A method for treating sulfur and incinerator wastewater

Abstract

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

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a treatment technology for sulfur-containing and incinerator wastewater. Background Technology

[0002] Sulfur-containing wastewater and incinerator wastewater are characterized by high sulfur and salt content. The wastewater inhibits the growth and metabolism of microorganisms, resulting in ineffective biochemical treatment and excessively high costs to meet discharge standards.

[0003] The main environmental impacts of sulfur-containing wastewater are: (1) Malodorous gases affect the surrounding environment and human health. For industrial wastewater treatment systems employing the "hydrolysis acidification + contact oxidation" process, sulfides are primarily generated within the hydrolysis acidification tank. Some sulfides diffuse into the air as hydrogen sulfide (H2S) gas, easily leading to excessive hydrogen sulfide emissions and impacting the surrounding environment. H2S is a toxic, colorless gas with a rotten egg odor. Hydrogen sulfide poisoning typically causes numerous health problems, primarily affecting the central nervous system, respiratory system, and other organs, resulting in systemic diseases. Mild cases of hydrogen sulfide poisoning can cause respiratory distress, while severe cases can be fatal. In poorly ventilated operating environments, this can easily lead to workplace accidents.

[0004] (2) Corrosion effect on sewage treatment equipment and facilities Hydrogen sulfide in wastewater can react with ferrous ions (Fe) in the water. 2+ The reaction produces ferrous sulfide (FeS) and ferrous hydroxide [Fe(OH)2], which corrode iron and steel equipment. Under humid conditions, some of the H2S volatilized into the air can also be oxidized by bacteria into sulfurous acid (H2SO3) or sulfuric acid (H2SO4), which corrodes the exposed calcium carbonate and reinforcing steel in reinforced concrete structures.

[0005] (3) Increased energy consumption of wastewater treatment system Sulfides in wastewater have strong reducing properties and are preferentially oxidized in aerobic tanks, consuming large amounts of dissolved oxygen in a short time. Studies have shown that 1g of sulfides (S...) 2- Sulfur present in the form of COD is equivalent to 2g. When a large amount of sulfides in the effluent of the hydrolysis acidification tank enters the contact oxidation tank, it will greatly increase the aeration demand in the tank and increase the aeration energy consumption.

[0006] The main effects of high-salinity wastewater on microorganisms are: (1) Causes microbial dehydration and death At high salt concentrations, changes in osmotic pressure are the primary cause. Increased salt concentration leads to a lower concentration of solution inside the bacteria compared to the external environment. Due to the property of water moving from low to high concentrations, a large amount of water is lost from the bacteria, causing changes in the internal biochemical reaction environment. Ultimately, this disrupts or even stops the biochemical reaction process, leading to bacterial death.

[0007] (2) Disrupts the absorption of substances by microorganisms, causing them to die. Cell membranes have selective permeability, filtering out substances harmful to bacterial life activities and absorbing substances beneficial to them. This absorption process is directly affected by factors such as solution concentration and substance purity in the external environment. The addition of salt disrupts or blocks this absorption environment, ultimately inhibiting bacterial activity or even causing death. This varies considerably depending on the individual bacteria, species, type of salt, and salt concentration.

[0008] (3) Causes microbial poisoning and death Some salts can enter the bacteria during their life activities, disrupting their internal biochemical processes. Others can interact with the bacterial cell membrane, causing a change in its properties and rendering it no longer protective or able to absorb certain beneficial substances, thus inhibiting the bacteria's life activities or causing the bacteria to die.

[0009] Therefore, there is an urgent need for microbial agents specifically targeting sulfur-containing and incinerator wastewater to improve the treatment effect of sulfur-containing wastewater. Summary of the Invention

[0010] To address the technical problem of poor wastewater biological treatment caused by the impact of sulfur-containing wastewater and high salt and sulfur content in incinerators on the biological treatment system, this invention provides a method for treating sulfur-containing wastewater from incinerators. This invention significantly improves wastewater treatment efficiency, increases wastewater load, reduces wastewater treatment operating costs, and avoids secondary pollution problems during wastewater treatment.

[0011] To achieve the above objectives, the present invention provides a method for treating sulfur-containing wastewater and incinerator wastewater, comprising the following steps: Step 1: Prepare the compound bacterial agent and activate it to obtain the activated bacterial solution; Step 2: Add the activated bacterial solution obtained in Step 1 to the biochemical treatment system. Through the growth and metabolism of bacteria, the harmful substances in the wastewater are decomposed to achieve the purpose of wastewater treatment.

[0012] Furthermore, the strains of the compound microbial agent mentioned in step 1 are Bacillus subtilis, Stenotrophomonas, Rhodopseudomonas capsulate, and T. thioparus.

[0013] Furthermore, in the compound microbial agent, the ratio of Bacillus subtilis to Stenotrophomonas, calculated by weight fraction, is 15-30: 22-30.

[0014] Furthermore, in the compound microbial agent, the ratio of Bacillus subtilis to salt-tolerant Rhodopseudomonas capsulate is 15-30:18-20 by weight fraction.

[0015] Furthermore, in the compound microbial agent, the ratio of Bacillus subtilis to T. thioparus, calculated by weight fraction, is 15-30: 20-45.

[0016] Furthermore, the activation described in step 1 involves mixing the compound bacterial agent, sulfur-containing wastewater, and clean water in a ratio of 1:30:70, and then aerating and culturing for 24-90 hours.

[0017] Furthermore, the salt content in the sulfur-containing wastewater is 150-200 mg / L (calculated as sulfate).

[0018] Furthermore, in step 2, for every ton of sulfur-containing and incinerator wastewater treated, 5-20 kg of activated compound microbial inoculum solution needs to be added, and the reaction retention time is 20-90 hours depending on the wastewater influent load.

[0019] Furthermore, the biochemical treatment system includes an aerobic device or an aerobic section of a biological system with an aeration system.

[0020] The above-mentioned method provided by the present invention has applications in the fields of wastewater treatment and environmental protection.

[0021] Beneficial effects The method for treating sulfur-containing and incinerator wastewater provided by this invention addresses the characteristics of such wastewater, achieving compliant discharge through a fully biological treatment process, demonstrating technical feasibility, and providing a guarantee for enterprises to increase production and efficiency. Attached Figure Description

[0022] Figure 1This is a process flow diagram of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] This invention is suitable for the treatment of sulfur-containing and incinerator wastewater. It employs a compound microbial agent specifically developed for this type of wastewater. The *Bacillus subtilis*, *Stenotrophomonas*, *Rhodopseudomonas capsulate*, and *Thioparus* used in the examples were purchased from Beijing Saifwei Environmental Engineering Technology Co., Ltd.

[0025] Example 1 The following table shows the daily wastewater generation in the wastewater treatment system of a chemical plant in Nantong: Table 1. Composition of process wastewater (from material balance)

[0026] Table 2 Wastewater Generation Status

[0027] The table above shows the basic information on the wastewater generated. W1 is incinerator wastewater, and W2 and W3 are sulfur-containing wastewater.

[0028] The implementation process of this invention is as follows: Incinerator wastewater enters the equalization tank, where COD is diluted to approximately 2500 mg / L and salt concentration is adjusted to 100-120 mg / L. Then, it is introduced into the UASB system. After a period of time, the UASB effluent enters the pre-acidification tank, where the pH is adjusted to 7.5-8.5. The pre-acidified wastewater is then connected to the A / O system.

[0029] Sulfur-containing wastewater is directly fed into the A / O system.

[0030] The mass ratio of the compound microbial agent is: Bacillus subtilis: Stenotrophomonas: Rhodopseudomonas capsulate: T. thioparus = 22%: 25%: 18%: 35%.

[0031] The compound microbial agent is prepared by mixing the compound microbial agent, sulfur-containing wastewater from incinerators, and clean water in a ratio of 1%:30%:70%, and then aerating and culturing for 60 hours to obtain the activated and acclimatized compound microbial solution.

[0032] Using the existing aerobic tank, continuous water intake was started, treating 1000 cubic meters per day. At the same time, 5000 kg of activated and acclimatized bacterial solution was added to the aerobic biological system daily, and relevant indicators of wastewater in the system were monitored.

[0033] The results of the technology of this invention after 30 days of operation (average) are shown in Table 3: Table 3

[0034] This invention enables continuous water intake and discharge, and the continuous automatic addition of compound biological strains, ensuring stable wastewater treatment performance, stable discharge of effluent that meets standards, no secondary pollution, and no special management requirements.

[0035] Comparative Example 1 The procedure was carried out according to Example 1, except that the mass ratio of the compound microbial agent was adjusted to Bacillus subtilis: Oligotrophozoites: Salt-tolerant Rhodopseudomonas capsulatum: Thiobacillus thiophanate-methyl = 3:1:3:3, while other steps and parameters remained unchanged. The final results are shown in Table 4 below. Table 4

[0036] Comparative Example 2 The procedure was carried out according to Example 1, except that the mass ratio of the compound microbial agent was adjusted to Bacillus subtilis: salt-tolerant Rhodopseudomonas capsulatum: Thiobacillus thiophanate-methyl = 1:3:3:3, while other steps and parameters remained unchanged. The final results are shown in Table 5 below: Table 5

[0037] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for treating sulfur-containing wastewater and incinerator wastewater, characterized in that, Includes the following steps: Step 1: Prepare the compound bacterial agent and activate it to obtain the activated bacterial solution; Step 2: Add the activated bacterial solution obtained in Step 1 to the biochemical treatment system. Through the growth and metabolism of bacteria, the harmful substances in the wastewater are decomposed to achieve the purpose of wastewater treatment. The strains of the compound microbial agent are Bacillus subtilis, Stenotrophomonas, Rhodopseudomonas capsulate, and T. thioparus. The ratio of Bacillus subtilis to Stenotrophomonas was 22:22-30; The ratio of Bacillus subtilis to salt-tolerant Rhodopseudomonas capsulate was 22:18-20; The ratio of Bacillus subtilis to Thioparus was 22:20-45; The biochemical treatment system includes an aerobic device with an aeration system or an aerobic section of a biological system.

2. The processing method according to claim 1, characterized in that, The activation described in step 1 involves mixing the compound bacterial agent, sulfur-containing wastewater, and clean water in a ratio of 1:30:70, and then aerating and culturing for 24-90 hours.

3. The processing 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 activated compound microbial inoculum solution needs to be added. The reaction retention time is 20-90 hours, depending on the wastewater influent load.

4. The application of the treatment method according to any one of claims 1 to 3 in wastewater treatment.

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