Treatment system and method for organic chlorine-containing pharmaceutical wastewater

Abstract

The invention discloses a system and a method for treating organic chlorine-containing pharmaceutical wastewater. The method comprises the following steps: feeding high-concentration organic chlorine-containing pharmaceutical wastewater into a high-concentration collecting tank for average value and average quantity adjustment; the adjusted wastewater sequentially enters a triple-effect evaporator, a condensate tank, an iron-carbon micro-electrolysis tank and an electric flocculation air flotation device; low-concentration wastewater is adjusted by a low-concentration collecting tank and then mixed with effluent of the air floatation tank in an anaerobic water distribution tank, and the effluent sequentially enters a UASB anaerobic tank, a hydrolysis acidification tank, a two-stage O / A system, a secondary sedimentation tank, a physicochemical reaction tank and a physicochemical sedimentation tank and then is discharged after reaching the standard. According to the method, triple-effect evaporation gradient parameters are optimized, an iron-carbon micro-electrolysis and high-voltage pulse electric flocculation air flotation combined mechanism is enhanced, and a precise water distribution regulation strategy is combined, so that the toxic load of a subsequent biochemical system is effectively reduced, and the overall treatment efficiency and impact resistance are improved.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a system and method for treating organic chlorine-containing pharmaceutical wastewater. Background Technology

[0002] In the synthesis and production of pharmaceutical intermediates, various organic solvents, halogenated reagents, strong acids and bases, and metal catalysts are widely used, resulting in process wastewater with the following distinct characteristics: extremely high chemical oxygen demand (COD) concentration (usually above 80,000 mg / L), high salt content (total dissolved solids (TDS) often exceeds 30,000 mg / L, and chloride ion concentration can reach over 20,000 mg / L), complex and variable composition (often containing aromatic compounds, halogenated hydrocarbons, pyridines, alcohols, ethers, esters, and other organic substances), and containing a large amount of substances that inhibit or toxicize microorganisms. The biodegradability (BOD5 / COD, B / C ratio) of this type of wastewater is typically below 0.3, classifying it as typical recalcitrant wastewater.

[0003] Currently, the common process route for treating this type of wastewater is "pretreatment + biological treatment". Pretreatment methods mainly include evaporative desalination: such as multi-effect evaporation (MEE) or mechanical vapor recompression (MVR). Although evaporative desalination can effectively remove inorganic salts, the condensate is still rich in a large amount of low-boiling-point volatile organic compounds (VOCs) and some high-boiling-point recalcitrant organic compounds, which will cause a shock if directly introduced into the biological treatment system. Advanced oxidation processes (AOPs): such as Fenton oxidation, ozone oxidation, and wet catalytic oxidation, can effectively destroy the structure of recalcitrant organic compounds and improve biodegradability, but they generally have problems such as high reagent consumption, high operating costs, and may also produce secondary pollution such as iron sludge. For chlorinated wastewater, they may also produce toxic halogenated byproducts. Micro-electrolysis technology: uses iron-carbon galvanic cell reaction to reduce and break down organic compounds, but long-term operation is prone to caking, requires frequent pH adjustment, and exacerbates iron loss in high-salt wastewater. Biochemical treatment often employs a combination of anaerobic (such as UASB, IC) and aerobic (such as A / O, SBR) processes.

[0004] Current technical solutions often treat physicochemical pretreatment and biological treatment as a fixed series process, lacking flexibility to cope with fluctuations in influent water quality. When the pretreated effluent has poor biodegradability, it directly leads to a decrease in the efficiency of subsequent biological systems or even paralysis. In addition, given the unique bioinhibitory properties of pharmaceutical wastewater, single anaerobic or aerobic units are often difficult to operate stably, requiring more precise control of the microbial metabolic environment.

[0005] Therefore, developing a treatment system and method for organic chlorine-containing pharmaceutical wastewater that can intelligently adapt to changes in water quality, achieve high efficiency and synergy, and has controllable operating costs is of great significance for solving the problem of treating high-concentration organic pharmaceutical wastewater. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a treatment system and method for organic chlorine-containing pharmaceutical wastewater. It optimizes the triple-effect evaporation gradient parameters, enhances the combined mechanism of iron-carbon micro-electrolysis and high-voltage pulse electrocoagulation-air flotation, and combines precise water distribution and control strategies to effectively reduce the toxicity load of subsequent biochemical systems, improve overall treatment efficiency and shock resistance, and solves the core pain points of high-concentration organic chlorine-containing pharmaceutical wastewater, such as chloride toxicity inhibition, recalcitrant degradation of organic chlorine, and equipment corrosion.

[0007] To address the aforementioned technical problems, this invention provides a method for treating organic chlorine-containing pharmaceutical wastewater, comprising the following steps:

[0008] S1. High-concentration organic chlorine-containing pharmaceutical wastewater enters the high-concentration collection tank for average quantity adjustment;

[0009] S2. The adjusted wastewater enters a triple-effect evaporator for gradient evaporation and desalination. The secondary steam is condensed and then enters the condensate tank. The condensate tank monitors COD and B / C online. When COD ≤ 16000 mg / L and B / C ≥ 0.4, it directly enters the S5 anaerobic water distribution tank. When COD > 16000 mg / L or B / C < 0.4, it enters the S3 iron-carbon micro-electrolysis cell.

[0010] S3. The effluent from the condensate pool enters the iron-carbon micro-electrolysis cell to react and convert organic chlorine into easily biodegradable small molecule organic acids.

[0011] S4. The effluent from the iron-carbon micro-electrolysis cell enters the electrocoagulation and flotation device to separate suspended solids and colloidal substances.

[0012] S5. After being regulated in the low-concentration collection tank, the low-concentration wastewater is mixed with the effluent from the flotation tank and / or the effluent from the condensate tank in the anaerobic water distribution tank to adjust the pH and supplement nitrogen and phosphorus nutrients, thus forming suitable conditions for anaerobic digestion.

[0013] S6. The effluent from the anaerobic water distribution tank sequentially enters the UASB anaerobic tank, the hydrolysis acidification tank, and the two-stage O / A system to achieve the biodegradation of organic matter and nitrogen, and then enters the secondary sedimentation tank.

[0014] S7. The effluent from the secondary sedimentation tank enters the physicochemical reaction tank for deep phosphorus removal and turbidity reduction, and then passes through the physicochemical sedimentation tank before being discharged in compliance with standards.

[0015] Furthermore, in the high-concentration organic chlorine-containing pharmaceutical wastewater, the chloride concentration is ≥10000 mg / L, COD ≥50000 mg / L, and B / C ratio ≤0.3. The pH of the high-concentration collection tank is adjusted to 4.0-4.5, as acidic wastewater corrodes the TA2 heat exchange tubes of the subsequent triple-effect evaporator. The pH of the low-concentration wastewater (COD ≤2000 mg / L) is adjusted to 6-9.

[0016] Furthermore, in the triple-effect evaporator, the first effect temperature is 90-100℃ and the vacuum degree is -0.04±0.005MPa; the second effect temperature is 70-80℃ and the vacuum degree is -0.06±0.005MPa; and the third effect temperature is 50-60℃ and the vacuum degree is -0.08±0.005MPa.

[0017] And / or, the pH of the inlet water for the triple-effect evaporator is 4.0-4.5, and the chloride ion concentration in the secondary steam condensate is ≤300mg / L;

[0018] And / or, when the pressure in the discharge pipeline increases by 10%, the hot water + dilute alkali solution cleaning program is automatically started, and the crystallized salt is dehydrated by centrifuge to a moisture content of ≤10%.

[0019] Furthermore, in the iron-carbon microelectrolysis cell, the iron-carbon packing particle size is 3-5mm, the iron-carbon ratio is (2.8-3.2):1, the pH is 2.8-4.0, the residence time is 1.5-2h, the organic chlorine chain scission efficiency is ≥40%, and the effluent B / C ratio is ≥0.4.

[0020] Furthermore, the conditions for the electrocoagulation flotation device are: pulse current 80-100A, pulse frequency 45-55Hz, voltage 25-35V, dissolved air pressure 0.5-0.6MPa, and PAC flow rate in the flotation zone 0.13kg / m³. 3 PAM flow rate 0.008 kg / m³ 3 .

[0021] Furthermore, the anaerobic water distribution tank adjusts the pH value of the wastewater to 7.0±0.3; wherein, the low-concentration wastewater and the pretreated effluent (effluent from the flotation tank and condensate tank) are mixed at a ratio of (3.5-4.5):1 to ensure that the COD of the mixed solution is ≤6000mg / L.

[0022] Furthermore, the UASB anaerobic tank is inoculated with chloride-tolerant anaerobic granular sludge acclimated to a chloride gradient of 1000-5000 mg / L, with an alkalinity of 2000-3000 mg / L (calculated as CaCO3) and a COD removal rate of ≥58%.

[0023] Furthermore, the UASB anaerobic tank has a retention time of ≥4 days; the hydrolysis acidification tank has a retention time of ≥3 days, and is equipped with built-in elastic three-dimensional packing material.

[0024] The switchable process of this invention precisely adapts to fluctuations in the quality of chlorinated wastewater, avoiding redundant operations and the risk of substandard treatment. By monitoring the COD and B / C ratio of the condensate online, when COD ≤ 16000 mg / L and B / C ≥ 0.4, the bypass is opened to directly enter the biological system, reducing the consumption of reagents for iron-carbon micro-electrolysis and electrocoagulation; when COD > 16000 mg / L or B / C < 0.4, the bypass is closed and enhanced pretreatment is initiated to ensure sufficient chain breaking of organochlorine compounds. This switching logic addresses the changes in chloride and organochlorine concentrations (fluctuation range ±30%) caused by batch fluctuations in pharmaceutical production, maintaining a compliance rate of over 99% for effluent COD ≤ 450 mg / L and chloride < 500 mg / L, reducing operating costs by 15-20% compared to traditional fixed-process technology.

[0025] This invention addresses the chloride toxicity of chlorine-containing wastewater by constructing a synergistic system of "pretreatment deep dechlorination + biochemical chloride tolerance acclimation." A triple-effect evaporator achieves highly efficient separation of salts and chloride ions (chloride removal rate ≥98.5%) through precise control of pH 4.0-4.5 and low-temperature, high-vacuum parameters, avoiding the inhibition of subsequent biochemical microorganisms by high chlorine levels. Simultaneously, the UASB anaerobic tank is inoculated with granular sludge (VSS / SS=0.7) acclimated to a chloride gradient of 1000-5000 mg / L. By gradually increasing the influent chloride concentration over an acclimation period of 15-20 days, the sludge's chloride tolerance concentration is increased from the conventional 200 mg / L to over 800 mg / L, solving the problem of COD removal rates below 30% in traditional anaerobic systems due to chloride toxicity.

[0026] Simultaneously, this invention constructs a pretreatment-biochemical coupling mechanism of "directional chain scission of organochlorine compounds + synergistic biochemical degradation" for wastewater with a B / C ratio of <0.4 or COD >16000 mg / L. For recalcitrant organochlorine compounds such as sorbitol and chloropyridine in chlorinated wastewater, the iron-carbon microelectrolysis reactor utilizes the nascent Fe generated by the micro-battery reaction. 2+ By breaking the C-Cl bond with [H] (chain breaking efficiency ≥40%), recalcitrant organochlorine is converted into easily biodegradable small-molecule organic acids. The subsequent high-voltage pulse electrocoagulation flotation device uses titanium-coated ruthenium electrodes (resistant to chlorine corrosion) to further oxidize residual organochlorine under conditions of 80-100A current and 45-55Hz pulse frequency, increasing the B / C ratio of the condensate from ≤0.3 to ≥0.4, laying the foundation for subsequent biochemical degradation. This synergistic mechanism improves the removal rate of organochlorine by more than 30% compared with the traditional Fenton oxidation, and reduces the reagent cost by 25%.

[0027] Furthermore, the two-stage O / A system includes a first-stage denitrification tank, a first-stage nitrification tank, a second-stage denitrification tank, and a second-stage nitrification tank connected in sequence; wherein, the first-stage denitrification tank controls DO ≤ 0.5 mg / L, the first-stage nitrification tank has DO 2-3 mg / L, sodium carbonate is added to supplement alkalinity, and the nitrification liquor reflux ratio is 200~300%; the second-stage denitrification tank has DO ≤ 0.5 mg / L, the second-stage nitrification tank has DO 2~3 mg / L, MLSS 3000~4000 mg / L, and the second-stage nitrification liquor reflux ratio is 50~100%; when the COD of the influent to the first-stage nitrification tank is ≥ 3000 mg / L, the monitoring tank effluent reflux pump is automatically started to dilute the influent at a 1:1 ratio.

[0028] Furthermore, PAC and PAM are added to the physicochemical reaction tank. Preferably, the physicochemical reaction tank is divided into two compartments, with the first compartment having a stirrer speed of 100-150 r / min and the second compartment having a stirrer speed of 30-50 r / min, where 10% PAC (0.1 kg / m³) is added. 3 ) and 0.1% PAM (0.003 kg / m 3 The surface loading of the physicochemical sedimentation tank is 0.42 m. 3 / (m 2 •h), retention time 3-5h, effluent from physicochemical sedimentation tank passes through monitoring tank, equipped with online monitoring instruments for COD, TN and ammonia nitrogen, connected to the environmental protection department, and wastewater exceeding the standard is automatically returned to anaerobic water distribution tank.

[0029] Furthermore, the effluent quality that meets the discharge standards satisfies the following requirements: COD ≤ 450 mg / L, ammonia nitrogen ≤ 30 mg / L, total nitrogen ≤ 40 mg / L, toluene ≤ 0.2 mg / L, and chloride ≤ 500 mg / L.

[0030] The second aspect of the present invention provides a treatment system for organic chlorine-containing pharmaceutical wastewater to implement the treatment method described in the first aspect. The system includes a high-concentration collection tank, a triple-effect evaporator, a condensate tank, an iron-carbon micro-electrolysis tank, an electrocoagulation tank, an air flotation tank, an anaerobic water distribution tank, a UASB anaerobic tank, a hydrolysis acidification tank, a two-stage O / A system, a secondary sedimentation tank, a physicochemical reaction tank, and a physicochemical sedimentation tank, which are connected in sequence. The condensate tank and the anaerobic water distribution tank are connected by pipelines, and the anaerobic water distribution tank is also connected to a low-concentration collection tank.

[0031] The beneficial effects of this invention are:

[0032] The switchable process of this invention is precisely adapted to the fluctuations in the water quality of chlorinated wastewater, avoiding redundant operations and the risk of substandard treatment. In response to the chloride toxicity of chlorinated wastewater, a synergistic system of "pretreatment deep dechlorination + biochemical chlorine tolerance acclimatization" is constructed. For wastewater with B / C < 0.4 or COD > 16000 mg / L, a pretreatment-biochemical coupling mechanism of "organic chlorine directional chain scission + biochemical synergistic degradation" is constructed.

[0033] This invention utilizes a tiered treatment system of "desalination - directional chain breaking of organic chlorine - chlorine-resistant biochemical degradation - precise end-of-pipe treatment" to achieve precise targeted removal of salts, organic chlorine, and conventional organic matter. The total COD removal rate can reach over 99.7%, and the total chloride removal rate is ≥98.85%. The final effluent has COD ≤450mg / L, ammonia nitrogen ≤30mg / L, total nitrogen ≤40mg / L, toluene ≤0.2mg / L, and chloride ≤500mg / L. The treatment effect is stable and reliable with no risk of secondary pollution. Attached Figure Description

[0034] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the process for treating organic chlorine-containing pharmaceutical wastewater according to the present invention. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This embodiment provides a method for treating organic chlorine-containing pharmaceutical wastewater. The wastewater is from the production of betostine benzyl sulfonate intermediates, with key water quality indicators: COD 150,000 mg / L, chloride 24,000 mg / L, toluene 20 mg / L, containing p-bromochlorobenzene derivative 500 mg / L, B / C ratio 0.28, and pH 1.69. It belongs to typical high-concentration organic chlorine-containing pharmaceutical wastewater. The water quality and quantity of the production process in this embodiment are shown in Table 1.

[0038] Table 1

[0039]

[0040] Reference Figure 1As shown, this embodiment employs a tiered treatment route of "separate pretreatment + mixed biological treatment + end-of-pipe physicochemical assurance" for three types of wastewater: First, triple-effect evaporation + electrochemical oxidation are used to break down recalcitrant organic matter and separate salts in high-salt, high-concentration wastewater; then, after mixing with low-concentration wastewater, COD is deeply degraded and denitrified through UASB anaerobic treatment + two-stage A / O aerobic treatment; finally, physicochemical sedimentation ensures that the effluent meets standards. The entire process achieves a reduction from a high COD of 150,000 mg / L to below 450 mg / L through precise control of pH, temperature, DO (dissolved oxygen), and reagent dosage. The specific process description is as follows:

[0041] (1) High-concentration wastewater and medium-concentration wastewater enter the high-concentration collection tank for equalization and pH adjustment to 4.0-4.5.

[0042] (2. The adjusted wastewater enters a triple-effect evaporator for gradient evaporation and desalination. The secondary steam condenses and enters a condensate tank. The temperature of the first effect is 100℃ and the vacuum degree is -0.04MPa; the temperature of the second effect is 80℃ and the vacuum degree is -0.06MPa; and the temperature of the third effect is 60℃ and the vacuum degree is -0.08MPa. The live steam first enters the first-effect heating unit to heat the wastewater to a specific temperature, causing low-boiling-point organic compounds such as tetrahydrofuran and methanol to escape with the secondary steam. After condensation, the wastewater enters the wastewater treatment system. The remaining brine sequentially enters the second-effect and third-effect heating units. By gradually reducing the temperature and adjusting the vacuum degree, the salts are precipitated in the final unit. According to the company's requirements, in this embodiment, low-boiling-point pollutants are not recycled. Instead, the vacuum degree of the wastewater is adjusted so that the low-boiling-point substances are in the liquid phase and enter the wastewater treatment system.)

[0043] (3) The effluent from the condensate pool enters the iron-carbon micro-electrolysis cell for reaction, where broken-chain cyclic and long-chain recalcitrant organic matter is converted into easily biodegradable small-molecule organic acids; wherein the iron-carbon filler has a particle size of 3-5 mm, an iron-carbon ratio of 3:1, a pH of 3.0±0.2, and a residence time of 1.5 h.

[0044] (4) The effluent from the iron-carbon micro-electrolysis cell enters the electrocoagulation and flotation device to separate suspended solids and colloidal substances; wherein, the pulse current is 90A, the pulse frequency is 50Hz, the voltage is 30V, the dissolved air pressure is 0.6MPa, and the PAC flow rate in the flotation zone is 0.13kg / m³. 3 PAM flow rate 0.008 kg / m³ 3 .

[0045] (5) After being regulated in the low-concentration collection tank, the low-concentration wastewater is mixed with the effluent from the flotation tank in the anaerobic water distribution tank, the pH is adjusted to 7.0 and nitrogen and phosphorus nutrients are added to form the conditions for anaerobic digestion.

[0046] (6) The effluent from the anaerobic distribution tank sequentially enters the UASB anaerobic tank, the hydrolysis acidification tank, and the two-stage O / A system to achieve the biodegradation of organic matter and nitrogen, and then enters the secondary sedimentation tank. Specifically, in the UASB anaerobic tank, 180m³ of water is inoculated. 3 Chlorine-tolerant anaerobic granular sludge (VSS / SS=0.7) acclimated to a chloride gradient of 1000-5000 mg / L, with an alkalinity of 2500 mg / L (calculated as CaCO3), under mesophilic conditions of 35-38℃ and pH 7.0-7.5, methanogenic and acidogenic bacteria decompose macromolecular organic matter (such as long-chain fatty acids and aromatic compounds) into smaller molecules such as methane and acetic acid, significantly reducing COD and further improving the biodegradability of wastewater, laying the foundation for subsequent aerobic treatment; the retention time in the UASB anaerobic tank is 4 days. The retention time in the hydrolysis acidification tank is 3 days. The two-stage O / A system consists of a first-stage denitrification tank, a first-stage nitrification tank, a second-stage denitrification tank, and a second-stage nitrification tank connected in sequence. In the first-stage denitrification tank, the DO is controlled to be ≤0.5 mg / L, and the DO in the first-stage nitrification tank is 2-3 mg / L. Sodium carbonate is added to supplement alkalinity, and the nitrification liquor reflux ratio is 200%. In the second-stage denitrification tank, the DO is ≤0.5 mg / L, and the DO in the second-stage nitrification tank is 2~3 mg / L, with MLSS of 3000 mg / L. The nitrification liquor reflux ratio in the second-stage nitrification tank is 50%.

[0047] (7) The effluent from the secondary sedimentation tank enters the physicochemical reaction tank for deep phosphorus removal and turbidity reduction; the physicochemical reaction tank is divided into two compartments, the first compartment has a stirrer speed of 100 r / min, and the second compartment has a stirrer speed of 30 r / min, with 10% PAC (0.1 kg / m³) added. 3 ) and 0.1% PAM (0.003 kg / m 3 The surface loading of the physicochemical sedimentation tank is 0.42 m. 3 / (m 2 •h), residual organic matter is precipitated and separated under pH 7.0-7.5 conditions with a residence time of 4 hours; subsequently, it is discharged after passing through a physicochemical sedimentation tank and meeting discharge standards. The removal rates of each unit in the wastewater treatment process are shown in Table 2.

[0048] Table 2

[0049]

[0050] This embodiment, after 30 days of continuous operation, showed effluent COD fluctuations of 380-400 mg / L, chloride of 260-280 mg / L, and toluene of 0.08-0.1 mg / L, achieving a 100% compliance rate with no biological system collapse. Compared to the traditional "Fenton oxidation + conventional A / O" process, this process increases organic chlorine removal rate by 32%, chloride removal rate by 15%, and reduces operating costs by 22% (traditional process cost 85 yuan per ton of water, this process cost 66.43 yuan), and eliminates secondary pollution from iron sludge.

[0051] In summary, the switchable process of this invention is precisely adapted to fluctuations in the water quality of chlorinated wastewater, avoiding redundant operations and the risk of substandard treatment. Addressing the chloride toxicity of chlorinated wastewater, a synergistic system of "pretreatment deep dechlorination + biochemical chlorine tolerance acclimation" is constructed. For wastewater with B / C < 0.4 or COD > 16000 mg / L, a pretreatment-biochemical coupling mechanism of "directional organochlorine chain breaking + biochemical synergistic degradation" is constructed. Through a stepped, graded treatment system of "desalination - directional organochlorine chain breaking - chlorine-tolerant biochemical degradation - precise end-of-pipe treatment," precise targeted removal of salts, organochlorines, and conventional organic matter is achieved. The total COD removal rate can reach over 99.7%, and the total chloride removal rate is ≥ 98.85%. The final effluent has COD ≤ 450 mg / L, ammonia nitrogen ≤ 30 mg / L, total nitrogen ≤ 40 mg / L, toluene ≤ 0.2 mg / L, and chloride ≤ 500 mg / L, with stable and reliable treatment effects and no risk of secondary pollution.

[0052] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for treating organic chlorine-containing pharmaceutical wastewater, characterized in that, Includes the following steps: S1. High-concentration organic chlorine-containing pharmaceutical wastewater enters the high-concentration collection tank for average quantity adjustment; S2. The adjusted wastewater enters a triple-effect evaporator for gradient evaporation and desalination. The secondary steam is condensed and then enters the condensate tank. The condensate tank monitors COD and B / C online. When COD ≤ 16000 mg / L and B / C ≥ 0.4, it directly enters the S5 anaerobic water distribution tank. When COD > 16000 mg / L or B / C < 0.4, it enters the S3 iron-carbon micro-electrolysis cell. S3. The effluent from the condensate pool enters the iron-carbon micro-electrolysis cell to react and convert organic chlorine into easily biodegradable small molecule organic acids. S4. The effluent from the iron-carbon micro-electrolysis cell enters the electrocoagulation and flotation device to separate suspended solids and colloidal substances. S5. After being regulated in the low-concentration collection tank, the low-concentration wastewater is mixed with the effluent from the flotation tank and / or the effluent from the condensate tank in the anaerobic water distribution tank to adjust the pH and supplement nitrogen and phosphorus nutrients, thus forming suitable conditions for anaerobic digestion. S6. The effluent from the anaerobic water distribution tank sequentially enters the UASB anaerobic tank, the hydrolysis acidification tank, and the two-stage O / A system to achieve the biodegradation of organic matter and nitrogen, and then enters the secondary sedimentation tank. S7. The effluent from the secondary sedimentation tank enters the physicochemical reaction tank for deep phosphorus removal and turbidity reduction, and then passes through the physicochemical sedimentation tank before being discharged in compliance with standards.

2. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, The high-concentration organic chlorine-containing pharmaceutical wastewater has a chloride concentration ≥10000 mg / L, COD ≥50000 mg / L, and B / C ratio ≤0.

3.

3. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, In the triple-effect evaporator, the first effect temperature is 90-100℃ and the vacuum degree is -0.04±0.005MPa; the second effect temperature is 70-80℃ and the vacuum degree is -0.06±0.005MPa; and the third effect temperature is 50-60℃ and the vacuum degree is -0.08±0.005MPa. And / or, the pH of the inlet water for the triple-effect evaporator is 4.0-4.5, and the chloride ion concentration in the secondary steam condensate is ≤300mg / L.

4. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, In the iron-carbon microelectrolysis cell, the iron-carbon packing particle size is 3-5mm, the iron-carbon ratio is (2.8-3.2):1, the pH is 2.8-4.0, the residence time is 1.5-2h, the organic chlorine chain scission efficiency is ≥40%, and the effluent B / C ratio is ≥0.

4.

5. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, The conditions for the electrocoagulation flotation device are: pulse current 80-100A, voltage 25-35V, and dissolved gas pressure 0.5-0.6MPa.

6. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, The anaerobic water distribution tank is used to adjust the pH of the wastewater to 7.0 ± 0.

3.

7. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, The UASB anaerobic tank is inoculated with chloride-tolerant anaerobic granular sludge acclimated to a chloride gradient of 1000-5000 mg / L, with an alkalinity of 2000-3000 mg / L and a COD removal rate of ≥58%.

8. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, PAC and PAM are added to the physicochemical reaction tank.

9. The method for treating organic chlorine-containing pharmaceutical wastewater as described in claim 1, characterized in that, The effluent quality that meets the discharge standards is COD≤450mg / L, ammonia nitrogen≤30mg / L, total nitrogen≤40mg / L, toluene≤0.2mg / L, and chloride≤500mg / L.

10. A treatment system for organic chlorine-containing pharmaceutical wastewater, characterized in that, The method for implementing the treatment method according to any one of claims 1-9 includes a high-concentration collection tank, a triple-effect evaporator, a condensate tank, an iron-carbon micro-electrolysis tank, an electrocoagulation tank, an air flotation tank, an anaerobic water distribution tank, a UASB anaerobic tank, a hydrolysis acidification tank, a two-stage O / A system, a secondary sedimentation tank, a physicochemical reaction tank, and a physicochemical precipitation tank, which are connected in sequence. The condensate tank and the anaerobic water distribution tank are provided with connecting pipelines, and the anaerobic water distribution tank is also connected to a low-concentration collection tank.

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