RU2042644C1 - Method of removing hydrogen sulfide from water - Google Patents

Abstract

FIELD: water supply. SUBSTANCE: underground water, having a hydrogen sulfide content up to 50 mg/l, is saturated with an oxidizer and filtered through beds of anthracite of 2- 4 mm in grain size and 450-550 mm in height and beds of quartz sand of 0.6-1.8 mm in graininess and of 250-350 mm in height. The metal grid made up as a spiral of 200-250 mm in height and 3.5x3.5 mm in mesh size is arranged vertically in the bottom space of the bed. EFFECT: improved purifying. 3 cl

Description

 The invention relates to a technology for the purification of natural groundwater from hydrogen sulfide and can be used in the preparation of groundwater for the supply of small towns or detached residential buildings.

A known method of purifying water from hydrogen sulfide, including aeration of water, followed by filtration through an unburied catalytic charge from crushed magnetite [1]
However, this method can be used at relatively low initial concentrations of hydrogen sulfide in the treated water, and at concentrations greater than 30 mg / l, the degree of purification does not exceed 84% i.e. water after such treatment cannot be used for drinking.

 The technical result achieved closest to the invention is the method of purifying water from hydrogen sulfide [2] which offers chlorination of water with its subsequent filtration through an activated carbon layer. When filtering through a layer of activated carbon of chlorinated water, a catalytic reaction occurs with the removal of sulfur compounds. The source water (underground) with a concentration of dissolved hydrogen sulfide in the range of 0.1-6.0 mg / l is saturated with gaseous chlorine in front of the activated carbon layer from the ratio of chlorine to hydrogen sulfide (8-24): 1 and filtered through an activated carbon layer with a height of about 600 mm . The sulfur content in purified water is less than 0.1 mg / L. This method can be used for closed systems, preventing water from contacting the environment, maintaining bacteriological purity and at the same time solving the problem of environmental pollution.

 However, the use of the method is limited to the use of high concentrations of chlorine for the oxidation of hydrogen sulfide. At high initial concentrations of hydrogen sulfide (more than 6.0 mg / l), the problem arises of removing excess chlorine in purified water. In addition, the method is technologically complicated, since it requires the saturation of water with chlorine in airtight conditions, it provides an activated carbon regeneration system and a system for saturating water with gaseous chlorine.

 The technical result of the proposed technical solution is to increase the degree of water purification at elevated concentrations of hydrogen sulfide while simplifying operating conditions.

 In a method for purifying water from hydrogen sulfide by filtering water pre-saturated with an oxidizing agent through a catalytic charge according to the invention, the water is successively filtered through an anthracite loading layer, through an anthracite layer with a metal mesh and silica sand.

 As a load, you can use a layer of anthracite with a height of 450-550 mm with a grain size of 2-4 mm.

 The iron mesh can be used in the form of a spiral vertically located in the lower part of the anthracite loading volume, the height of the spiral is 200-250 mm with cells 3.5x3.5 mm.

 Quartz sand can be used with a grain size of 0.6-1.8 mm and a layer height of 250-350 mm.

 The technology of the method is as follows. Underground water containing dissolved hydrogen sulfide, in a dispersed state, is supplied from a height of about 200 mm to an unfilled load from anthracite. When filtered, air saturated with oxygen in the air contacts the surface of anthracite grains, and hydrogen sulfide is removed by oxidizing it on the surface of anthracite, and it has been experimentally established that oxidation of hydrogen sulfide by atmospheric oxygen on anthracite occurs by two mechanisms: chemical and electrochemical. The first mechanism occurs when other known catalysts are used, and the second manifests itself due to the electronic conductivity of anthracite. Micro galvanic cells are formed on its surface, where oxygen reduction reactions correspond to cathodic sections, and hydrogen sulfide oxidation corresponds to anodic ones. Due to this, the oxidation of hydrogen sulfide proceeds more fully and ensures its low residual concentrations. In the known prototype method, chlorinated water is passed through a layer of activated carbon, on the surface of which hydrogen sulfide is catalyzed into elemental sulfur by carbon and chlorine, i.e. other components of the hydrogen sulfide removal process are used. In the proposed method, an environmentally friendly oxidizing agent uses atmospheric oxygen and a simpler method of sprinkling, rather than the saturation of chlorine through special devices. In the known method, a layer of activated carbon with a height of up to 900 mm is used. The proposed method uses cheaper material anthracite layer height up to 550 mm Hydrogen sulfide unoxidized by atmospheric oxygen is in contact with the metal network and forms iron sulfide. Using a grid in the form of a vertically arranged spiral allows you to more efficiently and evenly distribute the grid in a cylindrical filter volume, the cell dimensions of 3.5x3.5 mm exclude the formation of voids in the volume of anthracite load, the spiral height of up to 250 mm provides complete "binding" of hydrogen sulfide. Hydrogen sulfide oxidation products are delayed when filtering the treated water through a quartz sand layer with a layer height of up to 350 mm with a grain size closer to 1.8 mm and a layer height of 250 mm with a grain size closer to 0.6 mm.

 PRI me R 1. Underground water with a hydrogen sulfide content of 50 mg / l through a shower mesh is fed to an unfilled anthracite load from a height of 200 mm. The grain size of the load is 2 mm, the layer height is 450 mm, the height of the spiral from a metal mesh is 200 mm, the cell size is 3.5x3.5 mm in the lower volume of the anthracite load. Filtering speed 1 m / h. A sand layer of 250 mm with a grain size of predominantly 0.6 mm. Hydrogen sulfide was not detected in the filtrate. When removing a layer of sand, the water after filtration is "muddy". When removing the metal mesh in the filtrate 18 mg / l of hydrogen sulfide.

 PRI me R 2. Water with a hydrogen sulfide content of 35 mg / l through a shower mesh is fed to a non-flooded anthracite load from a height of 200 mm. The grain size of the feed is 3 mm, the layer height is 500 mm, the height of the spiral from a metal mesh is 225 mm, the mesh sizes are 3.5x3.5 mm in the lower volume of the anthracite load. Filtering speed 1 m / h. A sand layer of 300 mm with a grain size of predominantly 1.2 mm. Hydrogen sulfide was not detected in the filtrate. When removing a layer of sand, the water after filtration is "muddy". When removing the metal mesh in the filtrate 12.5 mg / l of hydrogen sulfide.

 PRI me R 3. Water with a hydrogen sulfide content of 27.5 mg / l through a shower mesh is fed to an unfilled anthracite load from a height of 200 mm. The grain size of the feed is 4 mm, the layer height is 550 mm, the height of the spiral from a metal mesh is 250 mm, the mesh sizes are 3.5x3.5 mm in the lower volume of the anthracite load. Filtering speed 1 m / h. A sand layer of 350 mm with a grain size of predominantly 1.8 mm. The concentration of hydrogen sulfide in the filtrate is 0.1 mg / L. When removing a layer of sand, the water after filtration is "cloudy" and the hydrogen sulfide content of 1.3 mg / L. When removing the metal mesh in the filtrate 8.5 mg / l of hydrogen sulfide.

 Only the proposed sequence of water purification provides an increase in the degree of purification from hydrogen sulfide at its increased concentrations in water while simplifying operating conditions.

Claims (4)

 1. METHOD FOR WATER PURIFICATION FROM HYDROGEN SULPHIDE by filtering water pre-saturated with an oxidizing agent through a catalytic charge, characterized in that the water is successively filtered through loading layers of anthracite, anthracite with a metal mesh and quartz sand.  2. The method according to claim 1, characterized in that as the load using a layer of anthracite with a height of 450 550 mm with a grain size of 2 4 mm  3. The method according to claims 1 and 2, characterized in that they use an iron mesh in the form of a vertically arranged spiral in the lower part of the volume of anthracite load with a height of 200,250 mm with cells of 3.5 x 3.5 mm.  4. The method according to claim 1, characterized in that they use a layer of quartz sand with a height of 250 to 350 mm, grain size of 0.6 to 1.8 mm.