RU2027677C1 - Method to purify water and a device to implement it - Google Patents

Abstract

FIELD: water purification from impurities of organic nature, heavy metals and microorganisms. SUBSTANCE: device is made in the form of cylindrical shell, diameter of which is equal to or more than its height. The shell has conical lid and bottom equipped proper outlet and inlet nozzles for water. Internal space of the shell is subdivided along its height by three partitions into zones. These partitions have perforation gradually distributed along all area, with upper and lower partitions having holes in their periphery. Middle partition has one central hole of such dimensions, that ratio of area of additional holes to the rest perforation area is (1 - 9): 1 for each partition. A layer of phosphate of cellulose ether with static exchange capacity volume exceeding 2 mg- eq/g is placed over upper and lower partitions, and over and under middle partition. The remainder space inside shell is filled with mixture of carboxyl bearing cationite with static exchange capacity exceeding 10 mg-eq/g, anionite with static exchange capacity exceeding 1 mg-eq/g, and activated charcoal with volumetric ratio between above three sorbents equal to 1:(1 - 5):(4 - 10), and with ratio of phosphate of cellulose ether volume to other sorbents equal to 1:(2 - 5). Device comprises cylindrical body with a lid and conical bottom. Inlet and outlet branch pipes are connected to the lid and bottom. Device comprises also horizontal partitions with holes of different diameters made in them, and fiber ionexchanging material layers located at lower and upper and at both sides of middle partition, and grained sorbent located between above layers. EFFECT: purified water. 3 cl, 1 dwg, 2 tbl

Description

 The invention relates to methods for purifying water from organic contaminants, such as phenols, insecticides, surfactants and other inorganic substances, such as ammonia, hydrogen sulfide, heavy metals (lead, chromate, cadmium, copper, nickel, mercury, manganese, tin and others), as well as microorganisms, in particular to methods for producing drinking water or deionized water from a contaminated fresh source by passing it through ion exchangers and / or activated carbon, and / or mixtures thereof. The invention also relates to devices (filters) for water purification for use in everyday life as a nozzle on a water tap or other pipe.

 A known method of purification of tap water, in which water is passed through a mixture of activated carbon and ion exchanger in the ratio (1-3): 1. In the method, the sorption of heavy metals with respect to pure ionite is increased by 20-30% [1].

 The disadvantage of this method is the inefficient use of sorbents due to uneven flows, as well as the use of sulfonic acid cation exchange resin with a very small static exchange capacity (1.8) for sorption of heavy metals, for this reason, an increase in capacity of 20-30% gives a slight overall effect.

 As a prototype of the selected method of processing water using a fibrous filter material [2].

 However, this method has a low degree of purification by harmful substances (below the maximum permissible concentration when the content of harmful substances in the source water is about 10 maximum concentration limits) and is not able to maintain the cleaning depth during volley breakthroughs of high concentrations of harmful substances (100-200 maximum concentration limits).

 A device for water purification in everyday life, comprising a cylindrical body with a lid and a bottom, supply and outlet pipes, installed in the housing upper, lower and middle horizontal perforated partitions and a granular absorber located between them [3].

This device, adopted as a prototype, has the following disadvantages:
short life due to uneven movement of water through a layer of sorbents;
washing out of coal dust at each start-up in a bottom-up mode and even greater reduction in operating life due to unproductive discharge of treated water with coal dust into the sewer;
inability to clear volley breakthroughs of water with a high content of harmful substances. This is due to the fact that the kinetics of sorption on coal and ion exchangers, both granular and fibrous, synthetic and artificial, is such that with a filter mass of 0.3 - 0.4 kg, the speed of the purified water flow is 0.3 - 0.4 l / min is the limit at which it is possible to achieve a degree of purification of more than 70 - 80% if the MPC for a harmful substance is exceeded by 3 to 5 times. With a short-term excess of the MPC in purified water by 100 or more times, an excess of the content of harmful substances in the outgoing water is 10-50 times higher than the MPC value, which is associated with kinetic limitations in the properties of sorbents.

 The objective of the invention is to develop a method and device that allows you to create a compact device for water purification (weighing 0.3 - 0.4 kg) with a long service life (1 year) and a high degree of purification of harmful substances (below the MPC with the content of harmful substances in the original water about 10 maximum concentration limits), which can maintain the cleaning depth during salvo breakthroughs of high concentrations of harmful substances (100 - 200 maximum concentration limits).

 According to the proposed method, water is passed through five layers of sorbents sequentially along the flow of water, the odd layers being an ion-exchange fibrous material based on cotton cellulose having strongly acid and medium acid cation-exchange groups in a ratio of 1: 1 and a static exchange capacity of at least 2 mg eq / d and having complexing properties with respect to heavy metals, and even layers are a mixture of a weakly acid complexing carboxylic cation exchanger having a static exchange capacity not less than 10 mg · equiv / g of anion exchange resin having a static exchange capacity of not less than 1 mg.eq / g and activated carbon in a volume ratio of 1: (1-5) :( 4-10), with a volume ratio of odd layers to even layers 1: (2-5).

 The device provides the most efficient use of sorbents due to the fact that it organizes the path of water through sorbents 3-4 times longer than the height of the filter, and organizes moderate water flows through the stagnant zones of the filter. This is achieved by the fact that the inner space of the filter shell is divided by three horizontal partitions having perforation evenly distributed on the surface of the partition wall and reaching the walls of the shell with the formation of four zones, the upper and lower partitions being provided with holes passing along the periphery of the partition walls evenly distributed evenly in addition, the middle partition is equipped with an additional central hole of such dimensions that for all three partitions the ratio the ratio between the total area of peripheral or central holes on one side and the total area of all other uniformly distributed perforations is (1–9): 1. In this case, phosphoric ether of cellulose is taken as odd layers, the 1st and 5th layers are respectively on the upper and lower partitions, and the 3rd layer is on top and bottom of the middle partition and is adjacent to it.

 Even layers include a mixture of granular sorbents with the highest possible ion exchange capacity in three classes of harmful substances (organic, cationogenic and anionic) with kinetic properties, i.e. the rate of sorption of harmful substances by sorbents, the same as in analogues and prototype. Odd layers contain a sorbent with extremely high kinetic properties (100 times higher than sorbents of even layers) and a high degree of sorption from low concentrations (about 1-2 MPC). Thus, the 1st layer, due to its high kinetic properties, removes volley breakthroughs of high concentrations of harmful substances, ensuring the uniform operation of high-capacity 2nd and 4th layers, the 5th layer, having a high degree of sorption from low concentrations, gets traces of harmful substances after the work of the 2nd and 4th layers, providing a greater depth of water purification than the prototype, the 3rd layer, in addition to the separation function, creates two stages that provide a long service life - an even layer with a large cleaning depth (3rd and 5th layers).

 The presence in the odd layers, firstly, of an ion exchanger complexing heavy metals, and, secondly, of an ion exchanger carrying strong and medium acid groups, and in even layers of an ion exchanger with weak acid groups, complexing heavy metals by carboxyl groups, allows the filter to be removed from water, all types of heavy metal ions having both different acidic properties and various affinity for complex formation, as well as almost all types of contaminated and polar molecules and ions of other organic and inorganic substances.

 The presence in the even layers of the mixture of anion exchange resin and activated carbon ensures the removal of the remaining negatively charged organic and inorganic ions from the water, as well as uncharged organic molecules from the water; in addition, carbon sorb pathogenic microorganisms of various classes.

 The design of the internal device is such that, firstly, it provides separation of the layers, and secondly, elongation of the water flow path along the sorbent, elimination of stagnant zones, and therefore, an increase in the filter service life by reducing losses due to uneven flow through the sorbent layers .

 The drawing shows a longitudinal section of a device for purifying drinking water.

 The device consists of a cylindrical body 1, a cover 2 with a supply pipe 3, a conical bottom 4 with a discharge pipe 5, upper 6, middle 7 and lower 8 horizontal perforated partitions. On the periphery of the lower and upper partitions and in the center of the middle hole 9 are made larger than all the other holes 10. It was experimentally established that for the best operation of the device, the ratio of the sum of the areas of the larger holes and the sum of the areas of the remaining holes should be (1-9): 1.

 On the partitions 6 and 8 and on both sides of the partition 7 there are layers 11 of ion-exchange fibrous material, for example, based on cellulose, and between these layers there is a granular absorber 12, made in the form of a mixture of a weakly acid complexing carboxylic cation exchanger, anion exchange resin and activated carbon.

 The device operates as follows.

 Water from a source of contaminated fresh water, for example from a faucet (not shown), through a coupling made, for example, in the form of a rubber pipe (not shown), enters the inlet pipe, passes through the first layer of the lower and upper partitions so that a large part of the flow passes through the peripheral holes 9, and a smaller part of the flow passes through perforations in the upper partition. Thus, elongation of the flow path and uniform distribution of the flow over the entire layer of the sorbent mixture are achieved. This is also carried out using the middle partition 7, through which water enters in a large stream through the central hole 9 and a smaller stream through the perforation, while the water passes through the layers 11 adjacent to the bottom and top to the middle partition. Further, the main water flow diverges in the radial direction from the central hole of the middle partition to the peripheral holes 10 of the lower partition 8, passing through the thickness of the absorber layer 12 from a mixture of sorbents and the last layer 11, while the uniform distribution of the flow across the thickness of the sorbents provides holes 10 of the middle and lower partitions . Next, the water flows freely in the bottom 4 and through the outlet pipe 5 is poured out.

PRI me R 1. The filter shown in the drawing, the diameter and height of the shell 100 and 70 mm, respectively, contains in the 1st, 3rd and 5th layers 80 cm ³ (in total) FEC with SOE = 2.1 mg · equiv / g, in the 2nd and 4th layers 30 cm ^{3 of} KB-4 cation exchanger and СОЕ = 10.5 mg eq / g, 60 cm ^{3 of} AB-17x8-h anion exchanger with СОЕ = 1.1 mg eq / g and 120 cm ^{3 of} activated carbon GS-01, as a result, the volume ratio of carboxyl cation exchange resin to anion exchange resin and activated carbon is 1: 2: 4, and the ratio of the 1,3,5th layers to the 2nd and 4th layers is 1: 2,6 . The partitions had a hole area of 1.77 cm ² and a perforation area of 0.8 cm ² , the ratio of hole area to perforation area was 2.2: 1. Tap water containing lead, cadmium, chromium was passed through a filter at a speed of 300 ml / min. (III), chromium (IV) in an amount of 1 mg / l, phenol in an amount of 0.05 mg / l, 3.7 cm ^{3 of} water were passed and analyzed. The purified water contained lead 0.1 mg / L, cadmium 0.03 mg / L, chromium (III) 0.02 mg / L, chromium (IV) 0.01 mg / L, phenol 0.0005 mg / L. Thus, water is completely purified to the maximum permissible concentration in the amount of annual consumption provided that the water consumption is 10 l / day. In addition, the water is effectively purified from microorganisms.

PRI me R 2. Use filters, as in example 1, with the difference that:
2.1. Carboxyl cation exchange resin used:
KRK - 1 - 20 with SOE = 8 mg eq / g FEC with SOE = 1.5 mg eq / g, anion exchange resin with SOE = 0.6 mg eq / g.

2.2. The perforation area is 2 cm ² (0.9: 1 ratio).

2.3. The perforation area of 0.12 cm ² (ratio 15: 1).

In case 2.1, 2.9 m ^{3 of} water was purified to the same concentration values; in case of 2.3, 2.5 m ^{3 of} water, which is associated in 2.1 with a lack of sorbent capacity, and in 2.3 with the presence of stagnant zones and incomplete use of sorbents.

In case 2.2, 3.4 m ^{3 of} water was purified to concentrations of lead of 0.15 mg / l, cadmium 0.38 mg / l, chromium (III) 0.03 mg / l, chromium (IV) 0.02 mg / l phenol 0.001 mg / L. The deterioration of cleaning is due to the fact that a part of the main flow, which goes a long way, is reduced: most of the flow through the perforations passes a direct path through the filter.

PRI me R 3. Use a filter, as in example 1, with the difference that:
3.1 instead of five layers, only two layers were taken, combining 1.3 and 5, as well as 2 and 4;
3.2 the volume ratio of the odd (1,3,5) layers and the even (2,4) layers was 1: 1;
3.3 the volumetric ratio of odd to even layers was taken 1: 6;
3.4 instead of cotton cellulose-based PECs, viscose-based PECs were taken.

 The experiments were carried out with volley breakthrough of high concentrations of substances - 20 l of tap water with a concentration of lead, cadmium, chromium (III) and chromium (IV) 20 mg / l, phenol 0.5 mg / l were passed. In purified water, harmful substances were analyzed. The results of the analysis are given in table. 1 (for clarity, it presents the data of experiment 1).

 As can be seen from example 3, a change in the ratio of odd to even layers or a change in their order leads to a decrease in the cleaning depth by several times (3 times for lead). The same effect is observed when replacing cotton cellulose-based PECs with viscose-based PECs or other fibrous cation exchangers, for example fibrous polypropylene with grafted polyacrylic acid or fibrous VION KN-1, which is saponified polyacrylonitrile.

 The decrease in cleaning depth in examples 3.1-3.4 in comparison with example 1 is due to: in 3.1, the absence of layers 3 and 5 with getting already reduced concentrations of harmful substances after passing layers 2 and 4 with high-capacity sorbents; 3.2 with a decrease in the content in the filter layer of high-capacity sorbents; 3.3, with a decrease in the content of FEC, which quickly removes high concentrations of harmful substances and provides favorable working conditions for layers 2 and 4: 3.4, with the fact that any other fibrous sorbents have worse sorption kinetics than FEC based on cotton cellulose.

 PRI me R 4 (comparative).

Claims (4)

 METHOD FOR WATER CLEANING AND DEVICE FOR ITS IMPLEMENTATION.  1. A method of purifying water, including passing it through a layer of fibrous filtering ion-exchange material and / or activated carbon, characterized in that the water is sequentially passed through five layers of filtering material, using phosphoric ether as an ion-exchange fibrous material in odd-numbered layers cellulose, and in even-numbered layers - a mixture of carboxylic cation exchange resin with a static exchange capacity (SOE) ≥ 10 mg eq / g, annionite with a SOE value ≥ 1 mg eq / g and th e coal, taken in a volume ratio of 1: (1 - 5): (4 - 10), respectively, wherein the volume ratio of the sum odd layers to the total volume of even layers is 1: (2 - 5).  2. A device for water purification, comprising a cylindrical body with a lid and a bottom, supply and outlet pipes, upper, lower and middle horizontal perforated partitions installed in the housing and a granular absorber located between them, characterized in that it is provided located on the upper, under the lower and on both sides of the middle partition with layers of fibrous ion-exchange material, the ratio of the sum of the areas of the holes located on the periphery of the upper and lower partitions and in the center of the middle, and the sum of the areas of the remaining holes is made 1 - 9: 1.  3. The device according to claim 2, characterized in that the bottom is tapered and a discharge pipe is attached to it, and the supply pipe is attached to the cover.

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