阅读说明：本技术 一种用于去除三价砷和六价铬污染的施氏矿物 (Shi mineral for removing pollution of trivalent arsenic and hexavalent chromium ) 是由 王小明 应虹 黄坤 冯雄汉 严玉鹏 刘凡 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种用于同时去除三价砷和六价铬污染的施氏矿物,它是按以下方法制备的：将去离子水加热至50-70℃,然后加入FeCl<Sub>3</Sub>·6H<Sub>2</Sub>O和Na<Sub>2</Sub>SO<Sub>4</Sub>,将混合溶液保温搅拌5-20min,将反应后得到的沉淀冷却至室温后转移到透析袋中,透析5-10天至电导率低于100μs·cm<Sup>-1</Sup>,离心干燥后得到比表面积为100-300m<Sup>2</Sup>·g<Sup>-1</Sup>的粉末。本发明中施氏矿物对As(III)和Cr(VI)二元污染物共存体系的砷、铬去除效果好,去除表现为氧化还原-吸附联合作用,即在降低水体中砷和铬浓度的同时可进一步减小两种污染元素的毒性。(The invention discloses a schneiderian mineral for simultaneously removing trivalent arsenic and hexavalent chromium pollution, which is prepared by the following method: heating deionized water to 50-70 ℃, and then adding FeCl 3 ·6H 2 O and Na 2 SO 4 Stirring the mixed solution for 5-20min under heat preservation, cooling the precipitate to room temperature, transferring into dialysis bag, dialyzing for 5-10 days until the conductivity is lower than 100 μ s cm ‑1 After centrifugal drying, the specific surface area is 100-300m 2 ·g ‑1 The powder of (4). In the invention, the Schneider mineral pairs As (III) and Cr (VI)The arsenic and chromium removal effect of the element pollutant coexistence system is good, and the removal is represented by the combined action of oxidation reduction and adsorption, namely, the toxicity of two pollution elements can be further reduced while the concentrations of arsenic and chromium in the water body are reduced.)

1. A schlerian mineral for removing trivalent arsenic and hexavalent chromium contamination, characterized by being prepared by the following method: heating deionized water to 50-70 ℃, and then adding FeCl₃·6H₂O and Na₂SO₄Stirring the mixed solution for 5-20min under heat preservation, cooling the precipitate to room temperature, transferring into dialysis bag, dialyzing for 5-10 days until the conductivity is lower than 100 μ s cm^-1After centrifugal drying, the specific surface area is 100-300m²·g^-1The schneiderian mineral powder of (1).

2. The schneiderian mineral for the removal of trivalent arsenic and hexavalent chromium contamination of claim 1, wherein: in the mixed solution, FeCl₃·6H₂O and Na₂SO₄The concentrations of (A) and (B) are 0.3-0.7% and 0.1-0.2%, respectively.

3. Use of the schneiderian mineral of claim 1 or 2 for the removal of trivalent arsenic and hexavalent chromium contamination in a body of water.

4. A method for removing trivalent arsenic and hexavalent chromium pollution in water is characterized in that: adding the schlerian mineral powder prepared according to claim 1 or 2 to 0.01-0.1M NaNO₃In the background electrolyte, the electrolyte is constantly stirred and balanced for 10 to 60 minutes under the conditions of pH 5 and 20 to 30 ℃, and then is added into water bodies polluted by trivalent arsenic and hexavalent chromium for treatment.

5. The method of removing trivalent arsenic and hexavalent chromium contamination in a body of water of claim 4, wherein: the treatment time was 4 hours.

Technical Field

The invention belongs to the field of pollution treatment, particularly relates to a schwertmannite for removing pollution of trivalent arsenic and hexavalent chromium, and also relates to a method for removing pollution of trivalent arsenic and hexavalent chromium in a water body.

Technical Field

With the rapid development of industrial technologies, heavy metal pollution caused by industrial production wastewater, pesticides, medical wastes and the like gradually becomes a global environmental problem. Wherein, heavy metal arsenic is one of elements which are extremely harmful to human bodies, can not be degraded, is easy to be continuously accumulated through a food chain and geochemical cycle, and poses great threat to an ecosystem. Arsenic exists in natural water mainly in two forms of As (III) and As (V), wherein the toxicity of the As is 60 times higher than that of the As (III), the As is highly mobile, and the As is not easily removed by adsorption of an adsorbent. Chromium is a grayish transition metal, widely distributed in the earth crust, with Cr (VI) and Cr (III) being the most common in solution environments, and Cr (VI) being 100-1000 times more toxic than Cr (III). The long-term exposure to Cr (VI) pollution can bring great health hazards to human bodies, such as gastrointestinal tract and skin diseases, abnormal blood functions and the like. In recent years, composite type pollution of As and Cr often occurs in polluted water bodies, particularly in acid mine wastewater, pigment manufacturing industrial wastewater and the like. Therefore, how to efficiently treat the As and Cr composite pollution with high toxicity and high carcinogenicity has important environmental significance for improving the current situation of underground water heavy metal pollution in a mining area.

The adsorption technology is one of the important methods for efficiently treating heavy metal pollution in a mining area at present, an insoluble solid material with a large specific surface area is used as an adsorbent, and a pollution element in water is transferred to a solid phase through the actions of physical adsorption, chemical adsorption or ion exchange and the like, so that the purpose of removing the pollutant is achieved. Among the methods for removing arsenic and chromium contamination, the adsorption method is one of the most widely used methods, and examples of the adsorbent for arsenic include activated carbon, activated aluminum, clay, and iron oxide, and examples of the adsorbent for chromium include activated carbon and iron oxide. In addition, since the toxicity of Cr (VI) is 1000 times that of Cr (III) and the toxicity of As (III) is 60 times that of As (V), Cr (VI) is often reduced to Cr (III) and As (III) is oxidized to As (V) in the actual treatment process, thereby reducing the toxicity of pollutants.

The schneiderian mineral is sulfate-rich hydroxyl iron oxide which is common in an acid mine wastewater environment, and has larger specific surface area and surface OH site density and high sulfate content, so that the schneiderian mineral has good adsorption and exchange removal capacity on heavy metal elements. In recent years, the schneiderian mineral is widely used for treating polluted water as an environment repairing material, and shows good effect, particularly for removing arsenic and chromium, and the independent enrichment amount of the schneiderian mineral can reach 812ppm (Cr) and 6740ppm (As). In addition, the schlerian mineral not only has the function of an adsorbent but also can be used as a catalyst under certain conditions, for example, the schlerian mineral can catalyze the reduction of Cr (VI) into Cr (III) through interface action, thereby reducing the toxicity of the schlerian mineral. Therefore, the Schwerer mineral with unique structure and surface characteristics can be used for efficiently removing As (III) and Cr (VI) in the composite polluted water body and reducing the toxicity of the composite polluted water body, so that an effective way is provided for treating the polluted wastewater rich in As (III) and Cr (VI).

Disclosure of Invention

The first purpose of the invention is to provide a schwerk mineral for removing the pollution of trivalent arsenic and hexavalent chromium, and the second purpose of the invention is to provide the application of the schwerk mineral in removing the pollution of trivalent arsenic and hexavalent chromium in water. The method for treating pollution of trivalent arsenic and hexavalent chromium has the advantages of low cost, good treatment effect, simple operation and the like.

A schlerian mineral for removing trivalent arsenic and hexavalent chromium pollution is prepared by the following steps: heating deionized water to 50-70 ℃, and then adding FeCl₃·6H₂O and Na₂SO₄Stirring the mixed solution for 5-20min, cooling the precipitate to room temperature, transferring into dialysis bag, dialyzing for 5-10 days until the electric conductivity is lower than 100 μ s cm^-1Centrifugal dryingAfter drying, the specific surface area is 100-300m²·g^-1The schneiderian mineral powder of (1).

Preferably, in the mixed solution, FeCl₃·6H₂O and Na₂SO₄The concentrations of (A) and (B) are 0.3-0.7% and 0.1-0.2%, respectively.

The Schwerner mineral is applied to removing the pollution of trivalent arsenic and hexavalent chromium in water.

A method for removing the pollution of trivalent As and hexavalent Cr in water body includes such steps as adding the prepared schneishi mineral powder to 0.01-0.1M NaNO₃In the background electrolyte, the electrolyte is constantly stirred and balanced for 10 to 60 minutes under the conditions of pH 5 and 20 to 30 ℃, and then is added into water bodies polluted by trivalent arsenic and hexavalent chromium for treatment. The treatment time was 4 hours.

Compared with the prior art, the application of the invention has the following advantages:

firstly, the Schneider minerals have good arsenic and chromium removal effect on an As (III) and Cr (VI) binary pollutant coexistence system.

Secondly, the removal of As (III) and Cr (VI) by the Schwerer minerals in the invention is represented by a combined redox-adsorption effect, namely, the toxicity of the two pollution elements can be further reduced while the concentrations of arsenic and chromium in the water body are reduced.

Thirdly, the materials in the invention are simple and easy to obtain, the trivalent ferric salt and the sodium salt are used as raw materials, the mild one-step hydrothermal method is adopted to synthesize the Shih mineral, the process flow is simple, the operation is convenient and fast, and the production cost is lower.

Drawings

FIG. 1 is a characteristic X-ray diffraction pattern (XRD) of the Schneider mineral.

FIG. 2 is a scanning electron micrograph of Schlemm's mineral.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments and drawings for facilitating the understanding of the present invention, but they are not intended to limit the present invention.