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CN-119954303-B - Straw-based biological membrane carrier and preparation method and application thereof

CN119954303BCN 119954303 BCN119954303 BCN 119954303BCN-119954303-B

Abstract

The invention relates to the technical field of sewage treatment. More particularly, the invention relates to a straw-based biomembrane carrier, a preparation method and application thereof. The invention provides a straw-based biomembrane carrier and a preparation method thereof, and crop straws are used as a film carrier to construct an algae-bacteria symbiotic system and applied to aquaculture tail water treatment. The straw can be used as a carrier filler for microalgae and bacteria growth on one hand, and can slowly release organic matters as a carbon source for microorganism growth attached to the organic matters in the degradation process on the other hand. The microalgae photosynthesis can provide oxygen for aerobic bacteria, aeration is not needed when the cultivation tail water is treated, the aged biological film on the straw is periodically peeled off by utilizing the impact of water flow and collected as fish bait, and the organic matters, nitrogen, phosphorus and other nutrient elements in the cultivation tail water can be recycled when the cultivation tail water is treated.

Inventors

  • LI BINGTANG
  • LI JIANFEN
  • ZHU PENGHUI
  • QIN ZHENHUA
  • ZHANG JING
  • SHEN WENJUAN

Assignees

  • 武汉轻工大学

Dates

Publication Date
20260508
Application Date
20250225

Claims (10)

  1. 1. The preparation method of the straw-based biomembrane carrier is characterized by comprising the following steps of: S1, weaving straws into a net-shaped straw braided fabric, and continuously processing the net-shaped straw braided fabric, wherein the following steps are as follows: S1.1, uniformly spraying sodium carboxymethyl cellulose solution with the mass concentration of 0.5-1.0% on the surface of the straw braided fabric until the surface of the straw braided fabric is wet, uniformly spraying wheat flour on the surface of the straw braided fabric, and airing for later use; s1.2, uniformly spraying a polyvinyl alcohol solution with the mass concentration of 5% on the surface of the dried straw braided fabric, uniformly spraying a CaCl 2 solution with the mass concentration of 3-5% on the surface of the dried straw braided fabric after the dried straw braided fabric is dried, and then uniformly spraying a sodium alginate solution with the mass concentration of 5-10% on the surface of the straw braided fabric; S1.3, uniformly spraying biochar powder on the surface of the straw braided fabric when the straw braided fabric is dried to be semi-dry and a layer of transparent film is formed on the surface of the straw braided fabric, spraying Fe (NO 3 ) 3 solution with the mass concentration of 2-3% on the surface of the straw braided fabric after the surface of the straw braided fabric is dried, spraying ammonia water with the mass concentration of 3-5%, and naturally drying; s2, inoculating the denitrified flocculent sludge acclimatized with the activated sludge and the bottom sludge of the fish pond into a denitrifying and expanding culture device for expanding culture, and after expanding culture for 5 days, placing the straw braided fabric treated in the S1 into the denitrifying and expanding culture device for culturing for 10 days until flocculent biomembrane grows on the surface of the straw braided fabric, so as to finish bacterial biomembrane formation; And S3, after bacterial biofilm formation is completed, adding microalgae algae liquid and BG11 culture liquid into the denitrification and expanding culture device, and culturing for 5-7 days, and obtaining the straw-based biofilm carrier after microalgae are fully distributed on the surfaces of straw.
  2. 2. The method for preparing a straw-based biomembrane carrier as claimed in claim 1, wherein the straw used in S1 is pretreated, specifically: Adding 0.5-1% of quicklime and 0.2-0.5% of sodium chloride into water, stirring uniformly, soaking the straws in the cleaned straws for 24 hours, taking out the straws, airing, putting the straws into a sodium sulfite solution with the mass concentration of 0.2-0.5%, continuously soaking for 24 hours, taking out, airing for standby.
  3. 3. The method for preparing the straw-based biomembrane carrier as claimed in claim 1, wherein the method for preparing the biochar powder used for spraying in the step S1.3 is as follows: Crushing wheat straw or corn straw, sieving with a 100-mesh sieve, soaking in FeCl 3 solution with mass concentration of 5% for 48h, and heating at 400-500 ℃ for 2h while isolating air to obtain the biochar powder.
  4. 4. The preparation method of the straw-based biomembrane carrier as claimed in claim 1, wherein in the S2, denitrified flocculent sludge and pond sediment after acclimation of the activated sludge are inoculated into a denitrifying and expanding culture device, and the expanding culture is carried out under the conditions that COD is 2000mg/L, nitrate nitrogen is 200mg/L, total phosphorus is 20mg/L, the mass concentration of dissolved oxygen is 0.2-0.5mg/L, pH is 6.5-7.5 and the culture temperature is controlled to be 25-35 ℃.
  5. 5. The method for preparing a straw-based biomembrane carrier as claimed in claim 1, wherein after adding microalgae liquid and BG11 culture liquid into a denitrification expander in S3, culturing under the conditions of illumination intensity of 2000-3000Lux, temperature of 25-30 ℃ and light-dark ratio of 12/12.
  6. 6. A straw-based biofilm carrier prepared by the preparation method of any one of claims 1 to 5.
  7. 7. A method for treating the tail water of cultivation by adopting the straw-based biomembrane carrier as claimed in claim 6, which is characterized by comprising the following steps: Taking a rectangular water tank with the depth of 2.0-4.0m as a tail water treatment area, arranging a plurality of anti-fouling curtains in the tail water treatment area at intervals along the length direction of the tail water treatment area, dividing the tail water treatment area into a plurality of strip areas with the width of 2.0-3.0 m so as to enable water flow in the tail water treatment area to flow in an S shape, and respectively arranging a water inlet and a water outlet at two ends of the water flow direction; Step two, arranging a plurality of straw-based biomembrane carriers at intervals of 2.0-3.0m along the width direction of the tail water treatment area in the strip-shaped area, wherein the straw-based biomembrane carriers are immersed into 5-10cm below the water surface; And thirdly, sequentially precipitating and filtering the culture tail water in the fish pond, discharging the tail water into the tail water treatment area from the water inlet, treating for 48-96 hours, and then returning the treated tail water to the fish pond.
  8. 8. The method for treating a cultivation tail water of a straw-based bio-film carrier according to claim 7, further comprising the steps of: Acquiring ammonia nitrogen concentration, total nitrogen concentration and total phosphorus concentration in tail water through a water quality on-line monitoring device arranged at the water outlet, and presetting standard reaching thresholds of the ammonia nitrogen concentration, the total nitrogen concentration and the total phosphorus concentration: When the ammonia nitrogen concentration, the total nitrogen concentration and the total phosphorus concentration of the tail water are all lower than the corresponding standard reaching thresholds, the treated tail water is sent back to the fishpond; and stopping sending the treated tail water back to the fishpond when at least one of the ammonia nitrogen concentration, the total nitrogen concentration and the total phosphorus concentration of the tail water is not lower than the corresponding standard reaching threshold value, and sending the treated tail water to the water inlet to enable the treated tail water to reenter the tail water treatment area for treatment.
  9. 9. The method for treating a cultivation tail water of a straw-based bio-film carrier according to claim 8, further comprising the steps of: Fifthly, discharging water in the tail water treatment area to 1/2 of the pool volume every 30 days, simultaneously adjusting the inflow velocity of water at the water inlet by 2-3 times, impacting and peeling mature and aged straw-based biomembrane carriers in the tail water treatment area through water flow, collecting the peeled straw-based biomembrane carriers through blow-down pipes at two sides of the tail water treatment area, and then sterilizing, dehydrating and drying to obtain fish bait.
  10. 10. A cultivation tail water treatment system adopting the cultivation tail water treatment method as claimed in any one of claims 7 to 9, comprising: the tail water treatment tank is provided with a water inlet and a water outlet; the plurality of anti-fouling curtains are arranged in the tail water treatment tank at intervals along the length direction of the tail water treatment tank, the interior of the tail water treatment tank is divided into a plurality of strip-shaped areas, so that water flow in the tail water treatment tank flows in an S shape, and the water inlet and the water outlet are respectively positioned at two ends of the water flow direction; The strip-shaped area is internally provided with a plurality of straw-based biomembrane carriers at intervals along the width direction of the tail water treatment tank; the water quality on-line monitoring device is arranged in the tail water treatment tank and is close to the water outlet; One end of the water outlet pipe is connected with the water outlet, and a valve is arranged on the water outlet pipe; the two ends of the drain pipe are respectively connected with the water inlet and the water outlet pipe; A water pump provided on the drain pipe; and the sewage discharge pipe is arranged in the tail water treatment tank.

Description

Straw-based biological membrane carrier and preparation method and application thereof Technical Field The invention relates to the technical field of sewage treatment. More particularly, the invention relates to a straw-based biomembrane carrier, a preparation method and application thereof. Background China is a large country of aquaculture, and has large aquaculture area, high yield and multiple aquaculture types. In recent years, with the rapid development of high-density aquaculture modes, ecological environmental problems caused by the discharge of aquaculture tail water are more and more prominent. The culture tail water refers to waste water containing pollutants such as waste, culture residues, feces, feed residues, culture medicines and the like generated in the aquaculture process or after the aquaculture is finished. The excessive nutrient substances such as nitrogen, phosphorus and the like in the culture tail water can cause eutrophication of surrounding natural water areas, and seriously affect the functions of surrounding ecological environments. High concentrations of ammonia nitrogen and nitrite can damage the tissue structure, physiological characteristics and metabolic capacity of the farmed subjects, thereby leading to massive death of the aquatic products. Traditional cultivation tail water treatment technology mainly comprises physical, chemical and biological treatment methods, wherein the physical and chemical methods such as adsorption filtration, flocculation precipitation, ozone oxidation and the like play an important role in water body restoration, but the use of the methods is limited by high energy consumption, excessive waste sludge and large amount of greenhouse gas emission. In contrast, biological treatment technology utilizes the metabolic capability of microorganisms or autotrophs to convert pollutants into energy, so that not only is the emission of pollutants reduced, but also the possibility of repairing a damaged ecological system is provided, and the advantages of environmental friendliness, safety and low toxicity are presented. In general, nitrogen removal by microorganisms is a relatively economical means, and the microorganisms eventually convert organic nitrogen in water to nitrogen for removal by nitrification and denitrification. Denitrifying bacteria play an important role in the biological denitrification process, the bacteria are usually heterotrophic organisms, the denitrification needs a sufficient organic carbon source, however, the concentration of organic matters in the culture tail water is usually low, COD is between 20mg/L and 100mg/L, the denitrification requirements of the denitrifying bacteria cannot be met, and the biological denitrification efficiency of the culture tail water is low. Microalgae are a single-cell microorganism which can grow rapidly, has simple nutrition requirements and is easy to culture. The microalgae takes light as an energy source, absorbs elements such as carbon, nitrogen, phosphorus and the like in the culture tail water to provide nutrients for the microalgae, can effectively remove pollutants such as nitrogen, phosphorus and the like, and further realizes resource utilization. Although microalgae have strong absorption and assimilation capacities on nitrogen and phosphorus pollutants in the culture tail water, the simple utilization of the microalgae for treating the tail water is difficult to obtain good effects, on one hand, the microalgae are suspended in the water, so that the microalgae are easy to be swallowed by filter feeding aquatic organisms to reduce the quantity, and meanwhile, the microalgae suspended in the water possibly cause secondary pollution after entering a natural water body, and on the other hand, the autotrophic microalgae have weaker organic matter removal effect than bacteria, and the influence of external environments such as illumination on the removal of the nitrogen and phosphorus pollutants is also larger, so that the microalgae are difficult to obtain good effects when the microalgae are singly treated in the culture tail water. The algae-bacteria symbiota combines the advantages of algae and bacteria in bioremediation, such as large surface area, easy culture, low propagation cost and the like, and in the algae-bacteria symbiotic system, the synergistic effect of the microalgae and the bacteria plays a great role in removing pollutants in water. The microalgae can utilize CO 2 released by bacteria as an important carbon source for growth, and can provide O 2, inorganic nutritive salt and various organic substances for the bacteria, so that the inhibition of insufficient carbon source in the culture tail water to denitrification is relieved to a certain extent. Because the effluent quality of the suspended algae-bacteria symbiotic system is easily influenced by suspended microalgae and bacteria, the suspended microalgae and bacteria are difficult to separate and harvest, the hydraulic