阅读说明：本技术 一种易腐垃圾发酵制肥的系统工艺方法 (System and process method for preparing fertilizer by fermenting perishable garbage ) 是由 贾书亚 于 2018-06-13 设计创作，主要内容包括：本发明涉及固体废弃物处理技术领域,具体涉及一种易腐垃圾发酵制肥的系统工艺方法。该方法将待处理垃圾首先进行破碎分选处理,剔除难腐有机物；然后加入水调节其固含量,制成浆料,在浆料中通入微米气泡。最大限度剔除塑料、织物等难腐有机物,和玻璃、陶瓷、砂石、金属等不腐无机物。可以有效降低与稳定控制垃圾衍生肥料中重金属含量,消除了垃圾衍生肥料中重金属含量的不确定性,为解决垃圾衍生肥料的出路打开方便之门。而且下沉分离出的比重大的泥砂类的物料中有机质和水分含量低,符合直接填埋和用作建筑材料的原料的要求。(The invention relates to the technical field of solid waste treatment, in particular to a systematic process method for preparing fertilizer by fermenting perishable garbage. The method comprises the steps of firstly, crushing and sorting the garbage to be treated to remove organic matters which are difficult to corrode; then water is added to adjust the solid content of the mixture to prepare slurry, and micron bubbles are introduced into the slurry. The method can remove the refractory organics such as plastics and fabrics and the non-corrosive inorganics such as glass, ceramics, sand and stone and metal to the maximum extent. The method can effectively reduce and stably control the content of heavy metals in the refuse derived fertilizer, eliminates the uncertainty of the content of heavy metals in the refuse derived fertilizer, and is a convenient door for opening the way of the refuse derived fertilizer. And the settled and separated mud and sand materials with high specific gravity have low organic matter and moisture content, thus meeting the requirements of direct landfill and being used as raw materials of building materials.)

1. A systematic process method for preparing fertilizer by fermenting perishable garbage is characterized by comprising the following operation steps:

1) crushing and sorting the garbage to be treated to obtain primary separated garbage;

2) adding water into the primarily separated garbage obtained in the step 1) to adjust the solid content of the primarily separated garbage to prepare slurry, continuously introducing micro bubbles into the slurry, floating materials with light specific gravity in the slurry under the action of the micro bubbles, settling mud and sand materials with high specific gravity, and suspending perishable organic matters in the middle; removing the floating materials on the upper layer and the settled materials on the lower layer to obtain slurry containing perishable organic matters;

3) carrying out filter pressing treatment on the slurry containing the perishable organic matters obtained in the step 2), and separating to obtain perishable organic matters and filtrate; aerobic fermentation treatment is carried out on the perishable organic matters to prepare the organic fertilizer raw material.

2. A systematic process method for preparing fertilizer by fermenting perishable garbage according to claim 1, wherein the filtrate obtained in step 3) is subjected to flocculation and precipitation treatment, organic matters in the filtrate are recovered, and the filtrate is returned to step 2) to be used as a water source for adjusting the solid content of the primarily separated garbage; mixing the organic matters in the recovered filtrate with the perishable organic matters separated in the step 3) for aerobic fermentation treatment.

3. A systematic process for making fertilizer by fermentation of perishable waste as in claim 1 wherein the heavy metal content of the filtrate that is controlled back to step 2) as the source of water is less than 80% of the heavy metal content required by national standard NY 525-2012.

4. A systematic process method for making fertilizer by fermenting perishable wastes as defined in claim 1, wherein the solid content of the primarily separated wastes is adjusted to 5-10% in the step 2).

5. A systematic process for preparing fertilizer by fermenting perishable garbage according to claim 1, wherein the specific method for crushing and sorting the garbage to be treated in the step 1) is as follows: firstly, shredding garbage to be treated and screening the garbage to be treated to obtain garbage materials with the particle size of less than 200mm, and feeding the separated large materials into an RDF treatment system; and then selectively crushing the garbage materials with the particle size of less than 200mm, crushing perishable garbage and fragile large inorganic substance components in the garbage, and simultaneously screening and separating to obtain the garbage materials with the particle size of less than 20mm, namely primary separated garbage.

6. The systematic process method for preparing fertilizer by fermenting perishable garbage according to claim 1, wherein in the step 3), the water content of the perishable organic matters obtained by controlling and separating the slurry containing the perishable organic matters obtained in the step 2) is subjected to filter pressing treatment, and is 60-80%.

7. A systematic process method for preparing fertilizer by fermenting perishable garbage according to claim 1, wherein the aerobic fermentation treatment in the step 3) is closed dynamic aerobic fermentation, and the fermentation time is 3-4 days.

8. A systematic process method for preparing fertilizer by fermenting perishable garbage according to claim 1, wherein the large garbage, the plastic, the fabric and the rubber which are not easy to break and separated in the step 1) and the upper floating material removed in the step 2) enter an RDF energy conversion system for resource recycling; and 2) performing landfill treatment on the lower-layer settled material removed in the step 2) or using the lower-layer settled material as a raw material for building material production.

Technical Field

The invention relates to the technical field of solid waste treatment, in particular to a systematic process method for preparing fertilizer by fermenting perishable garbage.

Background

With the implementation of the national garbage classification policy, the wet garbage (mainly kitchen garbage), kitchen garbage, vegetable and fruit garbage in the professional market can be separated from the household garbage firstly, and the desire of social development for the garbage treatment is shown. The water content of the garbage is high and is usually 60-90%, and the garbage is mixed with difficultly rotten and large organic matters such as plastics, fabrics, paper, bamboo and wood, and inorganic inert substances such as silt, stones, cement blocks, glass and the like; and metals such as stainless steel, bottle caps and the like, and even toxic and harmful wastes such as batteries, lamp tubes and the like. The classified wet garbage and the classified vegetable and fruit professional market have high moisture content of the perishable garbage, fast decay and deterioration, and the odor emission and the leachate outflow bring huge pollution to the environment, which troubles the improvement of the resident life and urban environment for a long time. The wet garbage is not suitable for landfill, has no soil landfill, has low heat value and cannot be directly incinerated.

Perishable organic fertilizer production has been a consistent practice for thousands of years. However, with the development of the petrochemical, rubber and synthetic materials industries, in particular the modern chemical industry, the simple composting of wet kitchen waste with mixed properties in the food market, the fruit market and the residential kitchen has failed after decades of practice. Although the gasification for preparing the biogas by fermentation is also an available resource method, the wet anaerobic process or the dry anaerobic process can only realize partial resource conversion, the treatment of the biogas slurry and the biogas residues becomes an industry pain point, and the normal operation of the project is restricted for a long time. Also, the investment is high, and the economical efficiency and sustainability are greatly reduced. Because the heavy metal content in the wet garbage raw materials is uncertain, the heavy metal content in the fertilizer obtained by simple composting is uncertain, and even the situation of exceeding the standard can occur in most cases, so that the national policy of leaving the platform does not allow garbage derived fertilizers to enter food chain production, and the wet garbage can not be reasonably and effectively recycled.

Toxic and harmful elements from natural organic matters do not exceed the standard, and the toxic and harmful elements are the mixture of various wastes and the action of liquid generated after the putrescible organic matters decay, so that heavy metals are migrated from other garbage components to final products to cause the result that the heavy metals in the garbage derived fertilizer exceed the standard. The instability of garbage components is a main factor causing uncertainty of contents of toxic and harmful elements such as heavy metals and the like in the garbage derived fertilizer. The separation of the organic matter components difficult to corrode in the garbage is an important measure for cutting off the heavy metal source. In the prior art, separation treatment of materials before fermentation also appears, migration of harmful components such as non-organic matters in garbage raw materials or heavy metals in materials difficult to corrode in the fermentation process is reduced, natural sedimentation treatment is carried out after water is added into the materials to be treated in the traditional mode, separation of all components cannot be rapidly realized, efficiency is too low, and engineering value is not available. The improved method is based on the traditional mode and realizes separation by simply blowing gas, the separation can improve the separation efficiency to a certain extent, but fine plastics, fabric fluff pieces and silt are difficult to completely separate, so that the separated organic matter still contains silt, difficultly rotten plastics, fabrics and other materials, the content of the organic matter in the silt is high, the quality of the materials after aerobic fermentation cannot be guaranteed, and the settled materials such as the silt cannot meet the landfill standard and cannot be directly buried.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a systematic process method for preparing fertilizer by fermenting perishable garbage, and the prepared fertilizer has stable quality and low pollutant emission in the process.

A systematic process method for preparing fertilizer by fermenting perishable garbage comprises the following operation steps:

1) crushing and sorting the garbage to be treated, crushing perishable organic matters and inorganic matters, and separating out difficultly rotten organic matters such as plastics, rubber, fabrics and the like to obtain primary separated garbage;

2) adding water into the primarily separated garbage obtained in the step 1) to adjust the solid content of the primarily separated garbage to prepare slurry, continuously introducing micro bubbles into the slurry, floating materials with light specific gravity in the slurry under the action of the micro bubbles, settling mud and sand materials with high specific gravity, and suspending perishable organic matters in the middle; removing the floating materials on the upper layer and the settled materials on the lower layer to obtain slurry containing perishable organic matters;

3) carrying out filter pressing treatment on the slurry containing the perishable organic matters obtained in the step 2), and separating to obtain perishable organic matters and filtrate; aerobic fermentation treatment is carried out on the perishable organic matters to prepare the organic fertilizer raw material.

The filtrate obtained in the step 3) contains organic suspended matters and organic putrefactive and semi-putrefactive products, and the direct recycling can reduce the flotation efficiency of micron bubbles introduced in the step 2), and influence the extraction rate of organic matters and the stable quality of the prepared organic fertilizer raw materials in the whole process. Therefore, optionally, after the filtrate obtained in the step 3) is subjected to flocculation and precipitation treatment, organic matters in the filtrate are recovered, and the filtrate is returned to the step 2) to be used as a water source to adjust the solid content of the primary separation waste; mixing the organic matters in the recovered filtrate with the perishable organic matters separated in the step 3) for aerobic fermentation treatment.

Since the filtrate separated in the above step 3) contains dissolved heavy metals, it is necessary to control the content of heavy metals in the filtrate if the filtrate needs to be recycled to the step 2) as a water source for reuse. Specifically, the content of the heavy metal in the filtrate which is used as the water source in the step 2) is controlled to be lower than 80% of the content of the heavy metal required by the national standard NY 525-2012. The specific total arsenic (As) is less than 10ppm, the total mercury (Hg) is less than 1.5ppm, the total lead (Pb) is less than 30ppm, the total cadmium (Cd) is less than 2ppm, and the total chromium (Cr) is less than 100 ppm. Further, the method for controlling the content of the heavy metal in the reflux filtrate is to detect the content of the heavy metal in the reflux filtrate, if the content of the heavy metal in the filtrate is higher than the requirement on the content of the heavy metal in the filtrate, discharge part of the filtrate as required, and supplement clean water to control the content of the heavy metal in the filtrate. In addition, the amount of the filtrate to be discharged needs to be controlled according to the amount of the total amount of the filtrate generated by the system and the amount of the liquid to be circulated, so as to avoid causing an excessive load on the system.

Further preferably, the filtrate returned to step 2) as the source of water is subjected to deodorization treatment.

Optionally, the solid content of the primarily separated garbage is adjusted to 5% -10% in the step 2).

Optionally, the step 1) of crushing and sorting the garbage to be treated includes the following steps: firstly, shredding garbage to be treated to realize full-scale bag breaking, screening to obtain garbage materials below 200mm, and separating out large garbage materials; and then selectively crushing the garbage materials with the size of less than 200mm, only crushing perishable organic matters and brittle inorganic matters, not crushing soft plastics, fabrics, rubber and high-strength metals, and simultaneously obtaining the garbage materials with the size of less than 20mm through screening separation, namely primary separation garbage. The 200mm garbage materials separated after pretreatment can adapt to crushing and separating treatment, the burden of crushing and separating is reduced, the efficiency is improved, the homogenization of material particles is realized, and the improvement of the flotation effect makes contribution to ensuring the stable quality of the fermented materials.

Optionally, in the step 3), when the slurry containing the perishable organic matters obtained in the step 2) is subjected to filter pressing treatment, the moisture content of the perishable organic matters obtained by separation is controlled to be 60-80%.

Optionally, the aerobic fermentation treatment in the step 3) is closed dynamic aerobic fermentation, and the fermentation time is 3-4 days. The closed dynamic aerobic fermentation is that fermentation equipment provided with a feed inlet, an air inlet and an air outlet is adopted, an exhaust fan is arranged at the air outlet, the air outlet controls a part of exhausted damp-hot gas to return to the air inlet through a valve, the functions of heating and inoculating microorganisms to materials are achieved, and the fermentation process is accelerated; the other part is discharged after deodorization; on one hand, the field environment is controlled in the dynamic aerobic fermentation process, so that the aim of clean production is fulfilled; on the other hand, the material is ensured to be in an aerobic environment under the condition of not adding auxiliary materials through the continuous rotation (1-5 times per hour) of the equipment. The fermentation process of the organic matters under the action of oxygen is a heat release process, the fermentation heat promotes the temperature of the materials to 60-80 ℃, and the moisture in the reactor is continuously discharged under the action of an exhaust fan, so that the aim of drying the materials is fulfilled.

Optionally, the large garbage, the plastic, the fabric and the rubber which are not easy to break and separated in the step 1) and the upper floating material removed in the step 2) can directly enter an RDF energy conversion system for resource recycling; the lower-layer settled material removed in the step 2) can be directly buried or used as a raw material for building material production.

The invention relates to a systematic process method for preparing fertilizer by fermenting perishable garbage, which comprises the steps of firstly crushing and sorting the garbage to be treated, then adding water to adjust the solid content of the garbage to be treated to prepare slurry, and introducing micron bubbles into the slurry. The wet garbage has high water content, especially high cell water content, can not be removed by common dewatering equipment, and the wet sorting method can not increase the water content of the garbage and the process difficulty of a system. The density difference of the broken perishable organic matters, sand, fine plastics and fabrics with relatively uniform grain sizes is large, and the broken perishable organic matters, sand, fine plastics and fabrics are respectively in a suspension state, a sinking state and a floating state in an aqueous medium. According to the hydrophobic characteristics of the surfaces of the bulk materials and the fabric, the three materials are separated quickly and efficiently by means of the flotation principle of micron bubbles. The method can eliminate the refractory organic matters such as plastics and fabrics in the garbage and the non-refractory inorganic matters such as glass, ceramics, sand, metal and the like to the maximum extent. Can stably and effectively reduce and control the content of heavy metals in the refuse derived fertilizer, and is a convenient door for opening the way of the refuse derived fertilizer. And the settled and separated mud and sand materials with high specific gravity have low organic matter and moisture content, meet the requirement of direct landfill and can also be used as raw materials of building materials.

The perishable garbage fertilizer production is an effective organic matter natural circulation rule proved in thousands of years, along with the application of chemical synthetic materials and the development of modern industry, the mixing property of garbage and the long period of traditional compost are main reasons causing the heavy metal content in the garbage derived fertilizer to be higher and uncertain, and the application of the garbage derived fertilizer is hindered. According to the characteristics of kitchen waste, fruit waste and vegetable waste, the invention takes the guarantee of the quality of the final product as a starting point and the premise of reducing the secondary pollution emission to the maximum extent, takes quick and efficient pretreatment as a support, and timely selects and rejects synthetic materials such as plastics and fabrics and inorganic substances such as metals and gravels after the waste is collected, so that the source of harmful elements is firstly reduced to the maximum extent, and the content of the harmful elements in the waste derived fertilizer is finally controlled by using a method for controlling the concentration of heavy metals in the flotation solution, so that the waste derived fertilizer reaches the standard of agricultural fertilizers, and the use limit of the waste fertilizer is thoroughly broken. Solves the problems of the disposal method of the Chinese wet garbage, the destination limitation of the product and the like. Is suitable for treating kitchen garbage, vegetable market garbage, fruit market garbage, livestock and poultry feces, livestock and poultry died of illness and other wastes with high content of perishable organic matters singly or cooperatively.

Detailed Description

The technical solution of the present invention will be described in detail by specific examples.

The household garbage treated by the following embodiment comprises organic perishable garbage such as kitchen garbage, fruit and vegetable and other professional market wastes.

In the following embodiment, step 2) is performed to the primary separated garbage material for the second time, slurry with the adjusted solid content can be added into the flotation tank, the lower part of the flotation tank is provided with a micron bubble generator, the middle part of the flotation tank is provided with a liquid discharge port, the bottom of the flotation tank is provided with a sand discharging mechanism, the material with light specific gravity floats on the upper part of the flotation tank and can be scraped by a scraping mechanism, and the settled sand material on the lower layer can be discharged from a sand discharge port arranged at the bottom of the flotation tank through a screw feeding mechanism.

In the following embodiment, the aerobic fermentation treatment in step 3) is closed dynamic aerobic fermentation, and the fermentation time is 3-4 days. The closed dynamic aerobic fermentation is characterized in that a fermentation tank provided with a feed inlet, an air inlet and an air outlet is adopted, an exhaust fan is arranged at the air outlet, the air outlet controls a part of exhausted damp-hot gas to return to the air inlet through a valve, the functions of heating and inoculating microorganisms to materials are achieved, and the fermentation process is accelerated; and discharging a part of deodorized waste water.