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Application Of Polyacrylamide In Oil Exploitation

Application of polyacrylamide in oil exploitationPolyacrylamide(PAM) can widely use in more area,such as papermaking dispersant,incense making ,oil industry etc..Here we will make a introduction about pam using in oil industry.In oil extraction, polyacrylamide can be used as thickening agent, stabilizer and settling flocculant in drilling mud; adding polyacrylamide in tertiary oil recovery can increase oil displacement and enhance oil recovery; Fracturing fluid additives, retarder, water and oil ratio control agent, temporary plugging agent.The follows are attentions of polyacrylamide in the applications:1. granular polyacrylamide flocculant can not be directly added to the sewage. Before use it must be dissolved in water, with its aqueous solution to deal with sewage.2. dissolved granular polyacrylamide water should be clean (such as tap water), can not be sewage. Normal temperature water can, generally do not need heating. Water temperature below 5 ℃ when dissolved very slowly. Water temperature increased dissolution speed, but more than 40 ℃ will accelerate the degradation of polymers, affecting the results. General tap water is suitable for formulating polymer solutions. Strong acid, alkali, high salt water are not suitable for the preparation. In this case,3. the choice of polymer solution concentration, the US source of 0.1% -0.3%, that is, 1 liter of water plus 1g-3g polyacrylamide powder.Polyacrylamide concentration to consider the following factors:A. Preparation of small pots of daily dosage, it is recommended with a little thicker (such as 0.3%). When the molecular weight of the polymer is high, it is recommended to use a slightly thinner (eg 0.1%). In this case,B. Polyacrylamide solution into the sewage, such as due to equipment scattered state is not very good, the proposed distribution of a little thinner. In short, the polymer concentration is too large, will cause the stirrer motor load is too large, will result in poor state of dispersion into the sewage, affecting the results. With a thin some help to improve the use of results. In this case,4. dubbed the solution do not use centrifugal pump transfer, so as not to cause high-speed rotation of the blade polyacrylamide polymer shear degradation. Preparation of the specific methods are as follows: in the solvent (such as the laboratory beaker, factory preparation tank) by adding a certain amount of water, according to the amount of water and concentration calculation of the amount of powder polymer, weighed polyacrylamide polymer.
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Introductions Of Commonly Antioxidant

There are many kinds of rubber antioxidant, different role. Its main purpose is to inhibit the aging of rubber, prolong the service life of rubber products, more and more used in the tire industry, rubber products and other industriesAntioxidant D: Antioxidant D is universal antioxidant ,widely use for natural rubber, synthetic rubber. It has a good protective effect on heat, oxygen, bending cracking and general aging factors.Antioxidant RD and antioxidant 124: The antioxidant RD and the antioxidant 124 are composed of the same chemical ingredient except that the antioxidant RD is resinous and the antioxidant 124 is in the form of powder and the antioxidant RD is amber to off-white resin Powder, non-toxic. Softening point of not less than 74 ℃. The antioxidant 124 was an off-white powder with a melting point of 114 ° C. Antioxidant RD and antioxidant 124 soluble in acetone, benzene, chloroform, carbon disulfide; slightly soluble in petroleum hydrocarbons, do not dissolve in water. Contaminated but not significant. Difficult to spray frost, no effect on the vulcanization. Combustible, non-toxic. Applicable to natural rubber and styrene butadiene, such as synthetic rubber eyesight, the amount is generally 0.5 to 3 copies.Due to the role of each of the protective effects of antioxidants are limited, and the actual use of rubber products in the aging is affected by a variety of factors,Therefore, in the choice of anti-aging agent must be clear the use of anti-aging agents and formulations.
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How To Choose Polyacrylamide In Diffierent Industry

As we all know, Polyacrylamide(PAM) also named industry additives, It is widely used in sewage treatment. But it is not a panacea, not a model can solve all the problems, all the different sewage treatment standards, different sewage needs to use the corresponding product, there is a problem how to choose the appropriate flocculant? Here we will give you an introduction for this question. The nature of sewage produced by different enterprise,some are acidic water, alkaline water and some water, is neutral, some contain oil, some contain large amounts of organic matter, containing some color, some contain large amounts of sediment, as well as a variety of circumstances, nature of sewage have different situation. In general,Cationic Polyacrylamide has a good effect on acidic sewage,anionic polyacrylamide has a good effect on alkaline sewage.Of course, the water quality of neutral sewage is relatively alkaline and acidic sewage is easy to deal with, if the acidic water quality of sewage is too large, is generally difficult to handle, the usual approach is to add alkali to the sewage, adjust the pH of the sewage, so that Sewage to neutral the best. So the most easy to deal with, but also can save processing costs. Conversely, if the sewage showed alkaline strength, it is necessary to add acid to adjust the pH of the sewage. Sewage is neutral, not the kind of polyacrylamide can be the sewage treatment is good, to discharge standards, which have a more accurate selection problem, the usual practice is to do a small test in the laboratory, through Repeated experiments, select the best experimental model, and then in the actual production process to test whether the selected models in production is also appropriate.
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Applications Of Polyacrylamide

Polyacrylamide (PAM)is the polymer of acrylamide monomer homopolymerization or copolymerization under the action of initiator. It is one of the most widely used water-soluble polymer materials. It is mainly used in petroleum exploitation, water treatment, Textile, paper, mineral processing, medicine, agriculture and other industries.The Applications of Polyacrylamide :1.Mainly used as flocculant for suspended particles, coarse, high concentration, particle with positive charge, water pH value is neutral or alkaline water, because of solid particles of anionic polyacrylamide molecular chain containing a certain amount of polar suspension can absorb water, make the bridge between particles into large flocs. It accelerated the suspension the settlement of particles have obvious to speed up the solution of clarification, promote the filtering effect. The products are widely used in chemical industrial wastewater, wastewater treatment, municipal sewage treatment industry. Tap water, purification, high turbidity water cleaning, washing, dressing, metallurgy, steel, zinc, aluminum processing, electronic water treatment industrial etc.2.Polyacrylamide used in the oil industry, oil production, drilling mud, waste mud treatment, prevent water channeling, reduce friction, improve oil recovery, three oil extraction has been widely used.3.Polyacrylamide for textile sizing agent, sizing performance-stability, falls-pulp less, fabric breakage rate is low, clean cloth.4.Polyacrylamide used in the papermaking industry, one is to improve the packing, pigmentretention rate. In order to reduce the loss of raw materials and pollution to the environment; the two is to improve the strength of paper (including dry and wet strength), in addition, you can also use the PAM to improve the paper tear resistance and porous, to improve vision and printing performance, also used in food and tea packagingpaper.5.In other industries, the food industry, for cane sugar, beet sugar production in sugarcane juice clarificationandsyrupphosphorous floatationextraction.Enzyme fermentation liquid clarification industry, also for the recovery of protein feed, stable quality, good performance, recovery of protein powder on improving the survival rate of chicken and egg weight, no adverse effects, synthetic resin coating, of grouting material for water plugging, building materials industry, improve the quality of cement, construction adhesives, caulking repair and water plugging agent, soil improvement, electroplating industry, printing and dyeing industry.
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14 Items To Consider When Using Accelerators

The vulcanization accelerator is simply referred to as a promoter. The addition of a small amount of accelerator in the rubber compound can greatly promote the reaction between the rubber and the vulcanizing agent (crosslinking agent), and can accelerate the vulcanization reaction rate, shorten the vulcanization time, lower the vulcanization reaction temperature, and reduce the vulcanization agent dosage capacity. A compounding agent that enhances or improves the physical and mechanical properties of vulcanizates, and is called a vulcanization accelerator.The four major functions of the accelerator: First, shorten the vulcanization time, reduce the amount of sulfur, reduce the vulcanization temperature, and secondly improve the scorch performance of the rubber; third, improve the flatness of the rubber vulcanization and improve the performance of the rubber product; The appearance quality of the product.In the process of selecting and using the accelerator, according to the experience of some friends, we have compiled 14 items to consider when selecting the accelerator. Now we share with you:1. Rubber typeDifferent rubbers have different performance characteristics, different vulcanization systems, and different vulcanization systems should consider the matching between different types of accelerators.2. Promoter qualityQuality is one of the key considerations for formulators when using accelerators. In the current market, there are still many phenomena of counterfeiting and sub-priming, so it must be cautious when selecting, otherwise it will directly affect the performance of rubber vulcanization or anti-aging.3. Effect on the properties of rubber compounds and vulcanizatesThe accelerator participates in the formation of the rubber space network during vulcanization, and has a direct relationship with the structure of the vulcanized rubber, that is, the physical and mechanical properties and the aging properties. The accelerator has a softening effect on the rubber compound, which increases the plasticity of the rubber compound and changes the processing property of the rubber compound.4. Charring performanceThe accelerator has a decisive influence on the scorch time of the compound (i.e., the time until the thermal vulcanization of the compound begins). Therefore, the accelerator selected should have a considerable scorch time, which is the operation safety of the rubber compound during mixing, calendering, extrusion or injection, the fluidity of the rubber in the initial vulcanization and the attachment to the fabric. Efforts have a major impact. In particular, in recent years, in order to improve production efficiency, processing conditions are becoming more and more strict, and the requirements for anti-scorch performance of rubber compounds are also increasing. However, the excessive scorch time will lead to an increase in the total vulcanization time, which is not only unfavorable for the improvement of labor efficiency, but also has an adverse effect on the deformation of the moldless vulcanized product during the vulcanization process.5. Vulcanization flatnessThe accelerator should have a broad vulcanization flatness curve during the optimum vulcanization. In other words, the properties of the vulcanizate should not show significant changes during this time, which is especially important for thick rubber products and solid products. Rubber is a poor conductor of heat. The surface and internal heat of the vulcanizate are inconsistent. The broad vulcanization flatness is a guarantee to avoid excessive sulfur and uniform vulcanization of various parts of the product.6. DispersibilityAccelerators with poor dispersibility in the rubber compound not only require a long mixing time, but also increase the power consumption of the equipment, and often cause uneven vulcanization of the product due to uneven mixing. For some hard-to-disperse accelerators, it can be used as a masterbatch.7. SprayingThe blooming of the rubber compound will cause poor bonding to the subsequent process and reduce the appearance quality of the final product, so it should be avoided. Promoter spray and accelerator are related to the compatibility of rubber. Generally, non-polar EPDM rubber is easy to spray, while polar nitrile rubber and neoprene are difficult to spray. Among the accelerators, in particular, the accelerators TMTD and ZDMC are inferior in compatibility with rubber, and there is a possibility of blooming. The compatibility of the large alkyl promoter ZDEC and ZDBC with rubber is better than that of TMTD and ZDMC, and the blooming phenomenon is reduced.8. Pollution and colorationSome accelerators color the rubber products because they have different colors, and some of them are chemically or sun-exposed to make the products discolored. These accelerators cannot use white or brilliant products. Some accelerators have obvious odor and bitterness, and some accelerators can also contaminate other substances by contact migration.9. Environmental protectionMost of the accelerators currently used are not toxic or very toxic, but they are still toxic. These accelerators should not be used in medical products and food-contact rubber products. Use toxic or toxic accelerators to protect them during handling.The development trend of accelerators tends to be environmentally friendly and functional. In recent years, the international promotion of harmful nitrosamine promoters in the rubber processing process has been paid more and more attention. The environmentally-friendly new accelerators have been developed in developed countries such as Europe and the United States, and China has gradually paid more attention to environmental protection promotion in recent years. The development and production of agents and predispersions, among which environmentally friendly accelerators are represented by: ZBEC, TBzTD, TIBTD, ZBPD, ZDTP, NS, TBSI, MTT, etc.10. Water solubilityFor the production of latex products, it is convenient to use water-soluble accelerators, among which the representative products are: ZDEC, ZDBC, ZMBT, TMTD, MBT, etc.11. Promoter combinationEach kind of accelerator has its own characteristics. In order to satisfy the good process performance of the rubber during the operation and the excellent physical and chemical properties of the vulcanized rubber, several kinds can be used together and complement each other.Rubber properties are distinguished by the nature of the accelerator - the accelerator is divided into a primary accelerator and a secondary accelerator. The main accelerator, also known as the first accelerator, generally uses an acid promoter (referred to as type A) or a neutral accelerator (called type N). The most frequent thiazoles and thiurams, the scorch time sequence of thiazoles is: M < DM < MZ < sulfenamides. The thiuram primary accelerator is only used for film products or model products with extremely short curing time. Dithiocarbamate main accelerator, commonly used in latex products, as well as low-unsaturated rubber such as ethylene propylene rubber and butyl rubber.The secondary accelerator, also known as the second accelerator or the third accelerator, generally employs a basic accelerator (referred to as type B), and uses a hydrazine (such as a promoter DPG, DOTG, etc.). The accelerator H is also used, and the scorch time can be prolonged, and the amount of the secondary accelerator varies depending on the type of the main accelerator. The sulfenamide accelerator itself is a combination accelerator, and at the vulcanization temperature, the promoter M and the amine compound are decomposed to form an AB combined system. Therefore, a secondary accelerator may generally not be used. Of course, depending on the process requirements, a small amount of accelerator DPG or thiuram accelerator may be used in combination.12. CooperateWhen using the accelerator, factors such as interaction with other rubber additives and rubber raw materials should be considered.13. EconomicsThe selection of accelerators should take into account the ease of procurement of the product in the market. Unusual accelerators or difficult to purchase should pay attention to the impact on production when used in large quantities.The accelerators commonly found in the market must also take into account the purchase price problem. The use cost of the accelerator is one of the key issues for the formulator.14. ConfidentialityCommon rubber products find a recipe easy, but for special or technical rubber products, formula design requires a lot of energy and financial resources. Designing a rubber formula and keeping it secret is very important for the development of the company. The confidentiality of the formula must involve the confidentiality of the accelerator product, which is one of the important issues considered by the formulator and even the person in charge of the company.
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Comprehensive Analysis Of Pharmaceutical Wastewater Technology

Pharmaceutical industry wastewater mainly includes antibiotic production wastewater and synthetic drug production. Pharmaceutical industry wastewater mainly includes four categories: antibiotic production wastewater, synthetic drug production wastewater, Chinese patent medicine production wastewater, and washing water and washing wastewater in various preparation processes. The wastewater is characterized by complex composition, high organic content, high toxicity, deep chroma and high salt content, especially poor biochemical properties, and intermittent discharge, which is an industrial wastewater that is difficult to treat. With the development of China's pharmaceutical industry, pharmaceutical wastewater has gradually become one of the important sources of pollution. How to treat this type of wastewater is a difficult problem in environmental protection today.1. Treatment method of pharmaceutical wastewaterThe treatment methods of pharmaceutical wastewater can be summarized as follows: physical and chemical treatment, chemical treatment, biochemical treatment and combination treatment of various methods, and various treatment methods have their own advantages and disadvantages.1.1 Materialized treatmentAccording to the water quality characteristics of pharmaceutical wastewater, physicochemical treatment is required as a pretreatment or post-treatment process for biochemical treatment. The currently applied physical and chemical treatment methods mainly include coagulation, air flotation, adsorption, ammonia stripping, electrolysis, ion exchange and membrane separation.1.1.1 Coagulation methodThis technology is a water treatment method commonly used at home and abroad. It is widely used in the pretreatment and post-treatment of pharmaceutical wastewater, such as aluminum sulfate and polyferric sulfate for traditional Chinese medicine wastewater. The key to efficient coagulation treatment is to properly select and add coagulants with excellent performance. In recent years, the development direction of coagulants has evolved from low molecular to polymeric polymers, from single-component to complex-type functional [3]. Liu Minghua et al [4] treated a high-efficiency composite flocculant F-1 with a high-efficiency composite flocculant F-1 to treat COD, SS and chromaticity of waste liquor at pH 6.5 and flocculant dosage of 300 mg/L. The removal rates are 69.7%, 96.4% and 87.5%, respectively, and their performance is significantly better than PAC (powdered activated carbon), polyacrylamide (PAM) and other single flocculants.1.1.2 Air floatation methodThe air floatation method generally includes various forms such as aeration air floatation, dissolved air flotation, chemical air floatation, and electrolysis air floatation. Xinchang Pharmaceutical Factory uses CAF vortex air flotation device to pretreat pharmaceutical wastewater. With the appropriate agent, the average removal rate of COD is about 25%.1.1.3 Adsorption methodCommonly used adsorbents include activated carbon, activated coal, humic acids, and adsorption resins. Wuhan Jianmin Pharmaceutical Factory uses coal ash adsorption-two-stage aerobic biological treatment process to treat its wastewater. The results show that the adsorption pretreatment has a COD removal rate of 41.1% and an increase in BOD5/COD.1.1.4 Membrane separation methodMembrane technology includes reverse osmosis, nanofiltration membranes and fiber membranes to recover useful materials and reduce total emissions of organic matter. The main features of this technology are simple equipment, easy operation, no phase change and chemical change, high processing efficiency and energy saving. Juanna and others used a nanofiltration membrane to separate the cinnamycin wastewater. It was found that both the inhibitory effect of lincomycin on the microorganisms in the wastewater was reduced, and the cinnamycin was recovered.1.1.5 ElectrolysisThe method has the advantages of high efficiency, easy operation and the like, and the electrolysis method has a good decolorization effect. Li Ying [8] pretreated the riboflavin supernatant by electrolysis, and the removal rates of COD, SS and chromaticity reached 71%, 83% and 67%, respectively.1.2 Chemical treatmentWhen chemical methods are applied, the excessive use of certain reagents may easily lead to secondary pollution of water bodies. Therefore, relevant experimental research work should be done before design. Chemical methods include iron-carbon method, chemical redox method (fenton reagent, H2O2, O3), deep oxidation technology, and the like.1.2.1 Iron and carbon methodIndustrial operation shows that the biodegradability of effluent can be greatly improved by using Fe-C as a pretreatment step of pharmaceutical wastewater. Lou Maoxing used iron-micro-electrolysis-anaerobic-aerobic-air-floating combined treatment to treat wastewater from pharmaceutical intermediates such as erythromycin and ciprofloxacin. The COD removal rate after treatment with iron and carbon was 20%. %, the final effluent meets the national first-class standard of Integrated Wastewater Discharge Standard (GB8978-1996).1.2.2 Fenton reagent treatmentThe combination of ferrous salt and H2O2 is called Fenton's reagent, which can effectively remove the refractory organic matter that cannot be removed by traditional wastewater treatment technology. With the deepening of the research, ultraviolet light (UV), oxalate (C2O42-) and the like are introduced into the Fenton reagent, so that the oxidation capacity is greatly enhanced. Using TiO2 as catalyst and 9 W low-pressure mercury lamp as the light source, the pharmaceutical wastewater was treated with Fenton reagent, and the decolorization rate was 100%, the COD removal rate was 92.3%, and the nitrobenzene compound decreased from 8.05 mg/L. 0.41 mg/L.1.2.3 Oxidation methodThe method can improve the biodegradability of wastewater and has a good removal rate for COD. For example, Balcioglu and other three antibiotic wastewaters were subjected to ozone oxidation treatment. The results showed that the ozone oxidation wastewater not only increased the ratio of BOD5/COD, but also the COD removal rate was above 75%.1.2.4 Oxidation technologyAlso known as advanced oxidation technology, it brings together the latest research results of modern optical, electrical, acoustic, magnetic, materials and other similar disciplines, including electrochemical oxidation, wet oxidation, supercritical water oxidation, photocatalytic oxidation and Ultrasonic degradation method, etc. Among them, the ultraviolet photocatalytic oxidation technology has the advantages of novelity, high efficiency, no selectivity to wastewater, especially suitable for the degradation of unsaturated hydrocarbons, and the reaction conditions are mild, no secondary pollution, and has a good application prospect. Compared with ultraviolet, heat, pressure and other treatment methods, ultrasonic treatment of organic matter is more direct, and the requirements for equipment are lower. As a new type of treatment method, more and more attention is being paid. Xiao Guangquan et al [13] treated the pharmaceutical wastewater with ultrasonic-aerobic biological contact method. Under ultrasonic treatment for 60 s and power of 200 w, the total COD removal rate of wastewater was 96%.1.3 Biochemical treatmentBiochemical treatment technology is a widely used treatment technology for pharmaceutical wastewater, including aerobic biological method, anaerobic biological method, aerobic-anaerobic combination method.1.3.1 Aerobic biological treatmentSince most of the pharmaceutical wastewater is high-concentration organic wastewater, it is generally necessary to dilute the stock solution when performing aerobic biological treatment. Therefore, the power consumption is large, and the wastewater is biodegradable, and it is difficult to directly discharge the standard after biochemical treatment. Therefore, aerobic use alone. There are not many treatments, and general pretreatment is required. Commonly used aerobic biological treatment methods include activated sludge method, deep well aeration method, adsorption biodegradation method (AB method), contact oxidation method, sequencing batch intermittent activated sludge method (SBR method), and circulating activated sludge method. (CASS law) and so on.(1) Deep well aeration methodDeep well aeration is a high-speed activated sludge system. The method has the advantages of high oxygen utilization rate, small floor space, good treatment effect, low investment, low operating cost, no sludge expansion, and low mud production. In addition, its heat preservation effect is good, and the treatment is not affected by climatic conditions, which can ensure the effect of winter wastewater treatment in the northern region. After the high-concentration organic wastewater from the Northeast Pharmaceutical Plant was biochemically treated in the deep well aeration tank, the COD removal rate reached 92.7%. It can be seen that the treatment efficiency is very high, and it is extremely beneficial to the next step of treatment. Play a decisive role.(2) AB methodThe AB method is an ultra-high load activated sludge process. The removal rate of BOD5, COD, SS, phosphorus and ammonia nitrogen by AB process is generally higher than that of conventional activated sludge process. Its outstanding advantages are high load in section A, strong impact load resistance, and large buffering effect on pH and toxic substances. It is especially suitable for treating sewage with high concentration and large changes in water quality and quantity. Yang Junshi and other methods use the hydrolysis acidification-AB biological process to treat antibiotic wastewater, the process is short, energy saving, and the treatment cost is lower than the chemical flocculation-biological treatment method of the same kind of wastewater.(3) Biological contact oxidation methodThe technology integrates the advantages of activated sludge and biofilm method, and has the advantages of high volumetric load, low sludge production, strong impact resistance, stable process operation and convenient management. Many projects use a two-stage method, which aims to acclimate the dominant strains at different stages, give full play to the synergy between different microbial populations, and improve biochemical effects and impact resistance. In the engineering, anaerobic digestion and acidification are often used as pretreatment steps, and the contact oxidation process is used to treat pharmaceutical wastewater. Harbin North Pharmaceutical Factory used hydrolysis acidification-two-stage biological contact oxidation process to treat pharmaceutical wastewater. The operation results show that the treatment effect is stable and the process combination is reasonable. With the gradual maturity of the process technology, the application field is also more extensive.(4) SBR methodThe SBR method has the advantages of strong impact load resistance, high sludge activity, simple structure, no need for reflow, flexible operation, small land occupation, low investment, stable operation, high matrix removal rate, good nitrogen and phosphorus removal effect, etc. Fluctuating wastewater. The experiment of treating pharmaceutical wastewater with SBR process shows that the aeration time has a great influence on the treatment effect of the process; setting the anoxic section, especially the repeated design of anoxic and aerobic, can significantly improve the treatment effect; The SBR strengthening treatment process with PAC can significantly improve the removal effect of the system. In recent years, the process has become more and more perfect, and it has been widely used in the treatment of pharmaceutical wastewater. The bio-pharmaceutical wastewater has been treated by hydrolysis acidification-SBR method, and the effluent quality has reached the first-class standard of GB8978-1996.1.3.2 Anaerobic biological treatmentAt present, the treatment of high-concentration organic wastewater at home and abroad is mainly based on anaerobic method, but the effluent COD is still high after treatment by a separate anaerobic method, and generally requires post-treatment (such as aerobic biological treatment). At present, it is still necessary to strengthen the development and design of high-efficiency anaerobic reactors and conduct in-depth study of operating conditions. The most successful applications in the treatment of pharmaceutical wastewater are upflow anaerobic sludge blanket (UASB), anaerobic composite bed (UBF), anaerobic baffled reactor (ABR), hydrolysis, and the like.(1) UASB methodThe UASB reactor has the advantages of high anaerobic digestion efficiency, simple structure, short hydraulic retention time, and no need for a separate sludge reflux device. When UASB is used to treat pharmaceutical production wastewater such as kanamycin, chlorin, VC, SD and glucose, the SS content is usually not too high to ensure COD removal rate is above 85% to 90%. The COD removal rate of the two-stage series UASB can reach more than 90%.(2) UBF methodBuying Wenning et al. conducted a comparative test of UASB and UBF. The results show that UBF has the characteristics of good mass transfer and separation effect, large biomass and biological species, high processing efficiency and strong operational stability. Oxygen bioreactor.(3) Hydrolysis acidificationThe hydrolysis tank is referred to as a hydrolyzed upflow sludge bed (HUSB), which is an improved UASB. Compared with the whole process anaerobic tank, the hydrolysis tank has the following advantages: no need for sealing, stirring, no three-phase separator, which reduces the cost and facilitates maintenance; it can degrade large molecules and non-biodegradable organic substances in sewage into small molecules. Organic matter that is easily biodegradable, improves the biodegradability of raw water; rapid reaction, small tank volume, less capital investment, and reduced sludge volume. In recent years, the hydrolysis-aerobic process has been widely used in the treatment of pharmaceutical wastewater. For example, a biopharmaceutical plant uses a hydrolysis acidification-two-stage biological contact oxidation process to treat pharmaceutical wastewater. The operation is stable and the organic matter removal effect is remarkable. COD, BOD5 The removal rates of SS and SS were 90.7%, 92.4%, and 87.6%, respectively.1.3.3 Anaerobic-aerobic and other combined treatment processesBecause aerobic treatment or anaerobic treatment alone can not meet the requirements, anaerobic-aerobic, hydrolysis acidification-aerobic and other combined processes improve the biodegradability, impact resistance, investment cost and treatment effect of wastewater. Out of the performance of a single processing method, it has been widely used in engineering practice. For example, a pharmaceutical factory uses anaerobic-aerobic process to treat pharmaceutical wastewater, BOD5 removal rate is 98%, COD removal rate is 95%, and the treatment effect is stable. Micro-electrolysis-anaerobic hydrolysis acidification-SBR process is used to treat chemical synthesis of pharmaceutical wastewater. The results show that the whole series process has strong impact resistance to the change of wastewater quality and water volume, and the COD removal rate can reach 86%~92%, which is an ideal process choice for treating pharmaceutical wastewater; In the treatment of wastewater, the hydrolytic acidification-A/O-catalytic oxidation-contact oxidation process is adopted. When the influent COD is about 12 000 mg/L, the effluent COD is less than 300 mg/L; the biofilm-SBR method is used to treat the biological The removal rate of COD in pharmaceutical wastewater with refractory can reach 87.5%~98.31%, which is much higher than the treatment effect of biofilm method and SBR method alone.In addition, with the continuous development of membrane technology, the application research of membrane bioreactor (MBR) in pharmaceutical wastewater treatment has gradually deepened. MBR combines the characteristics of membrane separation technology and biological treatment, and has the advantages of high volumetric load, strong impact resistance, small floor space and less residual sludge. The anaerobic-membrane bioreactor process was used to treat the pharmaceutical intermediate acid chloride wastewater with COD of 25 000 mg/L. The COD removal rate of the system was maintained above 90%. The ability to degrade specific organic matter by obligate bacteria was adopted for the first time. The extraction membrane bioreactor was used to treat industrial wastewater containing 3,4-dichloroaniline. The HRT was 2 h, and the removal rate reached 99%, and the ideal treatment effect was obtained. Despite the problems in membrane fouling, with the continuous development of membrane technology, MBR will be more widely used in the field of pharmaceutical wastewater treatment.2. Treatment process and selection of pharmaceutical wastewaterThe water quality characteristics of pharmaceutical wastewater make it impossible for most pharmaceutical wastewater to be treated by biochemical treatment alone, so necessary pretreatment must be carried out before biochemical treatment. Generally, a regulating tank should be set to adjust the water quality and pH, and according to the actual situation, a physicochemical or chemical method is used as a pretreatment process to reduce the SS, salinity and partial COD in the water, and reduce the biological inhibitory substances in the wastewater, and Improve the degradability of wastewater to facilitate subsequent biochemical treatment of wastewater.The pretreated wastewater can be treated according to its water quality characteristics by an anaerobic and aerobic process. If the effluent requirements are high, the aerobic treatment process should be continued after the aerobic treatment process. The choice of specific process should take into account the nature of the wastewater, the treatment effect of the process, infrastructure investment and operation and maintenance, etc., so that the technology is feasible and economical. The overall process route is a pretreatment-anaerobic-aerobic- (post-treatment) combination process. The comprehensive pharmaceutical wastewater containing artificial insulin and the like is treated by a hydrolysis adsorption-contact oxidation-filtration combination process, and the treated effluent water quality is superior to the first-class standard of GB8978-1996. Air flotation-hydrolysis-contact oxidation process for chemical pharmaceutical wastewater, composite micro-oxygen hydrolysis-composite aerobic-sand filtration process for antibiotic wastewater, air flotation-UBF-CASS process for treatment of high-concentration Chinese medicine extraction wastewater, etc. effect.3. Recycling of useful materials in pharmaceutical wastewaterPromote clean production in the pharmaceutical industry, improve the utilization rate of raw materials, and the comprehensive recovery rate of intermediate products and by-products, and reduce or eliminate pollution in the production process through reforming processes. Due to the particularity of certain pharmaceutical production processes, the wastewater contains a large amount of recyclable materials. For the treatment of such pharmaceutical wastewater, material recovery and comprehensive utilization should be strengthened first. For the ammonium salt content of the pharmaceutical intermediate wastewater up to 5% to 10%, the fixed scraper film is used for evaporation, concentration, crystallization, and the recovery of (NH4)2SO4 and NH4NO3 with a mass fraction of about 30% is used as a fertilizer or reuse. Obvious economic benefits; a high-tech pharmaceutical company uses blow-off method to treat production wastewater with extremely high formaldehyde content. After recovery, formaldehyde gas can be formulated into formalin reagent or burned as boiler heat source. Through the recovery of formaldehyde, the resources can be used sustainably, and the investment cost of the treatment station can be recovered within 4 to 5 years, achieving the unification of environmental and economic benefits. However, in general, pharmaceutical wastewater has complex composition and is difficult to recycle, and the recycling process is complicated and the cost is high. Therefore, advanced and efficient integrated wastewater treatment technology is the key to completely solve the sewage problem.4. the conclusionThere have been many reports on the treatment of pharmaceutical wastewater. However, due to the diversity of raw materials and processes in the pharmaceutical industry, the wastewater quality of wastewater is very different. Therefore, pharmaceutical wastewater does not have a mature and unified treatment method. Which process route is selected depends on the wastewater. nature. According to the characteristics of the wastewater, it is generally necessary to pre-treat to improve the biodegradability of the wastewater and to initially remove the pollutants, and then combine biochemical treatment. At present, the development of an economical and effective composite water treatment unit is an urgent problem to be solved. At the same time, research on cleaner production should be strengthened, and the value of waste water recycling and appropriate ways should be considered in the early stage of treatment to achieve the unification of economic and environmental benefits.
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