JP2004136268A - Apparatus for removing manganese in water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which, although simple and small, can highly efficiently remove manganese components in underground water etc., by rapid filtration at a rate of 120m/day or more without using chemicals such as an oxidizing agent and a flocculant. <P>SOLUTION: The manganese removing apparatus is provided with a gas-liquid contacting mechanism (4) which is connected downstream of a filter for catching iron in raw water with a filter medium after oxidizing and insolubilizing it and performs aeration for increasing the dissolved oxygen concentration in the raw water, a filter tank (3) which accommodates a filter medium bed (2) having a catalytic function promoting the oxidation of manganese in the raw water, and a filtrate discharge port (9) installed in the filter tank (3). <P>COPYRIGHT: (C)2004,JPO

Description

【００９４】
比較例として、気液接触機構によるエアレーションを行わず除鉄装置１００から処理水を直接本発明の装置の濾過槽３に注入した以外は上記実験と同一条件により除マンガンテストを行った。その結果を表２に示す。
【００９５】

【００９６】
表１および表２の結果から、エアレーションを行った本発明実施例によれば処理水のマンガン濃度を水質基準で許容される０．０５ｍｇ／ｌ以下に低減させることができるが、エアレーションなしの比較例によれば処理水のマンガン濃度は０．１６４〜０．２４８ｍｇ／ｌであり、許容濃度まで低減できないことが判る。
【００９７】
実施例２
次ぎに、図７の除鉄装置１００を使用して兵庫県柏原町において採取した地下水を処理することによって鉄分濃度を減少させた水を被処理水として、図１の装置の中エアレーション手段として気液接触機構を使用するかわりにホースによるエアレーションを行ってマンガン除去テストを行った。すなわち除鉄装置１００からの処理水を内径１０ｍｍのホースから図１の装置の濾過槽３に水面から１ｍの高さから流速１リットル／分で落下させることによりエアレーションを行った。濾材層としては粒径０．６ｍｍの黒砂（鉄バクテリア集落が存在する濾材層）を使用した。濾過速度は１２０ｍ／日であった。被処理水および処理後の浄水（処理水）のマンガン濃度および被処理水の鉄濃度を１日１回決まった時間に測定した。被処理水の溶存酸素濃度は平均５ｍｇ／ｌで、ホースによるエアレーションを行った直後の水の溶存酸素濃度は７．２であった。測定結果を表３に示す。
【００９８】

【００９９】
実施例３
濾材層として粒径２ｍｍの濾過砂に鉄バクテリアであるレプトスリックス（Ｌｅｐｔｏｔｈｒｉｘ）を移植した濾材を使用した以外は実施例２と同一条件で除マンガンテストを行った。マンガン濃度のテスト結果を表４に示す。
【０１００】

【０１０１】
比較例として、濾材層として鉄バクテリアを移植していない普通の濾過砂（粒径２ｍｍ）を使用した以外は実施例３と同一条件で除マンガンテストを行った。その結果を表５に示す。
【０１０２】

【０１０３】
表４と表５の結果から、エアレーションを行っても鉄バクテリアの集落が存在しない砂濾過層では充分な除マンガン効果を挙げることができないことが判る。
【０１０４】
【発明の効果】
以上述べたように、本発明によれば、本発明の装置は原水中の鉄を酸化させ不溶化した後濾材によって捕捉する濾過装置の後段に接続されており、原水中の鉄分は前段の装置によりほとんど捕捉されているので、本発明に供給される原水中の鉄の濃度は大幅に減少している。これによって濾材層における鉄とマンガンの酸化における競合がなくなり、マンガンの酸化にとって好適な環境が形成される。エアレーション手段により原水中の溶存酸素濃度が増加し、マンガンの酸化を触媒する機能を有する濾材層におけるマンガンの酸化が一層促進される。酸化したマンガンは濾材層に沈着し、濾過水が濾過槽の濾過水取出し口から取出される。本発明の装置によれば、酸化剤や凝集剤等の薬品を使用することなく、簡単で小型の装置により、１２０ｍ／日以上の急速濾過により高能率で地下水等のマンガン成分を除去することができる。
【０１０５】
濾材層が鉄バクテリアの集落が存在する濾材層である場合は、エアレーションにより増加した原水中の溶存酸素は、鉄バクテリアの増殖を促進するように作用する。
【０１０６】
濾材層がマンガン砂を主成分とする濾材層である場合は、エアレーションにより増加した原水中の溶存酸素は、マンガン砂による接触酸化を促進するように作用する。
【０１０７】
本発明の１側面において、エアレーション手段は規則充填体とアダプターを備える気液接触機構からなり、各充填体構成要素は隣合う充填体構成要素と非接触状態で互いに平行に延長するとともにアダプターにより原水供給管に直結されており、原水供給管から各充填体構成要素に流下した原水は隣合う充填体構成要素に移って原水の流れに不均一を生じることなく流下するので、均一な気液接触が行われ、エアレーションが均一に行われ、マンガン除去も最高の効率で行うことができる。
【０１０８】
本発明の１側面において、除マンガン装置は、濾過水供給停止時に該原水供給管からの原水の供給を停止するとともに濾過水を該原水供給管に返送して濾材層中を循環させる濾過水循環手段をさらに備えているので、濾過水が不要で濾過水の供給を停止する期間においても濾過水を原水供給管に返送し濾材層中を循環させるとともにエアレーションを継続して行うことにより、濾過水供給停止期間中も濾材層中の鉄バクテリアその他の微生物に溶存酸素が充分に供給され、その結果微生物の酸素不足による死滅、減少が防止され、濾過水供給を再開する時に濾材層における除マンガン効果の減少を防止することができる。
【０１０９】
本発明の１側面において、除マンガン装置は、該濾材層中に埋設された逆洗管をさらに備え、該逆洗管は、該濾材層上部に蓄積した濾材層閉塞物を逆洗により除去するために充分な深さであるとともに該逆洗管の下方にできるだけ厚い濾材層の部分が存在するような深さに埋設されていることにより、濾材層上部に蓄積した濾材層閉塞物は逆洗により洗い流されて除去される一方逆洗管の下方の濾材層には逆洗の影響はおよばないので、濾材層の下方の濾材層中に存在する鉄バクテリアその他の微生物の集落は破壊されることがなく、逆洗後に装置の運転を再開した時濾材層のこの部分に存在する微生物による除マンガン効果が存続維持され、除マンガン装置全体としての除マンガン効果を向上させることができる。
【図面の簡単な説明】
【図１】本発明にかかる除マンガン装置の１実施形態を模式的に示す断面図である。
【図２】気液接触機構を模式的に示す斜視図である。
【図３】規則充填体の一部を拡大して示す斜視図である。
【図４】充填体構成要素集合体の横断面図である。
【図５】原水分配管の横断面図である。
【図６】濾過槽および目詰まりほぐし棒保持部材を模式的に示す斜視図である。
【図７】本発明の装置の前段に接続される除鉄装置の１例を示す斜視図である。
【図８】本発明の他の実施形態を模式的に示す図１と同様の断面図である。
【図９】同実施形態の濾過槽および目詰まりほぐし棒保持部材を模式的に示す斜視図である。
【図１０】濾過水循環手段の変更例を示す図８と同様の断面図である。
【符号の説明】
１　　除マンガン装置
２　　濾材層
３　　濾過槽
４　　気液接触機構
５　　規則充填体
９　　濾過水取出し口
２０　目詰まりほぐし棒保持部材往復動機構
２８　目詰まりほぐし棒保持部材
４２　目詰まりほぐし棒
５８　アダプター
６０　充填体構成要素
６４　充填体構成要素集合体[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an apparatus for removing manganese in water such as groundwater, and in particular, treats raw water at a high speed of 120 m / day or more without using chemicals such as an oxidizing agent and a flocculant, while using a simple and small apparatus. Manganese removal device.
[0002]
[Prior art]
Groundwater is used as raw water for tap water and in industries that require a large amount of water, such as the food industry, soft drinks, brewing, public baths, and dyeing.Currently, iron and manganese components contained in groundwater are large. In question. Iron and manganese are necessary ingredients for the human body, but if they exceed a certain amount, they will give water a metallic taste, cause red water and black water, and will not only be unsuitable for drinking, but also various problems in these industries Occurs. Also, drainage of groundwater before foundation work is an indispensable step in building foundation work, but if groundwater contains a large amount of iron and manganese, it is prohibited by law to discharge it to the sewer as it is. There is a problem that iron and manganese in groundwater must be removed before being discharged.
[0003]
Currently, the most widely used iron and manganese removal equipment is to add an oxidizing agent such as sodium hypochlorite and a coagulant such as aluminum polychloride (PAC) to raw water to oxidize iron and manganese dissolved in water. It is made into insoluble iron oxide and manganese oxide, which are removed by filtration with filter sand.
[0004]
However, in a water treatment apparatus of the type in which the oxidizing agent or the flocculant is injected, a relatively large amount of the oxidizing agent or the flocculant is consumed, so that the purchase cost of these is large. Hypochlorous acid, which is used as an oxidizing agent, remains in the purified water after the oxidation of iron and manganese, producing trihalomethane, a carcinogen. It has to be processed through a carbon layer, which is uneconomical. If the installation of the activated carbon layer is forgotten from economic considerations, the filtered water is constantly analyzed and monitored to prevent the generation of trihalomethane due to excessive injection of the oxidizing agent. It is necessary to adjust the injection amount, and there is a disadvantage that the maintenance cost is increased in addition to the purchase cost of the medicine. The water treatment system using this chemical injection system consists of an aeration tank, a coagulation tank, a sedimentation tank, a sand filtration tower, an iron removal / manganese removal tower, and a chemical solution tank. Since a large installation space is required, there is a problem that the apparatus cannot be installed in an environment where the installation space is limited, such as in an urban area. Furthermore, the filtered sand used in this chemical injection type water treatment device must be replaced from time to time due to clogging due to the accumulation of impurities.In that case, since the sand contains chemicals, it must be treated as industrial waste. In addition, there are inconveniences such as the abandoned places being restricted.
[0005]
In order to eliminate the above-mentioned drawbacks of the conventional water treatment apparatus using a chemical injection method, the present applicant has proposed to dissolve iron, manganese and other soluble components in groundwater by using an oxidizing agent or a coagulating agent, as described in Patent Document 1. The present invention provides an apparatus for treating by oxidizing and insolubilizing with a simple and small apparatus without using chemicals such as agents.
[0006]
According to this water treatment device, the jet water flow entrains the air into a large number of small bubbles by introducing air into the jet nozzle from an air introduction pipe opening into the jet nozzle while the raw water is made into a jet water flow by the jet nozzle, The jet stream containing many air bubbles hits the water surface on the filter medium layer and intense aeration occurs in the water and on the surface of the filter medium.As a result, iron and manganese components in the water are oxidized and become insoluble components to form flocs or precipitate. It is configured to be trapped by the filter sand forming the filter medium layer.
[0007]
[Patent Document 1]
WO 02/34677
[0008]
[Problems to be solved by the invention]
According to water quality standards in Japan, the allowable iron concentration in tap water is 0.3 mg / l or less, and the allowable manganese concentration is 0.05 mg / l or less. As a result of the experiment, according to the apparatus described in WO 02/34677, the iron content in the groundwater can be sufficiently reduced to below this allowable concentration, but the concentration of manganese can be reduced, It was found that it was difficult to reduce the concentration below the allowable concentration.
[0009]
Conventionally, in order to remove manganese in groundwater, a contact filtration method using manganese sand as a filter medium and a method using iron bacteria are known in addition to the above-described method using a chemical injection method.
[0010]
In the contact filtration method, raw water is pre-chlorinated, then rapidly filtered using manganese sand as a filter material, and manganese in the raw water is contact-oxidized and removed on the surface of the manganese sand. According to this method, rapid filtration of 120 m / day or more is possible, so that raw water can be treated with high efficiency. ₂ ・ H ₂ O) is inert MnO ₂ ・ MnO ・ H ₂ Since it becomes O and loses catalytic oxidizing power, it is necessary to inject chlorine into raw water in advance so that manganese sand constantly restores catalytic oxidizing properties. Therefore, this method is ultimately one of the chemical injection methods, and is inevitable for the above-mentioned disadvantages of the chemical injection method.
[0011]
The method using iron bacteria utilizes the ability of iron bacteria to oxidize iron and manganese dissolved in water and oxidize them as insoluble iron and manganese oxide to deposit on the surface and inside of the body of bacteria. After adsorbing manganese, iron bacteria and water are continuously separated by sand filtration. Although this method does not require injection of chemicals, the filtration speed is limited to 10 to 30 m / day, and manganese removal of raw water cannot be performed with high efficiency by rapid filtration of 120 m / day or more.
[0012]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and does not use chemicals such as an oxidizing agent and a flocculant. It is intended to provide an apparatus capable of removing manganese components such as groundwater with high efficiency.
[0013]
[Means for Solving the Problems]
The manganese removing device of the present invention that achieves the above object is a device that removes manganese in raw water that is connected to the subsequent stage of a filtering device that oxidizes and insolubilizes iron in raw water and captures it with a filter medium, and removes manganese in raw water. Aeration means for performing aeration to increase the oxygen concentration, a filtration tank containing a filter medium layer having a catalytic function of promoting the oxidation of manganese in raw water, and a filtration water outlet provided in the filtration tank It is characterized by the following.
[0014]
In one aspect of the present invention, the filter medium layer is a filter medium layer in which colonies of iron bacteria exist.
[0015]
In another aspect of the present invention, the filter medium layer is a filter medium layer containing manganese sand as a main component.
[0016]
In another aspect of the present invention, the aeration means is a gas-liquid contact mechanism having a flow path forming structure for dividing raw water supplied from a raw water supply pipe disposed at an upper part of the apparatus into a plurality of flow paths and flowing down the flow. The gas-liquid contact mechanism includes a regular packed body and a plurality of adapters for supplying raw water from the raw water supply pipe to the regular packed body, and the regular packed body has a plurality of thread-like or band-like shapes. Each of the filler components extends vertically in parallel with each other in a non-contact state with an adjacent filler component, and the adapter is formed integrally with the filler component, The adapter is directly connected to the raw water supply pipe without branching from another adapter.
[0017]
In another aspect of the present invention, a manganese removing device comprises: a clogging loosening rod holding member to which a plurality of clogging loosening rods arranged such that tips are inserted into the surface layer of the filter medium layer; A mechanism for reciprocating the clog loosening rod holding member on a plane parallel to the surface of the filter medium layer.
[0018]
In another aspect of the present invention, the manganese removing device is configured to stop the supply of raw water from the raw water supply pipe when the supply of filtered water is stopped, and return the filtered water to the raw water supply pipe to circulate through the filter medium layer. It is characterized by further comprising a water circulation means.
[0019]
The filtered water circulation means includes a filtered water circulation pipe connecting the filtered water outlet and the raw water supply pipe, a water supply pump connected to the filtered water circulation pipe, and a filtration water circulation pipe. At the time of supplying water, supply filtered water and stop water supply to the filtered water circulation pipe.When stopping supply of filtered water, stop supplying filtered water and supply filtered water to the raw water supply pipe through the filtered water circulation pipe. A return valve, which is provided in the raw water supply pipe, passes the raw water when supplying the filtered water and stops the passage of the filtered water from the filtered water circulation pipe, and stops the passage of the raw water when the supply of the filtered water is stopped. And valve means for passing the filtered water from the filtered water circulation pipe.
[0020]
The filtered water circulating means includes a filtered water circulating outlet that is separate from the filtered water outlet, a filtered water circulating pipe that connects the filtered water circulating outlet with the raw water supply pipe, and a filtered water circulating pipe. A water supply pump connected thereto, a valve provided in the pipeline on the filtered water outlet side, which valve is opened when supplying filtered water and closed when supplying filtered water is stopped, and a valve provided in the raw water supply pipe, A valve means is provided for passing raw water during supply and stopping the passage of filtered water from the filtered water circulation pipe, and for stopping supply of filtered water, stopping the passage of raw water and passing filtered water from the filtered water circulation pipe. It can be configured as follows.
[0021]
In another aspect of the present invention, the manganese removing device further comprises a backwash tube embedded in the filter medium layer, and the backwash tube removes a filter medium layer blockage accumulated on the upper portion of the filter medium layer by backwashing. The filter is buried at such a depth that it is deep enough to allow the filter medium layer to be as thick as possible below the backwash tube.
[0022]
In another aspect of the present invention, there is provided a method of removing manganese in raw water after capturing iron in raw water with a filter medium, wherein the step of increasing dissolved oxygen concentration in raw water supplied from a raw water supply pipe by aeration. And passing the raw water through a filter medium layer having a catalytic function of promoting the oxidation of manganese; removing the filtered water that has passed through the filter medium layer; and supplying raw water from the raw water supply pipe when the supply of filtered water is stopped. Stopping and returning the filtered water to the raw water supply pipe to circulate through the filter medium layer and continuously perform aeration to maintain the dissolved oxygen concentration in the filtered water at a predetermined level. Is provided.
[0023]
[Action]
According to the present invention, the device of the present invention is connected to the subsequent stage of a filtration device that oxidizes and insolubilizes iron in raw water and then captures it with a filter medium.Since iron in raw water is mostly captured by the upstream device, The concentration of iron in the raw water supplied to the present invention is greatly reduced. This eliminates competition in the oxidation of iron and manganese in the filter medium layer, and creates a favorable environment for the oxidation of manganese. The concentration of dissolved oxygen in the raw water is increased by the aeration means, and the oxidation of manganese in the filter medium layer having a function of catalyzing the oxidation of manganese is further promoted. The oxidized manganese deposits on the filter medium layer, and the filtered water is taken out from the filtered water outlet of the filter tank.
[0024]
When the filter medium layer is a filter medium layer in which colonies of iron bacteria are present, the dissolved oxygen in the raw water increased by aeration is considered to act to promote the growth of iron bacteria.
[0025]
When the filter medium layer is a filter medium layer containing manganese sand as a main component, the dissolved oxygen in the raw water increased by aeration is considered to act to promote catalytic oxidation by manganese sand.
[0026]
In one aspect of the present invention, the aeration means comprises a gas-liquid contact mechanism comprising an ordered packing and an adapter, wherein each packing component extends parallel to each other in a non-contact state with an adjacent packing component and the raw water is supplied by the adapter. Raw water that is directly connected to the supply pipe and flows down from the raw water supply pipe to each packing element moves to the adjacent packing element and flows down without causing non-uniformity in the flow of raw water, so uniform gas-liquid contact Is performed, aeration is performed uniformly, and manganese removal can be performed with the highest efficiency.
[0027]
In one aspect of the present invention, the manganese removing device is a filtered water circulating means for stopping supply of raw water from the raw water supply pipe when the supply of filtered water is stopped, and returning filtered water to the raw water supply pipe to circulate through the filter medium layer. In addition, even during the period in which the filtration water is unnecessary and the supply of the filtration water is stopped, the filtration water is returned to the raw water supply pipe and circulated through the filter medium layer, and the aeration is continuously performed, so that the filtration water supply is performed. During the suspension period, the dissolved oxygen is sufficiently supplied to the iron bacteria and other microorganisms in the filter medium layer, so that the microorganisms are prevented from being killed or reduced due to lack of oxygen, and the manganese removal effect in the filter medium layer is reduced when the supply of the filtered water is resumed. Reduction can be prevented.
[0028]
In one aspect of the present invention, the manganese removing device further includes a backwash tube embedded in the filter medium layer, and the backwash tube removes a filter medium layer blockage accumulated on the upper portion of the filter medium layer by backwashing. The filter media layer is buried at a depth that is large enough to allow a portion of the filter media layer to be as thick as possible below the backwash tube. The backwash does not affect the filter media layer below the backwash tube while it is washed away by, and the colonies of iron bacteria and other microorganisms present in the filter media layer below the filter media layer are destroyed. Therefore, when the operation of the apparatus is resumed after the backwash, the manganese removing effect of the microorganisms present in this portion of the filter medium layer is maintained and the manganese removing effect of the entire manganese removing apparatus can be improved.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
The manganese removing device of the present invention is connected to a stage subsequent to a filtering device that oxidizes and insolubilizes iron in raw water and then captures the same with a filter medium. Groundwater containing a lot of manganese usually contains a lot of iron, but when iron and manganese coexist in the groundwater, iron oxidizes faster than manganese. Iron oxidized earlier than manganese deposits between the filter medium particles of the filter medium layer and reduces the effective surface area of the filter medium as an oxidation catalyst, which is disadvantageous in that manganese subsequently causes an oxidation reaction. In the present invention, a filter medium layer having a catalytic function of accelerating the oxidation of manganese in raw water is used as the filter medium layer. However, when iron and manganese coexist in raw water, the manganese oxidation catalytic function of the filter medium layer is impaired. Will be.
[0030]
In the present invention, iron removal and manganese removal of raw water are performed by a device arranged in two stages, and first, iron removal is performed by a device arranged in the preceding stage of the device of the present invention, and after the iron concentration is sufficiently reduced, The apparatus according to the present invention, which is arranged at the subsequent stage, oxidizes manganese and captures the manganese with a filter medium, thereby eliminating competition due to iron in oxidizing manganese and forming an environment suitable for manganese oxidation.
[0031]
In the present invention, as the filter medium layer having a catalytic function of accelerating the oxidation of manganese in raw water, either a filter medium layer in which colonies of iron bacteria exist or a filter medium layer containing manganese sand as a main component is used.
[0032]
As a filter medium layer in which iron bacterial settlements are present, manganese that has been oxidized is deposited on the surface or body of iron bacteria as a result of continuous manganese removal treatment for several months in a groundwater filtration device, and black sand in which the filtered sand exhibits a black color as a whole. So-called filtered sand may be used, or one obtained by transplanting an appropriate amount of iron bacteria into ordinary filtered sand may be used. Also, a mixture of these filter sands may be used.
[0033]
Various kinds of iron bacteria are known, but for the purpose of the present invention, for example, Leptothrix or Clonothrix can be used as a suitable iron bacterium.
[0034]
The manganese sand used in the filter medium layer mainly composed of manganese sand has manganese oxide (MnO) on the surface of the sand particles. ₂ ・ H ₂ O). As the filter medium layer, only manganese sand may be used, or manganese sand may be used as a main component, and one or more kinds of filter medium such as ordinary filter sand, ceramic balls, and fiber balls may be mixed.
[0035]
The particle size of the filter sand and other filter media used in each of the filter media layers is preferably about 2 mm to 6 mm in order to achieve rapid filtration of 120 m / day or more. It has been found that rapid filtration can be achieved.
[0036]
In the present invention, although the filter medium layer that captures oxidized manganese is a filter medium layer such as black sand or a filter medium layer containing manganese sand as a main component in which a conventionally known settlement of iron bacteria exists, a conventional manganese sand filter medium is used. It is possible to remove manganese in raw water by rapid filtration of 120 m / day or more without using the chemical injection method like a device using a bed and unlike a device using a conventional iron bacteria filter medium layer. This is due to the fact that the concentration of dissolved oxygen in the raw water is increased by aeration, in combination with the adoption of the two-stage method of first oxidizing and trapping the manganese and then oxidizing and trapping the iron.
[0037]
In the conventional contact filtration method using manganese sand, it is indispensable to inject chlorine into raw water in order to restore the oxidation catalyst function of manganese sand, and instead of this chlorine, the concentration of dissolved oxygen in raw water It was completely unexpected that increasing the amount of manganese promotes the oxidation of manganese and has the same manganese removal effect as the chlorine injection method.
[0038]
Further, the conventional method using iron bacteria has a limit of filtration speed of 10 to 30 m / day as described above, and it is considered that it is impossible to achieve rapid filtration of 120 m / day or more by this method. Was. According to the present invention, a simple method of increasing the concentration of dissolved oxygen in raw water surprisingly enabled rapid filtration of 120 m / day or more. The mechanism by which the increase in dissolved oxygen promotes manganese oxidation by iron bacteria is unknown, but the increase in dissolved oxygen promotes the growth of iron bacteria and the iron bacteria grow significantly in the filter media layer. It is considered that the oxidation of manganese in raw water by bacteria and the deposition on iron bacteria are promoted.
[0039]
As a result of the experiment, the dissolved oxygen concentration in the raw water should be 7 mg / l or more, and preferably 8 mg / l in order to make the concentration of manganese in the purified water 0.05 mg / l or less determined by the water quality standard by rapid filtration of 120 m / day or more. It has been found that it is desirable to set it to 1 or more.
[0040]
The specific method of aeration for increasing the dissolved oxygen in the raw water is not particularly limited. For example, the raw water to be treated is jetted from a nozzle or a hose onto the surface of a filtration tank containing a filter medium layer to cause aeration in the water. Aeration can also be performed by using various ordered packings, irregular packings, etc., by flowing raw water from above and blowing up air from below to perform gas-liquid contact. A particularly preferred method for achieving the above object is to use the gas-liquid contact mechanism described in Japanese Patent Application No. 2002-203669 filed by the present applicant. In this case, the aeration means comprises a gas-liquid contact mechanism having a regular packing and an adapter, and each packing component extends parallel to each other in a non-contact state with an adjacent packing component and is directly connected to the raw water supply pipe by the adapter. The raw water that has flowed down from the raw water supply pipe to each filler component moves to an adjacent filler component and flows down without causing unevenness in the flow of the raw water, so that uniform gas-liquid contact is performed, Aeration is performed uniformly, and a desired manganese removal efficiency can be obtained.
[0041]
Hereinafter, an embodiment of a manganese removal device according to the present invention will be described with reference to the accompanying drawings.
[0042]
First, an example of an apparatus for removing iron, which is disposed in a stage preceding the apparatus of the present invention, will be described with reference to FIG.
[0043]
FIG. 7 is a perspective view showing an example of the iron removing device, in which a part of the side wall of the filtration tank is cut away.
[0044]
The iron removing apparatus 100 includes, as main components, a filtration tank 103 containing a filter medium layer 102, a raw water supply pipe 104, a jet nozzle 105, and an air introduction pipe 106.
[0045]
A raw water supply pipe 104 for supplying raw water such as groundwater or river water to be filtered to the filtration tank 103 is connected to a water supply pump 107 by a rubber pipe 108. The water supply pump 107 is supplied with raw water from a raw water source. The raw water is supplied to the raw water transmission pipe 104 at a predetermined flow rate.
[0046]
The raw water supply pipe 104 is disposed above one end of the filter tank 103 so as to extend on a plane parallel to the surface of the filter medium layer 102.
[0047]
A plurality of jet nozzles 105 are provided to branch off from the raw water supply pipe 104 vertically. The upstream end of each jet nozzle 105 is fitted into the raw water supply pipe 104 such that the inside communicates with the raw water supply pipe 104, and the downstream end has a raw water jet port for jetting raw water as a jet water flow. Is formed.
[0048]
Each jet nozzle 105 is provided with an air introduction tube 106. The upstream end of each air introduction pipe 106 projects obliquely upward from the jet nozzle 105 so that the inside is open to the atmosphere, and the downstream end is located inside the jet nozzle 105 upstream of the raw water jet. It is open.
[0049]
In the filtration tank 103, the surface of the filter medium layer 102 is disposed below the jet nozzle 105 with a predetermined distance from the raw water jet port of the jet nozzle 105. The filter medium layer 102 is made of filter sand and has a function of filtering raw water by capturing oxide flocs and other foreign substances in raw water supplied as a jet stream supplied from a jet nozzle.
[0050]
A baffle plate 113 is provided between the raw water jet of the jet nozzle 105 and the surface of the filter medium layer 102 so as to be located parallel to the raw water feed pipe 104 and directly below the raw water jet of each jet nozzle 105. I have.
[0051]
At the bottom of the filter medium layer 102, a filter medium layer receiver 114 formed of a plate-like screen that supports the filter medium layer 102 is disposed at a predetermined height from the bottom surface of the filtration tank 103, and a lower portion formed below the filter medium layer receiver 114. A backwash tube 115 is arranged in the space 116.
[0052]
A filtered water outlet 117 is provided on the side wall 103 c of the filtration tank 103. An overflow gutter 118 is provided at one end of the filtration tank 3. One end of the overflow gutter 118 is closed by a side wall 103 b of the filtration tank 103, and the other end is closed by a lid 119.
[0053]
In this example, as a raw water water pipe reciprocating mechanism 120 that reciprocates the raw water water pipe 104 on a plane parallel to the surface of the filter medium layer 102, an electric motor that drives the screw box 121, the feed screw 122, and the feed screw 122, and A mechanism including a feed screw driving device 123 including a speed reduction mechanism is used.
[0054]
A roller (not shown) is attached at a position above the side walls 103a and 103b of the raw water transmission pipe 104 in order to smoothly and stably move the reciprocating movement of the raw water transmission pipe 104, and at the upper end of the side walls 103a and 103b. Are formed with guide grooves 129 through which these rollers are guided while rotating.
[0055]
At the time of raw water filtration, raw water is supplied to the jet nozzle 105 while maintaining the water depth on the surface of the filter medium layer 102 at a predetermined value, and the flow rate of the water at the jet nozzle 105 is set to, for example, 1.5 to 3 liter / min. As a result, air is sucked into the jet nozzle 105 from the air introduction pipe 106 opening into the jet nozzle 105 at a flow rate of, for example, 0.5 to 1 liter / min, while the jet water stream entrains the air. The jet water stream containing a large number of small bubbles and including the large number of bubbles is blown from the raw water jet port of the jet nozzle 105 onto the water surface on the filter medium layer 102, and intense aeration occurs on the water surface and the filter medium surface. By this aeration, soluble components such as iron in the water are oxidized to become insoluble components, and are trapped on the surface of the filter medium particles of the filter sand which form flocs or precipitate to form the filter medium layer 102. The filtered water from which these insoluble components and other foreign substances are filtered by the filter medium layer 102 is taken out from the filtered water outlet 117 to the outside.
[0056]
When the above-mentioned filtering action is continued, the flocs of oxides and other foreign substances accumulate on the surface of the filter medium layer 102 over time, and the filter function of the filter medium layer 102 decreases.
[0057]
In this case, the raw water supply pipe reciprocating mechanism 120 is operated while supplying the raw water and the air, and the raw water supply pipe 104 is reciprocated on a plane parallel to the surface of the filter medium layer 102, thereby ejecting the jet from the jet nozzle 105. Since the jet water flow is violently hit against the surface of the filter medium layer 102, the entire surface of the filter medium layer 102 is plowed, and the clogged state of the filter medium layer surface due to foreign matter is removed, and the filter medium layer 102 recovers its original filtration function. .
[0058]
Next, one embodiment of the manganese removing device of the present invention connected to the subsequent stage of the iron removing device 100 will be described with reference to FIGS.
[0059]
FIG. 1 is a cross-sectional view schematically showing one embodiment of the manganese removing device according to the present invention, FIG. 2 is a perspective view schematically showing a gas-liquid contact mechanism, and FIG. 6 shows a filter tank and a clogging loosening rod holding member. It is a perspective view which shows typically. 2 and 6, the housing and a part of the side wall of the filtration tank are not shown.
[0060]
In the present embodiment, the manganese removing device 1 includes, as main components, a filtration tank 3 containing a filter medium layer 2 and a gas-liquid contact mechanism 4 constituting an aeration unit of the present invention.
[0061]
First, the gas-liquid contact mechanism 4 will be described.
The gas-liquid contact mechanism 4 is disposed above the filtration tank 3, and as shown in FIG. 2, a plurality (20 in the illustrated embodiment) of the ordered packed body assembly is provided in a rectangular box-shaped housing 50 having an open bottom. The regular packed body 5 consisting of 64 is accommodated.
[0062]
At the top of the housing 50, a raw water supply main pipe 52 connected to a filtered water outlet 17 of the former stage iron removal device 100 by a hose is arranged, and the raw water supply main pipe 52 extends in parallel (shown in the drawing). (5 in the embodiment). A plurality (four in the illustrated embodiment) of raw water pipes 56 are provided at predetermined intervals on the lower surface of each raw water supply branch pipe 54 so as to project downward, and communicate with the raw water supply branch pipe 54. ing.
[0063]
In the housing 50, the regular packing 5 including a plurality of thread-like adapters 58 connected to the lower end of the raw water pipe 56 and a plurality of thread-like filler components 60 integrally formed with the adapters 58 is arranged. Have been.
[0064]
In this embodiment, as shown in FIG. 3 which is a perspective view showing a part of the ordered packing body 5 in an enlarged manner, the gas-liquid contact mechanism 4 has 20 vertically elongated members constituting the ordered packing body 5. It is composed of a rectangular parallelepiped filler component assembly 64 and an adapter 58. Each raw water pipe 56 supplies raw water, that is, water to be treated whose iron concentration has been greatly reduced by the iron removal device 100 at the preceding stage, to the corresponding one of the aggregates 64 (in the following description, "Raw water" treated in the apparatus of the present invention means treated water having a reduced iron concentration).
[0065]
Each assembly 64 has a cross-section in which a number of vertically extending thread-like filler components 60 are maintained at a predetermined distance from each other, that is, the adjacent filler components 60 are in a non-contact state and parallel to each other. They are arranged to form rows and columns. Each filler component 60 is arranged so as to maintain a non-contact state with the inner wall of the housing 50.
[0066]
At the upper end and lower end of each assembly 64, as shown in the cross-sectional view of FIG. 4, a plurality of spacers 66 made of a long member such as a steel bar are provided with a plurality of fillers constituting each row in FIG. It is arranged so as to extend in the horizontal direction so as to intersect with the components, and is arranged so as to extend in the horizontal direction so as to intersect with the filler components forming the rows at both ends in FIG. Both ends of each spacer 66 are fixed to the inner wall of the housing or a frame (not shown), and are fixed to each filler component 60 at an intersection with each filler component 60 by appropriate means such as welding or bonding. The spacer 66 thus configured has a function of maintaining a predetermined interval between the adjacent filler components 60, and prevents the occurrence of a drift due to the movement of raw water between the adjacent filler components 60. To prevent. In this embodiment, the spacers 66 are arranged so as to intersect only the filler components forming the rows at both ends of the filler components 60 forming the rows of the aggregate 64, However, the present invention is not limited to this.
[0067]
In the present embodiment, each of the thread adapters 58 that connects the raw water pipe 56 and the ordered packed body 5 and supplies raw water to the ordered packed body 5 from the raw water pipe 56 has a one-to-one relationship with any one of the packed body components 60. They are formed integrally in a relationship. Therefore, the same number of thread adapters 58 as the number of the filler components 60 constituting the aggregate 64 are provided in each of the filler component aggregates 64. Each adapter 58 is directly connected to the raw water pipe 56 corresponding to each assembly 64 without branching from other adapters and without branching other adapters. Therefore, a plurality of adapters 58 integrated with each of the plurality of filler components 60 constituting the assembly 64 were assembled and bundled inside the lower end of the raw water pipe 56 corresponding to each assembly 64. Inserted and held in shape. FIG. 5 is a cross-sectional view showing a state inside the lower end of the raw water pipe 56 in which the adapters 58 are assembled and inserted. Each adapter 58 is inserted in a state where a certain gap is formed between adjacent adapters and raw water is loosely bundled so that raw water flows down the adapter 58 from the entire periphery of each adapter 58.
[0068]
As the thread-like material forming the thread-like filler component 60 and the thread-like adapter 58, any fiber such as a metal fiber, a vegetable fiber such as a plastic fiber, a carbon fiber, a ceramic fiber, and cotton, and an animal fiber such as wool can be used. . The form of the filamentous material is not particularly limited, such as a wire, a twisted yarn, a monofilament, a wire, etc. Is preferable because it flows through a space between a plurality of yarns or wires constituting a twisted yarn by capillary action, thereby promoting movement of raw water. In the present embodiment, as a preferable example, a wire obtained by twisting two steel wires made by twisting seven steel wires each having a diameter of 0.1 mm is used as one filler component 60 and the adapter 58. be able to.
[0069]
In the above embodiment, a thread-like filler component is used. However, the present invention is not limited to this, and a band-like or plate-like filler component may be used.
[0070]
Referring to FIGS. 1 and 6, clog loosening rod holding member 28 extends on a plane parallel to the surface of filter medium layer 2 so that it can reciprocate above filter tank 3 on the parallel plane. It is arranged. 1 and 6 are views showing a state in which the clogging bar loosening member 28 is reciprocating in the center of the filtration tank 3 during backwashing.
[0071]
A plurality of clogging loosening bars 42 are fixed to the lower surface of the clogging loosening bar holding member 28 so as to extend in the vertical direction. The clog loosening rod 42 is made of a rigid material such as steel, and its tip 42 b is inserted into the surface of the filter medium layer 2.
[0072]
As the filter medium layer 2, a manganese sand having a catalytic function of promoting the oxidation of manganese in the raw water or a filter medium layer in which a colony of iron bacteria is present is used.
[0073]
The flow rate of the raw water in the filtration tank 3, that is, the filtration rate, is desirably the same as that of the rapid filtration, that is, 120 m / d or more.
[0074]
In the filter tank 3, the filter medium layer 2 is supported by a filter medium receiving plate 8 composed of a plurality of wedge wires arranged in parallel. Below the filter medium receiving plate 8 is a lower space 16 from which filtered water is discharged. A filtered water discharge pipe 9 for taking out filtered water is attached to the side wall of the filtration tank 3 facing this space 16. I have.
[0075]
In the lower space 16, one or a plurality of backwash pipes 70 are arranged in a direction orthogonal to the raw water supply branch pipe 54. In the upper part of the backwash pipe 70, a plurality of backwash water jets are opened at predetermined intervals.
[0076]
On both sides 3a and 3b of the filtration tank 3, a backwash water drain gutter 18 is provided such that the upper end edge is located above the surface of the raw water on the filter medium layer. One end 18a of the gutter 18 is closed, and the other end 18b is opened to discharge backwash wastewater to the outside.
[0077]
In the present embodiment, one end of the clogging loosening rod holding member 28 is used as the clogging loosening rod holding member reciprocating mechanism 20 that reciprocates the clogging loosening rod holding member 28 on a plane parallel to the surface of the filter medium layer 2. And a drive unit 23 equipped with an electric motor and a reduction gear for driving the traveling wheels 21 of the traveling box 22 having the traveling wheels 21 at the bottom and a bottom fixed to the other end of the clogging loosening rod holding member 28. A mechanism comprising a traveling plate 25 having traveling wheels 24 and a pair of rails 26 fixed to the frame 3e of the filtration tank 3 so that the traveling wheels 21 and 24 are engaged. By rotating the electric motor of the driving device 23 in one direction, the clogging loosening rod holding member 28 travels in one direction, and by rotating the electric motor in the opposite direction, the clogging loosening rod holding member 28 travels in the opposite direction. I do.
[0078]
The reciprocating movement of the clog loosening rod holding member 28 is not limited to the illustrated mechanism, and other mechanisms such as a mechanism using a feed screw, a chain driving mechanism, and the like may be used.
[0079]
Next, the operation of the manganese removing device according to this embodiment will be described.
At the time of filtering the raw water, the raw water supplied from the iron removing device 100 with the reduced iron content is supplied to the regular packing 5 through the raw water supply main pipe 52, the raw water supply branch pipe 54, the raw water pipe 56, and the adapter 58 of the gas-liquid contact mechanism 4. While operating the blower (not shown), air is supplied from below to above the ordered packing material 5 while supplying it to each packing member component 60. Thereby, gas-liquid contact is performed in the ordered packing body 5, and aeration is performed.
[0080]
Raw water that has been aerated while flowing down the ordered packing material 5 falls onto the filter medium layer 2 of the filter tank 3, and manganese is oxidized in the filter medium layer 2.
[0081]
When the above-mentioned filtering action is continued, manganese oxide and other foreign substances accumulate on the surface of the filter medium layer 2 over time, and the surface of the filter medium layer 2 is covered and blocked by these foreign substances, and the surface layer of the filter medium layer 2 Clogging occurs and the filtering function of the filter medium layer 2 decreases.
[0082]
In this case, with the water surface adjusted to a predetermined level above the surface of the filter medium layer (for example, a level about 10 cm above the surface of the filter medium layer), the clogging loosening rod holding member reciprocating mechanism 20 is operated, and one end of the filter tank 3 is moved. Starting from the position at the time of filtration, the clogging loosening rod holding member 28 is reciprocated in a direction indicated by an arrow in FIG. 6 on a plane parallel to the surface of the filter medium layer 2. As a result, the clogging loosening rod 42 reciprocates while being inserted into the surface layer of the filter medium layer 2, so that the surface layer of the filter medium layer 2 is plowed by the clogging loosening rod 42, and the clogging of the surface of the filter medium layer 2 is reduced. It can be effectively loosened, and the filter medium layer 2 restores its original filtration function. After the clogging of the surface of the filter medium layer 2 is removed in this way, the backwashing pipe 70 is operated to flow backwash water upward from below the filter medium layer 2 through the filter medium receiving plate 8 formed of a plate-like screen. Wash water is discharged to the outside from the backwash water drainage gutter 18.
[0083]
FIG. 8 is a sectional view similar to FIG. 1 showing another embodiment of the present invention, and FIG. 9 is a perspective view similar to FIG. 6 of the same embodiment. In this embodiment, the same components as those in the embodiment of FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.
[0084]
In the embodiment shown in FIG. 8, one or a plurality of backwash tubes 72 are embedded at a predetermined depth in the filter medium layer 2. The buried depth of the backwash tube 72 is a depth sufficient to remove the filter medium layer blockage accumulated on the upper portion of the filter medium layer 2 by backwashing, and the depth of the filter medium layer 2 as thick as possible below the backwash tube 72. The depth is set so that the part exists. The depth is determined in consideration of various factors such as the type and amount of the filter medium layer blockage, the particle size of the sand forming the filter medium layer, the flow rate of the backwash water, and the number of times of backwash during a certain period.
[0085]
In the filter medium layer 2, even when a filter medium layer in which colonies of iron bacteria exist is used, or when manganese sand is used as the filter medium layer, colonies of iron bacteria and other microorganisms are formed as the use period of the filter medium layer 2 becomes longer. This microbial colony is formed not only on the surface layer of the filter medium layer 2 but also from the center to the lower part of the filter medium layer 2, and a considerable amount of manganese is removed even if not as much as the surface layer. The result turned out. That is, it has been found that the manganese removing action by the microorganism is performed at the entire depth position of the filter medium layer. Therefore, by embedding the backwash pipe 72 at such a depth position in the filter medium layer 72, the filter medium layer blockage accumulated on the upper part of the filter medium layer 2 is washed away and removed by the backwash, while the backwash pipe. The backwash does not affect the filter medium layer 2 below the filter medium layer, so that the colonies of iron bacteria and other microorganisms existing in the filter medium layer below the filter medium layer 2 are not destroyed, and the apparatus is operated after the backwash. When the process is restarted, the manganese removing effect of the microorganisms existing in this portion of the filter medium layer 2 is maintained and the manganese removing effect of the entire manganese removing device can be improved.
[0086]
The manganese removal device according to this embodiment stops supply of raw water from the raw water supply pipe 52 during a period when filtered water is not required, that is, when supply of filtered water is stopped, and returns filtered water to the raw water supply main pipe 52 to remove the filter medium layer. Further, there is further provided a filtered water circulation means 80 for circulating the inside of the filter 2.
[0087]
The filtered water circulation means 80 includes a filtered water circulation pipe 74 connecting the filtered water discharge pipe 9 and the raw water supply main pipe 52, a water supply pump 82 connected to the filtered water circulation pipe 74, a filtered water circulation pipe 74, and a filtered water. It is provided at the connecting portion of the take-out pipe 9, supplies filtered water when supplying filtered water, stops water supply to the filtered water circulation pipe 74, stops supply of filtered water when stopped supplying filtered water, and circulates filtered water. A switching valve 76 for returning the raw water to the raw water supply main pipe 52 via a pipe 74, and a connecting portion between the raw water supply main pipe 52 and the filtered water circulation pipe 74. A switching valve 78 is provided which stops the passage of the filtered water from the pipe 74 and stops the passage of the raw water when the supply of the filtered water is stopped, and allows the filtered water from the filtered water circulation pipe 74 to pass.
[0088]
When the supply of the filtered water is stopped, the switching valve 78 is switched to stop the passage of the raw water to the raw water supply main pipe 52 and to allow the passage of the filtered water from the filtered water circulation pipe 74, while the switching valve 76 is set to supply the filtered water. The filtered water is switched to allow the filtered water to pass through the filtered water circulation pipe 74, and the filtered water is supplied from the filtered water discharge pipe 9 through the filtered water circulation pipe 74 by operating the water supply pump 82. After being returned to the pipe 52 and subjected to aeration through the regular packed body 5, it falls into the filter medium layer 2. Therefore, even during a period in which filtered water is unnecessary and the supply of filtered water is stopped, the filtered water is returned to the raw water supply main pipe 52, circulated in the filter medium layer 2 and aeration is continuously performed, so that the filtered water supply is stopped. Dissolved oxygen is sufficiently supplied to the iron bacteria and other microorganisms in the filter medium layer 2 during the operation. As a result, the microorganisms are prevented from being killed or reduced due to lack of oxygen due to the stoppage of the apparatus, and the filter medium layer is restarted when the supply of filtered water is resumed. 2 can be prevented from decreasing.
[0089]
FIG. 10 is a sectional view similar to FIG. 8 showing a modified example of the filtered water circulation means. In this modified example, the filtered water circulation means 90 includes a filtered water discharge pipe 92 and a filtered water circulation outlet 92, a filtered water circulation pipe 94 connecting the filtered water circulation outlet 92 and the raw water supply main pipe 52, A water supply pump 96 connected to the filtered water circulation pipe 94 and a filtered water discharge pipe 9 are provided. The valve 98 is opened when the filtered water is supplied, and closed when the supply of the filtered water is stopped. The filter is provided at a connection portion with the water circulation pipe 94 to allow the passage of raw water when supplying filtered water and stop the passage of filtered water from the filtered water circulation pipe 94. A switching valve 78 is provided as a valve means for passing filtered water from the service pipe 94.
[0090]
In addition, various modifications can be considered as the filtered water circulation means.
[0091]
As a result of an experiment using black sand as the filter medium layer in the apparatus shown in FIG. 8, when the supply of filtered water was stopped after the supply of filtered water was stopped for a day, the case where the filtered water circulation means 80 was not used during the stopped period of supply of filtered water was used. The manganese removal rate of the apparatus was about 50% on average in one week after the supply of filtered water was resumed. The manganese removal rate was 93% on average, demonstrating the usefulness of the filtered water circulation means.
[0092]
【Example】
Example 1
A manganese removal test was performed using the apparatus shown in FIG. 1 using the water whose iron concentration was reduced by treating groundwater collected in Kashiwara-cho, Hyogo using the iron removing apparatus 100 shown in FIG. Was. Manganese sand having a particle size of 2 mm was used as the filter medium layer. The filtration speed was 120 m / day. The manganese concentration, iron concentration and dissolved oxygen concentration of the water to be treated and the purified water after treatment (treated water) were measured once a day at a fixed time. The dissolved oxygen concentration of the treated water was measured by sampling water immediately after aeration by the gas-liquid contact mechanism. Table 1 shows the results.
[0093]

[0094]
As a comparative example, a manganese removal test was performed under the same conditions as in the above experiment, except that treated water was directly injected from the iron removal device 100 into the filtration tank 3 of the device of the present invention without performing aeration by a gas-liquid contact mechanism. Table 2 shows the results.
[0095]

[0096]
From the results in Tables 1 and 2, the manganese concentration of the treated water can be reduced to 0.05 mg / l or less, which is allowed by the water quality standard, according to the example of the present invention in which aeration is performed. According to the example, the manganese concentration of the treated water is 0.164 to 0.248 mg / l, which indicates that the manganese concentration cannot be reduced to the allowable concentration.
[0097]
Example 2
Next, water whose iron content has been reduced by treating groundwater collected in Kashiwara-cho, Hyogo using the iron removal device 100 of FIG. 7 is treated as water to be treated, and is used as aeration means in the device of FIG. A manganese removal test was performed by aeration using a hose instead of using the liquid contact mechanism. That is, aeration was performed by dropping the treated water from the iron removing device 100 from a hose having an inner diameter of 10 mm into the filtration tank 3 of the device of FIG. 1 from a height of 1 m from the water surface at a flow rate of 1 liter / min. As the filter medium layer, black sand having a particle size of 0.6 mm (a filter medium layer in which iron bacterial colonies exist) was used. The filtration speed was 120 m / day. The manganese concentration of the water to be treated and the purified water after treatment (treated water) and the iron concentration of the water to be treated were measured once a day at a fixed time. The dissolved oxygen concentration of the water to be treated was 5 mg / l on average, and the dissolved oxygen concentration of the water immediately after aeration with a hose was 7.2. Table 3 shows the measurement results.
[0098]

[0099]
Example 3
A manganese removal test was performed under the same conditions as in Example 2 except that a filter medium in which iron bacteria Leptothrix was transplanted to filter sand having a particle diameter of 2 mm was used as a filter medium layer. Table 4 shows the test results of the manganese concentration.
[0100]

[0101]
As a comparative example, a manganese removal test was performed under the same conditions as in Example 3 except that ordinary filter sand (particle diameter: 2 mm) into which iron bacteria had not been transplanted was used as the filter medium layer. Table 5 shows the results.
[0102]

[0103]
From the results in Tables 4 and 5, it can be seen that even if aeration is performed, a sufficient manganese-removing effect cannot be obtained in a sand filtration layer in which no colonies of iron bacteria exist.
[0104]
【The invention's effect】
As described above, according to the present invention, the device of the present invention is connected to the subsequent stage of a filtration device that oxidizes and insolubilizes iron in raw water and then captures the same with a filter medium. Since most are trapped, the concentration of iron in the raw water supplied to the present invention is greatly reduced. This eliminates competition in the oxidation of iron and manganese in the filter medium layer, and creates a favorable environment for the oxidation of manganese. The concentration of dissolved oxygen in the raw water is increased by the aeration means, and the oxidation of manganese in the filter medium layer having a function of catalyzing the oxidation of manganese is further promoted. The oxidized manganese deposits on the filter medium layer, and the filtered water is taken out from the filtered water outlet of the filter tank. ADVANTAGE OF THE INVENTION According to the apparatus of this invention, manganese components, such as groundwater, can be highly efficiently removed by quick filtration of 120 m / day or more by a simple and small apparatus without using chemicals, such as an oxidizing agent and a flocculant. it can.
[0105]
When the filter medium layer is a filter medium layer in which colonies of iron bacteria are present, the dissolved oxygen in the raw water increased by aeration acts to promote the growth of iron bacteria.
[0106]
When the filter medium layer is a filter medium layer containing manganese sand as a main component, the dissolved oxygen in the raw water increased by aeration acts to promote catalytic oxidation by manganese sand.
[0107]
In one aspect of the present invention, the aeration means comprises a gas-liquid contact mechanism comprising an ordered packing and an adapter, wherein each packing component extends parallel to each other in a non-contact state with an adjacent packing component and the raw water is supplied by the adapter. Raw water that is directly connected to the supply pipe and flows down from the raw water supply pipe to each packing element moves to the adjacent packing element and flows down without causing non-uniformity in the flow of raw water, so uniform gas-liquid contact Is performed, aeration is performed uniformly, and manganese removal can be performed with the highest efficiency.
[0108]
In one aspect of the present invention, the manganese removing device is a filtered water circulating means for stopping supply of raw water from the raw water supply pipe when the supply of filtered water is stopped, and returning filtered water to the raw water supply pipe to circulate through the filter medium layer. In addition, even during the period in which the filtration water is unnecessary and the supply of the filtration water is stopped, the filtration water is returned to the raw water supply pipe and circulated through the filter medium layer, and the aeration is continuously performed, so that the filtration water supply is performed. During the suspension period, the dissolved oxygen is sufficiently supplied to the iron bacteria and other microorganisms in the filter medium layer, so that the microorganisms are prevented from being killed or reduced due to lack of oxygen, and the manganese removal effect in the filter medium layer is reduced when the supply of the filtered water is resumed. Reduction can be prevented.
[0109]
In one aspect of the present invention, the manganese removing device further includes a backwash tube embedded in the filter medium layer, and the backwash tube removes a filter medium layer blockage accumulated on the upper portion of the filter medium layer by backwashing. The filter media layer is buried at a depth that is large enough to allow a portion of the filter media layer to be as thick as possible below the backwash tube. The backwash does not affect the filter media layer below the backwash tube while it is washed away by, and the colonies of iron bacteria and other microorganisms present in the filter media layer below the filter media layer are destroyed. Therefore, when the operation of the apparatus is resumed after the backwash, the manganese removing effect of the microorganisms present in this portion of the filter medium layer is maintained and the manganese removing effect of the entire manganese removing apparatus can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing one embodiment of a manganese removing device according to the present invention.
FIG. 2 is a perspective view schematically showing a gas-liquid contact mechanism.
FIG. 3 is an enlarged perspective view showing a part of the ordered packing body.
FIG. 4 is a cross-sectional view of a filler component assembly.
FIG. 5 is a cross-sectional view of a raw water pipe.
FIG. 6 is a perspective view schematically showing a filtration tank and a clog loosening rod holding member.
FIG. 7 is a perspective view showing an example of an iron removing device connected to a stage preceding the device of the present invention.
FIG. 8 is a cross-sectional view similar to FIG. 1, schematically illustrating another embodiment of the present invention.
FIG. 9 is a perspective view schematically showing a filtration tank and a clog loosening rod holding member of the embodiment.
FIG. 10 is a sectional view similar to FIG. 8, showing a modified example of the filtered water circulation means.
[Explanation of symbols]
1 Manganese removal equipment
2 Filter media layer
3 Filtration tank
4 Gas-liquid contact mechanism
5 Ordered packing
9 Filtration water outlet
20 Reciprocating mechanism of clog loosening rod holding member
28 Clog loosening rod holding member
42 Clogging loosening stick
58 Adapter
60 Filler components
64 Packing component assembly

Claims (10)

A device that removes manganese in raw water, which is connected to the subsequent stage of a filtration device that oxidizes and insolubilizes iron in raw water and captures it with a filter medium,
A raw water supply pipe arranged at the top of the apparatus;
Aeration means for performing aeration to increase the dissolved oxygen concentration in the raw water,
A filtration tank containing a filter medium layer having a catalytic function of promoting the oxidation of manganese in raw water,
A manganese removing device comprising a filtered water outlet provided in the filtration tank. The manganese removing device according to claim 1, wherein the filter medium layer is a filter medium layer in which a colony of iron bacteria exists. 2. The manganese removing device according to claim 1, wherein the filter medium layer is a filter medium layer containing manganese sand as a main component. The aeration means is a gas-liquid contact mechanism having a flow path forming structure for dividing raw water supplied from a raw water supply pipe disposed at the upper part of the apparatus into a number of flow paths and flowing down the raw water. An ordered packing body, and a plurality of adapters for supplying raw water from the raw water supply pipe to the ordered packing body, wherein the ordered packing body is a packing body component having any one of a plurality of thread-like and band-like shapes. The body components extend vertically in parallel with each other in a non-contact manner with an adjacent filler component, wherein the adapter is integrally formed with the filler component and the adapter branches off from another adapter. 2. The manganese removing device according to claim 1, wherein the manganese removing device is directly connected to the raw water supply pipe without performing. A clogging loosening rod holding member to which a plurality of clogging loosening rods arranged such that the tips are inserted into the surface layer of the filter medium layer are fixed, and the clogging loosening rod holding member is parallel to the surface of the filter medium layer. The manganese removing device according to claim 1, further comprising a mechanism for reciprocating on a flat surface. The apparatus further comprises a filtered water circulating means for stopping the supply of the raw water from the raw water supply pipe when the supply of the filtered water is stopped and returning the filtered water to the raw water supply pipe to circulate through the filter medium layer. The manganese removing device according to any one of 1 to 5. The filtered water circulation means,
A filtered water circulation pipe connecting the filtered water outlet and the raw water supply pipe,
A water supply pump connected to the filtered water circulation pipe,
The filter water supply pipe is provided in the filtrate water circulation pipe, supplies the filtrate water when supplying the filtrate water, stops the water supply to the filtrate water circulation pipe, stops the supply of the filtrate water when the supply of the filtrate water is stopped, and filters the filtrate water. A switching valve for returning to the raw water supply pipe through a water circulation pipe,
The filter is provided in the raw water supply pipe to allow passage of the raw water at the time of supplying the filtered water and to stop the passage of the filtered water from the pipe for circulating the filtered water. 7. A manganese removing device according to claim 6, further comprising a valve means for allowing filtered water from the to pass through. The filtered water circulation means,
A filtered water circulation outlet separate from the filtered water outlet,
A filtered water circulation pipe connecting the filtered water circulation outlet and the raw water supply pipe,
A water supply pump connected to the filtered water circulation pipe,
A valve that is provided in the pipeline on the filtered water outlet side and that opens when filtering water is supplied and closes when filtering water is stopped;
The filter is provided in the raw water supply pipe to allow passage of the raw water at the time of supplying the filtered water and to stop the passage of the filtered water from the pipe for circulating the filtered water. 7. The manganese removing device according to claim 6, further comprising a valve means for allowing filtered water from the to pass through. A backwash tube embedded in the filter medium layer, wherein the backwash tube has a depth sufficient to remove the filter medium layer blockage accumulated on the upper portion of the filter medium layer by backwashing, and The manganese removing device according to any one of claims 1 to 8, wherein the manganese removing device is buried at a depth such that a portion of the filter medium layer as thick as possible exists below the pipe. A method of removing manganese in raw water after capturing iron in raw water with a filter medium,
A step of increasing the concentration of dissolved oxygen in the raw water supplied from the raw water supply pipe by aeration,
A step of passing raw water through a filter medium layer having a catalytic function of promoting manganese oxidation,
Removing the filtered water that has passed through the filter medium layer,
When the supply of filtered water is stopped, the supply of raw water from the raw water supply pipe is stopped, the filtered water is returned to the raw water supply pipe, circulated through the filter medium layer, and the aeration is continuously performed, thereby dissolving dissolved oxygen in the filtered water. Maintaining the concentration at a predetermined level.

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