quality after the anaerobic treatment method fails to meet the discharge standard, and at the same time, the anaerobic treatment The biogas produced in the process is used as an energy source for the regeneration of saturated activated coke in the active coke filtration adsorption method, which can not only reduce the regeneration cost of the saturated activated coke, but also reduce the cost of the activated coke filtration adsorption process, and can save the cost. Energy, the above methods have not been reported so far. DRAWINGS

Figure 1 is a schematic flow chart of the present invention.

Marked in the figure: 1- Wastewater, 2-precipitation tank, 3-regulation tank, 4-water pump, 5-anaerobic reactor, 6-sink, 7-water pump, 8-active coke treatment unit, 9-clearing tank, 10-biogas, 11-biogas storage cabinet, 12-saturated activated coke, 13-active coke regeneration device. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the technical solutions of the present invention will be further specifically described by way of embodiments and with reference to the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar parts. The description of the embodiments of the present invention is intended to be illustrative of the present invention, and is not to be construed as limiting.

It should be noted that the technical conditions and equipment used in the two methods of anaerobic treatment and active coke adsorption in the present invention are well-known techniques, and the precipitation and the technical conditions and equipment used for regulating the water quality before the anaerobic treatment are also Known technology. The novelty and inventive concept of the present invention consists in combining two well-known techniques, anaerobic treatment and active coke adsorption treatment, and using biogas generated during anaerobic treatment as a fuel for regenerating saturated coke.

Specifically, the technical solution of the present invention is: (1) First, the wastewater is pretreated by an anaerobic method to convert most of the organic matter in the wastewater into biogas; (2) the water after the anaerobic treatment is used. The active coke filtration adsorption method is deeply treated to make the treated water quality meet the environmental emission standard or the enterprise water reuse standard; (3) The biogas generated in the anaerobic treatment process is used as the energy source for the saturated activated coke regeneration in the active coke filtration adsorption method.

Referring to Fig. 1, the wastewater 1 of the present invention enters the sedimentation tank 2, and the water after the precipitation treatment flows to the adjustment tank 3; the water in the adjustment tank 3 is sent to the anaerobic reaction device 5 by the water pump 4, in the anaerobic reaction device 5 Under the action of acid-producing bacteria and methanogens in the anaerobic reaction device 5, most of the biodegradable substances in the wastewater are oxidized to synthesize the biogas 10, and the water treated by the anaerobic reaction device 5 flows into the collecting pool. 6.

The wastewater in the collecting tank 6 is sent to the active coke processing device 8 by the water pump 7, and the water treated by the active coke treating device 8 flows into the clear water tank 9.

The active coke of the invention is made of anthracite, lean coal, lean coal, coking coal, fat coal, gas coal, long flame coal, lignite, semi-coke, coke or basket carbon, and is dried, retorted, carbonized and activated. , iodine adsorption value is 400mg / g ~ 800mg/go

The wastewater 1 is subjected to an anaerobic reactor 5 pretreatment and an active coke treatment unit. After deep treatment, the water quality fully meets the environmental emission standards.

The activated coke in the active coke processing device 8 becomes saturated active coke after being used for a certain period of time, and it is necessary to transport the saturated active coke 12 to the active coke regeneration device 13 for regeneration.

The invention collects the biogas 10 generated by the anaerobic reaction device 5 into the biogas storage cabinet 11, and the biogas storage cabinet 11 is a well-known device; the biogas 10 is discharged under the pressure of the biogas storage cabinet 11, and is transported to the activated coke through the pipeline. The device 13 serves as an energy source required for the active coke regeneration device 13 to operate.

The anaerobic reaction apparatus 5 employed in the present invention is a well-known apparatus and may be a UASB anaerobic reactor, an anaerobic reaction tank (Patent No.: CN97227787.0, Bulletin No. CN2309334) or / and an IC anaerobic reactor.

The active coke processing apparatus 8 employed in the present invention may be an activated coke adsorption bed (Patent No.: ZL 2006 2 0022884.1) or / and an active coke adsorption tank (Patent No.: ZL 2006 2 0022883.7). An ideal apparatus is an active coke adsorption tank provided by the patent number ZL 2006 2 0022883.7.

Among them, the apparatus for treating active coke is not strictly limited as long as it can satisfy the regeneration of activated coke by using biogas as a fuel. The present invention specifically recommends a device for regenerating a saturated activated coke according to the present invention. The detailed structure and working principle of the device can be found in the active semi-coke filter adsorbent processing apparatus disclosed in Patent Application No. 200710062831.1. In order to assist the person skilled in the art to further understand the present invention, a brief description of the apparatus will be given below.

The active semi-coke filter adsorption material processing device comprises a feeding bin, a screw feeder, a gas collecting device, a roller, a supporting roller ring, a transmission ring gear, a heating chamber wall, a reducer, a frequency conversion motor, a heating chamber, and a smoke exhaust port. , low-pressure gas burner, temperature measuring device, turning plate, discharging device, small roller, steam input pipe, observation hole, feeding temperature measuring device, discharge temperature measuring device, sealing device composition, combustion air fan, dust removal device, It consists of residual hot water jacket, induced draft fan, gas discharge machine and unit casing.

The roller making material of the active semi-coke filter adsorption material processing equipment is made of heat-resistant stainless steel, can withstand the high temperature of the unit during operation, and can resist general acid-base salt corrosion. The drum has a diameter of 600 mm to 2,000 mm and a length of 18,000 to 28,000 mm.

A sealing device is installed at a portion of the drum that is in contact with the heating chamber, and the sealing device is of a labyrinth or a steam type. Each side of the drum is provided with a small roller of 1 meter length, and the inner wall of the drum is provided with a spoon-shaped turning plate. The material of the material is the same as that of the drum. The inner wall of the drum is in direct contact with the material, and the upper and lower materials are alternately heated and heated uniformly. The hot gas generated in the drying and retorting stage of the material is collected by the gas collecting device at the front end of the drum and sent to the low-pressure gas burner for combustion. Object After the activation section is discharged, the cooling section is taken in, and it is naturally cooled until it is discharged. The roller has one supporting roller ring from the front and rear ends, and the outer wall of the roller is inlaid with the transmission gear ring, which is driven by the reducer and the variable frequency motor. The drum design speed is 0.5~1.5r/min, and the frequency conversion stepless speed regulation. The drum is mounted at an angle of 2°. In the middle of the unit is a heating chamber, which externally heats the outer wall of the drum. A burner is mounted on both side walls of the heating chamber, and the combustion blower provides air required for combustion. The burner is located at the lower portion of the drum to prevent the flame from being blown directly into contact with the drum. The burners are set up according to the temperature curve by 10~16, which are arranged on the two side walls of the heating chamber. The temperature of each section of the heating chamber is controlled by adjusting the air supply volume of each burner to ensure the preparation process of the active semi-coke filter adsorbent. Temperature, warming time and constant temperature time.

The lining of the heating chamber wall is a combination of lightweight high-aluminum brick and high-aluminum fiber. The top of the heating chamber is a high-alumina poly-light brick flat ceiling. It is easy to disassemble when the drum is repaired. The lightweight insulation material between the heating chamber side wall and the unit casing is , the amount of heat dissipation is small, and the temperature rises quickly. The unit casing is made of steel and steel.

The flue gas in the heating chamber of the active semi-coke filter adsorption processing equipment is discharged from the exhaust port installed at the top of the unit, the exhaust port is connected with the residual hot water jacket and the induced draft fan, the induced draft fan adopts frequency conversion speed regulation, and the residual hot water jacket is used for recycling smoke. Heat in the gas, lower the temperature of the flue gas, and heat the steam boiler to replenish water.

A plurality of temperature measuring devices are installed on both sides of the heating chamber wall to detect the temperature of each temperature section, and a temperature measuring device is installed at the head and the tail of the unit to detect the feeding temperature and the discharging temperature. The unit is provided with a control cabinet and a control cabinet. Install 20 digital display meters, frequency conversion motor inverter and induced draft fan inverter and screw feeder inverter, power switch and low voltage electrical appliances.

The mixed gas such as hot gas generated during the processing of the material in the drum is collected by the gas collecting device at the front end of the drum, and is processed by the dust removing device, and then sent to the low-pressure gas burner of the unit for combustion. A sealing device is arranged between the gas collecting device and the drum, and the sealing device can be a labyrinth or a steam type.

The fuel required for the operation of the active semi-coke filter sorbent processing equipment uses the biogas produced during the operation of the anaerobic reactor 6 and the mixed gas produced during the operation of the activated semi-coke filter sorbent processing equipment.

The front end of the drum of the active semi-coke filter adsorption processing equipment is equipped with a screw feeder and a feeding bin, and the feeding speed of the screw feeder is adjusted by the frequency conversion controller. A discharge device is installed at the rear end of the drum, and an observation hole and a steam inlet pipe are provided at the end surface of the drum. A sealing device is arranged between the discharging device and the drum, and the sealing device can be a labyrinth or a steaming type. Example 1

The invention utilizes the invention to treat chemical pulping wastewater of papermaking enterprises.

The wastewater 1 enters the sedimentation tank 2, and the residence time of the wastewater 1 in the sedimentation tank is 2-3 hours, and the water after the precipitation treatment flows to the adjustment tank 3; in the adjustment tank 3, NaOH or HC1 is added to adjust the appropriate reaction pH. Value and investment Add N, P nutrient salts. Here, the complex water-insoluble matrix in the wastewater is converted by the extracellular enzyme secreted by the microorganism into a smaller, water-soluble matrix, ie a hydrolysis reaction. The water in the conditioning tank 3 is sent to the anaerobic reactor 5 by the water pump 4. Under the action of acid-producing bacteria and methanogens in the anaerobic reaction device 5, most of the biodegradable substances in the wastewater are oxidized to synthesize the biogas 10.

The operating parameters of this embodiment:

1) Process papermaking wastewater of 5,000 tons per day. Wastewater entering sedimentation tank 2 lCOD 6,000mg/l;

2) The wastewater is treated by the anaerobic reactor 5 and then flows into the collecting tank. 6. The COD in the water is 1500mg/l, and the COD removal rate is over 75%.

3) The water in the catchment tank 6 is treated by the active coke treatment device 8 and then flows into the clear water pool. 9. The COD content in the water is 70mg/l, the turbidity is 5Ftu, and the chromaticity is 5 times, which meets the environmental emission standards and the standard of papermaking water;

4) The active coke processing device 8 discharges 16 tons of saturated activated coke 12 per day, and delivers the above-mentioned saturated active coke 12 to the active coke regeneration device 13 for regeneration. The activated coke regeneration device 13 requires 1.85 million calories per 1 ton of saturated active coke 12 Kcal, the total heat required to regenerate 16 tons of saturated activated coke 12 per day is: Q-185.5 kcal/ton xl6 tons = 29.68 million kcal;

5 during operation of the device 5) in the anaerobic reactor to produce biogas per day 9,460 Nm ³ 10, heat generation per 10 Nm ³ methane gas was 2,720Kcal / m ^3, 12 of the total heat 9,460Nm ³ biogas Wan 2,545 kcal. The remainder of the heat required to operate the activated coke regeneration unit 13 per day is provided by a combustible mixture of pyrolysis of organic matter in the drum during its operation.

While some embodiments of the present general inventive concept have been shown and described, it will be understood by those of ordinary skill in the art that the present invention may be modified without departing from the principles and spirit of the present general inventive concept. The scope is defined by the claims and their equivalents.

Claims

Rights request

1. A method for treating COD wastewater, which is subjected to anaerobic treatment, and then subjected to active coke filtration adsorption treatment.

2. The method according to claim 1, wherein the biogas generated in the anaerobic treatment of the wastewater is collected and sent to the active coke regeneration device as an energy source required for active coke regeneration.