JPS6055198B2 - Wastewater treatment and denitrification method - Google Patents

Description

【発明の詳細な説明】 本発明は汚水の処理兼脱窒方法に関する。[Detailed description of the invention] The present invention relates to a method for treating and denitrifying wastewater.

従来行なわれている活性汚泥法や散水枦床法のような汚
水の生物的処理法では汚水の総窒素の除去率は非常に低
く、他の高級処理法といわれていｊる濾過、凝集、活性
炭吸着法などでも汚水中の燐の除去は可能でも総窒素の
除去は非常に困難である。Conventional biological treatment methods for wastewater, such as the activated sludge method and the sprinkling bed method, have a very low removal rate of total nitrogen from wastewater. Although it is possible to remove phosphorus from wastewater using adsorption methods, it is extremely difficult to remove total nitrogen.

僅かに実施可能な汚水の脱窒方法として土壌浄化法が期
待されるが、それもアンモニア性窒素を硝酸にまで酸化
するだけで、総窒素の除去は期待できないのが実状であ
る。The soil purification method is expected to be a slightly viable denitrification method for wastewater, but the reality is that it only oxidizes ammonia nitrogen to nitric acid and cannot be expected to remove the total nitrogen.

この土壌浄化法の改良法としてトレンチ溝方式に毛管サ
イフオン浸潤法を追加した新らしい汚水の処理方法並に
装置が本発明者新見等によつて発明（特許第５４２４４
？，第５８２６１汚，第５９０９２７号）されているが
、これらの発明も汚水の総窒素を除去するまでには到ら
ず、もつぱら有機物の分解、大腸菌などの殺菌を目標と
するものである。また特許第６１０７８３号の人工浄化
砂も汚水処理における硝化能を促進するだけにとどまり
、汚水の総窒素を除去することは可能でない。このよう
に従来の汚水処理技術では汚水の総窒素の除去が低いと
いう欠点があつたが、この欠点を解決したのが本発明で
ある。As an improvement to this soil purification method, a new sewage treatment method and device were invented by Niimi et al. (Patent No. 54244), which added a capillary siphon infiltration method to the trench method.
? , No. 58261, No. 590927), but these inventions do not go so far as to remove the total nitrogen from sewage, but only aim at decomposing organic matter and sterilizing Escherichia coli. Moreover, the artificial purifying sand of Patent No. 610783 only promotes nitrification ability in wastewater treatment, and is not capable of removing total nitrogen from wastewater. As described above, conventional sewage treatment techniques had the disadvantage that removal of total nitrogen from sewage was low, but the present invention solves this disadvantage.

すなわち、本発明は不透水性の槽を土中に埋設し、その
槽の内部からその上端を越えて堆積された層状をなすよ
うな毛管サイフオン運動を促進せしめる材料の層を設け
、また上記槽の底面から土壌表面に到る間に有孔管を設
け、この有孔管を汚水導入管に連結し、有孔管より汚水
を汚水面が上記槽の上面より底面に到る適当な位置にあ
るように供給したのち、汚水の供給をとめ、上記毛管サ
イフオン運動を促進せしめる材料の層における毛管サイ
フオン運動により汚水が上記槽外に排出されて汚水面が
適当に下つたとき再び汚水の供給を上記の如く行なつた
のち、再び汚水の供給をとめ毛管サイフオン運動により
汚水を上記槽外に排出させるというように汚水の供給と
排出を繰り返すことを特徴とする汚水の処理兼脱窒方法
である。That is, the present invention involves burying a water-impermeable tank in the ground, providing a layer of material that promotes capillary siphon movement in a layered manner deposited from the inside of the tank over its upper end, and A perforated pipe is provided between the bottom of the tank and the soil surface, and this perforated pipe is connected to a sewage introduction pipe, and the sewage is transferred from the perforated pipe to an appropriate position where the sewage surface reaches the bottom from the top of the tank. After supplying the sewage to a certain level, the supply of sewage is stopped, and when the sewage is discharged out of the tank due to the capillary siphon movement in the layer of material that promotes the capillary siphon movement and the sewage level has fallen appropriately, the supply of sewage is restarted. After carrying out the above-mentioned process, the supply of wastewater is stopped again and the wastewater is discharged outside the tank by capillary siphon movement.This method is characterized by repeating the supply and discharge of wastewater. .

以下、本発明の構成および効果について詳細に説明する
。本発明においては不透水性の槽を土中に埋設する。Hereinafter, the configuration and effects of the present invention will be explained in detail. In the present invention, an impermeable tank is buried in the soil.

槽の大きさは処理される汚水の水質によつて決められる
が、通常巾は３０〜１００ｃｍ位、長さは１ｍ以上、好
ましくは１ＷＬ〜５０ＴｒＩ，位、深さは１０〜１００
ｃｍ位、好ましくは３０〜１（１）ｄ位の槽が適当であ
る。例えば台所や浴湯からの排水のような窒素濃度の低
い汚水の処理には巾３０ｃｍ１長さ１０〜１００ｍ１深
さ１０〜（イ）ｄ１好ましくは３０〜印ｄの槽が適当で
あり、また例えば家畜のし尿のような窒素濃度の高い汚
水を処理する場合には、沈澱槽や貯溜槽と組合わせ巾６
０〜１００ｃｍ１長さ１０〜１００７ＴＬ１深さ１００
Ｃ７１となるべく細長い構造の槽が好ましい。槽の材料
としては、例えばコンクリート、ゴム膜、合成樹脂膜（
例えばポリエチレン膜など）などが用いられ、コンクリ
ート槽の場合は現地打またはプレハブ組立で埋設が行な
われる。槽の埋設は槽の上端が土壌表面から１０〜１０
０ｃｍの位置、好ましくは２０〜５０Ｃ７７！の位置に
あるように埋設するのがよい。The size of the tank is determined by the quality of the wastewater to be treated, but usually the width is about 30 to 100 cm, the length is 1 m or more, preferably 1 WL to 50 TrI, and the depth is 10 to 100 cm.
A tank of about 30 to 1(1) cm in size is suitable. For example, a tank with a width of 30 cm, a length of 10 to 100 m, a depth of 10 to (a) d, and preferably 30 to d is suitable for treating sewage with a low nitrogen concentration, such as wastewater from kitchens and baths. When treating wastewater with a high nitrogen concentration such as livestock excrement, it is necessary to use a sedimentation tank or storage tank with a width of 6.
0~100cm1 length 10~1007TL1 depth 100
A tank with an elongated structure such as C71 is preferable. Examples of tank materials include concrete, rubber membrane, synthetic resin membrane (
For example, polyethylene membranes, etc.) are used, and in the case of concrete tanks, burying is done by pouring on-site or by prefabricated assembly. When burying the tank, the upper end of the tank should be 10 to 10 meters below the soil surface.
0cm position, preferably 20-50C77! It is best to bury it so that it is located at

つぎに、上記槽の内部からその上端を越えて堆積された
層状をなすような毛管サイフオン運動を促進せしめる材
料の層を設ける。A layer of material is then provided which promotes capillary siphon movement in a layered manner deposited from the interior of the vessel over its top.

この材料としては、例えばパーライト、泥炭、クリンカ
ー（火力発電所で生産される石炭灰）、火山礫、レンガ
砂などの人工浄化砂、連通空隙を有するスポンジ性樹脂
、団粒構造を有する土壌、珊瑚礁の石粒、軽石粒、粗砂
、砂利からなる群から選ばれる１つまたは２以上が用い
られる。Examples of this material include perlite, peat, clinker (coal ash produced at thermal power plants), volcanic lapilli, artificially purified sand such as brick sand, spongy resin with continuous voids, soil with an aggregate structure, and coral reefs. One or more selected from the group consisting of stone grains, pumice grains, coarse sand, and gravel are used.

この毛管サイフオン運動を促進せしめる材料の層は、上
記の土中に埋設した槽の内部からその上端を越えて層状
に堆積される。この場合、槽の上端を越える程度は槽の
上端より５ｃｍ以上、好ましくは５〜２０ｃｍであるの
がよい。つぎに上記槽の底面から土壌表面に到る間、好
適には上記毛管サイフオン運動を促進せしめる材料の層
中に有孔管を設け、この有孔管を汚水導入管に連結する
。A layer of material that promotes capillary siphon movement is deposited in layers from the interior of the buried tank above the top thereof. In this case, the amount exceeding the upper end of the tank is preferably 5 cm or more, preferably 5 to 20 cm from the upper end of the tank. A perforated pipe is then provided between the bottom of the tank and the soil surface, preferably in the layer of material that promotes capillary siphon movement, and this perforated pipe is connected to the sewage inlet pipe.

有孔管は管の全周辺に沢山の小孔が開口したもので、通
常農業用の暗渠排水管に用いるために開発されたもの（
管径は直径５０Ｔｗｔと６５順の２種類）を便利に使用
することができるが、これに限られることはない。Perforated pipes have many small holes around the entire circumference of the pipe, and were usually developed for use in agricultural culvert drainage pipes (
Two types of pipe diameters, 50 Twt and 65 Twt, can be conveniently used, but the pipe diameter is not limited to this.

そして有孔管の材質としてはコルゲート管または塩ビ管
が適当である。つぎに本発明で処理される汚水としては
、例えば台所や浴場の廃水やし尿のような生活廃水、家
畜の糞尿のような家畜廃水、重金属を含まない工業廃水
（例えば食品工場からの廃水）などが挙げられる。Corrugated pipe or PVC pipe is suitable as the material for the perforated pipe. Next, the wastewater to be treated in the present invention includes, for example, domestic wastewater such as kitchen and bathroom wastewater and night soil, livestock wastewater such as livestock manure, and industrial wastewater that does not contain heavy metals (e.g. wastewater from food factories). can be mentioned.

なお汚水には必要に応じて炭素源、例えばブドウ糖など
の糖類、時によつてはメタノールなどを添加して有孔管
から供給すると、脱窒を促進する効果があるのて好まし
い。本発明ではこれら汚水を例えばポンプにより汚水導
入管に流し、汚水導入管に連結する有孔管より排出させ
る。It is preferable to add a carbon source, for example, sugars such as glucose, or sometimes methanol, to the wastewater as necessary and supply it through a perforated pipe, since this has the effect of promoting denitrification. In the present invention, the wastewater is passed through a wastewater introduction pipe using, for example, a pump, and is discharged from a perforated pipe connected to the wastewater introduction pipe.

この有孔管から排出された汚水は上記槽が不透水性であ
るので、槽内に湛水し、槽の上面より底面に到る適当位
置に汚水面を形成する。そこで汚水の供給をとめると、
上記毛管サイフオン運動を促進せしめる材料の層におけ
る毛管サイフオン運動により汚水は槽外に排出し、一部
は土壌面からの蒸発および植物根からの蒸散となるが、
その他は土壌中に浸潤し重力水となつて地下水面に到る
。したがつて上記槽内の汚水面は汚水の供給の停止によ
り下がり、場合によつては槽の底面近くまで下がる。こ
こで再び上記のようにして有孔管より汚水を供給すると
槽内の汚水面は上がり、汚水面が適当に上がつたところ
で汚水の供給を停止すると槽内の汚水面は再び下がる。
このように汚水の供給が間断的であると、槽内の汚水面
は高い位置から低い位置の間を上下する。この上下の高
さは、毛管サイフオン運動を促進せしめる材料の種類、
性質および毛管サイフオン運動能力、汚水の量、土壌の
浸潤能などで定まる値であるが、通常１日に２０ｗ！ｎ
〜３００？位である。また１日に何回汚水面の水位を変
動させるかについては汚水の供給方式によつて異なるの
で一様でないが、汚水の供給および停止による汚水面の
最高水位と最低水位を予め設計し、最高水位になれは汚
水を停止し、最低水位になれば汚水の供給を始めるとい
うようにするのがよい。ところで土壌中において汚水の
総窒素の除去を完全にするためには、硝化と脱窒の双方
を実施するより他はない。Since the tank is impermeable, the wastewater discharged from the perforated pipe floods the tank and forms a wastewater surface at an appropriate position from the top to the bottom of the tank. When the sewage supply is stopped,
Due to capillary siphon movement in the layer of material that promotes capillary siphon movement, wastewater is discharged outside the tank, and some of it evaporates from the soil surface and transpires from plant roots.
Others infiltrate into the soil and reach the groundwater table as gravity water. Therefore, the sewage level in the tank drops when the supply of sewage is stopped, and in some cases, it drops to near the bottom of the tank. Here, when sewage is again supplied from the perforated pipe as described above, the sewage level in the tank rises, and when the sewage level rises to an appropriate level, when the supply of sewage is stopped, the sewage level in the tank falls again.
If the supply of sewage water is intermittent in this way, the sewage level in the tank fluctuates between a high position and a low position. This vertical height depends on the type of material that promotes capillary siphon movement,
The value is determined by the nature, capillary siphon movement ability, amount of sewage, soil infiltration ability, etc., but normally 20W per day! n
~300? It is the rank. In addition, the number of times a day the water level of the sewage surface is changed is not uniform because it differs depending on the sewage supply method, but the highest and lowest water levels of the sewage surface due to supply and stop of sewage are designed in advance, and the maximum It is best to stop the sewage supply when the water level reaches the lowest level, and start sewage supply when the water level reaches the lowest level. By the way, in order to completely remove the total nitrogen from wastewater in the soil, there is no choice but to carry out both nitrification and denitrification.

そして土壌中における硝化は好気状態における好気性微
生物により、一方脱窒は嫌気状態における嫌気性微生物
により行なわれる。そこで上記したように、有孔管より
汚水を供給して上記槽内に湛水させ汚水面が上記槽内の
適当位置にあるようにして汚水の供給を停止すると、汚
水中に溶存酸素がある限りは槽内の汚水面以下は好気状
態となり好気性微生物による硝化が行なわれるが、溶存
酸素が好気性微生物によつて消費され槽内の汚水面下が
嫌気状態になると嫌気性微生物による脱窒が進行し、こ
れは次の汚水が供給されるまでつづき、その間に硝化お
よび脱窒された汚水は上記したように毛管サイフオン運
動を促進せしめる材料の層における毛管サイフオン運動
により槽外に排出され、汚水面は下がる。Nitrification in soil is carried out by aerobic microorganisms under aerobic conditions, while denitrification is carried out by anaerobic microorganisms under anaerobic conditions. Therefore, as mentioned above, when sewage is supplied through a perforated pipe, the tank is filled with water, and the sewage surface is at an appropriate position in the tank, and the supply of sewage is stopped, there is dissolved oxygen in the sewage. For a long time, the area below the sewage surface in the tank will be in an aerobic state and nitrification will occur by aerobic microorganisms, but if the dissolved oxygen is consumed by aerobic microorganisms and the area below the sewage surface in the tank becomes anaerobic, desorption by anaerobic microorganisms will occur. Nitrification progresses and this continues until the next supply of wastewater, during which time the nitrified and denitrified wastewater is discharged out of the tank by capillary siphon movement in the layer of material that promotes capillary siphon movement as described above. , the sewage level will fall.

汚水面がある程度まで下がつたところで次の汚水が供給
されて汚水面が上がると、汚水中の溶存酸素により槽内
の汚水面下は好気状態になり好気性微生物による硝化が
行なわれるが、溶存酸素が好気性微生物によつて消費さ
れ、槽内の汚水面下が嫌気状態になると嫌気性微生物に
よる脱窒が進行し、これは次の汚水が供給されるまでつ
づき、その間に硝化および脱窒された汚水は上記したよ
うにして槽外に排出される。このように硝化および脱窒
され槽外に排出された汚水はそこで再び土壌微生物によ
り地表近くが好気状態にある場合には好気性微生物によ
り硝化され、また嫌気状態にある楊合には嫌気性微生物
により脱窒され、一部は土壌面からの蒸発および植物根
からの蒸散となるが、その他は土壌中に浸潤し重力水と
なつて地下水面に到る。Once the sewage level has fallen to a certain level, the next sewage is supplied and the sewage level rises.The area below the sewage surface in the tank becomes aerobic due to the dissolved oxygen in the sewage, and nitrification is carried out by aerobic microorganisms. When dissolved oxygen is consumed by aerobic microorganisms and the surface of the wastewater in the tank becomes anaerobic, denitrification by the anaerobic microorganisms proceeds until the next wastewater is supplied, during which time nitrification and denitrification occur. The nitrified wastewater is discharged outside the tank as described above. The wastewater that has been nitrified and denitrified and discharged outside the tank is nitrified by soil microorganisms again by aerobic microorganisms when near the ground surface is in an aerobic state, and nitrified by aerobic microorganisms when the ground is in an anaerobic state. It is denitrified by microorganisms, and some of it evaporates from the soil surface and transpires from plant roots, but the rest infiltrates into the soil and reaches the groundwater table as gravity water.

この地下水は硝化および脱窒された地下水である。つぎ
に本発明をなお一層よく理解できるように、図面につい
て説明する。This groundwater is nitrified and denitrified groundwater. In order to further understand the invention, reference will now be made to the drawings.

第１図は土中に埋設した１つの不透水性の槽を縦断し正
面から見た図であり、第２図は同じ槽を縦断し側面から
見た図であり、第３図は土中に埋設した２つの不透水性
の槽を縦断し正面から見た図である。図中、１は土中に
埋設した不透水性の槽であり、２はその槽１の内部から
のその上端を越えて堆積された毛管サイフオン運動を促
進せしめる材料の層（この図面では下部が火山砂、上部
が砂利となつている）であり、３は必要に応じて該層２
と表面土壌４との境界に設けたアミであり、５は汚水導
入管６に連結している有孔管である。アミ３は表面土壌
４が毛管サイフオン運動を促進せしめる材料の層２中に
、また有孔管５中に落下しな”いように設けられるもの
で、表面土壌４の粒子の径と層２の粒子の径とが接近し
ている場合にはアミは必要としない。汚水を汚水導入管
６に流入し有孔管５より排出させると、汚水は槽１内に
湛水し槽１の上面より門底面に到る適当位置に汚水面を
形成する。そして汚水の供給をとめたときの汚水面即ち
最高汚水面が７である。汚水の供給停止後、層２におけ
る毛管サイフオン運動により汚水は槽１外に排出され汚
水面が最低汚水面８に下がつたとき、汚水の供ノ給を行
なつて汚水面を７まで上げる。このようにして有孔管５
よりの汚水の供給および停止により汚水面は７と８の間
を上下し、その間に上述した硝化および脱窒が行われる
のである。９は槽１外に排水された汚水の経路を示すも
ので、一部は土壌表面１０からの蒸発および植物１１の
根からの蒸散となるが、その他は土壌中に浸潤し重力水
となつて地下水面に到る。Figure 1 is a vertical cross-sectional view of an impermeable tank buried in the soil and viewed from the front, Figure 2 is a vertical cross-sectional view of the same tank and viewed from the side, and Figure 3 is a vertical view of the same tank buried in the soil. Fig. 2 is a longitudinal cross-sectional view of two impermeable tanks buried in the tank, seen from the front. In the figure, 1 is an impermeable tank buried in the soil, and 2 is a layer of material that promotes capillary siphon movement deposited from the inside of tank 1 over its upper end (in this drawing, the lower part is (volcanic sand, the upper part is gravel), and 3 is the layer 2 as necessary.
and surface soil 4, and 5 is a perforated pipe connected to a wastewater introduction pipe 6. The sill 3 is provided to prevent the surface soil 4 from falling into the layer 2 of the material that promotes capillary siphon movement and into the perforated tube 5. If the diameters of the particles are close to each other, no mesh is required.When wastewater flows into the wastewater introduction pipe 6 and is discharged from the perforated pipe 5, the wastewater floods into the tank 1 and flows from the top of the tank 1. A sewage surface is formed at an appropriate position reaching the bottom surface of the gate.The sewage surface when the sewage supply is stopped, that is, the highest sewage surface is 7.After the sewage supply is stopped, the sewage flows into the tank due to capillary siphon movement in layer 2. 1 When the sewage is discharged outside and the sewage level drops to the lowest sewage level 8, sewage is supplied to raise the sewage level to 7. In this way, the perforated pipe 5
The sewage level rises and falls between 7 and 8 as the sewage water is supplied and stopped, and the above-mentioned nitrification and denitrification occur during this period. 9 shows the route of wastewater drained outside the tank 1. Some of it evaporates from the soil surface 10 and transpires from the roots of plants 11, but the rest infiltrates into the soil and becomes gravity water. reaches the groundwater table.

第３図は傾斜地（例えば道路のり面、山林など）の土壌
に不透水性の槽１を２つ落差を設けて埋設した場合を示
すもので、このようにすると２段目の槽１においては有
孔管５よりの汚水が前段の槽１の処理水によつて稀釈さ
れ、これが硝化、脱窒されて水処理効果は非常に増加す
る。Figure 3 shows a case where two impermeable tanks 1 are buried in the soil of a slope (for example, a road slope, a mountain forest, etc.) with a head difference. The wastewater from the perforated pipe 5 is diluted by the treated water from the tank 1 in the previous stage, and this is nitrified and denitrified, greatly increasing the water treatment effect.

なお第３図中、１２は母岩または自然の不透水層、１３
は地下水の移動方向、１４は浸出水、１５は土止め工を
示す。通常土壌中の硝化、脱窒は１イ当り１Ｅ１＋こ５
〜５０′前後が可能で、本発明による硝化および脱窒に
よる汚水の総窒素の除去率は非常に高いものである。In Figure 3, 12 is the host rock or natural impermeable layer, 13
14 indicates the moving direction of groundwater, 14 indicates leachate, and 15 indicates the earth retaining structure. Normally, nitrification and denitrification in soil are 1E1 + 5 per liter.
~50' is possible, and the removal rate of total nitrogen from wastewater by nitrification and denitrification according to the present invention is extremely high.

そして本発明によると、汚水中の窒素の除去以外に例え
ば有機物は９５％、浮遊物質は部％、大腸菌は９９％、
動植物油は部％、リンは９９％の除去率を示すことがで
きる。なお、地表面に植物を植えたり、表面土壌に土壌
動物の活動を加えると、汚水の処理効果は更に増加する
。According to the present invention, in addition to removing nitrogen in wastewater, for example, organic matter is 95%, suspended solids are 99%, Escherichia coli is 99%,
It is possible to show a removal rate of 1% for animal and vegetable oils and 99% for phosphorus. Furthermore, if plants are planted on the ground surface or soil animal activity is added to the surface soil, the wastewater treatment effect will further increase.

本発明により処理され脱窒された処理水は地下水域に貯
溜され地下水汚染を招来することなく再び有効に利用す
ることができる。The treated water treated and denitrified according to the present invention is stored in an underground water body and can be effectively used again without contaminating the ground water.

つぎに本発明の実施例を示すが、本発明はこれにより制
限されるものではない。Next, examples of the present invention will be shown, but the present invention is not limited thereto.

実施例 コンクリートを材料とする不透水性の巾３０ｃ１ｎ、深
さ０ａ１長さ１０ｍの槽を、一般の腐植まじりの．関東
ローム土壌中に埋設し、槽の上端を地表より２０Ｃｒ１
，下方に位置させる。Example A water-impermeable tank made of concrete with a width of 30cm, a depth of 0a, and a length of 10m was filled with ordinary humus. Buried in Kanto loam soil, with the upper end of the tank raised 20Cr1 from the ground surface.
, located below.

平均直径０．６顛の火山砂を槽の底面よりるｄの高さに
まで満たし、この砂層の上辺中央に槽の長辺に平行に径
５０Ｔｎの孔あき塩ビ管を設置し、その一方の末端を汚
水導入管に一連結する。この火山砂の層の上方１５ＣＩ
！ｔまでに砂山を山形状に積み、さらにその砂利の上面
にアミ目の間隔が２〜３ＴＩｒ１ｎになつている合成樹
脂製アミで土壌中で分解しないものを全面にかぶせる。
つぎに水洗便所からの排水（総窒素量ケルダール法で１
００ｐｐｍ）の汚水導入管および穴あき塩ビ管を通して
の上記槽への供給を、汚水導入管と上記槽との間に設置
したポンプにより３時間おきに開始する。即ち汚水導入
管から孔あき塩ビ管を通しての上記槽への排水の供給を
数分間行ない、ついで３時間排水の供給をとめ、排水の
供給停止３″時間後に再びポンプを数分動かして排水の
供給を行なうようにする。このようにすると汚水面は上
記槽の上端を越えることなく、この間の汚水面の水位変
動の高さはＷＯ前後となる。そして上記槽の上辺より水
平に約２ＴｒＬ離れたところ迄の全部の浸潤水を採水し
測定できるように実験的に集水装置を設け、毛管運動に
より上記槽外に排出される処理水を集水する。The tank was filled with volcanic sand with an average diameter of 0.6 square meters to a height of d from the bottom of the tank, and a perforated PVC pipe with a diameter of 50Tn was installed parallel to the long side of the tank at the center of the upper side of this sand layer, and one of the Connect the end to the wastewater inlet pipe. 15 CI above this layer of volcanic sand
! By t, sand piles are piled up in a mountain shape, and the upper surface of the gravel is further covered with a synthetic resin filament that does not decompose in the soil and has a filament interval of 2 to 3 TIr1n.
Next, drain water from the flush toilet (total nitrogen content 1 by Kjeldahl method)
00 ppm) to the tank through the sewage inlet pipe and the perforated PVC pipe is started every 3 hours by a pump installed between the sewage inlet pipe and the tank. That is, wastewater is supplied from the wastewater inlet pipe to the above tank through the perforated PVC pipe for several minutes, then the supply of wastewater is stopped for 3 hours, and after 3" hours after the supply of wastewater has stopped, the pump is operated again for several minutes to supply wastewater. In this way, the sewage surface will not exceed the top of the tank, and the height of the water level fluctuation during this period will be around WO.Then, the sewage surface will not exceed the top of the tank, and the height of the water level fluctuation during this period will be around WO. A water collection device was installed experimentally so that all the infiltrated water up to the point could be sampled and measured, and the treated water discharged outside the tank by capillary movement was collected.

この集水した水の総窒素量をケルダール法で測定すると
１０ｐｐｍ以下であることが認められた。When the total nitrogen content of this collected water was measured using the Kjeldahl method, it was found to be 10 ppm or less.

このことから、本実施例によると、総窒素量１００ｐｐ
ｍの水洗便所よりの排水が１０ｐｐｍ以下に脱窒された
ことがわかる。From this, according to this example, the total nitrogen amount is 100 pp.
It can be seen that the wastewater from the flush toilets of 300 m was denitrified to 10 ppm or less.

【図面の簡単な説明】[Brief explanation of the drawing]

図面は本発明の説明図であり、第１図は土中に埋設した
１つの不透水性の槽を縦断し正面から見た図であり、第
２図は同じ槽を縦断し側面から見た図であり、第３図は
土中に埋設した２つの不透水性の槽を縦断し正面から見
た図である。 １・・・・・・不透水性の槽、２・・・・・・毛管サィ
フオン運動を促進せしめる材料の層、３・・・・・・ア
ミ、４・・・・・・表面土壌、５・・・・・・有孔管、
６・・・・・・汚水導入管、７・・・・・・最高汚水面
、８・・・・・・最低汚水面、９・・・・・・槽１外に
排出された汚水の経路、１０・・・・・・土壌表面、１
１・・・・・・植物、１２・・・・・・母岩または自然
の不透水層、１３・・・・・・地下水の移動方向、１４
・・・・・・浸出水、１５・・・・・・土止め工。The drawings are explanatory diagrams of the present invention; Figure 1 is a vertical cross-sectional view of one impermeable tank buried in the soil and seen from the front, and Figure 2 is a vertical cross-sectional view of the same tank seen from the side. FIG. 3 is a longitudinal cross-sectional view of two impermeable tanks buried in the soil and viewed from the front. 1... Impermeable tank, 2... Layer of material that promotes capillary siphon movement, 3... Ame, 4... Surface soil, 5 ...perforated pipe,
6... Sewage introduction pipe, 7... Maximum sewage level, 8... Minimum sewage level, 9... Route of sewage discharged outside tank 1. , 10... Soil surface, 1
1... Plants, 12... Host rock or natural impermeable layer, 13... Direction of movement of groundwater, 14
...Leachate, 15...Earth retaining work.

Claims (1)

【特許請求の範囲】 １ 不透水性の槽を土中に埋設し、その槽の内部からそ
の上端を越えて堆積された層状をなすような毛管サイフ
オン運動を促進せしめる材料の層を設け、また上記槽の
底面から土壌表面に到る間に有孔管を設け、この有孔管
を汚水導入管に連結し、有孔管より汚水を汚水面が上記
槽の上面より底面に到る適当位置にあるように供給した
のち、汚水の供給をとめ、上記毛管サイフオン運動を促
進せしめる材料の層における毛管サイフオン運動により
汚水が上記槽外に排出されて汚水面が適当に下つたとき
再び汚水の供給を上記の如く行なつたのち、再び汚水の
供給をとめ毛管サイフオン運動により汚水を上記槽外に
排出させるというように汚水の供給と排出を繰り返すこ
とを特徴とする汚水の処理兼脱窒方法。 ２ 槽の上端が土壌表面から１０〜１００ｃｍの位置、
好ましくは２０〜５０ｃｍの位置にあるように不透水性
の槽を埋設する特許請求の範囲第１項記載の汚水の処理
兼脱窒方法。 ３ 毛管サイフオン運動を促進せしめる材料の層を、そ
の上面が槽の上端より５ｃｍ以上上の位置にあるように
設ける特許請求の範囲第１項記載の汚水の処理兼脱窒方
法。 ４ 毛管サイフオン運動を促進せしめる材料の層を、そ
の上面が槽の上端より５〜２０ｃｍ上の位置にあるよう
に設ける特許請求の範囲第３項記載の汚水の処理兼脱窒
方法。 ５ 毛管サイフオン運動を促進せしめる材料としてパー
ライト、泥炭、クリンカー、火山礫、レンガ砂などの人
工浄化砂、連通空隙を有するスポンジ性樹脂、団粒構造
を有する土壌、珊瑚礁の石粒、軽石粒、粗砂、砂利から
なる群から選ばれる１つまたは２以上が用いられる特許
請求の範囲第１項記載の汚水の処理兼脱窒方法。 ６ 汚水として炭素源を添加した汚水を有孔管より供給
する特許請求の範囲第１項記載の汚水の処理兼脱窒方法
。[Claims] 1. An impermeable tank is buried in the soil, and a layer of material that promotes capillary siphon movement is deposited from the inside of the tank over its upper end, and A perforated pipe is provided between the bottom of the tank and the soil surface, and this perforated pipe is connected to a sewage introduction pipe, and the sewage is delivered from the perforated pipe to an appropriate position where the sewage surface reaches the bottom from the top of the tank. After the sewage is supplied as shown in , the supply of sewage is stopped, and when the sewage is discharged out of the tank by the capillary siphon movement in the layer of material that promotes the capillary siphon movement, and the sewage level has fallen appropriately, the sewage is supplied again. A method for treating and denitrifying sewage characterized by repeating the supply and discharge of the sewage by stopping the supply of the sewage again and discharging the sewage to the outside of the tank by capillary siphon movement. 2. The top of the tank is 10 to 100 cm from the soil surface,
The method for treating and denitrifying wastewater according to claim 1, wherein a water-impermeable tank is buried preferably at a distance of 20 to 50 cm. 3. The wastewater treatment and denitrification method according to claim 1, wherein the layer of material that promotes capillary siphon movement is provided so that its upper surface is located at least 5 cm above the upper end of the tank. 4. The wastewater treatment and denitrification method according to claim 3, wherein the layer of material that promotes capillary siphon movement is provided so that its upper surface is located 5 to 20 cm above the upper end of the tank. 5. Materials that promote capillary siphon movement include perlite, peat, clinker, volcanic lapilli, artificially purified sand such as brick sand, sponge resin with continuous voids, soil with aggregate structure, coral reef stone grains, pumice grains, and coarse grains. The wastewater treatment and denitrification method according to claim 1, wherein one or more selected from the group consisting of sand and gravel are used. 6. The wastewater treatment and denitrification method according to claim 1, wherein wastewater to which a carbon source has been added is supplied as wastewater through a perforated pipe.