CN113045059A - Treatment system and treatment process for realizing zero discharge of wastewater by full-membrane method - Google Patents

Abstract

Translated fromChinese

本发明提出一种将全膜法做到废水零排放的处理系统及处理工艺，采用至少澄清池+过滤器的预处理工艺以及采用超滤+两级反渗透+电除盐的全膜法处理工艺，本系统内所有产生的浓水、反洗排水等废水均在系统内循环使用，不能直接循环使用的废水也经过处理达到软化水的水质标准后进入热网补充水系统，可实现做到系统内水全部使用，最终无任何废液排出工厂，水中的废物则以固体的形式外运回收，本发明的处理工艺的预处理工艺实用性强，适用的水质范围广，安全性高，符合当下对环保的要求。

The present invention proposes a treatment system and a treatment process for realizing zero discharge of waste water by an all-membrane method, which adopts at least a pretreatment process of a clarifier and a filter, and a full-membrane method of ultrafiltration, two-stage reverse osmosis, and electric desalination. Process, all the waste water such as concentrated water and backwashing drainage generated in this system are recycled in the system, and the waste water that cannot be directly recycled is also treated to reach the water quality standard of softened water and then enters the heating network supplementary water system, which can achieve All the water in the system is used, and finally no waste liquid is discharged from the factory, and the waste in the water is transported and recycled in the form of solids. Current requirements for environmental protection.

Description

Treatment system and treatment process for realizing zero discharge of wastewater by full-membrane method

Technical Field

The invention relates to the field of water treatment, in particular to the technical field of pretreatment and full-membrane treatment of incoming water and zero discharge of wastewater.

Background

The water source for water treatment usually adopts rivers, lakes, underground water, reclaimed water and the like, the water often contains a large amount of pollutants such as suspended matters, colloids, hardness, organic matters, dissolved substances and the like, and various impurities are removed by carrying out pretreatment and desalination treatment on the water to meet the water quality requirement of water. The main purpose of the pretreatment is to remove pollutants in the incoming water, including suspended matters, hardness, organic matters and the like, and carry out desalination treatment after meeting the water quality requirement of the incoming water of the subsequent desalination equipment. The most common process for pretreatment employs clarification and filtration. The desalting treatment is various, and the desalting process adopts a water treatment process by a whole membrane method.

The whole membrane method water treatment process is one of the current common water treatment methods, and with the scientific progress and the development of the water treatment technology, the whole membrane method water treatment process is mature and complete and the application range is wide. The whole membrane method water treatment process organically combines different membrane processes such as ultra/micro filtration, reverse osmosis, electric desalting and the like together to achieve the purposes of efficiently removing pollutants and deeply desalting, wherein the water quality of effluent water is less than 10 mug/L of silicon dioxide, and the conductivity (25 ℃) is less than 0.10 mug/cm. The high-quality effluent quality ensures that the water treated by the full-film method has wide application and can be used for boiler make-up water, process water, circulating water, heat supply network make-up water and the like. Can be used as electronic ultrapure water after further treatment. The whole membrane method has the advantages of simple operation and maintenance, modular design, convenient installation, continuous water discharge, no generation of acid-base wastewater, program control, high automation degree, stable water quality of discharged water and the like.

Waste water with different water volumes and water qualities can be generated in the pretreatment and membrane treatment processes at all levels, the waste water accounts for about 40-50% of the total water inflow, and if the waste water is directly discharged, a large amount of waste of water resources is caused, and adverse effects are generated on the environment. At present, according to the requirement of environmental protection, more and more power plants need to realize zero discharge of waste water. In order to improve the utilization rate of water, reduce wastewater discharge and achieve the aims of using water in steps and having multiple purposes, wastewater at all levels needs to be recycled.

The zero discharge of the wastewater refers to the process that the wastewater generated by industrial water treatment can be recycled step by step in the system without treatment, and the water which cannot be directly recycled in the system is recycled after treatment, so that the water in the system is completely used, no waste liquid is discharged out of a factory finally, and the waste in the water is recycled in a solid form.

Disclosure of Invention

The invention aims to solve the technical problem of providing a treatment system and a treatment process for realizing zero discharge of wastewater by a full-membrane method, and effective measures are taken according to the water quality characteristics of wastewater generated by treatment at all levels to realize gradual reuse of the wastewater and finally realize zero discharge of the wastewater.

The technical means adopted by the invention are as follows.

The invention discloses a treatment system for realizing zero discharge of wastewater by an all-membrane method, which comprises a pretreatment system and an all-membrane water treatment system: the pretreatment system comprises a regulating tank, a clarification tank and a filter which are connected in sequence, wherein the clarification tank is provided with an alkali dosing device, a coagulant dosing device and a coagulant aid dosing device, and an outlet pipeline of the clarification tank is provided with an acid dosing device; the whole-membrane water treatment system comprises an ultrafiltration system, a primary reverse osmosis system, a secondary reverse osmosis system and an electric desalting system which are connected in sequence, wherein an outlet of the filter is connected with an inlet of the ultrafiltration system, a reducing agent feeding device and a scale inhibitor feeding device are arranged in front of the inlet of the primary reverse osmosis system, a secondary reverse osmosis concentrated water outlet of the secondary reverse osmosis system and a concentrated water outlet of the electric desalting system are respectively connected in front of the reducing agent feeding device and the scale inhibitor feeding device in a returning manner, a primary reverse osmosis concentrated water outlet of the primary reverse osmosis concentrated water system is connected with a sodium ion softener, and a softened water outlet of the sodium ion softener is returned to a heat net for recycling; and the backwashing water outlet of the filter, the backwashing water outlet of the ultrafiltration system and the regeneration flushing water outlet of the sodium ion softener are all connected with the regulating tank in a return way.

Preferably, the clarification tank is the one-level clarification tank and the second grade clarification tank that arrange in order, the one-level clarification tank is equipped with first alkali charge device, and the second grade clarification tank is equipped with the second alkali charge device, and this one-level clarification tank, second grade clarification tank all are equipped with coagulant charge device and coagulant aid charge device, acid charge device is located the clear water outlet of second grade clarification tank, the equalizing basin is equipped with germicide and adds the feeder.

Preferably, be equipped with first middle water tank between one-level clarification tank and the second grade clarification tank, be equipped with the middle water tank of second between second grade clarification tank and the filter, acid charge device locates before the entry of this second middle water tank.

Preferably, a clear water tank is arranged between the ultrafiltration system and the primary reverse osmosis system, a secondary reverse osmosis concentrated water outlet of the secondary reverse osmosis system and a concentrated water outlet of the electric desalting device are both connected to the clear water tank in a return mode, and the reducing agent feeding device and the scale inhibitor feeding device are arranged behind the outlet of the clear water tank; be equipped with the one-level fresh water tank between one-level reverse osmosis system and the second reverse osmosis system, be equipped with the second grade fresh water tank between second grade reverse osmosis system and the electric desalination system, the demineralized water export of electric desalination system sets up the demineralized water tank.

Preferably, a reverse osmosis concentrated water tank is arranged between the primary reverse osmosis device and the sodium ion softener, a softened water outlet of the sodium ion softener is connected with the softened water tank, and an outlet of the softened water tank returns to the heat supply network for recycling.

Preferably, the first alkali dosing device is a lime or sodium hydroxide dosing device, and the second alkali dosing device is a sodium carbonate dosing device.

The invention also provides a treatment process for realizing zero discharge of wastewater by using the full-membrane method, which is applied to the treatment system and at least comprises the following steps:

step 1, incoming water enters a regulating tank and is uniformly mixed with other recovered water;

step 2, the mixed water obtained in the step 1 sequentially enters at least one stage of clarification tank, and coagulation, clarification and hardness removal treatment are carried out through the at least one stage of clarification tank;

step 3, sequentially filtering the clarified water obtained in thestep 2 through a filter and performing ultrafiltration through anultrafiltration system 21 to remove suspended matters and obtain clear water;

step 4, enabling the clean water obtained in the step 3 to sequentially enter a first-stage reverse osmosis system and a second-stage reverse osmosis system (23), and performing pre-desalination treatment through two-stage reverse osmosis to obtain fresh water;

step 5, desalting the fresh water obtained in the step 4 by an electric desalting system to finally prepare desalted water; in the step 3, backwashing drainage water generated by the filter and the ultrafiltration system is recycled to the regulating tank, and is uniformly mixed and then treated for reuse;

in the step 4, after the concentrated water generated by the primary reverse osmosis is subjected to sodium ion softening treatment, the obtained softened water is used for the supply water of the heat supply network, the regenerated flushing drainage generated by the sodium ion softening treatment is recycled to the regulating tank, the regenerated flushing drainage generated by the sodium ion softening treatment is uniformly mixed and then treated and reused, and the concentrated water generated by the secondary reverse osmosis and the concentrated water generated by the electric desalting treatment are recycled to the primary reverse osmosis system and participate in the pre-desalting treatment again.

Preferably, the mixed water in the step 1 is subjected to aeration and sterilization treatment in a regulating tank; in thestep 2, the mixed water sequentially passes through a primary clarification tank and a secondary clarification tank, lime or sodium hydroxide, a coagulant and a coagulant aid are added after the mixed water enters the primary clarification tank, sodium carbonate, the coagulant and the coagulant aid are added after the obtained clarified water enters the secondary clarification tank, the obtained clarified water is alkaline, acid is added after the clarified water is discharged to reduce the pH value, and the step 3 is carried out on the clarified water after the pH value is adjusted; in the step 3, clear water generated by the ultrafiltration system firstly enters the clear water tank, concentrated water generated by the secondary reverse osmosis system and concentrated water generated by the electric desalting system return to the clear water tank, reducing agents and scale inhibitors are sequentially added into an outlet pipeline of the clear water tank, and the mixture enters the primary reverse osmosis system after being mixed.

Preferably, the storage time of the adjusting tank is 1-2 hours, and the retention time of each clarification tank is about 1-1.5 hours.

Preferably, the adjusting tank and the at least one stage of clarification tank discharge sludge, and the sludge is made into a sludge cake after concentration and dehydration and is recovered as solid.

The invention has the following beneficial effects: according to the characteristics of the water quality of wastewater generated by each stage of treatment, firstly, the water source is recycled according to the quality, the recycled wastewater which is not treated by additional equipment is recycled to the corresponding position in the system, and the primary reverse osmosis concentrated water which cannot be recycled is further treated and then is reused.

1. Firstly, recovering waste water with high suspended matters such as filter backwashing water, ultrafiltration backwashing water and the like to an adjusting tank, uniformly mixing the waste water with incoming water, and then, treating the waste water in a clarification tank. And (4) returning the wastewater with low salt content of the secondary reverse osmosis concentrated water and the electric desalting concentrated water to a clear water tank, mixing the wastewater with the ultrafiltration effluent, and then performing primary reverse osmosis treatment. The first-stage reverse osmosis concentrated water is further subjected to sodium ion softening treatment and is used as available heat supply network supplementing water. Fully recovers available water sources and ladder water, changes waste into valuable and greatly improves the recovery rate of the system.

2. The treatment process provided by the invention gets rid of the defect that primary reverse osmosis concentrated water in a traditional full-membrane water treatment system has large water quantity but no place to use, provides a targeted treatment method for the primary reverse osmosis concentrated water, obtains desalted water and comprehensively utilizes the primary reverse osmosis concentrated water, namely the primary reverse osmosis concentrated water is treated by a softening method, removes most hardness in the concentrated water, meets the quality requirement of supply water of a heat supply network, obtains softened water reaching the quality of the supply water of the heat supply network, integrally realizes zero emission of water treatment, avoids the influence of discharge of the concentrated water into the environment on the aquatic ecological environment, and protects the environment.

3. The pretreatment process of the treatment process has strong practicability and wide applicable water quality range. The water treatment process adopting the whole membrane method has the advantages of modular externalization design, simple operation and maintenance, no generation of acid-base wastewater, program control, high automation degree, stable effluent quality and the like.

4. The traditional wet and cold gas turbine power plant is mostly built in cities, the requirement on drainage is higher, and the first-stage reverse osmosis concentrated water of the gas turbine power plant can only be discharged if the first-stage reverse osmosis concentrated water is not treated, so that the treatment system and the treatment process provide an effective method for the gas turbine power plant which needs zero emission.

6. Under the normal operating condition, all waste water that produce in the system all uses the processing in the system, and waste water is not arranged outward, and the security is high, accords with the requirement to the environmental protection at present.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Detailed Description

The invention adopts a pretreatment process of a clarification tank and a filter and a full-membrane treatment process of ultrafiltration, two-stage reverse osmosis and electric desalting. The embodiment shown in fig. 1 comprises a pretreatment system 1 and a full membrane processwater treatment system 2.

The pretreatment system 1 comprises a regulatingreservoir 11, aprimary clarifier 12, a firstintermediate water tank 31, a secondary clarifier 13, a secondintermediate water tank 32 and a filter 14 which are connected in sequence.

Theprimary clarifier 12 is provided with a first alkali dosing device which is a lime or sodium hydroxide dosing device. The second-stage clarification tank 13 is provided with a second alkali dosing device which is a sodium carbonate dosing device. In addition, a coagulant adding device and a coagulant aid adding device are arranged in theprimary clarification tank 12 and the secondary clarification tank 13. And an acid dosing device is arranged on a pipeline in front of the outlet of the secondary clarification tank 13 and the inlet of the secondintermediate water tank 32. In addition, a bactericide adding device is arranged in the adjustingtank 11.

Theadjusting tank 11, theprimary clarification tank 12 and the secondary clarification tank 13 are all provided with sludge discharge ports, 3 sludge discharge ports are communicated with an inlet of asludge concentration tank 71, and an outlet of thesludge concentration tank 71 is connected with a dehydrator 72 for concentrating and dehydrating sludge to form solid sludge cakes.

After a certain period of operation of the filter 14, which requires backwashing cleaning, the backwash drain is connected back to the regulatingreservoir 11.

The whole-membranewater treatment system 2 comprises anultrafiltration system 21, a clean water tank 4, a primaryreverse osmosis system 22, a primaryfresh water tank 51, a secondaryreverse osmosis system 23, a secondaryfresh water tank 52, anelectric desalting system 24 and a desalting water tank 53 which are connected in sequence. The outlet of the filter 14 is connected to the inlet of theultrafiltration system 21.

A reducing agent feeding device and a scale inhibitor feeding device are arranged on a pipeline between the outlet of the clean water tank 4 and the inlet of the primaryreverse osmosis system 22.

The first-stage reverse osmosis concentrated water outlet of the first-stage reverse osmosis concentratedwater system 22 is connected with a reverse osmosis concentratedwater tank 61, asodium ion softener 25 and asoftening water tank 62 in sequence.

The second-stage reverse osmosis concentrated water outlet of the second-stagereverse osmosis system 23 and the desalting concentrated water outlet of thedesalting system 24 are both connected with the clear water tank 4 in a return mode.

After theultrafiltration system 21 is operated for a period of time, backwashing cleaning is required, thesodium ion softener 25 also needs regeneration washing cleaning, and a backwashing water outlet of theultrafiltration system 21 and a regeneration washing water outlet of thesodium ion softener 25 are both connected back to the regulatingtank 11.

And a lifting water pump is arranged at a proper position in front of the clarification tank, the reverse osmosis system, the sodium ion softener and the desalting system so as to provide water source power for the subsequent process.

The apparatuses such as the clarification tank, the filter, the ultrafiltration system, the reverse osmosis system, the desalination system, the softener and the like can be one or more.

The water treatment process using the system mainly comprises pretreatment and full-membrane desalination, and wastewater mainly generated in the treatment process comprises backwashing drainage of the filter 14, backwashing drainage of theultrafiltration system 21, concentrated water of the primaryreverse osmosis system 22, concentrated water of the secondaryreverse osmosis system 23, concentrated water of theelectric desalination system 24 and regenerated wastewater of thesodium ion softener 25. The treatment process of the present invention is based on the above characteristics of wastewater and uses the illustrated treatment system, since hardness is the main cause of equipment fouling, and hardness includes temporary hardness and permanent hardness. Therefore, the hardness of the incoming water needs to be removed, as follows.

Step 1, the incoming water enters a regulatingtank 11 and is uniformly mixed with other recovered water. And is treated by aeration and bactericide during the mixing process in the adjustingtank 11.

And 2, the mixed water obtained in the step 1 sequentially enters aprimary clarification tank 12 and a secondary clarification tank 13, and theprimary clarification tank 12 and the secondary clarification tank 13 are used for adding alkali, coagulating and clarifying, so that the temporary hardness, alkalinity and suspended matters of the incoming water are reduced. Specifically, after the mixed water enters theprimary clarifier 12, lime or sodium hydroxide is added, then coagulant is added, and finally coagulant aid is added, and the obtained clarified water enters the firstintermediate water tank 31 for temporary storage. After the clear water in the firstintermediate water tank 31 is pumped into the secondary clarification tank 13, sodium carbonate is added firstly, then coagulant is added, finally coagulant aid is added to reduce the permanent hardness and suspended matters of the incoming water, the obtained clear water is alkaline, acid is added to reduce the pH value after the clear water is discharged, and the clear water after the pH value is adjusted enters the secondintermediate water tank 32 through a lift pump to be temporarily stored. After the pretreatment of the step, most of temporary hardness and permanent hardness in the water are basically removed, and the scaling of subsequent treatment equipment is avoided.

And step 3, the clarified water temporarily stored in the secondintermediate water tank 32 enters the filter 14 in sequence for filtration, and theultrafiltration system 21 performs ultrafiltration, so that suspended matters, turbidity and other impurities in the water are further removed. The filtered and ultrafiltered water flows into the clear water tank 4 for temporary storage.

And 4, feeding the clean water in the clean water tank 4 into a first-stagereverse osmosis system 22 through a water lift pump for first-stage reverse osmosis treatment (first-stage pre-desalination), and feeding a reducing agent and a scale inhibitor into a pipeline before the clean water enters the first-stagereverse osmosis system 22. The fresh water obtained by the first-stage reverse osmosis enters a first-stagefresh water tank 51 for temporary storage, then the fresh water is pumped into a second-stagereverse osmosis system 23 for secondary reverse osmosis treatment (secondary pre-desalination), the fresh water obtained by the second-stage reverse osmosis enters a second-stagefresh water tank 52 for temporary storage, and then the fresh water is pumped into anelectric desalination system 24 for desalination treatment, and because the salt content of the concentrated water generated by the second-stagereverse osmosis system 23 and the concentrated water generated by thedesalination system 24 is not high, the water quality is good, the water quantity is small, the fresh water is directly recycled to a clear water tank 4 and then participates.

All the intercepted substances in the first-stagereverse osmosis system 22 are concentrated in 25-30% of concentrated water, and the concentrated water has the characteristics of low content of suspended matters, high salt content, high alkalinity, high hardness, organic matter content, high possibility of scaling, large water quantity, occupation of 25-30% of water inflow and the like, and is wastewater which cannot be directly utilized and is most difficult to treat in the process. As the incoming water is subjected to hardness removal treatment, but 100% of hardness cannot be removed, the hardness of the outlet water in the pretreated water is 2-3 mmol/L, and the hardness of the concentrated water is about 8-12 mmol/L, so that the quality requirement of water supplement of a heat supply network cannot be met. According to the characteristics of the concentrated water and the water quality requirement of the hot network make-up water, the concentrated water is further softened and then used as the hot network make-up water. According to the requirement, the concentrated water generated by the first-levelreverse osmosis system 22 enters the reverse osmosis concentratedwater tank 61 for temporary storage and then is pumped into thesodium ion softener 25 for softening treatment, a large amount of sodium type ion softening resin is placed in thesodium ion softener 25, water replaces hardness ions in the water during passing, hardness in the water is further removed, fresh water reaching the quality standard of hot net replenishing water is prepared, the obtained softened fresh water enters the softeningwater tank 62 for storage, the softened fresh water is timely taken as the hot net replenishing water for recycling, the fresh water is not discharged and the treatment recycling is realized by adopting the most effective mode.

And 5, desalting the fresh water obtained by pre-desalting by anelectric desalting system 24 to finally prepare desalted water.

After the filter 14 and theultrafiltration system 21 in the step 3 are operated for a period of time, the pressure difference is increased, the resistance is increased, the filtering effect is reduced, the water quality of effluent is deteriorated, water backwashing or air-water backwashing needs to be carried out on a filtering layer and an ultrafiltration membrane element of the filter, a filtering layer of the backwashed filter is expanded and suspended, and the filtering layer is cleaned by means of the shearing force of water flow and the collision friction force of particles, so that dirt in the filtering layer is separated and is discharged along with backwash water, and the effluent quality of the filter is ensured. And in the backwashing ultrafiltration membrane element, backwashing water enters from the water outlet side of the membrane and is discharged from the water inlet side, the membrane shakes in the backwashing process, and pollutants are separated from the membrane and are discharged along with the backwashing water. Backwashing drainage generated by filtering is recycled to the regulatingtank 11, and after uniform mixing, the backwashing drainage is continuously subjected to two-stage clarification treatment, so that backwashing water is not discharged outside. The backwashing drainage of the filter 14 and the backwashing drainage of theultrafiltration system 21 have the characteristics of high suspended matter content and salt content similar to that of the inlet water, so that the return to the regulatingreservoir 11 is the most effective recycling mode.

After thesodium ion softener 25 in the step 4 is operated for a period of time, most of sodium ions on the ion exchanger are converted into calcium and magnesium types, the hardness of effluent is increased, the resin is invalid, and the resin needs to be regenerated to recover the exchange capacity. Sodium chloride is used as a regenerant. The sodium ion exchanger can adopt a full-automatic sodium ion exchanger, is convenient to operate, and realizes the processes of full-automatic operation, regeneration, backwashing and the like. The salt content of the regenerated drainage of the sodium ion softener is high, the water quantity is small and accounts for about 3-5% of the water inflow, so that the generated regenerated flushing drainage is recycled to the regulatingtank 11, the regenerated flushing drainage is uniformly mixed and then continuously enters two-stage clarification treatment, and the regenerated flushing water is not discharged outside, which is the most effective recycling mode.

The adjustingtank 11, theprimary clarification tank 12 and the secondary clarification tank 13 need to continuously discharge mud in the operation process. The discharged sludge flows into asludge concentration tank 71, the sludge after sludge concentration enters a dehydrator 72 for further dehydration, and after the sludge is concentrated and dehydrated by thesludge concentration tank 71 and the dehydrator 72, the water content of the sludge is about 70%, and the sludge cake is transported and recovered.

After the process, all the waste water generated in the system is recycled in the system, and the waste water which can not be directly recycled enters a heat supply network water replenishing system after being treated to reach the water quality standard of softened water. The water in the system is completely used, no waste liquid is discharged out of a factory, and waste in the water is transported and recovered in a solid form.

Specific embodiments and some parameters of an engineered power plant are given below.

The invention relates to a treatment process of a boiler make-up water treatment system of an engineering power plant by adopting a pretreatment and whole membrane method. The main water quality indexes of the incoming water to the regulatingtank 11 are as follows: suspended matter 40 mg/L, TDS about 300mg/L, pretreatment water amount 55m³Firstly, the incoming water is connected into a regulatingtank 11 through a pipeline, the recovered water and the incoming water are uniformly mixed in the regulatingtank 11 and then enter clarification tanks through a lifting water pump, the storage time of the mixed water in the regulatingtank 11 is 1-2 hours, the retention time of each clarification tank is about 1-1.5 hours, lime milk or sodium hydroxide, a coagulant and a coagulant aid are simultaneously added into aprimary clarification tank 12 in sequence, and sodium carbonate, the coagulant and the coagulant aid are simultaneously added into a secondary clarification tank 13 in sequenceThe agent, clear water after mixing, reaction and clarification flows into the middle water tanks at the downstream of the agent, temporary hardness in water is removed by adding lime milk, permanent hardness in concentrated water is removed by adding sodium carbonate, and suspended matters, organic matters and other pollutants in water are removed by adding coagulant. The effluent after the treatment is alkaline, acid is added into a main pipe at the outlet of the clarification tank to reduce the pH value of the clarified water, the clarified water with the adjusted pH value is pumped into a filter 14 and anultrafiltration system 21 through a lift pump to further remove suspended matters, impurities such as turbidity and the like in the water, and clear water generated by filtration and ultrafiltration flows into a clear water tank 4.Ultrafiltration system 21 treated water volume 48m³H, recovery 90%.

Clean water in the clean water tank 4 is pumped into the first-stagereverse osmosis system 22 through a water pump, and a reducing agent and a scale inhibitor are added before entering the first-stagereverse osmosis system 22.

The first-stagereverse osmosis system 22 comprises a first-stage security filter, a first-stage high-pressure pump and a first-stage reverse osmosis device, the incoming water is connected with the first-stage security filter through a pump and a pipeline, the first-stage security filter is connected with the first-stage high-pressure pump, the first-stage high-pressure pump is connected with the first-stage reverse osmosis device, and the treated water quantity of the first-stage reverse osmosis system 22³H, recovery 75%. The effluent of the first-stage reverse osmosis device flows into a first-stagefresh water tank 51 and is pumped into a second-stagereverse osmosis system 23 through a lift pump, the second-stagereverse osmosis system 23 comprises a second-stage security filter, a second-stage high-pressure pump and a second-stage reverse osmosis device, the first-stage fresh water tank is connected with the second-stage security filter through a pump and a pipeline, the second-stage security filter is connected with the second-stage high-pressure pump, and the second-stage. The water treated by the secondaryreverse osmosis system 23 is about 33m³H, recovery 90%. The second grade reverse osmosis unit goes out water and flows into second gradefresh water tank 52, goes intodesalination system 24 through the elevator pump, and it includes ultrafilter, electric desalination device, and second gradefresh water tank 52 passes through pump and pipe connection ultrafilter, and the ultrafilter is connected electric desalination device. The electric desalting device has a treated water volume of 30m³H, recovery 90%. The treated desalted water is used as boiler make-up water and pumped into the boiler through a lift pump. Wherein the concentrated water generated by the electric desalting and the concentrated water generated by the secondary reverse osmosis flow back to the clear water tank 4 so as to improve the utilization rate of the water. Produced by primary reverse osmosisThe concentrated water is softened and then used as the supplementary water of the heat supply network. The concentrated water generated by the first-stage reverse osmosis is about 12m³And/h, collected to the reverse osmosis concentratedwater tank 61 through a pipeline and sent to the full-automaticsodium ion softener 25 through a lifting pump. Total hardness of treated effluent<600. mu. mol/L, suspension<5 mg/L, meeting the water inlet standard requirement of the heat supply network for supplementing water, and supplementing softened water into the heat supply network through a lift pump.

And after the filter 14 and theultrafiltration system 21 operate for a period of time, backwashing is carried out, backwashing water is recycled to the regulatingtank 11 and then to the inlet of theprimary clarification tank 12, and treatment is continued without discharge. After thesodium ion softener 25 is operated for a period of time, the ion exchanger needs to be regenerated, and regenerated washing water can also be recycled to the regulatingwater tank 11 and pumped to the inlet of theprimary clarification tank 12. The concentrated water of the electric desalting device and the flow of the secondary reverse osmosis concentrated water are about 6m³And h, collecting the wastewater to a clean water tank 4 through a pipeline, and sending the wastewater to a primaryreverse osmosis system 22 through a lifting pump for further treatment.

The main equipment used in the above embodiment is specifically described below.

No matter one-level clarification tank 12 or second grade clarification tank 13 all adopts the vertical equipment of a steel structure, accomplishes simultaneously in the clarification tank and mixes, reacts and flocculates the settlement process, and the clarification tank constantly arranges mud at the operation in-process to maintain normal use.

The filter 14 is a vertical cylindrical container with a steel structure, and filter materials are placed in the vertical cylindrical container to remove suspended matters, so that the purpose of purifying water quality is achieved. The filter material of the filter can adopt fine sand, double filter material and the like, and the form of the filter can adopt full-automatic filter, pressure type filter or gravity type filter and other filter equipment. When the filter 14 operates for a period of time, backwashing is performed according to the pressure difference between the inlet and the outlet, and the filter is continuously used after backwashing.

Ultrafiltration is a pressurized membrane separation technique, i.e. under a certain pressure, small molecular solutes and solvents pass through a special membrane with a certain pore diameter, while large molecular solutes cannot permeate and remain on one side of the membrane, thereby purifying water and effectively removing bacteria, suspended substances, colloids and other impurities in the water. The system recovery rate of the ultrafiltration equipment is high, the water quality and the quality of the product water are excellent, and the high-efficiency separation of materials can be realized. Advanced process design, high integration degree, compact structure, small occupied area, simple and convenient operation and maintenance and low labor intensity of workers. The method is widely applied to water treatment systems. In this embodiment, the ultrafiltration device is an immersion type or external pressure type ultrafiltration device.

Reverse osmosis is a membrane separation operation that uses a pressure differential as a driving force to separate a solvent from a solution. The reverse osmosis can intercept various inorganic ions, colloidal substances and macromolecular solutes in water, so that the prepared pure deionized water has a desalting rate of 95-98%. Reverse osmosis has the advantages of low energy consumption, high efficiency and the like, and is one of membrane separation technologies with wide application. The first-stage reverse osmosis device in this embodiment is a first-stage two-stage reverse osmosis device.

The fresh water treated by reverse osmosis can not meet the requirement of boiler make-up water, and needs to be subjected to electric desalting treatment continuously. The electric desalting device is a pure water manufacturing technology combining an ion exchange technology, an ion exchange membrane technology and an ion electromigration technology. The charged ions in the water are moved by utilizing the high voltage of the electrodes at the two ends, and the removal of the ions is accelerated by matching with the ion exchange resin, so that the aim of completely desalting the water is fulfilled. The quality of the effluent produced by electric desalting has silicon dioxide of less than 10 mug/L and conductivity (25 ℃) of less than 0.10 muS/cm.

Thesodium ion softener 25 is a vertical cylindrical container, and the container is made of steel and lined with glue for corrosion prevention, or made of glass fiber reinforced plastic and placed with sodium ion exchange resin, so that the aim of removing cations such as calcium ions, magnesium ions and the like in water is fulfilled. The sodium ion softener in the embodiment can adopt conventional sodium ion softeners, full-automatic sodium ion softeners and other softening equipment. When the ion exchanger operates for a period of time, the resin will lose effectiveness, and sodium chloride is needed to regenerate the resin, and the resin is washed clean by water to recover the exchange capacity and continue to be used.

Impurities and ions in the incoming water can be removed through the system and the process, the requirement of the boiler make-up water quality is met, and the water quality reaches the standard of heat supply network make-up water after the reverse osmosis concentrated water is softened. Under the normal operation condition, all the waste water produced in the system is used and treated in the system, and the waste water is not discharged, thereby achieving the requirement of zero discharge of the waste water.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings and examples, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications may be made to the technical solution of the invention, and in order to avoid unnecessary repetition, various possible combinations of the invention will not be described further. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.

Claims (10)

Translated fromChinese

1.一种将全膜法做到废水零排放的处理系统，其特征在于，包括预处理系统（1）和全膜法水处理系统（2）：1. A treatment system for achieving zero discharge of waste water by an all-membrane method, characterized in that it comprises a pretreatment system (1) and an all-membrane method water treatment system (2):预处理系统（1）包含顺次连接的调节池（11）、澄清池、过滤器（14），所述澄清池设有碱加药装置、混凝剂投加装置和助凝剂投加装置，澄清池的出口管路上设有酸加药装置；The pretreatment system (1) includes a conditioning tank (11), a clarifier, and a filter (14) connected in sequence, and the clarifier is provided with an alkali dosing device, a coagulant dosing device, and a coagulant dosing device. , There is an acid dosing device on the outlet pipeline of the clarifier;所述全膜法水处理系统（2）包含顺次连接的超滤系统（21）、一级反渗透系统（22）、二级反渗透系统（23）、电除盐系统（24），所述过滤器（14）的出口连接于超滤系统（21）的入口，所述一级反渗透系统（22）的入口前设有还原剂投加装置和阻垢剂投加装置，所述二级反渗透系统（23）的二级反渗透浓水出口、电除盐系统（24）的浓水出口均返回连接于还原剂投加装置和阻垢剂投加装置之前，一级反渗透浓水系统（22）的一级反渗透浓水出口连接钠离子软化器（25），该钠离子软化器（25）软化水出口返回热网回用；The all-membrane water treatment system (2) comprises an ultrafiltration system (21), a primary reverse osmosis system (22), a secondary reverse osmosis system (23), and an electric desalination system (24) connected in sequence, so The outlet of the filter (14) is connected to the inlet of the ultrafiltration system (21), and a reducing agent dosing device and a scale inhibitor dosing device are provided in front of the inlet of the primary reverse osmosis system (22). The secondary reverse osmosis concentrated water outlet of the secondary reverse osmosis system (23) and the concentrated water outlet of the electric desalination system (24) are all returned and connected to the reducing agent dosing device and the scale inhibitor dosing device. The primary reverse osmosis concentrated water outlet of the water system (22) is connected to the sodium ion softener (25), and the softened water outlet of the sodium ion softener (25) returns to the heating network for reuse;所述过滤器（14）的反洗排水口、超滤系统（21）的反洗排水口以及钠离子软化器（25）的再生冲洗排水口均返回连接于所述调节池（11）。The backwash drain of the filter (14), the backwash drain of the ultrafiltration system (21), and the regeneration flush drain of the sodium ion softener (25) are all returned and connected to the conditioning tank (11).2.如权利要求1所述的一种将全膜法做到废水零排放的处理系统，其特征在于，所述澄清池为顺次布置的一级澄清池（12）和二级澄清池（13），所述一级澄清池（12）设有第一碱加药装置、二级澄清池（13）设有第二碱加药装置，该一级澄清池（12）、二级澄清池（13）均设有混凝剂加药装置和助凝剂加药装置，所述酸加药装置位于二级澄清池（13）的澄清水（13）出口，所述调节池（11）设有杀菌剂投加装置。2. A treatment system for realizing zero discharge of wastewater by the full-membrane method according to claim 1, wherein the clarifier is a primary clarifier (12) and a secondary clarifier (12) arranged in sequence. 13), the primary clarifier (12) is provided with a first alkali dosing device, the secondary clarifier (13) is provided with a second alkali dosing device, the primary clarifier (12), the secondary clarifier (13) Both are provided with a coagulant dosing device and a coagulation aid dosing device, the acid dosing device is located at the outlet of the clarified water (13) of the secondary clarifier (13), and the regulating pool (11) is provided with There is a bactericide dosing device.3.如权利要求2所述的一种将全膜法做到废水零排放的处理系统，其特征在于，所述一级澄清池（12）与二级澄清池（13）之间设有第一中间水箱（31），所述二级澄清池（13）与过滤器（14）之间设有第二中间水箱（32），所述酸加药装置设于该第二中间水箱（32）的入口前。3. A treatment system for achieving zero discharge of wastewater by the full membrane method according to claim 2, wherein a second clarifier is provided between the primary clarifier (12) and the secondary clarifier (13). An intermediate water tank (31), a second intermediate water tank (32) is arranged between the secondary clarifier (13) and the filter (14), and the acid dosing device is arranged in the second intermediate water tank (32) before the entrance.4.如权利要求1所述的一种将全膜法做到废水零排放的处理系统，其特征在于，所述超滤系统（21）与一级反渗透系统（22）之间设有清水箱（4），所述二级反渗透系统（23）的二级反渗透浓水出口、电除盐装置（24）的浓水出口均返回连接于该清水箱（4），所述还原剂投加装置和阻垢剂投加装置设置于该清水箱（4）出口后；4. A treatment system for achieving zero discharge of waste water by an all-membrane method according to claim 1, wherein clean water is provided between the ultrafiltration system (21) and the primary reverse osmosis system (22). tank (4), the secondary reverse osmosis concentrated water outlet of the secondary reverse osmosis system (23) and the concentrated water outlet of the electric desalination device (24) are all returned and connected to the clean water tank (4), the reducing agent The dosing device and the scale inhibitor dosing device are arranged behind the outlet of the clean water tank (4);所述一级反渗透系统（22）与第二反渗透系统（23）之间设有一级淡水箱（51），所述二级反渗透系统（23）与电除盐系统（24）之间设有二级淡水箱（52），所述电除盐系统（24）的除盐水出口设置除盐水箱（53）。A first-stage fresh water tank (51) is arranged between the first-stage reverse osmosis system (22) and the second reverse osmosis system (23), and between the second-stage reverse osmosis system (23) and the electric desalination system (24) A secondary fresh water tank (52) is provided, and a demineralized water tank (53) is provided at the demineralized water outlet of the electric desalination system (24).5.如权利要求1至4任一所述的一种将全膜法做到废水零排放的处理系统，其特征在于，所述一级反渗透装置（22）与钠离子软化器（25）之间设有反渗透浓水箱（61），所述钠离子软化器（25）的软化水出口连接软化水箱（62），该软化水箱（62）出口返回热网回用。5. A treatment system for achieving zero discharge of waste water by an all-membrane method according to any one of claims 1 to 4, characterized in that the primary reverse osmosis device (22) and the sodium ion softener (25) There is a reverse osmosis concentrated water tank (61) in between, the softened water outlet of the sodium ion softener (25) is connected to the softened water tank (62), and the softened water tank (62) outlet is returned to the heat grid for reuse.6.如权利要求2所述的一种将全膜法做到废水零排放的处理系统，其特征在于，所述第一碱加药装置为石灰或氢氧化钠加药装置，所述第二碱加药装置为碳酸钠加药装置。6. a kind of treatment system that achieves zero discharge of waste water by full membrane method as claimed in claim 2, it is characterized in that, described first alkali dosing device is lime or sodium hydroxide dosing device, and the second The alkali dosing device is a sodium carbonate dosing device.7.一种将全膜法做到废水零排放的处理工艺，其特征在于，应用如权利要求1至6所述的一种将全膜法做到废水零排放的处理系统，至少包含如下步骤：7. a process for treating zero discharge of waste water by full-film method is characterized in that, applying a treatment system of zero-discharge of waste water by full-film method as claimed in claims 1 to 6, comprising at least the following steps :步骤1，来水进入调节池（11），与其他回收水混合均匀；Step 1, the incoming water enters the regulating tank (11) and is evenly mixed with other recycled water;步骤2，步骤1获得的混合水顺次进入至少一级澄清池，通过该至少一级澄清池进行混凝、澄清、除硬度的处理；In step 2, the mixed water obtained in step 1 enters into at least one level of clarifier in turn, and the treatment of coagulation, clarification and removal of hardness is carried out through the at least one level of clarifier;步骤3，步骤2获得的澄清水顺次通过过滤器（14）进行过滤、超滤系统21进行超滤，去除悬浮物，获得清水；Step 3, the clarified water obtained in step 2 is filtered through the filter (14) in turn, and the ultrafiltration system 21 is subjected to ultrafiltration to remove suspended solids and obtain clean water;步骤4，步骤3获得的清水顺次进入一级反渗透系统（22）、二级反渗透系统（23），经过两级反渗透，进行预脱盐处理，获得淡水；In step 4, the clean water obtained in step 3 enters the primary reverse osmosis system (22) and the secondary reverse osmosis system (23) in sequence, and undergoes pre-desalination treatment through the two-stage reverse osmosis to obtain fresh water;步骤5，步骤4获得的淡水经过电除盐系统（24）进行除盐处理，最终制成除盐水；In step 5, the fresh water obtained in step 4 is subjected to desalination treatment by the electric desalination system (24), and finally demineralized water is made;上述步骤3中，将过滤器（14）、超滤系统（21）产生的反洗排水回收至调节池（11），混合均匀后进行处理再利用；In the above-mentioned step 3, the backwashing drainage generated by the filter (14) and the ultrafiltration system (21) is recycled to the adjustment tank (11), and the mixture is uniformly processed and reused;上述步骤4中，一级反渗透产生的浓水进行钠离子软化处理后，获得的软化水用于热网补充水，钠离子软化处理产生的再生冲洗排水回收至调节池（11），混合均匀后进行处理再利用，二级反渗透产生的浓水和电除盐处理产生的浓水回收至一级反渗透系统（22），再次参与预脱盐处理。In the above step 4, after the concentrated water produced by the first-stage reverse osmosis is subjected to sodium ion softening treatment, the obtained softened water is used for supplementary water of the heat network, and the regeneration flushing drainage generated by the sodium ion softening treatment is recycled to the adjustment tank (11), and mixed evenly. After treatment and reuse, the concentrated water produced by the secondary reverse osmosis and the concentrated water produced by the electric desalination treatment are recycled to the primary reverse osmosis system (22), and participate in the pre-desalination treatment again.8.如权利要求7所述的一种将全膜法做到废水零排放的处理工艺，其特征在于，所述步骤1中的混合水在调节池（11）经过曝气和杀菌处理；8. A treatment process for achieving zero discharge of waste water by the all-membrane method according to claim 7, wherein the mixed water in the step 1 is subjected to aeration and sterilization treatment in the regulating tank (11);所述步骤2中，混合水顺次经过一级澄清池（12）、二级澄清池（13），混合水进入一级澄清池（12）后，投加石灰或氢氧化钠、混凝剂、助凝剂，所获得的澄清水进入二级澄清池后，投加碳酸钠、混凝剂、助凝剂，所获得的澄清水呈碱性，在澄清水排出后投加酸以降低pH值，调整pH值后的澄清水再进行步骤3；In the step 2, the mixed water passes through the primary clarifier (12) and the secondary clarifier (13) in sequence, and after the mixed water enters the primary clarifier (12), lime or sodium hydroxide and coagulant are added. , coagulation aid, after the obtained clarified water enters the secondary clarifier, sodium carbonate, coagulant and coagulation aid are added, the obtained clarified water is alkaline, and acid is added after the clarified water is discharged to reduce pH value, the clarified water after adjusting the pH value goes to step 3;所述步骤3中，超滤系统（21）产生的清水先进入清水箱（4），二级反渗透系统（23）产生的浓水和电除盐系统（24）产生的浓水返回该清水箱（4），在清水箱（4）的出口管路中顺次投加还原剂和阻垢剂，混合后进入一级反渗透系统（22）。In the step 3, the clean water produced by the ultrafiltration system (21) first enters the clean water tank (4), and the concentrated water produced by the secondary reverse osmosis system (23) and the concentrated water produced by the electric desalination system (24) are returned to the clean water. tank (4), the reducing agent and scale inhibitor are sequentially added to the outlet pipeline of the clean water tank (4), and after mixing, enter the primary reverse osmosis system (22).9.如权利要求7所述的一种将全膜法做到废水零排放的处理工艺，其特征在于，调节池（11）的储存时间为1～2小时，每个澄清池的停留时间1-1.5小时。9 . The treatment process according to claim 7 , characterized in that the storage time of the conditioning tank ( 11 ) is 1 to 2 hours, and the residence time of each clarifier is 1 -1.5 hours.10.如权利要求7至9任一所述的一种将全膜法做到废水零排放的处理工艺，其特征在于，调节池（11）、至少一级澄清池排泥且经浓缩、脱水后制成泥饼，作为固体回收。10. The treatment process for achieving zero discharge of wastewater by a full-membrane method according to any one of claims 7 to 9, characterized in that the adjustment tank (11) and at least one-level clarifiers discharge sludge and are concentrated and dehydrated After the mud cake is made, it is recovered as a solid.

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