WO2021040499A1 - Ammonium removal apparatus and method using chemical treatment of wastewater generated by dehydrating digested sludge - Google Patents

Abstract

Disclosed are: an ammonium removal method for removing ammonium, by means of a chemical treatment process, from a dehydrated filtrate of digested sludge discharged from an anaerobic digestion facility, which treats organic waste so as to convert same into sludge (microorganisms); and an apparatus to be used in the method, the method comprising: a) a first step of converting a bicarbonate (HCO₃ ^-) in the dehydrated filtrate into carbonic acid (H₂CO₃) and removing same; b) a second step of converting an ammonium ion (NH₄ ⁺) in the dehydrated filtrate, having passed through the first step, into gaseous ammonia (NH₃) and discharging same; and c) a third step of neutralizing the dehydrated filtrate having passed through the second step. When using chemical treatment comprising acidification, alkalinization and neutralization, high chemical treatment efficiency, that is, ammonium removal efficiency, can be implemented while optimizing the amount of chemicals to be consumed, and the efficiency of biological treatment of wastewater in the latter part thereof can also be greatly enhanced.

Description

Apparatus and method for removing ammonium through chemical treatment of wastewater dehydrated from digested sludge

The present invention relates to an apparatus and method for treating dehydrated wastewater (dewatered filtrate) from digested sludge discharged from an anaerobic digestion facility for high-concentration organic wastewater such as food waste, drinking water, and manure, or waste (hereinafter,'organic waste'). And in particular to an apparatus and method for removing ammonium from said wastewater.

In general, anaerobic digestion of organic matter containing a high concentration of nitrogen can be explained by the following formula (1). Based on the total molecular weight of organic matter containing moisture (MW 285.4), 70% is _{converted into biogas (CH 4} ,CO ₂ ) by anaerobic microorganisms (methanogenic bacteria), and 8% of the total molecular weight is converted into microorganisms in this process. It grows, and only 2.8% of pure organic matter is used for microbial growth. 17% bicarbonate ions (bicarbonate, HCO ₃ ^-) are converted into the digester buffering capacity (buffer capacity) measure of bicarbonate alkalinity contributes to (bicarbonate alkalinity), was produced in the hydrolysis process, the nitrogen could be used to multiply the total molecular weight of the It accumulates in the digester in the form of a concentration _{of NH 4} ⁺ -N as 5%.

Formula (1) can be described as follows. As organic matter (C ₁₀ H ₁₉ O ₃ N) is decomposed by microorganisms, 0.2M microorganisms (C ₅ H ₇ O ₂ N) proliferate, and nitrogen (NH ₄ ⁺ ) is involved in the proliferation of cells in this process. . Finally organic matter that decomposes longer decomposition inorganic form of bicarbonate (bicarbonate, HCO ₃ ^-) in the water to be left as, nitrogen could not be used for microbiological synthesis include ammonium ^{_{(NH 4 +) (NH 4}} HCO 3) form Remains. The reason why nitrogen (N) was not synthesized in microorganisms is because organic matters necessary for the growth of microorganisms are insufficient, because the concentration of organic matters is low compared to the concentration of nitrogen (N). This is expressed as a low C/N ratio. This expression comes from an excessive amount of nitrogen compared to the appropriate amount of organic matter. In the process of decomposition of organic matter, biogas is produced as a by-product, and 5.74M of methane (CH ₄ ) and 2.45M of carbon dioxide (CO ₂ ) are produced. And organic materials as shown in the formula (1) bicarbonate (bicarbonate, HCO ₃ ^-) in the final step is to create there is markedly alkalinity (alkalinity), is known as the bicarbonate alkalinity (bicarbonate alkalinity). The optimum condition for this bicarbonate alkalinity in an anaerobic digester _{is known to be in the range of 1,000 to 5,000 mg/L as CaCO 3} , and in the case of anaerobic digestion of high concentration organic waste such as food waste, the bicarbonate alkalinity is 15,000 to 15,000. when the range of 25,000mg / L as CaCO _3. This is because alkalinity depends on the amount of organic matter, as shown in this equation. The range of alkalinity is different from that of sewage sludge due to the difference in the concentration of organic matter. In the case of the United States, food is changed to a disposer and then flowed into the sewage, so there is a difference in the design standard of a sewage treatment plant from that of Korea, but it can be said that it is almost the same except for this.

In general, when the bicarbonate is present in an appropriate amount, it plays a beneficial role in mitigating the impact of the pH change in the digester due to overload of organic matter, but the bicarbonate HCO ₃ ^- generated by continuous decomposition of organic matter is used in the digester. If it accumulates excessively in the anaerobic digestion process itself, the efficiency of treating wastewater at the rear stage may be lowered. That is, according to the International Study of ammonium produced in the anaerobic digestion process of organic matter (NH ₄ ⁺⁾ and bicarbonate (bicarbonate, HCO ₃ ^-) is the report that is strongly bound in the form of ammonium bicarbonate (NH ₄ HCO ₃₎ bar. In this case bicarbonate (bicarbonate, HCO ₃ ^-) are Although not the role is clearly been shown the combination is at the same time as a buffer action due to inhibition to interfere with the increase of pH to 10.5 ~ 11.0, but rather to increase the pH in the waste water treatment purposes If necessary, it is difficult to increase the pH to the required pH even when a chemical is used, so it can be considered that there is a problem that the treatment efficiency for wastewater is lowered.

_{Specifically, the process of removing ammonium (NH 4} ⁺ ) from wastewater, that is, the dehydration liquid of digested sludge, is carried out by chemically treating it with chemicals while increasing the pH and discharging it as _{gaseous ammonia (NH 3 ).} If the bicarbonate alkalinity is excessive, it is difficult to increase the pH by caustic soda (NaOH), so the treatment efficiency decreases, and the amount of chemicals used increases exponentially as the pH increases. In addition, in the aerobic biological treatment of wastewater having high organic matter and alkalinity in the downstream, excessive air is supplied, and in the process, the temperature of the bioreactor rises to 40°C or more, thereby lowering the oxygen transfer power. As a result, microorganisms lose their function at high temperatures and decrease their sedimentation properties, ultimately deteriorating dehydration properties as well as poor treatment results, and further forcibly lowering the increased temperature of the bioreactor. It is clear that economic feasibility deteriorates.

Therefore, in relation to the treatment of the dewatered filtrate of digested sludge discharged through the anaerobic digestion process, ammonium through chemical treatment {(ammonia nitrogen, NH ₃ -N) where, NH ₃ -N = [NH ₄ ⁺ -N] + [NH ₃ ]} In order to improve the removal efficiency, the removal (conversion to another substance) of bicarbonate, which interferes with the chemical reaction, needs to be preceded. In this case, not only the ammonium removal efficiency through chemical treatment but also the It can be expected to be advantageous also in biological treatment efficiency, and the present invention was made on the basis of this background.

The present invention was devised in consideration of the limitations of nitrogen concentration treatment in the wastewater treatment process at the rear end of the anaerobic digestion facility for conventional high-concentration organic waste, and provides an apparatus and method with improved efficiency in removing ammonium through chemical treatment. .

The subject matter of the present invention related to the above problem is the same as described in the claims below.

(1) A method of removing ammonium from the dewatered sludge discharged from an anaerobic digestion facility that treats organic waste and converts it into sludge (microorganism) by chemical treatment, a) bicarbonate (HCO) in the dewatered filtrate. ^₃₎ a first stage to remove converted to carbon dioxide _{(carbonic acid, H 2 CO 3} ); b) a second step of converting and discharging ionic ammonium (NH ₄ ⁺ ) into gaseous ammonia (NH _{3) in the dehydration liquid passed through the first step;} And c) a third step of neutralizing the dehydration liquid passed through the second step.

(2) In the step (a), the dehydration solution is adjusted to pH 4.0 by adding an acidifying agent selected from _{sulfuric acid (H 2} SO _{4) and hydrochloric acid (HCl).} .

(3) In the step (b), the dehydration solution is adjusted to pH 10.5 to 11.0 by adding an alkali chemical selected from sodium hydroxide (NaOH), calcium hydroxide (Ca(OH) _{2) and slaked lime (CaO),} The ammonium removal method of (1), characterized in that it is carried out by injecting air.

(4) In the step (c), the dehydration solution is adjusted to pH 8 to 9 by adding a neutralizing agent selected from _{sulfuric acid (H 2} SO _{4) and hydrochloric acid (HCl).} How to remove.

In the treatment of wastewater (dewatered filtrate) dehydrated from digested sludge according to the present invention, a degassing system of a chemical treatment method including acidification, alkalinization and neutralization is applied. If, ammonium bicarbonate (NH ₄ HCO _3), which can destroy the strong coupling of the type to inhibit pH rise bicarbonate (bicarbonate, HCO ₃ ^-) via the acidification process, by removing in advance, an appropriate amount of drug in the alkaline process The pH can be controlled to 10.5 ~ 11.0 just by using, and at this pH state, nitrogen in the form of _{ammonium (NH 4} ⁺ ) is converted _{into ammonia (NH 3) by appropriate agitation and air injection.} High chemical treatment efficiency, that is, ammonium removal efficiency can be achieved. In the case of chemical processing apparatus and method according to the invention, the bicarbonate in the waste water in such a chemical process for ammonium removal (bicarbonate, HCO ₃ ^-) since the concentration of the substantially removed the other for the waste water formed in the rear end biological Treatment efficiency can also be greatly improved, and it can be applied to all facilities that apply anaerobic digestion system including food waste, drinking water, combined treatment of livestock manure and food waste, livestock manure, etc., livestock manure public treatment facilities, manure treatment It can also be applied to processes that treat high-concentration organic wastewater or wastes such as facilities.

1 is a graph showing the relative concentration of ammonia (NH _{3 ) to ammonium (NH 4} ⁺ ) according to changes in pH and temperature.

2 is a graph showing the amount (%) of carbonic acid (H ₂ CO ₃ ) in total carbon dioxide (CO _{2) according to pH change.}

Figure 3 is a graph showing the concentration (mol %) _{of hydrogen sulfide (H 2} S) in the total sulfide according to the pH change.

4 is a gas removal system of a chemical treatment method and a process diagram thereof according to an embodiment of the present invention.

Figure 5 is a structure and operation diagram of the reaction tank for the chemical treatment of Figure 4;

Hereinafter, the present invention will be described in detail through examples. Prior to this, terms or words used in the present specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention. Therefore, the configuration of the embodiments described in the present specification is only one of the most preferred embodiments of the present invention, and does not represent all the technical spirit of the present invention, and various equivalents that can replace them at the time of filing of the present invention It should be understood that there may be variations and variations. On the other hand, in the drawings, the same or similar reference numbers are given to the same or equivalent material, and in the entire specification, when a certain part "includes" a certain component, this is another component unless otherwise stated. It does not exclude, but means that other components may be further included.

As in the present invention, most chemical methods for treating the concentration _{of ammonium (NH 4} ⁺ ) in the wastewater (dewatered filtrate) dehydrated from the digested sludge discharged from the anaerobic digestion facility for high-concentration organic waste This is a method of separating _{ammonium (NH 4} ⁺ ) in the form of ammonia (NH ₃ ) gas in the state that the pH of the wastewater discharged from is usually increased to 10 or more. In this case, dehydrated filtrate of bicarbonate (bicarbonate, HCO ₃ ^-) when the concentration is excessive it is difficult to pH increase due to the nature of the bicarbonate to try to maintain a neutral, using a large amount of drugs to increase the pH to Fig result that the process efficiency good give. The present invention bicarbonate (bicarbonate, HCO ₃ ^-) present in the over-the waste water chemicals involved in the degassing process by performing the after removing in advance through a kind of pre-processing step of oxidation (Acidification) process degassing (degassing) process It is a basic feature of maintaining an appropriate amount of input and at the same time improving its processing efficiency.

In this case, with respect to the chemical treatment that separates _{ammonium (NH 4} ⁺ ) into ammonia (NH ₃ ) gas and its efficiency, the relative concentration between _{ammonium (NH 4} ⁺ ) and ammonia (NH _{3) according to pH and temperature changes.} with understanding of the characteristics relating to the chemical reaction (relative concentration), addition of bicarbonate (bicarbonate, HCO ₃ ^-) is a prerequisite for the understanding of the chemical reaction accompanying removal properties. Hereinafter, after describing the main chemical reaction characteristics accompanying the present invention, a degassing system and an operation example of a chemical treatment method proposed by the present invention will be sequentially described in detail based on these reaction characteristics.

One. Main reaction characteristics considered during chemical treatment (Fig. 1, Fig. 2)

First, FIG. 1 is a graph showing the relative concentration of ammonia (NH _{3 ) to ammonium (NH 4} ⁺ ) according to changes in pH and temperature. As temperature and pH increase, ammonium in an ionic state (NH ₄ ⁺ ) Represents the conversion to volatile gaseous ammonia (NH _{3 (g) ).} In particular, looking at the change in the relative concentration between _{NH 4} ⁺ and NH ₃ depending on the pH _{, as the pH increases, ammonium (NH 4} ⁺ ) decreases and ammonia (NH ₃ ) increases, reaching the vicinity of point (b), which is a pH of about 9.0. In this case, NH ₄ ⁺ and NH ₃ are in equilibrium, so that the concentrations of each are approximately the same at 50% level. The main purpose of the chemical treatment is to separate the _{NH 4} ⁺ as much as possible into the NH _{3 gaseous form.} It is possible to change the form of gas up to 95 ~ 98% at pH 10.5 ~ 11.0 that has passed the ⓒ point of pH 10. Of course, at pH 11.0, almost 100% is _{converted to NH 3} , but since it may be a condition where nutrients are insufficient in the later biological process, 95% treatment can be the most effective method for the subsequent wastewater treatment. On the other hand, since the difference between theory and practice may occur, it can be said that it is reasonable to maintain the proper pH range in the range of 10.5 to 11.0.

From FIG. 1, in this appropriate range of pH 10.5 to 11.0, a high ammonium removal efficiency of 95% or more is theoretically expected, but in practice most chemical treatment facilities have a relatively low removal efficiency (about 50%) at the level of about 60 to 70%. It is known to achieve. The reason is that bicarbonate (bicarbonate, HCO ₃ ^-) in excessive levels is because it is difficult to due to the alkalinity caused by, or bicarbonate increase the pH 9.5 or higher. As a result, the bicarbonate (bicarbonate, HCO ₃ ^-) strip the alkalinity of the waste water if it can be expected to remove the high ammonium removal efficiency.

Meanwhile, FIG. 2 is a graph showing the amount (%) of carbonic acid (H ₂ CO _{3 ) in the total carbon dioxide (CO 2} ) according to the pH change. In the case of wastewater at 35° C. from FIG. 2, the chemical reaction according to the pH change is shown in the following formula ( It can be expressed as 2). 2 and Formula (2), bicarbonate (HCO ₃ ^- ) is the most ideal and effective in a state where wastewater is placed at the corresponding pH because _{most of the bicarbonate (HCO 3-) exists as H 2} CO ₃ at the point ⓐ at pH 4. It can be seen that it can be removed.

2. Chemical treatment method degassing system and process chart (Fig. 4)

The degassing system of the chemical treatment method according to the present invention (Fig. 4B) is related to treatment of wastewater (dewatered filtrate) dehydrated from digested sludge, and in particular, acidification, alkalinization and Performs the main unit process of neutralization. 4 shows a gas removal system of a chemical treatment method and a process diagram thereof according to an embodiment of the present invention.

[STEP I] Acidification-Carbonic acid generation step

This Step is Ⅰ bicarbonate (bicarbonate, HCO ₃ ^-) of the dehydration filtrate (the waste water) is a step of removing converted to carbon dioxide _{(carbonic acid, H 2 CO 3} ). When a drug for acidification (acidification) in dehydrated filtrate (waste water) separated from the digested sludge, for example, input of sulfuric acid (H ₂ SO _4), bicarbonate was combined with ammonium ^{_{(NH 4 +) (bicarbonate,}} HCO 3 -) Is separated and converted into carbonic acid (H ₂ CO ₃ ) by bonding with hydrogen ions (H ⁺ _{) released from H 2} SO ₄ , and thus ammonium (NH ₄ ⁺ ) and sulfate (SO ₄ ^2- ) are It is put in a decomposed state according to formula (3) of In this case, as can be seen in FIG. 2, at pH 4.0, all bicarbonate is _{converted into carbonic acid (H 2} CO ₃ ) and removed. As a chemical for the acidification, it may be substituted with various acidic chemicals including hydrochloric acid (HCl) in addition _{to the exemplified sulfuric acid (H 2} SO _{4 ).}

[STEP II] Alkalinization-Degassing step

In this Step Ⅱ, ionic ammonium (NH ₄ ⁺ ) in dehydration (wastewater) is converted into gaseous ammonia (NH ₃ ) and discharged. Specifically, by adding sodium hydroxide (NaOH) as a chemical for alkalinization to the dehydration (wastewater) passed through Step I and adjusting the pH in the range of 10.5 to 11.0, ammonia for _{ammonium (NH 4} ⁺⁾ The relative concentration of (NH ₃ ) is placed in an increased state, and by injecting air in this state, gaseous ammonia (NH ₃ ) is discharged to the outside according to formula (4) below. In this case, prior bicarbonate (bicarbonate, HCO ₃ ^-) in Step 1 may be the pH is quickly guided to the high state while keeping the proper that amount because the input of sodium hydroxide (NaOH) in a pre-removed, before even As can be seen in 1, a high ammonium removal efficiency of 95% or more can be achieved in a high pH state of pH 10.5 to 11.0. _{As the alkalizing agent, various good products including calcium hydroxide (Ca(OH) 2} ) and slaked lime (CaO) in addition to the exemplified sodium hydroxide (NaOH) may be used instead.

Meanwhile, according to Formula (4), in _{addition to gaseous ammonia (NH 3} ), various exhaust gases such as hydrogen sulfide (H ₂ S), oxygen (O ₂ ) and carbon dioxide (CO ₂ ) are accompanied, and ammonia among these exhaust gases In addition to (NH ₃ ), hydrogen sulfide (H ₂ S) can be synthesized in the form of ammonium hydrogen sulfide ((NH ₄ ) ₂ SO _{4 ), which is a raw material component of fertilizer. In addition, since 98 to 100% of total sulfur (sulfide) in the exhaust gas is present as H 2} S in the range of pH 10.5 to 11.0, as can be seen in FIG. 3, there is also a problem of odor in wastewater when treating exhaust gases. Can be solved.

[STEP III] Neutralization-Neutralization step

This Step Ⅲ is a step of neutralizing the alkaline wastewater filtrate (wastewater) in the range of pH 10.5 to 11.0 that has passed through Step Ⅱ for later biological treatment. As a neutralizing agent, for example, sulfuric acid (H ₂ SO ₄ ) may be used, and the wastewater is adjusted to a neutral pH (pH 8-9). This is a neutralization reaction by the introduction of sulfuric acid (H ₂ SO ₄ ) and is represented by the following formula (5). Likewise, as a chemical for neutralization, various chemicals including hydrochloric acid (HCl) in addition _{to the exemplified sulfuric acid (H 2} SO _{4) may be used instead.}

As described above, if all three steps of acidification, alkalinization, and neutralization are performed on the digested sludge dewatered liquid (wastewater) by applying the degassing system of the chemical treatment method of FIG. 4 In addition, by removing an excessive amount of bicarbonate, the chemical treatment efficiency of ammonium (ammonia nitrogen) can be improved, and when these interfering substances are removed, the efficiency in a later biological treatment process can be improved.

3. Examples of operation of a degassing system of a chemical treatment method (FIGS. 4 and 5)

Based on FIGS. 4 and 5, the processing process of the gas removal system of the chemical treatment method according to the embodiment of the present invention will be described in more detail. 5 shows a schematic structural diagram of a reaction tank for chemical treatment of FIG. 4.

a) In order to operate the gas removal system (B), solid matter removal is preceded, and after being transferred to the equalizing tank (A), the operation of the gas removal system (B) is started. The wastewater carried in and stored in the equalization tank (A) is pumped to the degassing system (B) for chemical treatment.

b) The mechanical configuration of the reaction tank for performing the unit process of the gas removal system B is shown in FIG. 5, and functions of main parts of the drawing are as follows. The reaction tank (Degassing Reactor) consists of four baffles (01), a motor and a stirrer (02) in each 90° direction for complete mixing and efficient chemical reaction, and the air supply system (05), the gas after the reaction It can be carried out through the gas discharge pipe 11 and sent to the exhaust gas treatment process 12 at a later stage for the manufacture of liquid fertilizers and the like. For the stepwise chemical reaction of the gas removal system (B), an acid storage tank (03) and an alkali storage tank (04) are required, and here, a chemical used to control the chemical reaction according to pH control. In the case of acid, sulfuric acid (H ₂ SO ₄ ) and hydrochloric acid (HCl), in the case of alkali, caustic soda (NaOH), calcium hydroxide (Ca(OH) ₂ ) and slaked lime (CaO) may be used. The boiler 06 is used to control the temperature of the wastewater in order to prevent the temperature drop, which is concerned during the chemical reaction process, through air supply. A wastewater discharge pipe (09), and a pressure control device (08), etc. are provided so that the pressure inside the reaction tank (degassing reactor) does not drop sharply when the wastewater is discharged.

c) The gas removal system (B) should be installed in an open space where there is a lot of ventilation, and should be inspected daily, avoiding the installation of closed rooms.

d) the reactor (degassing reactor) provided in the gas removal system (B) is composed of a single or bicarbonate present in the waste water (bicarbonate, HCO ₃ ^- In order to a) and ammonium (NH ₄ ^+), chemically continuous process in a two- Two or more reaction tanks (a, b) can be configured in parallel, or evenly distributed (50% of each of the two reaction tanks) and processed separately. Each of the plurality of degassing reactors independently performs three steps of acidification, alkalinization and neutralization shown in FIG. 4.

e) first in accordance with the Step I of Figure 4 and 5 the ammonium (NH ₄ ⁺⁾ and bicarbonate ion is strongly bonded (bicarbonate ion, HCO ₃ ^-) until reaching a pH4 from acid storage tank (03) to remove the When the sulfuric acid (H ₂ SO ₄₎ is turned on, bicarbonates (bicarbonate, HCO ₃ ^-) are removed as converted to acid (H ₂ CO _3).

f) Next, sodium hydroxide (NaOH) is added from the alkali storage tank 04 until the pH reaches 10.5 to 11.0 according to Step II of FIGS. 4 and 5. In this process, when air is supplied through the air supply system (05), ionic ammonium (NH ₄ ⁺ ) is converted into gaseous ammonia (NH ₃ ), and other exhaust gases such _{as H 2} S, O ₂ and CO ₂ And moisture (H ₂ O) is discharged together. In this case, a motor and agitation facility (02) should be installed for pH control as a whole, and an air supply system (05) should be provided so that degassing can be performed well, and a boiler ( 06) is installed to enable automatic temperature control. In the degassing step of Step Ⅱ, the operation is optimized by deriving an optimum reaction time and an appropriate amount of acid and alkali so _{that an appropriate amount of ammonium (NH 4} ^{+) can be removed.}

_{g) Finally, in the neutralization step of Step ² of FIGS. 4 and 5, sulfuric acid (H 2} SO ₄ ) from the acid storage tank (03) until it reaches a pH of 8 to 9 near the neutral of the wastewater for biological treatment. Is put into it.

h) Referring to FIG. 4, when all the steps of Step I to Step ² described above by the gas removal system B are completed and become neutral, the suspended state is improved and fine solids begin to be seen again. These can be fed to the polymer flocculant (07), concentrated in the pressure flotation system (C), and transferred to the dehydrator (10). After the dehydration process, the entire chemical treatment process including the gas removal system B is completed by being transferred to the equalizing tank D for biological treatment.

In the treatment of wastewater (dewatered filtrate) dehydrated from digested sludge according to the present invention as described above, a degassing system of a chemical treatment method including acidification, alkalinization and neutralization when applied to, ammonium bicarbonate (NH ₄ ⁺⁾ and bicarbonate (HCO ₃ ^-) via the acidification process of bicarbonate (bicarbonate, HCO ₃ ^-) to inhibit the destruction of the pH rise to strong binding of the is removed in advance. In the alkalizing process, a pH of 10.5 to 11.0 may be controlled by using an appropriate amount of a chemical. When nitrogen is removed by injecting air in this pH state _{and discharging it as ammonia (NH 3} ), a high chemical treatment efficiency of 95% or more, that is, ammonium removal efficiency can be realized. In the case of chemical processing apparatus and method according to the invention, this chemical treatment bicarbonate (bicarbonate, HCO ₃ ^-) in the waste water in the process for ammonium removal, because the concentration of the most Removed another for waste water formed in the rear end biological Treatment efficiency can also be greatly improved, and it can be applied to all facilities that apply anaerobic digestion systems including food waste, drinking water, combined treatment of livestock manure and drinking water, livestock manure, etc., livestock manure public treatment facilities, manure treatment It can also be applied to processes that treat high-concentration organic wastewater or wastes such as facilities.

The above description relates to specific embodiments of the present invention. As described above, the above embodiments according to the present invention are disclosed for purposes of explanation and are not understood to limit the scope of the present invention, and those of ordinary skill in the art will not depart from the essence of the present invention. No, it should be understood that various changes and modifications are possible. Accordingly, all such modifications and changes can be understood as falling within the scope of the invention disclosed in the claims or their equivalents.

Claims (4)

1. The dehydrated filtrate of the digested sludge discharged from the anaerobic digestion facility to switch to the sludge by treating the organic waste as a method of removing ammonium by a chemical process, a) bicarbonates (bicarbonate, HCO ₃ of the dehydration filtrate ^- a) acid ( carbonic acid, H ₂ CO ₃ ) The first step of removing the conversion; b) a second step of converting and discharging ionic ammonium (NH ₄ ⁺ ) into gaseous ammonia (NH _{3) in the dehydration liquid passed through the first step;} And c) a third step of neutralizing the dehydration liquid passed through the second step.
2. The method of claim 1, wherein in step (a), the dehydration solution is adjusted to pH 4.0 by adding an acidifying agent selected from _{sulfuric acid (H 2} SO _{4) and hydrochloric acid (HCl).}
3. The method of claim 1, wherein the step (b) comprises adding an alkali chemical selected from sodium hydroxide (NaOH), calcium hydroxide (Ca(OH) ₂ ) and slaked lime (CaO) to adjust the dehydration solution to a pH of 10.5 to 11.0. In the state, ammonium removal method, characterized in that carried out by injecting air.
4. The method of claim 1, wherein in step (c), _{a neutralizing agent selected from sulfuric acid (H 2} SO ₄ ) and hydrochloric acid (HCl) is added to adjust the dehydration filtrate to pH 8-9. .

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