CN109089852B - Method for cultivating plants in algae-based flooding manner for wastewater treatment - Google Patents

Abstract

The invention provides a method for cultivating plants in an algae-based flooding way for wastewater treatment, which is characterized in that microalgae are inoculated in wastewater, a high-oxygen water environment is created by oxygen released by photosynthesis of the microalgae, and then the plants are directly put into a cultivation container, so that the overground parts of the plants are submerged in water for cultivation. The method can relieve the stress of the flooding on the plants, and the plants can still grow under the flooding condition. The flooding cultivation method does not need to fix plants, greatly simplifies the cultivation, management and harvest of the plants, and can cultivate the plants in the wastewater at high density, thereby improving the ecological restoration efficiency of the wastewater. The invention is helpful to promote the engineering application of plants in wastewater remediation and the water culture production of crops.

Description

Method for cultivating plants in algae-based flooding manner for wastewater treatment

Technical Field

The invention belongs to the field of plant flooding cultivation, and particularly relates to an algae-based flooding cultivation method for wastewater treatment.

Background

The water culture system has the advantages of small influence of environmental factors, convenience for system regulation and control, difficulty in infecting soil to plant common plant diseases and insect pests and the like. As hydroponic crops are significantly higher in both yield and quality than soil-planted crops, the demand for large-scale hydroponic cultivation in the agricultural market has increased year by year. The agricultural large-scale hydroponic market has expanded about 5-fold over the last 10 years, with a total of about 80 billion dollars in global economic value at present. In addition, hydroponic techniques are now used for the ecological remediation of a wide variety of waste waters. The key step of water planting is the field planting of crops, namely fixing the stem base of a plant by using a foam plate or winding the plant by using sponge strips/non-woven fabrics so as to control the water penetration depth of the plant. The main problems of the method are as follows: 1. the fixation of crops is time-consuming and labor-consuming, and the root systems of the crops are easily damaged; 2. the crops are not firmly fixed, so that the management difficulty is increased; 3. not beneficial to transplanting, managing and harvesting; 4. when plants are used for wastewater remediation, high-density cultivation helps to improve the remediation efficiency, and planting limits the cultivation density of the plants.

However, if the floating plants are directly flooded, the flooding stress will severely inhibit the growth of the crops, and the crops will be difficult to survive. When the plant is in a flooded state, the root system and the overground part of the plant are anoxic, and anaerobic respiration is generated, so that high-concentration ethylene and other harmful substances (hydrogen sulfide, acetic acid, butyric acid and the like) are generated, and the growth of the crops is severely inhibited; the content of Malondialdehyde (MDA) in leaves is increased, so that the selective absorption function of cell membranes is lost and intracellular electrolyte is leaked, and various physiological activities of plants are influenced; meanwhile, ethanol, acetaldehyde and glucoside generated in plants can destroy the balance of an active oxygen metabolic system in the plants, the activity of superoxide dismutase (SOD) and other protective enzymes is reduced, a large number of free radicals are generated, chloroplast degradation is caused, crop photosynthesis is inhibited, the leaves are greenish, yellow and withered, and the plants die in severe cases.

Disclosure of Invention

The invention aims to provide a method for algae-based submerged cultivation plants for wastewater treatment, aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: a method of algae-based flooded growing plants for wastewater treatment comprising the steps of:

(1) preparing a nutrient solution: diluting the nutrient salt or the wastewater to prepare nutrient solution;

(2) subpackaging nutrient solution: subpackaging the nutrient solution into each cultivation container;

(3) inoculating green algae, namely inoculating the microalgae into the nutrient solution at the concentration of 0.125 g/L;

(4) transplanting plants: directly putting the plants into a cultivation container, and submerging the overground parts of the plants in water;

(5) in the illumination of 180 mu mol m^-2s^-1Culturing is carried out under the conditions that the average temperature is 28.3 ℃ and the relative humidity is 36.7-85.2%.

Further, the nutrient salt or the waste water and water are diluted according to the ratio of 1:3 to prepare nutrient solution.

Further, the volume of the cultivation container is 3L.

Further, the cultivation container is a light-permeable container.

Further, the inoculated algae are green algae screened from the wastewater.

Furthermore, the plants are directly put into the cultivation container during transplanting without fixing, and the overground parts of the partial plants are submerged in water.

The invention has the advantages that: according to the invention, based on the mutual action of species of algae and plants, the algae and the plants are cultured in the same system, carbon dioxide released by the respiration of plant roots promotes the growth and photosynthesis of the algae, and oxygen released by the photosynthesis of the algae fundamentally increases the oxygen content in the nutrient solution, eliminates the stress effect of low oxygen concentration on crops in a flooding state, and promotes the growth of the plant roots, the absorption of nutrients and water and the growth of the crops. The invention has the following beneficial effects: (1) the artificial fixation of crops is not needed, and the direct submerged cultivation is carried out, so that the composition and the operation management of a water culture system are greatly simplified, and the water culture production cost is reduced; (2) can cultivate plants in the wastewater at high density, thereby improving the wastewater remediation efficiency and being beneficial to the engineering application of the plants in the wastewater remediation.

Drawings

FIG. 1 is an iris plant obtained by the cultivation in the examples; the left is the control plant and the right is the experimental plant.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Modifications or substitutions of the methods, steps or conditions of the present invention may be made without departing from the spirit and substance of the invention, and the technical means used in the examples are conventional means known to those skilled in the art unless otherwise specified.

Example (b):

in the embodiment, the green alga-pig raising wastewater culture system is used for cultivating the iris in a flooding way, and nutrient salt can be adopted to replace the wastewater.

(1) Preparing nutrient solution in two groups of culture containers (each group comprises 3 culture containers with the volume of 3L), wherein water is used as solute, and the waste water is diluted according to the proportion of 1:3 to obtain the nutrient solution;

(2) inoculating green algae, screening green algae from wastewater, inoculating the green algae into 3 cultivation containers of experimental group at concentration of 0.125 g/L, and adding no green algae in control group;

(3) transplanting crops: directly placing 18 (plant height is about 54cm) iris tectorum into a cultivation container, wherein the flooding height is 12cm, and transferring 3 plants into each container;

(4) placing the two groups of cultivation containers in 180 mu mol m of light^-2s^-1Culturing at the average temperature of 28.3 deg.C and relative humidity of 36.7-85.2% to obtain plant with flooding height of 12 cm; measuring chlorophyll content of leaves of the water flooded section of the iris at intervals, green alga biomass and NH of a culture solution₄The iris tectorum is obtained after 22 days of culture, as shown in figure 1, the iris tectorum in the experimental group (right picture) has a significantly better growth vigor than that in the control group (left picture), the iris tectorum in the experimental group after flooded culture has an average fresh weight value of 76.0 +/-4.3 g/plant (N is 3), the iris tectorum in the control group has an average fresh weight value of 48.4 +/-4.7 g/plant (N is 3), the iris tectorum in the experimental group has a chlorophyll content of 48.1 +/-8.6, the iris tectorum in the control group has an average chlorophyll content which gradually decreases to 23.8 +/-15.8 (N is 3) along with the culture time due to the influence of flooding stress, and the average algae cell concentration of the green algae in the experimental group is 1.74 × 10 after the culture is finished⁷M L, waste water NH₄The N concentration is less than 5 mg/L, and the detection result of the microorganism shows that when the culture time is 15 days, all pathogenic bacteria in the culture solution are basically removed, the relative abundance of other microorganisms except a few bacteria is also remarkably reduced, and NH in the control group is reduced₄The N concentration remained high, with an average concentration of 105.9 ± 26.1 mg/L (N ═ 3).

According to the embodiment, based on the mutual interaction of species of algae and crops, the crops are directly submerged and cultivated in a green algae-pig raising wastewater culture system without manual field planting, the algae and the crops are mutually promoted, the damage of flooding stress to the crops is avoided, the composition and the operation management of a water culture system are effectively simplified, and the cost of water culture production is reduced; the method has the advantages of effectively treating the wastewater, harvesting crops and green algae, along with high yield and high economic benefit.

Claims (3)

1. A method of algae-based flooded cultivation of plants for wastewater treatment, comprising the steps of:

(1) preparing a nutrient solution: diluting the pig raising wastewater to prepare nutrient solution;

(2) subpackaging nutrient solution: subpackaging the nutrient solution into each cultivation container, wherein the cultivation container is a light-permeable container;

(3) inoculating green algae, namely inoculating the green algae into the nutrient solution at the concentration of 0.125 g/L, wherein the green algae are obtained from the pig-raising wastewater;

(4) transplanting plants: directly putting the plants into a cultivation container, and submerging the overground parts of the plants in water;

(5) in the illumination of 180 mu mol m^-2s^-1Culturing is carried out under the conditions that the average temperature is 28.3 ℃ and the relative humidity is 36.7-85.2%.

2. The method of claim 1, wherein the swine wastewater is diluted 1:3 with water to form a nutrient solution.

3. The method of claim 1, wherein said cultivating container has a volume of 3L.

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