A method for treating semi-coke wastewater and dregs of medicine in cooperation

Abstract

This invention discloses a method for the co-treatment of semi-coke wastewater and medicinal residue, comprising: mixing and soaking the semi-coke wastewater and medicinal residue, and aging the mixture; pressing the aged mixture dry to achieve solid-liquid separation; mixing the separated solids into raw coal for coking; and subjecting the separated liquid to biochemical degradation treatment. This invention solves many problems existing in current semi-coke wastewater treatment methods, opens up broad pathways for the harmless application of medicinal residue, and achieves the effect of treating waste with waste. This invention is an innovative cross-industry collaboration with comprehensive improvements in energy and environmental protection.

Description

Technical Field

[0001] This invention belongs to the fields of energy and environmental protection, and specifically relates to a method for the co-treatment of semi-coke wastewater and pharmaceutical residue. Background Technology

[0002] Semi-coke wastewater, also known as semi-coke wastewater, refers to an industrial wastewater formed during the medium- and low-temperature dry distillation (approximately 600–800℃) of low-rank coal (non-caking coal, weakly caking coal, and long-flame coal) as well as during coal gas purification and semi-coke steam quenching. This wastewater has a complex composition, containing a large number of recalcitrant and highly toxic pollutants, such as benzene compounds, phenols, polycyclic aromatic hydrocarbons, nitrogen oxide heterocyclic compounds, and other organic pollutants, as well as inorganic pollutants such as heavy metals. It is a typical example of highly polluting and highly toxic industrial wastewater.

[0003] The conventional treatment process for semi-coke wastewater includes pretreatment, ammonia stripping, phenol extraction, and then routine biochemical degradation. Each pretreatment step lays the groundwork for subsequent processes, especially the effectiveness of the pretreatment. The main purpose of pretreatment is to remove as much oil and impurities as possible from the semi-coke wastewater to reduce foaming and scaling corrosion during the ammonia stripping process.

[0004] However, due to the presence of surfactants such as creosote in the semi-coke wastewater, the oil in the wastewater is highly emulsified, making it difficult to separate using conventional methods. Simultaneously, the wastewater contains a large amount of dissolved and adsorbed ammonium salts, calcium, magnesium, sodium, and silicon, as well as numerous finely milled organic flocs resembling coal dust. The viscosity is greater than the settling force, and the viscosity increases significantly with decreasing temperature. Therefore, the semi-coke wastewater exhibits complex liquid-phase colloidal characteristics, making it difficult to separate impurities. Furthermore, direct distillation of semi-coke wastewater easily leads to corrosion and scaling; therefore, flocculation and sedimentation are required before distillation, increasing treatment costs. One method of flocculation and sedimentation is using flocculants; however, residual flocculants in the wastewater after flocculation and sedimentation alter the surface activity of the liquid phase, causing foam to wash away impurities. Additionally, the discharged solid phase, containing flocculants, becomes new solid waste. Another method is electrocoagulation, but electrocoagulation consumes a large amount of energy, causes electrode corrosion, and dissolves metal ions, increasing the difficulty of subsequent treatment. In addition, electrocoagulation can cause foreign components to dissolve into the discharged liquid phase, thereby affecting the biochemical degradation of the liquid phase. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a method for the co-treatment of semi-coke wastewater and pharmaceutical residue.

[0006] The technical problem to be solved by this invention is achieved through the following technical solution:

[0007] A method for co-treating semi-coke wastewater and pharmaceutical residue includes:

[0008] The semi-coke wastewater and the medicinal residue were mixed and soaked, and the mixture was then aged.

[0009] The aged mixture is pressed dry to achieve solid-liquid separation;

[0010] The separated solids are mixed into the raw coal for coking;

[0011] The separated liquid is subjected to biochemical degradation treatment.

[0012] Optionally, the residue includes: Chinese medicine residue or Chinese medicine residue mixed with antibiotic bacterial residue.

[0013] Optionally, aging the mixture includes: allowing the mixture to age naturally for ≥15 days.

[0014] Optionally, the method further includes:

[0015] During the aging process of the mixture, steam is introduced into the mixture to heat and stir it.

[0016] Optionally, the step of biochemically degrading the separated liquid includes:

[0017] A portion of the separated liquid is subjected to biochemical degradation treatment, while another portion is returned to the soaking tank to rinse and stir the mixture in the soaking tank.

[0018] Optionally, the method further includes: introducing activated sludge for soaking together with the semi-coke wastewater and the drug residue during the soaking process.

[0019] Optionally, the method further includes treating odorous gases generated during the aging process of the mixture.

[0020] Optionally, the soaking tank is a seepage-proof tank.

[0021] Optionally, the step of pressing the aged mixture to achieve solid-liquid separation includes:

[0022] The aged mixture is pumped out using a sludge pump, and the extracted material is then dried using a vacuum belt or screw press to achieve solid-liquid separation.

[0023] The co-treatment method for semi-coke wastewater and medicinal residue provided by this invention is completely different from the conventional treatment process for semi-coke wastewater. It not only treats the semi-coke wastewater but also opens up broad avenues for the harmless application of medicinal residue, achieving a good effect of treating waste with waste. Specifically, the liquid produced during the treatment process undergoes adsorption and aging to remove biotoxicity, allowing for subsequent biochemical degradation without causing environmental pollution. The solid material produced during the treatment process can be mixed into raw coal for coking, effectively expanding the coal source, and the preferential combustion of plant components in the solid material reduces losses during the coking process. The gases produced by the solid material participating in coking are nitrogen, carbon dioxide, carbon monoxide, and water vapor, without harmful gases. The water adsorbed in the solid material can also improve the water-gas reaction during coking, and the medicinal residue components in the solid material do not contain harmful elements such as lead and mercury, which is beneficial for reducing the total content of harmful elements in the finished coke.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 The image shows elemental comparison data between plants and peat.

[0026] Figure 2 The data on the changes in chemical composition during the coal formation process are shown.

[0027] Figure 3 This is a flowchart of a method for co-treating semi-coke wastewater and pharmaceutical residue provided in an embodiment of the present invention;

[0028] Figure 4 yes Figure 3 A simplified flowchart of the method shown;

[0029] Figure 5 The image exemplifies the elemental composition and calorific value of a set of conventional medicinal residues. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0031] Conventional treatment processes for semi-coke wastewater suffer from numerous problems, including difficulties in separating oil and impurities and the need for flocculants. In attempting to solve this problem, the inventors conducted detailed research on natural coal formation processes and industrial coking processes, discovering that the main component of the medicinal residue—plants—is similar to the composition of peat, lignite, and other coal-forming materials (e.g.,...). Figure 1As shown in the figure, and referring to the natural function of peat filter layers formed by fallen leaves in mountain forests and swamps in intercepting, absorbing, purifying, and separating adhering substances in water, this invention combines the treatment of medicinal residue with the process of peat blending in the coking of raw coal, and invented a method for the co-treatment of semi-coke wastewater and medicinal residue. This method not only solves many problems existing in the treatment methods of semi-coke wastewater in the current technology, but also opens up a broad path for the harmless application of medicinal residue, achieving the effect of treating waste with waste.

[0032] The principle of the co-treatment method for semi-coke wastewater and pharmaceutical residue provided in this embodiment of the invention is explained as follows:

[0033] Coal is formed from ancient plants accumulated in swamps. The formation of coal-bearing basins and the occurrence of coal accumulation are the result of the combined effects of geological factors such as paleontology, paleoclimate, paleogeography, and paleotectonic structures. Some of these have become coal seams with industrial value today.

[0034] See Figure 2 Coal formation is a process in which higher plants continuously grow and die in peat bogs, their remains accumulating and undergoing long-term and complex biochemical, geochemical, physicochemical, and geochemical processes, gradually evolving into peat, lignite, bituminous coal, and anthracite. From an elemental perspective, the coal formation process from plants to coal involves a decrease in hydrogen and oxygen, enrichment and compression of carbon, partial retention of nitrogen, and infiltration and intrusion of sulfur from the strata.

[0035] The entire coal formation process can be divided into two stages: peatification and coalification. Coalification is further divided into two continuous processes: diagenesis and metamorphism. The transformation of peat into lignite is called the diagenetic process, and the transformation of lignite into bituminous coal and anthracite is called the metamorphic process. Coking coal is an oily, soft coal, not ultra-hard anthracite. The coking process is a process in which the soft coal partially burns and dries itself. External heating can reduce internal coking losses, while internal heating can improve heat transfer.

[0036] In this embodiment of the invention, the similarity in composition between medicinal residue and peat produced during the coal formation process is utilized. Referring to the natural function of peat filter layers formed by fallen leaves in forests and swamps in retaining, purifying, and separating adhering substances in water, the medicinal residue is mixed with semi-coke wastewater and soaked. The residue adsorbs the adhering substances in the semi-coke wastewater, thus achieving retention, purification, and separation. Furthermore, since the medicinal residue is similar in composition to peat and lignite, this embodiment of the invention mixes the medicinal residue soaked in semi-coke wastewater into raw coal for coking, which both aids combustion and saves on coking materials.

[0037] The following is a detailed description of the method for co-treating semi-coke wastewater and pharmaceutical residue provided in embodiments of the present invention. See also... Figure 3 As shown, the method includes the following steps:

[0038] S10: Mix the semi-coke wastewater with the medicinal residue and soak it, and then age the mixture.

[0039] It is understandable that the semi-coke wastewater generated during the low-temperature carbonization process of low-rank coal, as well as during coal gas purification and semi-coke steam quenching processes, is high-concentration semi-coke wastewater with a COD ≥ 2 × 10⁻⁶. 5 mg / L. Therefore, step S10 actually involves mixing and soaking high-concentration semi-coke wastewater with pharmaceutical residue. Here, COD represents chemical oxygen demand.

[0040] Among them, the residue includes Chinese medicine residue, or Chinese medicine residue mixed with antibiotic bacterial residue.

[0041] Traditional Chinese medicine residue is the dregs produced during the deep processing of Chinese medicinal herbs. The main components of these herbs are plants, and the extraction process typically uses solvents such as methanol for leaching. This process thoroughly extracts the soluble components. Since solvents are volatile, the recovered residue has already evaporated, making it a very clean absorbent material, similar to a sponge from the source plant. Therefore, it can effectively adsorb substances adhering to semi-coke wastewater, thus playing a role in interception, containment, purification, and leaching separation.

[0042] Antibiotic fermentation residue, the residue discharged during antibiotic production, is already very fine and viscous. Its original nutrients have been strongly absorbed and degraded by pharmaceutical microorganisms, leaving very little residue. However, a large number of residual microorganisms remain, many of which are special species with stronger vitality than those in the natural environment. These microorganisms, mixed with traditional Chinese medicine residue, have a strong effect on the toxic organic substances in semi-coke wastewater. Although some microorganisms are killed by the phenolic toxicity of the semi-coke wastewater, others are absorbed and degraded due to differences in adsorption and permeation concentrations, thus achieving neutralization of toxicity.

[0043] After soaking semi-coke wastewater and medicinal residue, the phenols in the semi-coke wastewater and the polysaccharides in the medicinal residue showed a significant mutual attraction. The starch and fiber components in the medicinal residue also showed a significant mutual attraction with the emulsified tar in the semi-coke wastewater. The fungi in the medicinal residue exhibited a significant adsorption and chelation effect on the mineral components in the semi-coke wastewater. When the medicinal residue was water-saturated, it preferentially adsorbed organic components from the semi-coke wastewater, and the higher the concentration of the semi-coke wastewater, the more pronounced the adsorption.

[0044] After the mixture is soaked and left to stand for a period of time, a lot of loose and flowing soft mud material is formed. The smell of semi-coke wastewater also changes from ammonia and phenol to the smell of actinomycetes and soil, or the special smell of other fungi. This shows that the ancient materials of the coal coking process and the current microbial community are mutually adapted in micromorphology.

[0045] The specific implementation process of step S10 is as follows:

[0046] Pump the semi-coke wastewater into the soaking tank, filling it to approximately 50% of its volume (this is not a limitation); then unload the dregs into the soaking tank, essentially filling it completely, ensuring the dregs are not exposed above the liquid surface. A mixer can also be installed in the tank to ensure the semi-coke wastewater and dregs are mixed evenly.

[0047] Then, the mixture is left to age naturally for several days. The longer it ages, the better the aging effect, similar to the fermentation process of sauce or the natural process of soil formation. Considering time efficiency, it is preferable to let the mixture age naturally for ≥15 days, and the aging time can be appropriately extended in winter. Alternatively, in one implementation, steam can be introduced into the mixture (e.g., steam is introduced into the tank from the bottom) to heat and stir the mixture, which can shorten the aging time. For example, a steam distribution pipe can be buried at the bottom of the soaking tank to use low-pressure steam for stirring and heating, thereby enhancing the adsorption effect.

[0048] Among these, the soaking tank is preferably a seepage-proof pond, which can serve not only as a soaking tank but also as a raw material storage tank, allowing for the large-scale reception and storage of medicinal residue. Of course, if the cost is sufficient, the semi-coke wastewater and medicinal residue can also be soaked in a separate soaking tank.

[0049] For example, a seepage-proof pool can be constructed using reinforced concrete. The size of the pool can be, for example, 20m × 10m × 5m. The pool walls are sloped to counteract the lateral pressure of the soil. The bottom and surface of the pool are sealed with epoxy resin to prevent seepage corrosion. The bottom of the pool can be designed to slope towards the outlet end to facilitate subsequent pumping. The upper edge of the pool is at least 20cm above the ground.

[0050] In practical applications, multiple soaking tanks can be set up so that they can be used alternately, improving the efficiency of the soaking process. Additionally, during the soaking process, rainwater should be prevented from entering the tanks as much as possible.

[0051] S20: The aged mixture is squeezed dry to achieve solid-liquid separation.

[0052] Specifically, the aged mixture is pumped out using a sludge pump, and the extracted material is then dried using a vacuum belt or screw press to achieve solid-liquid separation.

[0053] In practice, screw presses are more efficient at squeezing and save more installation space. In contrast, the filter layer of a vacuum belt press is easily clogged by a layer of sticky, fine mud, resulting in vacuum failure, wasted energy, and inferior squeezing performance compared to screw presses.

[0054] S30: The separated solid material is mixed into the raw coal for coking.

[0055] Specifically, the separated solids are uniformly mixed into the raw coal in a specific ratio before entering the coking process. Once in the coking furnace, the solids, due to their more fragile chemical composition compared to the raw coal, are preferentially decomposed by heat. Organic impurities adsorbed by the residue are preferentially degraded, and ammonia in the residue is oxidized into harmless nitrogen gas, while other elements are converted into carbon dioxide, carbon monoxide, and water vapor, thus preventing environmental pollution. Furthermore, the moisture adsorbed by the residue can improve the water-gas reaction, and the preferential combustion of plant components reduces raw coal loss during coking. In addition, unlike raw coal, the residue does not contain harmful elements such as lead and mercury. Therefore, mixing it into the raw coal for coking is beneficial in reducing the total content of harmful elements in the finished coke, neutralizing the environmental impact of ancient biomass (raw coal).

[0056] Figure 5 The example illustrates the elemental composition and calorific value of a set of conventional medicinal residues. It can be seen that the main elements include carbon, hydrogen, oxygen, nitrogen, and sulfur. Sulfur is a protein component and can be bio-absorbed and degraded during the soaking process or subsequent biochemical degradation treatment.

[0057] In addition, mixing the separated solids into the raw coal for coking is equivalent to supplementing the coal source, thus reducing coking losses and improving the quality of finished coke, which has a comprehensive positive effect.

[0058] In this embodiment of the invention, the solid material separated in step S20 can be directly mixed into the raw coal for coking without additional drying treatment. That is, drying the solid material before mixing it into the raw coal for coking is not necessary, but this does not preclude the possibility of introducing a drying process in specific circumstances (e.g., when the pressing effect of the press is very unsatisfactory).

[0059] S40: The separated liquid is subjected to biochemical degradation treatment.

[0060] Specifically, after mixing and soaking the medicinal residue with the semi-coke wastewater, the wastewater underwent detoxification and nutrient replenishment, resulting in a significant increase in the B / C ratio of the separated liquid, rising from less than 0.1 to over 0.4, indicating a marked improvement in biodegradability. The B / C ratio is an abbreviation for the ratio of BOD (Biochemical Oxygen Demand) to COD, which represents the biodegradability of the wastewater. Biological experiments confirmed that the COD of the untreated semi-coke wastewater was 5 × 10⁻⁶. 4 ~2×10 5 mg / L, BOD between 4200 and 5500 mg / L; COD of the liquid separated after soaking is 3.6 × 10 mg / L. 4 ~5.5×10 4 mg / L, BOD at 2.8×10 4 ~4.5×10 4Therefore, the concentration of mg / L indicates that the liquid separated after soaking is adaptable to biochemical degradation and can be directly discharged into the biodegradation buffer tank for continuous use.

[0061] The co-treatment method for semi-coke wastewater and medicinal residue provided in this invention is completely different from conventional semi-coke wastewater treatment processes. It not only treats the semi-coke wastewater but also opens up broad pathways for the harmless application of medicinal residue, achieving a good effect of treating waste with waste. Specifically, the liquid produced during the treatment process undergoes adsorption and aging to remove biotoxicity, allowing for subsequent biochemical degradation without causing environmental pollution. The solid material produced during the treatment process is mixed with raw coal for coking, effectively expanding the coal source, and the preferential combustion of plant components in the solid material reduces losses during coking. The gases produced during the coking process from the solid material are nitrogen, carbon dioxide, carbon monoxide, and water vapor, without harmful gases. The adsorbed water in the solid material improves the water-gas reaction during coking, and the medicinal residue components in the solid material do not contain harmful elements such as lead and mercury, which is beneficial for reducing the total content of harmful elements in the finished coke.

[0062] It is worth mentioning that the utilization rate of medicinal materials during the deep processing of traditional Chinese medicine is low, resulting in a large amount of dregs that are difficult to handle. Specifically, landfill disposal requires land and is costly; incineration requires additional drying of the dregs due to their high water content, further increasing costs; composting the dregs can easily lead to microbial contamination of farmland and has been restricted; a small portion of the dregs can be used as feed or for cultivating edible fungi after being crushed, but the consumption rate is far behind the rate of dregs production, and improper use can also affect food safety; managing the dregs as hazardous waste is limited in terms of channels and incurs high fees. Furthermore, antibiotic residues have the characteristic of microbial diffusion, which also impacts the microbial ecosystem of the natural environment. Therefore, this invention co-treats semi-coke wastewater and dregs, not only solving many problems existing in the current semi-coke wastewater treatment methods, but also opening up broad avenues for the harmless application of dregs. This is an innovative cross-industry collaboration, and more importantly, this invention achieves multiple beneficial effects using a simple treatment process.

[0063] Optionally, in one implementation, step S40 may specifically include: performing biochemical degradation treatment on a portion of the separated liquid, and returning another portion of the liquid to the soaking tank to rinse the mixture in the stirred soaking tank.

[0064] Understandably, returning a portion of the liquid to the soaking tank can rinse the mixture within the tank, creating a uniform slurry that helps the sludge pump draw it out for the press dryer to feed.

[0065] Optionally, in one implementation, the co-treatment method for semi-coke wastewater and medicinal residue provided in this embodiment of the invention may further include: introducing activated sludge for soaking together with the semi-coke wastewater and medicinal residue during the mixed soaking process.

[0066] It is understandable that activated sludge is produced by a biological system. Introducing activated sludge into the soaking tank to participate in adsorption and aging is equivalent to supplementing the microorganisms in the detoxification process, thereby improving the aging effect.

[0067] Optionally, in one implementation, the co-treatment method for semi-coke wastewater and pharmaceutical residue provided in this embodiment of the invention may further include: treating odorous gases generated during the aging process of the mixture.

[0068] Specifically, during the soaking process, the soaking tank will have the acetaminophen odor of fresh semi-coke wastewater, the sour odor of pharmaceutical residue, and odors that have changed after aging. Therefore, in order to improve on-site working conditions, an exhaust system can be used to draw away the odorous gases and send them to ozone catalytic purification or to the coking furnace intake air system for incineration purification.

[0069] In summary, the co-treatment method for semi-coke wastewater and medicinal residue provided in this embodiment of the invention solves many problems existing in the prior art for semi-coke wastewater treatment methods, opens up a broad path for the harmless application of medicinal residue, and the treatment result does not put pressure on the environment or cause environmental pollution, thus having comprehensive improvement significance in terms of energy and environmental protection.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0071] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings and the disclosure, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the description of this invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0072] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for co-treating semi-coke wastewater and pharmaceutical residue, characterized in that, include: The semi-coke wastewater and the drug residue were mixed and soaked, and the mixture was then aged. The aged mixture is pressed dry to achieve solid-liquid separation; The separated solids are mixed into the raw coal for coking; The separated liquid is subjected to biochemical degradation treatment.

2. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, The dregs include: Chinese medicine dregs or Chinese medicine dregs mixed with antibiotic bacterial residue.

3. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, The aging of the mixture includes: letting the mixture age naturally for ≥15 days.

4. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, Also includes: During the aging process of the mixture, steam is introduced into the mixture to heat and stir it.

5. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, The process of biochemically degrading the separated liquid includes: A portion of the separated liquid is subjected to biochemical degradation treatment, while another portion is returned to the soaking tank to rinse and stir the mixture in the soaking tank.

6. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, Also includes: When mixing and soaking semi-coke wastewater and pharmaceutical residue, activated sludge is introduced for soaking together.

7. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, Also includes: Treat the odorous gases generated during the aging process of the mixture.

8. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 5, characterized in that, The soaking pool is a seepage-proof pool.

9. The method for co-treating semi-coke wastewater and pharmaceutical residue according to claim 1, characterized in that, The process of pressing the aged mixture to achieve solid-liquid separation includes: The aged mixture is pumped out using a sludge pump, and the extracted material is then dried using a vacuum belt or screw press to achieve solid-liquid separation.

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