JP4160422B2 - Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same - Google Patents
Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same Download PDFInfo
- Publication number
- JP4160422B2 JP4160422B2 JP2003057373A JP2003057373A JP4160422B2 JP 4160422 B2 JP4160422 B2 JP 4160422B2 JP 2003057373 A JP2003057373 A JP 2003057373A JP 2003057373 A JP2003057373 A JP 2003057373A JP 4160422 B2 JP4160422 B2 JP 4160422B2
- Authority
- JP
- Japan
- Prior art keywords
- heavy metal
- ash
- containing ash
- agent
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
【０００１】
【発明の属する技術分野】
本発明は、都市ゴミや産業廃棄物等の焼却プラントからの飛灰のような重金属含有灰を処理する際の重金属固定化剤、及びそれを用いる重金属含有灰の処理方法に関する。
更に、本発明は、重金属含有物、特に都市ゴミや産業廃棄物等の焼却プラントからの飛灰を処理するに際し、重金属固定化剤、及びそれを用いる処理物から重金属等の有害物質が溶出するのを防止する技術に関するものである。
【０００２】
【従来の技術】
都市ゴミや産業廃棄物等の焼却プラントから排出される飛灰は、電気集塵機（以下「ＥＰ」という）やバグフィルター（以下「ＢＦ」という）で捕集されたのち埋め立てされている。しかし、これら飛灰は有害な重金属を多く含んでおり、埋め立て地からの雨水等による鉛、水銀等の溶出は環境汚染の可能性がある。このため飛灰は特別管理廃棄物に指定され、「セメント固化法」、「酸その他の溶剤による抽出法」、「溶融固定化法」又は「薬剤添加法」のいずれかの処理を施した後、廃棄することが義務づけられている。これらのうち薬剤添加法は、他の方法に比べ一般に装置及び取り扱いが簡便なため種々検討されている。
【０００３】
薬剤添加法とは、所定量の水と薬剤と焼却灰とを混練して反応させ、有害な重金属類を固定化する方法である。この目的で用いられる薬剤としては、重金属類とキレート化合物を形成して水に不溶性の安定な固定化物を形成する有機液体キレート系重金属固定化剤、リン酸（塩）、珪酸（塩）、炭酸（塩）、重炭酸（塩）などの無機系重金属固定化剤などが挙げられる。有機液体キレート系重金属固定化剤としては、ジアルキルジチオカルバミン酸のアルカリ金属塩及び／又はジアルキルジチオカルバミン酸基を分子内に２個以上有する化合物のアルカリ金属塩、具体的には、ジエチルジチオカルバミン酸のカリウム塩及び／又はN1，N2，Ｎ3，Ｎ5−テトラ（ジチオカルボキシ）テトラエチレンペンタミンのナトリウム塩及び／又はピペラジンビスジチオカルバミン酸のカリウム塩などがある。これらの有機液体キレート系重金属固定化剤を用いた場合、混練や成形工程でジチオカルバミン酸基が分解して二硫化炭素やアミン類の臭気が発生し、環境、労働安全衛生の観点から問題であった。さらに、このジチオカルバミン酸系の化合物にアミノカルボン酸系キレート剤を合わせた液体キレート剤がある（特許文献１、非特許文献１）。
【０００４】
【特許文献１】
特開２００２−１６６２４７
【非特許文献１】
「飛灰対策−有害物質除去・無害化・再資源化技術」第３７〜４１頁
【０００５】
【発明が解決しようとする課題】
また、上記の有機液体キレート系重金属固定化剤を用いた場合、混練や成形工程でジチオカルバミン酸基が分解し二硫化炭素やアミン類の臭気が発生し、環境・労働安全衛生の観点から問題であった。無機系重金属固定化剤は、有機液体キレート系重金属固定化剤に比べ十分な重金属固定効果が得られなかった。また、排ガス処理（窒素酸化物の低減）として尿素水やアンモニア水を焼却炉に吹き込む場合、排ガス中の成分との反応生成物（例えば塩化アンモニウム）が粉体状で飛灰中に移行し、飛灰中に塩化水素の処理に用いられる消石灰が含まれる場合、重金属処理のため薬剤と水を添加して混練すると、ｐＨがアルカリ側に傾くためアンモニアが追出されて発生するが、上記薬剤では、アンモニア臭気を抑制することができず環境・労働安全衛生の観点から問題であった。
【０００６】
本発明は、上記の課題に鑑みてなされたものであり、目的は、重金属含有物が含水した際に未固定の重金属類が溶出するのを抑制し、臭気の発生を抑制することのできる、新規な重金属固定化剤、並びに及びそれを用いた焼却灰の処理方法を提供するである。
【０００７】
【課題を解決するための手段】
本発明者らは、リン酸マグネシウムアンモニウム（以下「ＭＡＰ」ともいう）を加熱しアンモニアを放出させて得られるリン酸一水素マグネシウム（以下「ＭＨＰ」ともいう）を焼却灰の処理剤として応用することができないかどうかについて鋭意研究した結果、焼却灰処理物からの重金属類、臭気の漏洩を抑制できることを見出し、本発明を完成するに至った。
【０００８】
すなわち、本発明は、下記の手段により前記の課題を解決した。
（１）リン酸マグネシウムアンモニウムの加熱によりアンモニアを放出させて得る多孔質リン酸一水素マグネシウムを必須成分として含むことを特徴とする重金属固定化剤。
（２）前記リン酸一水素マグネシウムを、廃水のリンの回収プロセスにおいて生成されるリン酸マグネシウムアンモニウムから得ることを特徴とする前記（１）に記載の重金属固定化剤。
（３）前記多孔質リン酸一水素マグネシウムを粉砕して粒径を５００μｍ以下とすることを特徴とする前記（１）又は（２）に記載の重金属固定化剤。
【０００９】
なお、本発明の実施態様としては、以下のものがある。
（ａ）廃水を脱リン処理してリン酸マグネシウムアンモニウムが主体の中間物を得る工程、該脱リン工程に次いで該中間物を物理的に脱水する工程、該脱水工程に次いで該物理的に脱水された中間物を約１００℃以上で約６０分以上加熱する工程、とからなるリン酸一水素マグネシウムを少なくとも含む生成物を製造する方法。
（ｂ）前記（ａ）記載の生成物を粉砕して粒径を約５００μｍ以下とする工程を更に含むことを特徴とする多孔質の生成物を製造する方法。
（ｃ）重金属含有灰に上記（ａ）又は（ｂ）記載の生成物及び水を添加して、混練し、灰に含まれる有害物質を固定化することを特徴とする重金属含有灰の処理方法。
【００１０】
すなわち本発明の骨子は、具体的に言うと、リン酸マグネシウムアンモニウム（ＭＡＰ）を加熱しアンモニアを放出させて得られるリン酸一水素マグネシウム（ＭＨＰ）を必須成分として含むことを特徴とする重金属固定化剤及びそれを用いて焼却灰からの重金属の溶出を防止する方法である。
【００１１】
【発明の実施の形態】
以下に本発明を詳細に説明する。
本発明の方法において対象となる重金属含有灰は、特に限定されるものではないが、通常都市ゴミや産業廃棄物の焼却施設から排出され、ＥＰ、ＢＦ、マルチサイクロン等で捕集された煤塵のような飛灰を指す。また、焼却灰、焼却残渣、更に汚染土壌、浚渫土壌なども対象に含まれる。
【００１２】
排ガス処理（窒素酸化物の低減）を目的として、排ガスに尿素水やアンモニア水を焼却炉に吹込む場合、排ガス中の成分との反応生成物（例えば塩化アンモニウム）が粉体状で飛灰中に移行し、飛灰中に消石灰（塩化水素の処理）が含まれる場合、乾燥状態では問題ないが、重金属処理のため薬剤と水を添加して加湿混練すると、ｐＨがアルカリ性側に傾くためアンモニアが追出されて発生する。このアンモニアは、上記排ガス処理に由来すると考えられているが、窒素を多く含むゴミの燃焼によっても生じるものと考えられる。また、重金属処理剤がキレート系の場合、これも高アルカリ性のためアンモニアの発生を助長する。
【００１３】
本発明における、上記の骨子を形成する態様での効果発現のメカニズムについては以下のように考えられる。ＭＡＰを加熱処理するとアンモニア（ＮＨ3）を放出しＭＨＰが得られる（反応式（１））。
（加熱） ＭｇＮＨ4ＰＯ4・６Ｈ2Ｏ（ＭＡＰ）→ＭｇＨＰＯ4（ＭＨＰ）＋６Ｈ2Ｏ↑＋ＮＨ3↑ …反応式（１）
このＭＡＰを加熱することで生成するＭＨＰは、結晶の表面や内部に多孔質を形成し、重金属類やアンモニウムイオン等のカチオン性物質を吸着する機能を有すると考えられる。
【００１４】
本発明に係る重金属固定化剤の焼却灰に対する好ましい添加割合は、焼却灰の重金属含有量、臭気原因物質含有量によって変動するが、焼却灰処理剤の必須成分であるＭＨＰとして０．１重量％以上が好ましく、１〜３０重量％がより好ましい。０．１重量％未満では十分な重金属固定化効果が得られない。更に、本発明においては、上記に説明したＭＨＰを、従来の有機液体キレート系重金属固定化剤、リン酸（塩）、珪酸（塩）、炭酸（塩）、重炭酸（塩）などの無機系重金属固定化剤、硫酸バンド、ポリ塩化アルミニウム（ＰＡＣ）、ポリ硫酸アルミニウム（ＰＡＳ）などのアルミニウム系凝集剤、硫酸第一鉄、硫酸第二鉄、塩化第二鉄、ポリ硫酸鉄などの鉄系凝集剤、セメント、樹脂酸などと組み合わせて用いることも可能である。
【００１５】
本剤（ＭＨＰ）は、市販品以外に排水処理の脱リン工程で排出されるリン酸マグネシウムアンモニウム（ＭＡＰ）、又はリン酸マグネシウムアンモニウム（ＭＡＰ）を含む化合物から製造できる。製造法の一例としてＭＡＰを含む化合物、混合物（純分９０％、粒径０．３〜２ｍｍ）を水切り後１００〜２００℃で６０分以上加熱し、内部の結晶水や揮発分を除去させ、ボールミルで粉砕し分取製造することもできる。本剤（ＭＨＰ）の粒径は１０〜５００μｍが好適である。本発明で用いるＭＨＰの原料となるＭＡＰは、汚泥の嫌気性消化脱離液などの廃水から、リンやアンモニア性窒素をイオン反応による晶析反応を利用して除去する、いわゆるＭＡＰ造粒法、又はリン酸、マグネシウム塩、アンモニウム塩を水中で同モル混合し脱水することで含水率４０〜５０％のものを得ることができる。
【００１６】
リン酸マグネシウムアンモニウム（ＭＡＰ）又はリン酸マグネシウムアンモニウム（ＭＡＰ）を含む化合物を加熱して製造する方法以外に、ミルなどの粉砕機による粉砕、粉末化の過程で摩擦熱により上記化合物からアンモニアや結晶水、その他揮発分をガスとして分離し、上記化合物の表面や内部に多孔質を形成させることができる。上記化合物は、通常、粒状又は破砕状、鱗状であるため重金属固定化剤として使用するには粉末状にすることにより、粉末化と加熱が同じ工程で実施できる。粉砕機には、市販の粉砕機が使用でき、ボールミル、ロールミルなどがある。粉砕機の運転条件は、重金属固定化剤の粒径を０．３ｍｍ以下にする条件で運転すれば、粉末状の重金属固定化剤の温度は数百度になり、本発明の加熱に相当する効果が得られる。
【００１７】
本発明の方法において、前記飛灰混練時の添加水は、あくまで飛灰と重金属固定化剤の他、その他の重金属処理剤（これらを総称して「重金属固定化剤」ということがある）を混練する添加水であり、重金属処理剤との混練状態が充分でない、あるいは処理して得られる飛灰が液状となる等、重金属処理に影響を与えないよう、混練の具合によっては抑制剤の濃度の調整が必要である。特に限定するものではないが、重金属の処理において使用する水の量は、処理した飛灰の廃棄を容易にするため、通常処理する飛灰に対して５〜５０重量％の範囲で使用される。
【００１８】
【実施例】
次に、実施例により本発明をさらに詳細に説明する。但し、本発明は下記の実施例のみに限定されるものではない。
【００１９】
実施例１〜３及び比較例１〜２
（試験方法）
各実施例及び比較例で用いた試験法は以下の通りである。
（１）溶出試験
ＢＦ灰（鉛＝９６０ｐｐｍを含む）１００重量部に対して、水３０重量部を加え、更に所定量の重金属固定化剤を添加して、十分混練して一日間養生した。その後、サンプルを５ｍｍ以下に粉砕し、環境庁告示第１３号試験法に基づいて重金属の溶出試験を行った。
（２）臭気試験
ＢＦ灰（鉛＝９６０ｐｐｍを含む）２０ｇを１リットルのテドラーバックに入れ、水６ｇ（３０ｗ／ｗ％相当）と所定量の重金属固定化剤を添加して十分混練した。さらに空気５００ｍｌを注入して密閉し、５０℃で３０分間加温した後、アンモニア及び二硫化炭素の濃度の測定を行った。
【００２０】
（試験内容）
実施例１〜３及び比較例１〜２の試験内容を以下に示す。なお、ここで使用したＭＨＰは、純水に正りん酸、塩化マグネシウム及びアンモニア水を各々０．００３ｍｏｌ／リットルになるように添加し、水酸化ナトリウムでｐＨ８〜９に調製し、１時間攪拌後、２４時間静置し析出物を沈殿させ、５Ａろ紙で分離し調製したＭＡＰを１０５℃で加熱することにより得たものである。
実施例１
重金属固定化剤としてＭＨＰを３重量部添加し、重金属溶出試験、臭気試験を行った。
実施例２
重金属固定化剤としてＭＨＰを５重量部添加し、重金属溶出試験、臭気試験を行った。
実施例３
重金属固定化剤としてＭＨＰを１０重量部添加し、重金属溶出試験、臭気試験を行った。
【００２１】
比較例１
重金属固定化剤として、ジエチルジチオカルバミン酸カリウム塩を主成分とする有機液体キレート系薬剤（成分濃度５７重量％）を３重量部添加し、重金属溶出試験、臭気試験を行った。
比較例２
硫酸第二鉄を１０重量部添加し、重金属溶出試験、臭気試験を行った。
【００２２】
（試験結果）
実施例１〜３及び比較例１〜２の試験結果を第１表に示す。
【００２３】
【表１】
重金属固定化剤として、本発明に係るＭＨＰを用いて焼却灰を処理した場合（実施例１〜３）、鉛の溶出濃度は埋立基準値（総理府令５号）である０．３ｍｇ／リットル未満を満足し、アンモニア濃度は、有機液体キレートを用いて焼却灰を処理した場合（比較例１）、硫酸第二鉄を用いて焼却灰を処理した場合（比較例２）と比較し大幅に低減した。また、二硫化炭素は、ＭＨＰを用いて焼却灰を処理した場合（実施例１〜３）検出され無かったのに対し、有機液体キレートを用いて焼却灰を処理した場合（比較例１）では検出された。
【００２５】
【発明の効果】
本発明によれば、ＭＨＰを必須成分として含む本発明の重金属固定化剤、及びそれを用いた焼却灰の処理方法によれば、臭気化合物の発生を抑制し、処理焼却灰が含水した際に未固定の重金属類が溶出するのを極めて効率的に抑制することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heavy metal immobilizing agent for treating heavy metal-containing ash such as fly ash from an incineration plant such as municipal waste and industrial waste, and a method for treating heavy metal-containing ash using the same.
Furthermore, in the present invention, when processing heavy ash from incineration plants such as heavy metals, especially municipal waste and industrial waste, toxic substances such as heavy metals are eluted from heavy metal immobilizing agents and processed products using the same. The present invention relates to a technique for preventing the above.
[0002]
[Prior art]
Fly ash discharged from incineration plants, such as municipal waste and industrial waste, is collected by an electric dust collector (hereinafter referred to as “EP”) and a bag filter (hereinafter referred to as “BF”) and then reclaimed. However, these fly ash contains a lot of harmful heavy metals, and elution of lead, mercury, etc. from rainwater from landfills may cause environmental pollution. For this reason, fly ash is designated as a specially managed waste, and after being treated with one of the following methods: “cement solidification method”, “extraction method with acid or other solvent”, “melt fixation method” or “chemical addition method” It is obliged to dispose of it. Among these methods, various methods for adding a drug have been studied because they are generally simpler and easier to handle than other methods.
[0003]
The chemical addition method is a method in which a predetermined amount of water, a chemical and incinerated ash are kneaded and reacted to fix harmful heavy metals. Drugs used for this purpose include organic liquid chelate heavy metal immobilizing agents that form chelate compounds with heavy metals to form a water-insoluble stable immobilization product, phosphoric acid (salt), silicic acid (salt), carbonic acid Inorganic heavy metal fixing agents such as (salt) and bicarbonate (salt). Examples of the organic liquid chelate heavy metal fixing agent include alkali metal salts of dialkyldithiocarbamic acid and / or alkali metal salts of compounds having two or more dialkyldithiocarbamic acid groups in the molecule, specifically, potassium salt of diethyldithiocarbamic acid And / or a sodium salt of N 1 , N 2 , N 3 , N 5 -tetra (dithiocarboxy) tetraethylenepentamine and / or a potassium salt of piperazine bisdithiocarbamic acid. When these organic liquid chelate heavy metal immobilizing agents are used, the dithiocarbamate group is decomposed during the kneading or molding process, and the odor of carbon disulfide and amines is generated, which is a problem from the viewpoint of the environment and occupational health and safety. It was. Furthermore, there is a liquid chelating agent in which an aminocarboxylic acid chelating agent is combined with this dithiocarbamic acid based compound (Patent Document 1, Non-Patent Document 1).
[0004]
[Patent Document 1]
JP 2002-166247 A
[Non-Patent Document 1]
"Flying ash countermeasures-Hazardous substance removal / detoxification / recycling technology", pp. 37-41
[Problems to be solved by the invention]
In addition, when the above organic liquid chelate heavy metal immobilizing agent is used, the dithiocarbamic acid group is decomposed during the kneading or molding process, and the odor of carbon disulfide and amines is generated, which is a problem from the viewpoint of the environment, occupational safety and health. there were. The inorganic heavy metal immobilizing agent did not have a sufficient heavy metal immobilizing effect as compared with the organic liquid chelate heavy metal immobilizing agent. In addition, when urea water or ammonia water is blown into the incinerator for exhaust gas treatment (reduction of nitrogen oxides), the reaction product (for example, ammonium chloride) with components in the exhaust gas moves into fly ash in the form of powder, When fly ash contains slaked lime used for hydrogen chloride treatment, adding chemicals and water for heavy metal treatment and kneading causes the pH to tilt toward the alkali side, and ammonia is expelled. However, ammonia odor could not be suppressed, which was a problem from the viewpoint of environment, occupational safety and health.
[0006]
The present invention has been made in view of the above problems, and the object is to suppress the elution of unfixed heavy metals when the heavy metal-containing material contains water, and to suppress the generation of odors. A novel heavy metal fixing agent and a method for treating incinerated ash using the same.
[0007]
[Means for Solving the Problems]
The present inventors apply magnesium monohydrogen phosphate (hereinafter also referred to as “MHP”) obtained by heating magnesium ammonium phosphate (hereinafter also referred to as “MAP”) to release ammonia as a treatment agent for incineration ash. As a result of earnest research as to whether or not it is possible, it was found that leakage of heavy metals and odors from the incinerated ash-treated product could be suppressed, and the present invention was completed.
[0008]
That is, this invention solved the said subject by the following means.
(1) A heavy metal immobilizing agent comprising porous magnesium monohydrogen phosphate obtained by releasing ammonia by heating magnesium ammonium phosphate as an essential component.
(2) The heavy metal immobilizing agent according to (1), wherein the magnesium monohydrogen phosphate is obtained from magnesium ammonium phosphate produced in a wastewater phosphorus recovery process.
(3) The heavy metal immobilizing agent according to (1) or (2), wherein the porous magnesium monohydrogen phosphate is pulverized to have a particle size of 500 μm or less .
[0009]
Examples of the embodiment of the present invention include the following.
(A) A step of dephosphorizing waste water to obtain an intermediate mainly composed of magnesium ammonium phosphate, a step of physically dehydrating the intermediate following the dephosphorization step, and a physical dehydration subsequent to the dehydration step Heating the resulting intermediate at about 100 ° C. or higher for about 60 minutes or longer, and producing a product containing at least magnesium monohydrogen phosphate.
(B) A method for producing a porous product, further comprising the step of pulverizing the product described in (a) to a particle size of about 500 μm or less.
(C) A method for treating heavy metal-containing ash, comprising adding the product described in (a) or (b) and water to heavy metal-containing ash, kneading, and fixing harmful substances contained in the ash .
[0010]
Specifically, the gist of the present invention specifically includes a heavy metal fixing characterized by containing magnesium monohydrogen phosphate (MHP) obtained by heating magnesium ammonium phosphate (MAP) and releasing ammonia as an essential component. It is a method for preventing elution of heavy metals from incineration ash using an agent.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The heavy metal-containing ash that is a target in the method of the present invention is not particularly limited, but is usually discharged from the incineration facility for municipal waste or industrial waste and collected by EP, BF, multicyclone, etc. Such as fly ash. Also included are incineration ash, incineration residue, contaminated soil, dredged soil, and the like.
[0012]
For the purpose of exhaust gas treatment (reduction of nitrogen oxides), when urea water or ammonia water is blown into the incinerator for the exhaust gas, the reaction product (for example, ammonium chloride) with the components in the exhaust gas is in powder form in the fly ash When slaked lime (hydrogen chloride treatment) is contained in the fly ash, there is no problem in the dry state. However, if the chemical and water are added and humidified and kneaded for heavy metal treatment, the pH will tilt toward the alkaline side, so ammonia. It is generated by being expelled. This ammonia is thought to be derived from the above-described exhaust gas treatment, but is also considered to be generated by combustion of garbage containing a lot of nitrogen. In addition, when the heavy metal treating agent is a chelate type, it also has a high alkalinity, which promotes the generation of ammonia.
[0013]
In the present invention, the mechanism of the effect expression in the aspect for forming the above-mentioned outline is considered as follows. When MAP is heat-treated, ammonia (NH 3 ) is released and MHP is obtained (reaction formula (1)).
(Heating) MgNH 4 PO 4 .6H 2 O (MAP) → MgHPO 4 (MHP) + 6H 2 O ↑ + NH 3 ↑ Reaction formula (1)
The MHP generated by heating the MAP is considered to have a function of forming a porous surface or inside of the crystal and adsorbing a cationic substance such as heavy metals and ammonium ions.
[0014]
The preferred addition ratio of the heavy metal fixing agent according to the present invention to the incineration ash varies depending on the heavy metal content of the incineration ash and the odor-causing substance content, but 0.1 wt% as MHP which is an essential component of the incineration ash treatment agent. The above is preferable, and 1 to 30% by weight is more preferable. If it is less than 0.1% by weight, a sufficient effect of immobilizing heavy metal cannot be obtained. Further, in the present invention, the MHP described above is converted into an inorganic system such as a conventional organic liquid chelate heavy metal fixing agent, phosphoric acid (salt), silicic acid (salt), carbonic acid (salt), bicarbonate (salt), and the like. Heavy metal fixing agent, sulfate band, aluminum-based flocculant such as polyaluminum chloride (PAC), polyaluminum sulfate (PAS), iron-based such as ferrous sulfate, ferric sulfate, ferric chloride, polyiron sulfate It can also be used in combination with a flocculant, cement, resin acid and the like.
[0015]
This agent (MHP) can be manufactured from the compound containing magnesium ammonium phosphate (MAP) discharged | emitted in the dephosphorization process of waste water treatment other than a commercial item, or magnesium ammonium phosphate (MAP). As an example of the production method, a compound containing MAP and a mixture (pure content 90%, particle size 0.3 to 2 mm) are drained and heated at 100 to 200 ° C. for 60 minutes or more to remove internal crystal water and volatile matter, It can also be preparatively manufactured by pulverizing with a ball mill. The particle size of this agent (MHP) is preferably 10 to 500 μm. MAP, which is a raw material for MHP used in the present invention, is a so-called MAP granulation method in which phosphorus and ammonia nitrogen are removed from wastewater such as anaerobic digestion and desorption liquid of sludge using a crystallization reaction by ionic reaction, Alternatively, phosphoric acid, magnesium salt, and ammonium salt can be mixed in water in the same molar amount and dehydrated to obtain a water content of 40 to 50%.
[0016]
In addition to the method of heating and producing a compound containing magnesium ammonium phosphate (MAP) or magnesium ammonium phosphate (MAP), ammonia and crystals from the above compound by frictional heat in the process of pulverization and pulverization with a pulverizer such as a mill. Water and other volatile components can be separated as a gas to form a porous surface or inside the compound. Since the above compounds are usually granular, crushed, or scaly, powdering and heating can be carried out in the same step by using powders for use as a heavy metal fixing agent. As the pulverizer, a commercially available pulverizer can be used, and examples thereof include a ball mill and a roll mill. If the operation condition of the pulverizer is operated under the condition that the particle size of the heavy metal fixing agent is 0.3 mm or less, the temperature of the powdered heavy metal fixing agent becomes several hundred degrees, and the effect corresponding to the heating of the present invention Is obtained.
[0017]
In the method of the present invention, the added water at the time of kneading the fly ash is not only fly ash and heavy metal fixing agent, but also other heavy metal treatment agents (these may be collectively referred to as “heavy metal fixing agent”). Additive water to be kneaded, the concentration of the inhibitor depending on the condition of kneading so as not to affect the heavy metal treatment, such as the kneading state with the heavy metal treatment agent is insufficient or the fly ash obtained by treatment becomes liquid. Adjustment is required. Although it does not specifically limit, The quantity of the water used in the process of heavy metal is used in the range of 5 to 50 weight% with respect to the fly ash to process normally, in order to make easy disposal of the processed fly ash. .
[0018]
【Example】
Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
[0019]
Examples 1-3 and Comparative Examples 1-2
(Test method)
The test methods used in each example and comparative example are as follows.
(1) Dissolution test To 100 parts by weight of BF ash (including lead = 960 ppm), 30 parts by weight of water was added, and a predetermined amount of heavy metal immobilizing agent was further added, kneaded sufficiently and cured for one day. Thereafter, the sample was pulverized to 5 mm or less, and a heavy metal dissolution test was conducted based on the Environmental Agency Notification No. 13 test method.
(2) Odor test 20 g of BF ash (containing lead = 960 ppm) was placed in a 1 liter Tedlar bag, and 6 g of water (equivalent to 30 w / w%) and a predetermined amount of heavy metal fixing agent were added and kneaded sufficiently. Further, 500 ml of air was injected and sealed, and after heating at 50 ° C. for 30 minutes, the concentrations of ammonia and carbon disulfide were measured.
[0020]
(contents of the test)
Test contents of Examples 1 to 3 and Comparative Examples 1 and 2 are shown below. The MHP used here was prepared by adding normal phosphoric acid, magnesium chloride, and aqueous ammonia to pure water to 0.003 mol / liter, adjusting the pH to 8-9 with sodium hydroxide, and stirring for 1 hour. The MAP prepared by allowing to stand for 24 hours to precipitate the precipitate, separating it with 5A filter paper, was heated at 105 ° C.
Example 1
As a heavy metal fixing agent, 3 parts by weight of MHP was added, and a heavy metal elution test and an odor test were performed.
Example 2
As a heavy metal fixing agent, 5 parts by weight of MHP was added, and a heavy metal elution test and an odor test were performed.
Example 3
10 parts by weight of MHP was added as a heavy metal fixing agent, and a heavy metal elution test and an odor test were performed.
[0021]
Comparative Example 1
As a heavy metal immobilizing agent, 3 parts by weight of an organic liquid chelating agent (component concentration 57% by weight) mainly composed of potassium diethyldithiocarbamate was added, and a heavy metal elution test and an odor test were performed.
Comparative Example 2
10 parts by weight of ferric sulfate was added, and a heavy metal elution test and an odor test were performed.
[0022]
(Test results)
The test results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.
[0023]
[Table 1]
When incineration ash is treated using the MHP according to the present invention as a heavy metal fixing agent (Examples 1 to 3), the lead elution concentration is less than 0.3 mg / liter, which is the landfill standard value (Prime Ministerial Ordinance No. 5) The ammonia concentration is greatly reduced when incinerated ash is treated with an organic liquid chelate (Comparative Example 1) and when incinerated ash is treated with ferric sulfate (Comparative Example 2). did. Carbon disulfide was not detected when incineration ash was treated with MHP (Examples 1 to 3), whereas incineration ash was treated with organic liquid chelate (Comparative Example 1). was detected.
[0025]
【The invention's effect】
According to the present invention, according to the heavy metal immobilizing agent of the present invention containing MHP as an essential component and the incineration ash treatment method using the same, the generation of odorous compounds is suppressed, and the treated incineration ash contains water. The elution of unfixed heavy metals can be suppressed very efficiently.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003057373A JP4160422B2 (en) | 2003-03-04 | 2003-03-04 | Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003057373A JP4160422B2 (en) | 2003-03-04 | 2003-03-04 | Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2004261773A JP2004261773A (en) | 2004-09-24 |
| JP4160422B2 true JP4160422B2 (en) | 2008-10-01 |
Family
ID=33120818
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003057373A Expired - Fee Related JP4160422B2 (en) | 2003-03-04 | 2003-03-04 | Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4160422B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005230657A (en) * | 2004-02-18 | 2005-09-02 | Ebara Engineering Service Co Ltd | Treatment method for incineration fly ash and treatment agent |
| CN107150060B (en) * | 2017-05-08 | 2022-06-24 | 天津壹鸣环境科技股份有限公司 | Method and system for treating high-concentration fly ash generated by burning household garbage by filling mold bags through wet method |
-
2003
- 2003-03-04 JP JP2003057373A patent/JP4160422B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004261773A (en) | 2004-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107537129A (en) | A kind of heavy metal stabilizer and its application method for administering incineration of refuse flyash | |
| JPH09234450A (en) | Immobilizing method for heavy metal in fly ash | |
| JP4363657B2 (en) | Method and apparatus for stabilizing incineration fly ash | |
| JP4529191B2 (en) | Heavy metal stabilization treatment method, heavy metal stabilizer | |
| JP2005288378A (en) | Treatment method of contaminated medium including heavy metals and treatment agent | |
| Huang et al. | Synthesis and efficiency of a new chemical fixation agent for stabilizing MSWI fly ash | |
| JP4160422B2 (en) | Heavy metal immobilizing agent for heavy metal-containing ash and method for treating heavy metal-containing ash using the same | |
| JP2006015290A (en) | Fixing method for heavy metal in fly ash using no mixing nor kneading apparatus | |
| JPH10137716A (en) | Waste treating material and treatment of waste | |
| JP4567650B2 (en) | Acid waste treatment agent | |
| JPH09239339A (en) | Waste treating material and treatment of waste | |
| JP2008264627A (en) | Waste treatment material and treatment method for detoxifying fly ash (soot and dust) and burned ash or the like | |
| JP5160759B2 (en) | Heavy metal dissolution inhibitor | |
| JP2003181411A (en) | Heavy metal elution preventing agent and treatment method of contaminated medium | |
| JP2004209372A (en) | Heavy metal elution inhibitor and heavy metal elution inhibiting method | |
| JP2013193039A (en) | Heavy metal fixing agent used for incineration fly ash and stabilization treatment method of the incineration fly ash | |
| JPH0679254A (en) | Treating method to make fly ash harmless | |
| JP2005230657A (en) | Treatment method for incineration fly ash and treatment agent | |
| JP4061253B2 (en) | Method for producing heavy metal treatment agent | |
| JP4476110B2 (en) | Heavy metal scavengers containing morpholine dithiocarbamic acid alkali metal salts | |
| JP4259270B2 (en) | Incineration main ash treatment method | |
| JPH01262978A (en) | Method for immoblizing lead and cadmium in solid residue generated by incineration of waste using lime and phosphate | |
| JP2004261774A (en) | Heavy metals elution preventing agent and heavy metals elution preventing method using the agent | |
| JP2006281065A (en) | Sludge modifying agent | |
| JPH0217228B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060303 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20060325 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20071126 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20071127 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20071205 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080204 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080416 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080616 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080709 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080717 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110725 Year of fee payment: 3 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110725 Year of fee payment: 3 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110725 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120725 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120725 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130725 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |