A method for recycling and treating sodium saccharin wastewater

Abstract

The present invention relates to the technical field of wastewater recycling, and discloses a method for recycling and treating sodium saccharin wastewater, comprising the following steps: injecting wastewater into a sedimentation tank for large particle precipitation, and then using a filtering device to filter particulate floating objects in the wastewater; purifying the wastewater by neutralization, oxidation and flocculation in sequence; using activated sludge containing microorganisms in a bioreactor to degrade organic matter in the wastewater, and using anaerobic bacteria to degrade organic matter for high-sugar components in the wastewater; and performing secondary precipitation on the treated wastewater. The present invention monitors the sodium saccharin concentration, total bacteria and conductivity in the wastewater after secondary precipitation, thereby determining whether the liquid of the sodium saccharin wastewater after secondary precipitation meets the requirements, and the wastewater that does not meet the requirements needs to be re-entered into the treatment tank for treatment, so that the discharge quality of the wastewater can be effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater recovery, and in particular to a method for recovering and treating sodium saccharin wastewater. Background Art

[0002] Saccharin sodium is a widely used artificial sweetener, and its production and use process will produce a certain amount of wastewater. If this wastewater is not properly treated, it may cause environmental pollution.

[0003] The existing patent discloses a method for treating wastewater from the production of sodium saccharin using the phthalic anhydride method (CN106865882A), which belongs to the field of high-concentration, difficult-to-degrade organic wastewater treatment. The technology includes five operating units: a neutralization system, a distillation system, a multi-effect evaporation system, a catalytic wet oxidation system, and a biological oxidation system. In the technology disclosed in the patent, the use of the phthalic anhydride method usually requires higher temperatures and pressures, which may cause corrosion of the equipment and increase energy consumption, and benzene substances are highly flammable, which poses a safety hazard during operation and storage. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide a method for recycling and treating sodium saccharin wastewater, which solves the problems in the above-mentioned background technology.

[0005] To solve the above technical problems, according to one aspect of the present invention, more specifically, a method for recycling and treating sodium saccharin wastewater comprises the following steps:

[0006] S1. Pour wastewater into a sedimentation tank to precipitate large particles, and then use filtering equipment to filter floating particles in the wastewater;

[0007] S2, purifying the wastewater by neutralization, oxidation and flocculation in sequence;

[0008] S3, using activated sludge containing microorganisms in a bioreactor to degrade organic matter in wastewater, and using anaerobic bacteria to degrade organic matter for high sugar components in wastewater;

[0009] S4, performing secondary precipitation on the treated wastewater;

[0010] S5, combining light and catalyst for photocatalytic oxidation, and using ozone to oxidize the refractory organic matter in the wastewater;

[0011] S6. Chlorination disinfection of treated wastewater;

[0012] S7. The disinfected wastewater shall be discharged safely after reaching the safe discharge standard.

[0013] Furthermore, the neutralization method in step S2 adjusts the wastewater to neutrality by adding acid or alkali according to the pH value of the wastewater.

[0014] Furthermore, the oxidation method in step S2 uses a chemical oxidant to remove organic matter and other pollutants; wherein the chemical oxidant includes chlorine, hydrogen peroxide or ozone.

[0015] Furthermore, in the flocculation method in step S2, flocculants are added to aggregate small particles into larger particles for sedimentation; wherein the flocculants include polyaluminium chloride and polyferric sulfate.

[0016] Furthermore, in step S4, the wastewater is subjected to secondary sedimentation after chemical treatment and biological treatment, and the supernatant after the wastewater sedimentation is monitored.

[0017] Furthermore, the qualified coefficient of the liquid after secondary precipitation is determined based on the concentration of saccharin sodium, the total amount of bacteria and the conductivity in the supernatant, which are:

[0018]

[0019] in, Indicates the qualified coefficient of the liquid after secondary precipitation, represents the conductivity of the liquid, Indicates the concentration of saccharin sodium in the supernatant. Indicates the total amount of bacteria in the supernatant; and has:

[0020]

[0021] In the formula, represents the conductivity of the liquid, Indicates the current size of the electrode in the clear solution. Indicates the voltage of the electrode in the clear solution. represents the temperature coefficient, Indicates the standard temperature size, Indicates the measured temperature.

[0022] Furthermore, when When , it means that the liquid of saccharin sodium wastewater after secondary precipitation initially meets the requirements;

[0023] when When , it means that the liquid of the sodium saccharin wastewater after secondary precipitation does not meet the requirements, and the wastewater needs to re-enter step S3 for treatment.

[0024] Furthermore, the photocatalytic oxidation in step S5 utilizes high-energy electrons and holes generated by photocatalysts under light conditions to react with pollutants to degrade and remove pollutants; wherein the photocatalyst comprises titanium dioxide and zinc oxide.

[0025] Furthermore, the ozone oxidation in step S5 utilizes ozone to react with pollutants in water to form hydrogen peroxide and hydroxyl radicals.

[0026] Beneficial effects:

[0027] 1. The present invention sequentially treats sodium saccharin wastewater through chemical, biological, photocatalytic and ozone oxidation treatments, thereby comprehensively aggregating high sugar, organic floating matter and other soluble impurities in the sodium saccharin wastewater.

[0028] 2. The present invention monitors the sodium saccharin concentration, total bacteria and conductivity in the wastewater after secondary precipitation to determine whether the liquid of the sodium saccharin wastewater after secondary precipitation meets the requirements. Wastewater that does not meet the requirements needs to be re-entered into the treatment pool for treatment, which can effectively ensure the discharge quality of the wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figure 1 According to one aspect of the present invention, a method for recovering and treating sodium saccharin wastewater is provided, comprising the following steps:

[0033] Step 1: inject the wastewater into the sedimentation tank to precipitate large particles, and then use the filtering equipment to filter the floating particles in the wastewater;

[0034] Step 2: Purify the wastewater by neutralization, oxidation and flocculation in sequence; the neutralization method in this step adjusts the wastewater to neutrality by adding acid or alkali according to the pH value of the wastewater. The oxidation method uses chemical oxidants to remove organic matter and other pollutants; the chemical oxidants include chlorine, hydrogen peroxide or ozone. The flocculation method adds flocculants to aggregate small particles into larger particles for sedimentation; the flocculants include polyaluminium chloride and polyferric sulfate.

[0035] Step 3: Using activated sludge containing microorganisms in a bioreactor to degrade organic matter in the wastewater, and using anaerobic bacteria to degrade high-sugar components in the wastewater;

[0036] Step 4: performing secondary precipitation on the treated wastewater;

[0037] Step 5: Combining light and catalyst to carry out photocatalytic oxidation, and using ozone to oxidize the refractory organic matter in the wastewater;

[0038] Step 6: Chlorination disinfection of the treated wastewater;

[0039] Step 7: The disinfected wastewater is safely discharged after it reaches the safe discharge standard.

[0040] In this embodiment, the wastewater in step 4 is subjected to secondary precipitation after chemical treatment and biological treatment, and the supernatant after wastewater precipitation is monitored. By sequentially subjecting the sodium saccharin wastewater to chemical, biological, photocatalytic and ozone oxidation treatments, high sugar, organic floating matter and other soluble impurities in the sodium saccharin wastewater can be aggregated and treated in an all-round manner.

[0041] Example 2

[0042] According to the concentration of sodium saccharin, the total amount of bacteria and the conductivity in the supernatant, the qualified coefficient of the liquid after the secondary precipitation is determined as follows:

[0043]

[0044] in, Indicates the qualified coefficient of the liquid after secondary precipitation, represents the conductivity of the liquid, Indicates the concentration of saccharin sodium in the supernatant. Indicates the total amount of bacteria in the supernatant; and has:

[0045]

[0046] In the formula, represents the conductivity of the liquid, Indicates the current size of the electrode in the clear solution. Indicates the voltage of the electrode in the clear solution. represents the temperature coefficient, Indicates the standard temperature size, Indicates the measured temperature.

[0047] when When , it means that the liquid of saccharin sodium wastewater after secondary precipitation initially meets the requirements;

[0048] when When , it means that the liquid after the secondary precipitation of sodium saccharin wastewater does not meet the requirements. At this time, the wastewater needs to re-enter step three for treatment.

[0049] The conductivity of the wastewater is measured once, and the current value of the electrode connected to the clear liquid is measured. (ampere), the voltage of the electrode in the clear solution is (V), the temperature coefficient is , standard temperature size (℃), the measured temperature is (℃), then:

[0050]

[0051] From the above calculation, we can know that the conductivity of the liquid is .

[0052] Among them, the concentration of saccharin sodium in the supernatant was (mg / L), the total amount of bacteria in the supernatant was ( CFU / g). Then, the qualified coefficient of the liquid after secondary precipitation is:

[0053]

[0054] From the above calculations, it can be seen that the liquid from the sodium saccharin wastewater after secondary sedimentation initially meets the requirements.

[0055] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for recycling and treating sodium saccharin wastewater, characterized in that: The following steps are involved: S1. Pour wastewater into a sedimentation tank to precipitate large particles, and then use filtering equipment to filter floating particles in the wastewater; S2, purifying the wastewater by neutralization, oxidation and flocculation in sequence; S3. Use active sludge containing microorganisms in a bioreactor to degrade organic matter in wastewater, and use anaerobic bacteria to degrade organic matter in wastewater with high sugar content; S4, performing secondary precipitation on the treated wastewater; S5, combining light and catalyst for photocatalytic oxidation, and using ozone to oxidize the refractory organic matter in the wastewater; S6. Chlorination disinfection of treated wastewater; S7. After the disinfected wastewater reaches the safe discharge standard, it shall be discharged safely; In step S4, the wastewater is subjected to secondary precipitation after chemical treatment and biological treatment, and the supernatant after the wastewater precipitation is monitored; According to the concentration of sodium saccharin, the total amount of bacteria and the conductivity in the supernatant, the qualified coefficient of the liquid after the secondary precipitation is determined as follows: Wherein, C represents the qualified coefficient of the liquid after secondary precipitation, s represents the conductivity of the liquid, g represents the concentration of saccharin sodium in the supernatant, and a represents the total amount of bacteria in the supernatant; and: In the formula, s represents the conductivity of the liquid, I represents the current of the electrode connected to the clear liquid, V represents the voltage of the electrode connected to the clear liquid, k represents the temperature coefficient, T0 represents the standard temperature, and T represents the measured temperature; When C ≥ 82%, it means that the liquid of saccharin sodium wastewater after secondary precipitation initially meets the requirements; When C is less than 82%, it means that the liquid after the secondary precipitation of the sodium saccharin wastewater does not meet the requirements, and the wastewater needs to be re-entered into step S3 for treatment.

2. The method for recycling sodium saccharin wastewater according to claim 1, characterized in that: The neutralization method in step S2 adjusts the wastewater to neutrality by adding acid or alkali according to the pH value of the wastewater.

3. The method for recycling saccharin sodium wastewater according to claim 2, characterized in that: The oxidation method in step S2 uses a chemical oxidant to remove organic matter and other pollutants; wherein the chemical oxidant includes chlorine, hydrogen peroxide or ozone.

4. The method for recycling sodium saccharin wastewater according to claim 3, characterized in that: The flocculation method in step S2 is to add a flocculant to aggregate small particles into larger particles for sedimentation; wherein the flocculant includes polyaluminium chloride and polyferric sulfate.

5. The method for recycling saccharin sodium wastewater according to claim 1, characterized in that: The photocatalytic oxidation in step S5 utilizes high-energy electrons and holes generated by photocatalysts under light conditions to react with pollutants to degrade and remove pollutants; The photocatalyst comprises titanium dioxide and zinc oxide.

6. The method for recycling saccharin sodium wastewater according to claim 1, characterized in that: The ozone oxidation in step S5 utilizes ozone to react with pollutants in water to form hydrogen peroxide and hydroxyl radicals.

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