Sewage treatment microbial carrier based on red mud resource improvement

Abstract

The invention provides a microbial carrier for sewage treatment based on red mud improvement, which is characterized in that the physical structure of red mud with the water content of 40-45% is primarily modified, and then the primarily modified red mud is alkalized by using a sodium hydroxide solution to obtain red mud improvement powder meeting the requirements of the invention; adding sodium carboxymethyl cellulose, spiral shell powder and distillers' grains according to a ratio, uniformly mixing, grinding the mixed material, processing particles by using a traditional Chinese medicine pelleting machine, and naturally airing to obtain the red mud improved microbial carrier for sewage treatment. The invention provides a method for preparing a sewage treatment microbial carrier based on red mud resourceful improvement aiming at the technical problem and the practical problem of upgrading and dilatation of a sewage treatment plant, and can effectively solve the problems of difficulty in water quality standard reaching, difficulty in land acquisition, high construction cost and the like of an old sewage treatment plant.

Description

Technical Field

[0001] The present invention belongs to the field of water pollution prevention and control, and relates to a microbial carrier applied when adopting the technology of upgrading and expanding the standard without land acquisition for rural sewage treatment, urban sewage treatment, industrial sewage treatment and aquaculture tail water treatment. Background Art

[0002] There are many current sewage treatment technologies and processes, and the commonly used ones include the activated sludge method, the oxidation ditch method, membrane treatment, etc. Among them, the activated sludge method has the largest total amount and the widest range. With the continuous increase in the scale of sewage treatment, it is imperative to upgrade and transform sewage treatment plants. The annual upgrade and transformation demand in cities such as Jinan, Qingdao, and Zhengzhou alone exceeds 600,000 tons, and the upgrade and transformation demand in cities such as Shanghai, Suzhou, and Shenzhen exceeds 1 million tons. However, the current sewage treatment plants using the activated sludge method are facing great difficulties such as difficult land acquisition, tight funds, and overly long transformation cycles, which limit the progress of this work. Summary of the Invention

[0003] The purpose of the present invention is to provide a microbial carrier for sewage treatment based on the resource utilization and improvement of red mud. The microbial carrier is a granular filler based on modified red mud, and the upgrade and transformation of sewage treatment plants are realized on the basis of the traditional activated sludge method. To this end, the present invention adopts the following technical solutions:

[0004] A microbial carrier for sewage treatment based on red mud improvement, characterized in that it is prepared by the following method:

[0005] (1) Put red mud with a moisture content of 40%-45% into a ball mill for grinding to preliminarily improve the physical structure of the red mud; then, soak the preliminarily modified red mud with sodium hydroxide solution and then air-dry it naturally to obtain a red mud improvement product;

[0006] (2) Mix the red mud improvement product with sodium carboxymethyl cellulose CMC-Na, snail shell powder, and distiller's grains with a protein content of 15%-20% evenly, then grind the mixed materials, and then process them into 5-8 mm particles by a traditional Chinese medicine pill-making machine, and air-dry them naturally to obtain a microbial carrier for sewage treatment based on red mud improvement.

[0007] On the basis of adopting the above technical solutions, the present invention can also adopt the following further technical solutions, or use a combination of these further technical solutions:

[0008] In step (2), by mass fraction: red mud: 100 parts; sodium carboxymethyl cellulose CMC-Na 4-6 parts; snail shell powder: 9-11 parts; distiller's grains: 9-11 parts.

[0009] The selected red mud has a moisture content of 40%-45%, the total mass of silicon dioxide, iron(III) oxide, and aluminum(III) oxide accounts for no less than 65% of the solid matter, the total mass of calcium oxide and sodium oxide is no higher than 8%, and the titanium content is between 2% and 8%.

[0010] If the calcium oxide content in the selected red mud is greater than 8%, it needs to be soaked in 5% sulfate for more than 24 hours to precipitate calcium ions to meet the performance of red mud during preliminary modification.

[0011] The selected standard for sodium carboxymethyl cellulose CMC-Na is medium-substitution sodium carboxymethyl cellulose with 0.7≤DS≤0.9, or high-substitution sodium carboxymethyl cellulose with DS>0.9. Its grade is food-grade sodium carboxymethyl cellulose, and its property is pure white. The qualified sodium carboxymethyl cellulose CMC-Na is screened through a 200-mesh stainless steel sieve, and the powder under the sieve is selected for standby.

[0012] The snail shell powder is 200 mesh, and the snail shell is one or a mixture of several of Cipangopaludina chinensis, Cipangopaludina carinatus, Bullacta exarata, or Ostrea rivularis shells. The specified amount of snail shell powder is added to a grinder for grinding, with a set rotation speed of 800 r / min and a grinding time of 30 minutes. After grinding, it is screened through a 200-mesh stainless steel sieve, and the powder under the sieve is selected for standby.

[0013] The selected distiller's grains are one of the distiller's grains after brewing liquor with sorghum, corn, or rice as raw materials. The distiller's grains are put into a hot air drying equipment for drying until the moisture content is less than 10%. Then the distiller's grains are put into a grinder, with a set rotation speed of 800 r / min and a grinding time of 30 minutes. After grinding, it is screened through a 200-mesh stainless steel sieve, and the powder under the sieve is selected for standby.

[0014] The preparation method includes the following specific steps:

[0015] 1) Put the red mud with a moisture content of 40%-45% in the specified weight into a ball mill, add steel balls with a diameter of 3-5 mm according to the mass fraction ratio of 100:18 for grinding. Set the rotation speed at 500 r / min and the grinding time at 3 hours. After grinding, it is screened through a 200-mesh sieve made of stainless steel, and the powder under the sieve is selected for standby;

[0016] 2) Put the powder obtained in step 1) into a sodium hydroxide solution with a mass fraction of 10% for soaking. During the soaking process, a stirrer is used for continuous stirring, with a stirring speed greater than 100 revolutions per minute and a soaking time greater than 8 hours. After soaking, it is naturally dried;

[0017] 3) Put the modified red mud powder, snail shell powder, distiller's grains powder, and sodium carboxymethyl cellulose powder into a fully automatic traditional Chinese medicine pill-making machine, set the pill diameter at 6 mm, and set the speed at 500 pills per minute to make a microbial carrier for sewage treatment modified with red mud.

[0018] Red mud is a waste product in the production of aluminum products and a major problem for aluminum mining enterprises. According to statistics, in 2023 alone, the production volume of red mud in China was approximately 107 million tons, and the cumulative stockpile was about 1.1 billion tons. The treatment is extremely difficult. In view of the technical problems and practical difficulties in upgrading and expanding sewage treatment plants, the present invention proposes a microbial carrier based on the resource utilization of mineral waste. Research shows that adding suspended fillers on the basis of the activated sludge process can achieve an 80% expansion capacity without increasing the floor area of the sewage treatment plant, and the effluent index can be improved to the fifth-class surface water level, greatly alleviating the economic and land occupation pressures, and at the same time having better effluent effects. The present invention effectively solves the utilization path of mineral waste, and at the same time solves the technical problems of sewage treatment, and can effectively solve the problems such as difficulty in meeting water quality standards, difficulty in land acquisition, and high construction costs of old sewage treatment plants. Detailed implementation mode

[0019] A microbial carrier for sewage treatment based on red mud improvement provided by the present invention is prepared by the following method:

[0020] Put red mud with a moisture content of 40%-45% into a ball mill, add steel balls accounting for 18% of the total mass of red mud (steel ball diameter 3-5 mm), set the rotation speed at 500 r / min and the grinding time at 3 hours to preliminarily improve the physical structure of the red mud. Subsequently, soak the preliminarily modified red mud with a 10% mass fraction of sodium hydroxide solution for 8 hours, and then air dry naturally to obtain a red mud improvement product meeting the requirements of the invention. Secondly, add sodium carboxymethyl cellulose (CMC-Na) in a mass fraction ratio of 1:20, add ground snail shell powder in a mass fraction ratio of 1:10, and add distiller's grains with a protein content of 15%-20% in a mass fraction ratio of 1:10, and then mix and stir evenly. Then grind the mixed material to 200 mesh, and then process it into 5-8 mm particles by a traditional Chinese medicine pill making machine, and air dry naturally to obtain a microbial carrier for sewage treatment with red mud improvement. By mass fraction, it includes the following components:

[0021] Red mud (moisture content 45%-45%): 100 parts;

[0022] Sodium carboxymethyl cellulose (CMC-Na): 5 parts;

[0023] Snail shell powder (200 mesh): 10 parts;

[0024] Distiller's grains (protein content 15%-20%): 10 parts.

[0025] The selected red mud has a water content of 40%-45%, and the total mass of silicon dioxide (SiO2), iron(III) oxide (Fe2O3), and aluminum oxide (Al2O3) accounts for no less than 65%. The total mass of calcium oxide (CaO) and sodium oxide (Na2O) is no higher than 8%, and the titanium (Ti) content is between 2% and 8%. If the calcium oxide (CaO) in the selected red mud is greater than 8%, it needs to be soaked in 5% sulfate for more than 24 hours to precipitate calcium ions to meet the properties of red mud during preliminary modification.

[0026] Sodium carboxymethyl cellulose (CMC-Na), characterized in that the selected standard is medium-substituted sodium carboxymethyl cellulose (0.7≤DS≤0.9) or high-substituted sodium carboxymethyl cellulose (DS>0.9), its grade is food-grade sodium carboxymethyl cellulose, and its property is pure white.

[0027] The described snail shell powder (200 mesh), wherein the snail shell is one or a mixture of several of Cipangopaludina chinensis, Bellamya aeruginosa, Bullacta exarata or Ostrea rivularis shells.

[0028] The described distillers' grains are one of the distillers' grains after brewing white liquor with sorghum, corn, or rice as raw materials, and the protein content is 15%-20%.

[0029] The method for preparing the microbial carrier includes the following steps:

[0030] 1) Put the red mud with a water content of 40%-45% in parts by weight into a ball mill, add steel balls with a diameter of 3-5 mm according to the mass fraction ratio of 100:18, set the rotation speed at 500 r / min and the grinding time at 3 hours. After grinding, sieve it through a 200-mesh stainless steel sieve, and select the powder under the sieve for standby.

[0031] 2) Put the powder obtained in step 1 into a sodium hydroxide solution with a mass fraction of 10% for soaking. During the soaking process, use a stirrer to stir continuously. The stirring speed is greater than 100 revolutions per minute, and the soaking time is greater than 8 hours. After soaking, dry it naturally.

[0032] 3) Add the described amount of snail shell powder to a grinder for grinding. Set the rotation speed at 800 r / min and the grinding time at 30 minutes. After grinding, sieve it through a 200-mesh stainless steel sieve, and select the powder under the sieve for standby.

[0033] 4) Put the distillers' grains that meet the requirements of the present invention into a hot air drying device for drying until the water content is less than 10%. Then put the distillers' grains into a grinder, set the rotation speed at 800 r / min and the grinding time at 30 minutes. After grinding, sieve it through a 200-mesh stainless steel sieve, and select the powder under the sieve for standby.

[0034] 5) Sieve the sodium carboxymethyl cellulose (CMC-Na) that meets the requirements through a 200-mesh stainless steel sieve, and select the powder under the sieve for standby.

[0035] 6) Put the modified red mud powder, snail shell powder, distiller's grains powder, and sodium carboxymethyl cellulose powder obtained in steps 2, 3, 4, and 5 into a fully automatic traditional Chinese medicine pill-making machine, set the pill diameter to 6 mm, and set the speed to 500 pills per minute to make a microbial carrier for sewage treatment modified with red mud.

[0036] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and the technical features therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no conflict in the technical solutions, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A microbial carrier for sewage treatment based on red mud improvement, characterized in that: Prepared by the following method: (1) grinding red mud with a moisture content of 40% to 45% in a ball mill to preliminarily improve the physical structure of the red mud; then, soaking the preliminarily modified red mud in a sodium hydroxide solution, and then naturally drying it to obtain a red mud modified product; (2) The red mud modified product is mixed with sodium carboxymethyl cellulose CMC-Na, snail shell powder, and wine lees with a protein content of 15%-20% and then ground into 5-8 mm particles using a traditional Chinese medicine pill making machine. After naturally drying, the red mud modified microbial carrier for sewage treatment is obtained.

2. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: In step (2), according to the mass fraction: red mud: 100 parts; sodium carboxymethyl cellulose CMC-Na: 4-6 parts; snail shell powder: 9-11 parts; Lees: 9-11 parts.

3. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: The selected red mud has a moisture content of 40%-45%, the total mass of silicon dioxide, ferric oxide and aluminum oxide accounts for no less than 65% of the solid content, the total mass of calcium oxide and sodium oxide is no more than 8%, and the titanium content is between 2% and 8%.

4. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: If the calcium oxide content in the selected red mud is greater than 8%, it is necessary to soak it in 5% sulfate for more than 24 hours to precipitate the calcium ions to meet the red mud performance requirements during the initial modification.

5. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: The selection standard of sodium carboxymethyl cellulose CMC-Na is medium-substituted sodium carboxymethyl cellulose, 0.7≤DS≤0.9, or high-substituted sodium carboxymethyl cellulose, DS>0.9, and its grade is food-grade sodium carboxymethyl cellulose, and its property is pure white; the sodium carboxymethyl cellulose CMC-Na that meets the requirements is sieved with a 200-mesh stainless steel sieve, and the powder under the sieve is selected for use.

6. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: The snail shell powder is 200 mesh, and the snail shell is one or a mixture of Chinese round field snail, ring-edge snail, mud snail or oyster snail shell; the snail shell powder of the amount is added into a grinder for grinding, and the speed is set to 800r / min and the grinding time is 30 minutes. After the grinding is completed, it is sieved with a 200-mesh stainless steel sieve, and the powder under the sieve is selected for standby use.

7. A microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: The distiller's grains are selected from one of the distiller's grains after brewing liquor with sorghum, corn and rice as raw materials; the distiller's grains are placed in a hot air drying device for drying until the moisture content is less than 10%, and then the distiller's grains grinder is set to a speed of 800r / min and a grinding time of 30 minutes. After the grinding is completed, a 200-mesh stainless steel sieve is used for sieving, and the powder under the sieve is selected for use.

8. The microbial carrier for sewage treatment based on red mud improvement according to claim 1, characterized in that: The preparation method comprises the following specific steps: 1) putting the red mud with a moisture content of 40%-45% by weight into a ball mill, adding 3-5 mm diameter steel balls in a mass fraction ratio of 100:18 for grinding, setting a rotation speed of 500 r / min and a grinding time of 3 hours, sieving with a stainless steel 200 mesh sieve after grinding, and selecting the powder under the sieve for later use; 2) the powder obtained in step 1) is placed in a 10% by mass sodium hydroxide solution for soaking, and a stirrer is used for continuous stirring during the soaking process, the stirring speed is greater than 100 rpm, the soaking time is greater than 8 hours, and the powder is naturally dried after the soaking is completed; 3) Put the modified red mud powder, snail shell powder, distiller's grains powder and sodium carboxymethyl cellulose powder into a fully automatic Chinese medicine pill making machine, set the pill diameter to 6 mm, and set the speed to 500 pills per minute to make a red mud-modified microbial carrier for sewage treatment.