The method of purification of waste water from arsenic

 

(57) Abstract:

The invention relates to methods of sewage purification from arsenic and can be used on non-ferrous metallurgy and chemical industry. The implementation of the method provides for the removal of arsenic by adsorption on organo-mineral sorbent-based iron hydroxide, containing also perchlorovinyl, of the following composition: iron hydroxide 75-83 wt.%, perchlorovinyl 17-25 wt. %. The method allows for the purification of wastewater to the level of the MPC is characterized by its simplicity and efficiency. table 1.

The invention relates to methods of sewage purification from arsenic and may find application in the enterprises of nonferrous metallurgy, the chemical industry and in the technology of semiconductor materials.

Known methods of deposition of arsenic in the form of insoluble compounds. As the precipitating tested a wide range of reagents: salts and oxides of alkaline earth and transition metals, phosphate and salpicaduras materials, ashes, slags and some organic compounds.

Use as a precipitator of calcium hydroxide at a temperature of 80-90oC and pH 6-8 by reducing the concentration of arsenic from 200 to 1 or sodium carbonate [2], as well as a mixture of lime and fly ash in alkaline environment [3].

These methods do not require the use of expensive reagents, however, do not allow to reach the level of cleaning solution, corresponding to the level of MCL (0.05 mg/DM3).

There is a method of electrochemical treatment of wastewater production of gallium arsenide with arsenic 3-80 mg/DM at pH 6-7 [4]. The process is carried out in the cell with a soluble metal anode at current density of 0.1-0.4 a/dm. is the residual arsenic in the filter at the level of sanitary norms. However, the high energy consumption of 3.5-10 kWh/m3and the selection arsina cars make use of this method. Possible extraction waste water from arsenic. As extractants used carbon tetrachloride, tributyl phosphate, high molecular weight alcohols, ketones, ethers and esters [5]. The disadvantage of extraction methods for solving this problem is the relatively high cost of the reagents, their toxicity, fire and explosion hazards, as well as lack of information about recycling reextractors and losses extractants. The most promising application area extraction processing on concentri what is ion exchange. There is a method of applying an organic resin KB-4-10P Ti - ion form, ANKB in Fe - ion-exchange form, which allows to reduce the concentration of arsenic in solution with 80 to 0.3 - 0.6 mg/DM3- [6].

You know the proposal to apply for the removal of arsenic ion-exchange materials based on iron hydroxides, titanium, copper, magnesium, zinc and Nickel, granulated by the method of freezing [7,8]. These sorbents were tested on modular solutions and natural waters arsenic 6-20 mg/dm. In neutral, weakly acidic environments, these samples can purify up to 600 column volumes of a solution to the MPC level. Lack of cleaning method using the above hydroxide ion is larger flow of material caused by mechanical destruction of the granules in cycles of sorption-desorption.

The closest in technical essence and the achieved result, i.e., the prototype of the present invention is a method of purification of waste water from arsenic, including sorption on the sorbent BPS-1. In this way the sorption of lead on drevesnoopilochnyh sorbent BPS-1, which is obtained by precipitation of iron hydroxide (III) in the pores of the wood carrier with an alkaline reagent at ignoreme is passing the solution through a bed of sorbent, elution of arsenic is performed with the acid solution, followed by ashing and briquetting of the sorbent.

The disadvantage of this method is a single sorbent and low treatment efficiency due to the low content of active component in the used sorbent.

The objective of the invention is to increase the efficiency of wastewater treatment for arsenic due to the possibility of application of the sorbent capable of regeneration.

The problem is solved by applying a composite of organic and mineral sorbent-based iron hydroxide, which is obtained by the method of [10] , including the spraying of organic suspensions, consisting of powder of inorganic sorbent and solution perchlorovinyl (chlorin fiber) in dimethylformamide in water.

Organic-mineral sorbent-based iron hydroxide having high sorption ability of the inorganic phase of the sorbent with respect to arsenic will allow to achieve a high degree of cleaning and the application of the inorganic binder is a polymer, it will give the opportunity to repeatedly operate the sorbent.

Application of organic and mineral sorbent-based hydroxide GWU inorganic component of the sorbent (iron hydroxide) ions of arsenic.

The removal of arsenic is to be in the range of pH 4 to 8, due to the properties of the hydroxide of iron.

Desorption of arsenic is performed with the sodium hydroxide solution with a concentration of 40 g/DM, with the destruction of the sorbent is not happening, so you can use it repeatedly. The eluate after column contains only ions of arsenic. Regeneration of the sorbent taken in the method prototype is not possible because the processing of acid will lead to the dissolution of iron hydroxide, and alkaline elution of arsenic will cause swelling and degradation of wood media. In addition, the acidic eluate contains both arsenic and iron ions requiring disposal.

Use for treatment of wastewater from organic arsenic sorbent on the basis of hydroxide of iron will intensify the process of sewage treatment, as the share of the active component in the sorbent is 80% compared with 8% of the known (BPS-1).

The application of the proposed method of sewage purification from arsenic leads to new and unexpected results is possible desorption of arsenic from the sorbent, and hence its repeated operation, and also to increase the productivity and the one above, than in the known BPS-1. Analysis of arsenic in solution was performed according to the method [11]. The effectiveness of this method of wastewater treatment for arsenic and the necessity of the stated conditions for achieving goals is illustrated by the following examples.

Example 1.

At 1.0 organic sorbent on the basis of iron hydroxide obtained by the method of [10], including spraying organic suspension consisting of a powder of iron hydroxide and the solution perchlorovinyl (chlorin fiber) in dimethylformamide in water, were placed in 50 cm of a solution of sodium arsenate concentration of arsenic 1.5 mg/DM at pH = 3. The content of iron hydroxide in the sorbent 80%, the rest of perchlorovinyl. The next day the solution was separated from the sorbent and analyzed. The magnitude of the distribution coefficient (Kd) was 103.

Example 2.

20 DM3sorbent-based iron hydroxide, containing 80% of iron hydroxide (rest - binder - perchlorovinyl) were loaded into a column with a diameter of 150 mm, the Height of the layer of sorbent was approximately 2 meters Through the column missed the industrial wastewater with concentrations of arsenic from 0.3 to 2.5 mg/DM at pH close to 4. The filtration rate was 120-140 DM/PM Desorption made"ptx2">

Results purification of waste water from arsenic and some of the characteristics given in the table.

As can be seen from the table, the proposed method is 1.9 times more efficient than the known, leads to increased performance of the cleaning process 1.7 times due to the greater bulk of the mass of the sorbent, and most importantly, able to work in cycles of sorption-desorption.

The arsenic content in the effluent drops to modern levels of MCL (0.05 mg/DM3).

The proposed method can be used when removing arsenic from process solutions, wastewater and natural waters.

Sources of information

1. Scrabman B. I., Yurkova C. M., Pavlova E. I., Precipitation of arsenic from fluorine and fluorine-containing waste water//Chemical industry, 1974, 15, page 76.

2. Polyakov, M. L., wastewater treatment hydrometallurgical plant khovu-Aksy from arsenic Tsvet, 1965 r., No. 19, page 32.

3. Rebrov T. I., Kwiatkowski A. N., Kadyrov Z 0.- Proceedings Of Kasamahan. Alma-ATA, 1970,14, pages 62-65.

4. Kozhemyakin C. A., Gradova Acting, Pochtarev A. N., Electrocoagulation wastewater treatment method from arsenic and suspended particles //J. struct. Dokl. II all-Union conference "Chemistry and technologistics and waste waters from arsenic. - M.: Totipalmate, 1977,page 32.

6. Official. Opponents M. T., Lebedev, K. B., Antonov, C. N., Ozerov, A. I., treatment and control of wastewater enterprises of nonferrous metallurgy. M.: metallurgy, 1983, page 191.

7. Pakholkov B. C., Markov, C. F., Granulated iron hydroxide of its physico-chemical properties and application for cleaning thermal and natural water from arsenic Chemistry and technology of inorganic sorbents: Meiwes. collected scientific articles. Tr. /VT.polytechn. in so Perm, 1980,S. 26-33.

8. Nureyev A. N., Jabbarov H. A., Gaibov, M. Y., Inorganic sorbent for selective removal of arsenic from natural water Chemistry and technology of inorganic sorbents: Meiwes. collected scientific articles.Tr. / VT.polytechn.in-so - Perm, 1980, pp. 34-39.

9. Wood-inorganic sorbent BPS-1 (iron (III) hydroxide on granulated wood) // Catalog-Handbook of Inorganic sorbents", Perm, 1988, pp. 49-50.

10. Onorin S. A., vol'hin centuries, Secunia E. A., Alpatova E. C., Organic sorbents on the basis of titanium dioxide for selective extraction of lithium from solutions // J. struct.Dokl. - Apatity, 1988, pp. 101 - 102.

11. Nemotek A. A., Analytical chemistry of arsenic. M: Nauka, 1976, page 224.

The method of purification of waste water from Michio material use organic sorbent composition, wt.%:

The iron hydroxide - 75 - 83

Perchlorovinyl - 17 - 25

 

Same patents:

The invention relates to magnetic treatment of liquids and can be used for intensification of various technological processes, such as prevention of scale on the heating surfaces of process apparatus, purification and clarification of process water

The invention relates to magnetic treatment of liquids and can be used for intensification of various technological processes, such as prevention of scale on the heating surfaces of heat exchangers, purification and clarification of process water

The invention relates to water treatment systems and water heating

The invention relates to magnetodynamics water treatment and liquid solutions and can be used in construction, agriculture for irrigation of plants and reduction of soil salinity in utilities to protect equipment from scale formation and so on

The invention relates to a device for the preparation of water for drinking to water supply

The invention relates to a device for the preparation of water for drinking and technical water supply

The invention relates to processes for the preparation of water for drinking and technical water supply, wastewater treatment, disinfection and water activation

The invention relates to sorption wastewater and can be used in the pulp and paper industry, petrochemical industry, metallurgy, food and other industries

The invention relates to the field of cleaning fluids and can be used to improve environmental and techno-economic characteristics of moving liquids and fuels & lubricants

The invention relates to magnetic treatment of liquids and can be used for intensification of various technological processes, such as prevention of scale on the heating surfaces of process apparatus, purification and clarification of process water

The invention relates to magnetic treatment of liquids and can be used for intensification of various technological processes, such as prevention of scale on the heating surfaces of heat exchangers, purification and clarification of process water

The invention relates to water treatment systems and water heating

The invention relates to magnetodynamics water treatment and liquid solutions and can be used in construction, agriculture for irrigation of plants and reduction of soil salinity in utilities to protect equipment from scale formation and so on

The invention relates to a device for the preparation of water for drinking to water supply

The invention relates to a device for the preparation of water for drinking and technical water supply

The invention relates to processes for the preparation of water for drinking and technical water supply, wastewater treatment, disinfection and water activation

The invention relates to sorption wastewater and can be used in the pulp and paper industry, petrochemical industry, metallurgy, food and other industries

The invention relates to the field of cleaning fluids and can be used to improve environmental and techno-economic characteristics of moving liquids and fuels & lubricants

The invention relates to sorbents, in particular solid polymeric sorbent, and methods for their preparation to extract radioactive isotopes and can be used in the nuclear industry to obtain fragmentation of Mo-99 from uranylacetate solution (UO2SO43H2O) a homogeneous solution nuclear reactors for medicine
Up!