A kind of functional cross-links chitosan-metal ion adsorbent
Technical field
The present invention relates to a kind of metal ion adsorbent, particularly a kind of functional cross-links chitosan-metal ionic adsorption
Agent belongs to environmental protection and materials science field.
Background technology
The production processes such as chemical industry, metallurgy, oil will generate a large amount of waste water, copper, cadmium, mercury, lead, palladium, rhodium in waste water,
Environmental problem caused by the metal ions such as platinum, iron, manganese has seriously jeopardized the sustainable development of social economy and common people's body is good for
Health, Processing Technology Research receive the extensive concern of domestic and foreign scholars.The method for removing metal ion at present mainly has precipitation
Method, ion exchange and absorption method.The precipitation method it is less efficient, and other impurity will be introduced while precipitate metal ion;
The selectivity of ion-exchange is poor and exchange capacity is relatively low;Sorbing material used in absorption method is usually cheap and easy to get, does not need to
The features such as complex appts and addition additional chemical substance.From the perspective of Technological Economy, absorption method becomes most common at present
One of contaminant metal ions processing method, and the research and development of wherein sorbing material are key technologies.Therefore, seek various tools
There are special or excellent properties as having special selectivity, high recycling rate, of low cost, preparation process simple and removal efficiency
High adsorbent is one of most noticeable research heat in the field.
Chitosan is the important derivatives of natural class polysaccharide chitin, is that reserves are only second to the most rich of cellulose in nature
Rich natural macromolecular material containing modifiable groups such as a large amount of hydroxyl and amino on strand, is easy to pass through modification
Various functions derivative is obtained, expands its application range.In addition, chitosan has transition metal ions good absorption to make
With available for removing the toxic metal ions in various waste water.However, chitosan is dissolved in a variety of acid mediums and is dropped
Solution is easily lost in, is not easily recycled, this causes the application of chitosan to bring significant limitation.Therefore, people often use dissimilarity
The crosslinking agent of matter is crosslinked chitosan to obtain the cross-linked chitosan stablized insoluble in diluted acid, property of reticular structure to meet
Difference needs.Since traditional cross-linking reaction often requires to use a large amount of organic solvents, preparation process is made to generate large amount of sewage, and
The shortcomings of cross-linked chitosan is also small there are particle, and sinking speed is slow significantly limits being widely used for such adsorbent.
For the present invention using crosslinking agent of the terephthalaldehyde as chitosan, organosilane reagents are functional groups presoma
Functional cross-links metal ion adsorbent is prepared, preparation process is simple, and raw material is cheap and easy to get, can directly be soaked in containing gold
Belong to adsorbing metal ions in the solution of ion, with adsorption rate is fast, the total class of metal ion of absorption is various, saturated extent of adsorption
The advantages that high, absorption property is stablized.The method is not yet reported.
Invention content
For existing chitosan-based metal ion adsorbent there are the problem of, the present invention provides a kind of letter of preparation process
List, good adsorption performance, cheap, environmental-friendly, functional cross-links metal ion adsorbent easy to use.
Functional cross-links metal ion adsorbent of the present invention through the following steps that complete:
(a) 1~3g of chitosan is added in the acetic acid solution of 2wt% (100ml), stirs 1h, by terephthalaldehyde and Asia
Niter cake is according to molar ratio 2:1 is configured to the aqueous solution of 2wt%, and the mixed solution of terephthalaldehyde and sodium hydrogensulfite is dripped
Be added in the acetic acid solution of chitosan (mass ratio of chitosan and terephthalaldehyde be 5:1~2:1) 30min, is stirred at room temperature, makes
Gel is obtained, after freeze-drying, white powder is ground to obtain, is cleaned with a large amount of water, 12h is dried in vacuo at 80 DEG C, crosslinking shell is obtained and gathers
Sugar.
(b) it is 3 according to mass ratio by above-mentioned gained cross-linked chitosan and organosilane reagents:1~1:2 it is added to 30~
It in 50mL toluene, flows back for 24 hours at 110 DEG C, centrifuges out solid powder, washed three times with toluene, 50 DEG C of vacuum drying 12h,
Obtain functional cross-links chitosan-metal ion adsorbent.
Above-mentioned functional cross-links chitosan-metal ion adsorbent, it is characterised in that the deacetylation of chitosan for 95~
98%;Organosilane reagents are 3- mercaptopropyltriethoxysilanes, 3- aminopropyl triethoxysilanes and 2- cyano in step (b)
One kind in ethyl triethoxysilane;Functional cross-links chitosan-metal ion adsorbent has high suction to metal ion
Attached ability, can be widely used for chemical industry, metallurgy and petroleum industry it is wastewater produced in copper, cadmium, mercury, lead, palladium, rhodium, platinum, iron, manganese
Absorption with detaching.
Advantages of the present invention and effect:
1st, Functional chitosan metal absorbent preparation process of the invention is simple, and reaction condition is mild, improves shell and gathers
The shortcomings of the acid-soluble of saccharide matrix, matter is soft, difficult separation.
2nd, Functional chitosan metal absorbent adsorption capacity produced by the present invention is strong, and adsorption rate is fast, the metal of absorption
The advantages that total class of ion is various, saturated extent of adsorption is high.
3rd, it is easy to operate when Functional chitosan metal absorbent produced by the present invention uses, it can be fast by centrifuging or filtering
Speed separation.
Description of the drawings
The synthetic route schematic diagram of Functional chitosan metal absorbent prepared by Fig. 1 present invention.
Scanning electron microscope (SEM) figure of Functional chitosan metal absorbent prepared by Fig. 2 present invention.
Specific embodiment
The present invention is further illustrated below by specific embodiment, but does not limit the present invention.
【Embodiment 1】
Chitosan 1g is added in the acetic acid solution (100ml) of 2wt%, 1h is stirred, by terephthalaldehyde and bisulfite
Sodium is according to molar ratio 2:1 is configured to the aqueous solution of 2wt%, and the mixed solution of terephthalaldehyde and sodium hydrogensulfite is added drop-wise to shell
(mass ratio of chitosan and terephthalaldehyde is 4 in the acetic acid solution of glycan:1) 30min, is stirred at room temperature, gel, freezing is made
After drying, white powder is ground to obtain, is cleaned with a large amount of water, 12h is dried in vacuo at 80 DEG C, obtains cross-linked chitosan.
According to mass ratio it is 1 by above-mentioned gained cross-linked chitosan and 3- mercaptopropyltriethoxysilanes:1 is added to 30mL first
It in benzene, flows back for 24 hours at 110 DEG C, centrifuges out solid powder, washed three times with toluene, 50 DEG C of vacuum drying 12h obtain mercapto
Base functional cross-links chitosan-metal ion adsorbent.
Synthetic route schematic diagram is shown in Fig. 1.
【Embodiment 2】
Operating method only changes organosilane reagents 3- mercaptopropyltriethoxysilanes into 3- aminopropyls with embodiment 1
Triethoxysilane obtains amino functional cross-linked chitosan metal ion adsorbent.
【Embodiment 3】
Operating method only changes organosilane reagents 3- mercaptopropyltriethoxysilanes into 2- cyano second with embodiment 1
Ethyl triethoxy silicane alkane obtains cyano ethyl functional cross-links chitosan-metal ion adsorbent.
Application Example 1
Configuration is containing copper (II) deionized water solution 100mL, a concentration of 25mg/L, with thiol functionality cross-linked chitosan gold
Belong to ion adsorbent (0.02g) 25 DEG C concussion absorption 1h after, filter out adsorbent, after absorption in solution copper (II) ion it is dense
It spends for 0.02mg/L, adsorption rate 99.92%.
Application Example 2
Configuration containing palladium (II) deionized water solution 100mL, wherein, dimethylformamide concentration 25% (V/V), palladium (II) from
A concentration of 50mg/L of son, with thiol functionality cross-linked chitosan metal ion adsorbent (0.02g) after 25 DEG C of concussion absorption 1h,
Filter out adsorbent, after absorption in solution palladium (II) ion a concentration of 0.1mg/L, adsorption rate 99.8%.