RU2143947C1 - Sorbent for cleaning natural water and soil from oil pollutants - Google Patents

Abstract

FIELD: removal of oil pollution. SUBSTANCE: sorbent contains aluminosilicate carrier with immobilized microorganism Rhodococcus SP strain No 30 and phosphorus- and nitrogen-containing salts. EFFECT: enhanced cleaning efficiency and completely safe environmental condition. 2 cl, 3 tbl

Description

 The invention relates to the field of ecology, in particular to compositions of sorbents used for the purification of natural environments.

 Natural systems have encountered evolutionary contaminants such as petroleum hydrocarbons. Despite this, until the beginning of the 20th century, there was no global degradation of natural systems under the influence of these contaminants. The removal of these pollutants from the system was based on their sorption by natural sorption materials and their transfer, for example, from the aqueous phase into a precipitate, where they underwent further evolution. Numerous types of bacteria also took an active part in the decomposition of petroleum hydrocarbons. These and some other features of natural self-cleaning processes formed the basis of the technology developed in the scope of this invention.

 The prior art purification methods using the advantages of both sorption and biological treatment.

 A known method, for example, is the purification of water from oil pollution using a sorbent based on hydrophobized silica gel immobilized by the CANDIDA INTERMEDIA culture (SU 255138, C 02 F 3/34, 1970).

Known sorbent for removing oil stains from the surface, which includes aluminosilicate carriers selected from the series: kaolin, perlite, zeolite, etc., oil-absorbing microorganisms selected from the series: PSEUDOMONAS AERGIHOSA, METHANOMONAS METHARIA, BASTERIUM ALIPHATICUMOTOLUMOTOLUMO BILES, both other and biogenic substances selected from the series: NH ₄ Cl, (NH ₄ ) PO ₄ , CaCl ₂ and others (US 3843517, C 02 B 9/02, 1974).

 Also known is a sorbent for the absorption of oil pollution, containing carboxymethylated yeast, higher fatty acids, aluminum salts, alkaline earth and transition metals and a carrier (JP 56-9393, C 02 F 1/00, 1981).

 A sorbent and a method for its preparation are known, according to which activated carbon is introduced into the polymer melt, an article is formed and it is immobilized with microorganisms of activated sludge (RU 2023685, 1994).

 The disadvantages of the above sorbents is that they contain technogenic components, which complicates and increases the cost of the cleaning process, as well as the risk of secondary pollution.

 Sorbents containing mainly natural substances are more promising.

 A known sorbent containing a neutral porous carrier, ammonium nitrate, diammonium phosphate, potassium chloride, magnesium chloride and a mixture of active oil-absorbing cultures of microorganisms isolated from a natural community in a polluted environment (RU 2057724, 1996).

 Among the various strains of microorganisms used in the technology for cleaning soil, sewage and natural waters from organic, including oil pollution, various types of bacterial culture strains RHODOCOCEUS (RU 2019527, 1994), (RU 2039714, 1995), (RU 2090697) are very popular. , 1997).

 At the same time, to increase the efficiency of bacterial reproduction and growth, and, accordingly, to accelerate the biodegradation of petroleum hydrocarbons, this culture is introduced together with sources of nitrogen and phosphorus.

A known sorbent containing a porous carrier (talc, diatomite, kaolin), strain PSEUDOMONAS PUTIDA, KNO ₃ NH ₄ Cl, NH ₄ NO ₃ , NH ₄ H ₂ PO ₄ (WO, 87107316, 1987).

 A disadvantage of the known sorbent is the high consumption of reagents. To reduce the consumption of reagents, sorbents containing various types of microorganisms RHODOCOCCUS on carriers have been proposed.

For example, the Naftox sorbent is known, which contains peat, normal C ₁₂ -C ₁₈ paraffin, oxalic acid ammonia, water, and RHODOCOCCUS SP (RU 2053205, 1996).

 However, the effectiveness of this sorbent is low. So for five days of cleaning the surface was only about 60%.

 The closest in technical essence and the achieved result is a sorbent for cleaning oil systems contaminated with oil and oil products, containing an inert porous carrier based on aluminosilicate raw materials (clay) 90-99.99% and a consortium of microorganisms-strains RHODOCOCCUS SP 367-2, RHODOCOCCUS MARIS 367 -5, RHODOCOCCUS ECUGTHROPOLIS 367-6, PSEUDOMONAS STRUTRERI 367-1, YARROWIAIPOLYTICA 367-3 (RU 2104249, 1998).

 The above sorbent provides a high degree of purification and good performance of the cleaning process, however, the clay-based carrier does not have a developed pore surface, which reduces its effectiveness.

 The objective of the present invention is to provide a sorbent based on natural components with high biodegradation efficiency of oil, including at low temperatures, and complete environmental safety.

The problem is solved by the described sorbent of the following composition, wt.%:
Microorganisms RHODOCOCCUS SP. strain N 30 - 4-5
Superphosphate - 0.8-1.2
Ammonium nitrate - 0.8-1.2
Aluminosilicate carrier selected from the series: heat-treated perlite or vermiculite - Else
It is preferable to use perlite or vermiculite, containing in its composition, wt.%:
Al ₂ O ₃ - 13-14
MgO - 13-14
K ₂ O + Na ₂ O - 2-6
CaO - 1-3
H ₂ O - 2-4
SiO ₂ - Else
The above composition of the sorbent is selected experimentally, taking into account maximum efficiency, durable immobilization of microorganisms on a carrier and low cost.

The characteristics of the immobilized culture are as follows:
The strain referred to as N30 (Hygienic certificate N150 of 02.16.96).

Sources of separation are the Barents Sea. Coordinates: 74 ^o 20 'north latitude, 20 ^o 30' east longitude; Horizon - 1 m.

Morphological and cultural features: colonies are bright yellow, shiny, mucous, homogeneous
Growth temperature 20-24 ^o C
Growth time - 3 days.

According to toxicological indicators, the strain does not have local irritant effect at a dose of 10 ¹¹ microbial bodies, skin-resisitive and allergic action at a dose of 10 ⁷ microbial bodies.

 Sorbent is prepared as follows. Perlite or vermiculite is crushed to granules with a dispersion of 3-7 mm, swell in a thermal furnace, cooled to room temperature, then microorganisms are immobilized on the surface in the presence of ammonium nitrate and superphosphate. The process is conducted in a conventional mixer for bulk materials with a rotating body, such as a concrete mixer. The method is simple to execute.

 The invention is illustrated by examples.

Example 1
Take a sorbent with a content, wt.% - composition A:
Microorganisms - 5
Superphosphate - 0.8
Ammonium nitrate - 1.2
Aluminosilicate carrier (1) -perlite - the rest
composition
Al ₂ O ₃ - 12
MgO - 13
K ₂ O + Na ₂ O - 2
CaO - 1
H ₂ O - 2
SiO ₂ - Else
1 kg of oil is poured into a container with a diameter of 1 m and a height of 1.5 m filled with water. Then, 1 kg of sorbent is added to the container. The temperature of the water in the tank is 20 ^o C. Measure the time of destruction of the film of oil. For comparison, a well-known sorbent made according to the invention of the prototype is simultaneously tested under the same conditions. The compositions of examples 1-6 are shown in table 1, 2. The results of comparative tests are given in table 3.

 From the results presented in table 3, it can be seen that the sorbent according to this invention is 3-5 times more effective than the known one. Moreover, the effectiveness of the sorbent increases with decreasing temperature of the medium in which it is operated, since its performance indicators practically do not depend on this temperature, while in a known one it deteriorates.

The characteristics of the obtained sorbent, called "Muscat", are as follows: appearance - solid granules 3-5 mm in diameter, color - gray, pH value of 1% aqueous suspension 6-8;
Flotation ability of 60-90% of the mass;
Volumetric weight (kg / m3) - 140-160;
Decrease in interfacial tension water-oil (erg / cm) - 1,5-2
Oil absorption from the water surface (kg of oil / kg of sorbent) - 1.8-3.4
Relative hydrophobicity (%) - 30-90
Swimming ability - 25-75
Bio-destructive ability in sea water (kg of oil / kg of sorbent for 5-7 days) - 1.5-3.2
Thus, it was possible to obtain a sorbent, after the application of which in the natural system there are no foreign ingredients of anthropogenic origin.

 Practical testing of the obtained sorbent was carried out during the liquidation of the results of a spill of diesel fuel and fuel oil on the soil, the liquidation of an emergency oil spill in the Gulf of Finland and Lake Ladoga, etc. As the results of testing showed, the described biosorbent has a cascading effect.

 1. The release of 80-90% of the water surface from oil, the retention of oil from spreading, the restoration of oxygen balance. This is achieved in the first 10-30 minutes of application, which makes it possible to start the basic natural cleaning mechanisms, which substantially depend on the restoration of the oxygen balance blocked by the oil layer.

 2. Sorption of petroleum products in 1-6 hours, depending on the amount and type of oil.

3. Activation of natural biological and physico-chemical self-purification mechanisms and microbiological destruction of hydrocarbons of petroleum origin. Moreover, more than 85% of the main fractions of oil are removed from the ecosystem at temperatures from -1 to +50 ^o C for a time from 2 days to 4 weeks.

The amount of sorbent used depends on the nature of the contamination and temperature; on average, 50 to 150 g per 1 m ^{2 of} contaminated surface are used. One ton of sorbent is enough to clean the system from 8-12 tons of oil products.

 The use of the sorbent according to the invention will significantly increase the efficiency of cleaning the environment from unexpected spills of oil products and improve the environmental situation as a whole.

Claims (1)

1. Sorbent for the purification of natural water and soil from oil pollution "Moskat" containing aluminosilicate carrier and microorganisms of the genus RHODOCOCCUS SP. , characterized in that as a carrier it contains heat-treated perlite or vermiculite, additionally contains ammonium nitrate and superphosphate, as microorganisms RHODOCOCCUS SP. strain N 30 with the following components, wt.%:
Microorganisms RHODOCOCCUS SP. strain N 30 - 4 - 5
Superphosphate - 0.8 - 1.2
Ammonium nitrate - 0.8 - 1.2
Heat-treated Perlite or Vermiculite - Else
2. The sorbent according to claim 1, characterized in that it contains perlite or vermiculite, having in the composition, wt.%:
Al ₂ O ₃ - 12 - 15
MgO - 13 - 14
K ₂ O + Na ₂ O - 2 - 6
CaO - 1 - 3
H ₂ O - 2 - 4
SiO ₂ - Else

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