JP2010131499A

JP2010131499A - Sludge dewatering method

Info

Publication number: JP2010131499A
Application number: JP2008308682A
Authority: JP
Inventors: Akira Suzuki; 公鈴木; Kijo Ueno; 紀条上野
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2008-12-03
Filing date: 2008-12-03
Publication date: 2010-06-17
Anticipated expiration: 2028-12-03
Also published as: JP5042975B2

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently reduce the moisture content of dewatered sludge. <P>SOLUTION: In a sludge dewatering method where a dewatering aid for increasing a dewatering effect is added to sludge to turn the sludge dewatered by a dewatering machine 4 to obtain dewatered sludge, the dewatering aid is a non-hydrous material, the non-hydrous material added to the sludge increases the fluidity of the sludge to improve the dewatering effect of the dewatering machine, and the moisture of the sludge is not absorbed by the non-hydrous material and sufficiently dewatered by the dewatering machine, whereby the moisture content of the dewatered sludge can be sufficiently reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、脱水効果を高めるための脱水助剤を汚泥に添加し、これを脱水機で脱水して脱水汚泥を得る汚泥脱水方法に関する。 The present invention relates to a sludge dewatering method in which a dewatering aid for enhancing the dewatering effect is added to sludge, and this is dewatered by a dehydrator to obtain dewatered sludge.

下水汚泥や工場排水汚泥などの汚泥を脱水して得られる脱水汚泥の含水率を低下させるために、以下の特許文献１には、古紙粉砕物を水に分散させて古紙粉砕物スラリーとして汚泥に添加した後、凝集剤を加え凝集汚泥とし、この凝集汚泥を、重力脱水部と加圧脱水部とを循環走行する濾布を備えたベルトプレス型脱水機に供給して脱水処理する方法が開示されている。この方法では、古紙などの繊維状物質を脱水助剤として添加することによって凝集汚泥が滑りにくくなり流動性が低下し、ベルトプレスによる圧搾効果が強められるため、繊維状物質を添加しない場合に比べて脱水汚泥の含水率は低下する。
特開平９−２１６００号公報 In order to reduce the moisture content of dewatered sludge obtained by dewatering sludge such as sewage sludge and industrial wastewater sludge, the following Patent Document 1 describes that waste paper pulverized material is dispersed in water and used as sludge as waste paper pulverized material slurry. After the addition, a coagulant is added to form coagulated sludge, and this coagulated sludge is supplied to a belt press type dehydrator equipped with a filter cloth that circulates between a gravity dehydration unit and a pressure dehydration unit, and a method for dehydration is disclosed. Has been. In this method, by adding a fibrous material such as waste paper as a dehydrating aid, the coagulated sludge becomes less slippery and the fluidity is reduced, and the squeezing effect by the belt press is enhanced, so compared with the case where no fibrous material is added. As a result, the moisture content of the dewatered sludge decreases.
Japanese Patent Laid-Open No. 9-21600

しかしながら、特許文献１のように汚泥に古紙粉砕物などの繊維状物質を添加して脱水処理を行う汚泥脱水方法では、含水率低減効果がさほど大きくなく、脱水汚泥の含水率を十分に低減させることができないという問題があった。 However, in the sludge dewatering method in which a fibrous material such as waste paper pulverized material is added to sludge as in Patent Document 1, the water content reduction effect is not so great, and the water content of the dewatered sludge is sufficiently reduced. There was a problem that I could not.

本発明は、上記問題点を鑑みてなされたものであり、脱水汚泥の含水率を十分に低減させることができる汚泥脱水方法を提供することを目的とする。 This invention is made | formed in view of the said problem, and it aims at providing the sludge dehydration method which can fully reduce the moisture content of a dewatered sludge.

本発明者らは、鋭意努力を重ねた結果、脱水汚泥の含水率には、脱水助剤の内部に吸収され保持される水分が影響していることを見出した。 As a result of intensive efforts, the present inventors have found that the moisture content absorbed and retained inside the dehydration aid affects the moisture content of the dewatered sludge.

そこで、本発明に係る汚泥脱水方法は、上記課題を解決するために、脱水効果を高めるための脱水助剤を汚泥に添加し、これを脱水機で脱水して脱水汚泥を得る汚泥脱水方法において、脱水助剤を非含水性物質としたことを特徴とする。 Therefore, in order to solve the above problems, the sludge dewatering method according to the present invention is a sludge dewatering method in which a dewatering aid for enhancing the dewatering effect is added to sludge, and this is dewatered by a dehydrator to obtain dewatered sludge. The dehydrating aid is a non-hydrous substance.

この方法によれば、非含水性物質が脱水助剤として汚泥に添加されることで、汚泥の流動性が低下し脱水機の脱水効果を高められると共に、汚泥の水分が脱水助剤に吸収されず当該水分を脱水機で十分に脱水され、従って、脱水汚泥の含水率を十分に低減させることができる。 According to this method, the non-hydrous material is added to the sludge as a dehydrating aid, so that the sludge fluidity is reduced and the dehydrating effect of the dehydrator is increased, and the moisture of the sludge is absorbed by the dehydrating aid. Therefore, the water is sufficiently dehydrated by the dehydrator, and therefore the water content of the dewatered sludge can be sufficiently reduced.

ここで、脱水助剤は、中実体であることが好適であり、また、球形であると、均一な脱水効果が得られるため、より好適である。さらに、脱水助剤は、鉄球又はガラス球であることが好適である。 Here, the dehydration aid is preferably a solid substance, and a spherical shape is more preferable because a uniform dehydration effect can be obtained. Further, the dehydrating aid is preferably an iron ball or a glass ball.

本発明に係る汚泥脱水方法によれば、脱水汚泥の含水率を十分に低減させることができる。 According to the sludge dewatering method according to the present invention, the water content of the dewatered sludge can be sufficiently reduced.

以下、本発明による汚泥脱水方法の好適な実施形態について図面を参照しながら説明する。図１は、本発明の一実施形態に係る汚泥脱水方法を適用した汚泥処理装置を示す概略構成図である。 Hereinafter, preferred embodiments of the sludge dewatering method according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a sludge treatment apparatus to which a sludge dewatering method according to an embodiment of the present invention is applied.

汚泥処理装置１００は、助剤混合槽１において、余剰汚泥に脱水効果を高めるための脱水助剤を添加して混合し、この混合物に、無機凝集剤混合槽２において無機凝集剤（ポリ鉄など）を、さらに高分子凝集剤混合槽３において高分子凝集剤（カチオン系など）を順に加え混合して脱水助剤を含む凝集汚泥を得、この凝集汚泥を脱水機４において脱水処理し得られた脱水汚泥を乾燥機５により乾燥し、選別機６において脱水助剤を選別して取り除いた後に、焼却炉７において焼却処理するように構成された装置である。 The sludge treatment apparatus 100 adds and mixes a dewatering aid for enhancing the dewatering effect to the excess sludge in the auxiliary agent mixing tank 1, and mixes the mixture with an inorganic flocculant (such as polyiron) in the inorganic flocculant mixing tank 2. ) And a polymer flocculant (cationic system, etc.) are added in order in the polymer flocculant mixing tank 3 and mixed to obtain agglomerated sludge containing a dehydrating aid, and this agglomerated sludge can be dehydrated in the dehydrator 4. The dewatered sludge is dried by the dryer 5, and the dewatering aid is sorted and removed by the sorter 6, and then incinerated in the incinerator 7.

ここで、特に本実施形態にあっては、汚泥に添加する脱水助剤を、脱水汚泥の含水率を低減すべく、鉄球やビーズ（ガラス球）など、中実体かつ球形（球体）であり、その内部に水分を吸収しない非含水性物質としている。 Here, particularly in the present embodiment, the dehydration aid added to the sludge is solid and spherical (spherical) such as iron balls and beads (glass spheres) in order to reduce the moisture content of the dewatered sludge. It is a non-hydrous material that does not absorb moisture inside.

そして、ここでは、脱水機４として、ベルトプレス型、スクリュープレス型など圧搾脱水するタイプ、または、回転円板を用いて遠心脱水するタイプなどが用いられる。なお、汚泥脱水に適するベルトプレス型などの圧搾タイプを用いるのが特に好適である。 In this case, as the dehydrator 4, a type such as a belt press type or a screw press type that performs pressure dehydration or a type that performs centrifugal dehydration using a rotating disk is used. It is particularly preferable to use a pressing type such as a belt press type suitable for sludge dewatering.

また、ここでは、選別機６として、磁選機、ふるい、比重選別機（風力選別機）などが用いられる。なお、汚泥に添加された脱水助剤が鉄球の場合には、脱水汚泥から鉄を選別できる磁選機を用いるのが好適であり、また、脱水助剤がビーズの場合には、脱水汚泥からビーズを選別できる風力選別機を用いるのが好適である。 Here, as the sorter 6, a magnetic sorter, a sieve, a specific gravity sorter (wind sorter), or the like is used. In addition, when the dehydration aid added to the sludge is an iron ball, it is preferable to use a magnetic separator capable of sorting iron from the dehydrated sludge. It is preferable to use a wind power sorter capable of sorting the beads.

このように構成された汚泥処理装置１００では、助剤混合槽１において、鉄球やビーズ（ガラス球）など非含水性物質が脱水助剤として汚泥に混合されるため、この非含水性物質により脱水機４において凝集汚泥が滑りにくくなり流動性が低下し、脱水機４の脱水効果が向上する。さらに汚泥に混合された非含水性物質が汚泥の水分をその内部に吸収しないため、当該水分を脱水機４で十分に脱水できる。従って、脱水汚泥の含水率を十分に低減させることができる。 In the sludge treatment apparatus 100 configured as described above, in the auxiliary agent mixing tank 1, non-hydrous substances such as iron balls and beads (glass spheres) are mixed with the sludge as dehydration aids. In the dehydrator 4, the agglomerated sludge becomes less slippery and the fluidity is lowered, and the dehydrating effect of the dehydrator 4 is improved. Furthermore, since the non-hydrous material mixed in the sludge does not absorb the moisture of the sludge into the inside thereof, the moisture can be sufficiently dehydrated by the dehydrator 4. Therefore, the moisture content of the dewatered sludge can be sufficiently reduced.

なお、後段の選別機６では、ランニングコストを低減すべく、脱水汚泥から鉄球やビーズなどの脱水助剤が取り除かれ、再び助剤混合槽１に導入され再利用される。 In the latter sorter 6, in order to reduce running costs, dehydration aids such as iron balls and beads are removed from the dewatered sludge, and are again introduced into the auxiliary agent mixing tank 1 and reused.

因みに、本実施形態では、特に好適であるとして、非含水性物質を鉄球やガラス球のように中実体かつ球形としているが、中実体であれば良く、球形であればより良い。 Incidentally, in the present embodiment, the non-hydrous material is solid and spherical like an iron ball or glass sphere as being particularly suitable. However, the solid substance may be solid and spherical.

以下、本発明の効果を確認するために行った脱水試験について、実施例１及び比較例１として説明する。 Hereinafter, the dehydration test performed to confirm the effect of the present invention will be described as Example 1 and Comparative Example 1.

（実施例１）
多孔板の上に配された後述の凝集汚泥を上方から円板で圧搾するハイパープレス試験機を用いて、脱水試験を行った。ハイパープレス試験機の多孔板及び円板の直径は６０ミリメートルとし、圧搾圧力は０．６ＭＰａ、圧搾時間は１０秒とした。また、多孔板及び円板の対向面にはフェルト材のろ布を貼着した。汚泥濃度は１２０００ｍｇ／ｌ以下とした。添加材はガラス製の球形ビーズとし、その球径が０．１、０．４、及び１．０ｍｍの３種類を用いた。無機凝集材はポリ鉄とし、添加量は汚泥中の固形物量に対して１１％とした。また、高分子凝集材はカチオン系高分子凝集剤とし、添加量は汚泥中の固形物量に対して０．１６％とした。脱水試験は、汚泥に添加材と無機凝集剤を加えた汚泥にさらに高分子凝集剤を加え凝集汚泥としてハイパープレス試験機に供し、脱水汚泥の厚みが１ｍｍとなるよう、すなわち多孔板と円板とのろ布間の距離が１ｍｍとなるように凝縮汚泥を圧搾した。 Example 1
A dehydration test was performed using a hyper press tester that squeezes agglomerated sludge described later disposed on the perforated plate with a disk from above. The diameter of the perforated plate and the disc of the hyper press tester was 60 mm, the pressing pressure was 0.6 MPa, and the pressing time was 10 seconds. Further, a felt filter cloth was attached to the opposing surfaces of the perforated plate and the disc. The sludge concentration was 12000 mg / l or less. The additive material was glass spherical beads, and three types with spherical diameters of 0.1, 0.4, and 1.0 mm were used. The inorganic agglomerated material was polyiron, and the amount added was 11% with respect to the amount of solids in the sludge. The polymer flocculant was a cationic polymer flocculant, and the amount added was 0.16% with respect to the amount of solid matter in the sludge. The dehydration test was performed by adding a polymer coagulant to the sludge obtained by adding an additive and an inorganic coagulant to sludge, and providing it as a coagulated sludge to a hyper press test machine, so that the thickness of the dehydrated sludge becomes 1 mm, that is, a perforated plate and a disc The condensed sludge was squeezed so that the distance between the filter cloth and the cloth was 1 mm.

（比較例１）
汚泥に添加材（ビーズ）を加えない点以外は実施例１と同様とした。 (Comparative Example 1)
The same procedure as in Example 1 was performed except that no additive (bead) was added to the sludge.

実施例１は、上記３種類の添加材（球径０．１、０．４、、１．０ｍｍ）を２通りの添加量（２５％、５０％）で汚泥に添加したときの脱水汚泥の含水率をそれぞれ測定した。また、比較例１は、添加材を汚泥に加えずに、無機凝集剤及び高分子凝集剤のみを汚泥に加えたときの脱水汚泥の含水率を測定した。脱水汚泥の含水率は、１０５℃に温調した乾燥機で２時間乾燥後の重量を測定して乾燥前後の重量差から算出した。この測定結果を表１に示す。なお、添加材の添加量は、乾燥汚泥基準、すなわち乾燥汚泥重量に対する割合で表示した。すなわち、添加量１００％とは、乾燥汚泥重量と同じ重量のビーズを添加した状態である。

In Example 1, the above three types of additives (ball diameters 0.1, 0.4, 1.0 mm) were added to sludge in two different addition amounts (25%, 50%). The water content was measured respectively. In Comparative Example 1, the moisture content of the dewatered sludge was measured when only the inorganic flocculant and the polymer flocculant were added to the sludge without adding the additive to the sludge. The moisture content of the dewatered sludge was calculated from the weight difference before and after drying by measuring the weight after drying for 2 hours with a dryer adjusted to 105 ° C. The measurement results are shown in Table 1. In addition, the addition amount of the additive was displayed as a dry sludge standard, that is, a ratio to the dry sludge weight. That is, the addition amount of 100% is a state in which beads having the same weight as the dry sludge weight are added.

表１に示すように、ビーズ（ガラス球）などの非含水性物質を汚泥に添加すると、その添加量が大きいほど、また、その球径が大きいほど、脱水汚泥の含水率が大きく低下することがわかる。なお、球径が１ｍｍより大きいと、脱水機に負荷がかかるため、汚泥に添加する非含水性物質（添加材）の球径は１ｍｍ程度が好ましい。 As shown in Table 1, when non-hydrous substances such as beads (glass spheres) are added to sludge, the water content of dewatered sludge decreases greatly as the amount added increases and the sphere diameter increases. I understand. In addition, since a load will be applied to a dehydrator when the sphere diameter is larger than 1 mm, the sphere diameter of the non-hydrous material (additive) added to the sludge is preferably about 1 mm.

本発明の一実施形態に係る汚泥脱水方法を適用した汚泥処理装置を示す概略構成図である。It is a schematic block diagram which shows the sludge processing apparatus to which the sludge dehydration method which concerns on one Embodiment of this invention is applied.

符号の説明Explanation of symbols

１…助剤混合槽、２…無機凝集剤混合槽、３…高分子凝集剤混合槽、４…脱水機、５…乾燥機、６…選別機、７…焼却炉、１００…汚泥処理装置。
DESCRIPTION OF SYMBOLS 1 ... Auxiliary mixing tank, 2 ... Inorganic flocculant mixing tank, 3 ... Polymer flocculent mixing tank, 4 ... Dehydrator, 5 ... Dryer, 6 ... Sorter, 7 ... Incinerator, 100 ... Sludge processing apparatus.

Claims

脱水効果を高めるための脱水助剤を汚泥に添加し、これを脱水機で脱水して脱水汚泥を得る汚泥脱水方法において、
前記脱水助剤を非含水性物質としたことを特徴とする汚泥脱水方法。 In the sludge dewatering method of adding dewatering aid to the sludge to enhance the dewatering effect and dewatering this with a dehydrator to obtain the dewatered sludge,
A method for dewatering sludge, characterized in that the dehydrating aid is a non-hydrous substance.

前記脱水助剤は、中実体であることを特徴とする、請求項１に記載の汚泥脱水方法。 The sludge dewatering method according to claim 1, wherein the dewatering aid is solid.

前記脱水助剤は、球形であることを特徴とする、請求項２に記載の汚泥脱水方法。 The sludge dewatering method according to claim 2, wherein the dewatering aid is spherical.

前記脱水助剤は、鉄球又はガラス球であることを特徴とする請求項３に記載の汚泥脱水方法。

The sludge dewatering method according to claim 3, wherein the dewatering aid is an iron ball or a glass ball.