JP2004049971A - Phosphorus adsorbent and its production method, phosphorus recovering method, method for treating phosphorus adsorbent, and method for treating water containing phosphorus component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove and effectively use phosphorus components contained in water to be treated and to safely and effectively use general waste and industrial waste. <P>SOLUTION: The water to be treated containing the phosphorus components (for example, separated water obtained by solid-liquid separation in a final precipitation basin) is supplied to a phosphorus recovery tank 1 storing a phosphorus adsorbent containing alkaline components positioned on its surface and its hole surfaces and carbon components, and the phosphorus components in a liquid phase are adsorbed and removed. In the tank 1, adsorption cartridges are provided attachably/detachably. In the adsorption cartridge, the phosphorus adsorbent is housed in a water permeable member. The phosphorus adsorbent is obtained by making a raw material containing the alkaline components and the carbon components porous by pyrolyzing it on indirect heating. The general waste and the industrial waste are used as the raw material. <P>COPYRIGHT: (C)2004,JPO

Description

【００３０】
表１において、試料１は、ＢＲ（ポリブタジエンゴム）とＣＳＭ（クロロスルホン化ポリエチレンゴム）とＣＲ（クロロプレンゴム）とＣＢ（カーボンブラック）とを含有するゴムを原料とし、これを加熱処理して得た炭化物である。
【００３１】
試料２は、ＢＲとＥＰＤＭ（エチレンプロピレン系ゴム）とＣＢとを含有するゴムを原料とし、これを加熱処理して得た炭化物である。
【００３２】
試料３は、ＢＲとＥＰＤＭとＣＢとを含有するゴムを原料とし、これを加熱処理して得た炭化物である。
【００３３】
試料４は、ＢＲとＣＢとを含有するゴムを原料とし、これを加熱処理して得た炭化物である。
【００３４】
試料５は、ＢＲを含有するゴムを原料とし、これを加熱処理して得た炭化物である。
【００３５】
図９は、試料１のリン成分の吸着性性能を示した特性図である。ここでは、リン酸溶液５００ｍｌに対して、０．２ｇ、０．５ｇ、１ｇの試料１を添加した場合のリン酸残留濃度の経時的変化を示す。かかる結果によると、リン成分の除去性能は、試料１の添加量に依存し、特に、２０ｍｇ／ｌのリン酸溶液５００ｍｌに対し１ｇ以上添加すれば、短時間で且つリン酸除去率はほぼ１００％となることが確認できる。
【００３６】
図１０は、試料２のリン成分の吸着性性能を示した特性図である。ここでは、リン酸溶液５００ｍｌに対して、０．１ｇ、０．２ｇ、０．５ｇ、１ｇの試料２を添加した場合のリン酸残留濃度の経時的変化を示す。かかる結果によると、試料１と同様に、リン成分の除去性能は、試料２の添加量に依存し、特に、２０ｍｇ／ｌのリン酸溶液５００ｍｌに対し１ｇ以上添加すれば、短時間で且つリン酸除去率がほぼ１００％となることが確認できる。
【００３７】
図１１は、試料３のリン成分の吸着性性能を示した特性図である。ここでは、リン酸溶液５００ｍｌに対して、５ｇの試料３を添加した場合のリン酸残留濃度の経時的変化を示す。かかる結果によると、溶液と試料の接触時間が約１０分以内で、良好なリン吸着性能（除去率約１００％）が得られていることが確認できる。
【００３８】
図１２は、試料４のリン成分の吸着性性能を示した特性図である。ここでは、リン酸溶液５００ｍｌに対して、５ｇの試料４を添加した場合のリン酸残留濃度の経時的変化を示す。かかる結果よると、リン酸除去率は約２０％に留まっている。表１の成分分析結果から明らかように、試料４は、Ｃａ成分を含むもののその含量は試料１〜３と比較して少量であり、リン成分の吸着効果は試料１〜３と比較して劣ったものとなった。
【００３９】
図１３は、試料５のリン成分の吸着性性能を示した特性図である。ここでは、リン酸溶液５００ｍｌに対して、５ｇの試料５を添加した場合のリン酸残留濃度の経時的変化を示す。かかる結果よると、試料５のリン酸除去率は１０％未満に留まっている。表１の成分分析結果から明らかなように、試料５は、Ｃａ成分を含んでいないことから、リン成分の吸着効果は試料１〜３と比較して劣ったものとなった。
【００４０】
以上の実験結果に基づき創出された本発明の実施形態について説明する。
【００４１】
（実施形態１）
図１は、本発明に係るリン吸着材を使用したシステム構成の概略図で、下水処理施設に適用した場合のものである。
【００４２】
ここでは、活性汚泥法に基づく下水処理施設に、図３で示す本発明の吸着材を備えたリン回収槽１を設置したものである。
【００４３】
図において、最初沈殿池では、導入した汚水を固液分離処理する。生物反応槽では、最初沈殿池で得た固液分離水を活性汚泥と接触させて、液相中の有機物及び窒素成分を生物学的に分解除去する。嫌気発酵槽では、生物反応処理水を嫌気性発酵によって、活性汚泥微生物群の細胞内からリン成分をリン酸の形態で溶出している。最終沈殿池は、嫌気発酵処理水を固液分離処理する。汚泥濃縮槽は、最初沈殿池と最終沈殿池で分離した汚泥を濃縮する。最終沈殿池及び汚泥濃縮槽で得た分離水はリン回収槽１に移送している。分離水は、嫌気性発酵槽、最終沈殿池及び汚泥濃縮槽における嫌気作用によって、リン酸に富んだものとなっている。分離水は、リン回収槽１内に導入されると、一定の滞留時間の下、本発明のリン吸着材と接触する。このとき、分離水中のリン酸は、当該吸着材によって吸着除去される。処理水は、河川等に自然水系に放流される。リン成分を吸着した吸着材は、リン回収槽１から回収された後、図６、図７または図８記載の加熱処理施設に供される。尚、汚泥濃縮槽で濃縮した汚泥は、本発明のリン吸着材の原料として利用できる。
【００４４】
図２は、本発明に係るリン吸着材を用いたリン回収槽を、河川又は湖沼等の自然水系の浄化施設に適用した場合の概略図である。
【００４５】
当該施設において、沈殿池は、自然水系から導入した水を、汚泥と分離水に固液分離する。汚泥濃縮槽は、沈殿池から移送された汚泥を濃縮する。リン回収槽１には、被処理水として沈殿池及び汚泥濃縮槽から移送された分離水が供給される。分離水は、沈殿池及び汚泥濃縮槽における嫌気作用によって、リン酸に富んだものとなっている。分離水は、リン回収槽１内に導入されると、一定の滞留時間の下、本発明のリン吸着材と接触し、分離水中のリン酸は、当該吸着材によって吸着除去される。処理水は、河川等の自然水系に放流される。リン成分を吸着した吸着材は、リン回収槽１から回収された後、図６、図７または図８記載の加熱処理施設に供される。尚、本実施形態でも、汚泥濃縮槽で濃縮した汚泥は、本発明のリン吸着材の原料として利用できる。
【００４６】
図３は、本発明のリン吸着材を備えたリン回収槽の実施形態例を示す概略図である。
【００４７】
リン回収槽１は、被処理水が供給される槽１０内に、複数の吸着カートリッジ１１を備えている。吸着カートリッジ１１は、回収交換できるように着脱自在に設けられる。また、槽１０内には迂流板１２が適宜複数設けられ、被処理水と吸着カートリッジとの接触効率を高めている。
【００４８】
吸着カートリッジ１１は、リン吸着材１１０を格納部材１１１に収納してなる。
【００４９】
リン吸着材１１０は、リン酸吸着機能を有するアルカリ質成分と、炭素成分と、を含有する。当該吸着材は、多孔質化した微粉体状の炭化物であり、その表面及び孔面にはアルカリ物質成分が位している状態となっており、アルカリ質成分と炭素成分とを含む原料を間接加熱によって熱分解処理することで得られる。リン吸着材１１０の生成方法は、後で説明する。
【００５０】
リン吸着材１１０の原料は、前述のように、アルカリ質成分と炭素成分を含んだものであればよい。例えば、下水汚泥、ＲＤＦ、ゴム廃材（廃棄タイヤ等）、合成樹脂組成物等が挙げられる。特に、ハロゲン物質などの有害物質を含まないものが望ましい。尚、有害物質含む場合には、後述の有害物質除去剤を併用するとよい。
【００５１】
リン酸を吸着するアルカリ物質成分としては、アルカリ金属またはアルカリ土類金属等がある。アルカリ金属としては、リチウム、ナトリウム、カリウム、ルビジウム、セシウム、フランシウム等がある。アルカリ土類金属としては、マグネシウム、カルシウム、ストロンチウム、バリウム、ラジウム等がある。また、リン酸を吸着するその他の金属成分としては、アルミニウムや鉄等がある。特に、アルミニウム、カルシウム及びマグシウムは、好ましい成分である。
【００５２】
格納部材１１１は、透水性であって且つ粉末状のリン吸着材１１０を格納できる形状であればよく、例えば袋状や箱状に形成される。
【００５３】
格納部材１１１の素材としては、透水性で加熱分解処理しやすいものが採用される。当該素材には、例えば、天然繊維及び合成繊維等がある。合成繊維としては、例えば、ポリアミド、ポリエチレンテレフタレート、ポリエチレン、ポリプロピレン、ポリスチレンを含んでなるものがある。
【００５４】
また、格納部材１１１表面には、リンを吸着する材料を適宜坦持させてもよい。かかる構成とすることで、リン成分の回収効率がより一層向上する。リンを吸着する材料としては、前記アルカリ物質成分がある。さらに、格納部材１１１表面は、親水性を発現するように、適宜変性処理される。変性法としては、既知の方法でよく、例えば、グロー放電法やグラフト処理法等がある。
【００５５】
また、原料がハロゲン物質などの有害物質を含む場合には、有害物質を除去できるアルカリ物質等の有害物質除去剤を添加して加熱処理することで、原料に含まれる塩素成分や硫黄成分は無害な物質（無機塩等）に置換されるので、リン吸着材１１０の生成過程では、塩化水素等のハロゲン化水素の発生、ダイオキシン類の生成といった有害物質発生の問題は起こらない。しかも、炭化物内にダイオキシン類が吸着されることもない。
【００５６】
有害物質除去剤としては、例えば、アルカリ金属化合物、アルカリ土類金属化合物中の少なくとも１種類を選択または２種類以上を含有するものが有効である。
【００５７】
アルカリ金属化合物には、リチウム、ナトリウム、カリウム、ルビジウム、セシウムまたはフランシウムの、酸化物、水酸化物、炭酸水素塩、炭酸塩、ケイ酸塩、アルミン酸塩、硝酸塩または硫酸塩等が挙げられる。具体的に、例えば、炭酸水素ナトリウム、炭酸ナトリウム、セスキ炭酸ナトリウム、天然ソーダ、炭酸カリウム、炭酸水素カリウム、炭酸ナトリウムカリウム、水酸化ナトリウム、水酸化カリウム等が挙げられる。尚、炭酸水素ナトリウムは、酸性炭酸ナトリウム、重炭酸ナトリウムまたは重炭酸ソーダと別称される。炭酸ナトリウムは、炭酸ソーダ、ソーダ、ソーダ灰、洗濯ソーダまたは結晶ソーダと別称される。セスキ炭酸ナトリウムは、二炭酸一水素ナトリウム、三二炭酸水素ナトリウムまたはナトリウムセスキカーボネートと別称される。天然ソーダは、トロナと別称される。
【００５８】
アルカリ土類金属化合物には、カルシウム、ストロンチウム、バリウムまたはラジウム等の、酸化物、水酸化物、炭酸水素塩または炭酸塩等が挙げられる。具体的に、例えば、石灰（ＣａＯ）、消石灰（Ｃａ（ＯＨ）_２）、炭酸カルシウム（ＣａＣＯ_３）またはドロマイド（ＣａＣＯ_３・ＭｇＣＯ_３）等が挙げられる。
【００５９】
（実施形態２）本発明のリン吸着材の生成
図４は、本発明のリン吸着材を生成する施設の概略図である。
【００６０】
乾燥炉２は、原料を乾燥処理するための手段である。原料としては、先に例示したような下水汚泥、ゴム廃材等がある。このとき、原料は、計量されながら定量的に供給される。
【００６１】
乾燥炉２は、回転キルン方式を採用し、回転自在の回転炉２１と、回転炉２１の外周にガスダクトを形成し、熱風ガスを導入して回転炉２１を外部から加熱する外部加熱手段としての加熱ジャケット２２と、回転炉２１を両端側で回転自在に支承する支持ローラと、回転炉２１を回転駆動する回転駆動源と、を具備する。尚、熱風ガスは、後述の熱風炉２４から導入している。
【００６２】
回転炉２１は、その一端側に原料を搬入する供給口を、また他端側に排出口を設け、円筒体内部には搬送物を攪拌搬送するための送り羽根が複数枚具備する。そして、供給ダクト２０から供給された原料を、供給口側から回転炉２１に導入し、回転炉２１の回転によって、該原料を撹拌しながらの排出口側への移送を可能とさせている。また、供給ダクト２０には、原料さらには必要に応じて、（Ａ）ラインを介して、前記有害物質除去剤を投入するホッパー設備２０１が設けられる。尚、有害物質除去剤は、原料を乾燥処理した後に、連絡ダクト３０において、添加してもよい（（Ｂ）ライン）。
【００６３】
熱分解炉４は、乾燥炉２にて乾燥処理した原料を熱分解処理し、多孔質性の炭化物を得るための手段で、回転キルン方式を採用し、乾燥炉２と同様の構成をなし、回転炉４１と加熱ジャケット４２とを備える。
【００６４】
乾燥炉２と熱分解炉４は、図示されたように、熱分解炉４の供給口が乾燥炉２の排出口と連絡するように配置される。このとき、乾燥炉２の排出口と熱分解炉４の供給口には、これら排出口と供給口を覆って連通する連絡ダクト３０が設けられる。連絡ダクト３０には、乾燥炉２で乾燥処理した原料を解砕する解砕手段３と、解砕処理した原料を熱分解炉４に搬送するための搬送手段３１が具備される。
【００６５】
図５は、解砕手段と搬送手段とを設けた連絡ダクトの概略構成図である。ここでは、乾燥炉２から移送された玉化した原料の解砕処理を行うと共に、加熱処理によって発生した水蒸気と熱分解ガスの混合を防ぐことで、加熱処理施設における腐食現象や閉塞現象を回避させ、安定した加熱処理を図る。
【００６６】
解砕手段３は、可撓性継ぎ手３０６によって連絡ダクト３０に接続される。このとき、解砕手段３における原料供給側には、誘導板３０５が適宜設けられる。解砕手段３は、原料が導入される胴体３０３に、一対の回転体３０４を具備する。そして、互いに回転方向の異なる回転体３０４の間に原料を挿入させて圧搾することにより、玉化した原料を粉砕する。
【００６７】
搬送手段３１は、解砕された原料を受け入れるホッパー部３１０を備えている。このとき、ホッパー部３１０は、乾燥炉２から排出された水蒸気を主成分とする気相と、熱分解炉４から排出された熱分解ガスを主成分とする気相と、が混ざらないように、設けられる。水蒸気を主成分とする気相及び熱分解ガスを主成分とする気相は、連絡ダクト３０に接続された経路３０１，３０２を介してガス燃焼炉６に移送して燃焼処理する。尚、搬送手段３１は、原料供給量を調節できるように、回転速度可変な駆動源Ｍを具備している。
【００６８】
図４において、熱風炉２４は、熱風ガスを供給するための手段で、熱風ガスを発生させるための燃焼バーナー２４０を備えている。発生した熱風ガスは、先ず、熱分解炉４の加熱ジャケット４２に供され、回転炉４１を加熱した後に、乾燥炉２の加熱ジャケット２２内に供給され、回転炉２１を加熱する。加熱ジャケット２２から排出された熱風ガスは排気するが、一部のガスはガス燃焼炉６におけるエゼクタ駆動ガスとして利用している。
【００６９】
また、熱風ガスは、温度調整用の空気が注入され、ガス温度が適宜調整される。例えば、乾燥炉２においては、回転炉２１を３５０〜４５０℃で加熱するように調節される。尚、熱分解炉４においては、回転炉４１を４５０〜７００℃で加熱している。このようにして、乾燥炉１内に導入された原料は、間接加熱によって乾燥処理される。また、熱分解炉４内に導入された原料は、間接加熱によって熱分解処理される。熱分解炉４で得られた炭化物は、有機成分等が除去されて多孔質となっていると共に、その表面はアルカリ金属やアルカリ土類金属が露出した状態で形成されている。そして、この炭化物がリン吸着材となる。
【００７０】
粉砕移送手段５は、熱分解炉４で得た炭化物を粉砕し回収するための手段である。粉砕移送手段５は、搬送物（炭化物）を搬送する胴体５０内に、回転速度可変な駆動源Ｍを備えたスクリューを具備している。胴体５０は水冷ジャケット５１を付帯し、炭化物は冷却処理されながら粉砕移送される。
【００７１】
ガス燃焼炉６は、乾燥炉２で発生した水蒸気及び熱分解炉４で発生した熱分解ガスを、一定の雰囲気及び滞留時間のもとで（例えば、約８５０℃の雰囲気で、２秒以上の滞留時間）燃焼し、無害化処理する。水蒸気及び熱分解ガスは、経路３０１，３０２を介してエゼクタブロアによって導入される。このとき、いずれの被処理ガスにも、系外から空気が適宜導入される。
【００７２】
ガス燃焼炉６は、導入したガスを燃焼するガス燃焼室を備える。ガス燃焼室においては、水蒸気及び熱分解ガスを、それぞれエゼクタ６１ａ，６１ｂを介して導入し、燃焼バーナー６０によって混合燃焼する。このとき、熱分解ガスが充分発生している場合には、燃焼バーナー６０による燃焼は、燃料の供給を絞ることにより適宜制限される。また、ガス燃焼炉６にて燃焼処理したガスは、空気を冷却媒体とする気体−気体熱交換方式の熱交換器６２によって冷却処理し、さらにバグフィルタ６３に供した後、ブロア６４によって煙突６５から大気に開放している。尚、熱交換器６２にて、加熱された空気は、熱風炉２４での熱風ガスの生成に供される。
【００７３】
（実施形態３）リン吸着材の回収
図６は、実施形態１において使用済みのリン吸着材を回収したときのリン吸着材乾燥処理施設の概略図である。尚、図４記載の手段と同様な構成の手段には、当該手段と同一の符号を付して説明する。
【００７４】
乾燥炉２は、リン回収槽１から回収した吸着カートリッジ１１（リン吸着材１１０，格納部材１１１）を乾燥処理する手段で、回転キルン方式を採用し、図４記載の乾燥炉２と同様の構成をなす。尚、本実施形態の乾燥炉２におけるホッパー設備２０１は、ホッパー部２０１にて、互いに回転方向の異なる回転体２０２によって吸着カートリッジ１１を圧搾することにより、リン吸着材１１０と格納部材１１１の断片とに破砕処理している。
【００７５】
破砕処理された吸着カートリッジ１１は、乾燥炉２に供されるが、このとき、加熱ジャケット２２には３５０〜４５０℃程度の熱風ガスが熱風炉２４から供給され、回転炉２１内の温度は１００〜１５０℃程度となる。
【００７６】
このとき、回転炉２１内にて発生した水蒸気は、脱臭などの目的に応じて、排出ダクト２３に接続された経路２３１を介して、ガス燃焼炉６に供され、燃焼処理される。燃焼処理されたガスは、熱交換器６２及びバグフィルタ６２に供された後に、ブロア６４によって煙突６５から大気開放される。
【００７７】
一方、乾燥処理されたリン吸着材１１０と格納部材１１１の断片は、排出ダクト２３に接続された経路２３２を介して、回収され、その後、分別処理される。回収されたリン吸着材１１０は、リン成分が豊富なので、土壌改良剤や肥料等の原料として利用できる。
【００７８】
（実施形態４）回収したリン吸着材の処理
図７は、実施形態１において使用済みのリン吸着材を回収したときの、リン吸着材処理施設の概略図である。尚、図４及び図６記載の手段と同一の手段には、当該手段と同一の符号を付して、その説明を省略した。
【００７９】
ここでは、リン回収槽１から回収した吸着カートリッジ１１（吸着材１１０，格納部材１１１）を乾燥処理し、その後、さらに間接加熱することで、被処理物（乾燥処理したリン吸着材１１０及び格納部材１１１）に含まれる有機物成分及び水分を熱分解除去している。すなわち、図６における乾燥工程のみでは、吸着材の細孔内に有機物及び水分が存在する可能性があるので、これらを一層除去して吸着材の多孔質再生化（比表面積の拡大）を図り、より有効な肥料等として利用できるものに加工する。
【００８０】
加熱加工炉７は、乾燥炉２から搬送された被処理物を間接加熱によって、被処理物中の有機物成分及び水分を熱分解除去するため手段で、乾燥炉２と同様の構成となす。すなわち、回転キルン方式を採用し、回転炉７１と加熱ジャケット７２とを備える。回転炉７１において、被処理物の供給側には、乾燥炉２と連絡する連絡ダクト３０が接続され、処理物の排出側には、排出ダクト７３が接続されている。尚、連絡ダクト３０内部には、被処理物を加熱加工炉７に誘導させるための誘導板３０７が設置されている。
【００８１】
加熱ジャケット７２には、熱風炉２４から４５０〜７００℃程度の熱風ガスが、経路７２１を介し導入され、回転炉７１内は４００〜６００℃程度にとなる。また、乾燥炉２の加熱ジャケット２２には、加熱ジャケット７２から排出された熱風ガスが経路２２１を介して導入され、回転炉２１内は３５０〜４５０℃で加熱される。
【００８２】
このとき、回転炉７１内のリン吸着材１１０及び格納部材１１１の断片に含まれる有機物成分及び水分が熱分解除去され、炭化物が得られる。回転炉７１内で得られた炭化物は排出ダクト７３から回収される。当該炭化物は、リン成分を豊富に含むと共に細孔が再生されているので、保水性及び微生物の繁殖性に優れた土壌改良材及び肥料として利用できる。
【００８３】
（実施形態５）回収したリン吸着材の処理
図８は、実施形態１において使用済みのリン吸着材を回収したときの、リン吸着材加熱加工処理施設の他の実施形態を示した概略図である。尚、図４、図６及び図７記載の手段と同一の手段には、当該手段と同一の符号を付してその説明を省略した。
【００８４】
ここでは、リン回収槽１から回収した吸着カートリッジ１１（吸着材１１０，格納部材１１１）を乾燥処理し、その後、燃焼処理することで、被処理物（乾燥処理したリン吸着材１１０及び格納部材１１１）に含まれる炭素成分を除去し、リン及びリン化合物を回収している。
【００８５】
処理物加工燃焼炉８は、乾燥炉２で乾燥処理した吸着材１１０及び格納部材１１１を燃焼処理して炭素成分を除去するため手段である。被処理物は、排出ダクト３０から経路８０１を介して導入している。
【００８６】
処理物加工燃焼炉８は、図示省略した回転炉から構成され、回転炉は、筒状の鋼材からなり、その筒状の鋼材の内部にはキャスタブル材による耐火・耐熱層（図示省略）が設けられている。その回転炉は、軸方向の両側が図示省略した回転ローラで支持され、中央部には、駆動源により回転される手段を備えている。回転炉は、進行方向に適度に傾斜して構成され、自然搬送が可能となるようにしている。また、回転炉の上流側、すなわち、被処理物投入側には、図示省略された箱状の投入ジャケットがシールを介して具備され、さらに被処理物の搬送手段（スクリュー、スパイラル）と、被処理物を着火燃焼する燃焼バーナー８０とが具備される。一方、回転炉の下流側、すなわち、灰化物排出側には、内部にキャスタブル材による耐火・耐熱層（図示省略）を装着した箱状の排出ジャケットが備えられている。
【００８７】
処理物加工燃焼炉８における加熱加工温度は、６００〜７００℃程度で行う。排出ジャケットから排出された残渣は、リン及びリン化合物を主成分とし、経路８０２を介して回収される。リン及びリン含有物は、各種の原料として再利用できる。
【００８８】
一方、処理物加工燃焼炉８から排出された燃焼排ガスは、経路８０３を介してガス燃焼炉６に供給され燃焼処理される。このとき、ガス燃焼炉６には、乾燥炉２から水蒸気が、経路３０１を介して導入される。ガス燃焼炉６にて燃焼処理されたガスは、熱交換器６１及びバグフィルタ６２を経て系外移送される。
【００８９】
【発明の効果】
以上の説明から明らかなように、本発明は以下の効果を奏する。
【００９０】
本発明のリン吸着材は、炭素を骨格とした多孔質体であり、その表面及び孔内壁はアルカリ物質を露出させているので、水中のリンと接触効率が向上し、効率的なリンの回収が行える。各種汚水中からリンを効率的に回収できることから、自然水系における富栄養化の問題解決に寄与する。また、下水処理場などの汚水系に適用した場合には、リンが汚泥中に埋没しないことから、発生汚泥の削減化が図れる。
【００９１】
さらに、本発明のリン吸着材は、原料がハロゲン物質などの有害物質を含有する場合には該有害物質を除去する有害物質除去剤を添加混合することで、ハロゲン化合物（例えば、ダイオキシン類等）を含むことのないリン吸着材を得ることができる。つまり、原料に塩素成分等のハロゲン成分が含まれていても、有害物質除去剤によって無害な物質（無機塩）に置換される。したがって、本発明のリン吸着材の生成過程では、塩化水素の発生、機器の腐蝕、ダイオキシン類の生成の問題は起こらない。
【００９２】
また、本発明のリン吸着材で回収したリンは、乾燥すること、加熱加工すること、骨格の炭素分を燃焼除去すること等、目的に応じた加工を行うことにより、土壌改良材、肥料として直接利用可能であり、また炭素分の焼却除去することで、リン成分を回収できることから各種目的の原材料としての有効利用が可能となる。
【図面の簡単な説明】
【図１】本発明に係るリン吸着材の第一の実施形態を示した概略図。
【図２】本発明に係るリン吸着材の第二の実施形態を示した概略図。
【図３】リン回収槽の実施形態を示した概略図。
【図４】本発明のリン吸着材を生成する施設を示した概略図。
【図５】解砕手段と搬送手段とを設けた連絡ダクトの概略構成図。
【図６】使用済みのリン吸着材を回収したときのリン吸着材乾燥処理施設の概略図。
【図７】使用済みのリン吸着材を回収したときの、リン吸着材処理施設の概略図。
【図８】使用済みのリン吸着材を回収したときの、リン吸着材加熱処理施設の他の実施形態を示した概略図。
【図９】試料１のリン吸着性能を示した特性図。
【図１０】試料２のリン吸着性能を示した特性図。
【図１１】試料３のリン吸着性能を示した特性図。
【図１２】試料４のリン吸着性能を示した特性図。
【図１３】試料５のリン吸着性能を示した特性図。
【図１４】活性汚泥法に基づく下水処理システムの概略図。
【符号の説明】
１…リン回収槽、１１…吸着カートリッジ、１１０…リン吸着材、１１１…格納部材、１２…迂流板
２…乾燥炉
３…解砕手段
４…熱分解炉
５…粉砕移送手段
６…ガス燃焼炉
７…加熱加工炉
８…処理物加工燃焼炉[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention recovers phosphorus components and the like contained in wastewater, natural water systems (rivers, lakes, dam reservoirs, etc.) and the like to prevent eutrophication of rivers and lakes, and further processes the recovered phosphorus. It is related to technology for reuse.
[0002]
[Prior art]
The activated sludge method is generally employed for sewage treatment.
[0003]
FIG. 14 is a schematic diagram of a sewage treatment system based on the activated sludge method.
[0004]
First, in the first sedimentation basin, the introduced sewage is solid-liquid separated into separated water and sludge. In the biological reaction tank, the separated water is biologically treated with activated sludge to decompose organic components in the separated water. Next, in the anaerobic fermenter, the biological reaction treated water is subjected to anaerobic fermentation treatment. Then, in the final sedimentation basin, the anaerobic fermentation treatment water is subjected to solid-liquid separation. The treated water obtained by solid-liquid separation is discharged into rivers. In the sludge thickening tank, the sludge (containing the phosphorus component) separated in the first settling tank and the last settling tank is further solid-liquid separated and concentrated. At this time, the concentrated sludge has been landfilled, incinerated or carbonized. On the other hand, the separated water obtained by the solid-liquid separation is appropriately returned to the biological reaction tank for reprocessing.
[0005]
According to the activated sludge method, sewage is treated by microorganisms contained in activated sludge, and treated water contains nitrogen components (ammonium nitrogen, nitrite nitrogen, nitrate nitrogen) and phosphorus components (phosphoric acid). Become. Treated water containing nitrogen and phosphorus components is strictly regulated today because it causes eutrophication of water quality when discharged into rivers. Therefore, in the biological reaction tank, nitrogen components are further removed by biological denitrification treatment. Further, in the anaerobic fermenter, the phosphorus component eluted in the form of phosphoric acid from the cells of the sludge microorganisms is precipitated and separated by the addition of a coagulant (for example, JP-A-2001-149981).
[0006]
However, this method does not effectively utilize the phosphorus component.
[0007]
Therefore, a technique for recovering and recycling a phosphorus component from various liquid phases has been proposed.
[0008]
For example, focusing on calcium, recovering phosphorus by binding of phosphate ions and calcium ions (for example, JP-A-2000-233189), focusing on the pH of water to be treated, and adjusting the properties of the adsorbent For adjusting the pH value of the water to be treated to an alkaline side (for example, Japanese Patent Application Laid-Open No. 2001-219178), and further, focusing on activated carbon and carbide, the porous properties of activated carbon, or the presence of calcium component in carbide (For example, JP-A-2001-219178 and JP-A-55-104908) are known.
[0009]
[Problems to be solved by the invention]
In the above-mentioned conventional method, for example, Japanese Patent Application Laid-Open No. 2001-219178 discloses that sludge or the like that has been treated as waste is processed into a porous carbonized material to form a large specific surface area, and a phosphorus trapping effect. It is a technology that seeks to obtain.
[0010]
However, since this method obtains carbides from sewage sludge (lime-based, polymer-based) or municipal solid waste RDF (solidified waste fuel), these treated materials often contain a chlorine component. . In particular, in the case of polymer sludge using a cationic polymer flocculant, chlorine components are contained, so if these are simply carbonized, hydrogen chloride will be generated, equipment will corrode, and dioxins will be generated. Further, there is a possibility that dioxins are adsorbed in the carbide. Therefore, it is necessary to remove components that can be harmful, such as halogen components and sulfur components.
[0011]
The present invention has been made in view of the above circumstances, and an object of the present invention is to efficiently remove and effectively use a phosphorus component contained in water to be treated, and to effectively use general waste and industrial waste safely. Another object of the present invention is to provide a phosphorus adsorbent, a method for producing the same, a method for recovering phosphorus, a method for treating a phosphorus adsorbent, and a method for treating water containing a phosphorus component.
[0012]
[Means for Solving the Problems]
The present invention has been made by focusing on an alkaline substance component contained in general waste and industrial waste, particularly an alkaline substance component that adsorbs a phosphorus component.
[0013]
That is, the present invention for solving the above problems has the following features.
[0014]
The invention according to claim 1 is a phosphorus adsorbent containing an alkaline substance component and a carbon component, wherein the skeleton component of the adsorbent is made of a porous carbide, and the alkaline component is present on the surface and the pore surface. It is characterized in that
[0015]
The invention according to claim 2 is a method for producing a phosphorus adsorbent comprising an alkaline substance component and a carbon component,
It is characterized in that a porous adsorbent containing an alkaline component and a carbon component is obtained by thermally decomposing a raw material containing an alkaline component and a carbon component without containing a harmful substance component by indirect heating.
[0016]
The invention according to claim 3 is a method for producing a phosphorus adsorbent comprising an alkaline substance component and a carbon component,
By adding and mixing a harmful substance remover to a raw material containing an alkaline substance component and a carbon component and performing a thermal decomposition treatment by indirect heating, a porous adsorbent containing an alkali component and a carbon component without a harmful substance component can be obtained. Gain
It is characterized by.
[0017]
The invention according to claim 4 is a method for recovering a phosphorus component in water to be treated,
The water to be treated is brought into contact with a phosphorus adsorbent containing an alkaline component and a carbon component and having an alkaline component on its surface and pore surface to adsorb and remove the phosphorus component contained in the water to be treated. It is characterized by doing.
[0018]
According to a fifth aspect of the present invention, in the method for recovering phosphorus according to the fourth aspect, the phosphorus adsorbent is an adsorption cartridge housed in a water-permeable storage member, and the adsorption cartridge is immersed in the treated water. Features.
[0019]
According to a sixth aspect of the present invention, in the method for recovering phosphorus according to the fourth or fifth aspect,
A plurality of adsorption cartridges are removably arranged to form a phosphorus recovery tank, and the phosphorus recovery tank is provided in a supply line of the water to be treated.
[0020]
According to a seventh aspect of the present invention, in the method for recovering phosphorus according to the sixth aspect, the water to be treated containing a phosphorus component is wastewater or natural water derived from the activated sludge method, and the separation obtained from the water to be treated is used. It is characterized in that water is introduced into a phosphorus decomposition tank.
[0021]
According to an eighth aspect of the present invention, in the method for recovering phosphorus according to any one of the fourth to seventh aspects, the adsorbent which is immersed in the water to be treated and adsorbed and trapped the phosphorus component in the water to be treated is dried. It is characterized by recovering after removing water.
[0022]
The invention according to claim 9 is a method for treating a phosphorus adsorbent that has adsorbed a phosphorus component, wherein the step of drying the phosphorus adsorbent that has adsorbed the phosphorus component and removing moisture is performed;
Removing the organic components and moisture contained in the dried phosphorus adsorbent by indirect heating of the adsorbent.
[0023]
The invention according to claim 10 is a method for treating an adsorbent that has adsorbed a phosphorus component,
A step of drying the phosphorus adsorbent that has absorbed the phosphorus component to remove moisture,
Burning the dried phosphorus adsorbent to remove carbon components forming the adsorbent.
[0024]
The invention according to claim 11 is a water treatment method for removing a phosphorus component,
Subjecting the sewage to an anaerobic fermenter to ferment,
A step of subjecting the wastewater subjected to the anaerobic fermentation treatment to a sedimentation basin to perform solid-liquid separation of separated water containing a phosphorus component,
A step of supplying the separated water to a phosphorus recovery tank containing a phosphorus adsorbent containing an alkaline component and a carbon component and having the alkaline component on the surface thereof to adsorb and remove the phosphorus component contained in the separated water. And having the following.
[0025]
The invention according to claim 12 is a water treatment method for removing a phosphorus component,
A step of subjecting the water to be treated to a sedimentation basin to perform solid-liquid separation of separated water containing a phosphorus component,
A step of supplying the separated water to a phosphorus recovery tank containing a phosphorus adsorbent containing an alkaline component and a carbon component and having the alkaline component on the surface thereof to adsorb and remove the phosphorus component contained in the separated water. And having the following.
[0026]
A thirteenth aspect of the present invention is the water treatment method according to the twelfth aspect, wherein the water to be treated is introduced from a natural water system.
[0027]
According to a fourteenth aspect of the present invention, in the water treatment method according to any one of the eleventh to thirteenth aspects, the phosphorus recovery tank is provided with a plurality of detachable adsorption cartridges in a tank to which the water to be treated is supplied, The adsorption cartridge is characterized in that the adsorbent is stored in a water-permeable storage member.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
The inventor tested the phosphorus adsorption performance of a carbide obtained from a rubber component when creating the present invention. Here, a predetermined amount of powdered carbide (samples 1 to 5) generated from various raw materials was added to 500 ml of a phosphoric acid solution having a predetermined concentration of 20 mg / l measured in a beaker, and stirred with a magnetic stirrer. Phosphoric acid residual concentration (mg / l) was examined over time. The measurement of the phosphoric acid concentration was based on the spectrophotometric method. Table 1 shows the sample raw materials and their chemical components (mass spectrometry results by the EPMA method).
[0029]
[Table 1]

[0030]
In Table 1, Sample 1 was obtained by heating a rubber containing BR (polybutadiene rubber), CSM (chlorosulfonated polyethylene rubber), CR (chloroprene rubber), and CB (carbon black) as a raw material. It is a carbide.
[0031]
Sample 2 is a carbide obtained by using a rubber containing BR, EPDM (ethylene propylene rubber) and CB as a raw material and subjecting the rubber to heat treatment.
[0032]
Sample 3 is a carbide obtained by using a rubber containing BR, EPDM, and CB as a raw material and subjecting the rubber to heat treatment.
[0033]
Sample 4 is a carbide obtained by heating a rubber containing BR and CB as a raw material.
[0034]
Sample 5 is a carbide obtained by heating a rubber containing BR as a raw material.
[0035]
FIG. 9 is a characteristic diagram showing the adsorption performance of the phosphorus component of Sample 1. Here, the change over time of the residual concentration of phosphoric acid when 0.2 g, 0.5 g, and 1 g of Sample 1 are added to 500 ml of the phosphoric acid solution is shown. According to these results, the removal performance of the phosphorus component depends on the amount of the sample 1 added. In particular, when 1 g or more is added to 500 ml of a 20 mg / l phosphoric acid solution, the removal rate of phosphoric acid is almost 100%. % Can be confirmed.
[0036]
FIG. 10 is a characteristic diagram showing the adsorption performance of the phosphorus component of Sample 2. Here, the change with time of the phosphoric acid residual concentration when 0.1 g, 0.2 g, 0.5 g, and 1 g of Sample 2 are added to 500 ml of the phosphoric acid solution is shown. According to these results, like the sample 1, the removal performance of the phosphorus component depends on the amount of the sample 2 added. In particular, if 1 g or more is added to 500 ml of a 20 mg / l phosphoric acid solution, the phosphorus content can be reduced in a short time. It can be confirmed that the acid removal rate is almost 100%.
[0037]
FIG. 11 is a characteristic diagram showing the adsorption performance of the phosphorus component of Sample 3. Here, the change over time of the residual concentration of phosphoric acid when 5 g of sample 3 is added to 500 ml of the phosphoric acid solution is shown. According to these results, it can be confirmed that a good phosphorus adsorption performance (removal rate of about 100%) was obtained within a contact time of about 10 minutes between the solution and the sample.
[0038]
FIG. 12 is a characteristic diagram showing the adsorption performance of the phosphorus component of Sample 4. Here, the change over time in the residual concentration of phosphoric acid when 5 g of sample 4 is added to 500 ml of the phosphoric acid solution is shown. According to these results, the phosphoric acid removal rate remains at about 20%. As is clear from the component analysis results in Table 1, although the content of Sample 4 contained the Ca component, the content was smaller than that of Samples 1 to 3, and the adsorption effect of the phosphorus component was inferior to that of Samples 1 to 3. It became something.
[0039]
FIG. 13 is a characteristic diagram showing the adsorption performance of the phosphorus component of Sample 5. Here, the change over time of the residual concentration of phosphoric acid when 5 g of sample 5 is added to 500 ml of the phosphoric acid solution is shown. According to this result, the phosphoric acid removal rate of Sample 5 is less than 10%. As is clear from the component analysis results in Table 1, since Sample 5 did not contain a Ca component, the phosphorus component adsorption effect was inferior to Samples 1 to 3.
[0040]
An embodiment of the present invention created based on the above experimental results will be described.
[0041]
(Embodiment 1)
FIG. 1 is a schematic diagram of a system configuration using a phosphorus adsorbent according to the present invention, which is applied to a sewage treatment facility.
[0042]
Here, a phosphorus recovery tank 1 provided with the adsorbent of the present invention shown in FIG. 3 is installed in a sewage treatment facility based on the activated sludge method.
[0043]
In the figure, in the first settling basin, the introduced sewage is subjected to solid-liquid separation treatment. In the biological reaction tank, the solid-liquid separation water obtained in the first settling tank is brought into contact with activated sludge to biologically decompose and remove organic substances and nitrogen components in the liquid phase. In the anaerobic fermenter, the phosphorus component is eluted in the form of phosphoric acid from the cells of the activated sludge microorganism group by anaerobic fermentation of the biological reaction treated water. The final sedimentation basin performs a solid-liquid separation process on the anaerobic fermentation treatment water. The sludge thickening tank concentrates the sludge separated in the first settling tank and the final settling tank. Separated water obtained in the final sedimentation tank and the sludge concentration tank is transferred to the phosphorus recovery tank 1. The separated water is rich in phosphoric acid due to the anaerobic action in the anaerobic fermenter, the final sedimentation tank and the sludge thickener. When the separated water is introduced into the phosphorus recovery tank 1, it comes into contact with the phosphorus adsorbent of the present invention under a certain residence time. At this time, the phosphoric acid in the separated water is adsorbed and removed by the adsorbent. Treated water is discharged into natural water systems such as rivers. After the adsorbent that has adsorbed the phosphorus component is recovered from the phosphorus recovery tank 1, it is supplied to the heat treatment facility shown in FIG. 6, FIG. 7, or FIG. The sludge concentrated in the sludge concentration tank can be used as a raw material for the phosphorus adsorbent of the present invention.
[0044]
FIG. 2 is a schematic diagram of a case where the phosphorus recovery tank using the phosphorus adsorbent according to the present invention is applied to a natural water purification facility such as a river or a lake.
[0045]
In the facility, the sedimentation basin separates the water introduced from the natural water system into sludge and separated water. The sludge thickening tank concentrates the sludge transferred from the sedimentation basin. Separated water transferred from the sedimentation pond and the sludge concentration tank is supplied to the phosphorus recovery tank 1 as the water to be treated. The separated water is rich in phosphoric acid due to the anaerobic action in the sedimentation basin and the sludge thickening tank. When the separated water is introduced into the phosphorus recovery tank 1, it contacts the phosphorus adsorbent of the present invention for a certain residence time, and the phosphoric acid in the separated water is adsorbed and removed by the adsorbent. Treated water is discharged into natural water systems such as rivers. After the adsorbent that has adsorbed the phosphorus component is recovered from the phosphorus recovery tank 1, it is supplied to the heat treatment facility shown in FIG. 6, FIG. 7, or FIG. In addition, also in this embodiment, the sludge concentrated in the sludge concentration tank can be used as a raw material of the phosphorus adsorbent of the present invention.
[0046]
FIG. 3 is a schematic view showing an embodiment of a phosphorus recovery tank provided with the phosphorus adsorbent of the present invention.
[0047]
The phosphorus recovery tank 1 includes a plurality of adsorption cartridges 11 in a tank 10 to which water to be treated is supplied. The suction cartridge 11 is provided detachably so that it can be collected and replaced. Further, a plurality of detour plates 12 are appropriately provided in the tank 10 to increase the contact efficiency between the water to be treated and the adsorption cartridge.
[0048]
The adsorption cartridge 11 contains a phosphorus adsorbent 110 in a storage member 111.
[0049]
The phosphorus adsorbent 110 contains an alkaline component having a phosphoric acid adsorption function and a carbon component. The adsorbent is a porous fine powdered carbide, and the surface and pore surface of the adsorbent are in a state in which an alkaline substance component is located. It is obtained by thermal decomposition treatment by heating. The method for producing the phosphorus adsorbent 110 will be described later.
[0050]
As described above, the raw material of the phosphorus adsorbent 110 may be one containing an alkaline component and a carbon component. For example, sewage sludge, RDF, waste rubber materials (waste tires and the like), synthetic resin compositions and the like can be mentioned. In particular, a material that does not contain harmful substances such as halogen substances is desirable. When a harmful substance is contained, a harmful substance remover described below may be used in combination.
[0051]
Examples of the alkali substance component that adsorbs phosphoric acid include alkali metals and alkaline earth metals. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium, and francium. Examples of the alkaline earth metal include magnesium, calcium, strontium, barium, and radium. Other metal components that adsorb phosphoric acid include aluminum and iron. In particular, aluminum, calcium and magnesium are preferred components.
[0052]
The storage member 111 may have any shape as long as it is water-permeable and can store the powdered phosphorus adsorbent material 110, for example, in a bag shape or a box shape.
[0053]
As the material of the storage member 111, a material that is water-permeable and easily subjected to thermal decomposition treatment is employed. Such materials include, for example, natural fibers and synthetic fibers. Examples of the synthetic fibers include polyamide, polyethylene terephthalate, polyethylene, polypropylene, and polystyrene.
[0054]
Further, a material that adsorbs phosphorus may be appropriately carried on the surface of the storage member 111. With this configuration, the recovery efficiency of the phosphorus component is further improved. Examples of the material that adsorbs phosphorus include the above-mentioned alkaline substance components. Further, the surface of the storage member 111 is appropriately modified so as to exhibit hydrophilicity. As the modification method, a known method may be used, and examples thereof include a glow discharge method and a grafting method.
[0055]
In addition, when the raw material contains harmful substances such as halogen substances, chlorine and sulfur components contained in the raw materials are made harmless by adding a harmful substance remover such as an alkali substance that can remove harmful substances and performing heat treatment. In the process of forming the phosphorus adsorbent 110, there is no problem of generating harmful substances such as generation of hydrogen halide such as hydrogen chloride and generation of dioxins. Moreover, no dioxins are adsorbed in the carbide.
[0056]
As the harmful substance remover, for example, an agent which selects at least one kind or contains two or more kinds among alkali metal compounds and alkaline earth metal compounds is effective.
[0057]
Examples of the alkali metal compound include oxides, hydroxides, bicarbonates, carbonates, silicates, aluminates, nitrates, sulfates, and the like of lithium, sodium, potassium, rubidium, cesium, and francium. Specific examples include sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, potassium carbonate, potassium bicarbonate, sodium potassium carbonate, sodium hydroxide, potassium hydroxide and the like. Note that sodium bicarbonate is referred to as acidic sodium carbonate, sodium bicarbonate, or sodium bicarbonate. Sodium carbonate is also referred to as sodium carbonate, soda, soda ash, laundry soda or crystalline soda. Sodium sesquicarbonate is also referred to as sodium monohydrogen dicarbonate, sodium bicarbonate or sodium sesquicarbonate. Natural soda is also called trona.
[0058]
Alkaline earth metal compounds include oxides, hydroxides, bicarbonates or carbonates such as calcium, strontium, barium or radium. Specifically, for example, lime (CaO), slaked lime (Ca (OH) ₂ ), Calcium carbonate (CaCO ₃ ) Or dolomide (CaCO ₃ ・ MgCO ₃ ) And the like.
[0059]
(Embodiment 2) Production of phosphorus adsorbent of the present invention
FIG. 4 is a schematic diagram of a facility for producing the phosphorus adsorbent of the present invention.
[0060]
The drying furnace 2 is a means for drying the raw material. Raw materials include sewage sludge and rubber waste as exemplified above. At this time, the raw material is supplied quantitatively while being measured.
[0061]
The drying furnace 2 employs a rotary kiln system, and has a rotatable rotary furnace 21 and a gas duct formed on the outer periphery of the rotary furnace 21, and serves as external heating means for introducing hot air gas to heat the rotary furnace 21 from the outside. A heating jacket 22, a supporting roller for rotatably supporting the rotary furnace 21 at both ends, and a rotary drive source for rotating the rotary furnace 21 are provided. The hot blast gas is introduced from a hot blast stove 24 described later.
[0062]
The rotary furnace 21 is provided at one end with a supply port for loading the raw material and at the other end with a discharge port, and has a plurality of feed blades inside the cylindrical body for stirring and transporting the conveyed material. The raw material supplied from the supply duct 20 is introduced into the rotary furnace 21 from the supply port side, and the rotation of the rotary furnace 21 enables the raw material to be transferred to the discharge port side while stirring. Further, the supply duct 20 is provided with a hopper facility 201 for charging the harmful substance removing agent via the raw material and, if necessary, the (A) line. The harmful substance removing agent may be added in the communication duct 30 after the raw material is dried (line (B)).
[0063]
The pyrolysis furnace 4 is a means for pyrolyzing the raw material dried in the drying furnace 2 to obtain a porous carbide, employs a rotary kiln system, and has the same configuration as the drying furnace 2, A rotary furnace 41 and a heating jacket 42 are provided.
[0064]
The drying furnace 2 and the pyrolysis furnace 4 are arranged such that the supply port of the pyrolysis furnace 4 communicates with the discharge port of the drying furnace 2 as illustrated. At this time, a communication duct 30 that covers and communicates with the discharge port of the drying furnace 2 and the supply port of the pyrolysis furnace 4 covering the discharge port and the supply port is provided. The communication duct 30 is provided with a crushing means 3 for crushing the raw material dried in the drying furnace 2 and a conveying means 31 for conveying the crushed raw material to the pyrolysis furnace 4.
[0065]
FIG. 5 is a schematic configuration diagram of a communication duct provided with crushing means and transport means. Here, the crushed raw material transferred from the drying furnace 2 is crushed, and the mixing of water vapor and pyrolysis gas generated by the heat treatment is prevented, thereby avoiding the corrosion phenomenon and the clogging phenomenon in the heat treatment facility. And a stable heat treatment is achieved.
[0066]
The crushing means 3 is connected to the communication duct 30 by a flexible joint 306. At this time, a guide plate 305 is appropriately provided on the raw material supply side of the crushing means 3. The crushing means 3 includes a pair of rotating bodies 304 on a body 303 into which the raw material is introduced. Then, the raw material is inserted between the rotating bodies 304 having different rotation directions from each other and pressed to crush the raw material that has been beaded.
[0067]
The transport means 31 includes a hopper 310 for receiving the crushed raw material. At this time, the hopper 310 prevents the gas phase mainly composed of steam discharged from the drying furnace 2 and the gas phase mainly composed of pyrolysis gas discharged from the pyrolysis furnace 4 from mixing. , Is provided. The gaseous phase mainly composed of steam and the gaseous phase mainly composed of pyrolysis gas are transferred to the gas combustion furnace 6 via paths 301 and 302 connected to the communication duct 30 for combustion treatment. Note that the transport means 31 includes a drive source M whose rotation speed is variable so that the supply amount of the raw material can be adjusted.
[0068]
In FIG. 4, the hot blast stove 24 is a means for supplying hot blast gas, and includes a combustion burner 240 for generating hot blast gas. The generated hot air gas is first supplied to the heating jacket 42 of the pyrolysis furnace 4, and after heating the rotary furnace 41, is supplied into the heating jacket 22 of the drying furnace 2 to heat the rotary furnace 21. The hot-air gas discharged from the heating jacket 22 is exhausted, but a part of the gas is used as an ejector driving gas in the gas combustion furnace 6.
[0069]
The hot-air gas is supplied with air for temperature adjustment, and the gas temperature is appropriately adjusted. For example, in the drying furnace 2, adjustment is performed so that the rotary furnace 21 is heated at 350 to 450 ° C. In the pyrolysis furnace 4, the rotary furnace 41 is heated at 450 to 700 ° C. Thus, the raw material introduced into the drying furnace 1 is dried by indirect heating. Further, the raw material introduced into the thermal decomposition furnace 4 is subjected to a thermal decomposition treatment by indirect heating. The carbide obtained in the pyrolysis furnace 4 is made porous by removing organic components and the like, and its surface is formed in a state where an alkali metal or an alkaline earth metal is exposed. And this carbide becomes a phosphorus adsorbent.
[0070]
The crushing transfer means 5 is a means for crushing and collecting the carbide obtained in the pyrolysis furnace 4. The pulverizing transfer means 5 includes a screw provided with a drive source M having a variable rotation speed in a body 50 that conveys a conveyed material (carbide). The body 50 is provided with a water cooling jacket 51, and the carbide is pulverized and transferred while being cooled.
[0071]
The gas combustion furnace 6 converts the steam generated in the drying furnace 2 and the pyrolysis gas generated in the pyrolysis furnace 4 under a constant atmosphere and a residence time (for example, in an atmosphere of about 850 ° C. for 2 seconds or more). (Residence time) Burn and detoxify. Steam and pyrolysis gases are introduced by ejector blowers via paths 301,302. At this time, air is appropriately introduced into any of the gases to be processed from outside the system.
[0072]
The gas combustion furnace 6 includes a gas combustion chamber for burning the introduced gas. In the gas combustion chamber, steam and pyrolysis gas are introduced through ejectors 61a and 61b, respectively, and mixed and burned by a combustion burner 60. At this time, if the pyrolysis gas is sufficiently generated, the combustion by the combustion burner 60 is appropriately restricted by restricting the fuel supply. The gas burned in the gas combustion furnace 6 is cooled by a gas-gas heat exchange type heat exchanger 62 using air as a cooling medium, further supplied to a bag filter 63, and then passed through a chimney 65 by a blower 64. Is open to the atmosphere. The air heated in the heat exchanger 62 is used for generating hot air gas in the hot air stove 24.
[0073]
(Embodiment 3) Recovery of phosphorus adsorbent
FIG. 6 is a schematic diagram of the phosphorus adsorbent drying treatment facility when the used phosphorus adsorbent is recovered in the first embodiment. The means having the same configuration as the means shown in FIG. 4 will be described with the same reference numerals as those means.
[0074]
The drying furnace 2 is a means for drying the adsorption cartridge 11 (the phosphorus adsorbent 110 and the storage member 111) recovered from the phosphorus recovery tank 1, employs a rotary kiln system, and has the same configuration as the drying furnace 2 shown in FIG. Make Note that the hopper equipment 201 in the drying furnace 2 of the present embodiment compresses the adsorption cartridge 11 with rotating bodies 202 having different rotation directions from each other in the hopper section 201, so that the fragments of the phosphorus adsorbent 110 and the storage member 111 are separated. Crushed.
[0075]
The crushed adsorption cartridge 11 is supplied to the drying furnace 2. At this time, hot air gas of about 350 to 450 ° C. is supplied to the heating jacket 22 from the hot air furnace 24, and the temperature in the rotary furnace 21 is 100 About 150 ° C.
[0076]
At this time, the steam generated in the rotary furnace 21 is supplied to the gas combustion furnace 6 via a path 231 connected to the discharge duct 23 for combustion processing according to a purpose such as deodorization. After the gas subjected to the combustion treatment is supplied to the heat exchanger 62 and the bag filter 62, the gas is released from the chimney 65 to the atmosphere by the blower 64.
[0077]
On the other hand, the pieces of the phosphorus adsorbent 110 and the storage member 111 that have been subjected to the drying process are collected via a path 232 connected to the discharge duct 23, and then subjected to a separation process. Since the recovered phosphorus adsorbent 110 is rich in phosphorus components, it can be used as a raw material such as a soil conditioner or a fertilizer.
[0078]
(Embodiment 4) Treatment of recovered phosphorus adsorbent
FIG. 7 is a schematic diagram of the phosphorus adsorbent treatment facility when the used phosphorus adsorbent is recovered in the first embodiment. The same units as those shown in FIGS. 4 and 6 are denoted by the same reference numerals, and the description thereof is omitted.
[0079]
Here, the adsorption cartridge 11 (the adsorbent 110 and the storage member 111) collected from the phosphorus recovery tank 1 is subjected to a drying process, and then further indirectly heated, thereby performing an object to be processed (the dried phosphorus adsorption material 110 and the storage member 111). 111) The organic components and moisture contained in 111) are thermally decomposed and removed. In other words, in the drying step in FIG. 6 alone, there is a possibility that organic matter and moisture may be present in the pores of the adsorbent, and these are further removed to regenerate the adsorbent into porous material (enlarge the specific surface area). , Which can be used as more effective fertilizers.
[0080]
The heating processing furnace 7 is a means for thermally decomposing and removing organic components and moisture in the object to be processed conveyed from the drying furnace 2 by indirect heating, and has the same configuration as the drying furnace 2. That is, a rotary kiln system is adopted, and a rotary furnace 71 and a heating jacket 72 are provided. In the rotary furnace 71, a communication duct 30 that communicates with the drying furnace 2 is connected to a supply side of the processing object, and a discharge duct 73 is connected to a discharge side of the processing object. Note that a guide plate 307 for guiding an object to be processed into the heating processing furnace 7 is provided inside the communication duct 30.
[0081]
Hot-air gas of about 450 to 700 ° C. is introduced into the heating jacket 72 from the hot-air furnace 24 via a path 721, and the inside of the rotary furnace 71 becomes about 400 to 600 ° C. Further, the hot air gas discharged from the heating jacket 72 is introduced into the heating jacket 22 of the drying furnace 2 via the path 221, and the inside of the rotary furnace 21 is heated at 350 to 450 ° C.
[0082]
At this time, organic components and moisture contained in the fragments of the phosphorus adsorbent 110 and the storage member 111 in the rotary furnace 71 are thermally decomposed and removed, and a carbide is obtained. The carbide obtained in the rotary furnace 71 is recovered from the discharge duct 73. Since the carbide contains a large amount of a phosphorus component and regenerated pores, it can be used as a soil conditioner and a fertilizer excellent in water retention and microorganism propagation.
[0083]
(Embodiment 5) Treatment of collected phosphorus adsorbent
FIG. 8 is a schematic diagram showing another embodiment of the phosphorus adsorbent heat processing facility when the used phosphorus adsorbent is recovered in the first embodiment. The same means as those shown in FIGS. 4, 6, and 7 are denoted by the same reference numerals, and description thereof is omitted.
[0084]
Here, the adsorption cartridge 11 (the adsorbent 110 and the storage member 111) collected from the phosphorus recovery tank 1 is subjected to a drying process, and then subjected to a combustion process, so that the object to be processed (the dried phosphorus adsorbent 110 and the storage member 111) is processed. ) Is removed to recover phosphorus and phosphorus compounds.
[0085]
The treated material processing combustion furnace 8 is a means for burning the adsorbent 110 and the storage member 111 that have been dried in the drying furnace 2 to remove carbon components. The object to be processed is introduced from the discharge duct 30 via the path 801.
[0086]
The processing object combustion furnace 8 is composed of a rotary furnace not shown, and the rotary furnace is made of a tubular steel material, and a refractory and heat resistant layer (not shown) of a castable material is provided inside the tubular steel material. Have been. The rotary furnace is supported by rotating rollers (not shown) on both sides in the axial direction, and is provided at a center portion with a means rotated by a driving source. The rotary furnace is configured to be appropriately inclined in the traveling direction so that natural transport is possible. In addition, a box-shaped charging jacket (not shown) is provided via a seal on the upstream side of the rotary furnace, that is, on the charging side of the workpiece. A combustion burner 80 for igniting and burning the processed material is provided. On the other hand, on the downstream side of the rotary furnace, that is, on the ash discharge side, there is provided a box-shaped discharge jacket having a refractory and heat-resistant layer (not shown) made of castable material inside.
[0087]
The heating temperature in the processing object combustion furnace 8 is about 600 to 700 ° C. The residue discharged from the discharge jacket contains phosphorus and a phosphorus compound as main components and is collected via a path 802. Phosphorus and phosphorus-containing substances can be reused as various raw materials.
[0088]
On the other hand, the combustion exhaust gas discharged from the processed material processing furnace 8 is supplied to the gas combustion furnace 6 via the path 803 and is subjected to combustion processing. At this time, steam is introduced into the gas combustion furnace 6 from the drying furnace 2 via the path 301. The gas subjected to the combustion treatment in the gas combustion furnace 6 is transferred outside the system via the heat exchanger 61 and the bag filter 62.
[0089]
【The invention's effect】
As is clear from the above description, the present invention has the following effects.
[0090]
The phosphorus adsorbent of the present invention is a porous body having a carbon skeleton, and its surface and inner walls of the pores expose an alkali substance, so that the efficiency of contact with phosphorus in water is improved, and efficient phosphorus recovery is achieved. Can be performed. Since phosphorus can be efficiently recovered from various types of wastewater, it contributes to solving the problem of eutrophication in natural water systems. In addition, when applied to a sewage system such as a sewage treatment plant, phosphorus is not buried in the sludge, so that the generated sludge can be reduced.
[0091]
Furthermore, when the raw material contains a harmful substance such as a halogen substance, the phosphorus adsorbent of the present invention can be mixed with a harmful substance removing agent for removing the harmful substance to thereby form a halogen compound (for example, dioxins and the like). Can be obtained. That is, even if the raw material contains a halogen component such as a chlorine component, it is replaced with a harmless substance (inorganic salt) by the harmful substance remover. Therefore, in the process of producing the phosphorus adsorbent of the present invention, problems of generation of hydrogen chloride, corrosion of equipment, and generation of dioxins do not occur.
[0092]
In addition, the phosphorus recovered by the phosphorus adsorbent of the present invention can be dried, heat-processed, burned and removed the carbon content of the skeleton, etc. by performing processing according to the purpose, as a soil improvement material, fertilizer. It can be directly used, and by incineration and removal of carbon, the phosphorus component can be recovered, so that it can be effectively used as a raw material for various purposes.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a first embodiment of a phosphorus adsorbent according to the present invention.
FIG. 2 is a schematic diagram showing a second embodiment of the phosphorus adsorbent according to the present invention.
FIG. 3 is a schematic view showing an embodiment of a phosphorus recovery tank.
FIG. 4 is a schematic diagram showing a facility for producing the phosphorus adsorbent of the present invention.
FIG. 5 is a schematic configuration diagram of a communication duct provided with crushing means and transport means.
FIG. 6 is a schematic diagram of a phosphorus adsorbent drying treatment facility when a used phosphorus adsorbent is recovered.
FIG. 7 is a schematic diagram of a phosphorus adsorbent treatment facility when a used phosphorus adsorbent is collected.
FIG. 8 is a schematic diagram showing another embodiment of the phosphorus adsorbent heat treatment facility when the used phosphorus adsorbent is recovered.
FIG. 9 is a characteristic diagram showing the phosphorus adsorption performance of Sample 1.
FIG. 10 is a characteristic diagram showing the phosphorus adsorption performance of Sample 2.
FIG. 11 is a characteristic diagram showing the phosphorus adsorption performance of Sample 3.
FIG. 12 is a characteristic diagram showing the phosphorus adsorption performance of Sample 4.
FIG. 13 is a characteristic diagram showing the phosphorus adsorption performance of Sample 5.
FIG. 14 is a schematic diagram of a sewage treatment system based on the activated sludge method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Phosphorus recovery tank, 11 ... Adsorption cartridge, 110 ... Phosphorous adsorbent, 111 ... Storage member, 12 ... Detour plate
2. Drying furnace
3. Crushing means
4: Pyrolysis furnace
5… Crushing means
6 ... Gas combustion furnace
7. Heating furnace
8 Processed processing combustion furnace

Claims (14)

A phosphorus adsorbent comprising an alkali substance component and a carbon component, wherein the skeleton component of the adsorbent is made of a porous carbide, and the alkali component is located on the surface and pore surface. Phosphor adsorbent. A method for producing a phosphorus adsorbent comprising an alkaline substance component and a carbon component,
A phosphorus-free adsorbent containing an alkaline component and a carbon component is obtained by thermally decomposing a raw material containing an alkaline component and a carbon component without containing a harmful substance component by indirect heating. How to generate adsorbent. A method for producing a phosphorus adsorbent comprising an alkaline substance component and a carbon component,
By adding and mixing a harmful substance remover to a raw material containing an alkaline substance component and a carbon component and performing a thermal decomposition treatment by indirect heating, a porous adsorbent containing an alkali component and a carbon component without a harmful substance component can be obtained. A method for producing a phosphorus adsorbent, comprising: A method for recovering a phosphorus component in water to be treated,
The water to be treated is brought into contact with a phosphorus adsorbent containing an alkaline component and a carbon component and having an alkaline component on its surface and pore surface to adsorb and remove the phosphorus component contained in the water to be treated. A method for recovering phosphorus. 5. The method for recovering phosphorus according to claim 4, wherein the phosphorus adsorbent is an adsorption cartridge stored in a water-permeable storage member, and the adsorption cartridge is immersed in the treated water. 6. The phosphorus recovery method according to claim 4, wherein a plurality of adsorption cartridges are detachably arranged to form a phosphorus recovery tank, and the phosphorus recovery tank is provided in a supply line of the water to be treated. 7. The phosphorus according to claim 6, wherein the water to be treated containing the phosphorus component is wastewater derived from the activated sludge method or natural water-based water, and the separated water obtained from the water to be treated is introduced into a phosphorus decomposition tank. Collection method. The phosphorus material according to any one of claims 4 to 7, wherein the adsorbent, which is immersed in the water to be treated and adsorbs and traps a phosphorus component in the water to be treated, is recovered after drying to remove water. Collection method. A method for treating a phosphorus adsorbent that has absorbed a phosphorus component,
A step of drying the phosphorus adsorbent that has absorbed the phosphorus component to remove moisture,
Removing the organic components and moisture contained in the dried adsorbent by indirect heating of the dried adsorbent. A method for treating an adsorbent that has adsorbed a phosphorus component,
A step of drying the phosphorus adsorbent that has absorbed the phosphorus component to remove moisture,
Combusting the dried phosphorus adsorbent to remove carbon components forming the adsorbent. A water treatment method for removing a phosphorus component,
Subjecting the sewage to an anaerobic fermenter to ferment,
A step of subjecting the wastewater subjected to the anaerobic fermentation treatment to a sedimentation basin to perform solid-liquid separation of separated water containing a phosphorus component,
A step of supplying the separated water to a phosphorus recovery tank containing a phosphorus adsorbent containing an alkaline component and a carbon component and having the alkaline component on the surface thereof to adsorb and remove the phosphorus component contained in the separated water. And a water treatment method comprising: A water treatment method for removing a phosphorus component,
A step of subjecting the water to be treated to a sedimentation basin to perform solid-liquid separation of separated water containing a phosphorus component,
A step of supplying the separated water to a phosphorus recovery tank containing a phosphorus adsorbent containing an alkaline component and a carbon component and having the alkaline component on the surface thereof to adsorb and remove the phosphorus component contained in the separated water. And a water treatment method comprising: The water treatment method according to claim 12, wherein the water to be treated is introduced from a natural water system. The phosphorus recovery tank is provided with a plurality of detachable adsorption cartridges in a tank to which the water to be treated is supplied,
14. The water treatment method according to claim 11, wherein the adsorption cartridge stores the adsorbent in a water-permeable storage member.

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