ORGANIC INDUSTRIAL TAILWATER TREATMENT METHOD BASED ON SIMULTANEOUS COMBINATION OF OZONATION AND BIODEGRADATION (SCOB)

Abstract

An organic industrial tailwater treatment method based on simultaneous combination of ozonation and biodegradation (SCOB), includes: placing a sponge carrier that is internally attached and grown with a biofilm in a recycle reactor; introducing air into an ozone generator to generate ozone; and introducing the ozone into the recycle reactor; where the ozone output of the recycle reactor is adjusted through a flow meter and an ozone generator adjustment knob, the sponge carrier is uniformly fluidized under the action of the ozone, and microorganisms loaded on the sponge carrier cooperate with the ozone to degrade pollutants. Easily degradable organic substances produced from the ozonation of the present disclosure can be quickly utilized by the microorganisms in the internal pores of the composite carrier, which improves the degradation and mineralization efficiency of pollutants.

Claims

1. An organic industrial tailwater treatment method based on simultaneous combination of ozonation and biodegradation (SCOB), comprising the steps of: placing a sponge carrier that is internally attached and grown with a biofilm in a recycle reactor; using an air pump to introduce air into an ozone generator to generate ozone; and introducing the ozone into the recycle reactor; wherein, during the process, the ozone output of the recycle reactor is adjusted through a flow meter and an ozone generator adjustment knob, the sponge carrier is uniformly fluidized under the action of the ozone, and microorganisms loaded on the sponge carrier cooperate with the ozone to degrade pollutants.

2. The organic industrial tailwater treatment method based on SCOB according to claim 1, wherein, the sponge carrier is a polyurethane sponge, and the polyurethane sponge has a porous honeycomb structure, with a pore size of 0.1 mm to 0.3 mm and a porosity of about 85% to 90%.

3. The organic industrial tailwater treatment method based on SCOB according to claim 1, wherein, the polyurethane sponge is a cube with a side length of 2 mm to 3 mm, and the polyurethane sponge has a wet density of about (0.89-0.90)/cm.sup.3.

4. The organic industrial tailwater treatment method based on SCOB according to claim 1, wherein, the sponge carrier that is attached and grown with a biofilm is prepared by the following method: taking sludge from an aerobic tank of a sewage treatment plant, and subjecting the sludge to static settling for 1 h to 3 h for separating; removing a resulting supernatant, and conducting aeration for 1 d to 3 d to activate the sludge; soaking a sponge carrier in activated sludge, stirring appropriately, and continuously aerating for 1 d to 3 d to allow the pores and framework of the sponge carrier to fully adsorb the activated sludge; transferring the sponge carrier with the activated sludge adsorbed to a complete-mix continuous-flow recycle reactor for further cultivation, and supplementing a specified amount of the to-be-treated industrial wastewater as a nutrient to enable COD:N:P=100:(5-10):(1-5); and cultivating for 7 d to 10 d.

5. The organic industrial tailwater treatment method based on SCOB according to claim 1, wherein, the recycle reactor is made of polymethyl methacrylate (PMMA), with a height of about 180 mm, an outer diameter of about 80 mm, an inner diameter of about 70 mm; a ramp of about 60° is disposed at the bottom of the recycle reactor, and the ramp can provide a shearing force to allow the sponge carrier to be better fluidized in the reactor and avoid accumulation of sponge carriers at the bottom of the reactor; and an aerator is installed on the recycle reactor to introduce ozone into the reactor, which in turn promotes the continuous fluidization of the sponge carrier in the reactor.

6. The organic industrial tailwater treatment method based on SCOB according to claim 1, wherein, wherein, the ozone is introduced at an amount of about 40 mg/(L.Math.h) to about 100 mg/(L.Math.h).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0025] FIG. 1 is a schematic diagram of the working device according to the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide an improved SCOB wastewater treatment system.

[0027] The present disclosure is further described below with reference to specific Embodiments.

[0028] The present disclosure provides an organic industrial tailwater treatment method based on SCOB, including: placing a sponge carrier that is internally attached and grown with a biofilm in a recycle reactor; using an air pump to introduce air into an ozone generator to generate ozone; and introducing the ozone into the recycle reactor; where, during the process, the ozone output of the recycle reactor is adjusted through a flow meter and an ozone generator adjustment knob, the sponge carrier is uniformly fluidized under the action of the ozone, and microorganisms loaded on the sponge carrier cooperate with the ozone to degrade pollutants.

[0029] The recycle reactor may be made of PMMA, with a height of 180 mm, an outer diameter of 80 mm, an inner diameter of 70 mm; a 60° ramp may be disposed at the bottom of the recycle reactor, and the ramp can provide a shearing force to allow the sponge carrier to be better fluidized in the reactor and avoid accumulation of sponge carriers at the bottom of the reactor; and an aerator may be installed on the recycle reactor to introduce ozone into the reactor, which in turn promotes the continuous fluidization of the sponge carrier in the reactor.

[0030] The device for the SCOB may include a mixed internal recycle reactor, an ozone generator, and a porous sponge carrier loaded with a biofilm. Air is first introduced into the ozone generator via the air pump to produce ozone, and by adjusting the flow meter and the output of the ozone generator, a specified amount of ozone is introduced into the internal recycle reactor. The sponge carrier is uniformly fluidized under the action of ozone, and the microorganisms loaded on the sponge framework cooperate with the ozone to degrade pollutants. The ozone and free radicals such as .OH generated by decomposition of the ozone first oxidize organics with low biodegradability into biodegradable small molecular substances, which are rapidly further degraded and mineralized as nutrients by microorganisms in the sponge carrier. While degrading pollutants, the system also provides nutrients for the continued growth of microorganisms, so that the system can continue to operate, thereby constructing an SCOB system.

[0031] Embodiment 1: Cultivation of a Biofilm with a Porous Sponge as a Carrier

[0032] Sludge was taken from an aerobic tank of a sewage treatment plant, and subjected to static settling for 1 h to 3 h for separating; a resulting supernatant was removed, and aeration was conducted for 1 d to 3 d to activate the sludge; a sponge carrier was soaked in activated sludge, and a resulting mixture was stirred appropriately and continuously aerated for 1 d to 3 d to allow the pores and framework of the sponge carrier to fully adsorb the activated sludge; the sponge carrier with the activated sludge adsorbed was transferred to a complete-mix continuous-flow recycle reactor for further cultivation, and a specified amount of the to-be-treated industrial wastewater was supplemented as a nutrient to enable COD:N:P=100:(5-10):(1-5); and cultivation was conducted for 7 d to 10 d.

[0033] The sponge carrier may be a polyurethane sponge, and the polyurethane sponge may have a porous honeycomb structure, with a pore size of 0.1 mm to 0.3 mm and a porosity of about 85% to 90%. The polyurethane sponge may be a cube with a side length of 2 mm to 3 mm, and the polyurethane sponge may have a wet density of about 0.89-0.90g/mL.

[0034] Embodiments 2 to 4

[0035] The effluent quality of coking wastewater from a coking plant is shown in Table 1:

TABLE-US-00001 TABLE 1 Item Range Unit pH 7.5-8.0 COD 500-600 mg/L BOD.sub.5 40-80 mg/L TN 70.8 mg/L Total phenol 56.7 mg/L Cl.sup.− 790 mg/L Chroma 600 times SS 74 mg/L COD represents chemical oxygen demand (COD); BOD.sub.5 represents five-day biochemical oxygen demand (BOD.sub.5); TN represents total nitrogen (TN) in water; and SS represents suspended solids (SS).

[0036] 500 mL of the coking wastewater effluent in Table 1 was taken and added to the SCOB reactor, and 2,000 sponge carriers loaded with a biofilm in Embodiment 1 were added at the same time. The air pump and the ozone generator were turned on, and the ozone dosage was adjusted and controlled to 40 mg/(L.Math.h), 80 mg/(L.Math.h), and 100 mg/(L.Math.h) separately by adjusting the output of the ozone generator and the flow meter. After reaction started, every 8 h was counted as a cycle, and 70% of the coking wastewater was replaced at the end of each cycle. The system began to enter a stable period from the fourth cycle, and the microorganisms adapted to the environment, and the system reached a stable state. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Increasing rate of the degradation Vibrio rate constant qinghaiensis of total Q67 COD phenol Inhibition Ozone removal rate (SCOB rate dosage SCOB relative to (untreated, Embodiment (mg/(L .Math. h)) (O.sub.3) O.sub.3) 42%) No. 2 40 38% (25%) 68.3% 38% No. 3 80 50% (40%)   65% 30% No. 4 100 75% (60%)   60% 27%

[0037] After the SCOB treatment was conducted with an ozone dosage of 100 mg/(L.Math.h), the COD removal rate of coking wastewater was about 75%, an increase of about 15% relative to the COD removal rate of about 60% achieved by the O.sub.3 degradation alone; the total phenol degradation was close to 100%, but the degradation rate constant of total phenol achieved by SCOB increased by about 60% compared to the O.sub.3 degradation alone; and the inhibition rate of coking wastewater on Vibrio qinghaiensis Q67 was reduced from 42% to 27%, a decrease of about 15%. This indicated that the SCOB had achieved the successful treatment of coking wastewater.

[0038] Embodiments 5 to 7

[0039] The tailwater quality of a pharmaceutical factory is shown in Table 3 below:

TABLE-US-00003 TABLE 3 Item Range Unit COD 180-200 mg/L BOD.sub.5 61 mg/L Chroma 60 times Turbidity 19.9 NTU SS 0.079 mg/L NH4.sup.+—N 39.21 mg/L TDS 11.18 ppt Salinity 13.13 psu Conductivity 22.77 ms/cm Resistivity 43.83 ohm-cm *COD represents chemical oxygen demand (COD); *BOD.sub.5 represents five-day biochemical oxygen demand (BOD.sub.5); *SS represents suspended solids (SS); and *TDS represents the total dissolved solids (TDS).

[0040] 500 mL of the pharmaceutical factory tailwater in Table 3 was taken and added to the reactor of the present disclosure, and 2,000 sponge carriers loaded with a biofilm were added at the same time. The air pump and the ozone generator were turned on, and the ozone dosage was adjusted and controlled to 10 mg/(L.Math.h), 20 mg/(L.Math.h), and 40 mg/(L.Math.h) by adjusting the output of the ozone generator and the flow meter. After reaction started, every 8 h was counted as a cycle, and 70% of the pharmaceutical factory tailwater was replaced at the end of each cycle. The system began to enter a stable period from the fourth cycle, and the microorganisms adapted to the environment, and the system reached a stable state. The results are shown in Table 4.

TABLE-US-00004 TABLE 4 Vibrio qinghaiensis Ozone COD Q67 dosage removal rate Inhibition rate Embodiment (mg/(L .Math. h)) (O.sub.3) (untreated, 70%) No. 5 10 34% (20%) 60% No. 6 20 62% (44%) 45% No. 7 40 80% (50%) 20%

[0041] It can be seen from the above that the SCOB treatment with an ozone dosage of 40 mg/(L.Math.h) achieved a COD removal rate of about 80%, which was superior to that of the ozone degradation alone (about 50%). The inhibitory rate of the pharmaceutical wastewater on Vibrio qinghaiensis Q67 was reduced from 70% to 20%, a decrease of about 50%. The toxicity of the effluent of the pharmaceutical factory wastewater treated by the method provided by the present disclosure was lower than that of the effluent obtained from the ozone degradation alone, indicating that the method of the present disclosure was better than the ozone degradation alone at the same dosage, and achieved the successful treatment of the pharmaceutical tailwater.

[0042] COD, total phenol, and effluent toxicity all showed that the SCOB process was better than the O.sub.3 degradation alone, and the degradation rate increased with the increase of ozone dosage. For industrial tailwater with high COD (500 to 600), an ozone dosage of 100 mg/(L.Math.h) led to a preferable degradation effect; and for industrial tailwater with low COD (180 to 200), an ozone dosage of 40 mg/(L.Math.h) led to a preferable degradation effect. Therefore, the recommended ozone dosage for SCOB degradation of organic industrial tailwater was 40 mg/(L.Math.h) to 100 mg/(L.Math.h).

[0043] In summary, the SCOB system established in the present disclosure realizes the integration of ozonation with biodegradation, which reduces the floor space and the construction and operation costs. The present disclosure requires no light source, is not affected by the turbidity and chroma of wastewater and does not involve the limitation of catalyst loading stability. Therefore, the method of the present disclosure has significant application advantages in practical applications and is an economical and engineeringly-feasible SCOB system.

[0044] The following claims are thus to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted and also what incorporates the essential idea of the invention. Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope of the invention. The illustrated embodiment has been set forth only for the purposes of example and that should not be taken as limiting the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.