RU2170044C1 - Mineralized drinking water production process - Google Patents

Abstract

FIELD: food industry. SUBSTANCE: invention relates to production high-purity drinking waters used as mineralized therapeutic and table water and also as drinking and process water suitable for preparation of foods. Process consists in that tap water is subjected to primary purification and then to reverse-osmosis purification, acidified to pH 4.5-5.5, passed through double-bed filtration charge with velocity 1.2-7 cu.m/h. Double-bed charge consists of crushed quartz support and partly calcined dolomite with particle size 2.5-4.5 mm. When passed through filtration charge, water is saturated with calcium and magnesium hydrocarbonates until mineralization between 50 and 1500 mg/l is attained. Partly calcined dolomite is prepared by calcination of natural dolomite at temperatures of order of 850 C to give CaCO₃•MgO containing, vol %: CaCO₃ 60.0-70.0, free CaO 0.8-1.5, MgCO₃ 5.0-6.0, free MgO 20.0-30.0, and space minerals Ц the rest. EFFECT: reduced sodium chloride and sulfate adversely influencing human health leading to various vascular diseases. 1 tbl

Description

 The invention relates to the non-alcoholic and alcoholic industries, in particular to the preparation of high-purity waters used as mineral table water, drinking and process water for cooking, medical and dietary practice, and for the preparation of soft drinks and alcoholic beverages.

 A known method of producing potable water, comprising passing water through a filter medium with a nutrient substrate including dolomite, used to displace pathogenic bacteria from the filter medium (US Patent No. 5198114, C 02 F 1/28, 3/00, 1989 )

 A known method of producing drinking water "Elizabeth" (RU Patent N 2100941, A 23 L 2/38, 1997). The method consists in the fact that the natural mineral water of the Gdov aquifer is subjected to reverse osmosis treatment, after which it is mixed in a certain ratio with natural environmentally friendly mineral water to produce drinking water with a certain controlled content of potassium, sodium, magnesium, calcium cations, chlorine anions.

 A known method of producing high-quality drinking water (Author's certificate N 12105880, A 23 L 2/38, 1986), including rough cleaning of tap water, the operation of fine cleaning through ultrafiltration membranes, after which the water practically does not contain colloidal impurities and microorganisms and is characterized also low in organic matter. Then the water enters the reverse osmosis unit, where demineralized water is obtained, followed by the addition of salts to a total mineralization of 0.1 - 0.5 g / l. The resulting water can be used for the production of carbonated fruit drinks and in the alcohol industry. The concentrate obtained as a result of reverse osmosis water purification has a mineralization of 25-35% and is a product for the production of salts.

 The objective of the invention is to develop a method of purification of tap water, providing high-purity water with varying degrees of mineralization. As a result of the developed method, drinking water is obtained with a minimum content of sodium chlorides and sulfates, which adversely affect people's health, causing various vascular diseases.

The essence of the method lies in the fact that tap water is subjected to rough cleaning, then reverse osmosis treatment, acidified to pH 4.5-5.5, passed through a two-layer filtering charge at a speed of 1.2-7 m ³ / h. The two-layer loading consists of a substrate of crushed quartz and a layer of partially calcined dolomite with a grain size of 2.5 - 4.5 mm. In the process of passing through a filter charge, water is saturated with calcium and magnesium bicarbonates to a mineralization of 50 - 1500 mg / l.

Partially calcined dolomite is obtained by calcining natural dolomite at temperatures of the order of 850 ^° C. Compared with natural dolomite CaMg (CO ₃ ) ₂ , it partially neutralizes to CaCO ₃ * MgO. The mineralogical composition of the material is represented by the following compounds: CaCO ₃ - 60.0-70.0 vol. %, free CaO 0.8 - 1.5 vol.%, MgCO ₃ - 5.0 - 6.0 vol.%, free MgO - 20.0 - 30.0 vol.%, trace elements - the rest.

Physico-chemical characteristics of the material: actual density 3.33 g / ml, apparent density 1.14 g / ml, pH 11, solubility in H ₂ O - 0.27%.

 The principle of operation of the filter based on the filter load, consisting of a quartz substrate and a layer of partially calcined dolomite, is based on dissolving calcium carbonate and magnesium oxide in water in an acidic environment with the formation of calcium and magnesium bicarbonates.

The high efficiency of the filter is based both on the significant content of free MgO in partially calcined dolomite, which in this form has high activity, and on the increased reactivity of CaCO ₃ , due to its high porosity and fine distribution in partially calcined dolomite.

 An example implementation of the method.

 Tap water is passed through a filter with a granular sorption charge, which is a cylindrical tank made of 12Kh12N10T corrosion-resistant steel with a tubular type drainage device. The filter traps suspended solids present in tap water, eliminates odor, taste, and also reduces the chlorine content.

As download use:
1st layer - crushed quartz with a particle size of 2.0-3.0 mm;
2nd layer - Chemviron Corbon F-200 filter sorption material with a particle size of up to 1 mm.

 Overall dimensions of the filter: diameter 800 mm, height 2000 mm.

 Filter performance up to 6000 l / h.

The resulting water is subjected to desalination and reverse osmosis treatment on a COM 3.0-16 installation, operating on the principle of reverse osmosis or nanofiltration (depending on the composition of the source water and the requirements for desalinated water, a certain type of membrane is selected) - separation of fresh water from mineralized water through a semipermeable membrane under pressure , which for given conditions and the type of membrane is in the range of 10-15 kg / cm ² . At this pressure, pure water molecules pass through the pores of the synthetic composite membranes and the hydrated salt-forming ions are retained: HCO ₃ ^- , SO ₄ ^2- , Cl ^- , Ca ²⁺ , Mg ²⁺ , Na ⁺ , K ⁺ , Fe ²⁺ , Cu ^{2 +} , F ^- , as well as tannins and the entire spectrum of organic compounds and colloids, which are much larger. The resulting purified water is not only freed from the ions of dissolved salts, but also is sterile, since the membranes retain bacteria and viruses.

The useful productivity of the plant for treated water is 3.0 - 4.5 m ³ / h depending on the ionic composition and temperature of the source water.

 After reverse osmosis purification, the water is acidified to pH 4.5-5.5.

 The purified acidified water is then fed to a dolomite filter.

 The filter is a cylindrical tank made of stainless steel 12X12H10T, with tubular drainage devices. The upper drainage device is equipped with a mesh, which prevents the removal of the load from the filter when it is purged, flushed.

At the bottom of the filter there is a hatch designed for unloading the load. The filter is loaded through an opening in the filter cover with the upper drainage removed. Overall dimensions of the filter: diameter 800 mm, height 2000 mm. Filter loading includes:
Quartz crushed granular NFQ with a particle size of 8 mm, 5 mm, 3 mm.

 Partially calcined dolomite brand - Semidol K2.

The mineralogical composition of Semidol K2 is represented by the following compounds: CaCO ₃ - 68.5 vol.%, Free CaO 1.0 vol.%, MgCO ₃ - 5.6 vol.%, Free MgO - 25.1 vol.%, Trace elements - the rest .

 The ratio between the quartz substrate and the dolomite layer is 1: 50. The maximum possible filter load with Semidol K2 is 2000 kg.

 Demineralized water is supplied to the filter from above through an adjustment valve.

 Mineralized water is drawn from the bottom of the filter.

 The table shows examples of the production of water of different composition.

By changing the volume of the dolomite load, the pH of the water and the rate of transmission of water through the filter load, it is possible to obtain water of the desired composition by the content of calcium and magnesium. In addition, having obtained water with a high content of calcium and magnesium and diluting it with water after a reverse osmosis filter, one can obtain the desired salinity in the market water. The content of sodium chloride and sulfate in the resulting water is not more than 10 mg / dm ³ , while the norm in drinking water of the content of these compounds is 350-500 mg / dm ³ .

 Examples of the filter are shown in the table.

Claims (2)

1. The method of preparation of drinking mineralized water, including rough cleaning of tap water, reverse osmosis treatment and subsequent mineralization, characterized in that the water after reverse osmosis treatment is acidified to pH 4.5 - 5.5, and then passed at a speed of 1.2 - 7 m ³ / h through a two-layer filter charge consisting of a substrate based on crushed quartz and a layer of partially calcined dolomite with a grain size of 2.5 - 4.5 mm, while water is saturated with bicarbonates while passing through the filter charge aluminum and magnesium to mineralization of 50 - 1500 mg / l. 2. The method according to claim 1, characterized in that partially calcined dolomite of mineralogical composition is used, vol.%: CaCO ₃ - 60.0 - 70.0; free CaO - 0.8 - 1.5; MgCO ₃ - 5.0 - 6.0; free MgO - 20.0 - 30.0, trace elements - the rest.

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