CN112295547A

CN112295547A - Preparation method of fly ash/carboxymethyl cellulose/chitosan composite material

Info

Publication number: CN112295547A
Application number: CN202011023524.4A
Authority: CN
Inventors: 李贞玉; 刘涛; 范伊焘; 陈妍; 苏佳杭; 闫钰
Original assignee: Changchun University of Technology
Current assignee: Changchun University of Technology
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2021-02-02

Abstract

The invention relates to a preparation method of a fly ash/carboxymethyl cellulose/chitosan composite material, belonging to the field of adsorption materials. At present, most of commonly used phosphorus removal adsorbents are powder and small particles, and have the problems of high cost, difficult recovery and the like, so that a novel adsorbent needs to be developed. The invention relates to a composite gel bead prepared by using industrial waste fly ash, carboxymethyl cellulose and chitosan which have good gelling property and no pollution and by using the principle that the carboxymethyl cellulose can be rapidly gelled in a solution containing high-valence metal ions. The preparation process is simple, the raw materials are cheap and easy to obtain, the preparation period is short, and the prepared material has stable mechanical properties. The adsorbent prepared by the invention can adsorb and remove phosphorus in sewage at room temperature, and has good application prospect.

Description

Preparation method of fly ash/carboxymethyl cellulose/chitosan composite material

Technical Field

The invention belongs to the technical field of adsorbent materials, and particularly relates to a preparation method and application of a fly ash/carboxymethyl cellulose/chitosan composite material.

Background

In recent decades, with the rapid development of industrial and agricultural technologies in China, the problems of air pollution, soil pollution and water pollution become increasingly serious. Among them, eutrophication of water body has become the most serious environmental problem at present, which is caused by unbalanced input and output of nutrient substances such as nitrogen and phosphorus, which are key factors directly influencing the growth of algae and plankton. When the algae and plankton in the water absorb the phosphorus nutrient elements, the algae and plankton can be rapidly propagated in a large area, and consume the dissolved oxygen in the water, so that the content of the dissolved oxygen is reduced, and the dissolved oxygen cannot be sufficiently provided for other organisms in the water, such as plants, fishes and other aquatic animals, so that the aquatic animals are difficult to breathe, and further the aquatic animals die in large batches. The prevention and the solution of eutrophication of water bodies are the most critical problems for treating water pollution at present.

Recently, researchers have conducted extensive research and study on the problem of effectively degrading excessive phosphorus in water, and have endeavored to find an efficient method for degrading phosphorus. The most difficult problem at present is to find a technology for removing phosphorus, which is efficient, low in cost and free from secondary pollution. The phosphorus removal method mainly comprises an adsorption method, a chemical precipitation method, a biological method, a membrane separation method and the like. The adsorption method has the advantages of simplicity and convenience in operation, low cost, no secondary pollution, small occupied area, stable effect and the like in the dephosphorization process, and has the greatest characteristic of effectively recycling phosphorus resources through the adsorption-desorption process, so that the adsorption method is widely used in the dephosphorization industry. Common adsorbents are activated carbon, zeolite, and the like.

The fly ash is fine ash collected from flue gas generated after coal combustion, and is main solid waste discharged from a coal-fired power plant. The fly ash can be recycled, and can be used as an admixture of concrete and the like. Because the particles are in a porous honeycomb structure, the specific surface area is large, the adsorption activity is high, and the porosity is as high as 50% -80%, the particles are further used as an adsorbent to remove phosphorus in a water body. But the phosphorus removal agent is directly put into water body for adsorption and phosphorus removal, and is difficult to recover, if the phosphorus removal agent is not recovered in time, river siltation can be caused, so the phosphorus removal agent is made into a spherical shape so as to be convenient for timely recovery. Carboxymethyl cellulose (CMC) isThe natural anionic water-soluble polysaccharide is low in price because it contains Fe^{3 +}Or Al^{3 +}Form spherical gel beads and are therefore widely used for the preparation of adsorbents for use in sewage treatment processes. Chitosan (CS) has attracted considerable attention in various fields because of its characteristics such as non-toxicity, safety, and degradability, and has been studied in many fields such as water pollutant treatment.

Disclosure of Invention

The invention aims at the defects of the prior art and provides a preparation method of a fly ash/carboxymethyl cellulose/chitosan composite material. The method is simple to operate, safe, environment-friendly and low in cost. Can effectively adsorb phosphorus in the wastewater at room temperature, has good stability after adsorption, and can recover phosphorus through desorption treatment.

The technical scheme adopted by the invention comprises the following steps:

1) dissolving a certain amount of carboxymethyl cellulose in water, and stirring for 1-2h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a CMC solution with a certain concentration;

2) adding a certain amount of fly ash into the solution, and stirring for 1-2h until the mixture is uniform to obtain a CMC/fly ash mixed solution;

3) dissolving a certain amount of aluminum chloride in 60ml of water to obtain an aluminum chloride solution with a certain concentration;

4) dripping the CMC/fly ash mixed solution into the aluminum chloride solution in the step 3) by using an injector, and slightly stirring to stabilize the mixture for 1 to 3 hours;

5) preparing a chitosan solution with a certain concentration, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking for 2-4 hours;

6) washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ overnight to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Preferably, 1g of carboxymethyl cellulose is dissolved in 20ml of water in step 1);

preferably, the adding amount of the fly ash in the step 2) is 3 g;

preferably, the weight ratio of the CMC/fly ash mixed solution is CMC: fly ash =1: 3;

preferably, the concentration of the aluminum chloride solution in the step 3) is 5%;

preferably, the concentration of the chitosan solution is 1%.

Detailed Description

Example 1:

dissolving 1g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 5% CMC solution; adding 3g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 3g of aluminum chloride is dissolved in 60ml of water to obtain a 5% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 2:

dissolving 0.8g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 4% CMC solution; adding 2.4g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 3g of aluminum chloride is dissolved in 60ml of water to obtain a 5% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 3:

dissolving 0.6g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 3% CMC solution; adding 1.8g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 3g of aluminum chloride is dissolved in 60ml of water to obtain a 5% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 4:

dissolving 1g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 5% CMC solution; adding 3g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 2.4g of aluminum chloride is dissolved in 60ml of water to obtain a 4% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 5:

dissolving 1g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 5% CMC solution; adding 3g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; dissolving 1.8g of aluminum chloride in 60ml of water to obtain a 3% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 6:

dissolving 1g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 5% CMC solution; adding 3g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 3g of aluminum chloride is dissolved in 60ml of water to obtain a 5% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 2%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Example 7:

dissolving 1g of carboxymethyl cellulose in 20ml of water, and stirring for 1h at 60 ℃ until the carboxymethyl cellulose is completely dissolved to obtain a 5% CMC solution; adding 3g of fly ash into the solution, and stirring for 1 hour until the mixture is uniform to obtain a CMC/fly ash mixed solution; 3g of aluminum chloride is dissolved in 60ml of water to obtain a 5% aluminum chloride solution; dripping the CMC/fly ash mixed solution into the aluminum chloride solution obtained in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1 hour; preparing a chitosan solution with the concentration of 3%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking the gel beads for 2 hours; washing the gel beads with distilled water and ethanol, and drying in a vacuum drying oven at 40 ℃ for 12h to finally obtain the fly ash/carboxymethyl cellulose/chitosan composite adsorbing material.

Claims

1. A preparation method of a fly ash/carboxymethyl cellulose/chitosan composite material comprises the following steps:

4) dripping the CMC/fly ash mixed solution into the aluminum chloride solution in the step 3) by using a 20ml injector, and slightly stirring to stabilize the mixture for 1-3 h;

5) preparing a chitosan solution with the concentration of 1%, washing the gel beads obtained in the step 4), pouring the gel beads into the solution, and soaking for 2-4 hours;

2. The method for preparing the fly ash/carboxymethyl cellulose/chitosan composite material according to claim 1, wherein the method comprises the following steps: the mass ratio of the CMC/fly ash mixed solution is CMC: fly ash =1: 3.

3. The composite material according to claim 1, wherein the phosphorus in the wastewater can be removed by adsorption at normal temperature.