Detailed Description
The technical scheme in the embodiment of the invention is clearly and completely described below in combination with the specific content of the invention; it will be apparent that the described embodiments are only some embodiments of the invention, but not all embodiments, which do not constitute limitations of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
The terms that may be used herein will first be described as follows:
the term "and/or" is intended to mean that either or both may be implemented, e.g., X and/or Y are intended to include both the cases of "X" or "Y" and the cases of "X and Y".
The terms "comprises," "comprising," "includes," "including," "has," "having" or other similar referents are to be construed to cover a non-exclusive inclusion. For example: including a particular feature (e.g., a starting material, component, ingredient, carrier, formulation, material, dimension, part, means, mechanism, apparatus, step, procedure, method, reaction condition, processing condition, parameter, algorithm, signal, data, product or article of manufacture, etc.), should be construed as including not only a particular feature but also other features known in the art that are not explicitly recited.
The term "consisting of … …" is meant to exclude any technical feature element not explicitly listed. If such term is used in a claim, the term will cause the claim to be closed, such that it does not include technical features other than those specifically listed, except for conventional impurities associated therewith. If the term is intended to appear in only a clause of a claim, it is intended to limit only the elements explicitly recited in that clause, and the elements recited in other clauses are not excluded from the overall claim.
The term "parts by mass" means a mass ratio relationship between a plurality of components, for example: if the X component is described as X parts by mass and the Y component is described as Y parts by mass, the mass ratio of the X component to the Y component is expressed as x:y;1 part by mass may represent any mass, for example: 1 part by mass may be expressed as 1kg or 3.1415926 kg. The sum of the mass parts of all the components is not necessarily 100 parts, and may be more than 100 parts, less than 100 parts, or 100 parts or equal. The parts, proportions and percentages described herein are by mass unless otherwise indicated.
Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured," and the like should be construed broadly to include, for example: the connecting device can be fixedly connected, detachably connected or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms herein above will be understood by those of ordinary skill in the art as the case may be.
When concentrations, temperatures, pressures, dimensions, or other parameters are expressed as a range of values, the range is to be understood as specifically disclosing all ranges formed from any pair of upper and lower values within the range of values, regardless of whether ranges are explicitly recited; for example, if a numerical range of "2 to 8" is recited, that numerical range should be interpreted to include the ranges of "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", and the like. Unless otherwise indicated, numerical ranges recited herein include both their endpoints and all integers and fractions within the numerical range.
The terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," etc. refer to an orientation or positional relationship based on that shown in the drawings, merely for ease of description and to simplify the description, and do not explicitly or implicitly indicate that the apparatus or element in question must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present disclosure.
The bacteria-rich porous denitrification filler and the preparation method thereof provided by the invention are described in detail below. What is not described in detail in the embodiments of the present invention belongs to the prior art known to those skilled in the art. The specific conditions are not noted in the examples of the present invention and are carried out according to the conditions conventional in the art or suggested by the manufacturer. The reagents or apparatus used in the examples of the present invention were conventional products commercially available without the manufacturer's knowledge.
As shown in FIG. 1, the embodiment of the invention provides a bacteria-rich porous denitrification filler, which is a filler with water absorption rate of more than 30% formed by immobilizing denitrification bacteria on a particle porous carrier with porosity of more than 90%.
In the denitrification filler, the granular porous carrier is prepared by uniformly mixing tourmaline powder, kaolin, magnesia clay, diatomite, corn straw powder, sodium silicate and sodium bicarbonate with water to prepare granules with the diameter of 8-10 mm, and then preheating and calcining the granules in sequence. Preferably, the preheating temperature of the particles is 400-500 ℃ and the preheating time is 30min; calcining the particles at 1000-1100 ℃ for 120min.
The granule porous carrier comprises the following raw materials in percentage by mass: tourmaline powder 10%, kaolin 20%, magnesia clay 40%, diatomite 10%, corn stalk powder 10%, sodium silicate 8% and sodium bicarbonate 2%.
The corn stalk powder is obtained by crushing corn stalk and sieving with 100 mesh sieve. The corn stalk powder as biological pore forming agent can raise the porosity of porous carrier, and has low cost and easy obtaining of material.
The embodiment of the invention also provides a preparation method of the bacteria-rich porous denitrification filler, which is used for preparing the bacteria-rich porous denitrification filler and comprises the following steps:
step 1, preparing a particle porous carrier: adding water into tourmaline powder, kaolin, magnesia clay, diatomite, corn stalk powder, sodium silicate and sodium bicarbonate, mixing uniformly, granulating, and granulating; preheating and calcining the particles in sequence; calcining and cooling to obtain a granular porous carrier;
step 2, preparing denitrifying bacteria fermentation liquid: inoculating the cryopreserved denitrifying bacteria strain on a solid culture medium for activation, and culturing at constant temperature until single colony grows; picking the activated denitrifying bacteria single colony, and inoculating the single colony into a liquid culture medium to obtain seed liquid; inoculating the seed liquid into a liquid culture medium to obtain denitrifying bacteria fermentation liquor;
step 3, fixing denitrifying bacteria to the particle porous carrier: putting the porous carrier obtained in the step 1 into the denitrifying bacteria fermentation liquid obtained in the step 2, and adsorbing the bacteria liquid until the bacteria liquid is saturated; and (5) performing air drying treatment to obtain the bacteria-rich porous denitrification filler.
In the step 1 of the method, the diameter of the prepared particles is 8-10 mm, and the water absorption rate is more than 30%;
the granule porous carrier comprises the following raw materials in percentage by mass:
tourmaline powder 10%, kaolin 20%, magnesia clay 40%, diatomite 10%, corn stalk powder 10%, sodium silicate 8% and sodium bicarbonate 2%.
The corn stalk powder is obtained by crushing corn stalk and sieving with 100 mesh sieve.
In the step 1 of the method, the preheating temperature of the particles is 400-500 ℃ and the preheating time is 30min;
calcining the particles at 1000-1100 ℃ for 120min.
In the step 2 of the method, denitrifying bacteria strains are stored in a refrigerator or freezer at the temperature of minus 80 ℃ in a freezing way;
the temperature of the constant temperature culture was 30 ℃.
In the step 2 of the method, inoculating into a liquid culture medium, and culturing for 24 hours at 30 ℃ and 150r/min to obtain seed liquid;
inoculating the seed liquid into a liquid culture medium according to the volume ratio of 3%, and culturing for 24 hours at the temperature of 30 ℃ and the speed of 150r/min to obtain denitrifying bacteria fermentation liquor.
In the step 2 of the method, the solid culture medium contains 1% of tryptone, 0.5% of yeast extract powder, 1% of sodium chloride and 1.8% of agar powder according to the mass ratio; adjusting the pH value to 6.8-7.2, and sterilizing for 20min at 121 ℃;
the liquid culture medium contains 1% of tryptone, 1% of yeast extract powder, 0.5% of sodium chloride and 1% of liquid filling amount 60% according to the mass ratio, the pH value is regulated to 6.8-7.2, and then the liquid culture medium is sterilized at 121 ℃ for 20min.
In the step 3 of the method, the air drying treatment is to air-dry for 2-3 hours at 45-50 ℃.
In summary, the bacteria-rich porous denitrification filler combines the immobilized microorganism technology and the denitrification filler technology, and the denitrifying bacteria are immobilized on the porous carrier with the porosity of more than 90% through high-temperature calcination, thus the bacteria-rich porous denitrification filler belongs to the adsorption immobilized microorganism technology, and has the advantages of high porosity, large specific surface area, high biological activity, uniform and dense porous structure, capability of providing perfect habitat and attachment points for the denitrifying bacteria, and good binding force and stability. The filler is applied to the denitrification biological filter, and can be used for rapidly playing a role and has strong stability because a large amount of denitrification bacteria are fixed on the filler, so that the film forming time is saved, the denitrification rate in the reactor can be effectively improved, the treatment capacity of the reactor is enhanced, and the filler has important significance for improving the problem that the total nitrogen of a sewage treatment plant does not reach the standard.
In order to clearly show the technical scheme and the technical effects provided by the invention, the bacteria-rich porous denitrification filler and the preparation method thereof provided by the embodiment of the invention are described in detail in the following by specific embodiments.
Example 1
The embodiment of the invention provides a bacteria-rich porous denitrification filler, which is a granular filler formed by immobilizing denitrifying bacteria on a granular porous carrier, wherein the porosity of the granular filler is more than 90%, and the water absorption rate is more than 30%. The bacteria-enriched porous denitrification filler is prepared by the following steps (see figure 1):
step 1, preparing a particle porous carrier: a1. according to the mass ratio, adding water into 10% tourmaline powder, 20% kaolin, 40% magnesia clay, 10% diatomite, 10% corn stalk powder, 8% sodium silicate and 2% sodium bicarbonate, uniformly mixing, granulating, and the particle size is 8-10 mm; b1. preheating the particles at 400-500 ℃ for 30min, and calcining at 1000-1100 ℃ for 120min; c1. discharging from the furnace, cooling to room temperature to obtain the granular porous carrier;
the corn stalk powder is used as a biological pore-forming agent and is obtained by crushing corn stalk and sieving the crushed corn stalk with a 100-mesh sieve. Because the corn stalk is simple and easy to obtain and low in cost, the powder can effectively improve the porosity of the granular porous carrier and reduce the preparation cost.
Step 2, preparation of denitrifying bacteria fermentation liquid: a2. dipping a denitrifying bacterial strain which is environment-friendly and stored in a refrigerator at-80 ℃, inoculating the denitrifying bacterial strain on a solid culture medium for activation, and culturing at the constant temperature of 30 ℃ until a single colony is grown; b2. picking an activated denitrifying bacteria single colony, inoculating the single colony into a liquid culture medium, and culturing for 24 hours at 30 ℃ and 150r/min, wherein the single colony is seed liquid; c2. inoculating the seed solution into a liquid culture medium according to the volume ratio of 3%, and culturing for 24 hours at the temperature of 30 ℃ at the speed of 150r/min to obtain denitrifying bacteria fermentation liquor.
In the step 2, the solid culture medium comprises (by volume ratio): 1% of tryptone, 0.5% of yeast extract powder, 1% of sodium chloride and 1.8% of agar powder, adjusting pH value to 6.8-7.2 before digestion, and sterilizing for 20min at 121 ℃.
The liquid culture medium comprises the following components in percentage by volume: 1% of tryptone, 0.5% of yeast extract, 1% of sodium chloride, 60% of liquid loading, 6.8-7.2 of pH value before digestion, and sterilization at 121 ℃ for 20min.
Step 3, fixing denitrifying bacteria to the particle porous carrier: a3, putting the porous carrier in the step 1 into the denitrifying bacteria fermentation liquid in the step 2, and adsorbing the bacteria liquid until the bacteria liquid is saturated; b3 Air-drying at 45-50deg.C for 2-3h to obtain the final product.
The application of the prepared bacteria-rich porous denitrification filler is as follows: the bacteria-rich porous denitrification filler is filled into an upflow denitrification biological filter, the filling ratio is 50-60%, and the hydraulic retention time is 1.5-2 h.
Compared with the prior art, the invention has the following positive effects:
(1) The particle porous carrier is mainly formed by sintering natural mineral materials at high temperature, and has high mechanical strength and is not easy to damage in the practical application process. The carrier uses 100-mesh corn straw and sodium bicarbonate as pore-forming agents, has fluffy structure after calcination, has uniform and dense porous structure on the surface and inside, has porosity up to more than 90%, water absorption rate up to more than 30%, can adsorb a large amount of denitrifying bacteria and prevent bacterial loss, and effectively fixes the denitrifying bacteria, thus having high bioactivity. The carrier has high porosity and large specific surface area, so that the contact area with sewage can be increased, and the treatment capacity is improved.
(2) The porous carrier adsorbs bacteria liquid and then is subjected to air drying treatment at 45-50 ℃, so that the binding force of denitrifying bacteria and materials can be enhanced, the fixation of denitrifying bacteria is facilitated, the denitrifying bacteria cannot be damaged due to low-temperature drying at 45-50 ℃, and the high biological activity of the filler is reserved.
(3) Compared with the traditional filler, the bacteria-rich porous denitrification filler is applied to the denitrification biological filter, and can rapidly play a role and has strong stability because a large amount of denitrification bacteria are fixed on the filler, so that the film forming time is saved, the denitrification rate in the reactor can be effectively improved, and the treatment capacity of the reactor is enhanced.
(4) The invention combines the immobilized microorganism technology and the denitrification filler technology, is applied to the upflow denitrification biological filter, has a certain technical innovation, and has important significance for improving the problem that the total nitrogen of the sewage treatment plant does not reach the standard.
Example 2:
the bacterial-rich porous denitrification filler prepared by the invention is filled into a simulated reactor of a denitrification biological filter, the filling ratio is 50%, the reactor adopts an upflow water inlet mode, the water inlet is domestic sewage with total nitrogen of about 25mg/L, COD of about 100mg/L, and the hydraulic retention time is 1.5h. The total nitrogen removal rate was measured by sampling every 24 hours, and a reactor packed with quartz sand was used as a control (see fig. 2). The experimental result shows that the effluent of the reactor filled with the bacteria-rich porous denitrification filler is stable for 3 days, the total nitrogen removal rate is always kept high, the total nitrogen removal rate in the early stage of the control group is quite low, the total nitrogen removal rate gradually rises along with the operation of the reactor, and the total nitrogen removal rate is stable after 15 days of operation. Running to the 30 th day, the total nitrogen removal rate of the reactor effluent filled with the bacteria-rich porous denitrification filler is 95.96%, which is far higher than 73.76% of that of the control group. Therefore, the bacteria-rich porous denitrification filler can effectively fix denitrifying bacteria and keep higher activity, so that the film forming time is saved, the denitrification efficiency of the reactor is improved, and the treatment capacity of the reactor is enhanced.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims. The information disclosed in the background section herein is only for enhancement of understanding of the general background of the invention and is not to be taken as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art.