Biological treatment method for o-chlorophenol wastewater

Abstract

The invention discloses a biological treatment method for o-chlorophenol wastewater, and belongs to the field of biological treatment of high-concentration o-chlorophenol wastewater. According to the treatment method, wastewater is sequentially subjected to activation and culture of an o-chlorophenol exclusive solid strain and wastewater treatment, the process is easy to operate and efficient in reaction, o-chlorophenol can be degraded and finally oxidized into CO2 and H2O, and o-chlorophenol is degraded. The wastewater with the influent o-chlorophenol concentration of 2,000 mg / L or below can be treated, professional biodegradation can be performed, and the o-chlorophenol degradation efficiency is higher than 85%. According to the method, a common biological method is upgraded and enhanced, and the application range of biological treatment of o-chlorophenol wastewater is widened.

Description

Technical Field

[0001] This invention belongs to the field of biological methods for treating high-concentration o-chlorophenol wastewater, and specifically relates to a biological treatment method for o-chlorophenol wastewater. Background Technology

[0002] Chlorophenols are highly toxic and difficult to biodegrade, exhibiting teratogenic, carcinogenic, mutagenic, and genotoxic effects. These substances are widely found in wastewater from paper mills, pesticides, dyes, and pharmaceuticals. The stable conjugated system formed by the p electrons of the chlorine atom and the π bond on the benzene ring contributes to the strong toxicity and resistance to degradation of chlorophenols. Furthermore, the activity of these substances varies depending on the number of chlorine atoms and their substitution positions.

[0003] o-Chlorophenol is an aromatic compound that is toxic and flammable. It produces harmful gases such as carbon monoxide and hydrogen chloride and is difficult to degrade. It is used in pharmaceuticals, pesticides, dyes, and other organic synthesis raw materials. Chlorinated hydrocarbons and their derivatives are also toxic and difficult to degrade naturally, and are listed as key pollutants.

[0004] Currently, there are three main categories of methods for treating o-chlorophenol wastewater: physical adsorption, biological methods, and chemical methods (advanced oxidation and chemical reduction). All of these methods suffer from drawbacks to varying degrees, such as high treatment costs and high energy consumption. Furthermore, conventional biological methods for treating o-chlorophenol wastewater have disadvantages such as low influent concentration limits and unstable operation. Therefore, this patent discloses a biological treatment method for o-chlorophenol wastewater, capable of treating o-chlorophenol wastewater with a maximum concentration of 2000 mg / L. This method represents an upgrade and enhancement of conventional biological methods, broadening the applicability of biological treatment for o-chlorophenol wastewater. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by disclosing a biological treatment method for o-chlorophenol wastewater. The process is simple to operate and highly efficient, enabling professional biodegradation of wastewater with an influent o-chlorophenol concentration of less than 2000 mg / L, with an o-chlorophenol degradation efficiency of over 85%.

[0006] This invention is implemented as follows: A biological treatment method for o-chlorophenol wastewater, characterized in that the biological treatment method includes the following steps: Step 1: Activation and culture of o-chlorophenol bacteria: 1.1 Add 0.5-1‰ o-chlorophenol-specific compound bacteria, glucose 1-1.5g / L, tap water, pH 7-8, and culture in a culture tank at 25-35℃ for 48h to activate the bacteria, DO 2-4 mg / L; 1.2 After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed.

[0007] Step 2: Wastewater Treatment 2.1. The process wastewater of o-chlorophenol, with pH adjusted to 7-8, is introduced into the o-chlorophenol wastewater biological treatment tank. The temperature is controlled at 25-35℃, and the reaction time and dissolved oxygen are controlled. 10% of activated and cultured o-chlorophenol-specific degrading bacteria solution is added to the o-chlorophenol wastewater biological treatment tank, and the o-chlorophenol-specific degrading bacteria are immobilized on polyurethane packing. 2.2 When the concentration of o-chlorophenol in the influent is less than 1000 mg / L or the COD is less than 1500 mg / L when the system is started, add 500 mg / L of COD equivalent carbon source. 2.3. Increase the load in a gradient of 500 mg / L for o-chlorophenol concentration or 500-1000 mg / L for COD, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent o-chlorophenol concentration; the maximum influent o-chlorophenol concentration at full load can reach 2000 mg / L. 2.4 The hydraulic residence time (HRT) is: Influent o-chlorophenol concentration not exceeding 1000 mg / L, HRT 48h; Influent o-chlorophenol 1000-2000 mg / L, HRT 72h.

[0008] 2.5 Processing Technology: An aerobic biochemical process was adopted; the reaction tank was inoculated with activated o-chlorophenol-specific degrading bacteria and 70% polyurethane packing.

[0009] Furthermore, the feature is that during the strain domestication process in steps 2.1 to 2.3, the influent pH is 7-8, the reaction temperature is 25-35℃, and the optimal o-chlorophenol influent concentration is within 2000 mg / L.

[0010] Furthermore, the o-chlorophenol-specific solid bacteria is characterized by being prepared from microbial agents made from strains of Pseudomonas, Bacillus brevis, Delfordia, and Sphingomonas in a mass ratio of 1:1:1:1.

[0011] Furthermore, the implementation method of the o-chlorophenol-specific degrading bacteria and polyurethane packing is as follows: the o-chlorophenol-specific degrading bacteria agent is added to the reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%, the residence time is controlled at 24-72h, and COD and TOC indicators are measured. After the o-chlorophenol degradation rate is greater than 90%, the removal effect is stable for 5-10 days. The o-chlorophenol concentration in the influent is gradually increased in a 500 mg / L o-chlorophenol concentration gradient, and 50-60% of the water is replaced in each batch until the influent load is the target influent o-chlorophenol concentration.

[0012] The advantages of this invention compared to the prior art are as follows: 1. This invention can treat high-concentration o-chlorophenol wastewater using a fully biological method, with good results, low cost, and no secondary pollution.

[0013] 2. The o-chlorophenol-specific degrading bacteria used in this invention are formulated according to a unique formula and can treat high-concentration o-chlorophenol wastewater. When o-chlorophenol concentration is less than 2000 mg / L, it can perform professional biodegradation with an o-chlorophenol degradation efficiency of over 85%.

[0014] 3. This invention can treat high-concentration o-chlorophenol wastewater using a fully biological method, which can degrade o-chlorophenol and ultimately oxidize it into CO2 and H2O, thus degrading o-chlorophenol. Attached Figure Description

[0015] Figure 1 This is a diagram showing the TOC removal effect after processing in an embodiment of the present invention; Figure 2 This is a diagram showing the COD removal effect after processing in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following examples provide a more detailed description of the invention. It should be noted that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0017] A biological treatment method for o-chlorophenol wastewater is characterized in that the wastewater undergoes sequential activation and cultivation of o-chlorophenol-specific solid microbial strains, followed by wastewater treatment. The specific implementation scheme is as follows: 1. Add 0.5-1‰ of o-chlorophenol-specific compound bacteria, 1-1.5 g / L glucose, tap water, pH 7-8, and culture in a culture tank at 25-35℃ with aeration (DO 2-4 mg / L) for 48 hours to activate the bacterial strain; the o-chlorophenol-specific solid is a microbial agent prepared from strains of Pseudomonas, Bacillus brevis, Delfordia, and Sphingomonas in a 1:1:1:1 ratio (mass ratio); 2. After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed; 3. Adjust the pH of the process wastewater to 6-9. If the concentration of o-chlorophenol in the system influent is less than 1000 mg / L (or COD less than 1500 mg / L, COD preferred), a 500 mg / L COD equivalent carbon source can be added. 4. The implementation method of using o-chlorophenol-specific degrading bacteria and polyurethane packing for immobilization is as follows: The o-chlorophenol-specific degrading bacteria agent is added to the reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%. The residence time is controlled at 24-72 hours. Sampling and testing of indicators such as COD and TOC are performed. After the o-chlorophenol degradation rate is greater than 90%, the removal effect is stable for 5-10 days. The concentration of o-chlorophenol in the influent is gradually increased in a 500 mg / L o-chlorophenol concentration gradient. 50-60% of the water is replaced in each batch until the influent load is the target influent o-chlorophenol concentration. 5. The appropriate biological treatment process for o-chlorophenol can be selected based on the concentration of chlorophenol in the wastewater and the actual site conditions (used alone or in combination with the conventional activated sludge process) and retention time: an aerobic biological process can be used, with the aerobic reactor already inoculated with o-chlorophenol-specific degrading bacteria and 70% polyurethane packing. The hydraulic retention time is: 48h for influent o-chlorophenol concentrations below 1000mg / L; 72h for influent o-chlorophenol concentrations of 1000-2000 mg / L.

[0018] The following are specific examples illustrating the application of the biological treatment method for o-chlorophenol wastewater: Example

[0019] The target influent concentration of o-chlorophenol in a wastewater treatment project is 1000 mg / L. Activated o-chlorophenol-specific degrading bacteria were added at a dosage of 10% to an aerobic treatment reactor containing 70% polyurethane packing. The retention time was controlled, and the influent o-chlorophenol concentration was gradually increased in 500 mg / L gradients, with 50-60% of the water replaced per batch, until the influent load reached the target influent o-chlorophenol concentration. Analysis results showed that the o-chlorophenol removal rate in the aerobic effluent was greater than 85% after 48 hours. Figure 1 and 2 o-Chlorophenol can be efficiently biodegraded.

[0020] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A biological treatment method for o-chlorophenol wastewater, characterized in that, The biological treatment method includes the following steps: Step 1: Activation and culture of o-chlorophenol bacteria; Step 2: Wastewater Treatment 1.

1. The process wastewater of o-chlorophenol, with pH adjusted to 7-8, is introduced into the wastewater biological treatment tank. The temperature is controlled at 25-35℃, the reaction time is controlled and the dissolved oxygen is controlled at 2-4 mg / L. 10% of the activated culture of o-chlorophenol-specific degrading bacteria is added to the wastewater biological treatment tank, and the o-chlorophenol-specific degrading bacteria are immobilized on polyurethane packing. 1.2 When the concentration of o-chlorophenol in the influent is less than 1000 mg / L or the COD is less than 1500 mg / L when the system is started, add 500 mg / L of COD equivalent carbon source. 1.

3. Increase the load in a gradient of 500 mg / L for o-chlorophenol concentration or 500 mg / L for COD, with priority given to COD. Replace 50-60% of the water in each batch until the influent load reaches the target influent o-chlorophenol concentration; the maximum influent o-chlorophenol concentration at full load can reach 2000 mg / L. 1.4 The hydraulic residence time (HRT) is: Influent o-chlorophenol concentration not exceeding 1000 mg / L, HRT 48h; Influent o-chlorophenol 1000-2000 mg / L, HRT 72h; 1.5 Processing Technology: An aerobic biochemical process was adopted; the reaction tank was inoculated with activated o-chlorophenol-specific degrading bacteria and 70% polyurethane packing.

2. The biological treatment method for o-chlorophenol wastewater according to claim 1, characterized in that, The first step is as follows: 2.1 Add 0.5-1‰ o-chlorophenol-specific compound bacteria, 0.5-1 g / L glucose, tap water, pH 7-8, and culture in a culture tank at 25-35℃ for 48 hours to activate the bacteria, with DO 2-4 mg / L; 2.2 After the bacterial strain is activated, the bacterial density is measured, and it reaches 1×10⁻⁶ under a microscope. 9 CFU / mL indicates that activation culture has been completed.

3. The biological treatment method for o-chlorophenol wastewater according to claim 1, characterized in that, During the strain domestication process in steps 2.1 to 2.3, the influent pH is 7-8, the reaction temperature is 25-35℃, and the optimal o-chlorophenol influent concentration is within 2000 mg / L.

4. The biological treatment method for o-chlorophenol wastewater according to claim 1, characterized in that, The o-chlorophenol-specific solid bacteria are prepared by mixing microbial agents made from Pseudomonas, Bacillus brevis, Delfordia, and Sphingosine monocytogenes strains in a mass ratio of 1:1:1:

1.

5. The biological treatment method for o-chlorophenol wastewater according to claim 1, characterized in that, The implementation method of using o-chlorophenol-specific degrading bacteria and polyurethane packing for fixation is as follows: o-chlorophenol-specific degrading bacteria agent is added to a reaction tank containing 70% polyurethane packing in 2-3 batches at a dosage of 10%. The residence time is controlled at 24-72 hours. COD and TOC indicators are measured. After the o-chlorophenol degradation rate is greater than 85%, the removal effect is stable for 5-10 days. The concentration of o-chlorophenol in the influent is gradually increased in a 500 mg / L o-chlorophenol concentration gradient. 50-60% of the water is replaced in each batch until the influent load is the target influent o-chlorophenol concentration.

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