CN114853206A - Method for promoting coagulation precipitation of anaerobic fermentation biogas slurry of livestock and poultry manure - Google Patents
Method for promoting coagulation precipitation of anaerobic fermentation biogas slurry of livestock and poultry manure Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
- C02F1/56—Macromolecular compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/125—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using screw filters
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F2001/007—Processes including a sedimentation step
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/20—Nature of the water, waste water, sewage or sludge to be treated from animal husbandry
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Abstract
A method for promoting the coagulation and precipitation of anaerobic fermentation biogas slurry of livestock and poultry feces comprises the steps of removing impurities to obtain primary biogas slurry; the primary biogas slurry enters a primary flocculation tank, calcium chloride, sodium sulfate and cationic polyacrylamide are added into the primary flocculation tank, and the primary biogas slurry is stirred; after stirring, the biogas slurry enters a primary sedimentation tank for sedimentation to obtain primary supernatant biogas slurry, and then enters a secondary flocculation tank for further removing suspended matters; the primary supernatant biogas slurry enters a secondary flocculation tank, a flocculating agent is added, and stirring is carried out; and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank for sedimentation to obtain secondary supernatant biogas slurry. In the process of generating the calcium sulfate crystals, the regular calcium sulfate crystals can better provide a core for flocs, and large floc coagulation is further formed by mutual flocculation and sweeping flocculation with suspended matters and serves as a weighting agent, so that the settling rate and the solid-liquid separation rate of the suspended matters are remarkably improved, and the problems of low settling rate and slow solid-liquid separation of the suspended matters in the livestock and poultry manure anaerobic fermentation biogas slurry processed by the traditional flocculating agent and the coagulant aid are solved.
Description
Technical Field
The invention belongs to the technical field of environmental protection, and particularly relates to a method for promoting coagulation and precipitation of livestock and poultry manure biogas slurry by a double-salt coprecipitation method.
Background
Along with the rapid development of the domestic large-scale livestock and poultry breeding industry, the biogas engineering construction matched with the livestock and poultry breeding industry also shows an obvious growth trend. Anaerobic fermentation has become an important treatment technology of livestock and poultry breeding feces, but biogas slurry generated by anaerobic fermentation is high-concentration organic wastewater and is in a semi-fluid slurry state without solid-liquid separation, the upper layer biogas slurry after solid-liquid separation is dark suspension, and the content of suspended matters is as high as 5000-40000 mg/L. The components of the biogas slurry are very complex, and the biogas slurry contains a large amount of undigested raw material scraps, polysaccharide substances, polypeptide molecules, protein molecules, microbial cells and the like, and a stable mixed system with colloid and emulsion characteristics is formed along with the formation of liquid, so that suspended substances of the biogas slurry are difficult to naturally settle, and the solid-liquid separation performance is very poor. The high-concentration suspended matters seriously affect the normal operation of subsequent biogas slurry treatment. The key technical problem of treating and disposing the livestock and poultry manure biogas slurry is to select proper treatment conditions and improve the settling property of the biogas slurry.
The flocculating settling method can effectively remove suspended matters in the organic wastewater, common flocculating agents comprise polyaluminium chloride, aluminum sulfate, ferric chloride and the like, and the flocculating agents have the advantages of high hydrolysis speed, large flocculation specific gravity, rapid sedimentation, low price and the like when used for treating the conventional wastewater. However, for the stable mixed system of the livestock and poultry manure and biogas slurry with the characteristics of colloid and emulsion, the problems of low floc strength, poor compactness, loose structure and the like exist in the traditional flocculant treatment, so that the suspended matter sedimentation rate is low and the solid-liquid separation efficiency is low. Calcium ions can change the surface electrical property and aggregation state of the colloid and the emulsion through the electrical property neutralization and the adsorption and bridging action, and the sedimentation rate of suspended matters is accelerated. However, for the biogas slurry containing more crude protein, such as chicken manure, the traditional flocculant and calcium ion treatment effect is not obvious, and the concentration of suspended matters in the effluent water is at a high level, so that the subsequent biogas slurry treatment requirement is still difficult to meet.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for promoting the coagulation and precipitation of anaerobic fermentation biogas slurry of livestock and poultry manure through double-salt precipitation.
In order to solve the technical problems, the invention adopts the following technical scheme: a method for promoting the coagulation and precipitation of anaerobic fermentation biogas slurry of livestock and poultry feces is characterized by comprising the following steps: (1) biogas slurry pretreatment: removing coarse impurities and large granular suspended matters from the anaerobic fermentation biogas slurry of the livestock and poultry manure through a spiral extrusion type solid-liquid separator to obtain primary biogas slurry; (2) primary coagulation treatment: the primary biogas slurry enters a primary flocculation tank, calcium chloride and sodium sulfate which serve as coagulant aids are respectively added into the primary biogas slurry, cationic polyacrylamide which serves as a flocculating agent is stirred to enable the calcium chloride and the sodium sulfate to react to generate calcium sulfate, so that a biogas slurry colloid and an emulsion liquid system are unstable, and meanwhile, regular calcium sulfate crystals are generated to better provide cores for flocs and serve as weighting agents to generate flocculation and precipitation under the action of the flocculating agents; (3) primary precipitation: after stirring, the biogas slurry enters a primary sedimentation tank for sedimentation to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank, and is stirred after a flocculating agent is added; (5) secondary precipitation: after stirring, the biogas slurry enters a secondary sedimentation tank for sedimentation, and secondary supernatant biogas slurry is obtained.
The scheme is characterized in that in the step (1), the biogas slurry is a fermentation liquid which is represented by biogas slurry produced after anaerobic fermentation of livestock and poultry manure and has the characteristics of colloid and emulsion, and the concentration of suspended matters is more than 5000 mg/L.
In the step (2), the adding proportion of the calcium chloride and the sodium sulfate is calculated by the relative molecular mass of the anhydrous calcium chloride and the anhydrous sodium sulfate, the total adding amount is 1.00 g/L-13.00 g/L, and the adding amount of the flocculating agent is as follows: flocculant = 10: 1 weight ratio, the molecular weight of the added cationic polyacrylamide is 800-1000 ten thousand.
In the step (4), the flocculating agent is one of polyaluminium chloride, polyaluminium ferric chloride, ferric chloride and polyacrylamide.
The stirring in the step (2) refers to rapid stirring for 2 min at the rotating speed of 200-400 r/min, and low-speed stirring for 20 min at the rotating speed of 50-150 r/min after the rapid stirring is finished.
The settling time of the first-stage settling pond is 4-8 h.
The stirring in the step (4) refers to rapid stirring for 2 min at the rotating speed of 200-400 r/min, and low-speed stirring for 20 min at the rotating speed of 50-150 r/min after the rapid stirring is finished.
The sedimentation time of the secondary sedimentation tank is 4-8 h.
The invention has the following beneficial effects: due to the existence of a colloid and emulsion characteristic stable mixed system in the anaerobic fermentation biogas slurry of livestock and poultry feces, the traditional coagulation treatment is difficult to realize the rapid sedimentation of suspended matters and the high-efficiency separation of solid and liquid, and the subsequent biogas slurry treatment and disposal requirements are difficult to meet. According to the invention, calcium chloride and sodium sulfate are used as coagulant aids, cationic polyacrylamide is used as a flocculant, except for the electrical neutralization effect of the traditional flocculant in the flocculation process, the electrical neutralization and adsorption bridging effect of calcium ions in the flocculation process, in the process of generating calcium sulfate precipitate, the generated calcium sulfate crystal provides a core for floc formation, large floc coagulation is further formed through mutual flocculation and rolling sweep flocculation with suspended matters, and meanwhile, the generated calcium sulfate can also be used as a weighting agent to promote solid-liquid separation of biogas slurry, so that the problems of low settling rate and low solid-liquid separation efficiency of the traditional coagulant aids and flocculants in treating the suspended matters are solved. Compared with other double-salt coprecipitations, the generated calcium sulfate crystal has a more regular crystal structure, so that the calcium sulfate crystal has better mutual flocculation and sweeping flocculation effects. The treatment method is simple and easy to implement, and the whole process is low in operation and maintenance cost, so that the method has high social environmental benefit, economic benefit and wide market application prospect.
Drawings
FIG. 1 is a flow chart of a double-salt precipitation method for promoting coagulation precipitation of anaerobic fermentation biogas slurry of livestock and poultry manure.
In the figure: 1-biogas slurry; 2-a spiral extrusion type solid-liquid separator; 3-a first-stage flocculation tank; 4-a first-stage sedimentation tank; 5-a secondary flocculation tank; 6-a secondary sedimentation tank; 7-a dosing pump; 8-bottom mud; 9-separated solid biogas residue.
Detailed Description
Comparative example 1: a method for promoting biogas slurry coagulation and precipitation by using a traditional flocculating agent comprises the following steps: (1) biogas slurry pretreatment: pretreating chicken manure fermentation liquor by a spiral extrusion type solid-liquid separator 2 (Zhengzhou Juteng, type 180) to obtain primary biogas slurry, wherein the concentration of suspended matters is 15940 mg/L; (2) primary coagulation treatment: taking 1000 ml of primary biogas slurry to a primary flocculation tank 3, adding 0.10 g/L cationic polyacrylamide (molecular weight 800 ten thousand) through a dosing pump 7, rapidly stirring for 2 min at the rotating speed of 300 r/min, and after the rapid stirring is finished, stirring for 20 min at a low speed of 100 r/min; (3) primary precipitation: after stirring, allowing the biogas slurry to enter a primary sedimentation tank 4 for standing and sedimentation for 6 hours to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank 5, 3.00 g/L ferric chloride is added through a dosing pump 7, the mixture is rapidly stirred for 2 min at the rotating speed of 300 r/min, and the mixture is rapidly stirred for 20 min at the low speed of 100 r/min after the rapid stirring is finished; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank 6 for standing and sedimentation for 6 hours to obtain secondary supernatant biogas slurry.
Comparative example 2: the same parts of the comparative example and the comparative example 1 are not described again, except that: the addition amount of the cationic polyacrylamide is 0.50 g/L.
Comparative example 3: the same parts of the comparative example and the comparative example 1 are not described again, except that: the addition amount of the cationic polyacrylamide is 0.90 g/L.
Comparative example 4: the same parts of the comparative example and the comparative example 1 are not described again, except that: the flocculant is added with calcium chloride, the addition amount of the calcium chloride is 1.00 g/L, and the addition amount of the coagulant aid cationic polyacrylamide is 0.10 g/L.
Comparative example 5: the same parts of the comparative example and the comparative example 1 are not described again, except that: the flocculant is added with 5.00 g/L of calcium chloride and 0.50 g/L of coagulant aid cationic polyacrylamide.
Comparative example 6: the same parts of the comparative example and the comparative example 1 are not described again, except that: the flocculant is added with 9.00 g/L of calcium chloride and 0.90 g/L of coagulant aid cationic polyacrylamide.
The effect of the above embodiment is:
when the traditional flocculating agent cationic polyacrylamide (comparative examples 1-3) and calcium chloride are combined with the cationic polyacrylamide (comparative examples 4-6) to treat the chicken manure biogas slurry, under the action of flocculating agents with different addition amounts, the electric property and aggregation state of the surfaces of colloid and emulsion are changed through the electric property neutralization and the adsorption bridging action, suspended matters are removed to a certain extent, but under the optimal removal condition (comparative example 6), the concentration of suspended matters in secondary precipitated water is still higher than 1480 mg/L, which is far higher than the standard of 200 mg/L specified in the discharge standard of pollutants for livestock and poultry industry (GB 18596-2001), and the subsequent treatment of biogas slurry is not facilitated.
Example 1: a method for promoting biogas slurry coagulation and precipitation by combining calcium sulfate with cationic polyacrylamide comprises the following steps: (1) biogas slurry pretreatment: pretreating chicken manure fermentation liquor by a spiral extrusion type solid-liquid separator 2 (Zhengzhou Juteng, type 180) to obtain primary biogas slurry, wherein the concentration of suspended matters is 15940 mg/L; (2) primary coagulation treatment: taking 1000 ml of primary biogas slurry to a primary flocculation tank 3, sequentially adding 1.00 g/L calcium sulfate and 0.10 g/L cationic polyacrylamide (molecular weight is 800 ten thousand) by a dosing pump 7, rapidly stirring for 2 min at a rotating speed of 300 r/min, and after the rapid stirring is finished, stirring for 20 min at a low speed of 100 r/min; (3) primary precipitation: after stirring, allowing the biogas slurry to enter a primary sedimentation tank 4 for standing and sedimentation for 6 hours to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank 5, 3.00 g/L ferric chloride is added through a dosing pump 7, the mixture is rapidly stirred for 2 min at the rotating speed of 300 r/min, and the mixture is rapidly stirred for 20 min at the low speed of 100 r/min after the rapid stirring is finished; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank 6 for standing and sedimentation for 6 hours to obtain secondary supernatant biogas slurry.
Example 2: the same parts of this embodiment as embodiment 1 will not be described again, but the differences are: the addition amount of calcium sulfate is 3.00 g/L, and the addition amount of cationic polyacrylamide is 0.30 g/L.
Example 3: the same parts of this embodiment as embodiment 1 will not be described again, but the differences are: the addition amount of calcium sulfate is 5.00 g/L, and the addition amount of cationic polyacrylamide is 0.50 g/L.
Example 4: the same parts of this embodiment as embodiment 1 will not be described again, but the differences are: the addition amount of calcium sulfate is 7.00 g/L, and the addition amount of cationic polyacrylamide is 0.70 g/L.
Example 5: the same parts of this embodiment as embodiment 1 will not be described again, but the differences are: the addition amount of calcium sulfate is 9.00 g/L, and the addition amount of cationic polyacrylamide is 0.90 g/L.
The effect of the above embodiment is:
when the calcium sulfate is directly added to treat the chicken manure biogas slurry (examples 1-5), the calcium sulfate is difficult to dissolve in water, and calcium ions dissolved in the biogas slurry are less, so the effects of electrical neutralization and adsorption bridging are not obvious, but the suspended matter removal rate is improved by a small effect compared with the case of adding calcium chloride as a flocculating agent (comparative examples 4-6), but the suspended matter concentration is still reduced to below 5730 mg/L through one-time precipitation. Thus, the main mechanism of the addition of the calcium sulphate reagent is: the calcium sulfate crystals provide a core for floc formation, large floc coagulation is further formed through mutual flocculation and sweeping flocculation with suspended matters, and meanwhile, the calcium sulfate crystals are used as a weighting agent to promote solid-liquid separation of the biogas slurry, so that the suspended matters are removed. The suspended matters in the effluent obtained through the secondary coagulation sedimentation are greatly removed, but the concentration of the suspended matters is still over 1000 mg/L, the concentration is far higher than the standard of 200 mg/L specified in the discharge Standard of pollutants for livestock and poultry Breeding (GB 18596-2001), and the subsequent treatment and disposal of the biogas slurry are not facilitated.
Example 6: a method for promoting biogas slurry coagulation and precipitation by generating calcium alginate combined with cationic polyacrylamide from calcium chloride and sodium alginate comprises the following steps: (1) biogas slurry pretreatment: pretreating chicken manure fermentation liquor by a spiral extrusion type solid-liquid separator 2 (Zhengzhou Juteng, type 180) to obtain primary biogas slurry, wherein the concentration of suspended matters is 15940 mg/L; (2) primary coagulation treatment: taking 1000 ml of primary biogas slurry to a primary flocculation tank 3, sequentially adding 1.00 g/L calcium chloride, 2.00 g/L sodium alginate and 0.10 g/L cationic polyacryl (molecular weight is 800 ten thousand) through a dosing pump 7, rapidly stirring for 2 min at the rotating speed of 300 r/min, and after the rapid stirring is finished, stirring for 20 min at low speed of 100 r/min; (3) primary precipitation: after stirring, allowing the biogas slurry to enter a primary sedimentation tank 4 for standing and sedimentation for 6 hours to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank 5, 3.00 g/L ferric chloride is added through a dosing pump 7, the mixture is rapidly stirred for 2 min at the rotating speed of 300 r/min, and the mixture is rapidly stirred for 20 min at the low speed of 100 r/min after the rapid stirring is finished; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank 6 for standing and sedimentation for 6 hours to obtain secondary supernatant biogas slurry.
Example 7: the same parts of this embodiment as those of embodiment 6 will not be described again, except that: the addition amount of calcium chloride is 2.00 g/L, the addition amount of sodium alginate is 4.00 g/L, and the addition amount of cationic polyacrylic acid is 0.20 g/L.
Example 8: the same parts of this embodiment as those of embodiment 6 will not be described again, except that: the addition amount of calcium chloride is 3.00 g/L, the addition amount of sodium alginate is 6.00 g/L, and the addition amount of cationic polyacrylic acid is 0.30 g/L. Example 9: the same parts of this embodiment as those of embodiment 6 will not be described again, except that: the addition amount of calcium chloride is 4.00 g/L, the addition amount of sodium alginate is 8.00 g/L, and the addition amount of cationic polyacrylic acid is 0.40 g/L.
Example 10: the same parts of this embodiment as those of embodiment 6 will not be described again, except that: the addition amount of calcium chloride is 5.00 g/L, the addition amount of sodium alginate is 10.00 g/L, and the addition amount of cationic polyacrylic acid is 0.50 g/L.
The effect of the above embodiment is:
when the chicken manure biogas slurry is treated by combining calcium chloride and sodium alginate (examples 6-10), compared with the calcium chloride treatment biogas slurry (comparative examples 4-6), the removal effect of the primary precipitate suspended matters is improved to a certain extent, and the concentration of the suspended matters is below 4370 mg/L. Calcium ions replace sodium ions to generate calcium alginate gel, which has a good removing effect on protein substances and suspended matters in the biogas slurry, and in addition, the calcium ions have an electric neutralization and adsorption bridging effect to further remove the suspended matters, however, as the addition amount of the flocculating agent is increased (examples 8-10), more gel is generated to increase the viscosity of the biogas slurry, and the concentration of the suspended matters is increased. Under the optimal addition amount of the flocculating agent, the concentration of the effluent of the primary supernatant after secondary coagulation is over 1830 mg/L, which is far higher than the 200 mg/L standard specified in the livestock and poultry Breeding pollutant discharge standard (GB 18596-2001), and is not beneficial to the subsequent biogas slurry treatment and disposal.
Example 11: a method for promoting biogas slurry coagulation and precipitation by combining calcium chloride with sodium carbonate to generate calcium carbonate and combining cationic polyacrylamide comprises the following steps: (1) biogas slurry pretreatment: pretreating chicken manure fermentation liquor by a spiral extrusion type solid-liquid separator 2 (Zhengzhou Juteng, type 180) to obtain primary biogas slurry, wherein the concentration of suspended matters is 15940 mg/L; (2) primary coagulation treatment: taking 1000 ml of primary biogas slurry to a primary flocculation tank 3, sequentially adding 0.49 g/L calcium chloride, 0.51g/L sodium carbonate and 0.10 g/L cationic polyacrylamide (molecular weight is 800 ten thousand) through a dosing pump 7, rapidly stirring for 2 min at the rotating speed of 300 r/min, and after the rapid stirring is finished, stirring for 20 min at low speed of 100 r/min; (3) primary precipitation: after stirring, allowing the biogas slurry to enter a primary sedimentation tank 4 for standing and sedimentation for 6 hours to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank 5, 3.00 g/L ferric chloride is added through a dosing pump 7, the mixture is rapidly stirred for 2 min at the rotating speed of 300 r/min, and the mixture is rapidly stirred for 20 min at the low speed of 100 r/min after the rapid stirring is finished; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank 6 for standing and sedimentation for 6 hours to obtain secondary supernatant biogas slurry.
Example 12: the same parts of this embodiment as those of embodiment 11 will not be described again, except that: the addition amount of calcium chloride is 1.47 g/L, the addition amount of sodium carbonate is 1.53 g/L, and the addition amount of cationic polyacrylic acid is 0.30 g/L.
Example 13: the same parts of this embodiment as those of embodiment 11 will not be described again, except that: the addition amount of calcium chloride is 2.45 g/L, the addition amount of sodium carbonate is 2.55 g/L, and the addition amount of cationic polyacrylic acid is 0.50 g/L.
Example 14: the same parts of this embodiment as those of embodiment 11 will not be described again, except that: the addition amount of calcium chloride is 3.43 g/L, the addition amount of sodium carbonate is 3.57 g/L, and the addition amount of cationic polyacrylic acid is 0.70 g/L.
Example 15: the same parts of this embodiment as those of embodiment 11 will not be described again, except that: the addition amount of calcium chloride is 4.41 g/L, the addition amount of sodium carbonate is 4.59 g/L, and the addition amount of cationic polyacrylic acid is 0.90 g/L.
The effect of the above embodiment is:
when the calcium chloride is combined with the sodium carbonate to treat the chicken manure biogas slurry (examples 11-15), the removal effect of the primary precipitate suspended matters is improved to a certain extent compared with that of calcium chloride treated biogas slurry (comparative examples 4-6), and the concentration of the suspended matters is less than 5340 mg/L. Therefore, the calcium chloride and sodium carbonate combined biogas slurry is not only due to the electric neutralization and adsorption bridging effects of calcium ions, but also due to the mutual flocculation and rolling and sweeping flocculation effects in the process of generating calcium carbonate, so that the removal rate of suspended matters is improved. The primary coagulation suspension concentration is still at a high level. Under the condition of the optimal addition amount of the flocculating agent, the concentration of effluent water of the primary supernatant biogas slurry after secondary coagulation is more than 1240 mg/L, and the concentration is far higher than the standard of 200 mg/L specified in livestock and poultry breeding industry pollutant discharge standard (GB 18596-2001), and is not beneficial to subsequent biogas slurry treatment and disposal.
Example 16: a method for promoting biogas slurry coagulating sedimentation by combining calcium sulfate generated by calcium chloride and sodium sulfate and cationic polyacrylamide comprises the following steps: (1) biogas slurry pretreatment: pretreating chicken manure fermentation liquor by a spiral extrusion type solid-liquid separator 2 (Zhengzhou Juteng, type 180) to obtain primary biogas slurry, wherein the concentration of suspended matters is 15940 mg/L; (2) primary coagulation treatment: taking 1000 ml of primary biogas slurry to a primary flocculation tank 3, sequentially adding 0.22 g/L calcium chloride, 0.28 g/L sodium sulfate and 0.05 g/L cationic polyacryl (molecular weight is 800 ten thousand) through a dosing pump 7, rapidly stirring for 2 min at the rotating speed of 300 r/min, and after the rapid stirring is finished, stirring for 20 min at low speed of 100 r/min; (3) primary precipitation: after stirring, allowing the biogas slurry to enter a primary sedimentation tank 4 for standing and sedimentation for 6 hours to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank 5, 3.00 g/L ferric chloride is added through a dosing pump 7, the mixture is rapidly stirred for 2 min at the rotating speed of 300 r/min, and the mixture is rapidly stirred for 20 min at the low speed of 100 r/min after the rapid stirring is finished; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank 6 for standing and sedimentation for 6 hours to obtain secondary supernatant biogas slurry.
Example 17: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 0.44 g/L, the addition amount of sodium sulfate is 0.56 g/L, and the addition amount of cationic polyacrylic acid is 0.10 g/L.
Example 18: the same parts of this embodiment as those of embodiment 16 will not be described again, and the differences are: the addition amount of calcium chloride is 1.32 g/L, the addition amount of sodium sulfate is 1.68 g/L, and the addition amount of cationic polyacrylic acid is 0.30 g/L.
Example 19: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 2.20 g/L, the addition amount of sodium sulfate is 2.80 g/L, and the addition amount of cationic polyacrylic acid is 0.50 g/L.
Example 20: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 3.08 g/L, the addition amount of sodium sulfate is 3.92 g/L, and the addition amount of cationic polyacrylic acid is 0.70 g/L.
Example 21: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 3.96 g/L, the addition amount of sodium sulfate is 5.04 g/L, and the addition amount of cationic polyacrylic acid is 0.90 g/L.
Example 22: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 4.84 g/L, the addition amount of sodium sulfate is 6.16 g/L, and the addition amount of cationic polyacrylic acid is 0.11 g/L.
Example 23: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 5.72 g/L, the addition amount of sodium sulfate is 7.28 g/L, and the addition amount of cationic polyacrylic acid is 0.13 g/L.
Example 24: the same parts of this embodiment as those of embodiment 16 will not be described again, except that: the addition amount of calcium chloride is 6.60 g/L, the addition amount of sodium sulfate is 8.40 g/L, and the addition amount of cationic polyacrylic acid is 0.15 g/L.
The effect of the above embodiment is:
when the chicken manure biogas slurry is treated by combining calcium chloride and sodium sulfate (examples 16-24), compared with the direct addition of calcium sulfate (examples 1-5), the removal effect of primary coagulated suspended matters is greatly improved, and the concentration of the primary coagulated suspended matters is reduced from 2910 mg/L to 1440mg/L under the optimal addition amount (examples 5 and 21), which indicates that the coagulated precipitate not only has the electric neutralization and adsorption-bridge action of calcium ions, but also has the mutual flocculation and rolling sweeping flocculation action in the process of generating calcium sulfate, thereby improving the removal rate of suspended matters, greatly improving the removal rate of the primary supernatant biogas slurry in secondary coagulation, and reaching the effluent concentration of 30 mg/L through secondary coagulation to reach the standard of 200 mg/L specified in the discharge Standard of pollutants for livestock and poultry Breeding (GB 18596-2001). Compared with the biogas slurry treated by combining calcium chloride and sodium alginate (examples 6-10), the removal effect of the primary coagulation suspended matters is improved to a certain extent, and under the optimal addition amount (examples 7 and 21), the concentration of the primary coagulation suspended matters is reduced from 2620 mg/L to 1440mg/L, which is mainly that calcium ions replace sodium ions to generate calcium alginate gel, so that the calcium alginate gel has a good removal effect on protein substances and suspended matters in the biogas slurry, however, along with the increase of the addition amount of a flocculating agent (examples 8-10), more gel is generated to increase the viscosity of the biogas slurry, and the concentration of the suspended matters is increased on the contrary. Compared with the biogas slurry treated by combining calcium chloride and sodium carbonate (examples 11-15), although the two mechanisms of action are realized by coprecipitation, the calcium chloride and the sodium sulfate have larger improvement on the removal effect of primary coagulation and secondary coagulation suspended matters, under the optimal addition amount (examples 13 and 21), the concentration of the primary coagulation suspended matters is reduced from 4420 mg/L to 1440mg/L, and the concentration of the secondary coagulation effluent suspended matters is 30 mg/L, which reaches the standard of 200 mg/L (examples 17-23) specified in the livestock breeding pollutant discharge standard (GB 18596-2001), thereby being beneficial to the subsequent treatment of the biogas slurry treated by the subsequent treatment. The crystal structure of the generated calcium sulfate sediment is more regular than that of the calcium carbonate sediment, so that the crystal structure provides better opportunity and effect for forming a core for flocs, and the mutual flocculation and the scroll sweeping flocculation effect are enhanced. However, too little addition results in insufficient reaction and inefficient removal of suspended matter (example 16); the excessive addition amount can change the charges in the biogas slurry from negative to positive, thereby causing mutual repulsion of suspended matters with the same positive charges and reducing the removal efficiency of the suspended matters (example 24).
Claims (8)
1. A method for promoting the coagulation and precipitation of anaerobic fermentation biogas slurry of livestock and poultry feces is characterized by comprising the following steps: (1) biogas slurry pretreatment: removing coarse impurities and large granular suspended matters from the anaerobic fermentation biogas slurry of the livestock and poultry manure through a spiral extrusion type solid-liquid separator to obtain primary biogas slurry; (2) primary coagulation treatment: the primary biogas slurry enters a primary flocculation tank, calcium chloride and sodium sulfate are respectively added into the biogas slurry as coagulant aids, cationic polyacrylamide is used as a flocculant, and the mixture is stirred to react the calcium chloride and the sodium sulfate to generate calcium sulfate; (3) primary precipitation: after stirring, the biogas slurry enters a primary sedimentation tank for sedimentation to obtain primary supernatant biogas slurry; (4) secondary coagulation treatment: the primary supernatant biogas slurry enters a secondary flocculation tank, and is stirred after a flocculating agent is added; (5) secondary precipitation: and after stirring, allowing the biogas slurry to enter a secondary sedimentation tank for sedimentation to obtain secondary supernatant biogas slurry.
2. The method for promoting the coagulating sedimentation of the anaerobic fermentation biogas slurry of livestock and poultry manure according to claim 1, wherein in the step (1), the biogas slurry is a fermentation liquid which is represented by biogas slurry produced after the anaerobic fermentation of livestock and poultry manure and has the characteristics of colloid and emulsion, and the concentration of suspended matters is more than 5000 mg/L.
3. The method for promoting the coagulation sedimentation of the anaerobic fermentation biogas slurry of the livestock and poultry manure according to claim 1, wherein in the step (2), the adding proportion of calcium chloride and sodium sulfate is 1.00 g/L-13.00 g/L in terms of relative molecular mass of anhydrous calcium chloride and anhydrous sodium sulfate, and the adding amount of a flocculating agent is as follows: flocculant = 10: 1, and the molecular weight of the cationic polyacrylamide is 800-1000 ten thousand.
4. The method for promoting the coagulation and precipitation of the anaerobic fermentation biogas slurry of the livestock and poultry manure according to claim 1, wherein the flocculant added in the step (4) is one of polyaluminium chloride, polyaluminium ferric chloride, ferric chloride and polyacrylamide.
5. The method for promoting the coagulation sedimentation of the anaerobic fermentation biogas slurry of livestock and poultry feces according to claim 1, wherein the stirring in the step (2) is rapid stirring at a rotation speed of 200-400 r/min for 2 min, and low-speed stirring at a speed of 50-150 r/min for 20 min after the rapid stirring is completed.
6. The method for promoting the coagulation and precipitation of the anaerobic fermentation biogas slurry of livestock and poultry manure according to claim 1, wherein the precipitation time of the first-stage sedimentation tank is 4-8 h.
7. The method for promoting the coagulation sedimentation of the anaerobic fermentation biogas slurry of livestock and poultry feces according to claim 1, wherein the stirring in the step (4) is performed at a rotation speed of 200-400 r/min for 2 min, and after the completion of the rapid stirring, the stirring is performed at a low speed of 50-150 r/min for 20 min.
8. The method for promoting the coagulation and precipitation of the anaerobic fermentation biogas slurry of livestock and poultry manure according to claim 1, wherein the precipitation time of the secondary sedimentation tank is 4-8 h.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5897810A (en) * | 1996-02-16 | 1999-04-27 | Yutaka Tamaura | Coagulating agent for wastewater |
| CN102107937A (en) * | 2011-01-07 | 2011-06-29 | 鞍钢附企给排水净水剂厂 | Coal washing water treatment agent |
| CN104478175A (en) * | 2014-12-24 | 2015-04-01 | 北京桑德环境工程有限公司 | Treatment system and method for biogas slurry produced from anaerobic fermentation of kitchen waste |
| CN104909502A (en) * | 2015-06-24 | 2015-09-16 | 南京元凯生物能源环保工程有限公司 | Biogas slurry pretreatment method |
| CN105129946A (en) * | 2015-09-14 | 2015-12-09 | 镇江华立煤质制样设备有限公司 | Efficient coal-washing wastewater treatment agent |
| CN111233167A (en) * | 2020-01-21 | 2020-06-05 | 中国科学院成都生物研究所 | Alcaligenes faecalis and application thereof in chicken manure biogas slurry flocculation |
| CN112794555A (en) * | 2020-12-23 | 2021-05-14 | 联合环境技术(天津)有限公司 | Novel method for treating wastewater by reinforced coagulation |
| CN216129468U (en) * | 2021-08-11 | 2022-03-25 | 北京航天威科环保科技有限公司 | A concentrated system that is used for animal manure anaerobic fermentation natural pond liquid |
-
2022
- 2022-04-11 CN CN202210376144.1A patent/CN114853206B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5897810A (en) * | 1996-02-16 | 1999-04-27 | Yutaka Tamaura | Coagulating agent for wastewater |
| CN102107937A (en) * | 2011-01-07 | 2011-06-29 | 鞍钢附企给排水净水剂厂 | Coal washing water treatment agent |
| CN104478175A (en) * | 2014-12-24 | 2015-04-01 | 北京桑德环境工程有限公司 | Treatment system and method for biogas slurry produced from anaerobic fermentation of kitchen waste |
| CN104909502A (en) * | 2015-06-24 | 2015-09-16 | 南京元凯生物能源环保工程有限公司 | Biogas slurry pretreatment method |
| CN105129946A (en) * | 2015-09-14 | 2015-12-09 | 镇江华立煤质制样设备有限公司 | Efficient coal-washing wastewater treatment agent |
| CN111233167A (en) * | 2020-01-21 | 2020-06-05 | 中国科学院成都生物研究所 | Alcaligenes faecalis and application thereof in chicken manure biogas slurry flocculation |
| CN112794555A (en) * | 2020-12-23 | 2021-05-14 | 联合环境技术(天津)有限公司 | Novel method for treating wastewater by reinforced coagulation |
| CN216129468U (en) * | 2021-08-11 | 2022-03-25 | 北京航天威科环保科技有限公司 | A concentrated system that is used for animal manure anaerobic fermentation natural pond liquid |
Non-Patent Citations (2)
| Title |
|---|
| 于洪淼等: "化学絮凝法处理海产品加工中高浓度含磷废水", 《水资源与水工程学报》 * |
| 杨西昭: "乙醇沼气双发酵耦联工艺中中温出水水质调控及中试验证", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 * |
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