阅读说明：本技术 一种用槐花米制备复合零价铁脱氯药剂的方法及应用 (Method for preparing composite zero-valent iron dechlorination medicament from sophora flower rice and application ) 是由 林爱军 谭笑 杨文杰 刘家豪 王金航 于 2019-05-25 设计创作，主要内容包括：本发明涉及环境修复领域,特别涉及一种可降解含氯有机物的用槐花米制备复合零价铁脱氯药剂的方法及应用。其制备方法包括对生物炭进行预处理、制备槐花米溶出液、零价铁的制备及负载等步骤。所制备的复合零价铁脱氯药剂具有负载量大、分散性好、负载均匀、比表面积大等特点,在对含氯有机污染物的还原脱氯方面表现出优异的反应活性,具有很好的降解效果,且在修复过程中不会对环境造成二次污染。(The invention relates to the field of environmental remediation, and in particular relates to a method for preparing a composite zero-valent iron dechlorination medicament from sophora japonica rice, which can degrade chlorine-containing organic matters, and an application of the dechlorination medicament. The preparation method comprises the steps of pretreatment of the biochar, preparation of the sophora flower rice dissolution liquid, preparation of zero-valent iron, loading and the like. The prepared compound zero-valent iron dechlorination medicament has the characteristics of large loading capacity, good dispersity, uniform loading, large specific surface area and the like, shows excellent reaction activity in the aspect of reductive dechlorination of chlorine-containing organic pollutants, has good degradation effect, and does not cause secondary pollution to the environment in the repairing process.)

1. A method for preparing a composite zero-valent iron dechlorination medicament by using sophora japonica rice and application thereof are characterized in that the preparation method comprises the steps of pretreating biochar, preparing sophora japonica rice dissolution liquid, preparing and loading zero-valent iron and the like.

2. The method for preparing the compound zero-valent iron dechlorination medicament from sophora japonica rice according to claim 1, wherein the raw material for preparing the biochar in the process of pretreating the biochar is silkworm excrement, and the preparation condition is that the biochar is subjected to oxygen-limited pyrolysis at the temperature of 500 ℃ for 2 hours.

3. The method for preparing the dechlorination medicament of the zero-valent iron from the sophora japonica rice as claimed in claim 1, wherein the biochar used in the process of pretreating the biochar is 100-300 mesh.

4. The method for preparing the zero-valent iron dechlorination reagent according to claim 1, wherein the microcrystalline cellulose solution used in the process of pretreating the biochar is 10-15 g/L.

5. The method for preparing the zero-valent iron dechlorination reagent according to claim 1, wherein the citric acid used in the process of pretreating the biochar is 0.20-0.25 g.

6. The method for preparing the compound zero-valent iron dechlorination medicament according to claim 1, wherein a small amount of calcium hydroxide is 0.3-0.7g and a small amount of borax is 0.05-0.2 g in the preparation process of the sophora flower rice leachate.

7. The method for preparing the compound zero-valent iron dechlorination reagent according to claim 1, wherein in the process of preparing the sophora flower rice leachate, the mixed solution of acetone and deionized water is prepared according to the volume ratio of 5: 1.

8. The method as claimed in claim 1, wherein the polymerization degree of polyethylene glycol used in the preparation of zero-valent iron is 3000-5000.

9. The method for preparing the dechlorination medicament of the compound zero-valent iron from the sophora japonica rice according to claim 1, wherein the FeSO ₄ -7H ₂ O used in the preparation process of the zero-valent iron is 2.5-5.0 g.

10. The method for preparing the dechlorination medicament of the compound zero-valent iron from the sophora japonica rice according to claim 1, wherein the freezing temperature in the freeze drying process in the processes of preparing and loading the zero-valent iron is below-15 ℃, and the drying pressure is below 1000 pa.

Technical Field

The invention relates to the field of environmental remediation, in particular to a method for preparing a composite zero-valent iron dechlorination medicament from sophora japonica rice, which can degrade chlorine-containing organic matters, and an application of the dechlorination medicament.

Background

Chlorine-containing organic substances including chlorinated hydrocarbons, chlorinated aromatic hydrocarbons, organochlorine pesticides, etc., which are an important class of recent chemical production raw materials and intermediates, are widely present in underground water and soil due to their use in large quantities and their high retention in the environment. Meanwhile, chlorine-containing organic pollutants pose serious threats to human life and environment, such as carcinogenicity and cytotoxicity to the central nervous system, immune system and endocrine system. The chlorine-containing organic matter has the characteristics of high residue and difficult degradation, the chlorine-containing organic matter is directly degraded by a conventional chemical oxidation method and is not thorough, and the reduction material is firstly subjected to reduction dechlorination and then is subjected to chemical oxidation, so that a good degradation effect can be achieved. Since the research of removing chlorine-containing organic matters in water by reducing zero-valent iron in the last 80 years, the dechlorination reduction of organic chloride by using a zero-valent iron material has become a research direction with wide attention at home and abroad due to the characteristics of simplicity, effectiveness and low cost.

²⁺The nanometer zero-valent iron has the characteristics of large specific surface area and strong adsorption capacity of nanometer materials, and because the bond state and the electronic state of the surface of the nanometer zero-valent iron are different from those in the interior of particles, and the coordination of surface atoms is incomplete, the active position of the surface is increased, and the nanometer zero-valent iron plays a good catalytic role in degrading the chlorine-containing organic matters.

However, the practical application of the nano zero-valent iron also has some problems that the nano zero-valent iron is easy to aggregate under the action of van der waals force and magnetic force to reduce the reactivity, is easy to oxidize, is easy to lose efficacy in the storage and transportation processes, and influences the use effect. In order to solve the above problems, some researchers have tried to prepare zero-valent iron composite materials to improve the characteristics thereof, for example, zero-valent iron is loaded on materials such as expanded graphite and activated carbon, but the invention provides a composite zero-valent iron dechlorination medicament prepared by loading zero-valent iron on biochar, and good effects are achieved.

Disclosure of Invention

The invention aims to provide a method for preparing a composite zero-valent iron dechlorinating medicament by using sophora flower rice and application thereof.

In order to achieve the purpose, the invention is realized by the following technical scheme:

1) Weighing 0.5g of dry biochar, adding the dry biochar into 30mL of prepared microcrystalline cellulose solution, adding a certain amount of citric acid, performing ultrasonic dispersion in an ultrasonic cleaner for 20-40min, and then performing constant-temperature oscillation in a constant-temperature oscillation incubator at 25 ℃ for 3-6 h.

2) After oscillation, placing the mixture in a 50mL high-pressure-resistant sealed reaction kettle, reacting at constant temperature of 200 plus materials and 240 ℃ for 10-15h, naturally cooling to room temperature, washing with absolute ethyl alcohol, performing centrifugal separation, and drying in an oven at 70-80 ℃ for 12h at constant temperature to finish the pretreatment of the biochar.

3) Dissolving a small amount of calcium hydroxide and borax into 150ml of mixed solution of acetone and deionized water, stirring uniformly, adding 10g of sophora flower rice, heating, slightly boiling for 20-30min, filtering residues while hot, and performing rotary evaporation and concentration on the residual liquid at 55 ℃ until the volume is reduced to 1/3 to obtain sophora flower rice dissolving liquid.

4) Polyethylene glycol is dissolved in ultrapure water to prepare 15g/L dispersant solution.

5) Weighing a small amount of FeSO ₄ & 7H ₂ O, dissolving in 50mL of the dispersant solution obtained in the step 4), sealing, placing in an ultrasonic cleaning instrument, ultrasonically dispersing for 20-40min, adding 1g of the pretreated biochar, and magnetically stirring for 30min under the protection of nitrogen.

6) And putting the prepared sophora flower rice dissolution liquid into a separating funnel, slowly dropping the liquid into the flask and continuously stirring for 20-40 min. The prepared material is washed by absolute ethyl alcohol, centrifugally separated, frozen and dried for 12 hours, and the compound zero-valent iron dechlorination medicament is prepared.

Preferably, the raw material for preparing the dried biochar in the step 1) is silkworm excrement, and the preparation condition is that the raw material is subjected to oxygen-limited pyrolysis at the temperature of 500 ℃ for 2 hours.

Preferably, the dried biochar in the step 1) is 100-300 meshes, and preferably is 200-300 meshes.

Preferably, the microcrystalline cellulose solution in the step 1) is 10-15 g/L.

Preferably, the amount of citric acid in step 1) is 0.20-0.25 g.

Preferably, the small amount of calcium hydroxide in the step 3) is 0.3-0.7g, and the small amount of borax is 0.05-0.2 g.

Preferably, the acetone and deionized water mixed solution in the step 3) is prepared by the volume ratio of acetone to deionized water of 5: 1.

Preferably, the polymerization degree of the polyethylene glycol in the step 4) is 3000-5000.

Preferably, the small amount of FeSO ₄ & 7H ₂ O in the step 5) is 2.5-5.0 g.

Preferably, the freezing temperature in the freeze drying process in the step 6) is below-15 ℃, preferably below-30 ℃, preferably below-45 ℃; the drying pressure is 1000pa or less, preferably 100pa or less, preferably 10pa or less.

The technical progress achieved by the invention is as follows:

The biological carbon is pretreated, the active point positions of the biological carbon are increased to a large extent, the load point positions and the load degree of the nano zero-valent iron on the biological carbon can be increased, and the load capacity is improved.

The polyethylene glycol solution is used as a dispersing agent in the reaction process, the drug has low toxicity and good stability, the sophora flower rice dissolution liquid is used as a reduction chelating agent, the preparation efficiency of the nano zero-valent iron can be improved, the nano zero-valent iron particles can be uniformly loaded on the biochar, the dispersibility is good, the specific surface area of the nano zero-valent iron particles is increased, and the reaction activity of the drug on the aspect of reduction dechlorination of chlorine-containing organic pollutants is improved.

Drawings

FIG. 1 is a graph of the degradation rate of 1, 2-dichlorobenzene with the zero-valent iron dechlorination agent in example 1 of the present invention versus time.

FIG. 2 is a graph of the degradation rate of o-chlorophenol with zero-valent iron dechlorination agent in example 1 of the present invention versus time.

FIG. 3 is a graph of the degradation rate of 2, 4-dichlorophenol in the compound zero-valent iron dechlorination agent versus time in example 1 of the present invention.

Detailed Description