Disclosure of Invention
The invention aims to solve the defects of the prior art and provides a domestic sewage treatment method by matching a composite microbial inoculum with an artificial wetland.
In order to achieve the purpose, the invention adopts the following technical scheme:
a domestic sewage treatment method by combining a composite microbial inoculum with an artificial wetland comprises the following specific steps:
step one, strain culture, namely inoculating pseudomonas, bacillus, nitrobacter, nitrosomonas and bacillus megatherium respectively into a sterilized domestic sewage culture medium for culture, and culturing under the conditions that the temperature is 15 ℃ and the rotating speed of a shaking table is 130r/min until the number of bacteria of the bacteria liquid reaches 3.6 multiplied by 10 in sequence8-9.3×108Is/areml，2.5×108-7.8×1081.5X 10 units/ml8-6.6×108Each/ml, 5.0X 108-6.8×108One/ml and 2.5X 108-8.6×108Per ml;
step two, preparing composite bacteria, namely mixing the bacterial liquid of pseudomonas with the bacterial liquid of bacillus to prepare COD degrading composite bacteria; mixing a bacterial liquid of nitrobacillus with a bacterial liquid of nitrosomonas to prepare nitronitrosomonas composite bacteria, wherein the bacterial liquid of bacillus megatherium is phosphorus-removing bacteria;
step three, preparing a composite microbial inoculum, namely mixing the COD degrading composite bacteria, the nitrifying-nitrosating composite bacteria and the phosphorus removing bacteria prepared in the step two according to the volume ratio of 10 (0.25-4) to 0.5 under the condition of the same bacteria number to prepare the composite microbial inoculum;
step four, domesticating the composite microbial inoculum prepared in the step three, and mixing the composite microbial inoculum with artificial water according to the volume ratio of 1: 1, uniformly mixing to obtain a mixed solution, adding the mixed solution into a filler reactor, continuously performing acclimation culture under the conditions that the temperature is 25-30 ℃ and the dissolved oxygen DO is 2.5-2.6mg/L, wherein the acclimation culture is performed according to an acclimation system with water inflow of 10-15min, aeration of 11-12h, sedimentation of 10-15min, drainage of 10-15min and standing of 30-45min as an acclimation period, two periods are operated every day, the hydraulic retention time is 10-12h, and the continuous acclimation is carried out for 28-32 days to prepare the acclimated composite microbial inoculum;
and step five, treating the domestic sewage, namely pretreating the domestic sewage through a reclaimed water station, feeding the pretreated secondary effluent into the subsurface flow artificial wetland, adding the domesticated composite microbial inoculum prepared in the step four into the subsurface flow artificial wetland, and allowing the sewage to stay in the subsurface flow artificial wetland for 7-9 days in a hydraulic manner.
Further, the height of the polyurethane filler in the filler reactor in the fourth step accounts for 1/3 the height of the inner cavity of the reactor and is always in a fluidized state.
Further, the density of the polyurethane filler in the fourth step is 0.015-0.03g/cm3Surface area of 5000cm2Per g, porosity>95 percent, and the aperture is 2-2.5 mm.
Further, in the artificial water distribution in the fourth step, the concentration of disodium hydrogen phosphate is 7.9g/L, the concentration of potassium nitrate is 1.8g/L, the concentration of monopotassium phosphate is 1.5g/L, the concentration of disodium succinate is 4.2g/L, the concentration of ammonium sulfate is 0.3g/L, the concentration of magnesium sulfate crystals is 0.1g/L, the concentration of trace element additive is 2mL/L, and the pH value is 7.2-7.5.
And further, the subsurface flow constructed wetland in the fifth step is an artificial wetland for planting reeds, and the constructed wetland comprises a rubble layer, an impermeable layer, a combined filler layer, a ceramsite layer and a surface mature soil layer from bottom to top in sequence.
The invention has the beneficial effects that: the microbial inoculum is acclimatized and cultured adaptively before being put into the culture tank, so that the microbial inoculum is stronger in adaptability and better in treatment effect; the capital cost is low, the operation management is convenient, the treatment cost is low, and the treatment cost per ton of water is only 0.33-0.39 yuan; the invention selects the porcelain granules as the novel filler of the artificial wetland, is favorable for better fixing rhizosphere microorganisms and better exerting the action of the microorganisms, and selects the reed with rich rhizosphere microorganisms as the wetland plant, thereby having good effect of removing organic matters, nitrogen and phosphorus. The sewage ammonia nitrogen conversion rate can reach 95%, the total nitrogen conversion rate reaches 82%, the COD conversion rate reaches 60%, and the total phosphorus conversion rate can reach about 75%.
Detailed Description
The invention is further illustrated by the following examples:
example one
A domestic sewage treatment method by combining a composite microbial inoculum with an artificial wetland comprises the following specific steps:
step one, strain culture, namely inoculating pseudomonas, bacillus, nitrobacter, nitrosomonas and bacillus megatherium respectively into a sterilized domestic sewage culture medium for culture, and culturing under the conditions that the temperature is 15 ℃ and the rotating speed of a shaking table is 130r/min until the number of bacteria of the bacteria liquid reaches 3.6 multiplied by 10 in sequence82.5X 10 units/ml81.5X 10 units/ml8Each/ml, 5.0X 108One/ml and 2.5X 108Per ml;
step two, preparing composite bacteria, namely mixing the bacterial liquid of pseudomonas with the bacterial liquid of bacillus to prepare COD degrading composite bacteria; mixing a bacterial liquid of nitrobacillus with a bacterial liquid of nitrosomonas to prepare nitronitrosomonas composite bacteria, wherein the bacterial liquid of bacillus megatherium is phosphorus-removing bacteria;
step three, preparing a composite microbial inoculum, namely mixing the COD degrading composite bacteria, the nitrifying-nitrosating composite bacteria and the phosphorus removing bacteria prepared in the step two according to the volume ratio of 10:0.25:0.5 under the condition of the same bacteria number to prepare the composite microbial inoculum;
step four, domesticating the composite microbial inoculum prepared in the step three, and mixing the composite microbial inoculum with artificial water according to the volume ratio of 1: 1, uniformly mixing to obtain a mixed solution, adding the mixed solution into a filler reactor, continuously performing acclimatization culture under the conditions that the temperature is 25 ℃ and the dissolved oxygen DO is 2.5mg/L, wherein the acclimatization culture is performed according to an acclimatization system with water inflow of 10min, aeration of 11h, sedimentation of 10min, drainage of 10min and standing of 30min as an acclimatization period, two periods are operated every day, the hydraulic retention time is 10h, and the continuous acclimatization is carried out for 28 days to prepare an acclimatized composite microbial inoculum;
and step five, treating the domestic sewage, namely pretreating the domestic sewage through a reclaimed water station, feeding the pretreated secondary effluent into the subsurface flow artificial wetland, adding the domesticated composite microbial inoculum prepared in the step four into the subsurface flow artificial wetland, and allowing the sewage to stay in the subsurface flow artificial wetland for 7 days in a hydraulic manner.
Further, the height of the polyurethane filler in the filler reactor in the fourth step accounts for 1/3 the height of the inner cavity of the reactor and is always in a fluidized state.
Further, the density of the polyurethane filler in the fourth step is 0.015g/cm3Surface area of 5000cm2Per g, porosity>95 percent and the aperture is 2 mm.
Furthermore, in the artificial water distribution in the fourth step, the concentration of disodium hydrogen phosphate is 7.9g/L, the concentration of potassium nitrate is 1.8g/L, the concentration of monopotassium phosphate is 1.5g/L, the concentration of disodium succinate is 4.2g/L, the concentration of ammonium sulfate is 0.3g/L, the concentration of magnesium sulfate crystals is 0.1g/L, the concentration of trace element additive is 2mL/L, and the pH value is 7.2.
And further, the subsurface flow constructed wetland in the fifth step is an artificial wetland for planting reeds, and the constructed wetland comprises a rubble layer, an impermeable layer, a combined filler layer, a ceramsite layer and a surface mature soil layer from bottom to top in sequence.
Example two
A domestic sewage treatment method by combining a composite microbial inoculum with an artificial wetland comprises the following specific steps:
step one, strain culture, namely inoculating pseudomonas, bacillus, nitrobacter, nitrosomonas and bacillus megatherium respectively into a sterilized domestic sewage culture medium for culture, and culturing under the conditions that the temperature is 15 ℃ and the rotating speed of a shaking table is 130r/min until the number of bacteria of the bacteria liquid reaches 9.3 multiplied by 10 in sequence8One/ml, 7.8X 1086.6X 10 units/ml86.8X 10 cells/ml8One/ml and 8.6X 108Per ml;
step two, preparing composite bacteria, namely mixing the bacterial liquid of pseudomonas with the bacterial liquid of bacillus to prepare COD degrading composite bacteria; mixing a bacterial liquid of nitrobacillus with a bacterial liquid of nitrosomonas to prepare nitronitrosomonas composite bacteria, wherein the bacterial liquid of bacillus megatherium is phosphorus-removing bacteria;
step three, preparing a composite microbial inoculum, namely mixing the COD degrading composite bacteria, the nitrifying-nitrosating composite bacteria and the phosphorus removing bacteria prepared in the step two according to the volume ratio of 10:4:0.5 under the condition of the same bacteria number to prepare the composite microbial inoculum;
step four, domesticating the composite microbial inoculum prepared in the step three, and mixing the composite microbial inoculum with artificial water according to the volume ratio of 1: 1, uniformly mixing to obtain a mixed solution, adding the mixed solution into a filler reactor, continuously performing acclimatization culture under the conditions that the temperature is 30 ℃ and the dissolved oxygen DO is 2.6mg/L, wherein the acclimatization culture is performed according to an acclimatization system with 15min of water inlet, 12h of aeration, 15min of sedimentation, 15min of water drainage and 45min of standing as an acclimatization period, two periods are operated every day, the hydraulic retention time is 12h, and the continuous acclimatization is carried out for 32 days to prepare an acclimatized composite microbial inoculum;
and step five, treating the domestic sewage, namely pretreating the domestic sewage through a reclaimed water station, feeding the pretreated secondary effluent into the subsurface flow artificial wetland, adding the domesticated composite microbial inoculum prepared in the step four into the subsurface flow artificial wetland, and allowing the sewage to stay in the subsurface flow artificial wetland for 9 days in a hydraulic manner.
Further, the height of the polyurethane filler in the filler reactor in the fourth step accounts for 1/3 the height of the inner cavity of the reactor and is always in a fluidized state.
Further, the density of the polyurethane filler in the fourth step is 0.03g/cm3Surface area of 5000cm2Per g, porosity>95 percent and the aperture is 2.5 mm.
Furthermore, in the artificial water distribution in the fourth step, the concentration of disodium hydrogen phosphate is 7.9g/L, the concentration of potassium nitrate is 1.8g/L, the concentration of monopotassium phosphate is 1.5g/L, the concentration of disodium succinate is 4.2g/L, the concentration of ammonium sulfate is 0.3g/L, the concentration of magnesium sulfate crystals is 0.1g/L, the concentration of trace element additive is 2mL/L, and the pH value is 7.5.
And further, the subsurface flow constructed wetland in the fifth step is an artificial wetland for planting reeds, and the constructed wetland comprises a rubble layer, an impermeable layer, a combined filler layer, a ceramsite layer and a surface mature soil layer from bottom to top in sequence.
EXAMPLE III
A domestic sewage treatment method by combining a composite microbial inoculum with an artificial wetland comprises the following specific steps:
step one, strain culture, namely inoculating pseudomonas, bacillus, nitrobacter, nitrosomonas and bacillus megatherium respectively into a sterilized domestic sewage culture medium for culture, and culturing under the conditions that the temperature is 15 ℃ and the rotating speed of a shaking table is 130r/min until the number of bacteria of the bacteria liquid reaches 5 multiplied by 10 in sequence85X 10 units/ml85X 10 units/ml86X 10 units/ml8One/ml and 6.6X 108Per ml;
step two, preparing composite bacteria, namely mixing the bacterial liquid of pseudomonas with the bacterial liquid of bacillus to prepare COD degrading composite bacteria; mixing a bacterial liquid of nitrobacillus with a bacterial liquid of nitrosomonas to prepare nitronitrosomonas composite bacteria, wherein the bacterial liquid of bacillus megatherium is phosphorus-removing bacteria;
step three, preparing a composite microbial inoculum, namely mixing the COD degrading composite bacteria, the nitrifying-nitrosating composite bacteria and the phosphorus removing bacteria prepared in the step two according to the volume ratio of 10:1:0.5 under the condition of the same bacteria number to prepare the composite microbial inoculum;
step four, domesticating the composite microbial inoculum prepared in the step three, and mixing the composite microbial inoculum with artificial water according to the volume ratio of 1: 1, uniformly mixing to obtain a mixed solution, adding the mixed solution into a filler reactor, continuously performing acclimatization culture under the conditions that the temperature is 26 ℃ and the dissolved oxygen DO is 2.55mg/L, wherein the acclimatization culture is performed according to an acclimatization system with 12min of water inlet, 11.5h of aeration, 12min of sedimentation, 11min of water drainage and 33min of standing as an acclimatization period, two periods are operated every day, the hydraulic retention time is 11h, and the continuous acclimatization is carried out for 29 days to prepare an acclimatized composite microbial inoculum;
and step five, treating the domestic sewage, namely pretreating the domestic sewage through a reclaimed water station, feeding the pretreated secondary effluent into the subsurface flow artificial wetland, adding the domesticated composite microbial inoculum prepared in the step four into the subsurface flow artificial wetland, and allowing the sewage to stay in the subsurface flow artificial wetland for 8 days in a hydraulic manner.
Further, the height of the polyurethane filler in the filler reactor in the fourth step accounts for 1/3 the height of the inner cavity of the reactor and is always in a fluidized state.
Further, the density of the polyurethane filler in the fourth step is 0.02g/cm3Surface area of 5000cm2Per g, porosity>95 percent and the aperture is 2.2 mm.
Furthermore, in the artificial water distribution in the fourth step, the concentration of disodium hydrogen phosphate is 7.9g/L, the concentration of potassium nitrate is 1.8g/L, the concentration of monopotassium phosphate is 1.5g/L, the concentration of disodium succinate is 4.2g/L, the concentration of ammonium sulfate is 0.3g/L, the concentration of magnesium sulfate crystals is 0.1g/L, the concentration of trace element additive is 2mL/L, and the pH value is 7.3.
And further, the subsurface flow constructed wetland in the fifth step is an artificial wetland for planting reeds, and the constructed wetland comprises a rubble layer, an impermeable layer, a combined filler layer, a ceramsite layer and a surface mature soil layer from bottom to top in sequence.
The microbial inoculum is acclimatized and cultured adaptively before being put into the culture tank, so that the microbial inoculum is stronger in adaptability and better in treatment effect; the capital cost is low, the operation management is convenient, the treatment cost is low, and the treatment cost per ton of water is only 0.33-0.39 yuan; the invention selects the porcelain granules as the novel filler of the artificial wetland, is favorable for better fixing rhizosphere microorganisms and better exerting the action of the microorganisms, and selects the reed with rich rhizosphere microorganisms as the wetland plant, thereby having good effect of removing organic matters, nitrogen and phosphorus. The sewage ammonia nitrogen conversion rate can reach 95%, the total nitrogen conversion rate reaches 82%, the COD conversion rate reaches 60%, and the total phosphorus conversion rate can reach about 75%.
The present invention has been described in connection with the specific embodiments, and it is obvious that the specific implementation of the present invention is not limited by the above-mentioned manner, and it is within the protection scope of the present invention as long as various modifications are made by using the method concept and technical solution of the present invention, or the present invention is directly applied to other occasions without modification.