Preparation method of a biological suspension filler for treating wastewater and the filler

Abstract

The present invention discloses a preparation method and a filler of a biological suspended filler for wastewater treatment. The preparation method includes: by mass parts, extruding and molding 20-35 parts of activated carbon, 0.05-0.2 parts of composite metal salt, 70-80 parts of polyethylene, 0.5-0.2 parts of crosslinking agent and other auxiliary materials to obtain the biological suspended filler. By adding activated carbon, the present invention improves the wear resistance and surface roughness of the filler, thereby increasing the attachment sites of microorganisms and significantly enhancing the film-forming speed of microorganisms on the surface of the filler; in addition, voids are formed inside the suspended filler by the activated carbon, which plays a good slow-release role for the encapsulated composite metal salt; in the field of wastewater treatment, the biological suspended filler has broad application prospects and can be used as a biological attachment filler for aerobic tanks, anoxic tanks and anaerobic tanks, effectively increasing the biomass and microbial activity in the reaction tank; the biological suspended filler of the present invention has a long service life, and the composite metal salt is slowly released without causing pollution to the water body.

Description

Technical Field

[0001] The present invention belongs to the field of chemical drug analysis and detection, and specifically relates to a preparation method and packing of a biological suspension packing for treating wastewater. Background Art

[0002] Wastewater treatment includes physical treatment, chemical treatment and biological treatment. Among them, biological treatment is often used as the core process of wastewater treatment due to its low cost and high comprehensive treatment capacity. Biological treatment relies on the decomposition of microorganisms to degrade and remove pollutants in wastewater, so as to achieve the purpose of wastewater purification.

[0003] Biological treatment methods mainly include the activated sludge method and the biofilm method. The biofilm method is a method in which microorganisms form biological colonies on the surface of a carrier to participate in wastewater treatment. The packing is a key component in the biofilm method and is divided into fixed packing and fluidized suspension packing. The packing is not only the main carrier for the growth, reproduction and habitation of microorganisms, but also the place for biochemical reactions of pollutants in wastewater. Therefore, the properties of the packing directly affect the activity of microorganisms.

[0004] The prior art such as the invention patent CN1142895C discloses a biofilm carrier for water or wastewater purification and its application. This patent designs the internal and external structures of the packing to ensure the smooth flow of water, air and nutrients, and the packing is in a fluidized state in the reaction tank. However, the packing has poor microbial film-forming ability and cannot achieve a good slow-release effect. The metabolism of pollutants in wastewater is directly related to the activity of enzymes in microorganisms. Metal ions usually act as the active centers of enzymes and participate in the decomposition and metabolism of pollutants. Although wastewater usually contains elements such as carbon, nitrogen, phosphorus, hydrogen and oxygen required for the growth and metabolism of microorganisms, the lack of trace elements will inevitably affect the activity of microorganisms, thus affecting the effect of wastewater treatment.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a preparation method and packing of a biological suspension packing for treating wastewater, so as to achieve the purpose of improving the film-forming efficiency and activity of microorganisms in the biological suspension packing, and at the same time achieving a slow-release effect on the composite metal salt.

[0007] To solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0008] A preparation method of a suspension packing for treating wastewater, comprising:

[0009] By weight in parts, 20 to 35 parts of activated carbon, 0.05 to 0.2 parts of composite metal salt, 70 to 80 parts of polyethylene, 0.5 to 2 parts of crosslinking agent and other auxiliary materials are extruded and formed to obtain the biological suspension filler.

[0010] In the present invention, by adding 20 to 35 parts of activated carbon, the wear resistance and surface roughness of the biological suspension filler are improved. This not only increases the attachment sites of microorganisms, but also significantly improves the film-forming speed of microorganisms on the surface of the biological suspension filler. The activated carbon inside the biological suspension filler forms a void structure, which helps the sustained release effect of 0.05 to 0.2 parts of the composite metal salt embedded therein, thus ensuring the continuous stability of the microbial activity. Further, by adding 70 to 80 parts of polyethylene, 0.5 to 0.2 parts of crosslinking agent and other auxiliary materials and extruding and forming, the comprehensive performance of the suspension filler is optimized, so that it shows higher efficiency and stability in the wastewater treatment process.

[0011] Further, the other auxiliary materials are selected from one or more of antioxidant, calcium stearate, paraffin, foaming agent.

[0012] The antioxidant can improve the antioxidant performance of the filler, calcium stearate and paraffin can increase the hardness and stability of the filler, and the foaming agent can increase the porosity of the filler and improve the adsorption performance of the filler.

[0013] Further, first dry and weigh and mix the activated carbon and the composite metal salt, then add polyethylene, crosslinking agent and other auxiliary materials and mix them, and after mixing, extrude and form to obtain it.

[0014] By adding polyethylene, crosslinking agent and other auxiliary materials, the comprehensive performance of the suspension filler is optimized, so that it shows higher efficiency and stability in the wastewater treatment process.

[0015] Further, first place the activated carbon and the composite metal salt in an oven at 125 to 175 °C for drying; heat the mixer to 80 to 100 °C, take polyethylene, crosslinking agent and other auxiliary materials and mix them in the mixer, and after mixing, extrude and form at a temperature of 180 to 200 °C to obtain it.

[0016] Mixing the activated carbon, composite metal salt, polyethylene, crosslinking agent and other auxiliary materials and then extruding and forming is simple and convenient to operate and is suitable for industrial production.

[0017] Further, first place the activated carbon and the composite metal salt in an oven at 150 °C for drying for 8 h; heat the mixer to 80 °C, take polyethylene, crosslinking agent and other auxiliary materials and mix them in the mixer, and after mixing, extrude and form at a temperature of 180 °C to obtain it.

[0018] Further, the composite metal salt is selected from CoCl 2 , MnCl 2, ZnCl 2 , NiCl 2 , CuSO 4 , Na 2 , Na 4 , Na 2 , SeO 4 One or more of the above.

[0019] Furthermore, the composite metal salt includes CoCl 2 , MnCl 2 , ZnCl 2 , NiCl 2 , CuSO 4 , Na 2 , Na 4 , Na 2 , SeO 4 .

[0020] Furthermore, by mass, the composite metal salt includes 12 - 18 parts of CoCl 2 , 60 - 70 parts of MnCl 2 , 7 - 10 parts of ZnCl 2 , 1 - 2 parts of NiCl 2 , 2 - 3 parts of CuSO 4 , 1 - 2 parts of Na 2 , Na 4 , 1 - 2 parts of Na 2 , SeO 4 .

[0021] The metal ions in the composite metal salt can serve as nutrients for microorganisms, promoting the growth and metabolic activity of microorganisms and improving the efficiency of wastewater treatment. Some of these metal salts have a certain antibacterial effect, which can inhibit the growth of harmful microorganisms in the wastewater and maintain the stability of the microbial community. The metal ions in these metal salts also have different redox properties, which can promote the oxidation and decomposition of organic matter in the wastewater and improve the efficiency of wastewater treatment. By selecting a variety of metal salts in the present invention, multiple effects can be achieved, and the functions of different metal ions complement each other, improving the comprehensive performance of the filler and the wastewater treatment effect.

[0022] The present invention also provides a biological suspension filler for treating wastewater, which is prepared by using the preparation method described in any one of the above technical solutions.

[0023] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0024] By adding activated carbon, the present invention improves the wear resistance and surface roughness of the filler, thereby increasing the attachment sites of microorganisms and significantly enhancing the film-forming speed of microorganisms on the surface of the filler. In addition, activated carbon forms voids inside the suspended filler, playing a good slow-release role for the encapsulated composite metal salt. In the field of wastewater treatment, this biological suspended filler has broad application prospects and can be used as a biological attachment filler in aerobic tanks, anoxic tanks, and anaerobic tanks, effectively increasing the biomass and microbial activity in the reaction tank. The biological suspended filler of the present invention has a long service life, and the composite metal salt is slowly released without causing pollution to the water body.

[0025] The following is a more detailed description in conjunction with specific embodiments. Specific embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described clearly and completely below. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0027] Example 1

[0028] (1) Take 30 kg of activated carbon and 0.1 kg of composite metal salt (the composite metal salt is composed of 16.1 g of CoCl 2 , 68.5 g of MnCl 2 , 8.1 g of ZnCl 2 , 1.6 g of NiCl 2 , 2.4 g of CuSO 4 , 1.6 g of Na 2 MoO 4 , 1.7 g of Na 2 SeO 4 ), place it in an oven at 150 °C and dry for 8 h, and weigh until constant weight.

[0029] (2) Heat the mixer to 80 °C, take 80 kg of polyethylene, 1 kg of cross-linking agent, and 0.3 kg of antioxidant 1010, mix them, and then extrude and mold at a temperature of 180 °C. After molding, rinse with water and dry to obtain a Φ12×9 mm annular cross-shaped biological suspended filler.

[0030] Example 2

[0031] (1) Take 300 kg of activated carbon and 1.5 kg of composite metal salt (including 235 g of CoCl 2 , 1028 g of MnCl 2 , 127 g of ZnCl 2 , 18 g of NiCl 2 , 42 g of CuSO 4 , 21 g of Na 2MoO 4 、 29 g of Na 2 SeO 4 ), dehydrated by heating in an electric furnace and weighed until the weight no longer decreased significantly.

[0032] (2) Heat the mixer to 80 °C, take 900 kg of polyethylene, 15 kg of crosslinking agent, 3 kg of antioxidant 1010, 3 kg of antioxidant 168, 5 kg of calcium stearate, and 5 kg of blowing agent AC1, mix them, then heat to 180 °C for extrusion molding, and then soak, rinse, and dry with water to obtain honeycomb biological suspension fillers of Φ25×12 mm.

[0033] Example 3

[0034] (1) Take 20 kg of activated carbon and 0.05 kg of composite metal salt (the composite metal salt consists of 9 g of CoCl 2 、 35 g of MnCl 2 、 3.5 g of ZnCl 2 、 0.5 g of NiCl 2 、 1 g of CuSO 4 、 0.5 g of Na 2 MoO 4 、 0.5 g of Na 2 SeO 4 ), place it in an oven at 125 °C and dry for 8 h, and weigh until constant weight.

[0035] (2) Heat the mixer to 90 °C, take 70 kg of polyethylene, 0.5 kg of crosslinking agent, and 0.2 kg of antioxidant 1010, mix them, and then extrude and mold at a temperature of 190 °C. After molding, rinse with water and air-dry to obtain annular cross-shaped biological suspension fillers of Φ12×9 mm.

[0036] Example 4

[0037] (1) Take 20 kg of activated carbon and 0.05 kg of composite metal salt (the composite metal salt consists of 6 g of CoCl 2 、 34.5 g of MnCl 2 、 5 g of ZnCl 2 、 1 g of NiCl 2 、 1.5 g of CuSO 4 、 1 g of Na 2 MoO 4 、 1 g of Na 2 SeO 4 ), place it in an oven at 125 °C and dry for 8 h, and weigh until constant weight.

[0038] (2) Heat the mixer to 90 °C, take 70 kg of polyethylene, 0.5 kg of crosslinking agent, and 0.2 kg of antioxidant 1010, mix them, and then extrude and mold at a temperature of 190 °C. After molding, rinse with water and dry to obtain a Φ12×9 mm annular cross-shaped biological suspension filler.

[0039] Example 5

[0040] (1) Take 20 kg of activated carbon and 0.05 kg of composite metal salt (the composite metal salt consists of 6.5 g of CoCl 2 , 35 g of MnCl 2 , 3.5 g of ZnCl 2 , 1 g of NiCl 2 , 1.5 g of CuSO 4 , 1 g of Na 2 MoO 4 , 1 g of Na 2 SeO 4 ), place it in an oven at 175 °C and dry for 8 h, and weigh until the weight is constant.

[0041] (2) Heat the mixer to 100 °C, take 70 kg of polyethylene, 0.5 kg of crosslinking agent, and 0.2 kg of antioxidant 1010, mix them, and then extrude and mold at a temperature of 200 °C. After molding, rinse with water and dry to obtain a Φ12×9 mm annular cross-shaped biological suspension filler.

[0042] Experimental Example 1

[0043] This experimental example verified the influence of different composition components of the biological suspension filler on its performance.

[0044] The treatment scale of the experimental device is 1 L / h, and two reaction tanks are set up. The residence time of the first-stage reaction tank is 2 hours, and the residence time of the second-stage reaction tank is 8 hours. Aeration is carried out at the bottom of both reaction tanks, and the dissolved oxygen concentration is maintained at 4 mg / L. The reflux ratio of the mixed liquor is set at 300%, and the reflux ratio of the sludge is 100%. In the first-stage reaction tank and the second-stage reaction tank, the added volume of the suspended filler accounts for 30% of the tank volume. A certain coking wastewater anaerobic effluent is selected as the experimental water sample, and the suspended fillers of different experimental groups are added to the reaction tanks for comparative experiments.

[0045] Specifically, the anaerobic effluent of coking wastewater is introduced into the first-stage reaction tank at a rate of 1 L / h, and the residence time is controlled to be 2 hours. In the first-stage reaction tank, the selected suspended packing is added at a volume ratio of 30%, and bottom aeration is maintained to keep the dissolved oxygen concentration at 4 mg / L. The reflux ratio of the mixed liquor is adjusted to 300%, and the reflux ratio of the sludge is 100%. The mixed liquor of the first-stage reaction tank is introduced into the second-stage reaction tank, and the residence time is controlled to be 8 hours. In the second-stage reaction tank, the selected suspended packing is added again at a volume ratio of 30%. According to the experimental design, the suspended packing of different experimental groups is set, and other conditions are kept unchanged for comparative experiments. Samples are taken and analyzed regularly, and the treatment effect and water quality changes are recorded; the results are shown in Table 1 below:

[0046] Experimental group 1: The biological suspended packing prepared in Example 1 is selected.

[0047] Experimental group 2: The only difference between this experimental group and Example 1 is that no activated carbon is added.

[0048] Experimental group 3: The only difference between this experimental group and Example 1 is that no composite metal salt is added.

[0049] Table 1:

[0050]

[0051] First, the MLSS concentration of Experimental group 1 is the highest, at 5500 mg / L, which is 700 mg / L and 300 mg / L higher than that of Experimental group 2 and Experimental group 3 respectively. A higher MLSS concentration usually indicates a higher microbial biomass, which is beneficial to improving the efficiency and stability of wastewater treatment. Secondly, the COD removal rate of Experimental group 1 is 82.86%, which is 2.38% and 1.43% higher than that of Experimental group 2 and Experimental group 3 respectively. This shows that Experimental group 1 is more efficient in degrading organic matter in the wastewater. In addition, the N-NH3 removal rate of Experimental group 1 is 98.33%, far higher than 95.56% and 95% of Experimental group 2 and Experimental group 3 respectively. This indicates that Experimental group 1 performs better in removing ammonia nitrogen from the wastewater.

[0052] Taking into account the removal rates of COD and ammonia nitrogen and the MLSS concentration, Experimental group 1 is more superior in the comprehensive effect of wastewater treatment, with higher treatment efficiency and stability. Therefore, the biological suspended packing with activated carbon and composite metal salt in this application has achieved good results in the wastewater treatment experiment.

[0053] Experimental Example 2

[0054] This experimental example verified the removal effect of the biological suspended packing of the present invention on pollutants in wastewater compared with ordinary suspended packing. Specifically, similar to Experimental Example 1, anaerobic effluent from a certain coking wastewater was selected as the experimental water sample, and the suspended packing of different experimental groups was added to the reaction tank for a comparative experiment respectively. The results are shown in Table 2 below:

[0055] Experimental Group 1: Select the biological suspended packing prepared in Example 1.

[0056] Experimental Group 2: Ordinary suspended packing on the market (i.e., K3 type suspended packing, with a diameter of 25 mm, a thickness of 10 mm, made of high-density polyethylene, and a specific surface area > 500 m 2 / m 3 ).

[0057] Table 2:

[0058]

[0059] As can be seen from the above table, the MLSS concentration of Experimental Group 1 was 5500 mg / L, significantly higher than 4500 mg / L of Experimental Group 2. A higher MLSS concentration usually indicates a higher amount of microorganisms, which helps to improve the efficiency and stability of wastewater treatment. The COD removal rate of Experimental Group 1 was 82.86%, 5.72% higher than 77.14% of Experimental Group 2. This indicates that Experimental Group 1 was more efficient in degrading organic matter in the wastewater. Further, the N-NH3 removal rate of Experimental Group 1 was 98.33%, significantly higher than 93.89% of Experimental Group 2. This shows that Experimental Group 1 performed better in removing ammonia nitrogen from the wastewater.

[0060] Considering the removal rates of COD and ammonia nitrogen and the MLSS concentration comprehensively, Experimental Group 1 was more superior in the comprehensive effect of wastewater treatment, with higher treatment efficiency and stability. Therefore, the biological suspended packing of the present invention showed better effects in wastewater treatment.

[0061] Experimental Example 3

[0062] This experimental example verified the influence of the addition amount of composite metal salt on the performance of biological suspended packing. Specifically, similar to Experimental Example 1, anaerobic effluent from a certain coking wastewater was selected as the experimental water sample, and the suspended packing of different experimental groups was added to the reaction tank for a comparative experiment respectively. The results are shown in Table 3 below:

[0063] Experimental Group 1: Select the biological suspended packing prepared in Example 1.

[0064] Experimental Group 2: The difference from Example 1 was only that the addition amount of composite metal salt was 0.03 kg (wherein, the composite metal salt consisted of 4.83 g CoCl 2 , 20.55 g MnCl 2, 2.43 g of ZnCl 2 , 0.48 g of NiCl 2 , 0.72 g of CuSO 4 , 0.48 g of Na 2 MoO 4 , 0.51 g of Na 2 SeO 4 (composition), less than the range of 0.05 - 0.2 parts to be protected by the present invention.

[0065] Table 3:

[0066]

[0067] As can be seen from the above table, the COD removal rate of experimental group 1 reached 82.86%, significantly higher than 81.90% of experimental group 2. In addition, experimental group 1 was particularly superior in removing N-NH3, with a removal rate as high as 98.33%. In contrast, the N-NH3 removal rate of experimental group 2 was 96.67%. These data indicate that the formulation of experimental group 1 has significant advantages in improving the wastewater treatment effect, especially showing higher efficiency in removing COD and N-NH3, proving the superior performance of experimental group 1 in wastewater treatment.

[0068] Experimental Example 4

[0069] This experimental example verified the influence of the dosage ratio of CoCl 2 , MnCl 2 , ZnCl 2 in the composite metal salt on the performance of the biological suspension packing. Specifically, similar to experimental example 1, a certain coking wastewater anaerobic effluent was selected as the experimental water sample, and the suspension packings of different experimental groups were added to the reaction pool for comparative experiments respectively. The results are shown in Table 4 below:

[0070] Example 1: Select the biological suspension packing prepared in Example 1; CoCl 2 in Example 1: 16.1 g, MnCl 2 : 68.5 g, ZnCl 2 : 8.1 g;

[0071] Experimental group 1: The difference from Example 1 is only that: CoCl 2 : 13.8 g, MnCl 2 : 60 g, ZnCl 2 : 18.9 g;

[0072] Experimental group 2: The difference from Example 1 is only that: CoCl 2 : 11.1 g, MnCl 2 : 55.6 g, ZnCl 2: 26 g;

[0073] Experimental Group 3: The only difference from Example 1 is that CoCl 2 : 18.5 g, MnCl 2 : 68 g, ZnCl 2 : 6.2 g.

[0074] Table 4:

[0075]

[0076] Compared with Example 1, in Experimental Group 1, the dosage of ZnCl 2 in the composite metal salt is higher than the range of 7 - 10 parts, and the dosages of CoCl 2 and MnCl 2 are reduced. As can be seen from Table 4 above, the COD removal rate and N-NH3 removal rate of the biological suspended packing in Experimental Group 1 both decreased compared with Example 1.

[0077] Compared with Example 1, in Experimental Group 2, the dosage of ZnCl 2 in the composite metal salt is much higher than the range of 7 - 10 parts, the dosage of CoCl 2 is lower than the range of 12 - 18 parts, and the dosage of MnCl 2 is lower than the range of 60 - 70 parts. As can be seen from Table 4 above, the COD removal rate and N-NH3 removal rate of the biological suspended packing in Experimental Group 2 both decreased significantly compared with Example 1.

[0078] Compared with Example 1, in Experimental Group 3, the dosage of ZnCl 2 in the composite metal salt is lower than the range of 7 - 10 parts, and the dosage of CoCl 2 is slightly higher than the range of 12 - 18 parts. As can be seen from Table 4 above, the COD removal rate and N-NH3 removal rate of the biological suspended packing in Experimental Group 3 both decreased significantly compared with Example 1.

[0079] In summary, different ratios of the components of the composite metal salt will have a certain impact on the effect of the biological suspended packing in treating wastewater. When the dosage of ZnCl 2 is in the range of 7 - 10 parts, the dosage of CoCl 2 is in the range of 12 - 18 parts, and the dosage of MnCl 2 is in the range of 60 - 70 parts, the biological suspended packing has the highest removal rates of COD and N-NH3 and the best removal effect.

[0080] The above are only the preferred embodiments of the present invention, and there is no restriction on the present invention in any form. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent, without departing from the scope of the technical solution of the present invention, can make some changes or modifications using the technical content prompted above to form equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a biological suspension filler for treating wastewater, characterized in that: Calculated by weight, 20 to 35 parts of activated carbon and 0.05 to 0.2 parts of composite metal salt are first placed in an oven at 125 to 175° C. for drying; a mixer is heated to 80 to 100° C., and then 70 to 80 parts of polyethylene, 0.5 to 2 parts of a cross-linking agent, and other auxiliary materials are mixed in the mixer, and after mixing, the materials are extruded at a temperature of 180 to 200° C. to obtain a biological suspension filler; In terms of mass fractions, the composite metal salt includes 12 to 18 parts of CoCl2, 60 to 70 parts of MnCl2, 7 to 10 parts of ZnCl2, 1 to 2 parts of NiCl2, 2 to 3 parts of CuSO4, 1 to 2 parts of Na2MoO4, and 1 to 2 parts of Na2SeO4.

2. The method for preparing a biological suspension filler for treating wastewater according to claim 1, characterized in that: The other auxiliary materials are selected from one or more of antioxidants, calcium stearate, paraffin, and foaming agents.

3. The method for preparing a biological suspension filler for treating wastewater according to claim 1, characterized in that: First, place the activated carbon and the composite metal salt in an oven at 150°C and dry them for 8 hours; heat the mixer to 80°C, take polyethylene, a cross-linking agent and other auxiliary materials into the mixer for mixing, and extrude them at a temperature of 180°C to obtain the product.

4. A biological suspension filler for treating wastewater, characterized in that: The product is prepared by the preparation method described in any one of claims 1 to 3.

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