KR101099869B1 - Method and apparatus for treating anaerobic digestive fluid - Google Patents

Abstract

The present invention relates to an anaerobic digestion liquid treatment apparatus and method capable of effectively removing high concentrations of organic nitrogen, nitrogen, and phosphorus contained in the anaerobic digestion liquid of a high concentration organic waste. In the anaerobic digestion liquid treatment apparatus for treating an anaerobic digestion liquid, the intermittent aeration tank and the membrane separation device is a combination, wherein the intermittent aeration tank is subjected to the aeration process and the non-aeration process in a time series to repeat the conditions in the intermittent aeration tank By removing the organic components, nitrogen, and phosphorus in the anaerobic digestion by alternating with and under anoxic and anaerobic conditions, the membrane separation device is composed of a pressurized membrane separator, the pressurized membrane separator is a flow rate adjustment tank and the Separation membrane provided outside the flow adjustment tank Characterized in that eojineun.

Anaerobic digestion, intermittent aeration, membrane separation, pressurization, dipping, ammonia degassing

Description

Anaerobic digestive fluid processing apparatus and method {Method and apparatus for treating anaerobic digestive fluid}

The present invention relates to an anaerobic digestion liquid treatment apparatus and method, and more particularly, to provide an anaerobic digestion liquid treatment apparatus and method capable of effectively removing high concentrations of organic components, nitrogen and phosphorus contained in the anaerobic digestion liquid of a high concentration organic waste. The purpose is.

Anaerobic digestion of food waste, livestock manure, sewage sludge and high concentration organic wastes incorporating them has a relatively high concentration of organic components, nitrogen and phosphorus compared to general wastewater, and changes in water quality according to seasonal changes in Korea. Have

Accordingly, a conventional general sewage and wastewater treatment process, for example, a BNR (Biological Nitrogen Removal) process having a configuration of <pretreatment → anoxic tank, anaerobic tank, aeration tank → sedimentation tank → discharge> or <pretreatment → single reaction tank (oxygen, anaerobic, SBR (Sequencing Batch Reactor) process, which consists of aerobic and sedimentation induction) → discharge>, is difficult to settle due to the nature of anaerobic digestion of high concentration organic wastes, and therefore, high concentration of organic matter contained in the anaerobic digestion It is difficult to effectively remove dust, nitrogen and phosphorus.

In order to solve this problem, a combination process of an immersion type membrane separation process for separating and removing a polymer material using the BNR process and a separator has been developed, but in the case of combining the BNR process composed of two or more bioreactors with a membrane, A separation membrane is added together with the above bioreactor, and there is a problem in that economic efficiency is deteriorated by adding a transfer facility between the bioreactors.

The present invention has been made to solve the above problems, to provide an anaerobic digestion liquid treatment apparatus and method that can effectively remove the high concentration of organic components, nitrogen and phosphorus contained in the anaerobic digestion of high concentration organic wastes. There is this.

Anaerobic digestion liquid treatment apparatus according to the present invention for achieving the above object in the anaerobic digestion liquid processing apparatus for treating the anaerobic digestion liquid of high concentration organic waste, consisting of a combination of intermittent aeration tank and membrane separation device, the intermittent aeration tank, aeration By repeating the process and the non-aeration process in time series to alternately repeat the conditions in the intermittent aeration tank to aerobic, anaerobic and anaerobic conditions to remove organic components, nitrogen and phosphorus in the anaerobic digestion liquid, the membrane separation device Is composed of a pressurized membrane separator, the pressurized membrane separator is characterized in that consisting of a flow rate adjustment tank and a separator provided outside the flow rate adjustment tank.

An ammonia degassing apparatus is further provided at the front end of the intermittent aeration tank, and the ammonia degassing apparatus includes ammonia degassing tank and a pH adjusting means for administering a pH adjusting agent in the anaerobic digestion liquid to convert nitrogen components contained in the anaerobic digestion liquid into ammonia. And ammonia degassing promoting means for promoting deaeration of ammonia in the anaerobic digestion liquid.

In addition, an agglomeration tank and a centrifugal dehydrator are sequentially provided between the ammonia degassing tank and the intermittent aeration tank, and the agglomeration tank serves to agglomerate floating and dissolved solid components contained in the anaerobic digestion liquid. The solid component in the anaerobic digestion liquid may be removed by solid-liquid separation of the anaerobic digestion liquid passed through the flocculation tank. In addition, an activated carbon filtration device may be further provided at the rear end of the membrane separation device.

The anaerobic digestion liquid treating apparatus according to the present invention includes an ammonia degassing tank for degassing the nitrogen component contained in the anaerobic digestion liquid, and a floating and dissolved solid component included in the anaerobic digestion liquid provided at the rear end of the ammonia degassing tank. A centrifugal dehydrator which solidifies and separates the flocculation tank and the anaerobic digestion liquid passed through the flocculation tank to remove solid components in the anaerobic digestion liquid; By intermittently repeating the conditions in the intermittent aeration tank to the aerobic and anaerobic and anaerobic conditions, the intermittent aeration tank serves to remove organic components, nitrogen and phosphorus in the anaerobic digestion liquid, and the treated water discharged from the intermittent aeration tank. The polymer by separating the remaining polymer Another feature that comprises a membrane separation device that serves to remove the residual contaminants contained in and the activated carbon filtration device which is provided at the rear end of the membrane separation device to remove residual contaminants of the membrane separation treatment water. It is done.

The membrane separator may be composed of a pressurized or immersed membrane separator, the pressurized membrane separator is provided outside the flow rate adjustment tank, the flow rate adjustment tank is supplied to the treated water in the flow rate adjustment tank is included in the treated water By separating the polymer material may be composed of a separator for removing the residual contaminants contained in the polymer material. In addition, the immersion type membrane separation device is provided in the membrane separation tank, the membrane separation tank and the remaining water contained in the polymer material by separating the high molecular material contained in the treated water by receiving the treated water in the membrane separation tank It can be composed of a separator that removes contaminants.

Anaerobic digestion liquid treatment method according to the present invention is an ammonia degassing step of removing the nitrogen component contained in the anaerobic digestion liquid, a flocculation step of flocculating the floating, dissolved solid components contained in the anaerobic digestion liquid, and the coagulation tank Centrifugal dehydration to remove solids in anaerobic digestion by solid-liquid separation of anaerobic digestion, and aeration and non-aeration processes are repeated in time series to alternately repeat the conditions in the intermittent aeration tank under aerobic, anaerobic and anaerobic conditions. The intermittent aeration step of removing organic components, nitrogen and phosphorus components in the digestive fluid, and the remaining polymer material in the treated water is separated from the treated water that has undergone the intermittent aeration step by using a membrane separator to remove contaminants contained in the polymer material. After removing the membrane separation step and the membrane separation step, Using a Christmas filtration devices, including the activated carbon filtration step to remove the film by adsorbing pollutants remaining in the water separation process is characterized in that formed.

The ammonia degassing step may be configured to increase the pH of the anaerobic digestion liquid to 11 or more by administering a pH adjuster in the anaerobic digestion liquid to convert nitrogen components in the anaerobic digestion liquid to ammonia, and to degas the ammonia. .

In addition, the coagulation step may include a process of adjusting the pH of the anaerobic digestion liquid to 6 to 8 and administering a coagulant in the anaerobic digestion liquid.

The sludge produced in the intermittent aeration step and the membrane separation step may further include being returned to the ammonia degassing step to undergo the ammonia degassing step, the coagulation step, and the centrifugal dehydration step again.

Anaerobic digestion treatment apparatus and method according to the present invention has the following effects.

Intermittent aeration and membrane separation can effectively remove nitrogen and phosphorus as well as organic matter contained in the anaerobic digestion of high concentration organic waste. In addition, as the nitrogen component in the digestion liquid is removed to a certain level through ammonia degassing before performing the intermittent aeration, the efficiency of the intermittent aeration and the membrane separation process can be improved.

Hereinafter, an anaerobic digestion fluid processing apparatus and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram of an anaerobic digestion liquid treatment apparatus according to an embodiment of the present invention.

As shown in Figure 1, the anaerobic digestion treatment apparatus according to an embodiment of the present invention is largely ammonia degassing tank 110, coagulation tank 120, centrifugal dehydrator 130, intermittent aeration tank 140 and membrane separation device It consists of a combination of 150.

The ammonia degassing tank 110 lowers the nitrogen concentration of the anaerobic digestion liquid to a predetermined level prior to removing the nitrogen (N) component in the anaerobic digestion liquid through the intermittent aeration tank 140 and the membrane separation device 150. As a role, specifically, the nitrogen concentration in the anaerobic digestion liquid may be lowered by injecting air into the ammonia degassing tank 110 to degas the ammonia (NH ₃ ) gas in the anaerobic digestion liquid. At this time, one side of the ammonia degassing tank 110 for degassing the ammonia gas may be further provided with an diffuser for injecting air. Here, in addition to the method of degassing ammonia through air, the ammonia degassing tank 110 may be heated through a heating means to degas the ammonia or ammonia through the stirring means. Collectively, it can be referred to as ammonia degassing promoting means.

On the other hand, the nitrogen component in the anaerobic digestion liquid is mostly present in the form of ammonium ions (NH ₄ ⁺ ) or ammonia (NH ₃ ), and ammonium ions (NH ₄ ⁺ ) are not degassed by air injection. Accordingly, ammonium ions (NH ₄ ⁺ ) in the anaerobic digestion liquid need to be converted into ammonia (NH ₃ ) gaseous form, and the conversion of ammonium ions (NH ₄ ⁺ ) to ammonia (NH ₃ ) is a pH adjuster, namely caustic soda. It is possible to increase the pH of the anaerobic digestion liquid to 11 or more by adding alkali agents such as these. At this time, the pH adjuster may be administered by a pH adjuster administration means (not shown) provided on one side of the ammonia degassing tank (110).

In addition, in lowering the nitrogen concentration of the anaerobic digestion liquid through the ammonia degassing tank 110, the C / N ratio (carbon / nitrogen ratio) should be considered. In the subsequent intermittent aeration biological reaction process, since nitrogen can be removed through biological denitrification, an appropriate amount of nitrogen is removed to maintain an appropriate C / N ratio for the biological denitrification.

Next, the coagulation tank 120 serves to aggregate the floating and dissolved solid components contained in the anaerobic digestion fluid. In order to agglomerate, first, the pH of the anaerobic digestion liquid raised in the ammonia degassing process needs to be lowered and converted into an environment that is easy to coagulate. The pH coagulant such as sulfuric acid (H2SO4) solution is injected to optimize the coagulation according to the characteristics of the coagulant In the case of using a flocculant such as ALUM, the pH of the anaerobic digestion liquid can be adjusted to about 6. At this time, as in the ammonia degassing tank 110, one side of the flocculation tank 120 may be further provided with a pH adjusting means (not shown) for pH adjusting agent administration.

The centrifugal dehydrator 130 is provided at the rear end of the flocculation tank 120 to perform a solid-liquid separation process for the anaerobic digestion liquid, and separates solid components such as aggregates in the anaerobic digestion liquid from the liquid through the difference in specific gravity. Do it. Here, the aggregation aid may be administered to promote the solid-liquid separation in the centrifugal dehydrator (130).

Next, the intermittent aeration tank 140 repeats the aeration process and the non-aeration process in time series to alternately repeat the conditions in the intermittent aeration tank 140 under aerobic conditions, anoxic and anaerobic conditions. It serves to remove nitrogen (N) and phosphorus (P) as well as organic matter in the anaerobic digestion. At this time, the sludge discharged from the intermittent aeration tank 140 is conveyed to the ammonia degassing tank 110 and then disposed of through the flocculation tank and the centrifugal dehydrator.

Specifically, under the aerobic conditions of the intermittent aeration tank 140, the organic nitrogen and ammonia nitrogen (NH4-N) present in the anaerobic digestion liquid is converted into nitric acid nitrogen (NO3-N) by the nitrification reaction, and under the anoxic conditions The nitrate nitrogen produced by the nitrification reaction is converted to nitrogen gas and denitrified. In addition, the phosphorus component in the anaerobic digestion solution proceeds with the release of phosphate under anaerobic conditions, and is ingested by microorganisms in the form of phosphate (poly-P) of organic acids under aerobic conditions, accumulated in cells, and then removed through sludge discharge.

Finally, the membrane separation device 150 may be of a pressure type or immersion type, when the pressure separation membrane is composed of a flow regulating tank and a separation membrane provided outside the flow regulating tank. The flow rate adjusting tank of the pressurized membrane separator serves to secure a certain flow rate so as to stably supply the treated water discharged from the intermittent aeration tank 140 to the pressurized membrane separator, and the separator provided outside the flow regulating tank provides a pipe. By receiving the treated water from the flow adjustment tank through the separation of the remaining polymer material contained in the treated water serves to remove the contaminants contained in the polymer material.

On the other hand, when the immersion type membrane separation device is composed of a membrane separation tank, and the separation membrane provided in the membrane separation tank. Membrane separation tank of the immersion membrane separation device is added to the diffuser can remove the sludge layer formed on the surface of the immersion membrane.

In addition to the ammonia degassing tank 110, the coagulation tank 120, the centrifugal dehydrator 130, the intermittent aeration tank 140, and the membrane separation device 150, an activated carbon filtration device 160 may be further provided. The filtration device 160 is provided at the rear end of the membrane separation device. The activated carbon filtration device 160 serves to adsorb and remove contaminants remaining in the treated water, using the activated carbon, with respect to the treated water treated by the membrane separation device 150. At this time, the activated carbon filtration device 160 is made of a condensed activated carbon filtration method that consolidates the filter media layer with activated carbon to remove adsorption of dissolved organic matter and particulate matter in the treated water or dissolved organic matter and particulate matter in the treated water. The material may be configured in a gravity activated carbon filtration method in which the material is dropped by gravity and adsorbed onto the activated carbon.

The anaerobic digestion treatment apparatus according to the embodiment of the present invention has been described above. Hereinafter, the operation of the anaerobic digestion treatment apparatus, that is, the anaerobic digestion treatment method according to an embodiment of the present invention will be described. Figure 2 is a flow chart for explaining the anaerobic digestion treatment method according to an embodiment of the present invention.

First, anaerobic digestive fluid is prepared. The anaerobic digestion fluid refers to a result of the high concentration of organic waste in which food waste, livestock manure and sewage sludge are combined after the anaerobic digestion process in the anaerobic digester.

The ammonia degassing process is performed for the anaerobic digestion liquid (S201). The ammonia degassing process is a process of lowering the nitrogen concentration of the anaerobic digestion liquid below a predetermined level by injecting air into the ammonia degassing tank 110 through an acid pipe to degas the ammonia in the anaerobic digestion liquid. Since nitrogen in the anaerobic digestion liquid is present in the form of ammonium ions or ammonia, ammonia deaeration is used to lower the nitrogen concentration of the anaerobic digestion liquid. At this time, the ammonium ions are not degassed by air injection, so it is necessary to convert the ammonium ions into ammonia gas, and the conversion to ammonia gas is made possible by raising the pH of the anaerobic digestion liquid to 11 or more.

The anaerobic digestion liquid subjected to the ammonia degassing process is delivered to the coagulation tank 120 and undergoes the coagulation process (S202). The agglomeration process is a process of agglomeration and removal of the suspended and dissolved solids contained in the anaerobic digestion fluid through a coagulant, and the pH of the anaerobic digestion fluid needs to be adjusted to neutral, that is, 6 to 8 level for ease of aggregation. have.

In the state in which the aggregation process is completed, solid-liquid separation of the anaerobic digestion liquid using a centrifugal dehydrator 130, through which solid components such as aggregates in the anaerobic digestion liquid are removed (S203). The liquid component separated by the centrifugal dehydrator 130 is delivered to the intermittent aeration tank 140 through the first treatment tank.

The anaerobic digestion liquid, which has undergone the ammonia degassing, coagulation, and centrifugal dehydration processes, removes nitrogen, phosphorus, and organics in earnest through an intermittent aeration process (S204). Specifically, in the intermittent aeration process, the aeration process and the non-aeration process are repeated in time series. The aerobic conditions are formed through the aeration process, and the organic nitrogen and ammonia nitrogen (NH ₄ -N) present in the anaerobic digestion fluid are converted into nitrate nitrogen (NO ₃ -N) by the aerobic condition, and the phosphate of the organic acid. It is taken up by microorganisms in the form of (poly-P), accumulated in cells and then removed through sludge discharge. In addition, anoxic and anaerobic conditions are formed by the non-aerobic process. Nitric acid nitrogen is converted to nitrogen gas and denitrated by anoxic conditions, and phosphate is released under anaerobic conditions.

The sludge is discharged from the intermittent aeration tank 140 by the intermittent aeration process. The sludge is returned to the ammonia degassing tank 110, and the ammonia degassing process is performed again in the ammonia degassing tank 110.

On the other hand, the treated water treated by the intermittent aeration process is subjected to the membrane separation process via the second treatment tank (S205). The membrane separation process is carried out in the pressurized or immersed membrane separation apparatus. When the pressurized membrane separation apparatus is taken as an example, the separation membrane provided outside the flow regulating tank corresponding to the second treatment water tank is treated by the flow regulating tank through a pipe. The pollutants contained in the polymer material are removed by receiving water and separating the remaining polymer material contained in the treated water. At this time, the remaining sludge is again subjected to the ammonia degassing process similarly to the sludge of the intermittent aeration tank 140.

In the above, the anaerobic digestion liquid treatment method according to an embodiment of the present invention has been described. After the intermittent aeration process, the activated carbon filtration process may be further applied. Through the activated carbon filtration process (S206), it is possible to adsorb and remove the contaminants remaining in the treated water to the treated water treated by the membrane separation device 150.

1 is a block diagram of an anaerobic digestion solution processing apparatus according to an embodiment of the present invention.

Figure 2 is a flow chart for explaining the anaerobic digestion treatment method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: ammonia degassing tank 120: flocculation tank

130: centrifugal dehydrator 140: intermittent aeration tank

150: membrane separation device 160: activated carbon filtration device

Claims (14)

In the anaerobic digestion liquid treatment apparatus for treating the anaerobic digestion liquid of high concentration organic waste, It consists of a combination of intermittent aeration tank and membrane separation device, The intermittent aeration tank performs a time series repetition of an aeration process and a non-aeration process to alternately repeat the conditions in the intermittent aeration tank under aerobic, anaerobic and anaerobic conditions, thereby removing organic, nitrogen and phosphorus components in the anaerobic digestion fluid. , The membrane separator is composed of a pressurized membrane separator, the pressurized membrane separator is composed of a flow regulating tank and a separator provided outside the flow regulating tank, Ammonia degassing apparatus is further provided at the front end of the intermittent aeration tank, The ammonia degassing apparatus includes an ammonia degassing tank, a pH adjusting agent administration means for converting nitrogen components contained in the anaerobic digestion liquid into ammonia by administering a pH adjusting agent in the anaerobic digestion liquid, and promoting ammonia degassing to promote degassing of ammonia in the anaerobic digestion liquid. Anaerobic digestion treatment apparatus, characterized in that consisting of means. delete According to claim 1, Agglomeration tank and the centrifugal dehydrator is sequentially provided between the ammonia degassing tank and the intermittent aeration tank, The flocculation tank serves to agglomerate floating and dissolved solids contained in the anaerobic digestion fluid. The centrifugal dehydrator is anaerobic digestion liquid processing apparatus, characterized in that for performing solid-liquid separation of the anaerobic digestion liquid passed through the flocculation tank to remove solid components in the anaerobic digestion liquid. 2. The anaerobic digestion apparatus of claim 1, further comprising an activated carbon filtration device at a rear end of the membrane separation device. In the anaerobic digestion liquid treatment apparatus for treating the anaerobic digestion liquid of high concentration organic waste, An ammonia degassing tank for degassing nitrogen contained in the anaerobic digestion liquid; An agglomeration tank provided at a rear end of the ammonia degassing tank to agglomerate floating and dissolved solid components contained in the anaerobic digestion liquid; A centrifugal dehydrator for solid-liquid separation of the anaerobic digestion liquid passed through the flocculation tank to remove solid components in the anaerobic digestion liquid; It is provided at the rear end of the centrifugal dehydrator, and repeats the aeration process and the non-aeration process in time series to remove the organic, nitrogen and phosphorus components in the anaerobic digestion liquid by alternately repeating the conditions in the intermittent aeration tank under aerobic, anaerobic and anaerobic conditions. Intermittent aeration tank that plays a role; A membrane separation device which serves to remove residual contaminants contained in the polymer material by separating residual polymer material in the treated water from the treated water discharged from the intermittent aeration tank; And An anaerobic digestion solution processing apparatus, characterized in that it comprises an activated carbon filtration device which is provided at the rear end of the membrane separation device to remove residual contaminants of the membrane separation treatment water. The method of claim 5, wherein the pH adjusting agent is administered to one side of the ammonia degassing tank to convert the nitrogen component in the anaerobic digestion liquid into ammonia, and the ammonia degassing promoting means for promoting deaeration of the ammonia Anaerobic digestion treatment apparatus, characterized in that further provided. The anaerobic digestion treatment apparatus according to claim 5, further comprising a pH adjuster administration means for adjusting the pH of the anaerobic digestion liquid and a flocculant administration means for administering a flocculant to one side of the flocculation tank. The anaerobic digestion apparatus according to claim 5, wherein the membrane separator is composed of a pressurized or immersed membrane separator. The method of claim 8, wherein the pressurized membrane separation device is included in the polymer material by separating the polymer material contained in the treated water by receiving the treated water provided in the flow regulating tank and the flow adjusting tank provided outside the flow adjusting tank. Anaerobic digestion fluid processing apparatus, characterized in that consisting of a separator for removing residual contaminants. The method of claim 8, wherein the immersion type membrane separation device is provided inside the membrane separation tank, the membrane separation tank is supplied with the treated water in the membrane separation tank to separate the polymer material contained in the treated water by the polymer material Anaerobic digestion treatment device, characterized in that consisting of a separator for removing residual contaminants contained in. In the anaerobic digestion liquid treatment method of treating the anaerobic digestion liquid of high concentration organic waste, Ammonia degassing to remove nitrogen components contained in the anaerobic digestion liquid; An agglomeration step of agglomerating the floating and dissolved solid components contained in the anaerobic digestion liquid; Centrifugal dehydration step of removing the solids in the anaerobic digestion liquid by solid-liquid separation of the anaerobic digestion liquid passed through the flocculation step; An intermittent aeration step of removing the organic, nitrogen and phosphorus components in the anaerobic digestion liquid by repeating the aeration process and the non-aeration process in a time series so that the conditions in the intermittent aeration tank are alternately repeated between the aerobic and anaerobic and anaerobic conditions; A membrane separation step of removing contaminants contained in the polymer material by separating the residual polymer material in the treated water using a membrane separation device for the treated water that has undergone the intermittent aeration step; And After the membrane separation step, an activated carbon filtration process comprising the activated carbon filtration step of adsorbing and removing the remaining contaminants of the membrane separation treatment water using the activated carbon filtration device. The method of claim 11, wherein the ammonia degassing step, Administering a pH adjusting agent in the anaerobic digestion liquid to increase the pH of the anaerobic digestion liquid to 11 or more, thereby converting nitrogen components in the anaerobic digestion liquid into ammonia; Anaerobic digestion liquid treatment method comprising the process of degassing the ammonia. The method of claim 11, wherein the aggregation step, Adjusting the pH of the anaerobic digestion liquid to 6-8; Anaerobic digestion treatment method comprising the step of administering a flocculant in the anaerobic digestion fluid. 12. The anaerobic treatment according to claim 11, wherein the sludge produced in the intermittent aeration step and the membrane separation step is returned to the ammonia degassing step, and further includes the ammonia degassing step, the coagulation step, and the centrifugal dehydration step. How to treat digestive fluids.

Images