【０００１】
【発明の属する技術分野】
本発明は、悪臭成分の生物学的脱臭に係り、特に下水処理場、し尿処理場、各種工場等から発生する悪臭ガスを、生物学的に脱臭する脱臭用充填材とそれを用いる脱臭方法及び装置に関する。
【０００２】
【従来の技術】
【特許文献１】特公平６−９１９３４号公報
【特許文献２】特開平６−２９６８２１号公報
生物学的に悪臭ガス中の悪臭成分を分解除去する脱臭方法として、微生物を含有する汚泥を付着させた充填層と悪臭ガスを接触させて脱臭する充填塔式生物脱臭方法や悪臭ガスと微生物を含有する活性汚泥懸濁液と接触させるスクラバー法や悪臭ガスを活性汚泥懸濁液に吹き込む活性汚泥脱臭法が実用化されている。
なかでも、充填層の圧力損失が少なく、悪臭ガスとの気液接触が良好なために脱臭性能が高く、大量の悪臭ガスをコンパクトな脱臭装置で脱臭できる充填塔式生物脱臭方法が広く普及している。
充填塔式生物脱臭装置には、充填層を縦方向に配置した縦型（特公平６−９１９３４号公報）と充填層を建屋の床と水平になる横型（特開平６−２９６８２１号公報）がある。
【０００３】
図１に縦型生物脱臭装置の概略図を、図２に横型生物脱臭装置の概略図を示す。縦型生物脱臭装置は、充填層下部から悪臭ガス６が流入し、充填層３を経由して充填層上部から処理ガス７が排出される。充填層上部から循環液８や補給水９が散水され、充填層３に棲息する微生物への水分補給と、臭気成分の分解生成物である硫酸イオンなどが、充填層から洗浄排出される。また、悪臭ガスが充填層上部から流入し、充填層を経由して、充填層下部から処理ガスが排出される方式もある。横型生物脱臭装置は、充填層側面から悪臭ガスが流入し、充填層を経由して、流入と反対側の充填層側面から、処理ガスが排出される。充填層上部から散水される。
従来より、いずれの型式でも充填塔式生物脱臭装置の脱臭性能を決定するのは、個々の充填材の形状と粒径である。
従来の充填塔式生物脱臭装置には、プラスチック成形物や磁器やセラミックスや活性炭やＰＶＡ粒状造粒物などの粒状、破砕状、鱗片状、繊維状の最大直径２０ｍｍまでの充填材が使用され、これら充填材は、充填塔式生物脱臭装置の充填層空間不規則に充填されている。
【０００４】
従来の技術では、以下の問題がある。
（１）粒状、破砕状、鱗片状、繊維状の充填材は、これら充填して形成される充填層が、だんだんと圧密して、充填層の圧力損失が増加し、処理ガス量の低下や悪臭ガスの偏流れを起こして脱臭性能が低下する。
（２）粒状、破砕状、鱗片状、繊維状の充填材を脱臭装置に充填する作業は、その作業性や粉塵の発生など作業間環境が悪い。
（３）脱臭装置に均一に充填材が充填できないために、上記の悪臭ガスの偏流れを起こる。
（４）臭気成分の分解生成物である硫酸イオンなどが充填層に蓄積すると、強酸性のために微生物が死滅したり、塩濃度の上昇により微生物の活動が停止する。また、臭気成分の分解に伴い微生物が増殖し、増殖した微生物により充填層が閉塞する。これらを防止するために充填層に定期的又は連続的に散水され、硫酸イオンや塩や増殖微生物が洗い流され、充填層の微生物の生息環境が維持される。しかしながら、溶解性の塩は散水により充填層から除去されやすいが、増殖微生物は、困難である。
【０００５】
【発明が解決しようとする課題】
本発明は、上記の従来技術の問題点を解決し、脱臭性能を向上させると共に、設備費の低減が図れる生物脱臭用充填材と、それを用いる生物脱臭方法及び装置を提供することを課題とする。
【０００６】
【課題を解決するための手段】
上記課題を解決するため、本発明では、三次元網目構造でその内部に連通空間を有する板状多孔体で、直線上２５ｍｍ当りに並ぶ気泡数が異なる複数の板状多孔体からなることを特徴とする悪臭ガスの生物脱臭用充填材としたものである。前記脱臭用充填材において、気泡数の異なる２種類の板状多孔体は、直線上２５ｍｍ当りに並ぶ気泡数が、５〜９個と１０〜１５個の組合せ、又は、１０〜１５個と２０個以上の組合せであるのがよい。
また、本発明では、粒径が異なる無機粒状充填材を別々に任意の形状の型枠に充填した複数のモジュールからなることを特徴とする悪臭ガスの生物脱臭用充填材としたものである。
前記脱臭用充填材において、気泡数が異なる複数の板状多孔体、又は、粒径が異なる無機粒状充填材のモジュールは、交互に配備するか、又は、ガス流入部に近い順に、気泡数の小さい板状多孔体又は粒径が大きいモジュールから、気泡数が大きい板状多孔体又は粒径が小さいモジュールの順に配備することができる。
【０００７】
また、本発明では、三次元網目構造でその内部に連通空間を有する板状セラミックス多孔体からなることを特徴とする悪臭ガスの生物脱臭用充填材としたものである。
該脱臭用充填材において、板状セラミックス多孔体は、直線上２５ｍｍ当りに並ぶ気泡数が５〜５０個であるのがよい。
また、本発明では、三次元網目構造でその内部に連通空間を有する板状セラミックス多孔体と板状プラスチック発泡体又は板状繊維状充填材とを、交互に配置したモジュール構造からなることを特徴とする悪臭ガスの生物脱臭用充填材としたものである。
また、本発明では、粒状又は破砕状の多孔質無機物質粒子を接点で接着させて板状又は円柱状の集合体に成形した成形物からなることを特徴とする悪臭ガスの生物脱臭用充填材としたものである。
該脱臭用充填材において、前記成形物は、側面に直線状に複数の凹又は複数の凸を形成することができる。
【０００８】
さらに、本発明では、前記した本発明の脱臭用充填材を充填した充填層に微生物を付着させ、悪臭ガスと接触させて生物学的に脱臭することを特徴とする悪臭ガスの生物脱臭方法としたものである。
前記脱臭方法において、脱臭用充填材に板状セラミックス多孔体を用いた場合は、該充填材は、少なくとも最終充填層に使用するのがよい。
また、本発明では、充填層と充填層に散水する手段を有する生物学的な悪臭ガスの脱臭装置において、前記充填層が、前記した本発明の脱臭用充填材を充填した充填層で構成されることを特徴とする悪臭ガスの生物脱臭装置としたものである。
【０００９】
【発明の実施の形態】
以下に本発明を詳細に説明する。
本発明は、悪臭ガスの生物脱臭用充填材と、該充填材を充填した充填層に微生物を付着させて、悪臭ガスを接触させて生物学的に脱臭する脱臭方法と装置である。
本発明で脱臭する悪臭ガスは、硫化水素とアンモニア、フェノール、有機酸、アルデヒド類、硫化メチルや二硫化メチル等の有機硫黄化合物等の少なくとも１種類以上を含むガスである。もちろん、硫化水素単独でも前述した硫化水素以外の悪臭成分のうち少なくとも１種類以上含んでいてもよい。
本発明の生物脱臭は、充填層を有する充填塔式生物脱臭法と装置である。
生物脱臭装置の型式は、縦型と横型の２種類あり、いずれにも本発明は適用できる。縦型生物脱臭装置は、図１に示すように悪臭ガスが上向き、又は下向きであり、充填層を湿潤状態にするために散水されるが、この散水の流れと悪臭ガスの流れ方向は、並行又は交流である。横型は、悪臭ガスが建物の床と並行にながれ、悪臭ガスと散水の流れ方向は、垂直である。
【００１０】
縦型脱臭装置では、充填材を積み重ねてできた高さが、充填層高さである。
横型脱臭装置では、充填材を横に並べた長さが、充填層長さ（充填層高さ）になる。また、脱臭塔１断面部への充填材の配備は、任意の大きさのものを脱臭塔１断面部に敷き詰めることにより充填層断面部を形成する。厚み以外のモジュールの寸法は、生物脱臭装置の断面の形状や大きさにより任意に決定される。
ブロック状に充填材を配備して、充填層を形成するために、粒状やサイコロ状の充填材のように圧密することがなく、充填層の部分的に発生した圧力損失の高い部分を避けて悪臭ガスが充填層内を通過するガスの偏流という重大な問題が解消される。このために充填層全体が均一に効果的に利用されるので、脱臭性能が高く維持される。
充填層を湿潤状態に維持するために充填層上部に散水するが、その散水に用いる液は充填層を通過した液を再び、散水に使用してもよい。また、工業用水、生物処理水等を直接、充填層上部から散水することもできる。散水においても悪臭ガスと同様に散水の水の偏流という重大な問題が解消される。
散水は連続的でも散水時間をある範囲に設定した間欠的でもよい。散水量は単位処理ガス量当り０．１〜５リットル／ｍ３−ガス、通常３リットル／ｍ３−ガスである。
その補給水は工業用水、生物処理水等いずれも使用できる。
【００１１】
図１に縦型生物脱臭装置の概略図で生物脱臭を説明する。
生物脱臭塔１の充填層３に付着する微生物の馴致を行う。微生物を含む活性汚泥等の種汚泥を受水部５に添加し、循環ポンプで散水部４から散水する。悪臭ガス６を脱臭塔底部に導入し、脱臭を開始する。脱臭塔上部から処理ガス７が大気中に排出される。さらに脱臭が必要なら、活性炭吸着装置に供給される。硫化水素除去率が８０％以上になれば、充填層に悪臭成分が分解できる微生物が付着したと判断でき、馴致が終了する。馴致終了後、悪臭ガス量を増やして定常運転を行う。悪臭成分の分解が進行し、循環水中に硫酸が蓄積すると脱臭効果が低下する。このために補給水９を受水部５に補給することによって循環液などのの硫酸濃度を下げて、微生物の活性を維持する。
【００１２】
本発明の充填材は、まず、三次元網目構造で、その内部に連通空間を有する板状多孔体で、直線上２５ｍｍ当りに並ぶ気泡数が異なる複数の板状多孔体である。板状多孔体は、三次元網目構造で、複数の空間が骨格で構成されて、内部に連通空間があり、悪臭ガスや散水の水が容易に通過するものである。
板状多孔体は、２５ｍｍ直線上の気泡数が５〜３０個である。板状多孔体は、セラミックス多孔体やスポンジ発泡体、繊維状充填材がある。
板状セラミックス多孔体は、市販の溶融金属ろ過材や排ガス処理用充填材や化学合成用など触媒担体のものが使用できる。その製造方法の一例として、三次元網目構造でその内部に連通空間を有する合成樹脂体にセラミックススラリーを付着させ、これを焼成することにより板状セラミックス多孔体を得る。
スポンジ発泡体は、ポリプロピレンなどの合成樹脂やウレタンフォームで、断熱材などに利用されている市販品が充填材に適用できる。繊維状充填材は、化学繊維で空間を形成したもので、薬液洗浄脱臭装置のエリミネターの充填材が使用できる。
【００１３】
板状には、直方体、円柱状を含み、一枚当り厚みは任意にできるが、充填材コストを考慮して市販品を使用すると、その厚みは５〜５０ｍｍである。直線上２５ｍｍ当りに並ぶ気泡数が異なる多孔体で形成されたモジュールを２種類又は複数用意し、生物脱臭装置に配備する。
直線上２５ｍｍ当りに並ぶ気泡数が異なる複数の板状多孔体を順次重ね合わせて充填層を形成する。気泡数が異なる板状多孔体の重ね合わせる順序は、任意に決定できる。同じ気泡数が板状多孔体を複数重ねたのちに気泡数が異なる板状多孔体を一枚又は複数重ねてもよい。
直線上２５ｍｍ当りに並ぶ気泡数が多いと、気泡内面が占める表面積が大きく、多孔体全体の表面積が大きい。逆に気泡数が少ないほうが、多孔体の断面積が小さい。
直線上２５ｍｍ当りに並ぶ気泡数が異なる多孔体で構成されたモジュールを任意に組合せて、生物脱臭装置に充填層を形成させることにより、直線上２５ｍｍ当りに並ぶ気泡数が多く、多孔体の表面積が大きい多孔体で構成されたモジュールでは、表面積が大きいので脱臭性能が高い。充填層高さ方向で、複数の区間で気泡数や多孔体の表面積が異なる充填層を形成させることで、経験的に悪臭ガスの偏流が防止でき、脱臭性能が向上する。
【００１４】
また、本発明では、その直線上２５ｍｍ当りに並ぶ気泡数の異なる２種類の板状多孔体は、気泡数が５〜９個に対して気泡数が１０〜１５個、又は、気泡数が１０〜１５個に対して気泡数が２０個以上である組合せとするのがよい。
気泡数は、上記範囲であれば、任意に組合せることができる。２種類の板状多孔体を組合せて充填層を形成する場合、板状多孔体の直線上２５ｍｍ当りに並ぶ気泡数が１０個に対して、他方の板状多孔体は、５個又は３０個とするのが好適である。気泡数が１０個程度の板状多孔体は、その表面積が広くて、圧力損失を低く抑えられることから、硫化水素濃度が数十ｐｐｍ以下の中濃度悪臭ガスを脱臭するのに好適である。この気泡数が１０個程度の板状多孔体を基準に、悪臭ガス濃度が高い場合が予想されるなら、気泡数が５個程度の板状多孔体を組合せる。
硫化水素濃度が１ｐｐｍ以下の低濃度悪臭ガスを十分に脱臭したい場合には、気泡数が１０個程度の板状多孔体と、気泡数が２０個以上の板状多孔体を組合せる。
【００１５】
硫化水素濃度が数十ｐｐｍ以上のような悪臭ガス濃度が高い場合には、充填層で生成する微生物量が多いので、空隙の大きい板状多孔体の直線上２５ｍｍ当りに並ぶ気泡数５個程度が望ましい。硫化水素濃度が数ｐｐｍのような悪臭ガス濃度が中程度の場合には、充填層で生成する微生物量が少ないので、空隙が中程度の板状多孔体の直線上２５ｍｍ当りに並ぶ気泡数１０〜１５個程度が望ましい。硫化水素濃度が１ｐｐｍ以下のような悪臭ガス濃度が低く、生物脱臭装置の後段の仕上げ処理としての活性炭吸着装置を設置しない場合には、充填層で生成する微生物量が少なく、処理ガス濃度を可能な限り低くする必要があるので、表面積が大きく、空隙の小さい直線上２５ｍｍ当りに並ぶ気泡数が２０個以上の板状多孔体の使用が望ましい。
直線上２５ｍｍ当りに並ぶ気泡数が大きいほど、脱臭性能が高いが、空隙が狭いので充填層の圧力損失が高まり脱臭自体が困難になる。
脱臭性能を高く維持しつつ、充填層の圧力損失を低くするのは、直線上２５ｍｍ当りに並ぶ気泡数の異なる板状多孔体を使用する。
【００１６】
また、本発明は、粒径が異なる無機粒状充填材を、別々に直方体又は円柱状など任意の形状の型枠に充填した複数のモジュールからなる悪臭ガスの脱臭用充填材である。
図３に、無機粒状充填材を直方体の型枠１２に充填したモジュール１１の概略図を示す。
無機粒状充填材をバラで任意の形状の型枠に充填する。この型枠をモジュールとし、粒径が異なる無機粒状充填材のモジュールを任意に組合せて脱臭装置に配備し、充填層を形成する。
無機粒状充填材は、セラミックス粒子、炭化物などで、その粒径は、１〜１０ｍｍである。無機粒状充填材は任意の形状のものが使用できる。
型枠は、無機粒状充填材がこぼれない程度の網状で全体を覆い、プラスチックやＦＲＰでその周囲を補強したのもが使用できる。
型枠には、異なる粒径の充填材による最密充填が起きないように、均等係数が１．２以下のほぼ同じ粒径の無機粒状充填材を充填する。
【００１７】
本発明では、直線上２５ｍｍ当りに並ぶ気泡数が異なる２つの板状多孔体を交互に配備して脱臭用充填材とできる。板状多孔体の気泡数は、任意に組合せることができる。２種類の板状多孔体を組合せて充填層を形成する場合、板状多孔体の直線上２５ｍｍ当りに並ぶ気泡数が１０個に対して、他方の板状多孔体は、５個又は３０個とするのが好適である。直線上２５ｍｍ当りに並ぶ気泡数が１０個の板状多孔体と気泡数が５個又は３０個の板状多孔体を交互に配備することで充填層が形成できる。板状多孔体の交換や配備の作業性を考慮して板状多孔体と板状多孔体との間に任意の空間を空けることができる。
【００１８】
また、本発明では、粒径が異なる２つの無機粒状充填材のモジュールを交互に配備して脱臭用充填材とできる。粒径が１ｍｍ以下の無機粒状充填材からなるモジュールと粒径が１〜３ｍｍの無機粒状充填材からなるモジュール又は、粒径が１〜３ｍｍの無機粒状充填材からなるモジュールと粒径が４〜２０ｍｍの無機粒状充填材からなるモジュールを組合せて、充填層とする。
無機粒状充填材の粒径が１〜３ｍｍに対して、他方の無機粒状充填材は、１ｍｍ以下又は４〜２０ｍｍとするのが好適である。充填層の圧力損失を抑えるなら、粒径の小さい無機粒状充填材１枚に対して、粒径の大きい無機粒状充填材のモジュール数を２〜１０と多くするように配備する。
さらに、本発明では、ガス流入部に近い順に、気泡数の小さい板状多孔体又は粒径が大きいモジュールから、気泡数が大きい板状多孔体又は粒径が小さいモジュールの順に配備して充填用充填材とできる。
板状多孔体と無機粒状多孔体のモジュールからなる充填用充填材は、それぞれ単独又は、併用して充填層に充填する。
【００１９】
図４に、モジュール構造を有する充填層で構成される横型生物脱臭装置の概略図を示す。
ガス流入部に近い充填層部は、悪臭ガスの臭気成分の負荷が大きく、分解過程で増殖する微生物量が多くなり、圧力損失が部分的に増加する。圧力損失の増加を抑えるために、ガス流入部に近い充填層部は、気泡数の小さい板状多孔体又は、粒径が大きいモジュールを配備する。充填層出口に近づくにつれ悪臭ガスが処理され、充填層部での圧力損失が抑えられる。このために充填層出口部では、気泡数が大きい板状多孔体又は粒径が小さいモジュールを配備する。
ガス流入部に近い充填層部に気泡数の小さい板状多孔体又は粒径が大きいモジュールを配備することで、散水により、充填層に付着する増殖微生物が剥離、洗い流され易く充填層の圧力損失が低く維持できる。一方、充填層出口部に配備した気泡数が大きい板状多孔体又は粒径が小さいモジュールは、悪臭ガスや散水との接触効率は高く、臭気成分濃度が処理されて薄くなった悪臭ガスがさらに脱臭される。
【００２０】
次に、本発明において、気泡数が異なる複数の板状多孔体を交互に配置した充填材又は、粒径が異なる複数の無機粒状多孔体を交互に配置したモジュール構造を有する充填材を充填した充填層で構成される悪臭ガスの脱臭装置について説明する。
図５は、モジュール構造を有する充填層で構成される横型生物脱臭装置の概略図である。悪臭ガス流入方向から出口方向に、気泡数が異なる複数の多孔体を交互に配置した充填層、又は、粒径が異なる複数の無機粒状多孔体のモジュール構造体を交互に配置して、充填層を形成する。充填層上部には散水設備を設ける。散水部は、充填層上部に満遍なく散水できるように、充填層上部面積０．５〜１ｍ２当りに散水ノズル１個を配置する。散水は、受水部からの循環液でも生物処理水などでもよい。
【００２１】
脱臭装置は、横型でも縦型でもよい。
横型脱臭装置では、各々のモジュール又は板状多孔体を脱臭装置外にスライドさせて取り出される構造を有するものが好適である。充填層のうち閉塞気味のモジュール又は板状多孔体を取り出し、高圧水による洗浄や薬品洗浄を行い、閉塞を解消させ、その後、充填層に戻す。脱臭装置を停止する時間が少ないので、脱臭装置以外の影響や脱臭性能の低下が防止できる。又は、悪臭ガス流入部付近のモジュール又は板状多孔体と出口部付近のモジュール又は板状多孔体を交換することもできる。出口部付近に置き換えられた閉塞気味のモジュール又は板状多孔体は、出口部で臭気成分の負荷量が少ないために出口部付近のモジュール又は板状多孔体に付着する微生物は、減少傾向をたどり、最終的に閉塞が解消できる。
【００２２】
次に、本発明の三次元網目構造でその内部に連通空間を有するセラミックス多孔体からなる充填材について説明する。
三次元網目構造でその内部に連通空間を有する板状セラミックス多孔体は、市販の溶融金属ろ過材や排ガス処理用充填材や化学合成用など触媒担体のものが使用できる。その製造方法の一例として、三次元網目構造でその内部に連通空間を有する合成樹脂体にセラミックススラリーを付着させ、これを焼成することにより板状セラミックス多孔体を得る。
板状には、直方体、円柱状を含み、一枚当り厚みは任意にできるが、充填材コストを考慮して市販品を使用すると、その厚みは５〜５０ｍｍである。
板状セラミックス多孔体は、複数枚積み重ねることにより充填層を構成する。板状セラミックス多孔体を積み重ねてできた高さが、充填層高さである。また、脱臭塔断面部への板状セラミックス多孔体の配備は、任意の大きさのものを脱臭塔断面部に敷き詰めることにより充填層断面部を形成する。
【００２３】
本発明の板状セラミックス多孔体は、直線上２５ｍｍ当りに並ぶ気泡数が５〜５０個であるのがよい。直線上２５ｍｍ当りに並ぶ気泡数が多いと、多孔体の一つの空間の断面積が小さく、空間が占める表面積が大きく、多孔体の表面積が大きい。逆に気泡数が少ないほうが、多孔体の一つの空間の断面積が大きい。
直線上２５ｍｍ当りに並ぶ気泡数が多い方が、悪臭ガスとの接触面積が大きく、脱臭効果が高いが、目詰まりし易く、充填層の圧力損失が増加する。
直線上２５ｍｍ当りに並ぶ気泡数が４個以下では、臭気除去性能が低い。５０個を超えると、目詰まりし易く、充填層の圧力損失が増加する。
また、本発明の板状セラミックス多孔体は、少なくとも最終充填層に使用するのがよい。生物脱臭装置が１つの充填塔で構成され、その充填塔に複数の充填層がある場合には、少なくとも最終充填層に板状セラミックス多孔体を充填する。
【００２４】
生物脱臭装置が複数の充填塔で構成されている場合には、最終の充填塔もしくは最初の充填塔を除く充填塔が本発明の対象となる。
最初の充填塔では、生物的に除去されやすい硫化水素やアンモニアが容易に除去できるために、本発明の板状セラミックス多孔体を使用する必要はない。
悪臭成分のうちアンモニアや硫化水素あるいはメチルメルカプタンは、悪臭ガスの流入部に近い充填層で容易に除去できる。しかしながら、硫化メチルや二硫化メチルの除去速度が遅いので、悪臭ガスとの接触効率が高い板状セラミックス多孔体が有効である。
図６に２塔式縦型生物脱臭装置の概略図を示す。悪臭ガス６は、第１塔脱臭塔１’の充填層３’を経由して第１塔処理ガス７’となり、第１塔処理ガス７’が第２塔脱臭塔１”に導かれ、その充填層３で脱臭されて第２塔処理ガス７として排出される。２塔式縦型生物脱臭装置の最終充填層とは、第２塔脱臭塔の充填層３である。
【００２５】
また、本発明は、前記の板状セラミックス多孔体と、板状プラスチック発泡体又は板状繊維状充填材とを、交互に配置したモジュール構造を有する充填用充填材である。
使用できる板状プラスチック発泡体は、ポリプロピレンなどの合成樹脂を成形した市販の充填材でもよいが、脱臭効率が高いスポンジ充填材がよい。このスポンジ充填材の形状は、セル数（２５ｍｍ直線上のセル、気泡数）５〜３０で、その内部に連通空間を有するものである。
また、使用できる板状繊維状充填材は、ポリ塩化ビリニデンなどの化学繊維又はピートモスなどの天然繊維を板状に成形加工したものである。ポリ塩化ビリニデンなどの板状繊維状充填材は、エリミネーターのミスト分離として市販されているものが使用できる。
ピートモスなどの天然繊維は、そのままを板状に加圧成形してもよいし、上記化学繊維の支持体に絡ませてもよい。
【００２６】
板状セラミックス多孔体と板状プラスチック発泡体、又は、板状セラミックス多孔体と板状繊維状充填材を交互に配置することにより、充填層高さ方向の板状セラミックス多孔体同士の隙間や充填層断面部での板状セラミックス多孔体の隙間が、板状プラスチック発泡体又は板状繊維状充填材で埋められ、悪臭ガスの偏流が抑えられる。
充填層高さ方向に、板状セラミックス多孔体１〜５枚に対して、板状プラスチック発泡体又は板状繊維状充填材１枚を重ね合わせたものを１組のモジュールとする。このモジュールを複数使用して充填層を構成する。
図７は、板状セラミックス多孔体と板状プラスチック発泡体又は板状繊維状充填材を交互に配置したモジュール構造の概略図を示す。これは、板状セラミックス多孔体と板状繊維状充填材を一枚づつ交互に配備したモジュール構造である。
【００２７】
ガス流れ方向に、板状セラミックス多孔体と板状プラスチック発泡体又は板状繊維状充填材を配備する。また、板状セラミックス多孔体の間に板状プラスチック発泡体又は板状繊維状充填材が配備されるように配置することができる。
板状セラミックス多孔体や板状繊維状充填材や板状プラスチック発泡体は、それぞれを目開き１００ｍｍ程度のステンレス製又はプラスチック製の網で全体又は側面を補強することができる。
また、板状セラミックス多孔体と板状プラスチック発泡体又は板状繊維状充填材を型枠に入れて、補強してもよい。フレーム部は、プラスチック材やステンレス鋼で補強し、側面部は、金網やプラスチックの網とすることができる。
【００２８】
また、本発明において、モジュール構造を有する前記の脱臭用充填材からなる充填層で構成される横型生物脱臭装置である悪臭ガスの脱臭装置について説明する。
図８にその概略図を示す。板状セラミックス多孔体と板状繊維状充填材を一枚づつ交互に配備したモジュール構造からなる充填材ＡからＦで充填層が構成される。モジュール構造ＡからＦは、密着させてもよいし、モジュール構造ＡとＢ、ＢとＣなどの境に空間を設けてもよい。空間を設けると、微生物の繁殖でその微生物量が増加したところのモジュールを装置の外に取り出し、水や過酸化水素などの薬品で洗浄するのに好都合である。また、板状セラミックス多孔体を複数枚と板状繊維状充填材を一枚を交互に配備してもよい。
散水は、モジュールの上部から行い、個々のモジュールに複数の散水ノズルを配備した１系列の散水部を設ける。
【００２９】
また、本発明の充填材は、粒状又は破砕状の多孔質無機物質粒子を接点で接着させて板状又は円柱状の集合体に成形した成形物である。この成型物は、個々の粒子により三次元構造が形成され、その内部に連通空間を有するので、悪臭ガスや散水の水が容易に通過するものである。
市販の板状セラミックス多孔体は、その大きさが限られており、実装置の充填材に使用する場合には、それらをつなぎ合わせて、一つの板状セラミックス多孔体とするか、又は、人手により小さい寸法のまま充填層に敷詰めることになる。粒状又は破砕状の多孔質無機物質粒子は、市販のセラミックス粒子やアンスラサイト、砂、炭化物などで粒径が１〜２０ｍｍである。多孔質無機物質粒子は、最密充填が起きないように、均等係数が１．２以下のほぼ同じ粒径である。これらの粒子を接着させて成形物にすると、成形物の空間の大きさは、０．２〜５ｍｍである。
【００３０】
多孔質無機物質粒子同士の接着方法には、制限はない。接着方法の一例として、ベントナイトの１０％程度のスラリーに多孔質無機物質粒子を添加し、多孔質無機物質粒子から余分のスラリーを重力分離して除去した後、９００℃以上で焼成し、粒子同士を結合させる。多孔質無機物質粒子同士が接触する部分だけに化学接着剤が塗布でき、それ以外の多孔質無機物質粒子表面に、化学接着剤が付着しない方法が採用できる。
成形物の形状には、直方体、円柱状を含み、一枚当りの厚みは任意にできるが、作業性や散水時の水の分散性を考慮すると、その厚みは５〜５０ｍｍである。多孔質無機物質粒子の粒径が異なる複数の成形物を順次重ね合わせて充填層を形成する。重ね合わせる順序は、任意に決定できる。同じ粒径の成形物を複数重ねたのちに、異なる粒径の成形物を一枚又は複数重ねてもよい。
板状多孔体の交換や配備の作業性を考慮して、成形物と成形物との間に任意の空間を空けることができる。
【００３１】
また、本発明では、前記板状多孔体の側面に、直線状に複数の凹又は複数の凸を形成した加工物を充填材とすることができる。
板状多孔体は、セラミックス多孔体が好適である。セラミックス多孔体は、その内部に連通空間を有し、３次元網目構造であるので、悪臭ガスと微生物との接触効率が高く、圧力損失が低いのが特徴である。脱臭性能からセラミックス多孔は、体は、その直線上２５ｍｍ当りに並ぶ気泡数が５〜３０個が好適である。
凹部や凸部の形状は、半球状や三角錐状や直方体状など任意に決定できる。
図９に、板状多孔体の側面に直線状に複数の凹又は複数の凸を形成した加工物を示す。凹部や凸部は、連続した直線上にある。図９のＡは、半球状の凹部を片面に加工したもの、図９のＢは、同じ位置に両面凹部を加工したものである。図９のＣは、半球状の凸部を片面に、Ｄは、直方体状の凸部を片面に、Ｅは、直方体状の凹部を片面に、Ｆは、三角錐状の凸部を片面状に加工したものである。
【００３２】
横型脱臭装置であれば、図９のように悪臭ガスは、板状多孔体に垂直に、散水の循環液などは、板状多孔体に平行に流れる。散水された循環液は、凹部に主に流れ、凸部の加工物なら凸部で形成される凹部に循環液が流れ、充填層に蓄積した塩類や増殖した微生物が容易に充填層外に洗い流される。多量の循環液を充填層に散水しても、速やかに排出されるので、運転中でも充填層の散水による急激な圧力損失が生じず、圧力損失の増大による悪臭ガスの流入停止は起こらない。多量の循環液を散水することにより、除去しにくい増殖微生物が容易に充填層から排出される。循環液の散水量を任意に変えることにより、最適な増殖微生物が除去できる。板状多孔体の側面、悪臭ガスや循環液が接する面に形成された凹部や凸部と凸部でできた凹部が循環液の排水溝となり、充填層から循環液や散水の水が容易に排出される。この結果、充填層の圧力損失を低く維持できる。
縦型脱臭塔なら、悪臭ガスの流れは、横型と同じであるが、散水の水の流れ方向は、板状多孔体に垂直である。
【００３３】
１枚の加工物の片面に凹凸部を設けてもよいし、両面に設けてもよい。また、片面の凹凸部の位置をずらしてもよい。凹部の深さや凸部の高さに制限はないが、概ね数〜３０ｍｍである。数ｍｍ未満では、元々板状多孔体には、この程度の凹凸があり、凹凸部の効果がでない。３０ｍｍを超えると、加工物の強度が低下する。
凹凸部の配置は、凹部又は凸部の間口の合計の長さが、凹部又は凸部が配備される加工物の１辺の長さの５０〜２０％である。配置から５０％は最大であり、２０％未満では、散水量を速やかに排除できない。
気泡数が１０個程度の板状多孔体は、その表面積が広くて、圧力損失を低く抑えられることから、硫化水素濃度が数十ｐｐｍ以下の中濃度悪臭ガスを脱臭するのに好適である。硫化水素濃度が数十ｐｐｍ以上のような悪臭ガス濃度が高い場合には、充填層で生成する微生物量が多いので、空隙の大きい板状多孔体、直線上２５ｍｍ当りに並ぶ気泡数５個程度が望ましい。硫化水素濃度が数ｐｐｍのような悪臭ガス濃度及び中程度の場合には、充填層で生成する微生物量が少なくので、空隙が中程度の板状多孔体、直線上２５ｍｍ当りに並ぶ気泡数１０〜１５個程度が望ましい。
【００３４】
また、本発明では、前記の集合体の側面に直線状に複数の凹又は複数の凸を形成した加工物を充填材とすることができる。
１枚の加工物の悪臭ガスの通過する片面に凹凸部を設けてもよいし、両面に設けてもよい。また、片面の凹凸部の位置をずらしてもよい。凹部の深さや凸部の高さに制限はないが、概ね１０〜３０ｍｍである。１０ｍｍ未満では、元々の集合体には、この程度の凹凸があり、凹凸部の効果がでない。３０ｍｍを超えると、加工物の強度が低下する。
また、悪臭ガスが通過する片面にある凹凸部を悪臭ガスの流入方向又は、出口方向、いずれになるように充填層に配置してもよい。
凹凸部の配置は、凹部又は凸部の間口の合計の長さが、凹部又は凸部が配備される加工物の１辺の長さの５０〜２０％である。配置から５０％は最大であり、２０％未満では、散水量を速やかに排除できない。
【００３５】
さらに、本発明では、前記の加工物を配備した充填層を有する生物脱臭装置とすることができる。
図２の横型生物脱臭装置の概略図で説明する。
充填材は、その側面に複数の凹又は複数の凸を形成した板状セラミックス多孔体や、その側面に複数の凹又は複数の凸を形成した多孔質無機物質粒子の成形物であり、これら充填材を重ねて、あるいは一定の間隔をあけて充填することにより充填層を形成する。横型脱臭装置であるので、悪臭ガス流入方向と側面の凹凸部が垂直になるように充填層が設けれる。処理ガスが、流入方向と反対方向から排出される。充填層上部には、散水設備を設ける。散水部は、充填層上部に満遍なく散水できるように、充填層上部面積０．５〜１ｍ２当り散水ノズル１個を配置する。
【００３６】
【実施例】
以下、本発明を実施例により具体的に説明する。
実施例１
図２の横型生物脱臭装置で、充填層断面積が０．３６ｍ２、充填層高（充填層のガス入口部から充填層出口部までの距離）１ｍを用いて実験した。
原ガスの組成は、硫化水素が５ｐｐｍ、メチルメルカプタンが２ｐｐｍ、硫化メチルが１ｐｐｍである。
板状セラミックス多孔体は、縦横０．６ｍ、厚みが０．１ｍの三次元網目構造で、その内部に連通空間を有するウレタン合成樹脂体に粒径１０μｍの酸化アルミナ９０％以上のセラミックススラリーを付着させ、これを９００℃で１時間焼成することにより製造した。板状多孔体の気泡数は、三次元網目構造でその内部に連通空間を有する合成樹脂体の気泡数を任意に設定した。
原ガス流入部方向に、直線上２５ｍｍ当りに並ぶ気泡数が５個の板状セラミックス多孔体を２〜５枚、出口方向に気泡数が１５個の板状セラミックス多孔体を５〜８枚、又は、原ガス流入部方向に、気泡数が１５個の板状セラミックス多孔体を２〜５枚、出口方向に、気泡数が３０個の板状セラミックス多孔体を５〜８枚組合せて充填層を形成した。
【００３７】
実験条件は、空塔速度５００ｈ−１、単位処理ガス量当りの散水量が、３リットル／ｍ３、連続散水、ガス温度２０〜２５℃、循環水汚泥濃度数十ｍｇ／ｌ（初期濃度；約２０００ｍｇ／ｌ、循環水のｐＨが２〜４、補給水には生物処理水の砂ろ過水を用いた。循環水の汚泥濃度を約２０００ｍｇ／ｌに調整後、悪臭ガスを連続的に通気しつつ、循環水を連続的に充填層に散水した。約１週間後には、硫化水素除去率が９０％となり、馴致が完了した。
馴致後、２週間経過後の臭気成分の除去率と充填層の圧力損失を表１に示す。同一の気泡数を有する板状セラミックス多孔体を充填層にするより、異なる気泡数の板状セラミックス多孔体を使用する方が、充填層の圧力損失が小さく、臭気成分の除去率が高くて脱臭性能は良好であった。
【００３８】
【表１】
【００３９】
実施例２
実施例１の実験装置に、気泡数が異なる２つの板状多孔体を交互に配備して、充填層を形成し、実施例１と同様に実験した。
原ガス流入部から出口方向に向かって、実施例１の直線上２５ｍｍ当りに並ぶ気泡数が５個の板状セラミックス多孔体を１枚と気泡数が１５個の板状セラミックス多孔体１〜４枚を交互に、実施例１の気泡数が１５個の板状セラミックス多孔体を１枚と気泡数が３０個の板状セラミックス多孔体１〜４枚を交互に組合せて充填層を形成した。表２に臭気成分の除去率と充填層の圧力損失を示す。
異なる気泡数の板状セラミックス多孔体を、交互に充填層に配備して使用する方が、充填層の圧力損失が小さく、臭気成分の除去率が高くて脱臭性能は良好であった。
【００４０】
【表２】
【００４１】
実施例３
実施例１の実験装置に粒径が異なる無機粒状充填材のモジュールを交互に配備して、充填層を形成し、実施例１と同様に実験した。
無機粒状充填材は、鋳物鋳造工程から排出される集塵ダストを所定の大きさに造粒したものを、空気雰囲気で約９００℃で焼成して製造し、焼成物を分級したものである。無機粒状充填材の粒径は１ｍｍと３ｍｍと１０ｍｍで、いずれの均等係数は１．２である。
粒径１ｍｍの無機粒状充填材を、幅０．１ｍ、縦横０．６ｍのＦＲＰ製の直方体の型枠に目開き１ｍｍのナイロン繊維製の糸で網状にしたものに充填し、これをモジュールとした。
粒径３ｍｍの無機粒状充填材は、目開き３ｍｍのナイロン繊維製の糸で網状覆われた型枠に充填し、粒径１０ｍｍの無機粒状充填材は、目開き５ｍｍのナイロン繊維製の糸で網状覆われた型枠に充填した。
【００４２】
原ガス流入部方向に粒径３ｍｍの無機粒状充填材モジュールを２〜５枚、出口方向に粒径１ｍｍの無機粒状充填材モジュールを５〜８枚、又は、原ガス流入部方向に粒径１０ｍｍの無機粒状充填材モジュールを２〜５枚、出口方向に粒径３ｍｍの無機粒状充填材モジュールを５〜８枚組合せて充填層を形成した。
馴致後、約６週間経過後の臭気成分の除去率と、充填層の圧力損失を表３に示す。
同一の粒径の無機粒状充填材モジュールだけを充填層にするより、異なる粒径の無機粒状充填材モジュールを組合せる方が、充填層の圧力損失が小さく、臭気成分の除去率が高くて脱臭性能は良好であった。
【００４３】
【表３】
【００４４】
実施例４
実施例１の実験装置に、粒径が異なる２つの無機粒状充填材のモジュールを交互に配備して、充填層を形成し、実施例１と同様に実験した。
原ガス流入部から出口方向に向かって、実施例３の粒径３ｍｍの無機粒状充填材モジュールを１枚に対して粒径１ｍｍの無機粒状充填材モジュールを１〜４枚を交互に、実施例３の粒径１０ｍｍの無機粒状充填材モジュールを１枚に対して粒径３ｍｍの無機粒状充填材モジュール１〜４枚を交互に組合せて充填層を形成した。
表４に、臭気成分の除去率と充填層の圧力損失を示す。
異なる粒径の無機粒状充填材モジュールを交互に充填層に配備することにより使用する方が、充填層の圧力損失が小さく、臭気成分の除去率が高くて脱臭性能は良好であった。
【００４５】
【表４】
【００４６】
実施例５
実施例１の実験装置にガス流入部から気泡数の小さい板状多孔体又は、粒径が大きい２つの無機粒状充填材モジュールの順に配備して、充填層を形成し、実施例１と同様に実験した。
板状多孔体は、原ガス流入部から出口方向に向かって、実施例１の直線上２５ｍｍ当りに並ぶ気泡数が５個の板状セラミックス多孔体を２〜４枚、実施例１の気泡数が１５個の板状セラミックス多孔体を２〜４枚、気泡数が３０個の板状セラミックス多孔体を２〜４枚で充填層を形成した。
無機粒状充填材モジュールは、原ガス流入部から実施例３の粒径１０ｍｍの無機粒状充填材モジュールを２〜４枚、実施例３の粒径３ｍｍの無機粒状充填材モジュールを２〜４枚を、粒径１ｍｍの無機粒状充填材モジュールを２〜６枚で充填層を形成した。
表５と表６に、臭気成分の除去率と充填層の圧力損失を示す。
気泡数の小さい板状多孔体や大きい粒径の無機粒状充填材モジュールをガス流入部から順に充填層に配備することにより、充填層の圧力損失が小さく、臭気成分の除去率が高くて脱臭性能は良好であった。
【００４７】
【表５】
【００４８】
【表６】
【００４９】
実施例６
実施例１の原ガス濃度をより薄いものに変更して、空塔速度１０００ｈ−１、単位処理ガス量当りの散水量を３リットル／ｍ３、１時間に５分間の間欠散水で、実施例２と同様に実験した。原ガスの組成は、硫化水素が０．５ｐｐｍ、メチルメルカプタンが０．１ｐｐｍ、硫化メチルが０．０５ｐｐｍ、二硫化メチルが０．０５ｐｐｍである。
表７に結果を示す。低濃度臭気でも、気泡数が異なる２つの板状多孔体を交互に配備した充填層にすることにより、脱臭性能を高く維持できる。後段の活性炭吸着装置が不要である。
【００５０】
【表７】
【００５１】
実施例７
実施例３の粒径が異なる２つの無機粒状充填材モジュールを、実施例４のように充填層に配備し、実施例６と同様に試験した。
低濃度臭気でも、粒径が異なる２つの無機粒状充填材モジュールを交互に配備した充填層にすることにより、脱臭性能を高く維持できる。
表８に結果を示す。
板状多孔体の製造において、任意の寸法の板状多孔体が得られにくく、その製造コストがかかるが、既存のセラミックスなどの無機粒状充填材をモジュール化することにより、高価な板状多孔体と同様な脱臭性能が得られた。
【００５２】
【表８】
【００５３】
実施例８
図１の脱臭装置で、充填層断面積が０．３６ｍ２、充填層高１ｍを用いて、実験した。
原ガスの組成は、硫化水素が１０ｐｐｍ、メチルメルカプタンが３ｐｐｍ、硫化メチルが１ｐｐｍである。スポンジ充填材は、直線上２５ｍｍ当りに並ぶ気泡数が５〜２５個のウレタンフォームで、縦横０．６ｍ、厚さ１０ｃｍのものを１０枚重ねた。板状セラミックス多孔体についても、スポンジ充填材と同様の形状のものを１０枚使用して、充填層を形成した。繊維状充填材として、厚さ２０ｍｍの市販のエリミネーター用の充填材（繊維の太さ０．３ｍｍ、ポリ塩化ビリニデン製）を縦横０．６ｍに切断し、２０枚重ねたものを使用した。
【００５４】
実験条件は、空塔速度５００ｈ−１、単位処理ガス量当りの散水量が３リットル／ｍ２、連続散水、ガス温度２０〜２５℃、循環水汚泥濃度数十ｍｇ／ｌ（初期濃度；約２０００ｍｇ／ｌ）、循環水のｐＨが２〜４、補給水には生物処理水を用いた。
循環水の汚泥濃度を約２０００ｍｇ／ｌに調整後、悪臭ガスを連続的に通気しつつ、循環水を連続的に充填層に散水した。約１週間後には、硫化水素除去率が９０％となり、馴致が完了した。
馴致後、２週間経過後の臭気成分の除去率と充填層の圧力損失を表９に示す。板状セラミックス多孔体の脱臭性能は良好であった。
直線上２５ｍｍ当りに並ぶ気泡数が増えると、スポンジ充填材の圧力損失は板状セラミックス多孔体より高い値を示した。
【００５５】
【表９】
【００５６】
実施例９
実施例８の脱臭塔を直列に配備した図６の２塔式縦型生物脱臭装置を用いて、実施例８同様に実験した。実験条件で異なる点は、第１塔の充填材は、実施例８の直線上２５ｍｍ当りに並ぶ気泡数が１５個の板状スポンジ充填材、第２塔の充填材は、実施例１の板状スポンジ充填材、又は、板状セラミックス多孔体である。
馴致終了後、６週間経過した時の第２塔における臭気成分の除去率を表１０に示す。
【００５７】
【表１０】
【００５８】
実施例１０
実施例１の原ガス濃度をより薄いものに変更して、空塔速度１５００ｈ−１、単位処理ガス量当りの散水量を３リットル／ｍ３、１時間に５分間の間欠散水で、実施例１と同様に実験した。原ガスの組成は、硫化水素が０．５ｐｐｍ、メチルメルカプタンが０．１ｐｐｍ、硫化メチルが０．０５ｐｐｍである。
表１１に結果を示す。低濃度臭気でも板状セラミックス多孔体を充填材にすることにより、脱臭性能を高く維持できる。後段の活性炭吸着装置が不要である。
【００５９】
【表１１】
【００６０】
実施例１１
図８の脱臭装置で、充填層断面積が０．３６ｍ２、充填層長さ１ｍを用いて、実施例８の原ガスで、実施例８と同様に実験した。
実施例８の板状セラミックス多孔体単独又は板状セラミックス多孔体とスポンジ充填材一枚ずつで構成されたモジュールを充填して充填層を形成した。
縦横０．６ｍ、厚さ１０ｃｍで、直線上２５ｍｍ当りに並ぶ気泡数が５〜２５個の板状セラミックス多孔体１枚に対して、直線上２５ｍｍ当りに並ぶ気泡数が１０個のウレタンフォームのスポンジ充填材、縦横０．６ｍ、厚さ１０ｃｍのものを１枚重ね、それを目開きが２０ｍｍのプラスチック製網を張ったプラスチックの型枠に収納したもの１組のモジュールにした。１組のモジュールの寸法は、縦横約０．６ｍ、厚さ２０ｃｍであった。
約１週間後には、硫化水素除去率が９０％となり、馴致が完了した。
馴致後、約３週間後には、硫化メチルの除去率が９０％となった。更に２週間経過後の臭気成分の除去率と充填層の圧力損失を表１２に示す。板状セラミックス多孔体の脱臭性能は良好であった。
板状セラミックス多孔体と、スポンジ充填材一枚づつで構成されたモジュールの脱臭性能が高く、圧力損失は、板状セラミックス多孔体単独より低い。
【００６１】
【表１２】
【００６２】
実施例１２
図２の横型生物脱臭装置で、充填層断面積が０．３６ｍ２、充填層高（充填層のガス入口部から充填層出口部までの距離）１ｍを用いて実験した。原ガスの組成は、硫化水素が１ｐｐｍ、メチルメルカプタンが１ｐｐｍ、硫化メチルが１ｐｐｍである。
多孔質無機物質粒子は、鋳物鋳造工程から排出される集塵ダストを所定の大きさに造粒したのもを、空気雰囲気で約９００℃で焼成して製造し、焼成物を分級したものである。多孔質無機物質粒子の粒径は１ｍｍと３ｍｍと１０ｍｍで、いずれの均等係数は１．２である。これら多孔質無機物質粒子１００重量部に対して、粒径１０μｍの酸化アルミナ９０％以上のセラミックススラリーを１００重量部を混合、重力分離ブロック状の型枠（０．６ｍ角、厚さが０．１ｍ）に入れて、再度、空気雰囲気で約９００℃で焼成し、成形物を得た。
従来品で市販品の板状セラミックス多孔体は、縦横０．６ｍ、厚みが０．１ｍの三次元網目構造でその内部に連通空間を有するウレタン合成樹脂体に、粒径１０μｍの酸化アルミナ９０％以上のセラミックススラリーを付着させ、これを９００℃で１時間焼成することにより製造した。板状多孔体の気泡数は、直線上２５ｍｍ当りに並ぶ気泡数が２５個（孔径が約１ｍｍ）、１３個（孔径が約２ｍｍ）である。
【００６３】
原ガス流入部方向に、本発明の成形物又は板状セラミックス多孔体を配備して、充填層を形成した。
実験条件は、空塔速度５００ｈ−１、単位処理ガス量当りの散水量が３リットル／ｍ３、連続散水、ガス温度２０〜２５℃、循環液の汚泥濃度数十ｍｇ／ｌ（初期濃度；約２０００ｍｇ／ｌ）、循環水のｐＨが２〜４、補給水には生物処理水の砂ろ過水を用いた。循環水の汚泥濃度を約２０００ｍｇ／ｌに調整後、悪臭ガスを連続的に通気しつつ、循環水を連続的に充填層に散水した。約１週間後には、硫化水素除去率が９０％となり、馴致が完了した。
更に、４週間経過後の臭気成分の除去率と充填層の圧力損失を表１３に示す。安価な多孔質無機物質粒子成形物の充填材は、市販の高価な板状セラミックス多孔体と同等の脱臭性能が得られた。
【００６４】
【表１３】
【００６５】
実施例１３
その組成が硫化水素１ｐｐｍ、アセトアルデヒド１０ｐｐｍの原ガスを実施例１２の実験装置で、生物脱臭した。循環液は、１０％苛性ソーダ液でｐＨ６〜８に中和した。
実験開始約１０日間で、硫化水素とアルデヒドの除去率が９０％になり、馴致が完了した。馴致終了後、１日間に１回の割合で、単位処理ガス量当りの散水量が１０リットル／ｍ３、約１０分間散水して充填層の洗浄を行った。馴致終了後、約３週間後の充填層の圧力損失と臭気成分の除去率を示す。
【００６６】
直線上２５ｍｍ当りに並ぶ気泡数が、１３個の実施例１２の板状セラミックス多孔体の片面を、図９のＡ又はＣの形状に加工したものと、それら両面に加工したものを装置内部にならべて充填層とした。半円状の凹部の充填材は、図９のＡの形状は、０．６ｍ状に直径が３ｃｍの半円状の凹部を５ｃｍおきに加工したものである。半円状の凸部の充填材は、図９のＣの形状は、０．６ｍ状に直径が３ｃｍの半円状の凸部を５ｃｍおきに加工したものである。結果を表１４に示す。凹凸部のない板状セラミックス多孔体は、充填層の洗浄効果が低く、増殖微生物の剥離が不充分であり、充填層の圧力損失が高く、臭気成分の除去率がやや低かった。脱臭を継続するに従い、増殖微生物の剥離が不充分であるために、この傾向が更に強くなる。また、洗浄のための散水では、一時的に原ガスの流量低下が見られた。凹凸部のある板状セラミックス多孔体は、洗浄効果が十分で、脱臭性能が高く、特に両面に凹凸がある板状セラミックス多孔体の脱臭効果が高い。
【００６７】
【表１４】
【００６８】
実施例１４
実施例１２の粒径３ｍｍ、均等係数１．２の多孔質無機物質粒子の成形物、０．６ｍ角、厚みが０．１ｍの側面に実施例１３と同様の加工を行い、実施例１３と同様に実験した。結果を表１５に示す。
凹凸部のない多孔質無機物質粒子の成形物は、充填層の洗浄効果が低く、増殖微生物の剥離が不充分であり、充填層の圧力損失が高く、臭気成分の除去率がやや低かった。凹凸部のある多孔質無機物質粒子の成形物は、洗浄効果が十分で、脱臭性能が高く、特に両面に凹凸がある多孔質無機物質粒子の成形物の脱臭効果が高い。
【００６９】
【表１５】
【００７０】
実施例１５
実施例１２の原ガス濃度をより薄いものに変更して、空塔速度３００ｈ−１、単位処理ガス量当りの散水量を３リットル／ｍ３、１時間に５分間の間欠散水で、実施例１と同様に実験した。原ガスの組成は、硫化水素が０．５ｐｐｍ、メチルメルカプタンが０．１ｐｐｍ、硫化メチルが０．０５ｐｐｍ、二硫化メチルが０．０５ｐｐｍである。
実施例１２の多孔質無機物質粒子の成形物と、実施例１２の板状セラミックス多孔体とを、充填材に使用した。また、それらの充填材を、実施例１３のようにその側面に凹凸部を加工した。表１６に結果を示す。低濃度の原ガスにも、市販の板状セラミックス多孔体と同等の脱臭性能が、多孔質無機物質粒子の成形物でも得られた。
また、それら充填材の側面に凹凸部を加工することにより、脱臭性能が向上した。
【００７１】
【表１６】
【００７２】
【発明の効果】
本発明は次の効果を有する。
（１）難分解性である硫化メチルや二硫化メチルの除去率が高い。
（２）充填材が一体化されて作業性が向上する。
（３）圧密が防止でき、圧力損失が低く、処理ガス量の増加が可能である。
（４）低濃度臭気にも脱臭率が高く、従来必要であった仕上げ処理のための活性炭吸着設備が不要となる。
（５）低濃度臭気などには空塔速度が高くとれ、脱臭装置が小型化できる。
（６）充填層の閉塞が起これば、その閉塞個所の充填層を形成するモジュールを取り出し、短時間に閉塞の解消が可能である。
（７）充填材表面に凹凸部に加工することで、充填層の洗浄効果が高く、脱臭性能が向上できる。
【図面の簡単な説明】
【図１】縦型生物脱臭装置の概略図。
【図２】横型生物脱臭装置の概略図。
【図３】無機粒状充填材を充填したモジュールの概略図。
【図４】モジュール構成の充填材を充填層とする横型生物脱臭装置の概略図。
【図５】モジュール構成の充填材を充填層とする他の横型生物脱臭装置の概略図。
【図６】２塔式縦型生物脱臭装置の概略図。
【図７】２つの異なる性質の充填材を交互に配置したモジュール構造の概略図。
【図８】モジュール構造の充填材を充填層とする横型生物脱臭装置の概略図。
【図９】（Ａ）〜（Ｆ）は、側面に凸部又は凹部を形成した種々の加工物の斜視図。
【符号の説明】
１、１’、１”：縦型生物脱臭塔、２：横型生物脱臭装置、３、３’：充填層、４、４’：散水部、５、５’：受水部、６：悪臭ガス、７：処理ガス、８：循環液、９：補給水、１０：オーバーフロー、１１：充填したモジュール、１２：型枠、１３：板状セラミックス多孔体、１４：板状プラスチック発泡体又は板状繊維状充填材、ａ：気泡数の大きい多孔体又は粒径が大きい無機多孔体モジュール、ｂ：気泡数の大きい多孔体又は粒径が小さい無機多孔体モジュール、ｃ：ｂより気泡数の大きい多孔体又は粒径が大きい無機多孔体モジュール[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the biological deodorization of malodorous components, in particular, a deodorizing filler for biologically deodorizing malodorous gas generated from a sewage treatment plant, a human waste treatment plant, various factories, and a deodorizing method using the same. Equipment related.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Publication No. 6-91934
[Patent Document 2] JP-A-6-296821
As a deodorizing method to decompose and remove malodorous components in biologically malodorous gas, a packed tower type biological deodorizing method in which a malodorous gas is brought into contact with a packed bed to which sludge containing microorganisms are brought into contact, and a malodorous gas and microorganisms are used. A scrubber method of contacting the activated sludge suspension to be contained and an activated sludge deodorization method of blowing a malodorous gas into the activated sludge suspension have been put to practical use.
Above all, packed-bed type biological deodorization methods that can deodorize large quantities of malodorous gas with a compact deodorizing device due to low pressure loss in the packed bed and good gas-liquid contact with malodorous gas have become widespread. ing.
The packed tower type biological deodorizing apparatus includes a vertical type in which a packed bed is arranged in a vertical direction (Japanese Patent Publication No. Hei 6-91934) and a horizontal type in which the packed bed is horizontal to the floor of a building (Japanese Patent Laid-Open No. 6-296821). is there.
[0003]
FIG. 1 is a schematic diagram of a vertical biological deodorizing device, and FIG. 2 is a schematic diagram of a horizontal biological deodorizing device. In the vertical biological deodorizing apparatus, the malodorous gas 6 flows in from the lower part of the packed bed, and the processing gas 7 is discharged from the upper part of the packed bed through the packed bed 3. The circulating fluid 8 and the makeup water 9 are sprinkled from the upper portion of the packed bed to supply water to the microorganisms living in the packed bed 3 and to wash and discharge sulfate ions, which are decomposition products of odor components, from the packed bed. There is also a method in which an odor gas flows in from the upper portion of the packed bed, and the processing gas is discharged from the lower portion of the packed bed through the packed bed. In the horizontal biological deodorizer, the malodorous gas flows in from the packed bed side surface, and the processing gas is discharged from the packed bed side surface opposite to the inflow via the packed bed. Water is sprinkled from the top of the packed bed.
Conventionally, it is the shape and particle size of each filler that determine the deodorizing performance of the packed tower type biological deodorizing apparatus of any type.
The conventional packed tower type biological deodorizer uses granular materials such as plastic molded products, porcelain, ceramics, activated carbon and PVA granular granules, crushed shapes, scales, and fibrous fillers with a maximum diameter of 20 mm. These packing materials are packed irregularly in a packed bed space of a packed tower type biological deodorization apparatus.
[0004]
The conventional technology has the following problems.
(1) As for the granular, crushed, scale-like, and fibrous fillers, the packed layer formed by filling them gradually becomes more compact, the pressure loss of the packed layer increases, and the amount of processing gas decreases. The malodorous gas flows unevenly, and the deodorizing performance decreases.
(2) The work of filling a deodorizing device with a granular, crushed, scale-like, or fibrous filler is poor in workability and in the environment between works, such as generation of dust.
(3) Since the deodorizing device cannot be uniformly filled with the filler, the above-mentioned malodorous gas flows unevenly.
(4) When sulfate ions and the like, which are decomposition products of odor components, accumulate in the packed bed, the microorganisms die due to strong acidity, and the activity of the microorganisms stops due to an increase in salt concentration. In addition, microorganisms proliferate as the odor components are decomposed, and the packed layer is blocked by the proliferated microorganisms. In order to prevent these, water is regularly or continuously sprinkled on the packed bed to wash out sulfate ions, salts and proliferating microorganisms, thereby maintaining the habitat of the microorganisms in the packed bed. However, while soluble salts are easily removed from the packed bed by watering, growing microorganisms are difficult.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a biological deodorizing filler capable of solving the above-mentioned problems of the prior art, improving deodorizing performance, and reducing equipment costs, and a biological deodorizing method and apparatus using the same. I do.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized in that a plate-like porous body having a three-dimensional network structure and a communication space therein has a plurality of plate-like porous bodies having different numbers of bubbles arranged in a straight line per 25 mm. It is a filler for biological deodorization of offensive odor gas. In the deodorizing filler, the two types of plate-like porous bodies having different numbers of bubbles are such that the number of bubbles arranged in a straight line per 25 mm is a combination of 5 to 9 and 10 to 15, or 10 to 15 and 20 It is good to be a combination of two or more.
According to the present invention, there is provided a filler for biological deodorization of malodorous gas, comprising a plurality of modules in which inorganic particulate fillers having different particle diameters are separately filled in a mold having an arbitrary shape.
In the deodorizing filler, a plurality of plate-like porous bodies having a different number of bubbles, or a module of an inorganic particulate filler having a different particle size, are arranged alternately or in the order close to the gas inflow portion, the number of bubbles is reduced. The plate-shaped porous body having a larger number of bubbles or the module having a smaller particle size can be arranged in order from a small plate-shaped porous body or a module having a larger particle size.
[0007]
According to the present invention, there is provided a filler for biologically deodorizing a malodorous gas, comprising a plate-shaped ceramic porous body having a three-dimensional network structure and a communication space therein.
In the filler for deodorization, the plate-like ceramic porous body preferably has 5 to 50 bubbles arranged in a straight line per 25 mm.
Further, the present invention is characterized in that it has a module structure in which a plate-like porous ceramic body and a plate-like plastic foam or a plate-like fibrous filler having a communication space therein in a three-dimensional network structure are alternately arranged. It is a filler for biological deodorization of offensive odor gas.
Further, in the present invention, a filler for biological deodorization of malodorous gas characterized by comprising a molded product obtained by bonding granular or crushed porous inorganic material particles at a contact point to form a plate-shaped or columnar aggregate. It is what it was.
In the filler for deodorization, the molded product may have a plurality of recesses or a plurality of protrusions linearly formed on a side surface.
[0008]
Furthermore, in the present invention, a method for biologically deodorizing a malodorous gas, which comprises attaching microorganisms to a packed bed filled with the above-described deodorizing filler of the present invention and contacting it with a malodorous gas to biologically deodorize the same. It was done.
In the deodorizing method, when a plate-like porous ceramic body is used as the deodorizing filler, the filler is preferably used for at least the final packed layer.
Further, in the present invention, in a biological odor gas deodorizing apparatus having a filling layer and a means for spraying water on the filling layer, the filling layer is constituted by a filling layer filled with the above-described deodorizing filler of the present invention. The device is a biological deodorizing device for malodorous gas.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
The present invention relates to a filler for biological deodorization of malodorous gas, and a method and apparatus for deodorizing biologically by attaching microorganisms to a packed bed filled with the filler and contacting the gas with the malodorous gas.
The malodorous gas to be deodorized in the present invention is a gas containing hydrogen sulfide and at least one or more of ammonia, phenol, organic acids, aldehydes, and organic sulfur compounds such as methyl sulfide and methyl disulfide. Of course, hydrogen sulfide alone may contain at least one or more of the above-mentioned malodorous components other than hydrogen sulfide.
The biological deodorization of the present invention is a packed tower type biological deodorization method and apparatus having a packed bed.
There are two types of biological deodorizing devices, a vertical type and a horizontal type, and the present invention can be applied to both types. In the vertical biological deodorizing device, as shown in FIG. 1, the malodorous gas is directed upward or downward, and water is sprinkled in order to keep the packed bed in a wet state. Or an exchange. In the horizontal type, the odorous gas flows parallel to the floor of the building, and the flow direction of the odorous gas and watering is vertical.
[0010]
In the vertical deodorizing device, the height formed by stacking the filler is the height of the packed bed.
In the horizontal type deodorizer, the length of the packing material arranged side by side is the packed bed length (filled bed height). In addition, the filler is disposed on the cross section of the deodorization tower 1 by arranging a filler having an arbitrary size on the cross section of the deodorization tower 1 to form a cross section of the packed layer. The dimensions of the module other than the thickness are arbitrarily determined according to the shape and size of the cross section of the biological deodorization device.
In order to form a filler layer by distributing the filler in a block shape, avoid compaction such as granular or dice-like filler, and avoid high pressure loss parts that occurred partially in the filler layer. The serious problem of the malodorous gas drifting through the packed bed is eliminated. For this reason, the entire packed bed is uniformly and effectively used, so that the deodorizing performance is maintained at a high level.
Water is sprinkled on the upper portion of the packed layer in order to maintain the packed layer in a wet state, and the liquid used for watering may be the water that has passed through the packed layer and used again for watering. In addition, industrial water, biologically treated water and the like can be sprinkled directly from the upper portion of the packed bed. In sprinkling, as well as malodorous gas, the serious problem of drifting of sprinkling water is eliminated.
Watering may be continuous or intermittent with the watering time set in a certain range. Sprinkling amount is 0.1-5 liter / m per unit processing gas amount. 3 Gas, usually 3 l / m 3 -Gas.
The makeup water can be any of industrial water, biologically treated water and the like.
[0011]
FIG. 1 is a schematic diagram of a vertical type biological deodorizing apparatus, which explains biological deodorizing.
The microorganisms adhering to the packed bed 3 of the biological deodorization tower 1 are adjusted. Seed sludge such as activated sludge containing microorganisms is added to the water receiving section 5 and water is sprinkled from the water spraying section 4 by a circulation pump. The odorous gas 6 is introduced into the bottom of the deodorization tower to start deodorization. The processing gas 7 is discharged into the atmosphere from the upper part of the deodorization tower. If further deodorization is required, it is supplied to an activated carbon adsorption device. When the hydrogen sulfide removal rate becomes 80% or more, it can be determined that microorganisms capable of decomposing malodorous components have adhered to the packed bed, and the adaptation ends. After completion of the adaptation, a steady operation is performed by increasing the amount of the odorous gas. As the decomposition of the malodorous components progresses and sulfuric acid accumulates in the circulating water, the deodorizing effect decreases. To this end, the concentration of sulfuric acid in the circulating fluid or the like is reduced by replenishing the water receiving portion 5 with the make-up water 9 to maintain the activity of the microorganism.
[0012]
The filler of the present invention is a plate-like porous body having a three-dimensional network structure and a communication space therein, and a plurality of plate-like porous bodies having different numbers of bubbles arranged in a straight line per 25 mm. The plate-like porous body has a three-dimensional network structure, in which a plurality of spaces are configured by a skeleton, a communication space is provided inside, and a bad odor gas and water for sprinkling easily pass through.
The plate-shaped porous body has 5 to 30 bubbles on a straight line of 25 mm. The plate-like porous body includes a ceramic porous body, a sponge foam, and a fibrous filler.
As the plate-like porous ceramic body, a commercially available molten metal filter material, a filler for exhaust gas treatment, or a catalyst carrier for chemical synthesis can be used. As an example of the manufacturing method, a ceramic slurry is adhered to a synthetic resin body having a three-dimensional network structure and having a communication space therein, and the ceramic slurry is fired to obtain a plate-like ceramic porous body.
The sponge foam is a synthetic resin such as polypropylene or urethane foam, and a commercially available product used for a heat insulating material or the like can be used as the filler. The fibrous filler is a material in which a space is formed by chemical fibers, and a filler for an eliminator of a chemical cleaning and deodorizing apparatus can be used.
[0013]
The plate shape includes a rectangular parallelepiped and a columnar shape, and the thickness per sheet can be arbitrarily set. However, when a commercially available product is used in consideration of the cost of the filler, the thickness is 5 to 50 mm. Two or more types of modules formed of porous bodies having different numbers of air bubbles arranged in a line per 25 mm on a straight line are prepared and installed in a biological deodorization apparatus.
A plurality of plate-like porous bodies having different numbers of bubbles arranged in a line per 25 mm on a straight line are sequentially superposed to form a filling layer. The order in which the plate-shaped porous bodies having different numbers of bubbles are superposed can be arbitrarily determined. After stacking a plurality of plate-like porous bodies having the same number of bubbles, one or more plate-like porous bodies having different numbers of bubbles may be stacked.
When the number of bubbles arranged in a straight line per 25 mm is large, the surface area occupied by the inner surface of the bubbles is large, and the surface area of the entire porous body is large. Conversely, the smaller the number of bubbles, the smaller the cross-sectional area of the porous body.
By arbitrarily combining modules composed of porous bodies having different numbers of bubbles arranged in a straight line per 25 mm and forming a packed layer in a biological deodorizer, the number of bubbles arranged in a straight line per 25 mm is large, and the surface area of the porous body is increased. A module composed of a porous material having a large surface area has a large surface area and thus has a high deodorizing performance. By forming a filling layer having a different number of bubbles and a different surface area of the porous body in a plurality of sections in the height direction of the filling layer, it is possible to empirically prevent malodorous gas from drifting and improve deodorizing performance.
[0014]
Further, in the present invention, the two types of plate-like porous bodies having different numbers of bubbles arranged in a line per 25 mm on the straight line have 10 to 15 bubbles or 5 to 9 bubbles or 10 to 10 bubbles. It is preferable to use a combination in which the number of bubbles is 20 or more for ~ 15.
The number of bubbles can be arbitrarily combined within the above range. When a packed layer is formed by combining two types of plate-like porous bodies, the number of bubbles arranged in a line per 25 mm on a straight line of the plate-like porous body is 10, while the other plate-like porous body is 5 or 30 in number. It is preferred that A plate-like porous body having about 10 air bubbles is suitable for deodorizing a medium-concentration malodorous gas having a hydrogen sulfide concentration of several tens ppm or less because its surface area is large and pressure loss can be suppressed low. If it is expected that the malodorous gas concentration is high based on the plate-like porous body having about 10 bubbles, a plate-like porous body having about 5 bubbles is combined.
In order to sufficiently deodorize a low-concentration malodorous gas having a hydrogen sulfide concentration of 1 ppm or less, a plate-like porous body having about 10 bubbles and a plate-like porous body having 20 or more bubbles are combined.
[0015]
When the concentration of hydrogen sulfide is high, such as tens of ppm or more, the amount of microorganisms generated in the packed bed is large, so that about 5 bubbles are lined up per 25 mm on a linear plate-like porous body having large voids. Is desirable. When the concentration of hydrogen sulfide is moderate, such as several ppm, the amount of microorganisms generated in the packed bed is small. Approximately 15 is desirable. When the concentration of malodorous gas such as hydrogen sulfide concentration is 1ppm or less is low, and the activated carbon adsorption device is not installed as a finishing process after the biological deodorization device, the amount of microorganisms generated in the packed bed is small, and the process gas concentration is possible. Since it is necessary to reduce the temperature as much as possible, it is desirable to use a plate-shaped porous body having a large surface area and having 20 or more bubbles arranged in a straight line having a small gap per 25 mm.
The larger the number of cells arranged in a line per 25 mm on a straight line, the higher the deodorizing performance. However, since the voids are narrow, the pressure loss of the packed bed increases, and the deodorizing itself becomes difficult.
In order to reduce the pressure loss of the packed bed while maintaining a high deodorizing performance, a plate-like porous body having a different number of bubbles per 25 mm on a straight line is used.
[0016]
Further, the present invention is a deodorizing filler for malodorous gas comprising a plurality of modules in which inorganic particulate fillers having different particle diameters are separately filled in a mold having an arbitrary shape such as a rectangular parallelepiped or a column.
FIG. 3 shows a schematic diagram of a module 11 in which a rectangular mold 12 is filled with an inorganic particulate filler.
The inorganic particulate filler is filled into a mold of an arbitrary shape with a bulk. This mold is used as a module, and modules of inorganic particulate fillers having different particle sizes are arbitrarily combined and arranged in a deodorizing apparatus to form a packed layer.
The inorganic particulate filler is ceramic particles, carbide, or the like, and the particle size is 1 to 10 mm. The inorganic particulate filler may be of any shape.
The formwork may be entirely covered with a mesh shape such that the inorganic particulate filler does not spill, and the periphery thereof may be reinforced with plastic or FRP.
The mold is filled with an inorganic particulate filler having substantially the same particle size and an equal coefficient of 1.2 or less so as to prevent close packing with fillers having different particle sizes.
[0017]
In the present invention, two plate-shaped porous bodies having different numbers of air bubbles arranged in a straight line per 25 mm can be alternately provided as a filler for deodorization. The number of cells in the plate-like porous body can be arbitrarily combined. When a packed layer is formed by combining two types of plate-like porous bodies, the number of bubbles arranged in a line per 25 mm on a straight line of the plate-like porous body is 10, while the other plate-like porous body is 5 or 30 in number. It is preferred that A packing layer can be formed by alternately disposing a plate-like porous body having 10 bubbles and a plate-like porous body having 5 or 30 bubbles arranged in a line per 25 mm on a straight line. An arbitrary space can be provided between the plate-like porous bodies in consideration of the workability of replacing and disposing the plate-like porous bodies.
[0018]
Further, in the present invention, a module of two inorganic particulate fillers having different particle diameters can be alternately provided as a filler for deodorization. A module composed of an inorganic particulate filler having a particle diameter of 1 mm or less and a module composed of an inorganic granular filler having a particle diameter of 1 to 3 mm, or a module composed of an inorganic granular filler having a particle diameter of 1 to 3 mm and a particle diameter of 4 to A module made of a 20 mm inorganic particulate filler is combined to form a packed layer.
The particle diameter of the inorganic particulate filler is preferably 1 to 3 mm, and the other inorganic particulate filler is preferably 1 mm or less or 4 to 20 mm. In order to suppress the pressure loss of the packed bed, the number of modules of the inorganic particulate filler having a large particle size is increased to 2 to 10 per one inorganic particulate filler having a small particle size.
Furthermore, in the present invention, in order from a plate-like porous body having a small number of bubbles or a module having a large particle size to a module having a large number of bubbles, a plate-like porous body or a module having a small particle size is arranged in the order of proximity to the gas inflow portion. Can be a filler.
The filler for filling, which comprises a module of a plate-like porous body and an inorganic granular porous body, is used alone or in combination to fill the filling layer.
[0019]
FIG. 4 shows a schematic view of a horizontal biological deodorizing apparatus composed of a packed bed having a modular structure.
In the packed bed near the gas inlet, the load of the odor component of the malodorous gas is large, the amount of microorganisms growing in the decomposition process is increased, and the pressure loss is partially increased. In order to suppress an increase in pressure loss, a plate-like porous body having a small number of bubbles or a module having a large particle size is provided in the packed bed portion near the gas inflow portion. The odorous gas is treated as approaching the packed bed outlet, and pressure loss in the packed bed portion is suppressed. For this purpose, a plate-like porous body having a large number of bubbles or a module having a small particle size is provided at the packed layer outlet.
By disposing a plate-like porous body with a small number of air bubbles or a module with a large particle size in the packed bed near the gas inflow section, the water-sprinkling easily removes the proliferating microorganisms adhering to the packed bed, and is easily washed away. Can be kept low. On the other hand, a plate-like porous body having a large number of bubbles or a module having a small particle size, which is disposed at the outlet of the packed bed, has high contact efficiency with odorous gas and water sprinkling, and further reduces the odorous gas whose odor component concentration has been reduced. It is deodorized.
[0020]
Next, in the present invention, a filler in which a plurality of plate-like porous bodies having different numbers of air bubbles are alternately arranged, or a filler having a module structure in which a plurality of inorganic granular porous bodies having different particle diameters are alternately arranged was filled. An apparatus for deodorizing a malodorous gas composed of a packed bed will be described.
FIG. 5 is a schematic view of a horizontal biological deodorization apparatus including a packed bed having a modular structure. A packed layer in which a plurality of porous bodies having different numbers of bubbles are alternately arranged in the direction from the malodorous gas inflow direction to the outlet direction, or a module structure of a plurality of inorganic granular porous bodies having different particle sizes are alternately arranged, and the packed layer is formed. To form Sprinkling equipment will be provided above the packed bed. The sprinkling part has a filling layer upper area of 0.5 to 1 m so that water can be evenly sprayed on the upper part of the filling layer. 2 One sprinkling nozzle is arranged per contact. Sprinkling may be a circulating liquid from a water receiving unit or biologically treated water.
[0021]
The deodorizing device may be a horizontal type or a vertical type.
The horizontal type deodorizing device preferably has a structure in which each module or plate-like porous body is slid out of the deodorizing device and taken out. The clogged module or plate-like porous body is taken out of the packed bed and washed with high-pressure water or chemicals to eliminate the clogged state, and then returned to the packed bed. Since the time for stopping the deodorizing device is short, it is possible to prevent influences other than the deodorizing device and a decrease in deodorizing performance. Alternatively, the module or plate-like porous body near the inflow portion of the offensive odor gas and the module or plate-like porous body near the outlet portion can be exchanged. Microbes attached to the module or plate-like porous body near the outlet follow a declining trend because the module or plate-like porous body that has been replaced near the outlet has a low odor component load at the outlet. Finally, the blockage can be eliminated.
[0022]
Next, the filler made of a porous ceramic body having a three-dimensional network structure of the present invention and having a communication space therein will be described.
As the plate-shaped porous ceramic body having a three-dimensional network structure and a communication space therein, a commercially available molten metal filter material, a filler for exhaust gas treatment, or a catalyst carrier for chemical synthesis can be used. As an example of the manufacturing method, a ceramic slurry is adhered to a synthetic resin body having a three-dimensional network structure and having a communication space therein, and the ceramic slurry is fired to obtain a plate-like ceramic porous body.
The plate shape includes a rectangular parallelepiped and a columnar shape, and the thickness per sheet can be arbitrarily set. However, when a commercially available product is used in consideration of the cost of the filler, the thickness is 5 to 50 mm.
The plate-like ceramic porous body constitutes a filling layer by stacking a plurality of sheets. The height formed by stacking the plate-shaped ceramic porous bodies is the height of the filling layer. In addition, when the plate-shaped porous ceramic body is disposed on the cross section of the deodorization tower, an arbitrary size is spread over the cross section of the deodorization tower to form a packed layer cross section.
[0023]
In the plate-shaped porous ceramic body of the present invention, it is preferable that the number of bubbles arranged in a straight line per 25 mm is 5 to 50. If the number of bubbles arranged in a line per 25 mm on a straight line is large, the cross-sectional area of one space of the porous body is small, the surface area occupied by the space is large, and the surface area of the porous body is large. Conversely, the smaller the number of bubbles, the larger the cross-sectional area of one space of the porous body.
The larger the number of air bubbles arranged in a straight line per 25 mm, the larger the contact area with the odorous gas and the higher the deodorizing effect, but the clogging is likely to occur and the pressure loss of the packed bed increases.
When the number of bubbles arranged in a line per 25 mm on a straight line is 4 or less, the odor removing performance is low. If it exceeds 50, clogging is likely to occur, and the pressure loss of the packed bed increases.
Further, the plate-shaped porous ceramic body of the present invention is preferably used at least for a final packed layer. When the biological deodorizing apparatus is constituted by one packed tower and the packed tower has a plurality of packed beds, at least the final packed bed is filled with the plate-shaped porous ceramic body.
[0024]
In the case where the biological deodorizing apparatus is composed of a plurality of packed towers, the present invention covers a packed tower other than the final packed tower or the first packed tower.
In the first packed tower, it is not necessary to use the plate-shaped ceramic porous body of the present invention because hydrogen sulfide and ammonia which are easily removed biologically can be easily removed.
Of the malodorous components, ammonia, hydrogen sulfide, and methyl mercaptan can be easily removed by the packed bed near the inflow portion of the malodorous gas. However, since the removal rate of methyl sulfide or methyl disulfide is low, a plate-shaped ceramic porous body having high contact efficiency with an odorous gas is effective.
FIG. 6 shows a schematic diagram of a two-tower vertical biological deodorizing apparatus. The offensive odor gas 6 becomes the first tower processing gas 7 'via the packed bed 3' of the first tower deodorization tower 1 ', and the first tower processing gas 7' is led to the second tower deodorization tower 1 ". The gas is deodorized in the packed bed 3 and is discharged as the second tower processing gas 7. The final packed bed of the two-column vertical biological deodorization apparatus is the packed bed 3 of the second tower deodorizing tower.
[0025]
Further, the present invention is a filling filler having a module structure in which the plate-like porous ceramic body and the plate-like plastic foam or the plate-like fibrous filler are alternately arranged.
A commercially available filler formed by molding a synthetic resin such as polypropylene may be used as the plate-like plastic foam, but a sponge filler having a high deodorizing efficiency is preferable. The shape of the sponge filler has 5 to 30 cells (the number of cells on a straight line of 25 mm and the number of bubbles) and has a communication space therein.
In addition, the plate-like fibrous filler that can be used is formed by processing a synthetic fiber such as polyvinylidene chloride or a natural fiber such as peat moss into a plate shape. As the plate-like fibrous filler such as polyvinylidene chloride, those commercially available as mist separation of an eliminator can be used.
Natural fibers such as peat moss may be pressure-formed as they are in a plate shape, or may be entangled with a support of the chemical fiber.
[0026]
By alternately arranging the plate-like porous ceramics and the plate-like plastic foam, or the plate-like porous ceramics and the plate-like fibrous filler, the gap or filling between the plate-like porous ceramics in the height direction of the filling layer is obtained. The gap between the plate-shaped porous ceramics in the layer cross section is filled with a plate-shaped plastic foam or a plate-shaped fibrous filler, thereby suppressing the drift of the malodorous gas.
A module in which one to five plate-like ceramic foam bodies or one plate-like fibrous filler is superposed on one to five plate-like ceramic porous bodies in the height direction of the filling layer. A packed layer is formed using a plurality of these modules.
FIG. 7 is a schematic view of a module structure in which a plate-like porous ceramic body and a plate-like plastic foam or a plate-like fibrous filler are alternately arranged. This is a module structure in which a plate-like porous ceramic body and a plate-like fibrous filler are alternately provided one by one.
[0027]
A plate-like porous ceramic body and a plate-like plastic foam or a plate-like fibrous filler are provided in the gas flow direction. Further, it is possible to arrange so that a plate-like plastic foam or a plate-like fibrous filler is provided between the plate-like porous ceramics.
Each of the plate-like ceramic porous body, the plate-like fibrous filler, and the plate-like plastic foam can be entirely or laterally reinforced with a stainless or plastic net having an opening of about 100 mm.
Alternatively, the plate-like porous body and the plate-like plastic foam or the plate-like fibrous filler may be reinforced by being put into a mold. The frame portion may be reinforced with a plastic material or stainless steel, and the side portion may be a wire net or a plastic net.
[0028]
In addition, in the present invention, a deodorizing device for a malodorous gas, which is a horizontal biological deodorizing device having a packed layer made of the above-mentioned deodorizing filler having a modular structure, will be described.
FIG. 8 shows a schematic diagram thereof. Filling layers are composed of fillers A to F having a modular structure in which plate-like porous ceramics and plate-like fibrous fillers are alternately arranged one by one. The module structures A to F may be in close contact with each other, or a space may be provided at the boundary between the module structures A and B, B and C, and the like. Providing a space is advantageous in that the module whose microbial load has increased due to the propagation of the microbes is taken out of the apparatus and washed with a chemical such as water or hydrogen peroxide. Further, a plurality of plate-like ceramic porous bodies and a single plate-like fibrous filler may be alternately provided.
Watering is performed from the top of the module, and each module is provided with a series of watering units provided with a plurality of watering nozzles.
[0029]
Further, the filler of the present invention is a molded product obtained by bonding granular or crushed porous inorganic substance particles at a contact point to form a plate-like or columnar aggregate. In this molded product, a three-dimensional structure is formed by the individual particles, and a communication space is formed inside the molded product, so that the odorous gas and the water sprayed easily pass through.
Commercially available porous plate-shaped ceramics are limited in size, and when used as filler for actual equipment, they are joined together to form a single plate-shaped porous ceramic, or The smaller dimensions are laid in the packed bed. The granular or crushed porous inorganic material particles are commercially available ceramic particles, anthracite, sand, carbide, etc., and have a particle size of 1 to 20 mm. The porous inorganic material particles have substantially the same particle size with an equality coefficient of 1.2 or less so that close packing does not occur. When these particles are bonded to form a molded product, the size of the space of the molded product is 0.2 to 5 mm.
[0030]
There is no limitation on the method of bonding the porous inorganic substance particles. As an example of the bonding method, porous inorganic material particles are added to a slurry of about 10% of bentonite, an excess slurry is removed from the porous inorganic material particles by gravity separation, and then baked at 900 ° C. or more, and the particles are sintered. Are combined. A method can be adopted in which the chemical adhesive can be applied only to the portions where the porous inorganic material particles are in contact with each other, and the chemical adhesive does not adhere to the other surfaces of the porous inorganic material particles.
The shape of the molded article includes a rectangular parallelepiped and a columnar shape, and the thickness per sheet can be arbitrarily set. However, in consideration of workability and water dispersibility at the time of watering, the thickness is 5 to 50 mm. A plurality of moldings having different particle diameters of the porous inorganic substance particles are sequentially superposed to form a filling layer. The order of superposition can be determined arbitrarily. After a plurality of molded products having the same particle size are stacked, one or a plurality of molded products having different particle sizes may be stacked.
In consideration of the workability of replacing and disposing the plate-like porous body, an arbitrary space can be provided between the molded products.
[0031]
Further, in the present invention, a workpiece in which a plurality of recesses or a plurality of protrusions are linearly formed on the side surface of the plate-shaped porous body can be used as the filler.
The porous plate is preferably a porous ceramic. Since the ceramic porous body has a communication space therein and has a three-dimensional network structure, it is characterized by high contact efficiency between the odorous gas and microorganisms and low pressure loss. From the viewpoint of the deodorizing performance, it is preferable that the ceramic porous body has 5 to 30 bubbles arranged in a line per 25 mm on a straight line.
The shape of the concave portion or the convex portion can be arbitrarily determined, such as a hemispherical shape, a triangular pyramid shape, or a rectangular parallelepiped shape.
FIG. 9 shows a workpiece in which a plurality of recesses or a plurality of protrusions are linearly formed on a side surface of a plate-shaped porous body. The concave portions and the convex portions are on a continuous straight line. FIG. 9A shows a hemispherical recess formed on one side, and FIG. 9B shows a double-sided recess formed at the same position. FIG. 9C shows a hemispherical convex portion on one side, D shows a rectangular parallelepiped convex portion on one surface, E shows a rectangular parallelepiped concave portion on one surface, and F shows a triangular pyramid convex portion on one surface. It has been processed into.
[0032]
In the case of a horizontal deodorizing apparatus, as shown in FIG. 9, the malodorous gas flows perpendicularly to the plate-like porous body, and the circulating liquid of water spray flows parallel to the plate-like porous body. The sprinkled circulating fluid mainly flows into the concave portion, and if the workpiece is a convex portion, the circulating fluid flows into the concave portion formed by the convex portion, and the salts and the microorganisms accumulated in the packed layer are easily washed out of the packed layer. It is. Even if a large amount of the circulating liquid is sprayed on the packed bed, it is quickly discharged. Therefore, even during operation, there is no sudden pressure loss due to the spraying of the packed bed, and there is no stoppage of the flow of the offensive odor gas due to the increased pressure loss. By spraying a large amount of the circulating fluid, the proliferating microorganisms that are difficult to remove are easily discharged from the packed bed. By arbitrarily changing the amount of water in the circulating fluid, optimally growing microorganisms can be removed. The concave and convex portions formed on the side surface of the plate-shaped porous body, the surface where the odorous gas and the circulating liquid are in contact with each other serve as a drainage channel for the circulating liquid, and the circulating liquid and water sprinkled from the packed bed can be easily formed. Is discharged. As a result, the pressure loss of the packed bed can be kept low.
In the case of the vertical deodorization tower, the flow of the malodorous gas is the same as in the horizontal type, but the flow direction of the sprinkling water is perpendicular to the plate-like porous body.
[0033]
Irregularities may be provided on one side of one work piece or on both sides. Further, the position of the uneven portion on one side may be shifted. There is no limitation on the depth of the concave portion or the height of the convex portion, but it is generally several to 30 mm. If it is less than a few mm, the plate-shaped porous body originally has such irregularities, and the effect of the irregularities is not obtained. If it exceeds 30 mm, the strength of the workpiece is reduced.
In the arrangement of the uneven portions, the total length of the frontage of the concave portion or the convex portion is 50 to 20% of the length of one side of the workpiece on which the concave portion or the convex portion is provided. From the arrangement, 50% is the maximum, and if it is less than 20%, the amount of watering cannot be eliminated quickly.
A plate-like porous body having about 10 air bubbles is suitable for deodorizing a medium-concentration malodorous gas having a hydrogen sulfide concentration of several tens ppm or less because its surface area is large and pressure loss can be suppressed low. When the concentration of malodorous gas such as hydrogen sulfide concentration of several tens of ppm or more is high, the amount of microorganisms generated in the packed bed is large, so that a plate-like porous body having large voids, about 5 bubbles in a straight line per 25 mm Is desirable. When the concentration of hydrogen sulfide is an odor gas concentration of several ppm and the concentration is moderate, the amount of microorganisms generated in the packed bed is small. Approximately 15 is desirable.
[0034]
Further, in the present invention, a workpiece in which a plurality of recesses or a plurality of protrusions are linearly formed on the side surface of the assembly can be used as the filler.
An uneven portion may be provided on one surface of a single workpiece through which the offensive odor gas passes, or may be provided on both surfaces. Further, the position of the uneven portion on one side may be shifted. There is no limitation on the depth of the concave portion or the height of the convex portion, but it is generally 10 to 30 mm. If it is less than 10 mm, the original aggregate has such irregularities, and the effect of the irregularities is not obtained. If it exceeds 30 mm, the strength of the workpiece is reduced.
Further, the uneven portion on one surface through which the offensive odor gas passes may be arranged in the packed bed so as to be in the inflow direction or the outflow direction of the offensive odor gas.
In the arrangement of the uneven portions, the total length of the frontage of the concave portion or the convex portion is 50 to 20% of the length of one side of the workpiece on which the concave portion or the convex portion is provided. From the arrangement, 50% is the maximum, and if it is less than 20%, the amount of watering cannot be eliminated quickly.
[0035]
Further, according to the present invention, a biological deodorizing apparatus having a packed bed provided with the above-mentioned processed product can be provided.
This will be described with reference to a schematic diagram of the horizontal biological deodorization apparatus shown in FIG.
The filler is a plate-shaped ceramic porous body having a plurality of recesses or a plurality of protrusions formed on a side surface thereof or a molded article of porous inorganic material particles having a plurality of recesses or a plurality of protrusions formed on a side surface thereof. A filling layer is formed by filling materials at a certain interval with one another. Since it is a horizontal type deodorizing device, the filling layer is provided so that the inflow direction of the offensive odor gas is perpendicular to the uneven portion on the side surface. The processing gas is exhausted from a direction opposite to the inflow direction. Sprinkling equipment will be provided above the packed bed. The sprinkling part has a filling layer upper area of 0.5 to 1 m so that water can be evenly sprayed on the upper part of the filling layer. 2 One sprinkling nozzle is arranged per contact.
[0036]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples.
Example 1
The horizontal biological deodorizer of Fig. 2 has a packed bed cross-sectional area of 0.36m. 2 The experiment was conducted using a packed bed height (distance from the gas inlet of the packed bed to the outlet of the packed bed) of 1 m.
The composition of the raw gas is 5 ppm for hydrogen sulfide, 2 ppm for methyl mercaptan, and 1 ppm for methyl sulfide.
The plate-shaped ceramic porous body has a three-dimensional network structure of 0.6 m in length and 0.1 m in thickness, and a ceramic slurry of 90% or more alumina oxide having a particle diameter of 10 μm is attached to a urethane synthetic resin body having a communication space therein. This was baked at 900 ° C. for 1 hour to produce the product. The number of bubbles in the plate-like porous body was set arbitrarily to the number of bubbles in the synthetic resin body having a three-dimensional network structure and a communication space therein.
In the direction of the raw gas inflow, 2 to 5 plate-like ceramic porous bodies having 5 bubbles in a straight line per 25 mm, 5 to 8 plate-like ceramic porous bodies having 15 bubbles in the outlet direction, Alternatively, a packed layer is formed by combining 2 to 5 plate-like ceramic porous bodies having 15 bubbles in the direction of the raw gas inflow section and 5 to 8 plate-like ceramic porous bodies having 30 bubbles in the outlet direction. Was formed.
[0037]
The experimental conditions were a superficial tower speed of 500 h. -1 The amount of water sprayed per unit processing gas amount is 3 liter / m 3 , Continuous watering, gas temperature 20 ~ 25 ° C, circulating water sludge concentration several tens mg / l (initial concentration: about 2000mg / l, circulating water pH 2 ~ 4, biological treatment water sand filtration water as makeup water After adjusting the sludge concentration of the circulating water to about 2000 mg / l, the circulating water was continuously sprinkled on the packed bed while continuously passing the odorous gas. It became 90%, and the adaptation was completed.
Table 1 shows the odor component removal rate and pressure loss of the packed bed 2 weeks after the adaptation. Rather than using a plate-like porous ceramic body having the same number of cells as a packed layer, using a plate-like porous ceramic body with a different number of bubbles results in lower pressure loss in the packed layer, a higher removal rate of odor components, and deodorization. The performance was good.
[0038]
[Table 1]
[0039]
Example 2
In the experimental apparatus of Example 1, two plate-like porous bodies having different numbers of bubbles were alternately provided to form a packed layer, and an experiment was performed in the same manner as in Example 1.
From the raw gas inflow portion to the outlet direction, one plate-like porous ceramic body having 5 bubbles and a number of 15 bubbles arranged in a line per 25 mm in the straight line of Example 1 and a plate-like porous ceramic body having 15 bubbles are provided. A packing layer was formed by alternately combining one plate-like porous ceramic body having 15 bubbles in Example 1 and 1 to 4 plate-like ceramic porous bodies having 30 bubbles in Example 1. Table 2 shows the odor component removal rate and the pressure loss of the packed bed.
When the plate-shaped porous ceramics having different numbers of cells were alternately provided in the packed bed, the pressure loss of the packed bed was small, the removal rate of the odor component was high, and the deodorizing performance was good.
[0040]
[Table 2]
[0041]
Example 3
Modules of inorganic particulate fillers having different particle sizes were alternately arranged in the experimental apparatus of Example 1 to form a packed layer, and an experiment was performed in the same manner as in Example 1.
The inorganic particulate filler is produced by granulating dust collected from a casting process into a predetermined size and firing at about 900 ° C. in an air atmosphere, and classifying the fired product. The particle size of the inorganic particulate filler is 1 mm, 3 mm, and 10 mm, and the uniformity coefficient is 1.2 for each.
An inorganic particulate filler having a particle diameter of 1 mm was filled into a mesh formed of nylon fiber threads having an aperture of 1 mm in an FRP rectangular parallelepiped mold having a width of 0.1 m and a length of 0.6 m, and this was used as a module. did.
The inorganic particulate filler having a particle diameter of 3 mm is filled in a form covered with a mesh of nylon fiber having an aperture of 3 mm, and the inorganic particulate filler having a particle diameter of 10 mm is a nylon fiber thread having an aperture of 5 mm. Filled into mesh-covered formwork.
[0042]
2 to 5 inorganic particulate filler modules having a particle diameter of 3 mm in the direction of the raw gas inflow section, 5 to 8 inorganic granular filler modules having a particle diameter of 1 mm in the exit direction, or 10 mm in the direction of the raw gas inflow section 2 to 5 inorganic particulate filler modules, and 5 to 8 inorganic particulate filler modules having a particle size of 3 mm in the outlet direction were combined to form a packed layer.
Table 3 shows the removal rate of the odor component and the pressure loss of the packed bed about 6 weeks after the adaptation.
Combining inorganic particulate filler modules of different particle sizes reduces the pressure loss of the packed bed, increases the removal rate of odor components, and deodorizes, rather than using only inorganic particulate filler modules of the same particle size as the packed layer. The performance was good.
[0043]
[Table 3]
[0044]
Example 4
In the experimental apparatus of Example 1, a packed layer was formed by alternately disposing modules of two inorganic particulate fillers having different particle sizes, and an experiment was performed in the same manner as in Example 1.
From the raw gas inflow section toward the outlet direction, 1 to 4 inorganic granular filler modules having a particle diameter of 1 mm are alternately provided for one inorganic granular filler module having a particle diameter of 3 mm of Example 3. A packing layer was formed by alternately combining one to four inorganic particulate filler modules having a particle diameter of 3 mm with respect to one inorganic particulate filler module having a particle diameter of 10 mm.
Table 4 shows the odor component removal rate and the pressure loss of the packed bed.
When the inorganic particulate filler modules having different particle diameters were alternately provided in the packed bed, the pressure loss of the packed bed was small, the odor component removal rate was high, and the deodorizing performance was good.
[0045]
[Table 4]
[0046]
Example 5
In the experimental apparatus of Example 1, a plate-like porous body having a small number of bubbles or two inorganic particulate filler modules having a large particle size were arranged in this order from the gas inflow section to form a packed layer, and the packed layer was formed in the same manner as in Example 1. Experimented.
The plate-like porous body is composed of 2 to 4 plate-like ceramic porous bodies each having 5 bubbles in a line per 25 mm in a straight line in Example 1 from the raw gas inflow section toward the outlet direction. The filled layer was formed with 2 to 4 plate-like ceramic porous bodies having 15 pieces of ceramics and 2 to 4 plate-like ceramic porous bodies having 30 bubbles.
The inorganic particulate filler module is composed of two to four inorganic particulate filler modules having a particle diameter of 10 mm in Example 3 and two to four inorganic particulate filler modules having a particle diameter of 3 mm in Example 3 from the raw gas inflow portion. A packed layer was formed with 2 to 6 inorganic particulate filler modules having a particle size of 1 mm.
Tables 5 and 6 show the odor component removal rate and the pressure loss of the packed bed.
By disposing a plate-like porous material with a small number of bubbles and an inorganic particulate filler module with a large particle size in the packed bed in order from the gas inflow section, the pressure loss of the packed bed is small, the odor component removal rate is high, and the deodorizing performance is high. Was good.
[0047]
[Table 5]
[0048]
[Table 6]
[0049]
Example 6
The superficial velocity was changed to 1000 h by changing the raw gas concentration in Example 1 to a thinner one. -1 , The amount of water sprayed per unit processing gas amount is 3 liter / m 3 The experiment was carried out in the same manner as in Example 2 with intermittent watering for 5 minutes per hour. The composition of the raw gas is 0.5 ppm for hydrogen sulfide, 0.1 ppm for methyl mercaptan, 0.05 ppm for methyl sulfide, and 0.05 ppm for methyl disulfide.
Table 7 shows the results. Even with a low-concentration odor, high deodorization performance can be maintained by forming a packed layer in which two plate-like porous bodies having different numbers of bubbles are alternately arranged. There is no need for a subsequent activated carbon adsorption device.
[0050]
[Table 7]
[0051]
Example 7
Two inorganic particulate filler modules with different particle sizes from Example 3 were deployed in a packed bed as in Example 4 and tested as in Example 6.
Even with a low-concentration odor, a high deodorizing performance can be maintained by forming a packed bed in which two inorganic particulate filler modules having different particle sizes are alternately arranged.
Table 8 shows the results.
In the production of a plate-like porous body, it is difficult to obtain a plate-like porous body of an arbitrary size, and the production cost is high. However, by making an inorganic particulate filler such as ceramics into a module, an expensive plate-like porous body is produced. The same deodorizing performance was obtained.
[0052]
[Table 8]
[0053]
Example 8
The deodorizer of FIG. 1 has a packed bed cross-sectional area of 0.36 m 2 An experiment was performed using a packed bed height of 1 m.
The composition of the raw gas is 10 ppm for hydrogen sulfide, 3 ppm for methyl mercaptan, and 1 ppm for methyl sulfide. The sponge filler was a urethane foam having 5 to 25 bubbles arranged in a line per 25 mm on a straight line, and 10 sheets each having a length and width of 0.6 m and a thickness of 10 cm were stacked. As for the plate-like porous ceramic body, a filling layer was formed by using ten sheets having the same shape as the sponge filler. As the fibrous filler, a commercially available filler for a eliminator (thickness of fiber: 0.3 mm, made of polyvinylidene chloride) having a thickness of 20 mm, which was cut into a length of 0.6 m and a width of 20 m, was used.
[0054]
The experimental conditions were a superficial tower speed of 500 h. -1 , Water spray amount per unit processing gas amount is 3 liter / m 2 , Continuous watering, gas temperature of 20 to 25 ° C, circulating water sludge concentration of several tens mg / l (initial concentration; about 2000 mg / l), circulating water pH of 2 to 4, and biologically treated water as makeup water.
After adjusting the sludge concentration of the circulating water to about 2000 mg / l, the circulating water was continuously sprinkled on the packed bed while continuously passing the odorous gas. After about one week, the removal rate of hydrogen sulfide became 90%, and the adaptation was completed.
Table 9 shows the odor component removal rate and the pressure loss of the packed bed two weeks after the adaptation. The deodorizing performance of the plate-shaped porous ceramic body was good.
When the number of cells arranged in a line per 25 mm on a straight line increased, the pressure loss of the sponge filler showed a higher value than that of the plate-shaped ceramic porous body.
[0055]
[Table 9]
[0056]
Example 9
An experiment was conducted in the same manner as in Example 8 using the two-tower vertical biological deodorization apparatus of FIG. 6 in which the deodorization towers of Example 8 were arranged in series. The difference between the experimental conditions is that the filler in the first column is the plate-like sponge filler having 15 bubbles arranged in a straight line per 25 mm in Example 8, and the filler in the second column is the plate in Example 1. It is a sponge filler or a plate-like porous ceramic body.
Table 10 shows the odor component removal rates in the second tower after 6 weeks from the end of the adaptation.
[0057]
[Table 10]
[0058]
Example 10
The superficial gas velocity was changed to 1500 h by changing the raw gas concentration in Example 1 to a thinner one. -1 , The amount of water sprayed per unit processing gas amount is 3 liter / m 3 The experiment was carried out in the same manner as in Example 1 with intermittent watering for 5 minutes per hour. The composition of the raw gas is 0.5 ppm for hydrogen sulfide, 0.1 ppm for methyl mercaptan, and 0.05 ppm for methyl sulfide.
Table 11 shows the results. Even with a low concentration odor, the deodorizing performance can be maintained high by using the plate-shaped ceramic porous body as the filler. There is no need for a subsequent activated carbon adsorption device.
[0059]
[Table 11]
[0060]
Example 11
With the deodorizing device of FIG. 8, the packed bed cross-sectional area is 0.36 m 2 An experiment was performed in the same manner as in Example 8 using the raw gas of Example 8 using a packed bed length of 1 m.
The filling layer was formed by filling the module composed of the plate-shaped ceramic porous body of Example 8 alone or the sheet-shaped ceramic porous body and one sponge filler.
For a single plate-shaped ceramic porous body having a length and width of 0.6 m, a thickness of 10 cm, and 5 to 25 cells arranged in a line per 25 mm on a straight line, a urethane foam having 10 cells arranged in a line per 25 mm on a straight line is used. One piece of sponge filler, 0.6 m in length and 10 cm in thickness, was layered and stored in a plastic formwork with a mesh of 20 mm in mesh to make a set of modules. The dimensions of one set of modules were about 0.6 m in length and width, and 20 cm in thickness.
After about one week, the removal rate of hydrogen sulfide became 90%, and the adaptation was completed.
About 3 weeks after acclimation, the removal rate of methyl sulfide was 90%. Table 12 shows the odor component removal rate and the pressure loss of the packed bed after a lapse of two weeks. The deodorizing performance of the plate-shaped porous ceramic body was good.
The module composed of the plate-shaped porous ceramic body and the sponge filler one by one has high deodorizing performance, and the pressure loss is lower than that of the plate-shaped porous ceramic body alone.
[0061]
[Table 12]
[0062]
Example 12
The horizontal biological deodorizer of Fig. 2 has a packed bed cross-sectional area of 0.36m. 2 The experiment was conducted using a packed bed height (distance from the gas inlet of the packed bed to the outlet of the packed bed) of 1 m. The composition of the raw gas is 1 ppm of hydrogen sulfide, 1 ppm of methyl mercaptan, and 1 ppm of methyl sulfide.
Porous inorganic material particles are produced by granulating dust collected from the casting process into a predetermined size, firing at about 900 ° C in an air atmosphere, and classifying the fired product. is there. The particle diameters of the porous inorganic substance particles are 1 mm, 3 mm, and 10 mm, and their uniformity coefficients are 1.2. To 100 parts by weight of these porous inorganic material particles, 100 parts by weight of a ceramic slurry having a particle size of 10 μm and 90% or more of alumina oxide were mixed, and a gravity separation block-shaped mold (0.6 m square, having a thickness of 0.1 mm) was used. 1m) and fired again at about 900 ° C. in an air atmosphere to obtain a molded product.
A conventional and commercially available plate-shaped ceramic porous body is a urethane synthetic resin body having a three-dimensional network structure of 0.6 m in length and 0.1 m in thickness and having a communicating space therein, and 90% alumina oxide having a particle diameter of 10 μm. The above-mentioned ceramic slurry was adhered, and the resultant was baked at 900 ° C. for 1 hour to produce a ceramic slurry. The number of bubbles in the plate-shaped porous body is 25 (pore diameter is about 1 mm) and 13 (pore diameter is about 2 mm) arranged in a straight line per 25 mm.
[0063]
The molded article or the plate-like porous ceramic body of the present invention was provided in the direction of the raw gas inflow portion to form a packed layer.
The experimental conditions were a superficial tower speed of 500 h. -1 , Water spray amount per unit processing gas amount is 3 liter / m 3 , Continuous watering, gas temperature 20-25 ° C, circulating fluid sludge concentration tens of mg / l (initial concentration: about 2000 mg / l), circulating water pH 2-4, and biological filtration water sand filtration as makeup water Water was used. After adjusting the sludge concentration of the circulating water to about 2000 mg / l, the circulating water was continuously sprinkled on the packed bed while continuously passing the odorous gas. After about one week, the removal rate of hydrogen sulfide became 90%, and the adaptation was completed.
Table 13 shows the odor component removal rate and the pressure loss of the packed bed after 4 weeks. The filler of the inexpensive porous inorganic material particle molded product had the same deodorizing performance as a commercially available expensive plate-like ceramic porous body.
[0064]
[Table 13]
[0065]
Example 13
A raw gas having a composition of 1 ppm of hydrogen sulfide and 10 ppm of acetaldehyde was biologically deodorized by the experimental apparatus of Example 12. The circulating liquid was neutralized to pH 6 to 8 with 10% sodium hydroxide solution.
About 10 days after the start of the experiment, the removal rate of hydrogen sulfide and aldehyde became 90%, and the adaptation was completed. After adaptation, the rate of water spray per unit processing gas amount is 10 l / m, once a day. 3 The packed bed was washed by sprinkling water for about 10 minutes. It shows the pressure loss of the packed bed and the removal rate of the odor component about 3 weeks after the completion of the adaptation.
[0066]
The plate-shaped ceramic porous body of Example 12 in which the number of cells arranged in a line per 25 mm on a straight line is 13 was processed into the shape of A or C in FIG. All were packed layers. The shape of the filler in the semicircular concave portion in FIG. 9A is obtained by processing a semicircular concave portion having a diameter of 3 cm into a 0.6 m shape at intervals of 5 cm. The filling material of the semicircular convex portion is obtained by processing a semicircular convex portion having a diameter of 3 cm into a 0.6 m shape at intervals of 5 cm in the shape of C in FIG. 9. Table 14 shows the results. The plate-like ceramic porous body having no irregularities had a low effect of washing the packed layer, insufficient peeling of the growing microorganisms, a high pressure loss in the packed layer, and a slightly low odor component removal rate. As the deodorization is continued, this tendency is further increased because the growth microorganisms are not sufficiently removed. In sprinkling for cleaning, the flow rate of the raw gas temporarily decreased. The plate-shaped porous ceramic body having the irregularities has a sufficient cleaning effect and a high deodorizing performance, and in particular, the porous ceramic body having unevenness on both surfaces has a high deodorizing effect.
[0067]
[Table 14]
[0068]
Example 14
The same processing as in Example 13 was performed on the side of a molded product of the porous inorganic substance particles having a particle diameter of 3 mm and a uniformity coefficient of 1.2, a 0.6 m square, and a thickness of 0.1 m of Example 12, and The experiment was performed similarly. Table 15 shows the results.
The molded product of the porous inorganic substance particles having no irregularities had a low effect of washing the packed bed, insufficient peeling of the proliferating microorganisms, a high pressure loss in the packed bed, and a slightly low odor component removal rate. The molded product of the porous inorganic substance particles having the irregularities has a sufficient washing effect and high deodorizing performance, and particularly has a high deodorizing effect of the molded product of the porous inorganic substance particles having irregularities on both surfaces.
[0069]
[Table 15]
[0070]
Example 15
The raw gas concentration in Example 12 was changed to a thinner one, and the superficial velocity was 300 h. -1 , The amount of water sprayed per unit processing gas amount is 3 liter / m 3 The experiment was carried out in the same manner as in Example 1 with intermittent watering for 5 minutes per hour. The composition of the raw gas is 0.5 ppm for hydrogen sulfide, 0.1 ppm for methyl mercaptan, 0.05 ppm for methyl sulfide, and 0.05 ppm for methyl disulfide.
The molded article of the porous inorganic substance particles of Example 12 and the plate-shaped porous ceramic body of Example 12 were used as the filler. In addition, these fillers were processed to have uneven portions on the side surfaces as in Example 13. Table 16 shows the results. Even with a low-concentration raw gas, a deodorizing performance equivalent to that of a commercially available plate-like ceramic porous body was obtained with a molded product of porous inorganic substance particles.
Further, by processing the irregularities on the side surfaces of these fillers, the deodorizing performance was improved.
[0071]
[Table 16]
[0072]
【The invention's effect】
The present invention has the following effects.
(1) High removal rate of hardly decomposable methyl sulfide and methyl disulfide.
(2) The workability is improved by integrating the filler.
(3) Consolidation can be prevented, pressure loss is low, and the amount of processing gas can be increased.
(4) The deodorization rate is high even for low-concentration odors, which eliminates the need for activated carbon adsorption equipment for finishing, which was conventionally required.
(5) The superficial velocity can be increased for low-concentration odors and the like, and the deodorizing device can be downsized.
(6) If the clogging of the packed layer occurs, the module forming the packed layer at the clogged portion is taken out, and the clogging can be eliminated in a short time.
(7) By processing the filler surface into irregularities, the effect of cleaning the filling layer is high, and the deodorizing performance can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic view of a vertical biological deodorizing apparatus.
FIG. 2 is a schematic diagram of a horizontal biological deodorizing device.
FIG. 3 is a schematic diagram of a module filled with an inorganic particulate filler.
FIG. 4 is a schematic view of a horizontal biological deodorizing apparatus using a packing material having a modular structure as a packing layer.
FIG. 5 is a schematic view of another horizontal biological deodorization apparatus using a packing material having a modular configuration as a packing layer.
FIG. 6 is a schematic view of a two-tower vertical biological deodorizing apparatus.
FIG. 7 is a schematic view of a module structure in which fillers having two different properties are alternately arranged.
FIG. 8 is a schematic view of a horizontal biological deodorizing apparatus using a packing material having a modular structure as a packing layer.
FIGS. 9A to 9F are perspective views of various workpieces having convex portions or concave portions formed on side surfaces.
[Explanation of symbols]
1, 1 ', 1 ": vertical biological deodorization tower, 2: horizontal biological deodorizer, 3, 3': packed bed, 4, 4 ': water spraying part, 5, 5': water receiving part, 6: malodorous gas , 7: process gas, 8: circulating liquid, 9: make-up water, 10: overflow, 11: filled module, 12: form, 13: plate-like ceramic porous body, 14: plate-like plastic foam or plate-like fiber Filler, a: a porous body having a large number of bubbles or an inorganic porous body module having a large particle diameter, b: a porous body having a large number of bubbles or an inorganic porous body module having a small particle diameter, c: a porous body having a larger number of bubbles than b Or inorganic porous module with large particle size
