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659results about How to "Reduce COD value" patented technology

Treatment method for realizing zero emission of printing and dyeing wastewater

The invention discloses a treatment method for realizing zero emission of printing and dyeing wastewater. The treatment method comprises the following steps: performing physicochemical and biochemical treatments on printing and dyeing wastewater stoste; performing such advanced treatments on the discharged water as sand filtration, ultrafiltration and security filtration, and then, conveying the discharged water into a nanofiltration or reverse osmosis membrane treatment system to perform membrane treatment, thus obtaining fresh water and concentrated water through the membrane treatment, wherein the fresh water is low-COD and low-hardness ionized water and is used as process water to be directly recycled in dyeing procedure, boiler water addition, general washing or circulating cooling water. The concentrated water is high-salinity and high-hardness wastewater containing organic pollutants, the concentrated water is treated by a Fenton oxidation coupling lime soda method, the concentrated water becomes low-COD and low-hardness water with high salinity, and salt is directly added in the concentrated water according to dyeing process requirements so as to recycle the concentrated water in the dyeing procedure. The treatment method provided by the invention can be used for completely recycling the treated wastewater to realize zero emission of printing and dyeing enterprises and save the cost, and the treatment method is free of secondary pollution, thereby protecting the ecological environment and recycling the printing and dyeing wastewater.
Owner:SOUTH CHINA UNIV OF TECH

Cooperative pretreatment method for biological catalysis and controlled oxidation of cotton and cotton-type fabrics

The invention relates to a cooperative pretreatment method for biological catalysis and controlled oxidation of cotton and cotton-type fabrics, comprising the following steps: (1) preparing a biological compound enzyme preparation, a biological enzyme synergist and a non-ionic surfactant into an enzyme working solution, wherein the pH of a processing bath is 6-7.5; padding the fabrics into the working solution; carrying out heat preservation; (2) washing the processed fabrics with cold water; padding the fabrics into a hydrogen peroxide bleaching solution containing the controlled decomposition additive of hydrogen peroxide; and steaming, washing with water and drying to obtain the finished products. In the method, high-density strong base is not required to serve as a scouring agent, thepH value of pretreatment waste water is 7-8, the chromaticity is low, the COD (Chemical Oxygen Demand) value is lowered by 30% compared with that of the traditional alkali kiering pretreatment technology, the water is saved by 10-30%, and the steam and electricity can be saved by 20%. The indexes (whiteness, capillary effect, water absorption, cotton seed hull strainaway rate, desizing rate, strong force and the like) of the processed cotton and cotton-type fabric all reach the quality indexes of a semi-product, cotton seed hulls can be completely removed, and the fabrics have vivid color andgood levelling property after being dyed.
Owner:DONGHUA UNIV

Chemical bond connected strong cationic grafted amphoteric chitosan flocculant and preparation method thereof

The invention relates to a chemical bond connected strong cationic grafted amphoteric chitosan flocculant which is obtained by grafting strong cationic monomers to amphoteric carboxymethyl chitosan in an acidic condition through copolymerization. The chemical bond connected strong cationic grafted amphoteric chitosan flocculant is in such a structure as follows: in the chemical bond connected strong cationic grafted amphoteric chitosan flocculant, degree of substitution of a carboxylic acid group is 5-90%, methylacryloyl oxyethyl trimethyl ammonium chloride is a strong cationic monomer, and polymethylacryloyl oxyethyl trimethyl ammonium chloride accounts for 5-80% by mass of the chemical bond connected strong cationic grafted amphoteric chitosan flocculant. The flocculant provided by the invention has amphoteric characteristics, so that not only is the flocculant property improved, but also the dissolving property is improved. The raw material chitosan is wide in source, natural, non-toxic and degradable. The flocculant has multiple functions of good flocculation effect, metal ion absorption, bacteriostasis, deodorization, decoloration, and effective reduction of COD (Chemical Oxygen Demand) value and the like.
Owner:NANJING UNIV

Preparation method of grafted amphoteric starch flocculants

The invention discloses a preparation method of grafted amphoteric starch flocculants, which is implemented by carrying out graft copolymerization on cationic starches, acrylamide and an acrylic acid so as to obtain a grafted amphoteric starch flocculant, and the grafted amphoteric starch flocculant has the following structure shown in the abstract. The method disclosed by the invention has the following advantages that because a molecular chain is rich in anion-cation groups and has amphoteric characteristics, not only is the flocculation property of materials improved, and also the dissolving property of starches is improved; high polymer materials are wide in resource and low in cost, so that the grafted amphoteric starch flocculant has a high performance price ratio; starches have biodegradability and are non-toxic, so that starches do not produce secondary pollution to water bodies; the grafted amphoteric starch flocculant has various good effects such as flocculation, metal ion adsorption, bacteriostasis, deodorization, decoloring, and capability of effectively reducing the COD value; the grafted amphoteric starch flocculant has a characteristic of high efficiency, and is low in putting amount, and the putting amount is generally 0.1-10mg / L; and the the grafted amphoteric starch flocculant is suitable for treating water bodies with different charges, good in salt resistance and wide in applied pH range, and can be applied when the pH value is 1-12.
Owner:NANJING UNIV

Method for recycling ethylene glycol and acetaldehyde from polyester waste water

The invention discloses a method for recycling ethylene glycol and acetaldehyde from polyester waste water. The method is implemented by the following steps of: (1) introducing esterification waste water into a stripping tower for treating and directly introducing organic matter gas and water vapor collected from a tower top into an acetaldehyde rectifying tower; (2) treating in the acetaldehyde rectifying tower, collecting high-purity acetaldehyde from the tower top and introducing waste water collected from a tower bottom into an ethylene glycol distillation tower; and (3) treating in the ethylene glycol distillation tower, collecting a high-purity ethylene glycol solution from the tower bottom and introducing waste gas and water vapor produced on the tower top into the stripping tower for cyclic treatment. In the method, acetaldehyde and ethylene glycol are continuously collected, so that hydrolysis of byproduct of 2-methyl-1,3-dioxolane in the esterification waste water is continuously performed positively and negatively, acetaldehyde with the concentration of over 95 percent and ethylene glycol with the concentration of over 70 percent are obtained at the end of treatment, and the 2-methyl-1,3-dioxolane is fully hydrolyzed.
Owner:SHANGHAI JUYOU CHEM ENG +1

Low-alkali pretreatment method for in-situ catalytic degradation of impurities in cotton and cotton fabrics

The invention relates to a low-alkali pretreatment method for the in-situ catalytic degradation of impurities in cotton and cotton fabrics, which comprises the following steps: (1) preparing a biological compound enzyme preparation, a biological enzyme synergist and a nonionic surfactant into enzyme working fluid; padding a fabric in the enzyme working fluid; and carrying out heat preservation on the fabric; and (2) directly padding the treated fabric into hydrogen peroxide bleaching liquid containing a hydrogen peroxide controlled decomposing additive, and then steaming, washing and drying the fabric. According to the invention, sizes and impurities are subjected to in-situ catalytic degradation in fabrication processing, therefore, an effect of ultrahigh-concentration wastewater treatment is achieved, fabrics are easy to wash, the washing temperature and washing frequency are reduced, more than 25% of water is saved, more than 30% of steam is saved, and more than 10% of electricity is saved. The COD (chemical oxygen demand) value is reduced by more than 30% in comparison with that of a traditional alkali scouring process, the B / C value of pretreated wastewater is about 0.4, and the biodegradability is improved. All indexes (such as whiteness, capillary effect, cottonseed hull removal rate, desizing ratio, strength, and the like) of treated cotton and cotton fabrics meets the quality requirements of semi-finished products.
Owner:DONGHUA UNIV

Hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent and preparation method thereof

The invention discloses a hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent. The hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent is characterized by being obtained by carrying out hydrolysis reaction onto graft carboxymethyl cellulose under alkali condition, wherein the hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent has the structure shown in the specification; the mass of polyacrylamide is 5%-65% of that of the hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent; and the mass of the polyacrylic acid is 5%-70% of the that of the hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent. The hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent disclosed by the invention has the triple characteristic of carboxymethyl anionic group, polyacrylamide and polyacrylic acid. Moreover, the carboxymethyl anionic group, polyacrylamide and polyacrylic acid are linked by chemical bonds, so that the molecular weight of carboxymethyl cellulose is improved and the bonding and bridging flocculation is enhanced. Besides, the soluble pH range of the hydrolysis graft strengthened anionic carboxymethyl cellulose flocculating agent is expanded due to the existence of the grafting chain, and therefore, the pH sensitivity of the flocculation effect of carboxymethyl cellulose is effectively restrained.
Owner:NANJING UNIV

Reuse treatment method for industrial wastewater from refrigerator compressor factory

The invention relates to a reuse treatment method for industrial wastewater from a refrigerator compressor factory. Firstly, independently collected emulsified bath solution wastewater is acidified and demulsified, free oil and emulsified oil in the wastewater are eliminated, and then the wastewater is subjected to Fe<2+>/H2O2 oxidation, the effluent pH is 7-8, and then coagulant aid is added forcoagulation sedimentation, and organic matter, metal salt and SS are removed, so that emulsified bath solution water is obtained. Subsequently, the emulsified bath solution water and the independently collected rinsing wastewater are uniformly mixed according to the ratio of 1:20-30 to serve as the source water for micro filter membrane treatment; the source water is subjected to air floatation oil separation dephosphorization, coagulation and activated carbon adsorption to obtain water with the pH value of 9-10 under micro filtration, and then the water under micro filtration enters the micro filter membrane, so clean water is obtained; and the clean water and tap water are mixed according to the ratio of 1:1-2, are subjected to filtering by activated carbon and 5um precise filtration and enter a reverse osmosis membrane, and then pure water is obtained after desalination, and the pure water can be reused for production. With the reuse treatment method, the water quality of reused water is stable and can reach the standard of pure water used by enterprises for production, the water is reused for a product line, so that the wastewater discharge of the enterprises is greatly reduced, the use volume of tap water is saved, and remarkable economical and social benefits are achieved.
Owner:TONGJI UNIV +1

Advanced treatment process and apparatus for reverse osmosis concentrated water

The invention relates to a technology and a device for the advanced processing of reverse osmosis condensed water, wherein the technology is as follows: reverse osmosis condensed water which is directly outputted and discharged is inputted into a processor with inside-arranged biological active carbon, then ozone of the reverse osmosis condensed water, which has the density of 5 mg / L to 50 mg / l, is added on the aeration grid part of the processor; the ozone reacts with hydroxide free radicals to form oxyhydrogen free radicals of strong oxidbility in the processor; the hydroxide free radicals are used for oxidizing and decomposing organic polluting substances in the reverse osmosis condensed water, and the reverse osmosis condensed water processed by the ozone is directly outputted from the processor. The device comprises a base, a filtration cylinder and a reverse washer, wherein active carbon is put in the filtration cylinder. The hydroxide free radicals of strong oxidbility generated by the reaction of the ozone and the hydroxide free radicals are used as an oxidization middle product for oxidizing the organic polluting substances which can not be degraded in the reverse osmosis condensed water to form the organic substances which can be conveniently absorbed by the active carbon and biologically degraded, and COD value is lowered.
Owner:HUEYA ENVIRONMENTAL ENG

Method for treating naphthoquinone production liquid waste containing hexavalent chromium and vitamin K3 production wastewater and co-producing chromium oxide green

The invention relates to a method for treating naphthoquinone production liquid waste containing hexavalent chromium and vitamin K3 production wastewater and co-producing chromium oxide green. The method comprises the following steps: a) carrying out liquid phase reaction between the naphthoquinone production liquid waste and the vitamin K3 production wastewater at 80-260 DEG C, wherein the naphthoquinone production liquid waste is excessively used relative to a necessary dosage of complete reduction; b) adding a reducing agent into the obtained reaction mixture to reduce the residual hexavalent chromium; c) regulating the pH of the obtained reaction mixture to 5.5-8.5 to separate out chromium hydroxide, and separating to obtain the chromium hydroxide and filtrate; and d) transforming the chromium hydroxide obtained in the step c) into chromium oxide green. The method can be used for effectively treating the naphthoquinone production liquid waste and the vitamin K3 production wastewater generated in a vitamin K3 production chain and recycling effective components in the liquid waste to turn waste into wealth and improve the economic and environmental protection benefits at the same time.
Owner:绵阳市安剑皮革化工有限公司

Method for recovering organic matters in polyester wastewater

The present invention discloses a method for recovering organic matters in polyester wastewater. The method comprises the following steps that: (1) polyester wastewater enters a gas stripping tower to be subjected to a treatment, and organic matter gas and steam collected from the top of the tower directly enter an acetaldehyde rectification tower; (2) after treatment by the acetaldehyde rectification tower, high purity acetaldehyde is obtained from the top of the tower, and is divided into two parts, one part is externally collected, and the other part is reused for the gas stripping tower in the step (1), such that the acetaldehyde reacts with a small amount of ethylene glycol in the wastewater to produce 2-methyl-1,3-dioxolane, concurrently 2-methyl-1,3-dioxolane hydrolysis during the process is reduced, and the wastewater on the bottom of the tower enters an ethylene glycol distillation tower; and (3) after treatment by the ethylene glycol distillation tower, a high purity ethylene glycol solution is collected from the bottom of the tower, and waste gas and steam produced from the top of the tower re-enter the gas stripping tower to be recycled. According to the present invention, continuous acetaldehyde and ethylene glycol collection is adopted, such that gas stripping efficiency is increased so as to further reduce a COD value of the sewage on the bottom of the tower, wherein the sewage is subjected to the gas stripping treatment.
Owner:SHANGHAI JUYOU CHEM ENG +1

On-line cleaning agent for alkaline washing towers as well as preparation and use methods of cleaning agent

The invention relates to the technical field of ethylene and provides an on-line cleaning agent for alkaline washing towers as well as preparation and use methods of the cleaning agent. The cleaning agent is prepared from components in percentage by weight as follows: 20%-40% of a dispersing agent, 5%-10% of a stripping agent, 5%-10% of a penetrant, 25%-30% of an inhibitor and the balance of a solvent. The dispersing agent, the stripping agent, the penetrant, the inhibitor and the solvent are added to a reaction kettle in percentage by weight, stirred at the normal temperature and evenly mixed, and the cleaning agent is obtained through filtration. The cleaning agent is applied to the alkaline washing towers, stable production by devices can be guaranteed, further accumulation of scale in the alkaline washing towers is prevented, tower tray polymers are reduced, the blockage phenomenon of the alkaline washing towers can be eliminated by the aid of the cleaning agent for the alkaline washing towers, blockage of tower trays of new towers can be avoided, the butter amount and the COD value can be decreased, and accumulation of scale in old towers and the quantity of tower tray polymers can be reduced, so that real-time on-line cleaning of the alkaline washing towers can be realized.
Owner:天津市瑞德赛恩新材料开发有限公司
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