Inoculating bacteria for detecting BOD5 of pulp and papermaking wastewater

Abstract

The application discloses a kind of inoculating bacterial agent for pulping and papermaking wastewater BOD5 detection, its preparation steps: active sludge water sample is hit to storage tank, light source is installed in the upper portion of storage tank and is continuously illuminated, sludge water is static stratification;After the sludge of precipitation is mixed with diatomite, composite enzyme agent, composite bacterial agent, nutrient agent, obtain microbial mud sample;Microbial mud sample is centrifuged, and solid phase sludge particle is obtained;Solid phase sludge particle air-drying, obtain inoculating bacterial agent.The inoculating bacterial agent for wastewater BOD5 detection provided by the application makes up the technical and market blank of lack of similar products on the market.The inoculating bacterial agent is convenient to use, only needs to activate culture for a short time to meet the requirement of pulping and papermaking wastewater BOD5 detection, avoids the need of long time domestication culture for preparing inoculating liquid when detecting BOD5 by conventional method, and shortens the detection time.Meanwhile, after the product is prepared into bacterial liquid, it can maintain high activity for a long time, meets the need of long time multiple detection.

Description

TECHNICAL FIELD

[0001] The present application relates to sewage detection technical field and microbial technology field, and particularly relates to a kind of inoculation bacterial agent for pulp and papermaking wastewater BOD5 detection. BACKGROUND

[0002] Five-day biochemical oxygen demand BOD5 is an important index for indirectly indicating the degree of water pollution by organic matter by the amount of dissolved oxygen consumed by microbial metabolism, and is one of the main monitoring indicators for evaluating wastewater treatment. For industrial wastewater, detection of BOD5 requires inoculation of liquid acclimation to achieve the ability of microorganisms to decompose organic matter during cultivation, so as to reflect the true results of water quality BOD5. However, in reality, due to environmental and cultivation conditions, the acclimation period is long, resulting in unstable microbial species and quantity of acclimated inoculum, and unsatisfactory acclimation effect of inoculum, which does not meet the technical standards of BOD5 detection requirements. At the same time, there is a lack of inoculation bacterial agent extraction technology on the market, and a lack of finished products containing protozoa and various bacteria. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application aims to provide an inoculation bacterial agent for pulp and papermaking wastewater BOD5 detection to fill the technical gap and market gap in the field.

[0004] The present application scheme includes the following main contents:

[0005] An inoculation bacterial agent for wastewater BOD5 detection includes the following preparation steps:

[0006] (1) First, the activated sludge water sample is poured into a storage tank, a light source is installed above the storage tank for continuous illumination, and the sludge water is statically stratified;

[0007] Through illumination, the specific microorganisms in the activated sludge are made to hide in the sludge layer by using the light-avoiding movement rule of protozoa, so that the high-activity microorganisms in the sludge reach a saturated state.

[0008] (2) The precipitated sludge is mixed with diatomite, composite enzyme agent, composite bacterial agent and nutrient agent to obtain a microbial sludge sample;

[0009] (3) The microbial sludge sample is centrifuged, and a flocculating agent is added during centrifugation to obtain solid-phase sludge particles;

[0010] Diatomite as a microbial affinity carrier is beneficial to the growth and enrichment of microorganisms, and in combination with composite enzyme agent, composite bacterial agent and nutrient agent treatment, a large number of high-activity microorganisms are obtained.

[0011] (4) The solid-phase sludge particles are air-dried to obtain the inoculation bacterial agent.

[0012] Preferably, the light wavelength is 250-700nm, and the distance between the light source and the water surface is 20±5cm.

[0013] Preferably, the mass ratio of the sludge to the diatomite is 1:1-5, and the mass ratio of the diatomite, the compound bacterial agent, the compound enzyme agent, and the nutrient agent is 1-2:1-2:1-2:1-2.

[0014] Preferably, the mass ratio of the sludge to the diatomite is 1:5, and the mass ratio of the diatomite, the compound bacterial agent, the compound enzyme agent, and the nutrient agent is 1:1:1:1.

[0015] Preferably, the compound bacterial agent comprises Nocardia corallina, Bacillus subtilis, Bacillus mycoides, Bacillus megaterium, Bacillus cereus, Bacillus thuringiensis, Rhodopseudomonas palustris, and Saccharomyces cerevisiae, and the viable bacterial count of each bacterial agent is at least 10 8 cfu / mL.

[0016] Preferably, the compound enzyme agent comprises amylase, protease, cellulase, pectinase, and glucanase, and the enzyme activity of each enzyme is not less than 5000u / g.

[0017] Preferably, the nutrient agent comprises beef extract, peptone, urea, threonine, and glucose.

[0018] Preferably, the nutrient agent comprises beef extract 3g, peptone 10g, urea 5g, threonine 0.5g, and glucose 10g.

[0019] The inoculated bacterial agent has good application prospect in detecting BOD5 of wastewater.

[0020] In the embodiment, the activated sludge is derived from an AO system for treating pulp and papermaking wastewater.

[0021] It should be noted that, in the present application, the light wavelength of about 500nm refers to 250-700nm, the distance between the incandescent lamp and the water surface of about 20cm refers to 20±5cm, the concentration of PAM of about 5‰ refers to 3-7‰, and the water content of about 50% refers to 50%±10%.

[0022] The bacteria in the complex bacterial agent are preferably isolated from pulp wastewater by a conventional method, and a commercially available bacterial agent can also be used. The alpha-amylase (derived from Aspergillus niger), protease (derived from Bacillus subtilis), cellulase (derived from Trichoderma viride), pectinase (derived from Aspergillus niger), and beta-glucanase (derived from Trichoderma viride) are all commercially available products. The nutrient agent is prepared by using commercially available products.

[0023] The present application has the following beneficial effects:

[0024] The present application provides an inoculum for BOD5 detection of wastewater, which fills the technical and market gap of similar products on the market. The product of the present application can meet the BOD5 detection requirements of industrial wastewater including pulp and papermaking wastewater.

[0025] The inoculum of the present application is convenient to use, and only needs to be cultured for a short time after adding water to meet the BOD5 detection requirements of pulp and papermaking wastewater, avoiding the need for long-term acclimation and culture to prepare inoculum when detecting BOD5 by conventional methods, thereby shortening the detection time. At the same time, the product can maintain high activity for a long time after being prepared into a bacterial solution, meeting the needs of long-term and multiple detections. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The present application provides an inoculum for BOD5 detection of wastewater, which fills the technical and market gap of similar products on the market. The product of the present application can meet the BOD5 detection requirements of industrial wastewater including pulp and papermaking wastewater. DETAILED DESCRIPTION

[0027] In order to facilitate the technical personnel to understand the technical content of the present application, the present application will be further described in detail below in combination with specific examples.

[0028] Example 1 Preparation of an inoculum for BOD5 detection of pulp and papermaking wastewater

[0029] (1) First, the activated sludge water sample is poured into a storage tank, and a plurality of rows of incandescent lamps are installed above the storage tank for continuous illumination. The wavelength of the light of the incandescent lamp is about 500 nm, and the distance between the incandescent lamp and the water surface is about 20 cm. The activated sludge water sample is static stratification, and the motile protozoa in the activated sludge water sample all hide in the sludge layer to avoid light;

[0030] (2) Then, the sludge after precipitation is pumped into a sample mixing stirrer by a vacuum pump, and diatomite, a complex enzyme agent, a complex bacterial agent, and a nutrient agent are added for continuous stirring and mixing to obtain a microbial sludge sample;

[0031] The mass ratio of the sludge to diatomite is 1:5, and the mass ratio of diatomite, the complex bacterial agent, the complex enzyme agent, and the nutrient agent is 1:1:1:1;

[0032] The composition of the complex microbial agent is: Nocardia corallina, Bacillus subtilis, Bacillus mycoides, Bacillus megaterium, Bacillus cereus, Bacillus thuringiensis, Rhodopseudomonas palustris, Saccharomyces cerevisiae; in each microbial agent, the number of viable bacteria is 10 8 cfu / mL.

[0033] The composition of the complex enzyme agent is: amylase, protease, cellulase, pectinase and glucanase; the enzyme activity of the complex enzyme agent is 5000u / g.

[0034] The composition of the nutrient agent is: beef extract 3g, peptone 10g, urea 5g, threonine 0.5g and glucose 10g.

[0035] (3) The mixed microbial sludge sample is pumped into a horizontal screw centrifuge by a vacuum pump, a polyacrylamide (PAM) coagulant is added at the inlet of the centrifuge, the concentration of PAM is controlled at about 5‰, and the sludge and water are separated under the condition of high-speed operation of the centrifuge, the filtered liquid is discharged from the liquid section of the centrifuge, and the precipitated solid sludge particles are pushed to the end of the drum cone by the feed screw, and discharged from the discharge port;

[0036] (4) The solid sludge particles at the discharge port fall from the centrifuge onto the fiber screen, are laid flat, the screen is placed in the air drying warehouse for air drying, the room temperature and air force are adjusted to ensure that the sludge does not mildew. At the same time, the moisture content of the sludge is measured, and when the moisture content is about 50%, the sludge sample is bagged;

[0037] (5) The bagged sludge sample is vacuum packaged by a full-automatic vacuum sealing packaging machine, the production batch is pasted, and the packaged sludge sample is transported to a 2-8℃ low-temperature cold storage for storage;

[0038] (6) When the product is used, the water and the microbial agent are mixed at a ratio of 100:1, aeration is carried out, and the microorganisms meet the experimental requirements of BOD5 inoculum (a large number of tight flocs, good settling property and high microbial activity) after continuous culture for two days, and can be directly used for BOD5 detection of pulping and papermaking wastewater.

[0039] Experimental example: selection of BOD5 inoculum preparation conditions

[0040] 1. Diatomite addition experiment

[0041] The precipitated sludge was taken in triplicate, mixed with diatomite at a mass ratio of 1:1, 1:3 and 1:5 respectively to prepare mixed samples, and other steps were performed according to the above-mentioned Example 1 to prepare inoculant products. Each 0.05 g of the inoculant products was used to prepare 10 ml of bacterial suspension, and the glucose-glutamic acid standard solution was measured. 5 ml of the bacterial suspension was added to each liter of dilution water, and a control experiment was performed with an A / O system bacterial suspension (i.e. inoculum prepared by traditional method). The experiment was repeated three times. The results of the three determination experiments and analysis are shown in Table 1.

[0042] Table 1

[0043]

[0044] As shown in Table 1, the measured values of the bacterial agent and the bacterial liquid at three different ratios are all within the range of 180-230 mg / L, which meets the standard requirements. Among them, the standard deviation is the smallest and the repeatability is the best when the mixed ratio of the bacterial agent product is 1:5, which is better than other ratios. Therefore, the optimal amount of diatomite is determined to be 5 times the mass of the sludge.

[0045] 2. Enzyme agent, composite bacterial agent and nutrient agent addition amount experiment

[0046] Bacterial agent A: no enzyme agent, composite bacterial agent and nutrient agent is added to prepare the bacterial agent. Bacterial agent B: enzyme agent, composite bacterial agent and nutrient agent are added to prepare the bacterial agent. Other steps are performed according to the above-mentioned Example 1.

[0047] Each is mixed at a ratio of water to bacterial agent of 100:1 to prepare 5 L for aeration experiment, BOD is measured, and the growth of microorganisms in the floc is observed under a microscope. The results of the enzyme agent, composite bacterial agent and nutrient agent addition amount experiment and analysis are shown in Table 2, and the analysis of the microbial observation results is shown in Table 3.

[0048] Table 2

[0049]

[0050] As shown in Table 2, the measured value of the glucose-glutamic acid standard solution of bacterial agent A is less than 180-230 mg / L after one week, while the measured value of bacterial agent B is within the range of 180-230 mg / L after three weeks of continuous experiment, which meets the standard requirements.

[0051]

[0052] As shown in Table 3, the activity of the bacterial agent A mixture decreases after one week, and part of the microorganisms die, which cannot consume organic matter, etc. However, the microorganisms of the inoculated bacterial agent B still maintain good activity without fresh sludge.

[0053] The BOD5 (blank value) of the inoculated dilution water using the traditional method and the inoculant of the application is tested respectively to determine the stability of the blank value in the two different methods, and the BOD5 of the quality control sample is measured to test the accuracy of the two different methods.

[0054] 3. BOD5 determination of the inoculum of A / O system

[0055] The A / O system inoculum is used for inoculation, the BOD5 (blank value) of the inoculated dilution water is observed through experiments, the BOD5 of the quality control sample is detected, and the accuracy of the detection result is tested (Table 4).

[0056] Table 4 BOD5 (blank value) of the dilution water after inoculation using the A / O system inoculum and the detection result of the quality control sample

[0057]

[0058] As shown in Table 4, the BOD5 (blank value) of the inoculated dilution water is <1.5 mg / L using different inoculation amounts, the sample determination can be completed, and the value of the quality control sample is qualified.

[0059] 4. BOD5 determination of the inoculant of the application

[0060] The inoculant of the application is used, the inoculation amount of the dilution water is 5, 10 and 15 mL / L respectively, the BOD5 (blank value) is observed through multiple experiments, and the quality control sample is detected.

[0061] Table 5 BOD5 (blank value) of the dilution water after inoculation using the inoculant of the application and the detection result of the quality control sample

[0062]

[0063] As shown in Table 5, the BOD5 (blank value) of the inoculated dilution water is <1.5 mg / L using the inoculation amount of 5, 10 and 15 mL / L, the sample determination can be completed, and the value of the quality control sample is qualified.

[0064] The above only describes some preferred embodiments of the application, and does not limit the application, the protection scope of the application is not limited to the above. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. An inoculum agent for detecting BOD5 in wastewater, characterized in that, The preparation comprises the following steps: (1) first, the activated sludge water sample is poured into a storage tank, a light source is installed above the storage tank for continuous illumination, and the sludge water is statically stratified; (2) the sludge after precipitation is mixed with diatomite, a composite enzyme agent, a composite bacterial agent and a nutrient agent to obtain a microbial sludge sample; The mass ratio of the sludge to the diatomite is 1:1-5, and the mass ratio of the diatomite, the composite bacterial agent, the composite enzyme agent and the nutrient agent is 1-2:1-2:1-2:1-2; The composition of the complex microbial agent is: Nocardia corallina, Bacillus subtilis, Bacillus mycoides, Bacillus megaterium, Bacillus cereus, Bacillus thuringiensis, Rhodopseudomonas palustris, Saccharomyces cerevisiae; in each microbial agent, the number of viable bacteria is at least 10 8 cfu / mL; The composite enzyme agent comprises amylase, protease, cellulase, pectinase and glucanase, and the enzyme activity of each enzyme is not less than 5000u / g; (3) the microbial sludge sample is centrifuged, and a flocculating agent is added during the centrifugation to obtain solid-phase sludge particles; (4) the solid-phase sludge particles are air-dried to obtain the inoculant.

2. The inoculant of claim 1, wherein, The wavelength of the light is 250-700nm, and the distance between the light source and the water surface is 20±5cm.

3. The inoculant of claim 1, wherein, The mass ratio of the sludge to the diatomite is 1:5, and the mass ratio of the diatomite, the composite bacterial agent, the composite enzyme agent and the nutrient agent is 1:1:1:

1.

4. The inoculant of claim 1, wherein, The nutrient agent comprises beef extract, protein peptone, urea, threonine and glucose.

5. The inoculant of claim 1, wherein, The nutrient agent comprises beef extract 3g, protein peptone 10g, urea 5g, threonine 0.5g and glucose 10g.

6. The application of the inoculant of claim 1 in detecting the BOD5 of wastewater.

7. Use according to claim 6, characterized in that, The wastewater is pulp and papermaking wastewater.

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