Method for preparing organic fertilizer by using domestic sludge and reaction kettle

Abstract

The present application belongs to the technical field of sludge treatment, and particularly relates to a method for preparing organic fertilizer by using domestic sludge and a reaction kettle. The method for preparing organic fertilizer by using domestic sludge comprises the following steps: mixing domestic sludge with an acid solution, stirring and heating the mixture, allowing the domestic sludge to react with the acid solution, separating the reacted mixture into dry materials and liquid by using a separation device, mixing the dry materials with dry cow dung to form a base material, adding wheat bran and urea into the base material, and allowing the base material to ferment to form organic fertilizer. The method can harmlessly treat domestic sludge, convert the domestic sludge from organic waste into organic fertilizer, and prevent the domestic sludge from polluting the land and air. The treatment method is simple to operate and low in cost, and thus effectively solves the problem of pollution of the soil quality and air caused by domestic sludge.

Description

Technical Field

[0001] The invention belongs to the technical field of sludge treatment, and particularly relates to a method for preparing organic fertilizer by utilizing domestic sludge and a reactor. Background Art

[0002] With the rapid growth of the number of sewage treatment plants in my country, the amount of sludge in my country is currently increasing at a rate of 10% per year.

[0003] Generally, the sludge in large sewage treatment plants is mostly treated by incineration to render it harmless. The heat energy generated during the incineration process can be recycled, and the sludge volume and quantity can be reduced to a high degree. However, incineration requires huge investment, complex operation and management, and high energy consumption and operating costs. It does not yet have a basis for comprehensive promotion in my country, and the sludge treatment problem has become an environmental problem that urgently needs to be solved in my country. Therefore, providing a low-cost and harmless method for treating domestic sludge is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a method for preparing organic fertilizer using domestic sludge to solve the technical problems existing in the prior art of high treatment cost of domestic sludge and environmental impact.

[0005] The present invention is specifically implemented through the following technical solutions:

[0006] A method for preparing organic fertilizer from domestic sewage sludge comprises the following steps:

[0007] S1: adding domestic sludge and acidic solution into the reactor body, so that the domestic sludge and acidic solution are mixed in the reactor body to form a fluid mixture;

[0008] S2: heating and stirring the mixed material in the kettle to make the domestic sludge react with the acid solution;

[0009] S3: sending the reacted mixed material to a separation device, where the reacted mixed material is separated into dry material and liquid;

[0010] S4: The dry material is mixed with dry cow dung to form a base material, and wheat bran and urea are added to the base material to ferment the base material to form organic fertilizer.

[0011] In order to better implement the present invention, further optimization is made in the above structure. The ratio of domestic sludge to acidic solution in step S1 is 1:0.8-2.5, and the pH value of the mixture is 2-4.

[0012] In order to better realize the present invention, further optimization is made in the above structure, and the acidic solution is hydrochloric acid, sulfuric acid or furfural waste liquid.

[0013] In order to better implement the present invention, further optimization is made in the above structure, the heating temperature in step S2 is 60-100 degrees Celsius, and the stirring time is 1-3 hours.

[0014] In order to better implement the present invention, further optimization is made in the above structure, and step S4 also includes T40, T40: adding fermentation bacteria to the base material to accelerate the fermentation speed of the base material.

[0015] In order to better implement the present invention, further optimization is made in the above structure, the ratio of dry material to dry cow dung in step S4 is 1:1.5-2, and the moisture content in the base material is 30%-50%.

[0016] In summary, the method for preparing organic fertilizer from domestic sewage sludge provided by the present invention has the following technical effects:

[0017] This method can harmlessly treat domestic sludge, converting it from organic waste into organic fertilizer so that domestic sludge no longer pollutes the land and air. The domestic sludge treatment method is simple to operate and low in cost, thereby effectively solving the problem of domestic sludge polluting soil quality and air.

[0018] The present invention also provides a reaction kettle, comprising a kettle body, a heating device, a stirring device and a separating device;

[0019] The kettle body is provided with a feeding port and a discharging port, the heating device is communicated with the interior of the kettle body, the discharging port is provided with a valve for opening / closing the discharging port, and the stirring device is provided in the kettle body;

[0020] The separation device is arranged at the discharge port.

[0021] In order to better realize the present invention, further optimization is made in the above structure. The stirring device includes a stirring motor, a reducer and a stirring rod. The stirring end of the stirring rod is arranged in the kettle body, and the stirring motor is connected to the stirring rod through the reducer.

[0022] In order to better realize the present invention, further optimization is made in the above structure. The reactor also includes a first conveying device and a second conveying device. The discharge port is connected to the separation device through the first conveying device, and the input end of the second conveying device is arranged at the discharge end of the separation device.

[0023] In order to better realize the present invention, further optimization is made in the above structure. The separation device includes a solid material outlet and a liquid material outlet. The input end of the second conveying device is arranged at the fixed discharge port. A water reservoir is provided at the liquid material outlet. The water reservoir is connected to the reactor through a return water pipeline.

[0024] In summary, the reactor provided by the present invention has the following technical effects:

[0025] The reactor can complete the processes of mixing, heating and separating domestic sludge and acidic solution, so that the process of using domestic sludge to make organic fertilizer becomes simpler and the production efficiency of organic fertilizer is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a flow chart of a method for preparing organic fertilizer using domestic sewage sludge according to the present invention;

[0028] Figure 2 It is a structural schematic diagram of a reactor of the present invention.

[0029] Reference numerals:

[0030] 1. Kettle body; 2. Heating device; 3. Stirring device; 4. Separating device; 51. First conveying device; 52. Second conveying device; 6. Water reservoir; 7. Return water pipeline. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0032] Example 1:

[0033] like Figure 1 and Figure 2 As shown:

[0034] A method for preparing organic fertilizer from domestic sewage sludge comprises the following steps:

[0035] S1: adding the domestic sludge and the acid solution into a kettle body 1 of a reaction kettle, and mixing the domestic sludge and the acid solution in the kettle body 1 to form a fluid mixture;

[0036] S2: heating and stirring the mixture in the kettle body 1 to make the domestic sludge react with the acid solution;

[0037] S3: sending the reacted mixture to a separation device 4, and separating the reacted mixture into dry materials and liquid by the separation device 4;

[0038] S4: mixing the dry materials with dry cow dung to form a base material, and adding wheat bran and urea into the base material to ferment the base material to form the organic fertilizer.

[0039] The method for preparing the organic fertilizer from the domestic sludge can harmlessly treat the domestic sludge, and convert the domestic sludge from organic waste into the organic fertilizer, so that the domestic sludge no longer pollutes the land and the air, and the treatment method is simple in operation and low in cost, thereby effectively solving the pollution of the domestic sludge to the soil quality and the air.

[0040] In an optimization, the ratio of the domestic sludge to the acid solution in the step S1 is 1:0.8-2.5, so that the PH value of the mixture is 2-4.

[0041] In an optimization, the heating temperature in the step S2 is between 60 and 100 degrees Celsius; when the mixture is below 60 degrees Celsius, the domestic sludge and the acid solution hardly react, and when the temperature of the mixture is above 100 degrees Celsius, the mixture locally boils, the ammonia-nitrogen compound in the mixture decomposes and is lost, and the nutrient of the mixture as a whole is reduced; therefore, the heating temperature of the mixture is between 60 and 100 degrees Celsius, which is the most appropriate.

[0042] In addition, through repeated tests, the reaction time of the mixture is positively correlated with the heating temperature, that is, the higher the heating temperature (within the range of 60-100 degrees Celsius), the faster the reaction of the mixture; therefore, the heating temperature can be as high as possible under the condition of controlling the cost, so as to effectively improve the reaction speed of the mixture.

[0043] Preferably, the acid solution can be hydrochloric acid, sulfuric acid or organic acid, etc.; because most sewage treatment plants use polyacrylamide (non-ionic) as a flocculant, if an alkaline solution is used for treatment, the alkaline solution will cause the polyacrylamide to have a chain structure, and the monomer is acrylamide, which is a toxic nerve agent, and it cannot be used as a material for making organic fertilizer, therefore the above-mentioned solution must use an acid solution.

[0044] More preferably, the above-mentioned acidic solution is furfural waste liquid; the furfural waste liquid is the waste acid liquid generated after the furfural production in the furfural plant, and the furfural waste liquid can simultaneously meet the requirements of a reaction temperature greater than 60 degrees Celsius and a pH value less than 4, so that the furfural waste liquid can react well with the domestic sludge, and the acetic acid contained in the furfural waste liquid can effectively integrate the odor of the sludge itself, thereby realizing the dual waste utilization of the furfural waste liquid and the domestic sludge, so as to better solve the problem of environmental pollution caused by the furfural waste liquid and the domestic sludge.

[0045] Optimally, the separation method in the above step S3 can be centrifugal separation or vacuum filtration, that is, it can separate the dry material from the liquid.

[0046] Preferably, the liquid separated by centrifugal separation or vacuum filtration can be reused; in the above method, a suction device is used to send the separated liquid back into the reactor, and mix and react with the newly added domestic sludge to improve the utilization rate of the waste, thereby effectively reducing the treatment cost of domestic sludge.

[0047] Optimally, the ratio of dry material to dry cow dung in the above-mentioned step S4 is 1:1.5-2, and the moisture content of the base material is maintained at 30%-50%, and then wheat bran and urea are added to the base material to make the carbon-nitrogen ratio in the base material 16:1, thereby ensuring the requirements of the life activities of the microorganisms in the base material and enabling the base material to ferment better.

[0048] Preferably, S4 further includes T40;

[0049] T40: Add fermentation bacteria to the base material to increase the fermentation speed of the base material and effectively improve the fermentation effect.

[0050] Optimally, the method for preparing organic fertilizer using domestic sewage sludge further comprises step T41;

[0051] T41: The base material is left to stand for secondary aging, while the powdered organic fertilizer is directly packaged into powdered organic fertilizer; the granular organic fertilizer needs to be made into a granule and then packaged.

[0052] Example 2:

[0053] like Figure 2 As shown:

[0054] A reaction kettle, comprising a kettle body 1, a heating device 2, a stirring device 3 and a separating device 4;

[0055] The kettle body 1 is provided with a feeding port and a discharging port, the heating device 2 is connected to the interior of the kettle body 1, a valve for opening / closing the discharging port is provided at the discharging port, and the stirring end of the stirring device 3 is provided in the kettle body 1;

[0056] The separation device 4 is arranged at the discharge port of the kettle body 1 .

[0057] The reactor can complete the mixing, heating and separation of domestic sewage sludge and acidic solution, so that the process of using domestic sewage sludge to make organic fertilizer becomes simpler and the production efficiency of organic fertilizer is effectively improved.

[0058] Optimally, the stirring device 3 includes a stirring motor, a reducer and a stirring rod; wherein,

[0059] The stirring rod is rotatably arranged on the kettle body 1, and the stirring end of the stirring rod is located inside the kettle body 1. The stirring motor is connected to the stirring rod through a reducer, so that the stirring motor can drive the stirring rod to rotate through the reducer to stir the mixed material in the kettle body 1, so that the domestic sludge and the acidic solution are mixed more evenly; and the setting of the reducer can increase the torque of the stirring rod, so that the stirring device 3 can better complete the stirring of the mixed material.

[0060] Optimally, the reactor further comprises a first conveying device 51 and a second conveying device 52; wherein,

[0061] The input end of the first conveying device 51 is set at the discharge end of the kettle body 1, and the output end of the first conveying device 51 is set at the feed end of the separation device 4, so that the mixed material output by the kettle body 1 can be transported to the separation device 4 through the first conveying device 51; and the second conveying device 52 is set at the discharge end of the separation device 4, so that the second conveying device 52 can transport the dry material separated by the separation device 4 to the dry material stacking area, so as to facilitate the next step of operation on the dry material.

[0062] Preferably, the separation device 4 includes a solid material outlet and a liquid material outlet, and the input end of the second conveying device 52 is arranged at the solid material outlet, so that the second conveying device 52 can convey the dry material output by the separation device 4 to the dry material storage area;

[0063] A water reservoir 6 is provided at the outlet of the liquid material, and the water reservoir 6 is connected to the kettle body 1 through a return pipe 7, so that the return pipe 7 can transport the liquid separated and output by the separation device 4 into the kettle body 1, so that the liquid can be reused, thereby improving the utilization rate of waste and effectively reducing the treatment cost of domestic sludge.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing organic fertilizer from domestic sewage sludge, characterized in that: The following steps are involved: S1: adding domestic sludge and acidic solution into the reactor body (1) to mix the domestic sludge and acidic solution in the reactor body (1) to form a fluid mixture; S2: heating and stirring the mixed material in the kettle (1) to allow the domestic sludge to react with the acidic solution; S3: sending the reaction mixture to the separation device (4), and separating the reaction mixture into dry material and liquid by the separation device (4); S4: mixing the dry material with dry cow dung to form a base material, and adding wheat bran and urea to the base material to ferment the base material to form organic fertilizer; In step S1, the ratio of domestic sludge to acidic solution is 1:0.8-2.5, and the pH value of the mixture is 2-4; The acidic solution is hydrochloric acid, sulfuric acid or furfural waste liquid; The heating temperature in step S2 is 60-100 degrees Celsius, and the stirring time is 1-3 hours; Step S4 also includes T40: adding fermentation bacteria to the base material to accelerate the fermentation speed of the base material.

2. The method for preparing organic fertilizer from domestic sewage sludge according to claim 1, wherein: The ratio of dry material to dry cow dung in step S4 is 1:1.5-2, and the moisture content in the base material is 30%-50%.

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