Aquatic ecosystem for treating high-salinity wastewater

Abstract

The invention discloses an aquatic ecosystem for treating high-salinity wastewater. The system comprises an aquatic environment, aquatic animals and aquatic plants, grass carp is selected as the aquatic animal and plays a role in stirring to promote the diffusion of salt; the aquatic plants comprise submerged plants including watermifoil, hydrilla and hornwort and floating plants including duckweed and the like, and the aquatic plants have certain salt tolerance; according to the method, the aquatic ecosystem is constructed to remove the salt, the design is more environment-friendly and is expanded to the river water body with the salt content exceeding the standard, and the salt can be removed to a certain extent by culturing aquatic animals and plants beneficial to salt removal, so that the use of chemicals can be avoided, prevention and treatment are performed by a biological method, and the economic benefit is increased. The biological diversity and the stability of the aquatic ecosystem are improved, and the aquatic ecosystem is environment-friendly, low in cost and capable of reducing water pollution.

Description

Technical Field

[0001] This invention relates to the fields of ecology and water treatment technology, and more specifically, to an aquatic ecosystem for treating high-salinity wastewater. Background Technology

[0002] Aquatic ecosystems are among the most important ecosystems on Earth, closely intertwined with human production and daily life. An aquatic ecosystem consists of multiple components, including water bodies, benthic organisms, plants, sediment, and shorelines, as detailed below: Water bodies: Water bodies are the main component of aquatic ecosystems. Water bodies can be of different types, such as freshwater, saltwater, or estuaries. Water bodies contain a rich variety of aquatic organisms and the basic elements of the material cycle.

[0003] Benthic organisms: Benthic organisms in aquatic ecosystems include a wide variety of organisms. Benthic organisms play an important role in regulating the ecological environment, such as water fleas, hydras, dragonfly larvae, turtles, and crabs.

[0004] Plants: Plants in aquatic ecosystems can be phytoplankton, aquatic plants, or riparian plants. If suitable aquatic plants are artificially cultivated based on local conditions, these plants can effectively purify the water. Plants provide energy sources for aquatic ecosystems and play important ecological functions within them.

[0005] The components of an aquatic ecosystem interact to form complex ecological relationships, which together maintain the balance of the aquatic ecosystem. This balance is crucial for the health and sustainable development of the aquatic ecosystem.

[0006] Salt pollution refers to a situation where the salt content in water or soil exceeds normal levels, typically referring to chloride, sulfate, and nitrate plasma. Existing technologies disclose various methods for salt removal. For example, Chinese patent application CN202411475691.0, entitled "An Adsorbent for Removing Perchlorate from Water and Its Preparation Method and Application," discloses a simple and efficient method for preparing salt removal adsorbents. However, if the use of toxic chemical reagents in this method is not properly handled, it may cause heavy metal or organic pollution to soil and water bodies. For example, bromides and quaternary ammonium compounds may have bioaccumulation and persistence, and long-term residues may threaten aquatic ecosystems. Chinese patent application CN202111408332.X, entitled "A High COD, High Salt Wastewater Treatment Technology," discloses a high COD, high salt wastewater treatment technology. High ammonia nitrogen and high COD wastewater is collected in a collection tank and pumped through pipelines to an integrated Fenton oxidation tower. It is highly efficient and designed for specific high salt and high COD wastewater. It may not be economical for low salt or low concentration wastewater, and the process is complex and costly, and may generate other byproducts. Summary of the Invention

[0007] This invention addresses the problems of existing salt removal technologies, such as complex processes, high costs, and environmental pollution, by constructing an environmentally friendly aquatic ecosystem for treating high-salinity wastewater. This system can be extended to rivers with excessive salt content, where aquatic plants and animals beneficial for salt removal are cultivated to achieve a certain degree of salt reduction. Using biological methods for wastewater treatment increases the biodiversity and stability of the aquatic ecosystem, while also being environmentally friendly, cost-effective, avoiding the use of chemicals, and reducing water pollution.

[0008] The technical solution of the present invention is described in detail below.

[0009] This invention provides an aquatic ecosystem for treating high-salinity wastewater, the aquatic ecosystem comprising: At least two submerged plants; at least one floating plant; at least one aquatic animal; wherein: The submerged plant was selected from *Myriophyllum spicatum* ( Myriophyllum verticillata ), Elodea ( Hydrilla whorled ), goldfish algae ( Ceratophyllum submersum ), Salthorn Grass ( Salicornia europaea ), Hippocampus Sesuvium purslane ), Potamogeton crispus ( Stuckenia pectinata ) or Sichuan seaweed ( Ruppia maritime At least two combinations of ); The floating plant is selected from water hyacinth ( Pontederia crassipes), Water lily ( Water lily nuciferaGaertn ),duckweed( Lemna minor ), water lilies Tetragonal water lily ) or fern-like Azolla ( Azolla filamentous At least one of the following; The aquatic animal mentioned is grass carp ( Ctenopharyngodon idella ).

[0010] In this invention, the aquatic plants are selected from salt-tolerant and easy-to-cultivate plants, and the aquatic animals mainly play a role in maintaining the long-term operation of the entire ecosystem. They can regulate the aquatic ecosystem through osmosis and metabolism, and maintain the stability of the aquatic ecosystem.

[0011] In this invention, the submerged plant community includes at least two combinations of Myriophyllum spicatum, Elodea, and Ceratophyllum demersum; the floating plant is Duckweed, which has strong stress resistance and can adapt to the complex ecological environment of saline-alkali land. It has a simple structure with only leaf-like thallus structures, which can absorb nutrients and organic matter in the water through the thallus, reduce the salt content in the water, alleviate eutrophication, and improve water quality.

[0012] In this invention, the planting area ratio of submerged plants to floating plants is 2:1 to 3:1; the stocking density of grass carp is 1-2 fish per cubic decimeter of water, and the grass carp play a role in stirring and promoting the diffusion of salt in the whole system.

[0013] The present invention also includes emergent plants, which are selected from at least one of reeds, calamus, Suaeda salsa, Phragmites communis, Typha or iris.

[0014] This invention also includes silt and sand, which are used to cultivate emergent plants.

[0015] In this invention, the salt content (total dissolved solids, TDS) of the high-salt wastewater is between 1000 mg / L and 2000 mg / L.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention creates an aquatic ecosystem by placing cleaned aquatic plants and animals in salt solutions of varying concentrations and cultivating them under suitable light and temperature conditions. It utilizes the natural salt removal mechanism of aquatic organisms to treat high-salt wastewater. This invention is applicable to ecological restoration and wastewater treatment in saline environments of varying concentrations and has advantages such as low technical cost, no pollution, and strong sustainability, providing a theoretical basis and practical reference for further promotion and application.

[0017] Aquatic plants primarily remove salt from water by absorbing, storing, and transferring ions. Submerged and emergent plants absorb and store salt ions through their roots, regulating salt concentration through osmosis and diffusion. Floating plants reduce salt concentration through growth and metabolism. Aquatic animals also assist aquatic plants in salt removal to some extent. In this invention, the growth process of aquatic plants and animals follows a natural cycle. The salt concentration in the water is effectively reduced through absorption and metabolism by aquatic organisms. This effectively utilizes the natural removal mechanisms within the aquatic ecosystem, achieving a certain degree of salt removal. It is environmentally friendly and can be extended to water bodies with excessive salt content. In such cases, the introduction of aquatic plants and animals can remove salt to some extent, offering advantages such as low cost, reduced ecological damage, increased biodiversity, and environmental protection. Attached Figure Description

[0018] Figure 1 A schematic diagram illustrating the overall trend of salt concentration changes in the same aquatic ecosystem.

[0019] Figure 2 A schematic diagram illustrating the overall trend of salt concentration changes in different aquatic ecosystems. Detailed Implementation

[0020] This invention provides an aquatic ecosystem for treating high-salinity wastewater, the construction method of which includes the following steps: Step 1, Selection of aquatic plants and animals: Select submerged plants such as Myriophyllum spicatum ( Myrtle whorled ), Elodea ( Hydrilla verticillata ), goldfish algae ( Ceratophyllum submersum ) and floating plants duckweed ( Lemna minor A total of 4 kinds of aquatic plants and grass carp ( Ctenopharyngodon idella One type of aquatic animal was used as a material for constructing aquatic ecosystem devices.

[0021] Step 2: Preparation of saline solutions: Prepare salt solutions of different concentrations (800 mg / L, 1200 mg / L, 1400 mg / L, 1600 mg / L, 1700 mg / L, and 1800 mg / L) by mixing calcium sulfate (CaSO4), magnesium chloride (MgCl2), sodium chloride (NaCl), and potassium sulfate (K2SO4) in a mass ratio of 3:3:2:2. High-salinity wastewater typically contains Cl... - SO4 2- Na + Ca 2+ Mg 2+ The present invention uses soluble inorganic salt ions, etc., to prepare the above-mentioned saline body for simulating a high-salt-high-salt wastewater system.

[0022] Step 3: Select plants that are growing well and are similar in size and length, wash them with tap water, and then place them in a 5L transparent ecological box for hydroponic experiment. Design an aquatic ecosystem. Select Myriophyllum spicatum, Ceratophyllum demersum, Duckweed, and Hydrilla verticillata as aquatic plants and grass carp as aquatic animals. The planting area ratio of submerged plants to floating plants is (2-3):1, and the fish stocking density is 1-2 fish per cubic decimeter of water.

[0023] Step 4: Set up aquatic ecosystems with different salt concentrations. Pour solutions of varying salt concentrations into a 5L ecosystem tank, mark the initial water level, label and record the concentration, and then place aquatic plants and animals in the tank for cultivation.

[0024] Step 5: Cultivate at room temperature with good lighting. If the lighting is poor, an LED supplemental lighting system is provided on top.

[0025] Step 6: Periodically sample and test the salt content. The salt content is determined by the gravimetric method (HJ / T 51-1999). First, evaporating dish is dried in an oven at 105.0℃ for 2 hours until constant weight is reached. Weigh and record the data (W0). Then, filter 50ml of water sample with filter paper, place it in an evaporating dish, heat it in a water bath to evaporate the water, and then place it in an oven at 105.0℃ for 2 hours until constant weight is reached. Weigh and record the data (W). Calculate the salt content (C) in the water according to the formula.

[0026] Example 1

[0027] Setting different salt concentrations in the same aquatic ecosystem 3L of solutions with salt concentrations of 800mg / L, 1200mg / L, 1400mg / L, 1600mg / L, and 1800mg / L were injected into five 5L ecospheres. The initial water level was marked and labeled A, B, C, D, and E in order of increasing concentration, as shown in Table 1. The concentrations were recorded and labeled. Then, the aquatic plants and animals were placed in the ecospheres for cultivation according to Table 2 (aquatic plants and animals provided in one ecosphere).

[0028] Table 1. Corresponding initial salt concentrations for each group Table 1 Corresponding initial salt concentrations in each group

[0029] Table 2. Species and quantities of aquatic plants and animals in the experiment. Table 2 Species and quantities of experimental aquatic plants andanimals

[0030] like Figure 1 As shown, this is a schematic diagram illustrating the overall trend of salt concentration changes in the same aquatic ecosystem. In environments with high salinity, the established aquatic ecosystem exhibits a certain degree of salt removal effectiveness. The removal results are as follows... Figure 1 As shown, the salt removal rates of aquatic ecosystems A, B, C, D, and E were 30%, 20%, 17.14%, 15%, and 14.44%, respectively. Aquatic plants adapt to saline environments by regulating the opening and closing of their stomata to reduce water evaporation and salt absorption. Furthermore, aquatic plants also possess the ability to regulate cell membrane permeability to adapt to high-salt environments. Aquatic animals produce a certain amount of waste during metabolism, including salts and inorganic substances. By excreting these wastes, aquatic animals can effectively reduce the salt concentration in the water. This process enables aquatic animals to maintain their internal salt balance and promotes salinity regulation in the water.

[0031] Example 2

[0032] Setting the same salt concentration for different aquatic ecosystems Five 5L ecospheres were filled with 3L of a 1700mg / L salt solution, and the initial water level was marked as group a, b, c, d, and e. Aquatic plants and animals were then placed in the ecospheres for cultivation according to Table 3, and the data were recorded. These five ecospheres simulated different ecosystems to explore the effects of different aquatic ecosystems on salt removal.

[0033] Table 3. Components of different aquatic ecosystems Table 3The components of different ecosystems

[0034] like Figure 2 The diagram shows the overall trend of salt concentration changes in different aquatic ecosystems. The results indicate that all ecosystems have some effect on salt removal, but this effect varies significantly at different stages. Taking day 15 of the experiment as the dividing line, the changes in salt removal effectiveness before and after the experiment are quite obvious. In the early stage, group b showed the most significant effect, followed by group e. In both groups, *Myriophyllum spicatum* exhibited strong salt tolerance, showing no significant change in the early stage but a significant decrease in salt concentration in the later stage. When using aquatic plants to remediate water pollution, *Ceratophyllum demersum*, duckweed, *Hydrilla verticillata*, and a small number of fish can be selected as initial choices. In the later stage of the experiment, groups a and e showed the same decreasing trend, and the same aquatic plants were placed in the ecosystem boxes.

Claims

1. An aquatic ecosystem for treating high-salinity wastewater, comprising aquatic animals and aquatic plants, characterized in that, have: At least two submerged plants; at least one floating plant; at least one aquatic animal; wherein: The submerged plants are selected from at least two combinations of Myriophyllum spicatum, Hydrilla verticillata, Ceratophyllum demersum, Salicornia glutinosa, Portulaca oleracea, Potamogeton pectinatus, or Lysimachia christinae. The floating plants are selected from at least one of water hyacinth, water lily, duckweed, water lily, or fern-like azolla. The aquatic animal in question is a grass carp.

2. The aquatic ecosystem for treating high-salinity wastewater according to claim 1, characterized in that, The submerged plant community includes at least two combinations of Myriophyllum spicatum, Hydrilla verticillata, and Ceratophyllum demersum, and the floating plant is Duckweed.

3. The aquatic ecosystem for treating high-salinity wastewater according to claim 1, characterized in that, The planting area ratio of submerged plants to floating plants is 2:1 to 3:1, and the stocking density of grass carp is 1-2 fish per cubic decimeter of water.

4. The aquatic ecosystem for treating high-salinity wastewater according to claim 1, characterized in that, It also includes emergent plants, which are selected from at least one of reeds, calamus, Suaeda salsa, Phragmites australis, Typha or iris.

5. The aquatic ecosystem for treating high-salinity wastewater according to claim 4, characterized in that, It also includes silt and sand, used to cultivate emergent plants.

6. The aquatic ecosystem for treating high-salinity wastewater according to claim 1, characterized in that, The salt content of high-salinity wastewater is between 1000 mg / L and 2000 mg / L.

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