RU2375315C2 - Method of purifying coastal water from film-type and dispersed petroleum products in water surface layer - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves placing a filter in the contamination zone, where the filter is filled with sorbing medium, populated with oil oxidising microorganisms. The sorbing medium used is floating agal plantation, the base of which is a system of joined synthetic ropes, planted with laminaria and focus algae. Laminaria is placed deep in the water on vertical ropes of length 5 m, and focus algae are placed on horizontal ropes in the surface layer.

EFFECT: invention increases rate of converting oil contaminates dispersed on the sea surface to products which are safe for marine biota, increases service life of the proposed protective structure due to processes of natural development and restoration of association of algae and oil oxidising bacteria.

8 tbl

Description

The invention relates to the field of environmental engineering and relates to a method for treating surface waters in coastal areas of the sea, bays and other areas of possible industrial pollution by oil and oil products (NP) by biological treatment of water using algae in combination with hydrocarbon-oxidizing (HC-oxidizing) microorganisms.

The essence of the invention boils down to the development of purification technology, including the creation of plantations of macrophyte algae inhabited by microorganisms capable of decomposing hydrocarbon components of oil and oil to substances that are safe for the environment and benthos.

The need to develop such methods is dictated by the fact that the coastal waters of Russia are increasingly becoming a place of production, transshipment, processing, as well as transportation of gas condensate, oil and oil products. This leads to increased pollution of coastal waters - breeding zones of many species of fish, invertebrates, algae, plankton and birds exposed to relevant pollutants.

Of particular interest are the seas of the Arctic shelf. The main sources of pollution here are maritime transport, the removal of hydrocarbons by rivers, the exploitation of offshore drilling platforms, the adsorption of hydrocarbons by the water surface and ice from the atmosphere, and the self-cleaning of the Arctic seas from hydrocarbons occurs 10-15 times slower than mid-latitude seas [1].

An analysis of current levels of water pollution in the coastal zone of the Russian sector of the Arctic [2] showed that in many areas the content of petroleum hydrocarbons in the water corresponds to the maximum permissible concentration (MPC) established by existing standards. This indicates that the processes of natural cleansing from such contaminants during the observation period were more effective than the processes of their accumulation. These data relate mainly to areas with intensive water exchange.

The development and implementation of the proposed technology is recommended for various climatic zones, but for the northern regions, where the period of natural decomposition of surface NPs due to natural conditions is significantly shorter, this is most relevant. The threat of increased pollution of coastal waters exists, for example, in the Barents Sea, where it is planned not only to develop the Shtokman gas condensate field, but also to build a gas condensate processing plant and powerful refueling fuel complexes on the Kola Peninsula coast. A similar danger is currently threatening the cleanest and most fertile waters of the Sea of Okhotsk off the coast of Western Kamchatka, where it is planned to conduct exploratory drilling for oil and gas. The experience of carrying out such work off the eastern coast of Sakhalin Island shows that the habitats of crab, scallop and sea urchin were seriously affected by the effects of pollution associated with the development and operation of wells. Details of the impact of offshore hydrocarbon production on biota are considered in [3].

A generalization of the results of observations and experiments performed by different researchers allows us to approximately estimate the contribution of individual factors to self-cleaning processes as follows: evaporation - 50-60%, oxidation - 15-35%, biodegradation - 10-20%. It should be borne in mind that in winter, self-cleaning efficiency decreases by about 3 times compared with summer. This happens mainly due to a decrease in the intensity of the first two factors.

However, one cannot rely on natural self-purification processes, since any natural system can withstand only a certain level of external loads, including anthropogenic pollution by hydrocarbons. An overestimation of the load limit on the medium in the case of, for example, a large-scale oil spill as a result of a tanker or pipeline accident, can bring the natural system of an entire region out of equilibrium and lead to severe environmental consequences. No less dangerous is the constant flow of NP to the bays, in the waters of which the ports and moorings of shipbuilding, ship repair and ship-breaking enterprises are located. Due to the constant technological leaks of the NP, the effects of hydrocarbons, as well as their impurities on the biota in such bays are amplified, leading to complete degradation without special cleaning measures.

In northern latitudes, low temperatures, frequent storms and seasonal ice regimes significantly limit the use of traditional methods of combating oil and oil pollution, such as mechanical collection, burning, etc. The use of chemical reagents here contributes to the degradation of natural systems more than in warm seas. A promising direction in the fight against oil pollution of coastal waters is the use of biotechnologies to increase the contribution of biodegradation to water purification processes, especially since the latter in winter, in terms of self-purification performance, becomes comparable with evaporation.

The study of patent literature allowed us to identify three main areas in the development of biotechnological methods of combating oil pollution: sorption, microbiological and direct stimulation of natural self-cleaning reactions. Currently, in the practice of water treatment, the greatest efficiency is achieved by the simultaneous use of sorption and microbiological methods. This combined method is called biosorption. Sorbent (powder, foamed, granular, fibrous, etc.) here plays the role of a carrier substrate for microorganisms and must have a developed surface. If in the process of purely microbiological water purification the non-oxidizable components of the NP are practically not removed, then the combination with sorption makes it possible to significantly increase the overall degree of purification.

As an analogue of the invention, it is possible to consider, for example, the use of a biosorbent obtained by the method described in the RF application for an invention [4]. The method involves mixing a porous heat-treated aluminosilicate as a carrier with a nutrient aqueous medium and hydrocarbon-oxidizing microorganisms. The disadvantages of the method include the relatively short “life” of the sorbent during storage, requiring periodic replacement.

Compositions containing preparations of lyophilically dried cultures of indigenous microorganisms consuming certain hydrocarbons adsorbed on a porous carrier are more effective. In this regard, another patent can be considered a patent of the Russian Federation [5]. Here, the biosorbent contains a carrier substance, a microorganism growth factor substance, and a biomass of hydrocarbon-oxidizing microorganisms. The main component of the carrier substance is a composition of Ca-alginate gel and n-alkanes (C14-C16). The composition of the biosorbent provides an increase in the density of microorganisms directly in the carrier zone adjacent to the interface between the NP and the medium being cleaned. Biosorbent is applied to the contaminated area, it is activated by the action of water, and microorganisms are included in the processing of hydrocarbons.

As in the previous method, such a biological product, not being limited from spreading on the surface of the water under the influence of wind and tidal currents, leaves the treated area, which reduces the cleaning efficiency and leads to a significant increase in the need for preparations. The same is true of purely microbiological methods, which, however, are effective for treating water in closed tanks, for example, holds of oil vessels or tanks for transportation of heavy oil fractions.

The above methods can be implemented using not only certain types of microorganisms, but also their superstrain, see, for example, the RF patent for the invention [6], which have the ability to oxidize a wide class of hydrocarbons and related compounds. To accelerate these processes on the water surface in stains of pollutants, it is proposed to use microorganisms in combination with surfactants that provide preliminary dispersion of contaminants. One of the drawbacks of such superstrain is the probability of conflict with natural associations of microorganisms [7].

To ensure long-term storage of biosorbents in granules, bacteria are most often in a state of suspended animation in the form of lyophilically or thermally dried substances that are activated when granules enter sea water, but they begin to “work” only in contact with oil and NP. Once not in sea water, but directly in the thickness of the hydrocarbon stain, part of the granules are enveloped with substances that counteract the ingress of water into their pores, which, in turn, inhibits the activation of bacteria and reduces the effectiveness of the use of appropriate drugs. In addition, it is necessary to take into account the high cost of obtaining and storing cultures of microorganisms and sorbents.

More traditional methods, for example, using booms, can be conditionally assigned to the analogues of the proposed solution, for example, see [1]. The devices described in this monograph allow in good weather (sea waves less than 2 points) to delay the spread of surface emissions of oil for a long time and collect them efficiently with the help of special collecting vessels, but only on condition that the spot thickness does not exceed the boom draft. Thus, boom barriers are able to block the spread of pollution only in a relatively thin layer of surface water, without preventing the pollutant from flowing through the booms or seeping under them in case of significant disturbance. At the same time, the pollutant dispersed under the influence of wind and wave processes is transferred to the water column.

The problems solved by the present invention are to expand the functionality of the purification system by combining both directions of combating film pollution of surface water with oil and oil, as well as eliminating the above disadvantages of analogues and increasing the life of the system by using a symbiotic association as a sorbing medium macrophyte algae — HC oxidizing microorganisms. ” In addition, the macrophytes used provide partial absorption of hydrocarbons by including them in the metabolism of the algae themselves, as well as a partial partial absorption of a number of toxic metals (TM) present in seawater [8], which is especially important for the industrial waste areas of the enterprises mentioned above.

The essence of the invention lies in the fact that this symbiotic association is formed in the form of a two-level floating biofilter, more precisely, a sanitary algal plantation (SVP), which plays the role of a biofilter, each of which levels is populated by its own species of macrophyte algae. The upper level is occupied by a surface layer with a thickness of about 0.3 m, which ensures the accumulation, partial assimilation of films of a hydrocarbon pollutant placed in it by algae and its oxidative destruction due to microorganisms that inhabit the boundary layer at the surfaces of algae. At the lower level there is a layer of algae that can occupy the water column to depths of 20–25 m and provide oxidative degradation of microorganisms dispersed in water and the sorption purification of water from HM.

The technical result of the invention is the purification of surface waters from hydrocarbon pollutants dispersed over the sea surface and in the surface waters by converting them into products that are harmless to marine biota. SVP can provide within 2-3 weeks a reduction in the level of pollution by HC-oxidizable components of NP from 10-20 MPC to the normal MPC (0.05 mg / l). In addition, the authors' experience shows that with proper operation, the life of the SVP due to the processes of natural development and restoration of the association of algae and hydrocarbon-oxidizing microorganisms in its modules can reach 6-8 years.

The obtained result is achieved by sharing the properties of floating SVP, which serves as an obstacle to the spread of the pollutant film under the influence of currents and a medium that removes and oxidizes hydrocarbons. This is due to the partial inclusion of NP hydrocarbons in the metabolism of a number of algae, as well as their microbiological degradation by creating conditions for life support in the plantation volume of the association “algae - HC-oxidizing microorganisms”. Of particular interest in the destruction of hydrocarbons is the fact that they dominate among other components of various types of oil, and their share varies from 50 to 98%.

In the volume of SVPs, a developed active surface from algae thalli is created - a concentrator of microorganisms, oxygen and a number of metabolites produced by algae are released into the environment, which are necessary to ensure the vital activity of microorganisms, as well as a decrease in the speed of movement of water masses, preventing the leaching of hydrocarbons and microorganisms beyond the SVP. The effectiveness of using the described approach is confirmed by the results of [9], which show an increase in the HC-oxidizing activity of microorganisms in symbiosis with plants by 20% compared with their free state in sea water. An additional property of this SVP, as noted above, is the ability of a number of algae to sorb TM cations present in seawater.

The fundamental difference between the methods using SVP and using mineral sorbents, the granules of which are populated by destructive bacteria, is the possibility of increasing the plantation efficiency during the natural growth of algae. The effectiveness of the main analogue decreases as the sorption capacity of the mineral sorbent saturated with contaminants decreases, supported only by the addition of new granules. The biofilter plantation is a self-reproducing system due to the ability of the association of algae and hydrocarbon-oxidizing microorganisms to develop even in the harsh conditions of the polar seas.

To populate the near-surface level of SVP, it is proposed to use fucus algae, the distribution of certain representatives of which corresponds to the region of its installation. The choice of species is dictated by its ability to dwell on the sea surface, withstanding the effects of ultraviolet radiation, water freshening, negative temperatures in winter, the effects of waves and currents. Types of Fucus, corresponding to the problem solved by the invention, indicating the ranges and depths of distribution, see table 1.

To populate the lower plantation level, it is proposed to use kelp algae (see Table 2). The exception is the Azov-Black Sea basin, where there are no laminaria, but you can replace them with the deep-sea representative of the Fucus C. barbata.

The use of laminaria in the thickness of sea water allows, in addition to creating a sufficiently large volume, populated with algae by microorganisms-destructors of NP, to provide water purification from a number of pollutants entering the coastal waters due to poor-quality treatment of industrial effluents. The ability to accumulate HM, including radionuclides, by brown algae was shown to be hundreds and thousands of times greater than their concentration in the environment [8].

An important point is the cultivation of algae on two horizons, which allows localizing and neutralizing surface pollution due to fucus algae near the surface level, withstanding higher concentrations of hydrocarbons. Due to the laminar algae of the subsurface level, the volume of SVP is enriched with oxygen, as well as the neutralization of the emulsified and dissolved in seawater part of the NP and traces of HM.

The proposed method is implemented in several stages. Examples of specific performance differ depending on the available species of marine flora, the characteristic microfauna and climatic conditions.

Option 1 (Barents Sea)

Preparation period. First of all, the study of the area of the proposed installation of the future SVP is carried out. At the same time, geographical, hydrophysical, and hydrochemical characteristics are estimated, including the bottom topography, velocities, and directions of the main currents, the potential directions of surface pollution are determined, and the nature and intensity of the total pollution of the bay for preliminary cleaning of the water area from unwanted floating objects is estimated. If necessary, a cleaning is carried out. To identify and remove sunken objects that are dangerous for SVP, a diving survey of the bottom and elimination of interference are carried out.

Then water samples are taken to determine the background content of petroleum hydrocarbons and, if necessary, HM, including radionuclides. The necessary hydrodynamic calculations are carried out to determine the configuration of the SVP, the mass and location of the gravity anchors, the length of the fastening cables, the length and diameter of the workpieces of the future elements of the plant's power circuit (base) for subsequent fastening to them ropes of smaller diameter, which act as a substrate for algae.

At the same time, billets and cuts of rope segments of the required diameter and installation of fastening elements on them are made. For the cultivation of fucus, modules from a polymer rope with a diameter of 10–20 mm and a length of at least 20 m (substrates) are cut, and for the cultivation of kelp, ropes with a diameter of 10 mm long, for example, 3–6 m (leads), are cut. If necessary, blanks for streamers for growing kelp are pre-sterilized in a solution, for example, NaClO, after which they are soaked for 10-12 hours in fresh water.

The method of settlement of streamers is selected depending on the required time for installation of the SVP. The streamers are either disputed, for which they are placed in baths for sowing spores and poured with a pre-prepared suspension of spores of kelp of the required concentration, or planted by weaving young sporophytes into the thickness of the ropes. The exposure time of the substrate in the planting baths necessary for settling and fixing spores on the substrate is 24 hours [14]. During the exposure of the substrate in the planting baths, the sowing process is monitored, the quality of which is judged by the residual concentration of spores in the solution. Controversy of streamers is less labor-consuming than interweaving of sporophytes, however, after challenging in August-September, algae in the Barents Sea will begin to function in association only in May-June (after spore germination and sporophyte development).

The selection in nature (on the lower horizon of the littoral) of kelp plants (young L. saccharina sporophytes 10–20 cm long) and the weeding of selected plants into pre-prepared streaks are carried out in groups of 3 plants every 5–10 cm. For accelerated colonization of kelp with microorganisms, they day is placed in containers with sea water, enriched with a natural composition from cultures of hydrocarbon-oxidizing bacteria in combination with other microorganisms-destructors of NP and nutrients.

To prepare this composition, the cultivation of the corresponding microorganisms is performed in advance. For the Kola Bay of the Barents Sea, such a composition may include, for example, representatives of yeast-like fungi of the genus Candida sp., As well as bacterial microflora - Pseudomonas sp., Corynebacterium sp., Brevibacterium sp., Nocardia sp., Arthrobacter sp., Streptomyces sp., Acremonium sp., which are the established components of the community of marine microorganisms of the coast of the Barents Sea, regardless of their level of NP pollution [9].

When planting Fucus plants, they are preliminarily selected for littoral, and weaving is done in prepared substrates in groups of three to four plants after 5 cm. Then, as in the case of kelp plants, the planted substrates are placed in containers with sea water enriched with the above-described composition of microorganisms . Prepared modules in the same containers are delivered to the installation site of the SVP.

The first stage of installation. At settlement points of the bottom of a given area of the bay being cleaned, gravity anchors are installed with steel buoys attached to them using steel cables or polymer ropes of power buoys to hold the floating power base of SVP from polymer ropes with a diameter of 30-40 mm, used as a frame for subsequent fastening of substrate modules in the surface layer of water.

The second stage of installation. With the help of fasteners, horizontal modules-substrates of the surface layer, planted with fucus algae, are attached to power ropes stretched at anchors. They are joined by floats to hold the streamers.

The third stage of installation. The installation of vertical streamers bearing laminaria sporophytes is carried out. At one end, the leads are attached to horizontal ropes, and weights are attached to their free ends, ensuring the vertical position of the leads in the water column. After that, the final tension of the power cables is made, which ensures the required configuration of the SVP and its orientation relative to the characteristic direction of the contamination.

Service SVP. During operation in the early stages, the algae growth, the state of the structure and the artificial symbiotic biocenosis are periodically monitored, and if necessary, the destroyed working modules are replaced, as well as thinning or seedling supplementation.

After the SVP enters the operating mode, the condition of the power frame, the integrity of the algal cover is periodically checked, and new working modules are added, if necessary. Periodically, water samples are taken within the SVP and on the approaches to it, as well as algae for laboratory research in order to determine the filtering properties of the SVP.

If necessary, the plantation can be expanded with new modules, changes in its configuration can also be made.

Option 2 (Black Sea)

It differs from option 1 in that during the preparatory period:

1) both types of working modules are prepared by interweaving pre-selected plants, moreover, a representative of the fucus species Cystoseira crinita is used for planting on the ropes of the surface layer, and a more unstable species of C. barbata is used for planting on vertical leads.

2) preliminary acceleration of the colonization of modules by microorganisms is not performed due to the fact that at sufficiently high water temperatures it occurs quite quickly in a natural way and begins immediately after the modules are immersed in algae planted in water.

Installation and maintenance steps remain the same as in option 1.

Option 3 (Japanese)

It differs from option 1 in the types of algae used (see Tables 1, 3) and in the possibility not to resort to artificial seeding with microorganisms similarly to option 2. In the case of formation of ice cover in the area where the SVP is located, it is necessary to provide for the possibility of deepening the plantation in order to avoid grinding the ropes with ice.

Option 4 (Avachinsky)

Similar to option 3.

The results of the study of the experimental SVP

The proposed method was originally developed for fine ("finishing") surface water treatment, which begins, as a rule, after the bulk of oil and oil products that have appeared on the sea surface are collected by known mechanical methods, as well as continuous preventive cleaning of the water area near pollution sources. However, the experience of studying the experimental SVP, installed in one of the bays of the Kola Bay, shows that the plantation can withstand quite serious volley emissions of NP. So, during an accidental spill of NP, when almost the entire surface of the water in the lip where the SVP is located was covered with a film, and the NP content exceeded 100 mg / l, fucus algae turned out to be functionally active. Moreover, due to the fact that pollution from the source entered the lip for a long time (about 15 days), they, delaying and accumulating NP, all this time were constantly exposed to their high concentrations. The mass fraction of NP in algae reached 6 g / kg (dry weight). However, in this case too, they retained functional activity, although at a lower level (30–40% lower) than in pure water. For the Barents Sea variant of SVP in zones of increased intensity of movement of water masses, it turned out to be preferable to use the species L. digitata, which better tolerates the effects of turbulent flows.

The pilot SVP, built and operating according to the described principle, worked for more than 18 months in rather severe conditions, withstood several storms and confirmed the effects of localization and neutralization of hydrocarbon pollution. The indicated period is not the limit of the existence of the supporting structure.

A parallel experiment in the Dalnezelenets Bay of the Barents Sea showed the possibility of using such SVPs as protective barriers for mariculture farms, which is especially important in connection with the development of cage and ichthyofauna in the Barents Sea.

Analysis of the technical results of the use of the invention

Studies confirming the effectiveness of SVP were carried out mainly in vitro at the laboratory base of MMBI KSC RAS, Moscow State University M.V. Lomonosov and VNIIM them. D.I. Mendeleev. The experimental results are shown in tables 3-7, table 8 summarizes the final data, allowing to judge the advantages of the proposed method.

Samples of Fucus algae to confirm their ability to assimilate (include in the metabolism processes) hydrocarbon fractions of NPs were collected from the mentioned SVP installed in one of the bays of the Kola Bay polluted by industrial waste in the Barents Sea. Control samples were taken in the waters of the same bay clean from NP. Then all the samples were transferred for research to the sector of chromatography and chromatography-mass spectroscopy of VNIIM. The results of the analysis are given in table.3.

Table 3
Assimilation of hydrocarbon fractions of petroleum products by biennial samples of algae F. vesiculosus №№ Place by date of sampling The content of petroleum products on the surface and in the tissues of algae SVP Total mass fraction, mg / kg Removed from the surface of algae, mg / kg Isolated from tissues NP, mg / kg one 2 3 four 5 one Sample No. 1. Clean area (Yarnyshnaya Bay, 06/24/08), Traces 0 <50 2 Sample No. 2. Contaminated area (port, Murmansk, 24 hours after capture 25.06.08) 6956 3228 3718 3 Sample No. 2 after 7 days of storage (07/02/08) 1084 832 252 four Sample No. 2 after 14 days of storage (07/09/08) 807 25 782 * During the experiment, the algae were kept in a cooled chamber at a temperature of 6 ° C and a humidity of 98%.

According to the results of the experiment, it can be concluded that the total amount of hydrocarbons located on the surface of fucus algae is non-linear in nature. At the same time, the rate of assimilation and processing of Fucus hydrocarbons decreases as the total mass of surface contamination of algal thalli decreases, on the one hand, and as their tissues become saturated with processed products, on the other. The data presented confirm the fact of the assimilation of Fucus oil hydrocarbons and, therefore, the possibility of using the latter for the processing of surface NP films.

These data allow us to carry out preliminary calculations of the rate of assimilation of Fucus NP, which is important for assessing the parameters of the SVP. Particular attention should be paid to the change in the detected NP in the tissues of Fucus (column 5). For the first 7 days of exposure in a heat chamber, 3466 mg / kg NP was converted at an average conversion rate of 495 mg / kg / day. For the next week of storage, a significant decrease in the conversion rate is noted, since only 252 mg / kg NP was processed at an average speed of 36 mg / kg / day.

Such a decrease in processing speed in laboratory conditions does not mean that SVP as a whole stops the process of assimilation of NP. The fact is that in nature, over 14 days, the flow through the SVP only because of the occurrence of tidal currents changed the direction of movement at least 28 times (semi-diurnal tides are characteristic of the Kola coast). At the same time, the oil slick either rolled away from the SVP or covered it again. Moreover, that part of the NP, which had previously been “in the rear” of the SVP, had the opportunity to return and settle on fucus in the rear. Thus, due to the reverse processes of the flow around the SVP in the surface modules, the redistribution of the NP occurs and the processes of assimilation of the NP in previously less polluted zones are enhanced.

The nature of the interaction of SVPs with the aquatic environment depends entirely on weather conditions superimposed on stationary phenomena, such as tidal currents. Table 4 shows the data on changes in the speed of movement of water masses inside the SVP obtained during the inter-tidal period, when the current in the bay was formed under the influence of a relatively weak wind surge during sea waves of no more than 1 point. To measure the hydrodynamic activity inside the SVP, the method of gypsum structures was used (dissolution in a stream of gypsum balls with a diameter of 31 mm).

Table 4
An example of a change in the flow velocity depending on the depth and distance from the input section of the SVP SVP sites Depth of installation of sensors, m The distance from the input section of the SVP to the installation site of the speed sensor (m) and the flow velocity (cm / s) 0 5 10 fifteen one 2 3 four 5 6 Coastal
(interior) 0.2 32,5 27.5 26.6 16.1 3.0 19.5 19.6 15.0 13.0 7.0 14.5 22.8 14.7 9.2 10.0 14.3 17.3 - - Remote 0.2 58.5 23.8 28.3 12,2 from the coast 3.0 52.3 17.6 20,2 9.3 (external) 7.0 45,2 14.8 22.2 10.5 10.0 38.8 14.9 → direction of the main pollution transfer at the time of the survey

The direction of flow in the area of the SVP installation is not constant, which is associated with a change in the tidal and wind components, the vectors of which are usually multidirectional. In the case of increased wind and increased waves against the background of the tide, the one-dimensional nature of the interaction of the medium with the SVP is replaced by a more complex one. As a result, ascending flows appear, the direction of water movement with depth changes, the load on the algae increases, turbulence occurs, as a result of which the thalli not only deviate with the flow, but are included in oscillatory processes with horizontal and vertical components. All this enhances the transfer of hydrocarbon pollution and evens out their redistribution throughout the volume of SVP.

Other studies were carried out in laboratory conditions, while the population of Fucus and kelp was studied by hydrocarbon-oxidizing microorganisms (Table 5), their oxidizing ability (Table 6), and the integral indicators of sea water purification from NP by Fucus algae (Table 7).

The results presented in Table 5 make it possible to evaluate the relative role of fucus and kelp in oxidation of NS by epiphytic hydrocarbon-oxidizing microorganisms concentrated on the surfaces of thalli.

Table 5
Population of Fucus and Kelp with hydrocarbon-oxidizing microorganisms at characteristic points in the water area of the port of Murmansk (Kola Bay) Object of study MMS (HC-oxidizing bacteria) Zobella medium (saprotrophic bacteria) height NVZ, cells / ml NVZ, cells / cm ² height NVZ, cells / ml NVZ, cells / cm ² one 2 3 four 5 6 7 VG water (polluted water from the pier) 10 ¹
10 ¹ fifty 10 ²
10 ³ 1200 HF water (pure water taken from a clean place offshore) 10 ²
10 ¹ 120 10 ²
10 ³ 1200 FC-2r (fucus from a clean place, 2 replicates) 10 ¹
10 ¹ 125 10 ³
10 ² 2987 FG-1p (dirty fucus from the pier, 1 repetition) 10 ³
10 ² 1728 10 ⁴
10 ⁴ 71984 LCh-1r (pure kelp from the barrel, 1 repetition) 10 ²
10 ¹ 150 10 ³
10 ³ 313 LG-1r (contaminated kelp from the pier, 1 repetition) 10 ¹
10 ² 150 10 ³
10 ² 1500 Notes: MMS - marine mineral environment, NVZ - the most probable value;
further calculations use column 4 data.

It was revealed that the number of bacterial cells on the surface of kelp thallus can reach 6250 cells / cm ² , including hydrocarbon-oxidizing 150 cells / cm ² . Given the average plate area of two-year kelp in the Barents Sea 3600 cm ² , the total number of bacteria on a double-sided plate reaches 22.5 million cells, including hydrocarbon-oxidizing 540000 cells. The ratios between the number of HC-oxidizing microorganisms on the thalli of Fucus and kelp are approximately 11 times different in favor of Fucus.

Comparative studies have shown that these indicators are more than four times higher in kelp from contaminated habitats compared with kelp from clean places. It should be noted that under real conditions, a greater number of such microorganisms are concentrated not on the surface of the plate, but in its boundary layer, which, depending on its size and speed, flows around the water flow from a few millimeters to 2 cm.

The results shown in Table 6 make it possible to evaluate the oxidizing ability of hydrocarbon-oxidizing microorganisms both in fucus and in kelp. It is likely that in real systems these indicators for fucus and kelp are different.

The next stage of the experiment was to determine the oxidizing ability of epiphytic hydrocarbon-oxidizing microorganisms, the substrate for which are thalli of algae. The experiment included sonication of Fucus thalli with ultrasound to desorb bacteria. Thalli weighing 1.78-1.90 g were washed with a sterile 3% sodium chloride solution, placed in a 100 ml sterile glass beaker containing 50 ml of sterile MMC mineral medium and subjected to ultrasonic treatment. Then, the purified fucus was removed from the glass, and its contents were poured into a 0.5 L rocking cup containing 150 ml of MMS medium, where 1 ml (0.76 g) of sterile diesel fuel (DT) imitating NP was then introduced.

The flasks were placed on a shaker and incubated at 20 ° C for 3 weeks, after which the residual DT was extracted with carbon tetrachloride, settled for 24 hours, the bottom layer of the extractant was drained and analyzed on a spectrophotometer. The results of the analysis are given in table.6.

Table 6
Laboratory studies of the oxidizing ability of HC-oxidizing microorganisms №№ Sample Fucus sample weight, g The remainder of DT in a glass, mg / l DT consumption,% Note one 2 3 four 5 6 one Fucus clean 1.80 4000 40,0 2 Fucus clean 1.78 3800 42.0 3 Fucus contaminated 1.76 3300 49.0 four Fucus contaminated 1.94 3300 49.0 5 Fucus contaminated 35.0 0.174 63.0 Note: - as a sample of NP, sterile diesel fuel (DT) was used at an initial concentration in the vessel of 6500 mg;
- epiphytic hydrocarbon-oxidizing microorganisms obtained by desorption from the surface of algae of the species Fucus vesiculosus;
- experiment 5 was carried out in conditions different from experiments 1-4 by placing fucus from the contaminated area of the sea in 100 ml of a solution of diesel fuel with its initial concentration of 0.316 mg / l.

Based on the data in Table 6, we can conclude that the ability of epiphytic microorganisms to destruct NP in a laboratory experiment. The maximum consumption of DT by bacteria within 3 weeks of exposure was 49% of the control. At the same time, HC-oxidizing microorganisms that live on the thalli of fucus taken at contaminated NP points in the water area consume 7-9% more diesel fuel than their counterparts that live on fucus extracted on pure thallus from NP. The latter confirms that exposure to fucus in a medium with a high content of DT increases its HC oxidative activity. Thus, it is obvious that the preliminary treatment of fucus with a small amount of DT allows accelerating the withdrawal of the bacterial component of the NP oxidation process to the “working” mode.

In addition to the experiment on a Fucus coated with an oil film (Table 3), in 2008, a study of the absorption of pure Fucus DT at various concentrations of the latter in the medium was conducted at MMBI (Table 7).

Table 7
The results of a laboratory experiment for the purification of sea water by fucus algae (PV)
(sampling area - Kola Bay, Belokamennaya Bay, 09/02/08) Object / exposure time, Change in the content of NP in sea water (mg / l) and algae, mg / kg Clean water Pure water + PV Water + DT Water + DT + PV Water + DT + PV Water + DT / PV Experience one 2 3 four 5 6 Water / Fucus Control 0.05 0.05 1.54 1,53 6.42 12.24 / 0.165 3 days - - - 0.41 1.9 - 7 days 0.05 0,034 1,54 0.26 (0.32) 0.72 2.84 / 5.62 14 days 0.05 0,03 1,52 0.06 (0.09) 0.09 / 8.68 21 days 0.05 0,03 1,54 0.032 (0.04) 0.04 (0.8) - Note: - MPC of NP content in sea water 0.04-0.05 mg / l;
- thalli of algae with 6-7 dichotomies were used (age 3 g);
- used "summer" diesel fuel;
- the experiment was carried out in battery cups with a capacity of 3 l on magnetic stirrers at a temperature of + 8-10 ° C;
- after adding fuel to the glass and intensively mixing it was allowed to stand for a day, and then the surface film was removed;
- the values in parentheses in columns 4 and 5 are the result of 2 repetitions of the experiment;
- in column 6 the ratios of the content of diesel fuel in water and in the tissues of thalli of algae are given.

The results of this experiment show that in the water-DT-PV system, in contrast to the water-NP-PV system, the absorption process is significantly accelerated. This is probably due to better conditions for the interaction of DT and the surface of the PV membranes at higher temperatures. In this case, as in the case of the NP film (Table 3), in the last week of the experiment, the processing rate of DT in tissues decreased: judging by the data of column 6, the average processing rate in the first 10 days was 0.38 mg DT / kg PV / day, and over the next 7 days - 0.31 mg DT / kg PV, i.e. about 18% less. Thus, the downward trend in the processing rate of DT in fucus tissues, as well as that for NP, is manifested, although not so strongly. It can be concluded that in warm seas for the disposal of DF spills, it is possible to use the proposed SVP with greater efficiency.

Table 8 summarizes and summarizes the results of the above experiments on the oxidation and processing of PN, allowing a preliminary assessment of the effectiveness of the SVP for the northern version.

The data table. 8 indicate that

1) the main effect of the pilot SVP is due to the use of the natural symbiotic association “algae-macrophytes - HC-oxidizing microorganisms”;

2) from column 9 of the table it follows that the effectiveness of bicultural SVP is almost 2 times higher than that for monocultural;

3) the process of assimilation of NP by fucus at a temperature of 2-12 ° C is only about 6% of the total positive effect given by the monocultural option;

4) the advantage of the monocultural variant on fucus is that fucus is able to localize the surface spot of the NP and thereby create the conditions for more efficient development of hydrocarbon-oxidizing microorganisms, rather than a buried and free from film NP kelp;

5) the productivity of SVP on oxidation of NP in warm waters at a water temperature of about 25 ° C increases by about 5–7 times [7], however, due to the need to remove not the DT propagating along the surface, but part of it penetrating into the subsurface layers , the question is about replacing laminaria (stability limit 15 ° C) with more heat-resistant algae species, for example, for the Black Sea - with cystosira bearded. Such a plantation can work here at any time of the year.

List of references

1. Kamenshchikov F.A., Bogomolny E.I. Removal of oil products from the water surface and soil. - M. - Izhevsk, 2006 .-- 528 p.

2. Serova I.P., Petrov B.C. Oil in ice-bound seas and the use of biotechnologies for the destruction of oil pollution in the Arctic // Arctic seas: bioindication, environmental conditions, bioassay and pollution destruction technology. - Apatity, 1993 .-- S.127-136.

3. S.A. Patin. Oil and ecology of the continental shelf. - M.: VNIRO Publishing House, 2001 .-- 248 p.

4. Application of the Russian Federation for invention No. 20011135951/13 “Method for producing a biosorbent for purifying natural waters from oil and oil products”.

5. RF patent for invention No. 2255052 “A method for purifying the aquatic environment from oil pollution and a biological product for purifying the aquatic environment from oil pollution”.

6. RF patent for the invention No. 2182529 "Consortium of strains of microorganisms-destructors: Bacillus species, Aeromonas species, Alcaligenes eutro-phus, Alcaligenes denitrificans used to clean soils, soils and water from oil pollution."

7. Ilyinsky V.V. Heterotrophic bacterioplankton: ecology and role in the processes of natural purification of the environment from oil pollution. Abstract. dis. Doct. biol. sciences. - Moscow, Moscow State University, 2000 .-- 53 p.

8. Kamnev A.N. The structure and functions of brown algae. - M.: Publishing House of Moscow State University, 1989 .-- 200 p.

9. Peretrukhina I.V. Heterotrophic bacterioplankton of the littoral of the Kola Bay and its role in the processes of natural water purification from oil hydrocarbons. Abstract. dis ... cand. biol. sciences. - M., 2006 .-- 25 p.

10. Voskoboinikov G.M. Mechanisms of adaptation, growth regulation and prospects for the use of macrophytes of the Barents Sea. Dis. for a job. scientist Art. Doct. biol. sciences. - Murmansk, MMBI KSC RAS, 2006. - 465 p.

11. Kizevetter I.V., Sukhoveeva M.V., Shmelkova L.P. Commercial algae and herbs of the Far Eastern seas. - M .: Food. industry, 1981.

12. Afanasyev D.F., Stepanyan O.V. Size and age structure of the cystozira population of the North Caucasian coast of the Black and Azov Seas. // Environment, biota and modeling of environmental processes in the Sea of Azov. - Apatity: Publishing House of KSC RAS. 2001 - S.125-135.

13. Selivanova O.N. Absorption of toxic elements by some brown algae from contaminated areas of Avacha Bay // Sat. scientific articles on the ecology and environmental protection of Avacha Bay. - Petropavlovsk. - Tokyo: Publishing House of the Goskomkamchatekologiya, 1998. - S.39-45.

14. Makarov V.N., Dzhus V.E., Matishov G.G. etc. Scientific and practical aspects of the cultivation of sugar kelp in the Barents Sea: Prep.-Apatity: Publishing House of KSC RAS, 1986 - 35 p.

Claims (1)

The method of purification of marine coastal waters from film and dispersed in the surface water layer of petroleum products, including the placement in the contamination area of a filter filled with a sorbing medium populated by oil-oxidizing microorganisms, characterized in that a floating algae plantation is used as the sorbing medium, the basis of which is a system of interconnected synthetic ropes planted with kelp and fucus algae, the kelp being placed in the water column on vertical ropes of length 5 m, and fucus algae are placed on horizontal ropes in the surface layer of water.