Treatment technology for sulfur-containing and incinerator wastewater

Abstract

The invention discloses a treatment technology of sulfur-containing and incinerator wastewater, and relates to the technical field of sewage treatment. The treatment technology comprises the following steps: step 1, preparing a complex microbial inoculant, and activating the complex microbial inoculant to obtain an activated microbial inoculant; and step 2, adding the activated microbial inoculum prepared in the step 1 into a biochemical treatment system, and decomposing harmful substances in the wastewater through growth and metabolism of bacteria to achieve the purpose of wastewater treatment. Through the technology, the wastewater treatment effect can be greatly improved, the wastewater load is improved, the wastewater treatment operation cost is reduced, and meanwhile, the problem of secondary pollution generated in the wastewater treatment process is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly to a treatment technology for sulfur-containing and incinerator wastewater. Background Art

[0002] Sulfur-containing and incinerator wastewater is mainly characterized by high sulfur and salt content. The wastewater has an inhibitory effect on the growth and metabolism of microbial bacteria, resulting in an insignificant biochemical treatment effect of the wastewater and a high cost for the wastewater to meet the discharge standards.

[0003] The main impacts of sulfur-containing wastewater on the environment are as follows:

[0004] (1) Malodorous gases affect the surrounding environment and physical health

[0005] For an industrial sewage treatment system adopting the "hydrolysis acidification + contact oxidation" process, sulfides are mainly generated in the hydrolysis acidification tank. Some sulfides diffuse into the air in the form of hydrogen sulfide (H2S) gas, which easily leads to excessive hydrogen sulfide emissions and affects the surrounding environment. H2S is a toxic colorless gas with the smell of rotten eggs. Usually, hydrogen sulfide poisoning can cause many harms to the body, mainly systemic diseases with damage to the central nervous system, respiratory nervous system, and other multiple internal organs. Once hydrogen sulfide poisoning occurs, it can cause mild dyspnea and even death in severe cases. In a poorly ventilated operating environment, it is extremely easy to trigger safety production accidents.

[0006] (2) Corrosive effect on sewage treatment equipment and facilities

[0007] Hydrogen sulfide in the wastewater can react with ferrous ions (Fe 2+ ) in the water to form ferrous sulfide (FeS) and ferrous hydroxide [Fe(OH)2], causing corrosion to iron and steel equipment. Under humid conditions, some H2S volatilized into the air will also be oxidized by bacteria to sulfurous acid (H2SO3) or sulfuric acid (H2SO4), corroding calcium carbonate and steel bars exposed in reinforced concrete structures.

[0008] (3) Increasing the energy consumption of the sewage treatment system

[0009] Sulfides in the wastewater have strong reducibility and will be preferentially oxidized in the aerobic tank, consuming a large amount of dissolved oxygen in the water in a short time. Research shows that 1 g of sulfur in the form of sulfide (S 2- ) is equivalent to 2 g of COD. After a large amount of sulfides in the effluent of the hydrolysis acidification tank enter the contact oxidation tank, it will greatly increase the aeration demand in the tank and increase the aeration energy consumption.

[0010] The main impacts of high-salt wastewater on microorganisms are as follows:

[0011] (1) Causing microbial dehydration and death

[0012] In the case of a relatively high salt concentration, the change in osmotic pressure is the main factor. As the salt concentration increases, the concentration of the internal solution of the bacteria is lower than that of the external environment. Also, due to the property that water moves from a low concentration to a high concentration, a large amount of water in the bacteria is lost, causing a change in the internal biochemical reaction environment, ultimately disrupting its biochemical reaction process until it is interrupted and the bacterial cells die.

[0013] (2) Interfere with and block the absorption process of microorganisms to cause death

[0014] The cell membrane has the property of selective permeability to filter out substances harmful to the life activities of bacteria and absorb substances beneficial to its life activities. This absorption process is directly affected by the solution concentration, substance purity, etc. of the external environment. The addition of salt causes interference or blockage in the absorption environment of bacteria, ultimately resulting in the inhibition or even death of the bacterial vital activity. This situation varies greatly depending on the individual situation of bacteria, the variety of bacteria, the type of salt, and the salt concentration.

[0015] (3) Poison microorganisms to death

[0016] Some salts enter the bacteria through their life activities, disrupting the internal biochemical reaction process. Some interact with the cell membrane of the bacteria, causing a change in its properties so that it no longer plays a protective role or can no longer absorb certain substances beneficial to the bacteria, thereby leading to the inhibition of the bacterial vital activity or the death of the bacterial cells.

[0017] Therefore, there is an urgent need for microbial agents for sulfur-containing and incinerator wastewater to improve the treatment effect of sulfur-containing wastewater. Summary of the Invention

[0018] In order to solve the technical problem that the high salt and high sulfur in sulfur-containing and incinerator wastewater impact the biochemical system, resulting in poor biochemical treatment effect of the wastewater, the present invention provides a method for treating sulfur-containing and incinerator wastewater. Through the technology of the present invention, the treatment effect of the wastewater can be significantly improved, the load of the wastewater can be increased, the treatment operation cost of the wastewater can be reduced, and at the same time, the problem of secondary pollution generated during the wastewater treatment process can be avoided.

[0019] To achieve the above object, the present invention provides a method for treating sulfur-containing and incinerator wastewater, comprising the following steps:

[0020] Step 1: Prepare a composite microbial agent and activate it to obtain an activated microbial liquid;

[0021] Step 2: Add the activated microbial liquid prepared in Step 1 to the biochemical treatment system, and decompose the harmful substances in the wastewater through the growth and metabolism of the microorganisms to achieve the purpose of treating the wastewater.

[0022] Further, the strains of the compound bacterium agent described in step 1 are Bacillus subtilis, Stenotrophomonas, Rhodopseudomonas capsulate, and Thiobacillus thioparus.

[0023] Further, in the compound bacterium agent, calculated by weight fraction, the ratio of Bacillus subtilis to Stenotrophomonas is 15 - 30:22 - 30.

[0024] Further, in the compound bacterium agent, calculated by weight fraction, the ratio of Bacillus subtilis to Rhodopseudomonas capsulate is 15 - 30:18 - 20.

[0025] Further, in the compound bacterium agent, calculated by weight fraction, the ratio of Bacillus subtilis to Thiobacillus thioparus is 15 - 30:20 - 45.

[0026] Further, the activation in step 1 is to mix the compound bacterium agent, sulfur - containing wastewater, and clear water in a ratio of 1:30:70, and then aerate and culture for 24 - 90 hours.

[0027] Further, the salt content in the sulfur - containing wastewater is 150 - 200 mg / L (calculated as sulfate).

[0028] Further, for every ton of sulfur - containing and incinerator wastewater treated in step 2, 5 - 20 kg of the activated compound microbial bacteria liquid needs to be added, and the reaction residence time is 20 - 90 hours according to the wastewater inlet load.

[0029] Further, the biochemical treatment system includes an aerobic device with an aeration system or the aerobic section of a biological system.

[0030] The application of the above - mentioned method provided by the present invention in the fields of sewage treatment and environmental protection.

[0031] Beneficial effects

[0032] The treatment method of sulfur - containing and incinerator wastewater provided by the present invention, aiming at the characteristics of sulfur - containing and incinerator wastewater, realizes the up - to - standard discharge of the full - biological treatment process of this wastewater, provides technical feasibility, and provides a guarantee for enterprises to increase production and efficiency. Brief description of the drawings

[0033] Figure 1This is the process flow diagram of the present invention. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0035] The present invention is suitable for the treatment of wastewater containing sulfur and incinerator wastewater, and the present invention uses a composite microbial inoculant specially developed for this wastewater. The Bacillus subtilis used in the embodiment was purchased from Beijing Saifuwei Environmental Engineering Technology Co., Ltd.; Stenotrophomonas was purchased from Beijing Saifuwei Environmental Engineering Technology Co., Ltd.; Rhodopseudomonas capsulate was purchased from Beijing Saifuwei Environmental Engineering Technology Co., Ltd.; Thiobacillus thioparus was purchased from Beijing Saifuwei Environmental Engineering Technology Co., Ltd.

[0036] Example 1

[0037] The daily wastewater production in a sewage treatment system of a chemical plant in Nantong is as follows:

[0038] Table 1 Composition of process wastewater (from material balance)

[0039]

[0040] Table 2 Wastewater production situation

[0041]

[0042]

[0043] The above table shows the basic situation of the generated wastewater. W1 is incinerator wastewater, and W2 and W3 are sulfur-containing wastewater.

[0044] The implementation process of the present invention is as follows:

[0045] The incinerator wastewater enters the regulation tank, dilutes the COD to about 2500 mg / L, and adjusts the salt molecules to 100 - 120 mg / L. Then it is introduced into the UASB system. After staying for a period of time, the UASB effluent enters the pre-acidification tank, and the pH is adjusted to 7.5 - 8.5. The wastewater after pre-acidification treatment is connected to the A / O system.

[0046] The sulfur-containing wastewater is directly introduced into the A / O system.

[0047] Mass ratio of the compound microbial inoculum: Bacillus subtilis: Stenotrophomonas: Rhodopseudomonas capsulate: Thiobacillus thioparus = 22%: 25%: 18%: 35%.

[0048] The compound microbial inoculum is mixed in the ratio of compound inoculum: sulfur-containing and incinerator wastewater: clear water = 1%: 30%: 70%, and aerated and cultured for 60 hours to obtain the activated and domesticated compound microbial liquid.

[0049] Using the existing aerobic tank, start continuous water inlet, treating 1000 cubic meters per day. At the same time, supplement 5000 kg of the activated and domesticated microbial liquid to the aerobic biochemical system every day, and detect the relevant indicators of the wastewater in the system.

[0050] The effect after 30 days (average) of the treatment by the technology of the present invention is shown in Table 3 as follows:

[0051] Table 3

[0052] Item Before treatment After treatment Removal rate (%) COD 1217.38 mg / L 275.89 mg / L 77.34

[0053] The invention can realize continuous water inlet and continuous water outlet of the system, and the continuous and automatic feeding process of the compound biological strains, which can ensure the stable treatment effect of the system wastewater, the stable discharge of the effluent up to the standard, without any secondary pollution, and without special management requirements.

[0054] Comparative Example 1

[0055] Carried out with reference to Example 1, in which only the mass ratio of the compound microbial inoculum is adjusted to Bacillus subtilis: Stenotrophomonas: Rhodopseudomonas capsulate: Thiobacillus thioparus = 3:1:3:3, and other steps and parameters remain unchanged. The final effect is shown in Table 4 as follows:

[0056] Table 4

[0057] Item Before treatment After treatment Removal rate (%) COD 1346.27 mg / L 423.67 mg / L 68.53

[0058] Comparative Example 2

[0059] Carried out with reference to Example 1, in which only the mass ratio of the compound microbial inoculum is adjusted to Bacillus subtilis: Rhodopseudomonas capsulate: Thiobacillus thioparus = 1:3:3:3, and other steps and parameters remain unchanged. The final effect is shown in Table 5 as follows:

[0060] Table 5

[0061] Item Before treatment After treatment Removal rate (%) COD 1297.64 mg / L 597.82 mg / L 53.93

[0062] The embodiments provided above are not intended to limit the scope covered by the present invention, nor are the described steps intended to limit the order of their execution. Obvious improvements made by those skilled in the art to the present invention in combination with the existing well-known general knowledge also fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for treating wastewater containing sulfur and incinerator, characterized in that, It includes the following steps: Step 1: Prepare a composite bacterial agent and activate it to obtain a well-activated bacterial liquid; Step 2: Add the well-activated bacterial liquid prepared in Step 1 into the biochemical treatment system. Through the growth and metabolism of the bacteria, decompose the harmful substances in the wastewater to achieve the purpose of treating the wastewater; The bacterial strains of the composite bacterial agent are Bacillus subtilis, Stenotrophomonas, Rhodopseudomonas capsulate, and Thiobacillus thioparus.

2. The method according to claim 1, characterized in that, In the composite bacterial agent, calculated by weight fraction, the ratio of Bacillus subtilis to Stenotrophomonas is 15 - 30:22 - 30.

3. The method according to claim 1, characterized in that, In the composite bacterial agent, calculated by weight fraction, the ratio of Bacillus subtilis to Rhodopseudomonas capsulate is 15 - 30:18 - 20.

4. The method according to claim 1, characterized in that, In the composite bacterial agent, calculated by weight fraction, the ratio of Bacillus subtilis to Thiobacillus thioparus is 15 - 30:20 - 45.

5. The method according to claim 1, characterized in that, The activation in Step 1 is to mix the composite bacterial agent, sulfur-containing wastewater, and clear water in a ratio of 1:30:70, and then aerate and culture for 24 - 90 hours.

6. The method according to claim 1, characterized in that, In Step 2, for every ton of sulfur-containing and incinerator wastewater treated, 5 - 20 kg of the well-activated composite microbial bacterial liquid needs to be added, and the reaction residence time is 20 - 90 hours according to the wastewater inlet load.

7. The method according to claim 1, characterized in that, The biochemical treatment system includes an aerobic device with an aeration system or the aerobic section of a biological system.

8. Application of the method according to any one of claims 1 to 7 in the fields of sewage treatment and environmental protection.

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