CN115849597A - Nickel-containing wastewater treatment system and use method thereof - Google Patents

Abstract

The application relates to the technical field of wastewater treatment systems, and particularly discloses a nickel-containing wastewater treatment system and a using method thereof. A nickel-containing wastewater treatment system comprises a pretreatment system and a desalting system; the pretreatment system comprises: a nickel-containing wastewater adjusting tank, a pH adjusting tank, a pre-settling tank and an intermediate water tank; the desalination system comprises: the device comprises a multi-medium filter, an ultrafilter, an ultrafiltration water tank, a nanofiltration water tank, a reverse osmosis device and a reverse osmosis water tank. The utility model provides a wastewater treatment system can be used to handle nickel-containing waste water such as electroplating, industry, and it has the treatment cost low, efficient to getting rid of nickel, advantage that waste water recovery is high.

Description

Nickel-containing wastewater treatment system and use method thereof

Technical Field

The application relates to the technical field of nickel-containing wastewater treatment systems, in particular to a nickel-containing wastewater treatment system and a using method thereof.

Background

The industrial sources of nickel waste water are mainly electroplating industry, and mining metallurgical waste water also contains nickel, and the nickel in the waste water mainly exists in the form of divalent ions, such as nickel sulfate and nickel salt substances generated with inorganic organic complexes.

The nickel-containing wastewater is difficult to treat, and methods for treating the nickel-containing wastewater comprise a micro-electro lime precipitation or sulfide precipitation method, an ion exchange method, a reverse osmosis method, an evaporation recovery method and the like.

In order to meet the discharge standard with higher requirements in most of the existing wastewater treatment processes in the prior art, the conventional treatment method is to perform further advanced treatment by processes such as electrodialysis, MVR evaporation and the like after flocculation treatment, so that the number of treatment units is increased, and the treatment cost is greatly increased.

Disclosure of Invention

In order to overcome the defects of more treatment units and high treatment cost of the existing treatment process, the application provides a nickel-containing wastewater treatment system and a using method thereof.

In a first aspect, the present application provides a nickel-containing wastewater treatment system, which adopts the following technical scheme:

a nickel-containing wastewater treatment system comprises a pretreatment system and a desalting system;

the pretreatment system comprises: a nickel-containing wastewater adjusting tank, a pH adjusting tank, a pre-settling tank and an intermediate water tank;

the desalination system comprises: the device comprises a multi-medium filter, an ultrafilter, an ultrafiltration water tank, a nanofiltration water tank, a reverse osmosis device and a reverse osmosis water tank.

Through adopting above-mentioned technical scheme, this application technical scheme preferably adopts materialization-embrane method to handle waste water, and nickeliferous waste water carries to the pH equalizing basin in adjusting balanced back, adds the alkali regulation and carries out the preliminary sedimentation, gets rid of great suspended solid and particulate matter etc. in the waste water, after the preliminary sedimentation goes out water, carries the supernatant to many medium filter in, through the ultrafiltration, reduces the SDI of waste water, and the most dissolved univalent, polyvalent inorganic salt is got rid of through receiving and receiving nanofiltration, reverse osmosis again, further circulation is concentrated, reduces the content of nickel ion in the waste water. Through the two-stage filtration treatment of nanofiltration and reverse osmosis, high desalination rate is obtained while high recovery rate is maintained, and the reverse osmosis system can still ensure that the quality of the outlet water is excellent under the condition of large fluctuation of the inlet water.

In this application, the waste water treatment unit is few, reduces the production of mud, and automatic control can be adopted to the full flow, has effectively reduced treatment cost and treatment effect is good.

Preferably, the ultrafilter comprises an ultrafiltration membrane, and the ultrafiltration membrane is a membrane with carbon nanotubes loaded on the surface.

Through adopting above-mentioned technical scheme, preferably adopting in this application technical scheme loads carbon nanotube on ultrafiltration membrane surface, because carbon nanotube has good high specific surface area and adsorptivity for the pore structure and the interface roughness on ultrafiltration membrane surface all change, the entanglement between the carbon nanotube fibre forms the interweave layer that has more space, makes the water flux of ultrafiltration membrane maintain basically. But the roughness of the surface of the ultrafiltration membrane is obviously improved, the interaction between the ultrafiltration membrane and pollutants is reduced, the polar force repulsion effect between the ultrafiltration membrane and the pollutants is also increased, the possibility of loading the pollutants on the ultrafiltration membrane is reduced, the ultrafiltration membrane is easy to recover to be clean in the backwashing process, and the filtering effect of the filtration membrane is improved.

Preferably, the preparation method of the ultrafiltration membrane comprises the following steps: and (2) taking the graphene dispersion liquid and the PVA dispersion liquid according to the mass ratio of 1.

Preferably, the spraying amount of the carbon nanotubes is 10 to 20mg.

By adopting the technical scheme, PVA is preferably adopted as a cross-linking agent in the technical scheme, the polyvinyl alcohol is in cross-linking combination with the groups on the carbon nano tubes, the carbon nano tubes are assisted to form a staggered network structure on the surface of the ultrafiltration membrane, namely, a interwoven layer with more pore structures is formed, the ultrafiltration membrane is endowed with proper hydrophilicity, the ultrafiltration membrane obtains better water flux and interface roughness, and the anti-pollution effect of the ultrafiltration membrane is improved.

In the technical scheme, the spraying amount of the carbon nano tubes is optimized, and the proper spraying amount of the carbon nano tubes enables the ultrafiltration membrane to obtain an excellent anti-pollution effect and a flux recovery effect.

Preferably, the nanofiltration membrane is included in the nanofiltration device, the nanofiltration membrane is an anti-pollution nanofiltration membrane, and the preparation of the anti-pollution nanofiltration membrane comprises the following steps: dipping the ultrafiltration membrane into the water phase solution, taking out, dipping the ultrafiltration membrane into the oil phase, carrying out heat treatment in an oven, taking out, and soaking in the reverse osmosis water solution to obtain the anti-pollution nanofiltration membrane; wherein the water phase comprises the following substances in parts by weight: 0.01-0.03 parts of reactive monomers consisting of 60-80% of l-arginine and 20-40% of piperazine, 0.03 parts of triethylamine and 1 part of water; the oil phase comprises TMC-n-hexane with the mass concentration of 0.001-0.002 g/mL.

By adopting the technical scheme, arginine is preferably matched with TMC in the technical scheme, and is introduced into the selective separation layer of the nanofiltration membrane through interfacial polymerization, so that the hydrophilicity and the electronegativity of the nanofiltration membrane are improved by introducing the arginine. Meanwhile, due to hydrogen bond interaction and electrostatic attraction between piperazine and arginine, free diffusion of piperazine is hindered, an irregular ridge-valley structure is formed on the surface of the nanofiltration membrane, the loading capacity of arginine on the surface of the nanofiltration membrane is improved, and the hydrophilicity of the nanofiltration membrane is improved. In addition, due to the matching of arginine and piperazine, the permeability and the southward effect of the nanofiltration membrane are improved, so that the rejection rate of the nanofiltration membrane on sulfate radicals is effectively improved.

Simultaneously, having optimized the addition of arginine and piperazine among the application technical scheme, not only can maintain compact, complete and flawless nanofiltration membrane, can also strengthen the hydrophilic effect of nanofiltration membrane, reduce the osmotic resistance of water, that is to say, improved the filter effect of nanofiltration membrane to waste water.

Preferably, the water phase comprises the following materials in parts by weight: 0.01-0.03 part of reaction monomer, 0.0015 part of catalyst A and 1 part of water, wherein the reaction monomer comprises ethyl 2- (2-bromoisobutyloxy) acrylate, sulfobetaine, polydisiloxane, a complexing agent and a catalyst B.

By adopting the technical scheme, the zwitterionic polymer can be formed by the reaction of all components in the reaction monomer in the technical scheme, the zwitterionic polymer is introduced into the nanofiltration membrane through the interfacial polymerization reaction, and the zwitterionic polymer reacts with TMC, and acyl chloride groups in the TMC groups are hydrolyzed into carboxyl groups, so that the water throughput of the nanofiltration membrane is improved, the nanofiltration membrane is electronegative, and the rejection rate of the nanofiltration membrane to sulfate radicals is improved.

Preferably, the reverse osmosis device comprises a reverse osmosis membrane, and the reverse osmosis membrane is a silver-loaded reverse osmosis membrane treated by tannic acid.

Through adopting above-mentioned technical scheme, adopt tannic acid to handle reverse osmosis membrane among this application technical scheme, because tannic acid has good oxidation resistance, hydrophilicity and metal ion chelating ability, through tannic acid's reducibility with silver nanoparticle introduction reverse osmosis membrane's intermediate level, not only can maintain reverse osmosis membrane's selective permeability, can also improve reverse osmosis membrane's biological pollution resistant effect.

Through reducing the roughness on reverse osmosis membrane surface for reverse osmosis membrane surface approaches neutral, when organic matter pollutes and is close to, through steric effect and energy barrier, reduces the possibility of pollutant adhesion on reverse osmosis membrane. And the silver nanoparticles have better sterilization effect, so that the effect of killing microorganisms by the reverse osmosis membrane can be further improved, the excellent selective permeability of the reverse osmosis membrane is maintained, and the cleaning effect of the reverse osmosis membrane is improved.

Preferably, the system further comprises an adsorption treatment system, wherein the adsorption treatment system comprises an adsorption tank, and an adsorbent is filled in the adsorption tank and is selected from any one or two of sepiolite, steel slag and ion resin.

Through adopting above-mentioned technical scheme, among this application technical scheme, add post-treatment system in processing system, the waste water that will be handled through the desalination system adsorbs the processing through the adsorbent in the adsorption tank again, further adsorbs nickel ion etc. in to aquatic, further reduces the content of metallic ion in the waste water, improves the cyclic utilization of the waste water after handling. The sepiolite and the steel slag both have more pore structures and larger specific surface areas, so that the sepiolite and the steel slag both have better adsorption performance and can adsorb a small amount of nickel ions in reverse osmosis treatment. The ion resin can adsorb nickel ions in the water subjected to reverse osmosis treatment through ion exchange, so that the content of the nickel ions in the wastewater is further reduced, and the recycling efficiency of the wastewater is improved.

Preferably, the sepiolite is processed by magnetic modification, and the preparation of the sepiolite comprises the following steps: putting the sepiolite into the modification liquid, stirring and mixing, aging, cleaning, performing magnetic separation to realize solid-liquid separation, and drying to obtain the modified sepiolite; the modifying liquid comprises ferrous sulfate tetrahydrate and ferric chloride hexahydrate.

Through adopting above-mentioned technical scheme, sepiolite is every kind of discontinuous octahedron of two-layer continuous silicon oxygen tetrahedron centre gripping one deck, has great specific surface area and pore volume, and the inside negative pressure of sepiolite is great, and the adsorptivity is stronger, can effectively adsorb the nickel ion in the waste water. After the sepiolite is subjected to magnetic modification treatment, the sepiolite is not easy to swell due to water absorption and rheological property, can be separated conveniently and quickly in a magnetic separation mode, maintains the excellent adsorption effect of the sepiolite, and effectively separates and adsorbs the saturated sepiolite.

Preferably, the steel slag is pretreated steel slag, and the pretreatment comprises the following steps: crushing the steel slag to ensure that the particle size of the steel slag is less than 5mm, dissolving the steel slag and the scrap iron in dilute hydrochloric acid and dilute nitric acid, stirring for reaction, and aging to obtain the pretreated steel slag.

Through adopting above-mentioned technical scheme, carry out crushing treatment to the slag in advance among this application technical scheme, suitable particle diameter makes the specific surface area and the surface energy of slag great, is favorable to going on of absorption, has improved the adsorption effect of adsorbent remaining nickel ion in to the waste water promptly.

Iron polysilicate can be formed through the matching reaction of iron scraps and steel slag, the high molecular weight iron polysilicate has extremely strong adsorption and bridging capacity, the flocculation effect of the adsorbent is further improved, the content of nickel ions in wastewater is reduced, the polymerization inhibition effect of metal ions at the chain end in the iron polysilicate provides higher surface charges, an electric double layer of impurities is effectively compressed, the surface charges are reduced, and the adsorption effect of the iron polysilicate is further promoted.

In addition, the steel slag and the scrap iron are waste, a small amount of nickel ions in the wastewater are adsorbed by the waste, the purification effect of the wastewater is further improved, and the cost of the adsorbent is low.

In a second aspect, the application provides a use method of a nickel-containing wastewater treatment system, which adopts the following technical scheme:

a method for using a nickel-containing wastewater treatment system comprises the following steps:

s1, pretreatment: allowing the nickel-containing wastewater to enter a pH adjusting tank, adding alkali for adjustment, performing coagulative precipitation by using Jining in a preliminary sedimentation tank, conveying the supernatant to an intermediate water tank, and performing further sedimentation in the intermediate water tank to obtain an intermediate solution;

s2, desalting treatment: and (3) conveying the intermediate solution into a multi-medium filter, sequentially carrying out ultrafiltration, nanofiltration and reverse osmosis to obtain filtrate, conveying the filtrate into an ultrafiltration water tank again, carrying out nanofiltration and reverse osmosis again, and outputting into a reverse osmosis water tank to obtain treated wastewater.

Preferably, the pH is adjusted to 5.0-5.5.

Through adopting above-mentioned technical scheme, optimized among this application technical scheme the treatment step in preliminary treatment and the desalination processing, the waste water through reverse osmosis treatment is intake to the super filter once more, further improves the removal effect of nickel ion in the waste water. Meanwhile, the pH is optimized in the technical scheme, the appropriate pH can reduce the dosage of wastewater during adjustment, and the treatment cost is reduced.

In summary, the present application has the following beneficial effects:

1. the method comprises the steps of treating the wastewater by a physicochemical-membrane method, conveying the nickel-containing wastewater into a pH adjusting tank after the nickel-containing wastewater is adjusted and balanced, adding alkali for adjusting and pre-precipitating to remove larger suspended matters, particulate matters and the like in the wastewater, conveying supernatant into a multi-media filter after pre-precipitating to obtain water, reducing SDI of the wastewater by ultrafiltration, removing most of dissolved monovalent and polyvalent inorganic salts by nanofiltration and reverse osmosis, and further circularly concentrating to reduce the content of nickel ions in the wastewater. Through nanofiltration and reverse osmosis two-stage filtration treatment, high recovery rate is maintained, high desalination rate is obtained, a reverse osmosis system is arranged, water quality of outlet water can be ensured to be excellent under the condition of large fluctuation of incoming water, a few wastewater treatment units are provided, sludge is reduced, automatic control can be adopted in the whole process, treatment cost is effectively reduced, and the treatment effect is excellent.

2. In the application, PVA is preferably adopted as a cross-linking agent, the polyvinyl alcohol is in cross-linking combination with groups on the carbon nano tubes, the carbon nano tubes are assisted to form a staggered network structure on the surface of the ultrafiltration membrane, namely, a interwoven layer with more pore structures is formed, and the ultrafiltration membrane is endowed with proper hydrophilicity, so that the ultrafiltration membrane obtains better water flux and interface roughness, and the anti-pollution effect of the ultrafiltration membrane is improved.

3. Arginine and TMC are matched, and are introduced into a selective separation layer of the nanofiltration membrane through interfacial polymerization reaction, so that the hydrophilicity and the electronegativity of the nanofiltration membrane are improved through the introduction of the arginine. Meanwhile, due to hydrogen bond interaction and electrostatic attraction between piperazine and arginine, free diffusion of piperazine is hindered, an irregular ridge-valley structure is formed on the surface of the nanofiltration membrane, the loading capacity of arginine on the surface of the nanofiltration membrane is improved, and the hydrophilicity of the nanofiltration membrane is improved. In addition, due to the matching of arginine and piperazine, the permeability and the southward effect of the nanofiltration membrane are improved, so that the rejection rate of the nanofiltration membrane on sulfate radicals is effectively improved. Meanwhile, the addition amounts of arginine and piperazine are optimized, so that the compact and complete nanofiltration membrane without defects can be maintained, the hydrophilic effect of the nanofiltration membrane can be enhanced, and the osmotic resistance of water can be reduced.

Drawings

Fig. 1 is a flow chart of a method provided herein.

Detailed Description

The present application will be described in further detail with reference to examples.

Preparation example

Preparation of Ultrafiltration Membrane

Preparation example 1

0.1kg of multi-walled carbon nano-tube containing carboxyl functional groups and 1kg of sodium dodecyl benzene sulfonate are dispersed in absolute ethyl alcohol, and are subjected to ultrasonic dispersion for 60min to prepare 2g/L of carbon nano-tube dispersion liquid. 1g of polyvinyl alcohol is dispersed in deionized water and stirred at 95 ℃ to prepare 0.01 percent polyvinyl alcohol solution. Spraying 2.5mL of carbon nanotube dispersion liquid on the surface of the polyethersulfone ultrafiltration membrane, spraying 0.4L of polyvinyl alcohol solution on the surface of the polyethersulfone ultrafiltration membrane, carrying out deionization washing, and drying at 105 ℃ to obtain the ultrafiltration membrane 1.

Preparation example 2

The difference from preparation example 1 is that: and (3) spraying 2.5mL of carbon nanotube dispersion liquid on the surface of the polyether sulfone ultrafiltration membrane, spraying 0.45L of polyvinyl alcohol solution on the surface of the polyether sulfone ultrafiltration membrane, carrying out deionization washing, and drying at 105 ℃ to obtain the ultrafiltration membrane 2.

Preparation example 3

The difference from preparation example 1 is that: spraying 2.5mL of carbon nanotube dispersion liquid on the surface of the polyethersulfone ultrafiltration membrane, spraying 0.5L of polyvinyl alcohol solution on the surface of the polyethersulfone ultrafiltration membrane, carrying out deionization washing, and drying at 105 ℃ to obtain the ultrafiltration membrane 3.

Preparation of nanofiltration Membrane

Preparation examples 4 to 6

Taking 2g of L-arginine and 8g of piperazine to obtain a reaction monomer. Taking a reaction monomer, triethylamine and water, dispersing arginine and piperazine with water respectively to obtain a first dispersion liquid and a second dispersion liquid, and mixing the first dispersion liquid, the second dispersion liquid and the triethylamine to obtain an aqueous phase solution. 0.001g/mL of TMC-orthosilane oil phase solution is taken. Soaking the polyethersulfone nanofiltration membrane in the aqueous phase solution for 5min, pouring off the aqueous phase solution, and rolling until no obvious water drops are on the surface of the membrane. Immersing the membrane in the oil phase solution, pouring off the oil phase solution after 1min, placing the membrane in an oven, performing heat treatment at 60 ℃ for 1min, taking out the membrane, immersing in reverse osmosis water again, soaking for 24h, and drying to obtain the nanofiltration membrane 1-3.

Wherein, the mass ratio of L-arginine to piperazine may be 8, may also be 7, may also be 6.

TABLE 1 preparation examples 4-6 compositions of aqueous solutions

Preparation example 7

The difference from preparation example 4 is that: and (3) taking 0.0015g/mL of TMC-orthosilane oil-phase solution to replace the oil-phase solution in the preparation example 4 to prepare a nanofiltration membrane 4.

Preparation example 8

The difference from preparation example 4 is that: nanofiltration membrane 5 was prepared by using 0.0015g/mL TMC-n-silane oil phase solution instead of the oil phase solution of preparation example 4.

Preparation examples 10 to 12

The difference from preparation example 4 is that: mixing 2-bromine isobutyryl bromide and hydroxyethyl acrylate, dissolving in tetrahydrofuran, reacting for 24h, washing, purifying, and drying to obtain 2- (2-Bromine Isobutyloxy) Ethyl Acrylate (BIEA). Dissolving BIEA and Polydimethylsiloxane (PDMS) in dichloromethane, reacting for 48h, cleaning, purifying, and drying to obtain substance P. Dissolving Sulfobetaine (SBMA), substance P, 2-bipyridine and pentamethyldiethylenetriamine in a volume ratio of 1:1 methanol aqueous solution, reacting for 40h, and then separating, purifying and drying to obtain the zwitterionic polymer.

Immersing the hydrophilic PTFE membrane into an aqueous solution of 2-methyl-1, 3-propanediol (MPD), taking out, and wiping off residual excess solution on the surface of the membrane. And (3) soaking the membrane in the oil phase solution, taking out the membrane after 1min, volatilizing the residual organic solvent on the surface, and putting the membrane into a vacuum oven for heat treatment to obtain the composite nanofiltration membrane.

And mixing the zwitterionic polymer, triethylamine and water to prepare an aqueous phase solution. And (3) soaking the composite nanofiltration membrane in the water phase solution for 5min, taking out, soaking in the oil phase solution again for 1min, taking out, and drying to obtain the nanofiltration membrane 6-8.

TABLE 2 preparation examples 10-12 compositions of aqueous solutions

Preparation of reverse osmosis Membrane

Preparation example 13

Immersing a reverse osmosis membrane in 0.1% NaClO aqueous solution, taking out, washing with water, immersing the reverse osmosis membrane in 0.06L of 0.8g/L tannic acid solution for 2min, pouring off the tannic acid aqueous solution, immersing the reverse osmosis membrane in 0.06L of 0.2g/L of ferric chloride aqueous solution, fully soaking for 20min, pouring off the ferric chloride aqueous solution, and washing with pure water. And then soaking the reverse osmosis membrane in 0.06L of 1g/L silver nitrate aqueous solution until AgNPs are generated on the membrane surface, pouring out the silver nitrate solution, and rolling a diameter roller to obtain the reverse osmosis membrane.

Example of preparation of sepiolite

Preparation example 14

4.72kg of ferrous sulfate tetrahydrate and 7.56kg of ferric chloride hexahydrate are prepared to obtain a mixed solution with the total iron concentration of 0.7 mol/L. Soaking 1kg of sepiolite in 10L of mixed solution, stirring for 1h at 60 ℃, adding ammonia water, adjusting the pH to 9, continuing stirring for 1h, aging for 2h, washing until the washing liquid is neutral, carrying out magnetic separation, carrying out solid-liquid separation, carrying out 60 ℃ Hongan, grinding, and sieving with a 100-mesh sieve to obtain the magnetically modified sepiolite.

Examples of production of Steel slag

Preparation example 15

Crushing the steel slag, and sieving the crushed steel slag with a 100-mesh sieve to obtain the crushed steel slag. Dissolving broken steel slag and scrap iron in dilute hydrochloric acid and dilute nitric acid, loading into a reactor of an anchor stirrer, reacting at 80 ℃ for 3-4h to obtain a reddish-brown liquid, and aging for 24h to obtain the modified steel slag.

Examples

Example 1

In one aspect, the present application provides a nickel-containing wastewater treatment system, comprising a pretreatment system and a desalination system;

the pretreatment system comprises: a nickel-containing wastewater adjusting tank, a pH adjusting tank, a pre-settling tank and an intermediate water tank;

the desalination system comprises: the device comprises a multi-medium filter, an ultrafilter, an ultrafiltration water tank, a nanofiltration water tank, a reverse osmosis device and a reverse osmosis water tank.

The ultra-filtration device is characterized in that a polyether sulfone ultrafiltration membrane is used as the ultra-filtration device, a polyether sulfone nanofiltration membrane is used as the nanofiltration device, and a polyether sulfone reverse osmosis membrane is arranged in the reverse osmosis device.

In another aspect, the present application provides a method for using a nickel-containing wastewater treatment system, comprising the steps of:

s1, pretreatment: allowing the nickel-containing wastewater to enter a pH adjusting tank, adding alkali to adjust the pH to be 5.0-5.5, coagulating and precipitating with Jining in a preliminary sedimentation tank, conveying the supernatant to an intermediate water tank, and performing further sedimentation in the intermediate water tank to obtain an intermediate solution;

s2, desalting treatment: and (3) conveying the intermediate liquid to a multi-medium filter, sequentially carrying out ultrafiltration, nanofiltration and reverse osmosis to obtain filtrate, conveying the filtrate to an ultrafiltration water tank again, carrying out nanofiltration and reverse osmosis again, and outputting to a reverse osmosis water tank to obtain treated wastewater.

Examples 2 to 4

The difference from example 1 is that: using ultrafiltration membranes 1 to 3 in place of the ultrafiltration membrane of example 1, treated wastewater 2 to 4 was obtained.

Examples 5 to 12

The difference from example 1 is that: and (3) adopting a nanofiltration membrane 1-8 to replace the nanofiltration membrane in the embodiment 1 to obtain treated wastewater 5-12.

Example 13

The difference from example 1 is that: the reverse osmosis membrane in preparation 13 was used in place of the reverse osmosis membrane in example 1 to obtain treated wastewater 13.

Example 14

The difference from example 1 is that: the nickel-containing wastewater treatment system also comprises an adsorption treatment system, wherein an adsorbent is filled in the adsorption tank, and the adsorbent is sepiolite and steel slag. And (4) conveying the wastewater in the reverse osmosis pool to the adsorption pool for re-adsorption, and outputting supernatant to obtain treated wastewater 14.

Among them, it is worth mentioning: the adsorbent is selected from any one or two of sepiolite, steel slag and ionic resin, and the sepiolite and the steel slag are selected in the application.

Example 15

The difference from example 14 is that: the treated wastewater 15 was obtained by using the same-mass magnetically-modified sepiolite as an adsorbent in place of the sepiolite in example 15.

Example 16

The difference from example 15 is that: the treated wastewater 16 was obtained by using the same mass of the modified steel slag as an adsorbent in place of the steel slag used in example 14.

Comparative example

Comparative example 1

This comparative example differs from example 1 in that it includes only a pretreatment system, resulting in treated wastewater 17.

Comparative example 2

This comparative example differs from example 1 in that only an ultrafilter is included in the desalination system in this comparative example, resulting in treated wastewater 18.

Performance test

(1) And (3) detecting the nickel content of the wastewater: detecting the nickel content in the wastewater before and after treatment according to GB/T11910-1989-detection of nickel in water by dimethylglyoxime spectrophotometry, recording the absorbance and concentration of the solution to be detected at the wavelength of 530nm, and calculating the recovery rate of nickel, wherein the initial concentration of total nickel in the wastewater is 1000mg/L;

(2) And (3) pH value detection: detecting the pH values of the wastewater and the treated wastewater by a pH detector, wherein the average pH value of the wastewater is 2;

(3) And (3) COD detection: and (3) detecting the COD value of the wastewater and the treated wastewater by using a COD detector, wherein the COD value of the wastewater is 500mg/L.

(4) And (3) anti-pollution detection: HA was selected as the representative of the contaminants and used for the anti-contamination performance test. HA was present at a concentration of 0.2g/L as a contaminant. The anti-fouling performance of the membrane was evaluated by the Flux Recovery Rate (FRR), total flux decay rate (DRt), reversible flux decay rate (DRr) and irreversible flux decay rate (DRir), with the test temperature maintained at 25 ℃. The specific process is as follows:

pre-pressing: prepressing the membrane at 0.5MPa to ensure that the water flux of the membrane is in a stable state;

and (3) testing pure water flux: measuring the mass of the percolate of the membrane within a certain time under the pressure of 0.4MPa, and obtaining the pure water flux by using a flux calculation formula;

testing the flux of pollutants: replacing pure water with the pollutant solution, measuring the mass of the percolate of the membrane within a certain time under the pressure of 0.4MPa, and calculating to obtain the flux of the pollutant solution;

cleaning: washing the polluted membrane with deionized water for 30min;

testing pure water flux of the membrane after cleaning: and measuring the quality of the exudate of the cleaned membrane under the pressure of 0.4MPa, and calculating to obtain the pure water flux of the cleaned membrane. Flux recovery = pure water flux/pure water flux of the membrane after washing × 100%.

TABLE 3 Performance test of examples 1 to 16 and comparative examples 1 to 2

The pH after treatment in examples 1-16 was 5.5.

The nanofiltration membranes, the ultrafiltration membranes and the reverse osmosis membranes in the embodiments 2 to 13 are subjected to an anti-HA pollution test, and the flux recovery rates of the nanofiltration membranes, the ultrafiltration membranes and the reverse osmosis membranes are detected to be more than 75.96%. That is to say, the adhesiveness of the pollutants on the nanofiltration membrane, the ultrafiltration membrane and the reverse osmosis membrane is poor, the cleaning times of the nanofiltration membrane, the ultrafiltration membrane and the reverse osmosis membrane are reduced, the cost is further saved, and the purification and recovery effects of the wastewater are improved.

The comparison of the performance tests in combination with table 3 can find that:

(1) In combination with example 1 and comparative examples 1-2, it can be found that: in the embodiment 1, the nickel content, the recovery rate and the COD content of the treated wastewater are all improved, and the pH value is relatively proper, which shows that the treatment of the wastewater by a physicochemical-membrane method can maintain high recovery rate and obtain higher desalination rate, and the arrangement of a reverse osmosis system can still ensure that the effluent quality is relatively good under the condition of relatively large fluctuation of incoming water, the number of wastewater treatment units is small, the generation of sludge is reduced, the whole process can be automatically controlled, and the treatment cost is effectively reduced.

(2) A comparison of example 1 with examples 2 to 4 shows that: in the embodiments 2 to 4, the nickel content, the recovery rate, and the COD content of the treated wastewater are all improved, and the pH value is also suitable, which indicates that the polyvinyl alcohol and the carbon nanotubes are combined by group crosslinking to form an interwoven layer having a plurality of pore structures, thereby reducing the interaction between the ultrafiltration membrane and the contaminants, increasing the polar force rejection effect between the ultrafiltration membrane and the contaminants, and imparting suitable hydrophilicity to the ultrafiltration membrane, thereby improving the anti-pollution effect of the ultrafiltration membrane.

(3) A comparison of example 1 with examples 5 to 9 shows that: in the examples 5 to 9, the nickel content, the recovery rate and the COD content of the treated wastewater were all improved, and the pH value was also suitable, which indicates that the permeability and the nao-nan effect of the nanofiltration membrane were improved by the use of the combination of arginine and piperazine, and therefore the rejection rate of the nanofiltration membrane for sulfate radicals was effectively improved. The addition amounts of arginine and piperazine are optimized, so that the compact, complete and defect-free nanofiltration membrane can be maintained, the hydrophilic effect of the nanofiltration membrane can be enhanced, the osmotic resistance of water is reduced, and the filtering effect of the nanofiltration membrane on wastewater is improved.

(4) A comparison of example 1 with examples 10 to 12 shows that: the nickel content, the recovery rate and the COD content of the wastewater treated in the embodiment 1 are all improved, and the pH value is relatively proper, which shows that the application introduces the zwitterionic polymer into the nanofiltration membrane through the interfacial polymerization reaction, improves the water throughput of the nanofiltration membrane, enables the nanofiltration membrane to be electronegative, and improves the rejection rate of the nanofiltration membrane to sulfate radicals.

(5) A comparison of example 1 with example 13 shows that: in example 13, the nickel content, the recovery rate, and the COD content of the treated wastewater were all improved, and the pH value was also suitable, which indicates that the application introduces silver nanoparticles into the middle layer of the reverse osmosis membrane by the reducibility of tannic acid, reduces the roughness of the surface of the reverse osmosis membrane, makes the surface approach to neutral, and reduces the possibility of the adhesion of contaminants on the reverse osmosis membrane by steric effect and energy barrier. And the sterilization effect of the reverse osmosis membrane is improved through the sterilization effect of the silver particles.

(6) A comparison of example 1 and comparative examples 14 to 16 shows that: the nickel content, the recovery rate and the COD content of the wastewater treated in the examples 14 to 16 are improved, and the pH value is relatively proper, which shows that the application can adsorb a small amount of nickel ions in reverse osmosis treatment through the pore structures, the high specific surface areas and the high adsorptivity of the sepiolite and the steel slag, further reduce the nickel ion content in the effluent, and effectively reduce the treatment cost by adopting the waste for secondary treatment.

The specific embodiments are only for explaining the present application and are not limiting to the present application, and those skilled in the art can make modifications to the embodiments without inventive contribution as required after reading the present specification, but all the embodiments are protected by patent law within the scope of the claims of the present application.

Claims (10)

1. The utility model provides a nickel-containing wastewater treatment system which characterized in that:

comprises a pretreatment system and a desalting system;

the pretreatment system comprises: a nickel-containing wastewater adjusting tank, a pH adjusting tank, a pre-settling tank and an intermediate water tank;

the desalination system comprises: the device comprises a multi-medium filter, an ultrafilter, an ultrafiltration pool, a nanofiltration pool, a reverse osmosis device and a reverse osmosis pool.

2. The nickel-containing wastewater treatment system according to claim 1, characterized in that: the ultrafilter comprises an ultrafiltration membrane, and the ultrafiltration membrane is a membrane with carbon nano tubes loaded on the surface.

3. The nickel-containing wastewater treatment system according to claim 2, wherein the preparation method of the ultrafiltration membrane comprises the following steps: and (2) taking the graphene dispersion liquid and the PVA dispersion liquid according to the mass ratio of 1.

4. The nickel-containing wastewater treatment system according to claim 1, characterized in that: the nanofiltration device comprises a nanofiltration membrane, the nanofiltration membrane is an anti-pollution nanofiltration membrane, and the preparation of the anti-pollution nanofiltration membrane comprises the following steps: dipping the ultrafiltration membrane into the water phase solution, taking out, dipping the ultrafiltration membrane into the oil phase, carrying out heat treatment in an oven, taking out, and soaking in the reverse osmosis water solution to obtain the anti-pollution nanofiltration membrane; wherein the water phase comprises the following substances in parts by weight: 0.01-0.03 parts of reaction monomers of 60-80% of l-arginine and 20-40% of piperazine, 0.03 parts of triethylamine and 1 part of water; the oil phase comprises TMC-n-hexane with the mass concentration of 0.001-0.002 g/mL.

5. The nickel-containing wastewater treatment system according to claim 4, characterized in that: the water phase comprises the following substances in parts by weight: 0.01-0.03 part of reaction monomer, 0.0015 part of catalyst A and 1 part of water, wherein the reaction monomer comprises ethyl 2- (2-bromoisobutyloxy) acrylate, sulfobetaine, polydisiloxane, a complexing agent and a catalyst B.

6. The nickel-containing wastewater treatment system according to claim 1, characterized in that: the reverse osmosis device comprises a reverse osmosis membrane which is a silver-carrying reverse osmosis membrane treated by tannic acid.

7. The nickel-containing wastewater treatment system according to claim 1, characterized in that: the adsorption treatment system comprises an adsorption tank, wherein an adsorbent is filled in the adsorption tank, and the adsorbent is selected from any one or two of sepiolite, steel slag and ion resin.

8. The nickel-containing wastewater treatment system according to claim 7, wherein the sepiolite is a magnetically modified sepiolite, and the preparation of the sepiolite comprises the following steps: putting the sepiolite into the modification liquid, stirring and mixing, aging, cleaning, performing magnetic separation to realize solid-liquid separation, and drying to obtain the modified sepiolite; the modifying liquid comprises ferrous sulfate tetrahydrate and ferric chloride hexahydrate.

9. The nickel-containing wastewater treatment system according to claim 7, characterized in that: the steel slag is pretreated steel slag, and the pretreatment comprises the following steps: crushing the steel slag to ensure that the particle size of the steel slag is less than 5mm, dissolving the steel slag and the scrap iron in dilute hydrochloric acid and dilute nitric acid, stirring for reaction, and aging to obtain the pretreated steel slag.

10. Use of a nickel containing wastewater treatment system according to any of claims 1 to 9, characterized in that it comprises the following steps:

s1, pretreatment: allowing the nickel-containing wastewater to enter a pH adjusting tank, adding alkali for adjustment, performing coagulative precipitation by using Jining in a preliminary sedimentation tank, conveying the supernatant to an intermediate water tank, and performing further sedimentation in the intermediate water tank to obtain an intermediate solution;

s2, desalting treatment: and (3) conveying the intermediate liquid to a multi-medium filter, sequentially carrying out ultrafiltration, nanofiltration and reverse osmosis to obtain filtrate, conveying the filtrate to an ultrafiltration water tank again, carrying out nanofiltration and reverse osmosis again, and outputting to a reverse osmosis water tank to obtain treated wastewater.

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