RO129465A2 - Installation for aerating water in lakes, tanks and rivers having low flowing rates - Google Patents

Abstract

The invention relates to an installation for improving, by aeration, the quality of the water in lakes, ponds, purification tanks or river courses with low rate, without deteriorating the equilibrium between the aquatic medium layers. According to the invention, the installation consists of a hydraulic machine () which is provided with a casing () with double aspiration and two rotors () with pressurized discharge, through a tubing () connected to a flexible tubing (), with circular cross-section, to the free water surface, the flexible tubing () being provided with a circular discharge diffuser () which allows the water pumped from the depth layers to be symmetrically distributed on the entire surface of the lake and which is in connection with a support (), supported, in its turn, by three floats (), on the support () there being placed some solar photovoltaic panels () used for supplying electric energy to a direct current motor (), coupled to the rotors () whereto there is added an actuation and automation module () and a battery of storage cells (), in order to store energy, the water recycling being carried out by cumulation of the two effects: the direct one obtained by pumping water from hypolimnion towards the free surface and the one induced by the water descending from epilimnion towards the depth layers, which favours the ammonia elimination and the phosphorus precipitation, and the blue-green algae flowering control determining the oxygen need for sediments to decrease, reducing the possibility of the occurrence of the anoxic conditions in the water in hypolimnion.

Description

The invention relates to an environmentally friendly installation whose operation leads to the improvement of the water quality of lakes, ponds, sewage ponds or low speed water courses. The purpose of using the plant is to promote the process of aerating the water by recirculating it in a regime close to the natural one, to deteriorate the balance between the layers of the aquatic environment.

Water is an open system exchanging energy and matter with adjacent systems / environments. The water is subject to increasing anthropogenic pollution, the sources being both domestic and industrial, being known over 80,000 natural chemicals or created by industrial processes that can create billions of effects through their combination. The quality of the water, determined by analyzing the organoleptic, physical, chemical, biological and bacteriological characteristics, can be degraded as a result of the pollution of different types: the fertilizing, bacterial, chemical, suffocating pollution. Naturally, surface waters have the capacity to self-purify by isolating impurities tending to the existing equilibrium state before contamination. Thus, for conservative substances, water has only the role of redistribution following slow processes of neutralization; for the biogenic substances that take part in the biological processes, the self-purification is carried out through the biochemical processes (the case of the mineral forms of phosphorus and nitrogen which are easily assimilable organic compounds); for other substances dissolved in water (eg toxins) self-purification occurs through their chemical and microbiological transformation. All pollutants participate in mass transport processes and are transformed either by physical, chemical, biological or biochemical processes.

The forms of pollution can occur separately or together - the most common case. One such case is that of eutrophication, a natural evolutionary process that can be accentuated by human intervention and in which, with the breakdown of the metabolic chain in closed aquatic basins, the accumulation of bottom deposits, representing a secondary source of biogenic elements, takes place. enrichment of water with nutrients. mainly nitrogen and phosphorus, leads to algal blooms. an exaggerated growth of aquatic macrophytes, a high turbidity, a deoxygenation of the water from the bottom of the lake and. In some cases, it induces an unpleasant odor and taste of water. Eutrophication can be:

a) natural - enrichment with nutrients is performed only by natural agents, which have a discontinuous flow. in this case the phases of the process alternate with the increase and decrease of the nutrient concentrations, in accordance with the climatic conditions (light, temperature);

b) artificial - caused by human intervention (agricultural fertilizers, tree clearing, animal husbandry, urbanization and industrialization). in this case the rate of evolution of the eutrophication process accelerates, its impact becoming especially important and impossible to ignore.

Once eutrophication occurs. the aquatic basin evolves from ultraoligotrophic. oligotrophic and mesotrophic towards the final stage of eutrophic and hyperereutrophic as a result of its aging and disappearance by transforming it into swamp. The actual consequences of water eutrophication in aquatic basins are among others: the increased technical difficulty in using water directly from aquatic basins, either for treatment for use as drinking water or even for industrial uses: clogging of filters and increased corrosion of pipes and fittings: the significant diminution of the biological potential by degrading the quality of the water and implicitly of the industrial fishing; suppression of leisure activities, etc. Eutrophication alters the ecological balance of the ecosystem, generating serious problems of an ecophysiological nature, the most well-known effect being the proliferation of blue-green algae - also known as cyanophytes.

cyanobacteria or cyanoprocaryotes. which affect both the condition of the lakes and the uses of the water. In order to maintain the quality of the water, it is necessary to monitor its parameters. in the current physical-chemical and biological analyzes being monitored:

a) oxygen regime indicators (Dissolved steel, CCO-Mn, CC'O-Cr, UBO 5):

b) indicators of the regime of nulrients (ammonium, nitrites, nitrates, phosphates);

c) indicators of planktonic biocenosis (phytoplankton, zooplankton);

d) auxiliary physico-chemical and bacteriological indicators (CO ₂ pill. alkalinity. Mn. e. loyal co-uniform bacilli, etc.). These indicators can have values between certain limits, which includes lakes in the oligotrophic, mesotrophic or eulrophic categories:

lakes

Degree of oxygen saturation O? (%) Total nitrogen N (mg / dm ^J )

Total phosphorus 1 '(mg / dm ³ )

Phytoplankton biomass (mg / dm ^J ) oligotrophs minimum 70 maximum 0.3 maximum 0.03 mesotrophic lakes

- 70 rnaxim maximum 0.1 (ring) -20 (e.xcl) eulropic lakes below 40 minimum 1.5 minimum 0.1 5 minimum 20

Among the methods for reducing the eutrophication of lakes and improving the quality of the water are mentioned: chemical methods (precipitation of the nullulines; dredging of the anoxic sludge from the bottom of the lake or its inactivation); biological methods (mowing and extraction of vegetation and algae, even fish; application of toxic substances - herbicides, algicides. pesticides; direct manipulations of ecological balance and the food chain by introducing allochthonous species, etc. and mechanical aeration methods. in the case of mechanical methods studies In the field it shows that the refresh of the water surface improves up to 7 times the transfer of gases both to and from its volume in comparison with a gloss of moving water again, thus better absorption for oxygen and an elimination of methane or ammonia occur.

The concerns for the purification of the water of lakes, ponds, basins are known. using mechanical methods that depending on the process used can be achieved by means of aeration properties.se or mixing. In the first case. the installations inject air into the layers below the gloss of the water creating a certain degree of bubbling while in the second only a glow of the water glow takes place and the water from the depth layers is brought to the free surface. The difference between the two processes is that while the aerials produce a relevant mass exchange between the layers of the aquatic environment, the mixing plants produce effects in the superficial layer exposing the deep water layers to the air. Regardless of the type of installation used, its efficiency must be viewed globally. Thus, an example of a pneumatic aerator having energy autonomy obtained through the use of wind and solar energy sources is presented in: “Surface water aeration plant - RO 127188A2 - in which the active element of the installation is an air compressor. In another aeration lip but this time of mixing surface is presented in: "Watcr circulalion syslems for ponds. lakes. and olher bodies of water '- US 7285208 and related US 7306719, US 7332074, US 7906017, US 805709 - in which the active element of the installation is an axial rotor operated by solar energy.

The proposed installation according to the invention relates to a modified transverse type hydraulic machine 1 placed in an installation whose discharge section is below the free water level and which allows its mechanical aeration on the principle of mixing, having the advantage that it does not disturb the natural stratification of the aquatic environment. / Xpa that runs through the installation is sucked from the depth layers and pushed to the surface by the transverse machine

Ο 1 2 - Ο Ο 7 Ο 6 - Ο 8 -W- 20¾ placed near the bottom of the pool. The direct upward flow of water passing through the flexible pipe 2 mounted at the discharge section of the hydraulic machine induces once the surface has reached an additional radial movement both on the free and downward surface due to the difference in density. The global movement induced by the installation prevents phosphorus and nitrogen from becoming sources of flowering of blue-green algae which leads to the occurrence of toxic conditions of aquatic life. The mixing of water through the submersible installation allows nutrients to enter the food chain from the lake and controlling the level of phosphorus and nitrogen is no longer a problem. The lake becomes productive, the biodiversity is reinvigorated, the water becomes clean, the volume of dissolved oxygen increases, the pH values decrease. and chlorophyll. as far as the fish breeding rate is concerned it can reach approx. 15-20 times higher than the case before the installation.

The installation is designed in such a way as to minimize the degree of turbulence of the surface water mixing process while recirculating the water from the deep layers. The flow of water directly through the installation induces a secondary flow of approx. 2-2.5 times higher in the rest of the pool. In the recirculation process, the change of the shape of the free surface in the form of the wind waves does not influence the flow induced by the installation precisely due to the almost laminar flow regime.

The proposed aeration system is floating, mobile, energy autonomous and has as main element a modified transverse hydraulic machine 1 which operates at low rotational speeds so as not to disturb the aquatic microsystem by deteriorating the balance between its layers, ensuring the oxygenation of exogenous water (dissolution of atmospheric oxygen). up to 50 mg oxygen / day / nU). The transverse hydraulic machine immersed in the depth layers works drowned, requiring a low energy consumption to compensate for the frictional load losses of the water, which at its slow speeds are almost negligible, and to allow the initiation of the radial motion to the free surface in the circular section. discharge. As a result, the machine load will be approx. 5-20 mm with water. On the other hand, imposing the condition that the flow velocity of the water is reduced in order not to disturb the balance of the aquatic microsystem also causes the flow provided by the hydraulic machine to be reduced. in the above conditions it turns out that the power required to drive the hydraulic machine will also be lower, less than approx. 100 W. considering the efficiency of the installation here. Given the low energy consumption, the aeration plant has the advantage of supplying electricity from renewable sources. in this case, the solution of photovoltaic solar panels is considered sufficient.

Each of the rotors of the hydraulic machine 3 has the advantage of a large axial length, which makes it easy to obtain several types of dimensions for the aeration systems through simple modulation. Another advantage regarding the positioning of the rotors 3 is that the section of the double suction 2 is parallel to the bottom of the water, which allows on the one hand the avoidance of colloidal substances, sand, vegetation etc. and on the other hand it helps the induced movement of water from the deep areas. In the optimum version, the hydraulic machine is equipped with two rotors 3 having 2 different aspirations and a single discharge 4 construction that favors the symmetry of the induced flow.

The electric motor 9 used to drive the hydraulic rotors is DC, brush strokes, with low rotational speed and high rotational moment. For reduced powers, electric motors can be used directly coupled to the hydraulic rotors and for higher powers can be used electric motors with reducer. which ensures constant rotational speeds in the swing torque conditions. A remote actuation, adjustment and communication module 10 is attached to the installation.

The power supply of the electric motor can be done using photovoltaic solar panels 8 whose power is calculated according to the solar potential of the site and which can be chosen to supply 12 V for reduced power of the installation or 24 V - 48 V for large installations. To ensure the functioning of the system and at night it is equipped with a battery of batteries 11.

the flexible discharge valve 5 of the installation has a circular section and at its top is a diffuser 6 placed under the water mirror with the roller to form a symmetrical radial flow.

The entire installation is supported by a metallic structure 7 to which are attached three floating 12 cylindrical with the possibility of adjusting their position in order to obtain a horizontal position of the diffuser of the discharge pipe.

The technical problem solved by the proposed installation is that in the process of water aeration it removes the disadvantages of other similar installations based on the injection of air into the layers of depth, a process that leads to an intense mass exchange between the layers of the aquatic system and. thus, in breaking the balance between them. The proposed installation realizes the aeration of the water by slowly raising the volumes of water from the hypolimnion, creating at the same time a recirculation at a low speed of its phenomenon specific to the natural environments only in the spring and winter periods. Another problem solved by using the proposed installation is that unlike the aerators using the method of air injection whose effect is local, the mixing process exposes practically the entire surface of the water through the effect of the horizontal movement, almost laminar motion, therefore having a high degree of coherence. Finally, analyzing by comparison the overall efficiency of the two types of proposed plants has a very low energy consumption and due to this advantage it can work both during the day and at night which compensates the nocturnal oxygen consumption of the vegetation.

The installation can be used in several ways depending on the quality of the water considered respectively the application itself: for the purpose of aerating the water from the hypolimnion or for the purpose of limiting the flowering of the blue-green algae in the water of the epilimnion. In the first case, the installation used to aerate the water from the hypolimnion allows the transport of oxygen to the lake sediments, preventing the release of hydrogen sulphide, phosphorus, manganese or iron. It can disrupt the sediments or induce changes in the aquatic environment. in the second case and especially in the wastewater, the installation allows the permanent removal of the lipid film from the free surface of the water which leads to the intensification of the release of methane, thus increasing the anaerobic activity of the sedimentary sludge. Also, the permanent movement of the surface of the water having the PLL and the amount of dissolved oxygen raised due to the algae, to which is added the recirculation process favors the elimination of ammonia (N) and the precipitation of phosphorus (P). On the other hand, the control of the flowering of their blue-green algae causes the need for oxygen for the sediments to decrease, reducing the possibility of anoxic conditions occurring in the water in the hypolimnion.

List of parts in the drawing machine hydraulic housing with double suction rotors pipes discharge flexible pipes diffuser support support panels l 'olovoltaiee electric motor why drive and automation

1 battery of floating batteries cf- 2 O 1 2 O O 7 O 6 - O B 10- 201 ^ words

Claims (5)

1- Water installation of lakes, reservoirs and rivers with low flow velocity, characterized in that it uses a modified transverse hydraulic machine 1 having double suction 2, two rotors 3 and the discharge pipe 4 common and can be positioned at different dimensions below the free level of the water and pushing the water from the deep layers towards the surface in order to recycle it. 2. Water installation of lakes, reservoirs and rivers with low flow velocity, characterized in that the double suction section 2 of the hydraulic machine according to claim 1 is placed such that the water entering its rotors 3 follows a direction parallel to the bottom. water which allows it to increase the range of speeds of water recirculation, as opposed to the known variant with axial rotor in which the suction pipe is placed perpendicular to the bottom of the water presenting a higher risk of disturbing the balance between the layers of the aquatic environment. 3. Water installation of lakes, reservoirs and rivers with a low flow rate, characterized in that the water flow provided by the modified hydraulic machine 1 and discharged through the flexible pipe 5 through the discharge diffuser 6 is not influenced by the waves. surface induced by the wind due to the position submerged to great depths to the free surface. 4. Water aeration system for lakes, reservoirs and rivers with low flow rate, characterized by being energy-independent being supplied with solar energy by means of photovoltaic panels 8, operating throughout the day and night, a condition for continuing the process aeration in this part of the day when the algae in the aquatic environment become consumed of oxygen dissolved in water, and being equipped with a system of electrical energy storage consisting of a battery of batteries 11. 5. Water aeration system for lakes, reservoirs and rivers with low flow velocity, characterized in that the movement of the water obtained at its discharge through the discharge diffuser 6 produces a quasi-laminar movement on the free surface of the water which allows the transmission in the form from concentric energy waves on the surface of the entire lake, reservoir or stream having a low flow rate, improving the process of low oxygenation of the case of the aerator, operating on the principle of injecting air into deep layers as well as for: recovering the pl-l level from water, the release of ammonia in the form of gas. phosphorus precipitation, resulting in the control of algal growth in the aquatic environment, respectively, of the anacrobial activity with effect on the increase of the water quality. ^ “2012-00706-θ 8 -10- 201 /, S ' / / / / , Μ / / / / s' .s s s' Fig 1