CN106861663A - A kind of micro-fluidic synthesis trace adsorbent for copper-containing wastewater treatment - Google Patents

Abstract

The invention relates to a microfluidic synthetic imprinted adsorbent for the treatment of copper-containing wastewater, which is prepared by the following method: dissolving soluble copper salt and acetic acid in chitosan solution, and the concentration of copper ions, chitosan and acetic acid The mass ratio is 1:(1~5):(1~4), heated and stirred to obtain the dispersed phase; then the continuous phase is cut into the dispersed phase with a microfluidic device, and the formed micro-droplets are introduced into the solidified liquid Cross-linking and curing; finally, the cured micro-droplets are desorbed with a desorbent, washed and dried to obtain the required adsorbent. The invention is simple in operation and low in cost, and the obtained adsorbent has specific selective adsorption performance for copper ions, fast adsorption speed, high adsorption capacity, and can be reused; using microfluidic granulation technology, the particle size is uniform and the composition , uniform in shape and size, and has far-reaching research prospects for the treatment of industrial wastewater containing copper ions.

Description

A Microfluidic Synthetic Imprinted Adsorbent for Copper-Containing Wastewater Treatment

technical field

The invention relates to a microfluidic synthetic imprinted adsorbent for treating copper-containing wastewater, which belongs to the technical field of polymer composite materials.

Background technique

In recent years, with the development of modern industry, heavy metal pollution in wastewater has become one of the most serious environmental problems. Wastewater containing heavy metals can directly or indirectly cause permanent poisoning of humans and livestock. Copper can affect human hematopoiesis, cell growth, activities of certain human enzymes, and endocrine gland functions. Excessive intake of copper will stimulate Digestive system, causing abdominal pain, vomiting, and even death. Adsorption technology plays an irreplaceable role in the field of water pollution control and water purification. Adsorption material refers to a polymer material that has a specific molecule or ion and thus has a selective affinity. This type of material generally has a large pore size and specific surface area, and can effectively adsorb some components from gases or liquids. It is a solid substance with the characteristics of convenient manufacture, easy regeneration, and high mechanical strength. However, traditional adsorption materials are difficult to biodegrade, and often cause environmental pollution after use and disposal. Natural polymers such as cellulose and chitosan have a variety of functional groups, are economically available, and have good biocompatibility and biodegradability. Therefore, they have become important raw materials for the preparation of adsorption resins.

The traditional methods for preparing chitosan microspheres include emulsification‐crosslinking method, reverse suspension method, single coacervation method, etc. Most of these methods have microsphere size inhomogeneity, uncontrollable, low preparation efficiency, poor repeatability, etc. characteristics, while the size and monodispersity of chitosan microspheres are critical for its adsorption applications. Therefore, the application of microfluidic equipment to achieve precise control of the number and size of microspheres, to prepare adsorbents with uniform particle size and high monodispersity, and to achieve efficient adsorption performance. In order to further improve the efficiency and reliability of the adsorption process, which is also the industrial demand for efficient and specific selective adsorption of copper ions, we have adopted ion imprinting technology.

Ion imprinting technology refers to the preparation technology to obtain a polymer that completely matches an ion in space and binding sites, and this polymer is called an ion imprinted polymer. Ion-imprinted polymers have many cavities with fixed shapes and sizes, and the cavities usually have functional groups in a definite arrangement, which have a memory function for the three-dimensional structure of imprinted ions.

Therefore, the chitosan adsorbent prepared by microfluidic and ion imprinting technology has selective adsorption for copper ions, high adsorption efficiency, large adsorption solution, simple operation and low cost.

Contents of the invention

In order to improve the adsorption efficiency of industrial wastewater containing copper ions and meet the demand for specific selective adsorption of copper ions, the present invention develops a microfluidic synthetic imprinted adsorbent for copper-containing wastewater treatment, and the method for making the adsorbent is operated The method is simple, and the obtained adsorbent has high adsorption efficiency and selective adsorption for copper ions.

The present invention refers to realize by following technical scheme:

A microfluidic synthetic imprinted adsorbent for copper-containing wastewater treatment, characterized in that the adsorbent is prepared by the following method:

1) Dissolve soluble copper salt and acetic acid in chitosan solution, and heat and stir to obtain dispersed phase, the mass ratio of copper ion, chitosan and acetic acid is 1: (1～5): (1～4) ,

2) Shearing the dispersed phase obtained in step 1) with a continuous phase through a microfluidic device, and introducing the formed micro-droplets into a beaker containing a solidification solution for cross-linking and solidification,

3) Desorbing the solidified micro-droplets with a desorbent, washing and drying to obtain a microfluidic synthetic imprinted adsorbent for copper-containing wastewater treatment;

Wherein, the continuous phase is a mixed solution of Span and n-octane or Span and n-octanol, the mass fraction of Span in the continuous phase is 2% to 4%, and n-octane or n-octanol is the oil phase;

The curing liquid is a mixture of a continuous phase and a curing agent, wherein the mass fraction of the curing agent in the curing liquid is 0.5% to 2%, and the curing agent is one of glutaraldehyde, epichlorohydrin, and crown ether;

The soluble copper salt can be one of copper chloride, copper sulfate, copper nitrate, and copper acetate, and the copper ions provided by these copper salts are all positive divalent copper ions.

In the step 1), the heating temperature for preparing the dispersed phase is 50-80° C., and the heating time is 3-5 hours.

In the step 2), when the continuous phase is sheared by the microfluidic device to the dispersed phase, the flow rate ratio of the dispersed phase to the continuous phase is (5:65)˜(10:65).

In the step 2), the amount of solidified liquid contained in the beaker is 40-80 ml, and the solidified time is 0.5-3 hours.

In the step 3), the desorbing agent can be one of nitric acid, hydrochloric acid and ethylenediaminetetraacetic acid, and its concentration is 0.1-0.5mol/L.

In the step 3), the drying temperature is 30-50° C., and the drying time is 2-10 hours.

Advantages of the present invention:

The present invention prepares a microfluidic synthetic imprinted adsorbent for the treatment of copper-containing wastewater based on the microfluidic granulation technology and the application of ion imprinting technology. The adsorbent has selective adsorption for copper ions and high adsorption efficiency. Large, simple operation, low cost, and reusable performance; using microfluidic granulation technology, the particle size is uniform, the composition, shape and size are uniform, and it has far-reaching research on the treatment of industrial wastewater containing copper ions prospect.

Description of drawings

Fig. 1 is the schematic diagram of the preparation process of the copper ion imprinting adsorbent prepared by the present invention

detailed description

The present invention will be further elaborated below in conjunction with embodiment.

Example 1:

Sorbent preparation steps:

1) add 1.6 gram chitosan in the beaker of 100 milliliters, add 40 milliliters of deionized waters then, add the cupric chloride crystal of 0.3824 grams again, be placed on magnetic stirrer and stir, add 0.8 milliliters of glacial acetic acid while stirring, After fully dissolving, heat in a water bath at a constant temperature of 60°C for 3 hours to obtain a dispersed phase;

2) Add 3 grams of Span in a 250 ml beaker, then add 209 ml of n-octane, stir for 1 hour to obtain a continuous phase; add 3 grams of Span in a 250 ml beaker, then add 205 ml of n-octane , finally add 3 ml of glutaraldehyde, stir for 1 hour to obtain a water bath solidification solution; use a microfluidic device, with the flow rate ratio of the dispersed phase and the continuous phase being 5:65, shear the prepared dispersed phase with the continuous phase, and The formed droplet is introduced into a beaker containing 60 milliliters of water-bath curing solution, and the water-bath is solidified for 1 hour;

3) Wash the cured micro-droplets with ethanol solution and deionized water. Due to the addition of the copper salt required for ion imprinting, the cleaned microspheres are light green, and then use ethylenediaminetetraacetic acid desorbent for desorption. Attach for 15 minutes, wash and filter again, the desorbed microspheres turn light yellow, and it can be clearly seen that the color changes from light green to light yellow, which shows that the imprinted copper added to the previously prepared dispersed phase

The salt has been successfully desorbed, and finally dried at 40°C for 3 hours to obtain the desired adsorbent.

Its whole preparation process is shown in accompanying drawing 1, firstly is the chelation reaction of chitosan and copper ion, secondly is the cross-linking reaction of glutaraldehyde, finally is the desorption process of adsorbent.

The adsorbent prepared in Example 1 has remarkable adsorption capacity for copper ions, the adsorption equilibrium time is 76 hours, and the maximum adsorption capacity is 75 mg/g.

Example 2:

According to the preparation method of Example 1, the water bath solidification time was changed to 3 hours to obtain the required adsorbent. After absorbing copper ions, the adsorption equilibrium time was 85 hours and the maximum adsorption capacity was 60 mg/g.

Example 3:

According to the preparation method of Example 1, the amount of copper chloride crystals added was changed to 0.1 g to obtain the required adsorbent. After absorbing copper ions, the adsorption equilibrium time was 90 hours, and the maximum adsorption capacity was 68 mg/g. .

Claims (6)

1. it is a kind of for copper-containing wastewater treatment micro-fluidic synthesis trace adsorbent, it is characterised in that described adsorbent is logical Cross what following methods were prepared from：

1) by soluble mantoquita and acetic acid in chitosan solution, and heating stirring, obtain dispersed phase, copper ion, shell The mass ratio of glycan and acetic acid is 1: (1~5): (1~4),

2) step 1 is sheared with continuous phase as micro fluidic device) obtained by dispersed phase, and the microlayer model of formation be incorporated into be equipped with Crosslinking curing is carried out in the beaker of solidify liquid,

3) microlayer model being cured is desorbed using desorbing agent, and cleans, dries, that is, be obtained for copper-containing wastewater treatment Micro-fluidic synthesis trace adsorbent；

Wherein, continuous phase is Span and normal octane or the mixed solution of Span and n-octyl alcohol, quality of the Span in continuous phase point Number is 2%~4%, and normal octane or n-octyl alcohol are oil phase；

Solidify liquid is the mixture of continuous phase and curing agent, and the mass fraction of curing agent is 0.5%~2% wherein in solidify liquid, Described curing agent is the one kind in glutaraldehyde, epoxychloropropane, crown ether；

Soluble copper salt is the one kind in copper chloride, copper sulphate, copper nitrate, copper acetate.

2. it is as claimed in claim 1 to be used for the micro-fluidic synthesis trace adsorbent that copper-containing wastewater is processed, it is characterised in that described Step 1) in, the heating-up temperature for preparing dispersed phase is 50~80 DEG C, and the time is 3~5 hours.

3. it is as claimed in claim 1 to be used for the micro-fluidic synthesis trace adsorbent that copper-containing wastewater is processed, it is characterised in that described Step 2) in, when continuous phase being sheared into dispersed phase using micro fluidic device, its dispersed phase is (5 with the velocity ratio of continuous phase:65) ~(10:65).

4. it is as claimed in claim 1 to be used for the micro-fluidic synthesis trace adsorbent that copper-containing wastewater is processed, it is characterised in that described Step 2) in, the amount of the solidify liquid being equipped with beaker is 40~80 milliliters, and hardening time is 0.5~3 hour.

5. it is as claimed in claim 1 to be used for the micro-fluidic synthesis trace adsorbent that copper-containing wastewater is processed, it is characterised in that described Step 3) in, desorbing agent can be the one kind in nitric acid, hydrochloric acid, ethylenediamine tetra-acetic acid, and its concentration is 0.1~0.5mol/L.

6. it is as claimed in claim 1 to be used for the micro-fluidic synthesis trace adsorbent that copper-containing wastewater is processed, it is characterised in that described Step 3) in, drying temperature is 30~50 DEG C, and drying time is 2~10 hours.