RU2173577C1 - Adsorption product for treatment of water - Google Patents

Abstract

FIELD: water treatment. SUBSTANCE: product consists of shell and silicon dioxide filler, namely zeolite mineral with partially water-proofed surface, which is composed of following fractions: 0.25-0.5 mm, 0.5-1.5 mm, 1.5-4.0 mm, surface of fraction 0.5-1.5 mm being waterproof. Shell is made from waterproof material and is provided with self- opening valves. EFFECT: increased sorption capacity for organic and mineral impurities. 2 cl

Description

 The invention relates to the field of inorganic chemistry, and more specifically to methods for treating water in ponds and other artificial reservoirs, as well as in natural lakes, rivers, etc.

 A large number of adsorbents suitable for the purification of water produced in powder or granular form are known. However, they are not suitable for cleaning large water areas due to the inconvenience of their storage and use. Often during storage, the activity of sorbents is lost, and after their use a lot of work is required to collect and dispose of them. In this regard, when cleaning natural reservoirs, the problem of developing absorbent products devoid of the disadvantages associated with powdery and granular sorbents becomes relevant.

 An absorbent article is known comprising a shell of wool felt and a core of crushed dried bark (RU, N 2115468 B 01 J 20/24, 1998).

 A known product has a high oil absorption, but other types of pollution remain in the water.

 A layered adsorbent article is known containing a layer of inorganic sorbent based on silicon dioxide and a plasticizer layer for removing hydrocarbons (FR, N 2645047, B 01 J 20/28, 1989).

 However, the implementation of the known product from two layers reduces the effectiveness of each layer.

 Known corrugated sheet of paper made of inorganic fiber containing zeolite and / or activated carbon and an inorganic binder (EP, N 0492879, B 01 J 20/28, 1992).

 Known sorbent effectively purifies gases, but in the aquatic environment has a low absorption capacity. A known method of cleaning the environment as a result of an uncontrolled spill of mineral oils and other petroleum products in water. Adsorbent is applied to the spilled material in an amount of 0.1-1.5 parts per one part of the oil product. The adsorbent particles are allowed to mix with the oil product and absorb it, after which the adsorbent saturated with the oil product is collected and removed, which is a low-density solid product with a non-oily and non-sticky surface floating in a pond (US, N 5104548, class C 02 F 1 / 28, publ. 92 g.).

 For cleaning aqueous media, an adsorbent containing clinoptilolite on a non-woven basis, impregnated with latex and formed by calendaring is more effective (RU, N 2094091, B 01 J 20/18, 1997).

 A disadvantage of the known adsorbent is the inconvenience of its use in open waters.

 The closest in technical essence and the achieved result is an absorbent product for removing contaminants from liquid media, which is a protective bag of non-woven material containing rice husk ash as a sorbent (US, N 4831010, B 01 J 20/10, 1989).

 The main component of rice husk ash is silicon dioxide, in addition, a small amount of carbon is present in the ash. The known sorbent has a satisfactory capacity for oil products, however, a high degree of purification is not achieved from inorganic impurities and pathogenic flora. In addition, through the said bags, the penetration of water in a natural way is difficult.

 The objective of the present invention is to develop an absorbent product, effectively absorbing both organic and inorganic pollution, suitable for use in natural reservoirs.

 The problem is solved by the described absorbent product for water treatment, containing a waterproof shell and a filler is a zeolite-containing rock with a partially hydrophobic surface, while the shell is equipped with self-opening valves. Preferably, the rock contains a filler of three fractions of the following particle size distribution 0.25-0.5 mm, 0.5-1.5 mm and 1.5-4.0 mm, while the surface of the fraction 0.25-0.5 mm is hydrophobic .

 It should be noted that hydrophobicity of zeolites can be imparted by any known method, including previously spent zeolites, for example, in the process of oil hydrocracking, as zeolites with a hydrophobic surface.

 The method of water purification by the claimed product is as follows. Zeolites are packed in waterproof mesh flat plastic bags with self-opening valves under pressure (five pieces with a diameter of 7 cm) on the bottom and neck. The shell has the shape of a rectangle, the filler is placed inside a relatively thin layer (10 - 15 cm). After opening the valves, they are placed directly in the reservoir vertically in several successively arranged rows across the main directions of water movement in the season. The location and depth of the adsorbent products is fixed by means of anchor devices. The amount of adsorbent introduced into the reservoir is 300 - 500 kg / ha. Products are kept in water from five days to two weeks (depending on the degree of contamination of the reservoir).

 Products can be located perpendicular to the flow of water, placed at an angle to the flow, they can be located on the same level, can be on different. Products can be staggered in relation to the flow or any other, which is selected depending on the object being cleaned.

 After the reduced content of pollutants is stably achieved in the reservoir, the absorbent article is removed from the water, and the zeolites are sent for regeneration.

 Example.

In May-July 2000, on the cascade of ponds near the Khimki reservoir, an “average” pond with a volume of 3600 m ³ was selected. The degree of water pollution in it (iron, alkali, discharge of oil products, fine suspensions of various mineral substances) is close to the average for Moscow ponds.

 In this pond was placed "dam" of the claimed absorbent products. The shells of the products are polypropylene, 63 by 94 cm in size. In them, valves with a diameter of 4 mm are made by hot "pressing". Their length is 80. Their width is 27. The number of valves is the same on both sides of the bag.

 For filling into the shells, a mixture of zeolite rocks (Bashkir deposit) of three fractions was used - 0.3 mm, 1.4 mm, 3.7 mm, fraction 03, mm was hydrophobized. All three fractions were mixed in equal proportions.

 The mixture was poured immediately before immersion in water (products were placed on wooden pallets, thirty pieces per pallet and were lowered into a pond with a truck crane). The pallets were loaded staggered diagonally in order to create an additional flow of water. 1.5 tons of zeolites were placed on one pallet. A total of 17 pallets with a total weight of 25.5 tons were loaded into the pond.

 All pallets were laid to the bottom in such a way that the absorbent products from the last pallet slightly rose above the surface of the water. Forty-eight hours later, all products on pallets were raised to the surface.

According to preliminary estimates, water leaked through the items during their stay in the pond. From the difference in day and night temperatures, the flow rate of water through the product was about 75 m ³ per hour. As a result, during the two days of the “zeolite sieve” stay in the pond, practically all the water mass contained in the basin of the reservoir flowed through it.

As a result, after analyzing water samples taken from the pond after removing the absorbent product, it turned out that in 48 hours the volume (by weight) of harmful substances decreased by:
- iron by 45%;
- oxides of chromium and manganese by 78%;
- petroleum products by 62%;
- mineral suspensions of various origin by 37%,
- biologically harmful organisms (pathogenic flora) by 23%.

 Having calculated these indicators using the “growing Gaussian” formula, we can conclude that increasing the exposure of products in water by a factor of two (up to four days) will make it possible to purify water by 70 - 78% of most harmful indicators (except for pathogenic fauna, which can be controlled with special chlorine-containing preparations).

 Thus, the experiment on cleaning one "middle" pond with the claimed product provided positive results. You can predict a similar effect when cleaning any other artificial or natural reservoirs with a slowed flow of water.

Claims (2)

 1. An absorbent product for water treatment containing a shell and a filler based on silicon dioxide, characterized in that as a filler it contains zeolite rock with a partially hydrophobized surface, and the shell is made of a waterproof material and equipped with self-opening valves.  2. The absorbent product according to claim 1, characterized in that the filler contains a rock of three fractions: 0.25 - 0.5 mm, 0.5 - 1.5 mm, 1.5 - 4.0 mm, while the surface of the fraction 0.25 - 0.5 mm hydrophobic.