阅读说明：本技术 用于去除重金属的吸附剂及其应用 (Adsorbent for removing heavy metals and application thereof ) 是由 魏旭榕 于 2019-08-23 设计创作，主要内容包括：本发明关于去除重金属离子领域,特别是关于一种用于去除重金属的吸附剂及其应用,包括：二硫代羧化聚丙烯酰胺、酵母菌表面活性剂、柠檬酸铁；以干物质计,所述吸附剂中的二硫代羧化聚丙烯酰胺、酵母菌表面活性剂与柠檬酸铁的质量比是100:1.5～2.0:5～10。所述吸附剂具有二硫代羧化聚丙烯酰胺吸附酵母菌表面活性剂和柠檬酸铁形成的三元结构,对流体中的重金属离子如Cd(Ⅱ)、Cu(Ⅱ)、Gr(Ⅵ)、Ni(Ⅱ)与As(Ⅴ)等的吸附去除率均可达95％以上,而且具有良好的再吸附性能,延长吸附剂的使用寿命。(The invention relates to the field of heavy metal ion removal, in particular to an adsorbent for removing heavy metal and application thereof, wherein the adsorbent comprises the following components: dithio-carboxylated polyacrylamide, yeast surfactant and ferric citrate; the mass ratio of the dithio-carboxylated polyacrylamide, the yeast surfactant and the ferric citrate in the adsorbent is 100: 1.5-2.0: 5-10 in terms of dry matter. The adsorbent has a ternary structure formed by absorbing yeast surfactants and ferric citrate by dithio-carboxylated polyacrylamide, has an adsorption removal rate of more than 95% for heavy metal ions in fluid such As Cd (II), Cu (II), Gr (VI), Ni (II), As (V) and the like, and has good re-adsorption performance, and the service life of the adsorbent is prolonged.)

1. An adsorbent for removing heavy metals, characterized by comprising:

-a dithiocarboxylated polyacrylamide;

-a yeast surfactant;

-ferric citrate;

wherein the mass ratio of the dithio-carboxylated polyacrylamide, the yeast surfactant and the ferric citrate in the adsorbent is 100: 1.5-2.0: 5-10 in terms of dry matter.

2. The sorbent of claim 1, wherein: the method for preparing the dithio-carboxylated polyacrylamide comprises the following steps:

1) adding a formaldehyde solution into a polyacrylamide solution under stirring, adjusting the pH of the system to be not less than 10.0 by using a NaOH solution, and reacting at 48-55 ℃ for 2h to obtain hydroxymethylated polyacrylamide;

2) adjusting the concentration of a hydroxymethylated polyacrylamide solution to 0.55-0.6 wt%, adding a NaOH solution, pre-reacting for 8-10 min, adding carbon disulfide, and carrying out a two-stage reaction to obtain the catalyst.

3. The sorbent of claim 2, wherein: in the step 1), the mass ratio of the polyacrylamide structural unit to the formaldehyde is 1: 1.0-1.5.

4. The sorbent of claim 2, wherein: in the two-stage reaction in the step 2),

the first-stage reaction temperature is 23-25 ℃, and the time is 45-60 min;

the reaction temperature of the second stage is 45-48 ℃ and the time is 70-90 min.

5. The sorbent of claim 1, wherein: the method for preparing the yeast surfactant comprises the following steps: preparing a fermentation medium: 8.0-10.0 g/L of ammonium sulfate, 1.2-1.5 g/L of potassium chloride, 1.5-2.5 g/L of sodium chloride, 4.5-6.5 g/L of monopotassium phosphate, 0.05-0.08 g/L of ferrous sulfate, 2.5-3.0 g/L of magnesium sulfate, 0.6-1.0 g/L of yeast extract, 15.0-18.0 mL/L of n-hexadecane, 0.25-0.3 g/L of ethanol, 0.26-0.28 mg/L of ebelanone, 5.0-10.0 mL/L of trace element liquid, the balance of distilled water, the initial pH value of 7.2-7.4, and high-pressure steam sterilization; inoculating and culturing 1.0-10.0% of yeast liquid in an ultra-clean workbench to the yeast liquid fermentation culture in the later logarithmic phase; adjusting pH of the fermentation liquid to 8.2 or above, centrifuging at high speed to remove thallus, and performing acid precipitation, chloroform-methanol extraction and purification, and vacuum freeze drying.

6. The adsorbent according to claim 1 or 5, characterized in that: the yeast is marine yarrowia lipolytica.

7. A method for producing the adsorbent according to any one of claims 1 to 6, characterized by comprising: dissolving ferric citrate in an ethanol water solution to obtain a ferric citrate mixed solution, slowly adding dithio-carboxylated polyacrylamide under stirring at room temperature, adjusting the pH to 7.8-8.5, slowly adding a yeast surfactant, heating to 38-45 ℃, slowly stirring and loading for 2-5 hours, aging and finishing subsequent treatment to obtain the ferric citrate mixed solution.

8. The method of claim 7, wherein: the mass ratio of the dithio-carboxylated polyacrylamide to the yeast surfactant to the ferric citrate is 100: 1.5-2.0: 5-10 in terms of dry matter.

9. The method of claim 7, wherein: and the subsequent treatment refers to filtering, washing and drying after aging to obtain the adsorbent.

10. Use of an adsorbent for the removal of heavy metals, characterized in that:

the application comprises removing heavy metal ions in the fluid;

the adsorbent is as defined in any one of claims 1 to 6 or is prepared by the process of any one of claims 7 to 9.

Technical Field

The invention relates to the field of heavy metal ion removal, in particular to an adsorbent for removing heavy metal and application thereof.

Background

With the rapid development of the industrial and mining industry and the aquaculture industry, a large amount of mine wastewater, heavy metal-containing industrial wastewater and aquaculture wastewater are discharged into surface water, and the heavy metal pollution degree of a drinking water source is increasingly serious. Heavy metals, as a class of non-degradable pollutants, persist in the environment and are enriched in organisms and human bodies through bio-amplification and food chain transfer effects, constituting a potential threat to human health and ecological balance. Heavy metal wastewater is wastewater with the characteristics of strong toxicity, carcinogenicity, mutagenicity, difficult degradation, easy enrichment and the like, has the characteristics of toxicity effect, long-term persistence, biodegradability and the like, heavy metal is dissolved in the wastewater or suspended in the wastewater, cannot be degraded by microorganisms, can only migrate and convert among water, substrate and organisms in different valence states to generate dispersion and enrichment effects, and the heavy metal in the water body accumulated to a certain limit can generate serious harm to the water body, aquatic plants and aquatic animal systems, so that organisms have vicious symptoms, physiological obstruction, growth retardation and even death, the structure and function of the whole aquatic ecosystem are damaged and collapsed, and simultaneously, the heavy metal can enter a human body through the action of food chains and be accumulated in the human body, thereby causing various diseases and functional disorders and finally causing serious harm to the health of the human body, with the development of industry, heavy metal pollution is also widely regarded.

The existing sewage treatment technologies can be divided into physical methods, chemical methods, physicochemical methods and biological methods according to the principle, wherein the physical methods are used for separating and recovering insoluble pollutants in a suspended state in the wastewater through physical action, and the gravity separation method, the centrifugal separation method, the filtration method and the like are commonly used. The chemical treatment method is to add certain chemical substances into the sewage, separate and recover the pollutants in the sewage by utilizing chemical reaction, and the chemical precipitation method, the coagulation method, the neutralization method, the oxidation-reduction method and the like are commonly used; the physical and chemical method is to remove pollutants in the wastewater by utilizing the physical and chemical action, and mainly comprises an adsorption method, an ion exchange method, a membrane separation method, an extraction method and the like; the biological treatment method is a method for converting organic pollutants in a solution, colloid and fine suspension state in wastewater into stable and harmless substances by the metabolism of microorganisms, and can be divided into an aerobic biological treatment method and an anaerobic biological treatment method. However, these methods have the disadvantages of unstable removal effect, single removal of heavy metal ions, easy generation of secondary pollution, high treatment cost, etc., so how to select a reasonable, effective and practical adsorbent for removing heavy metal ions is a problem generally faced at present.

The above background disclosure is only for the purpose of assisting understanding of the inventive concept and technical solutions of the present invention, and does not necessarily belong to the prior art of the present patent application, and should not be used for evaluating the novelty and inventive step of the present application in the case that there is no clear evidence that the above content is disclosed at the filing date of the present patent application.

Disclosure of Invention

The invention aims to provide an adsorbent for removing heavy metals and application thereof, wherein the adsorbent has a ternary structure formed by absorbing yeast surfactants and ferric citrate by dithio-carboxylated polyacrylamide, has adsorption removal rates of more than 95% for heavy metal ions in fluid such As Cd (II), Cu (II), Gr (VI), Ni (II), As (V) and the like, and has good re-adsorption performance and prolonged service life.

The technical solutions of the present invention for achieving the above objects include the following items [1] to [3 ].

[1] An adsorbent for removing heavy metals, comprising:

-a dithiocarboxylated polyacrylamide;

-a yeast surfactant;

-ferric citrate;

wherein the mass ratio of the dithio-carboxylated polyacrylamide, the yeast surfactant and the ferric citrate in the adsorbent is 100: 1.5-2.0: 5-10 in terms of dry matter.

This application an adsorbent for getting rid of heavy metal is dithio-carboxylation polyacrylamide/yeast surfactant/ferric citrate ternary structure, this adsorbent passes through modified polyacrylamide load yeast surfactant and ferric citrate, on the basis that improves resin adsorption capacity, give the synchronous adsorption of adsorbent and get rid of the characteristic of heavy metal ion such As Cd (II), Cu (II), Gr (VI), Ni (II) and As (V), and show good reabsorption performance to above-mentioned heavy metal ion, both solved the easy problem of agglomerating of hydroxyl iron and using the back difficult to separate, improve the ability that modified polyacrylamide resin adsorbs heavy metal ion again with the help of hydroxyl iron and yeast surfactant, and good reabsorption performance can improve the life of adsorbent.

In the present application, the method for preparing the dithiocarboxylated polyacrylamide comprises the following steps:

1) adding a formaldehyde solution into a polyacrylamide solution under stirring, adjusting the pH of the system to be not less than 10.0 by using a NaOH solution, and reacting at 48-55 ℃ for 2h to obtain hydroxymethylated polyacrylamide;

2) adjusting the concentration of a hydroxymethylated polyacrylamide solution to 0.55-0.6 wt%, adding a NaOH solution, pre-reacting for 8-10 min, adding carbon disulfide, and carrying out a two-stage reaction to obtain the catalyst.

In the summary of the invention and the preferred embodiment, the mass ratio of the polyacrylamide structural units to formaldehyde in step 1) is 1:1.0 to 1.5, preferably 1:1.0 to 1.2.

In the summary and the preferred embodiment of the present invention, the pH value of the reaction system in the step 1) is preferably 10.0 to 12.0, and more preferably 10.2 to 11.5.

In the invention and the preferred embodiment, the pre-reaction in the step 2) is carried out at 25-28 ℃ and 60-120 r/min.

In the invention, in a preferred embodiment, the mass ratio of hydroxymethylated polyacrylamide to carbon disulfide to sodium hydroxide in the step 2) is 1: 1.4-1.6: 2.0-2.5.

In the invention and the preferred embodiment, in the two-stage reaction in the step 2), the first stage reaction temperature is 23-25 ℃ and the time is 45-60 min; the reaction temperature of the second stage is 45-48 ℃ and the time is 70-90 min.

According to the method, polyacrylamide is used as a matrix, hydroxymethylation is carried out to prepare hydroxymethylated polyacrylamide in sequence, then strong ligand dithio carboxyl (-CSS-) of heavy metal ions is introduced into the hydroxymethylated polyacrylamide to prepare dithio carboxylated polyacrylamide, Cu (II) can be trapped through chelation, condensation and settlement of chelated precipitates can be accelerated through self-adsorption bridging, net trapping, rolling sweeping and other actions, and the Cu (II) in the wastewater can be effectively removed; in addition, the dithio-carboxylated polyacrylamide can be used As a body to load yeast surfactants and ferric citrate, so that the adsorbent is endowed with a ternary structure, the range and the performance of the adsorbent capable of adsorbing heavy metal ions are enhanced, and the adsorption removal effect on heavy metal ions in wastewater and sewage, such As Cd (II), Cu (II), Gr (VI), Ni (II), As (V) and the like, can reach more than 95%.

In the present application, the method for preparing the yeast surfactant comprises the following steps: preparing a fermentation medium: 8.0-10.0 g/L of ammonium sulfate, 1.2-1.5 g/L of potassium chloride, 1.5-2.5 g/L of sodium chloride, 4.5-6.5 g/L of monopotassium phosphate, 0.05-0.08 g/L of ferrous sulfate, 2.5-3.0 g/L of magnesium sulfate, 0.6-1.0 g/L of yeast extract, 15.0-18.0 mL/L of n-hexadecane, 0.25-0.3 g/L of ethanol, 0.26-0.28 mg/L of ebelanone, 5.0-10.0 mL/L of trace element liquid, the balance of distilled water, the initial pH value of 7.2-7.4, and high-pressure steam sterilization; inoculating and culturing 1.0-10.0% of yeast liquid in an ultra-clean workbench to the yeast liquid fermentation culture in the later logarithmic phase; adjusting pH of the fermentation liquid to 8.2 or above, centrifuging at high speed to remove thallus, and performing acid precipitation, chloroform-methanol extraction and purification, and vacuum freeze drying.

In the context of the present invention and in a preferred embodiment, the conditions of the autoclaving are 1.2bar at 121 ℃ for 20 min.

In the summary of the invention and in a preferred embodiment, the solution of trace elements is: 20.0g/L of zinc borate, 10.0g/L of manganese chloride, 25.0g/L of copper sulfate, 7.5g/L of ammonium molybdate, 0.1g/L of cobalt nitrate and the balance of distilled water, and filtering and sterilizing the mixture by using a filter membrane of 0.22 mu m.

In the context of the present invention and in preferred embodiments, the yeast is a marine yarrowia lipolytica yeast.

In the invention and the preferred embodiment, the fermentation culture is carried out for 72-108 h at 28-30 ℃ and 150-180 r/min by shaking fermentation.

In the invention and the preferred embodiment, the conditions of the high-speed centrifugation are 12000-15000 r/min and 30 min.

In the method, the fermentation culture is carried out on the marine yarrowia lipolytica in the middle and later stages to prepare the fermentation liquid, the lipopeptide surfactant component can be extracted, particularly, under the condition that ethanol and ebelamuch are added into the fermentation culture medium, the extraction rate of the lipopeptide surfactant component is obviously improved, the extraction rate of the dry matter surfactant can reach more than 600mg/L, and the extraction rate of the active component is obviously improved; more importantly, the adsorbent formed by compounding the marine yarrowia lipolytica surfactant, ferric citrate and dithio-carboxylated polyacrylamide has a relatively obvious adsorption and aggregation effect on heavy metal ions, the adsorption effect on heavy metal ions in wastewater and sewage, such As Cd (II), Cu (II), Gr (VI), Ni (II), As (V) and the like, is most obvious, and the adsorption removal rate of the adsorbent for removing heavy metals on the heavy metal ions can reach more than 95%.

[2] A method for producing the adsorbent of item [1], which comprises: dissolving ferric citrate in an ethanol water solution to obtain a ferric citrate mixed solution, slowly adding dithio-carboxylated polyacrylamide under stirring at room temperature, adjusting the pH to 7.8-8.5, slowly adding a yeast surfactant, heating to 38-45 ℃, slowly stirring and loading for 2-5 hours, aging and finishing subsequent treatment to obtain the ferric citrate mixed solution.

In the summary and the preferred embodiment of the invention, the concentration of the ferric citrate in the ferric citrate mixed solution is 0.05-0.06 mol/L.

In the invention content and the preferred embodiment, the mass ratio of the dithio-carboxylated polyacrylamide to the yeast surfactant to the ferric citrate is 100: 1.5-2.0: 5-10 on a dry matter basis.

In the invention and the preferred embodiment, the stirring speed is 60 to 120 r/min.

In the invention and the preferred embodiment, the slow stirring speed is 20 to 60 r/min.

In the invention, the aging is carried out at 55-60 ℃ for at least 24 h.

In the invention and the preferred embodiment, the subsequent treatment refers to filtering, washing and drying after aging is completed to obtain the adsorbent.

This application forms the adsorbent ternary structure who is used for getting rid of the heavy metal with dithio carboxylation polyacrylamide adsorption yeast surfactant and ferric citrate, on the basis that improves resin adsorption capacity, give the adsorbent synchronous adsorption get rid of heavy metal ion like Cd (II), Cu (II), Gr (VI), Ni (II) and As (V) the characteristic, and show good reabsorption performance to above-mentioned heavy metal ion, both solved the easy problem that is difficult to separate after reunion and the use of hydroxyl iron, improve the ability of modified polyacrylamide resin adsorption heavy metal ion with the help of hydroxyl iron and yeast surfactant again, and good reabsorption performance can improve the life of adsorbent.

[3] Use of an adsorbent for the removal of heavy metals, said use comprising the removal of heavy metal ions from a fluid.

In the summary of the invention and preferred embodiments, the adsorbent is the adsorbent according to any one of item [1] or is prepared by the method according to any one of item [2 ].

In the context of the present invention and in preferred embodiments, the heavy metal ions include Cd (II), Cu (II), Gr (VI), Ni (II) and As (V).

The invention has the beneficial effects that:

1) polyacrylamide is used as a matrix, hydroxymethylation is sequentially carried out to prepare hydroxymethylated polyacrylamide, and then strong ligand dithio carboxyl (-CSS-) of heavy metal ions is introduced into the hydroxymethylated polyacrylamide to prepare dithio carboxylated polyacrylamide, which not only can trap Cu (II) through chelation, but also can accelerate the condensation and settlement of chelated precipitates through the actions of self adsorption bridging, net trapping, rolling sweeping and the like, so that the Cu (II) in the wastewater can be effectively removed;

2) the dithio-carboxylated polyacrylamide can be used as a main body to load yeast surfactants and ferric citrate, so that the adsorbent is endowed with a ternary structure, and the range and the performance of the adsorbent capable of adsorbing heavy metal ions are enhanced;

3) the method comprises the following steps of (1) fermenting and culturing the marine yarrowia lipolytica in the later period of several periods to prepare fermentation liquor, so that lipopeptide surfactant components can be extracted, particularly, under the condition that ethanol and ebelanone are added into a fermentation culture medium, the extraction rate of the lipopeptide surfactant components is remarkably improved, the extraction rate of the dry matter surfactant can reach over 600mg/L, and the extraction rate of active components is remarkably improved;

4) the adsorbent formed by compounding the marine yarrowia lipolytica surfactant, the ferric citrate and the dithio-carboxylated polyacrylamide has obvious adsorption and aggregation effects on heavy metal ions, and has obvious adsorption effects on heavy metal ions in wastewater and sewage;

5) this application forms the adsorbent ternary structure who is used for getting rid of the heavy metal with dithio carboxylation polyacrylamide adsorption yeast surfactant and ferric citrate, on the basis that improves resin adsorption capacity, give the adsorbent synchronous adsorption get rid of heavy metal ion like Cd (II), Cu (II), Gr (VI), Ni (II) and As (V) the characteristic, and show good reabsorption performance to above-mentioned heavy metal ion, both solved the easy problem that is difficult to separate after reunion and the use of hydroxyl iron, improve the ability of modified polyacrylamide resin adsorption heavy metal ion with the help of hydroxyl iron and yeast surfactant again, and good reabsorption performance can improve the life of adsorbent.

The invention adopts the technical scheme to provide the model essay, makes up the defects of the prior art, and has reasonable design and convenient operation.

Drawings

In order to make the aforementioned and other objects, features, and advantages of the invention, as well as others which will become apparent, reference is made to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram showing the adsorption removal effect of the adsorbent of the present invention on heavy metal ions;

FIG. 2 is a schematic diagram of the re-adsorption of heavy metal ions by the adsorbent of the present invention.

Detailed Description

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The present invention uses the methods and materials described herein; other suitable methods and materials known in the art may be used. The materials, methods, and examples described herein are illustrative only and are not intended to be limiting. All publications, patent applications, patents, provisional applications, database entries, and other references mentioned herein, and the like, are incorporated by reference herein in their entirety. In case of conflict, the present specification, including definitions, will control.