CN104445592B - Aerobic Co-metabolism processes the method for brown coal upgrading waste water - Google Patents

Abstract

The invention discloses a method for aerobic co-metabolism treatment of lignite upgrading wastewater, which relates to a method for treatment of coal chemical wastewater. The invention solves the problem that the removal effect of the pollution components that cannot be directly used as microbial nutrients is not good or the number of microbial flora that can degrade such substances is small and the flora function is poor in the aerobic reactor. The main steps are: selecting lignite upgrading wastewater; selecting trehalose as the first co-metabolism substrate, and its dosage is regulated by an automatic dosing system. Use the returning sludge from the secondary settling tank of the urban sewage plant as the inoculation sludge, keep the hydraulic retention time of the aerobic reactor at 18-24 hours, and control the stable industrial and mining. The present invention uses trehalose as the first substrate, and the organic matter that cannot be used as the direct substrate of aerobic microorganisms can be degraded, or can strengthen the growth and reproduction of aerobic microorganisms using the substance as the substrate. After stable operation, the COD removal rate of aerobic treatment of lignite upgrading wastewater can reach more than 85%, and the total phenol removal rate can reach more than 80%.

Description

Aerobic co-metabolism method for treating lignite upgrading wastewater

technical field

The invention relates to a method for treating lignite upgrading wastewater, which belongs to the technical fields of municipal engineering, environmental engineering and chemical wastewater treatment.

Background technique

Lignite upgrading wastewater mainly comes from the high-temperature wastewater discharged from the leaching pretreatment section of the lignite upgrading process by leaching and evaporation. The lignite wastewater has a wide variety of components and a high concentration of pollutants, among which the main inorganic pollutants are: ammonia nitrogen, S ^2- , CN ^- ; there are 37 kinds of organic substances, including humic acid, phenols, long-chain alkanes, naphthalene, imidazole, Benzofuran, pyrazole, etc. Most of these components are toxic and harmful substances with high biological toxicity, which seriously threatens environmental safety. Therefore, how to treat lignite upgrading wastewater economically and efficiently is becoming increasingly important.

At present, most of the treatment methods for refractory industrial wastewater such as lignite upgrading wastewater at home and abroad are combined anaerobic and aerobic treatment. The function of anaerobic process is to improve the biodegradability of wastewater and reduce the load of subsequent treatment structures. main process. However, because some organic substances in lignite upgrading wastewater cannot be used as microbial nutrient substrates, or the types of microorganisms that can directly use this substance as nutrient substrates are limited, not only the effluent from the anaerobic reactor contains such pollutants, but also enters the aerobic environment. After the reactor, such substances still cannot be completely degraded, which leads to low efficiency of the biological treatment process of lignite upgrading wastewater and increases the difficulty and load of subsequent advanced treatment. Therefore, how to remove them in the aerobic reactor cannot be directly used as microbial nutrition. The key to the economical and effective treatment of lignite upgrading wastewater is to increase the number of microbial flora that can degrade such substances and to improve the function of the flora.

Contents of the invention

The purpose of the present invention is to provide a good method for removing polluting components that cannot directly serve as nutrients for aerobic microorganisms in an aerobic reactor or increasing the number of aerobic microbial flora that can degrade such substances and promoting the function of the flora. Oxygen co-metabolism method for treating lignite upgrading wastewater.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: the method for aerobic co-metabolism treatment of lignite upgrading wastewater according to the present invention comprises the following steps: 1. Selecting lignite upgrading wastewater, which is extracted from lignite After cooling and sedimentation in the intermediate sedimentation tank, the following process is used for treatment: adding demulsifier and flocculant, and the supernatant water after demulsification, coagulation and sedimentation treatment is lifted to an anaerobic reactor by a peristaltic pump for anaerobic hydrolysis Acid treatment. The effluent from the anaerobic reactor is waste water to be treated. The water quality is as follows: COD concentration 950~1200mg/L, BOD ₅ concentration 350~400mg/L, total phenol concentration 70~90mg/L, ammonia nitrogen concentration 55~70mg/L, total phosphorus concentration 3~5mg/L. ②Trehalose was selected as the first co-metabolism substrate, and it was prepared as a stock solution and stored in the trehalose dissolving pool. ③Transfer the untreated lignite upgrading wastewater to the aerobic reactor through the lift pump. The operating parameters of the reactor are: COD volume load is 0.95~1.6kgCOD/(m ³ ·d), hydraulic retention time is 18~24h, filler filling rate is 80%; As the inoculation sludge, the aerobic reactor was started by the inoculation cultivation method. The dosage of inoculated sludge is 4~6g/L; ⑤ Dosing trehalose into the aerobic reactor, the dosage is regulated by the automatic trehalose dosing system; The dosage of trehalose was used to run the reactor. The trehalose automatic dosing system in step ⑤ is composed of a trehalose dissolving tank, an on-site detection equipment COD online detector installed at the end of the anaerobic reactor, a computer equipped with a PLC controller, a solenoid valve, and a metering pump. The PLC automatic control system adopts a feedback control structure, the control parameter is the dosage of trehalose/COD concentration at the end of the anaerobic reactor, and the controlled variable is the dosage of trehalose. The COD online analyzer detects the COD concentration at the end of the anaerobic reactor, sends it to the data acquisition card of the computer, calculates the trehalose dosage/COD value, converts it into a digital signal, and inputs it into the PLC controller, and communicates with it The trehalose dosage/COD value is compared with the set value, and the PID algorithm is used for calculation, and the result is used as the output value to control the operation of the solenoid valve and the metering pump of the terminal execution equipment. In the automatic control system of trehalose dosage in step ⑤, the setting value of trehalose dosage/COD value is 0.5~1.0.

Invention principle and advantages

The present invention uses trehalose as the first substrate for aerobic co-metabolism treatment of lignite upgrading wastewater, so that the biological treatment effect of lignite upgrading wastewater is greatly improved, and a large number of aerobic substances suitable for treating lignite upgrading wastewater are produced. microbial populations. Using trehalose as the first substrate degrades the organic matter that cannot be used as the direct substrate of aerobic microorganisms, or strengthens the growth and reproduction of aerobic microorganisms based on this substance and promotes the function of their flora, improving the treatment efficiency. After stable operation, under the condition of aerobic hydraulic retention time of 18h and optimal trehalose dosage ratio, the COD removal rate of aerobic co-metabolism treatment of lignite upgrading wastewater can reach more than 85%, and the total phenol removal rate can reach 80~ 90%.

Description of drawings

Figure 1 is a schematic diagram of the structure of a biological contact oxidation reactor. Water inlet 1, lifting pump 2, soft packing 3, air diffusion plate 4, water outlet 5, gas flow meter 6, air compressor 7, trehalose solution 8, metering pump 9. Fig. 2 is a schematic diagram of the trehalose automatic dosing system.

detailed description

Specific implementation mode one: this implementation mode is the method for anaerobic co-metabolism treatment of lignite upgrading wastewater, which is specifically completed according to the following steps:

①Select lignite upgrading wastewater, which is collected from the lignite upgrading process, and after cooling and sedimentation in the intermediate sedimentation tank, the following process is used: adding demulsifier and flocculant, after demulsification, coagulation, and sedimentation treatment The final supernatant water is lifted to the anaerobic reactor by a peristaltic pump for anaerobic hydrolysis and acidification treatment, and the effluent from the anaerobic reactor is the lignite upgrading wastewater to be treated. The water quality is as follows: COD concentration 950~1200mg/L, BOD ₅ concentration 350~400mg/L, total phenol concentration 70~90mg/L, ammonia nitrogen concentration 55~70mg/L, total phosphorus concentration 3~5mg/L.

②Trehalose was selected as the first co-metabolism substrate, and it was prepared as a stock solution and stored in the trehalose dissolving pool.

③Transfer the untreated lignite upgrading wastewater to the aerobic reactor through the lift pump. The operating parameters of the reactor are: COD volume load is 0.95~1.6kgCOD/(m ³ ·d), hydraulic retention time is 18~24h, and filler filling rate is 80%;

④Using the return sludge from the secondary settling tank of the urban sewage treatment plant as the inoculation sludge, the aerobic reactor was started by the inoculation training method. The dosage of inoculated sludge is 4~6g/L;

⑤ Dosing trehalose into the aerobic reactor, the dosage is regulated by the trehalose automatic dosing system;

⑥ Control the stable operation of the mine, and run the reactor on the basis of the dosage of trehalose described in step ⑤.

The trehalose automatic dosing system in step ⑤ is composed of a trehalose dissolving tank, an on-site detection equipment COD online detector installed at the end of the anaerobic reactor, a computer equipped with a PLC controller, a solenoid valve, and a metering pump. The schematic diagram of the automatic control system is shown in Figure 2. The PLC automatic control system adopts a feedback control structure, the control parameter is the dosage of trehalose/COD concentration at the end of the anaerobic reactor, and the controlled variable is the dosage of trehalose. The COD online analyzer detects the COD concentration at the end of the anaerobic reactor, sends it to the data acquisition card of the computer, calculates the dosage of trehalose/COD value, and converts it into a digital signal, which is input to the PLC controller, and The trehalose dosage/COD value is compared with the set value, and the PID algorithm is used for calculation, and the result is used as the output value to control the operation of the solenoid valve and the metering pump of the terminal execution equipment. In the automatic control system of trehalose dosage in step ⑤, the setting value of trehalose dosage/COD value is 0.5~1.0.

The aerobic reactor operates stably under the condition of a hydraulic retention time of 18 hours. The COD removal rate of the aerobic treatment lignite upgrading wastewater can reach more than 85% under the condition of the optimal trehalose dosage ratio of 0.75~0.85, and the total phenol removal rate Reached more than 80%; compared with the blank test results, the COD and total phenol removal rates increased by more than 10% and 25% respectively under the condition of optimal trehalose dosage ratio. Therefore, adding the optimal amount of trehalose can improve the biological treatment effect of lignite upgrading wastewater.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that in step ③, the COD volume load of the aerobic reactor is 1.2 kgCOD/(m ³ ·d) or 1.5kgCOD/(m ³ ·d), The hydraulic retention time is 20h or 24h, and the others are the same as in the first embodiment.

Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that in step 4., the initial inoculation sludge dosage in the aerobic reactor is 5g/L, other and specific embodiment one or two same.

Embodiment 4: The difference between this embodiment and Embodiments 1 to 3 is that in step ⑤, the set value of trehalose dosage/COD value is 0.75~0.85.

Example:

Reactor: biological contact oxidation reactor, made of plexiglass, the structure is shown in Figure 1.

The water quality is as follows: COD concentration 950~1200mg/L, BOD ₅ concentration 350~400mg/L, total phenol concentration 70~90mg/L, ammonia nitrogen concentration 55~70mg/L, total phosphorus concentration 3~5mg/L.

Operating conditions: The operating parameters of the aerobic reactor are: COD volume load is 0.95~1.6kgCOD/(m ³ ·d), the hydraulic retention time is 18~24h, and the filler filling rate is 80%; the secondary sedimentation tank of the urban sewage treatment plant is used The return sludge is inoculation sludge, and the aerobic reactor is started by the inoculation training method. The initial sludge dosage is 5g/L; the setting value of trehalose dosage/COD value is 0.75~0.85.

Operation effect: After three to four months of stable operation under this implementation condition, the COD removal rate of aerobic co-metabolism treatment of lignite upgrading wastewater can reach more than 85% when the optimal trehalose dosage ratio is 0.75~0.85, and the total The phenol removal rate reached over 80%. Compared with the blank test results, the COD and total phenol removal rates increased by more than 10% and 25% respectively under the condition of the optimal trehalose dosage ratio.

Claims (4)

1. the method that an Aerobic Co-metabolism processes brown coal upgrading waste water, it is characterised in that described method comprises the steps:

1. brown coal upgrading waste water is selected, this brown coal upgrading waste water is to collect from brown coal process for upgrading, following PROCESS FOR TREATMENT is used: add demulsifier, flocculant after intermediate sedimentation pond cooling precipitation, supernatant water after breakdown of emulsion, coagulation, precipitation process is promoted to anaerobic reactor through peristaltic pump and carries out anaerobic hydrolysis-acidification process, and anaerobic reactor water outlet is pending brown coal upgrading waste water；Water quality is as follows: COD concentration 950 ~ 1200mg/L, BOD₅Concentration 350 ~ 400mg/L, total phenols concentration 70 ~ 90mg/L, ammonia nitrogen concentration 55 ~ 70mg/L, total phosphorus concentration 3 ~ 5mg/L；2. select trehalose as Co metabolism the first substrate, be configured to stock solution and be stored in that trehalose is molten joins in pond；Pending brown coal upgrading waste water is delivered to aerobic reactor by the most boosted pump；This reactor operational factor is: COD volumetric loading is 0.95 ~ 1.6kgCOD/ (m³D), hydraulic detention time is 18 ~ 24h, and media-filling rate is 80%；4. using municipal sewage plant's second pond returned sludge as seed sludge, use inoculation training to tame and docile method, start aerobic reactor；Seed sludge dosage is 4 ~ 6g/L；5. adding trehalose in aerobic reactor, its dosage is regulated and controled by trehalose automatic Dosing System；6. control stable operating condition, on the basis of the trehalose dosage that employing step is 5. described, run reactor；Step 5. in trehalose automatic Dosing System by trehalose molten join pond, be installed on anaerobic reactor end field detecting device COD on-line determination instrument, the computer of PLC is installed, electromagnetic valve, dosing pump form；PLC uses feedback control structure, and controlling parameter is trehalose dosage/anaerobic reactor end COD concentration, and controlled variable is trehalose dosage；The COD concentration of COD on-line determination instrument detection anaerobic reactor end, it is transported to the data collecting card of computer, calculate trehalose dosage/anaerobic device reactor end COD concentration, and convert thereof into digital signal, input to PLC, compare with the setting value of trehalose dosage/anaerobic device reactor end COD concentration, use pid algorithm to calculate, result performs installation electromagnetical valve and the operation of dosing pump as output valve, regulation and control terminal；In step 5. middle trehalose automatic Dosing System, the setting value of trehalose dosage/anaerobic device reactor end COD concentration is 0.5 ~ 1.0.

Aerobic Co-metabolism the most according to claim 1 processes the method for brown coal upgrading waste water, it is characterised in that: the COD volumetric loading of step 3. middle aerobic reactor is 1.2 kgCOD/ (m³Or 1.5kgCOD/ (m d)³D), hydraulic detention time is 20h or 24h.

Aerobic Co-metabolism the most according to claim 1 processes the method for brown coal upgrading waste water, it is characterised in that: the dosage of the seed sludge in step 4. middle aerobic reactor is 5g/L.

Aerobic Co-metabolism the most according to claim 1 processes the method for brown coal upgrading waste water, it is characterised in that: step 5. middle trehalose dosage/anaerobic reactor end COD concentration set point is 0.75 ~ 0.85.