CN102285739A - BCMB (Buffering Circulating MediaBiological Bed) treatment method for high-concentration toxic organic waste water - Google Patents

Abstract

The invention relates to a method for treating high-concentration toxic organic waste water with a buffer type circulation carrier biological bed, belonging to the technical field of industrial waste water treatment. The wastewater is firstly pretreated, and then enters the buffered circulation carrier biological bed reactor for treatment to achieve efficient removal of high-concentration toxic organic matter. Finally, the wastewater enters the sedimentation tank for mud-water separation and discharges up to the standard. The buffered circulation carrier biological bed reactor increases the biomass and biological activity in the reactor, promotes the mass transfer in the reactor, and improves the efficiency of high The buffering capacity of concentrated toxic organic wastewater quality fluctuations improves the reactor processing load and impact resistance. The invention treats high-concentration toxic organic waste water, and has the advantages of high treatment load, small footprint, strong impact resistance, stable effluent quality, and the like.

Description

A method for treating high-concentration toxic organic wastewater with a buffered circulation carrier biological bed

technical field

The invention relates to a method for treating high-concentration toxic organic wastewater with a buffering circulatory carrier biological bed (Buffering Circulating MediaBiological bed, BCMB), in particular to a novel wastewater biological treatment method and a reactor, which treats high-concentration toxic organic wastewater. Organic wastewater has the advantages of strong biological activity, high treatment load, small footprint, strong impact resistance, and stable effluent quality.

Background technique

High-concentration toxic organic wastewater is a common type of industrial wastewater, and it is a stream of wastewater that is difficult to treat in petrochemical, coal chemical, paper, pharmaceutical, printing and dyeing industries. Since the wastewater contains a high concentration of toxic organic substances, if the traditional biological treatment process is adopted, it has problems such as low treatment load, long residence time, large floor area, poor impact resistance, and unstable effluent quality. The treatment of high-concentration toxic organic wastewater has become a bottleneck factor restricting the sustainable development of key industries in our country.

At present, the treatment methods of high-concentration toxic organic wastewater mainly include physical and chemical methods and biological methods. Common physical and chemical methods include wet oxidation, catalytic wet oxidation, incineration, extraction, and adsorption. Patent CN 86108854A proposes a method for removing toxic organic substances from a dilute aqueous solution of toxic organic substances. The invention adopts an adsorption-regeneration method to realize the removal and degradation of toxic organic pollutants. Physicochemical treatment of high-concentration toxic organic wastewater has the advantages of high treatment load and small footprint, but there are problems such as complex equipment, high requirements for operation and management, large energy consumption, and high operating costs. The biological treatment technologies for high-concentration toxic organic wastewater include activated sludge method and biofilm method, and the anaerobic-aerobic process is currently the most widely used biological treatment technology for toxic organic wastewater. Compared with the physical and chemical treatment technology, the biological method has the advantages of simple equipment and low operating cost. Patent CN 201406362Y proposes a solid-loaded aerobic-anaerobic device for degrading toxic organic matter, which has the advantages of simple structure and low cost. However, the current anaerobic-aerobic treatment process generally has problems such as low treatment load, poor impact resistance, and easy loss of microorganisms.

Based on the prior art, the present invention aims at the problems of low processing load, poor impact resistance and easy loss of microorganisms in the biological treatment of high-concentration toxic organic wastewater. Immobilization technology increases the number of microorganisms in the reactor, enhances their degradation ability and activity, and strengthens the mass transfer of pollutants, oxygen and intermediate products, thus realizing the high-load and impact-resistant treatment of high-concentration toxic organic wastewater.

Contents of the invention

The purpose of the present invention is to overcome the problems of low treatment load, large floor area and poor impact resistance of the existing high-concentration toxic organic wastewater treatment method, and provide a more effective wastewater treatment method. The invention for treating high-concentration toxic organic wastewater has the advantages of strong biological activity, high treatment load, small footprint, strong impact resistance, stable effluent quality, and the like.

In order to achieve the above object, the method for processing high-concentration toxic organic wastewater provided by the invention, the main steps are as follows:

1. Wastewater pretreatment: According to the water quality characteristics of the wastewater, the pollutants that interfere with the subsequent biological treatment, such as suspended particles and oils in the wastewater, are removed by means of precipitation, oil separation, air flotation, cooling, neutralization, and addition of nutrient salts. Make the temperature, pH and nutrient conditions of wastewater suitable for subsequent biological treatment;

2. The pretreated wastewater enters the buffer type circulation carrier biological bed for treatment, so as to realize the efficient removal of high-concentration toxic organic matter. The buffered circulation carrier biological bed is characterized by:

a. The reactor is divided into several compartments, and the compartments are connected in series. According to the characteristics of wastewater and treatment requirements, the number of compartments ranges from 3 to 10. The effective volume of the first compartment is 1 to 2 times the effective volume of other compartments. According to the requirements of wastewater treatment, each compartment can adopt anaerobic, anoxic, facultative and aerobic operation modes respectively. By forming microbial populations with different functions and characteristics in different compartments, the efficient degradation of toxic organic substances can be achieved; when wastewater When there is a requirement for denitrification, the water inlet method can be used in stages to make full use of the self-owned carbon source in the wastewater, reduce the reflux of the mixed solution, and reduce energy consumption. The last compartment is a sedimentation unit, and the suspended sludge concentrated by sedimentation is returned to the previous compartment under the action of gravity, thereby improving the pollutant removal capacity at the end of the reactor.

b. The reactor is filled with a suspended porous high-efficiency biological carrier, and the volume of the carrier accounts for 20% to 60% of the effective volume of the biological bed.

c. The size of the biological carrier used in the reactor is 8-20mm, and the size of the aerobic filler is preferably 8-10mm; the porosity is more than 90%, and the main body is organic polymers such as polyurethane and polyurethane. The carrier passes through the surface Group modification and combination with strong adsorption materials have a positive charge and strong adsorption capacity for toxic organic substances, which is conducive to the attachment of microorganisms (usually negatively charged), improving the buffering capacity of the reactor for toxic organic substances; after the biological carrier is attached to the biofilm, Its density is slightly higher than that of water, and it is easy to suspend and fluidize in the reactor.

d. Through the layout of the aeration head and diversion plate and the slope design of the biological carrier screen in the reactor, the specific gravity of the biological carrier after the biofilm is attached is slightly greater than that of water, and through aeration, stirring, etc. With low energy consumption, the carrier circulation flow can be realized, and the mass transfer can be accelerated.

3. The wastewater treated by the buffered circulation carrier biological bed enters the sedimentation tank for mud-water separation, the wastewater treated by the sedimentation is discharged up to the standard, and the sludge generated in the sedimentation tank is further treated.

The core of the present invention is to increase the number, degradation ability and activity of microorganisms in the reactor through the reactor shock resistance design, mass transfer optimization control and high-efficiency microorganism immobilization technology in the wastewater biological treatment reactor, and strengthen the pollution of pollutants, oxygen and intermediates. The mass transfer of the product realizes the high-load and impact-resistant treatment of high-concentration toxic organic wastewater.

The reactor is divided into multiple compartments connected in series to form a multi-stage buffer reactor configuration and improve the impact resistance of the reactor. At the same time, each subdivision adopts different operating conditions such as aeration volume according to the treatment of wastewater, and adopts anaerobic, anoxic, facultative and aerobic operating modes respectively to form different microbial population structures under different pollution loads. Improve the degradation ability of toxic organic substances. In the first subdivision, under anaerobic, anoxic or facultative operating conditions, the transformation of toxic organic substances in wastewater can be achieved and the toxicity of wastewater can be reduced. Subsequent compartments further degrade residual organic matter in wastewater under aerobic or anoxic conditions. The last cell is the sedimentation unit, and the suspended sludge that has been concentrated by sedimentation flows back to the previous cell under the action of gravity, thus forming a complex microbial system at the end of the reactor, which has the advantages of the activated sludge method and the biofilm method, and strengthens the reaction. The pollutant removal ability at the end of the device improves the stability of the effluent water quality.

The bio-carriers of the reactor are positively modified by surface groups and combined with strong adsorption materials to promote the growth and retention of slow-growing pollutant-degrading bacteria in the reactor, so that there is no sludge return or low sludge return. Guaranteed high biomass in the reactor. At the same time, due to the combination of the biological carrier with strong adsorption materials such as activated carbon in the preparation process, it shows a strong adsorption capacity for toxic organic substances, and can play a significant buffer role when the concentration of pollutants in toxic organic wastewater fluctuates sharply, preventing wastewater from being too toxic. Microbial activity decline and biofilm shedding caused by high temperature can improve the stability of system operation and effluent water quality.

Through the fluidized design in the reactor, the circulating flow of wastewater and biological carriers can be realized at low energy consumption, the mass transfer of pollutants, oxygen and intermediate products in the reactor can be improved, and the local accumulation of toxic pollutants and intermediate products can be prevented. Adverse effects on microorganisms, improve microbial degradation activity, reduce the restriction of mass transfer on the degradation process of pollutants, and improve the efficiency of mass transfer and utilization of oxygen. The biological carrier in the reactor is in a state of circulating flow without clogging, which avoids the problem of short flow in traditional bioreactors, especially anaerobic reactors, and improves the volume utilization efficiency of the reactor.

In summary, the advantages of the present invention are:

1) High processing load and short residence time: the reactor has high biomass, good mass transfer performance, and high microbial degradation activity, so that the reactor can achieve high processing load, short residence time, small footprint, and low infrastructure investment Province.

2) Strong impact load resistance and stable effluent quality: the multi-stage buffer configuration of the reactor and the application of strong adsorption biological carriers, coupled with the enhanced degradation of the end unit of the reactor, make the pollution in high-concentration toxic organic wastewater The pollutants are effectively buffered and multi-stage removed, reducing the concentration of toxic pollutants directly contacted by microorganisms, thereby strengthening the tolerance of the reactor to the water quality fluctuation of toxic organic wastewater, the reactor effluent water quality is stable, and the operation and management are simple.

3) Low energy consumption and low operating cost: the reactor has good mass transfer performance, high microbial activity, and high oxygen mass transfer and utilization efficiency. At the same time, the density of the biological carrier material is similar to that of water after the biofilm is attached, and the suspension and circulation flow can be realized with low energy input. Therefore, the operating cost of the reactor is lower.

Description of drawings

Fig. 1 is a structural schematic diagram of a buffered circulation carrier biological bed of the present invention. In the figure: 1 is the reactor pool body, 2 is the water inlet area, 3 is the suspended biological carrier partition, 4 is the reactor partition, 5 is the aeration pipe, 6 is the suspended biological carrier, 7 is the flow hole, 8 9 is the sedimentation area, 10 is the water inlet pipe, and 11 is the water outlet pipe.

Detailed ways

The buffer type circulating carrier bio-bed reactor proposed by the present invention is shown in Fig. 1, and aeration equipment is arranged inside, and high-efficiency microorganism immobilized suspension carriers are installed in the fluidized bed.

Some specific embodiments based on the present invention are given below, but the content protected by the patent of the present invention is not limited to the embodiments.

Embodiment 1: Treatment of high-concentration oil refining wastewater containing phenol

1) First, neutralize and pre-treat the wastewater to remove petroleum substances in the wastewater, then cool and add nutrient salts to make the temperature, pH and nutritional conditions of the wastewater suitable for subsequent biological treatment;

2) The pretreated wastewater enters the buffered circulation carrier biological bed reactor for treatment. The reactor is divided into 4 grids, the first grid is twice the effective volume of the subsequent grids, and the biological carrier is positively modified on the surface and combined with The cubic polyurethane suspended porous material with a side length of 10mm combined with activated carbon materials has a filling ratio of 35%. Each compartment uses air aeration to fluidize wastewater and biological carriers. The first compartment operates under facultative oxygen conditions. , the subsequent compartments run under aerobic conditions. The residence time of wastewater in the reactor is 60h. When the total phenol concentration in the influent is 5000mg/L and the COD is 14000mg/L, the total phenol in the effluent of the buffered circulation carrier biological bed is below 30mg/L, the COD is below 2000mg/L, and the total phenol removal rate is over 99%. .

Embodiment 2: Treatment of high-concentration wastewater containing mixed phenols

1) First, neutralize and pre-treat the wastewater to remove petroleum substances in the wastewater, and then add nutrient salts to make the temperature, pH and nutritional conditions of the wastewater suitable for subsequent biological treatment;

2) The pretreated wastewater enters the buffered circulation carrier biological bed reactor for treatment. The reactor is divided into 4 grids, and the effective volume of the 4 grids is the same. The porous material is suspended, the filling ratio is 40%, and each compartment adopts air aeration to realize the fluidization of wastewater and biological carriers, and operates under aerobic conditions. The residence time of wastewater in the reactor is 8h. When the influent phenol concentration is 200mg/L, the m-cresol concentration is 200mg/L, the o-cresol concentration is 100mg/L, and the COD is 1200mg/L, the total phenol in the effluent of the buffered circulation carrier biological bed reaches 2mg/L Below, the COD is below 60mg/L, and the total phenol removal rate is above 99%.

Embodiment 3: Treatment of high-concentration acrylate production wastewater

1) First, neutralize and cool the wastewater for pretreatment, and then add nutrients to make the temperature, pH and nutritional conditions of the wastewater suitable for subsequent biological treatment;

2) The pretreated wastewater enters the buffered circulation carrier bio-bed reactor for treatment. The reactor is divided into 3 grids, and the effective volume of the 3 grids is the same. Urethane porous filler, with a filling ratio of 30%, each cell uses air aeration to fluidize wastewater and biological carriers, and operates under aerobic conditions. The residence time of wastewater in the reactor is 30h. When the influent sodium acrylate concentration is 8300mg/L and COD is 10000mg/L, the effluent sodium acrylate concentration of the buffered circulation carrier biological bed is below the detection limit, the COD is below 360mg/L, and the COD removal rate is over 95%. .

Claims (6)

1. the method for a buffer-type circulation carrier organism bed processing high density poisonous organic wastewater is characterized in that this method comprises the steps:

A. waste water at first carries out pre-treatment, makes the water quality characteristic of waste water be fit to subsequent biological treatment;

B. pretreated waste water enters buffer-type circulation carrier organism bed bioreactor and handles, and realizes the efficient removal of high density toxic organic compound;

C. the waste water of handling through buffer-type circulation carrier organism bed enters and carries out mud-water separation and qualified discharge in the settling tank, and the mud that settling tank produces is further processed.

2. a kind of buffer-type circulation carrier organism bed according to claim 1 is handled the method for high density poisonous organic wastewater, it is characterized in that the water quality characteristic according to waste water is the pollutent of carrying out a biological disposal upon by interfere with subsequent such as the suspended particulate in pretreatment processs such as precipitation, oil removal, air supporting, cooling, neutralization, the interpolation nutritive salt removal waste water, oils, make the suitable subsequent biological treatment such as temperature, pH and nutritional condition of waste water simultaneously.

3. a kind of buffer-type circulation carrier organism bed according to claim 1 is handled the method for high density poisonous organic wastewater, it is characterized in that the circulation carrier organism bed bioreactor that adopts is divided into some lattices, it between each lattice series system, according to wastewater characteristics and processing requirements, lattice quantity is that 3～10 lattice do not wait.The useful volume of the 1st lattice is 1～2 times of other lattice useful volumes.According to the wastewater treatment requirement, each lattice can adopt anaerobism, anoxic respectively, hold concurrently oxygen and aerobic operation scheme.When wastewater treatment has the denitrogenation requirement, can adopt the segmental influent mode.Last lattice are precipitation unit, are back to last lattice through precipitating spissated suspended sludge under action of gravity, thereby improve the contaminant removal capacity of reactor end.

4. buffer-type circulation carrier organism bed bioreactor according to claim 3 is characterized in that filling in the reactor suspended porous high-performance bio carrier, and the volume of carrier accounts for 20%～60% of biological bed useful volume.

5. suspending porous biological carrier according to claim 4 is characterized in that carrier dimensions is 8～20mm, and aerobic filler size is that 8～10mm is preferable; Porosity is more than 90%, main body is organic high molecular polymers such as urethane, polyurethane, carrier modify through surface group and with combining of sorbing material by force, have positive charge and toxic organic compound is had strong adsorptive power, be beneficial to microorganic adhesion, can improve the surge capability of reactor toxic organic compound; Behind the bio-carrier attached biological film, its density is slightly larger than water, suspends easily and fluidisation in reactor.

6. buffer-type circulation carrier organism bed bioreactor according to claim 3, it is characterized in that the laying by aeration head and diaphragm, the gradient design of bio-carrier filter, make full use of the characteristic that attached biological film artifact carrier proportion is slightly larger than water, realize that under lower energy consumption carrier circulates, and quickens mass transfer.

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