JP2006297238A

JP2006297238A - Flocculation and sedimentation treatment method for sewage, food waste water or the like by recovered flocculant from service water sludge

Info

Publication number: JP2006297238A
Application number: JP2005120382A
Authority: JP
Inventors: Seiichi Ishikawa; 精一石川; Yuji Okumura; 裕司奥村; Yoshikazu Iida; 義和飯田
Original assignee: Kitakyushu Foundation for Advancement of Industry Science and Technology
Current assignee: Kitakyushu Foundation for Advancement of Industry Science and Technology
Priority date: 2005-04-18
Filing date: 2005-04-18
Publication date: 2006-11-02

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flocculation and sedimentation treatment method for removing a substance such as COD, nitrogen and phosphorus, and a chemical substance such as an agricultural chemical or the like by flocculating and settling a suspended matter in sewage, food waste water or the like by a recovered flocculant from service water sludge. <P>SOLUTION: The flocculation and sedimentation, or floatation treatment method for the sewage, the food waste water or the like by the recovered flocculant from the service water sludge carries out flocculation and sedimentation, or floatation treatment of the suspended matter in the sewage, the food waste water, water in waste material disposal facilities or the like in an area of pH of 5 or higher using the recovered flocculant obtained by flocculation of the suspended matter in raw water, flocculation for obtaining clear service water by carrying out sedimentation treatment and acid treatment of sludge generated from a sedimentation treatment process by sulfuric acid or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、原水中の懸濁物質を凝集・沈澱処理して清澄な上水を得るプロセスから発生する汚泥（以下、上水汚泥と称する。）に酸を加え撹拌して得られる回収凝集剤を用いる、下水、食品系廃水等における懸濁物質を凝集・沈澱処理或は浮上処理する方法に関する。 The present invention relates to a recovered flocculant obtained by adding and stirring an acid to sludge generated from a process of obtaining a clear clean water by agglomerating and precipitating a suspended substance in raw water (hereinafter referred to as clean water sludge). The present invention relates to a method for agglomeration / precipitation treatment or levitation treatment of suspended substances in sewage, food wastewater, etc.

従来、原水中の懸濁物質を凝集・沈澱させて清澄な上水を得るべく、凝集剤として硫酸バンド（礬土）やＰＡＣ（ポリ塩化アルミニウム：poly aluminum chloride）を用いて懸濁物質を凝結させるとともに凝集フロックを成長、沈澱させ、沈澱した汚泥を回収して処理するかあるいは土壌改良材等として利用することがなされている。 Conventionally, in order to obtain a clear clean water by agglomerating and precipitating suspended substances in raw water, the suspended substances are condensed using a sulfate band (powder) or PAC (poly aluminum chloride) as a coagulant. In addition, agglomerated flocs are grown and settled, and the precipitated sludge is collected and treated or used as a soil conditioner or the like.

一方、原水中の懸濁物質の凝集・沈澱プロセスにおいて発生する汚泥に硫酸、塩酸といった鉱酸を添加・撹拌しｐＨ：３〜４として、汚泥に含まれる水酸化アルミニウムをＡｌ^３＋やアルミニウムのポリイオン等にイオン化してこれを凝集剤として再利用することが提案されている（たとえば、特許文献１参照）。
特開平０２−１５７００５号公報 On the other hand, mineral acids such as sulfuric acid and hydrochloric acid are added to and stirred in sludge generated in the process of agglomeration / precipitation of suspended solids in raw water to adjust the pH to 3 to 4, and aluminum hydroxide contained in the sludge is converted to Al ³⁺ or aluminum polyions. It has been proposed to ionize and recycle this as a coagulant (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 02-157005

処で、原水中の懸濁物質の凝集・沈澱プロセスにおいて発生する上水汚泥は、前記凝集・沈澱プロセスにおける処理対象が比較的清浄な環境水であるために、汚濁成分や有害成分が少なく、凝集剤の回収、再利用にとって好ましい。 By the way, the water sludge generated in the aggregation / precipitation process of suspended substances in the raw water is a relatively clean environmental water to be treated in the aggregation / precipitation process, so there are few pollutants and harmful components, It is preferable for the recovery and reuse of the flocculant.

上記特許文献１に開示されているように、原水中の懸濁物質の凝集・沈澱プロセスにおいて発生する汚泥に硫酸、塩酸といった鉱酸を添加・撹拌して凝集剤を回収する方法は既知である。しかしながら、上水汚泥からの回収凝集剤を用いて下水、食品系廃水等における懸濁物質の凝集・沈澱を行い、窒素、燐といった「あおこ」多量発生の原因となる栄養塩類を除去する手段は提案されていない。 As disclosed in Patent Document 1, a method for recovering a flocculant by adding and stirring a mineral acid such as sulfuric acid and hydrochloric acid to sludge generated in a coagulation / precipitation process of suspended substances in raw water is known. . However, a means to remove nutrients that cause abundant generation of "Ako" such as nitrogen and phosphorus by aggregating and precipitating suspended substances in sewage and food wastewater using recovered flocculant from drinking water sludge Has not been proposed.

本発明は、原水中の懸濁物質を凝集・沈澱処理して清澄な上水を得るプロセスから発生する上水汚泥に酸を加え撹拌して得られる回収凝集剤を用いて、下水、食品系廃水等における懸濁物質を凝集・沈澱処理して、ＣＯＤ、窒素、燐といった物質や農薬等の化学物質を除去する凝集・沈澱処理方法を提供することを目的とする。 The present invention uses a recovered flocculant obtained by adding and stirring an acid to a water sewage sludge generated from a process of agglomerating and precipitating suspended solids in raw water to obtain a clear sewage. It is an object of the present invention to provide a coagulation / precipitation treatment method for removing substances such as COD, nitrogen and phosphorus and chemical substances such as agricultural chemicals by coagulating and precipitating suspended substances in waste water and the like.

上記課題を解決するための本発明は、原水中の懸濁物質を凝集・沈澱処理して清澄な上水を得る凝集・沈澱処理プロセスから発生する汚泥に硫酸等を添加、撹拌してｐＨ：３〜５として得られる回収凝集剤を用いて、下水、食品系廃水、廃棄物処分場内水等における懸濁物質の凝集・沈澱処理をｐＨ：５以上の領域で行うことを特徴とする上水汚泥からの回収凝集剤による下水、食品系廃水等の凝集・沈澱処理方法または浮上処理する方法である。 In order to solve the above problems, the present invention adds sulfuric acid or the like to sludge generated from a coagulation / precipitation treatment process in which a suspended substance in raw water is coagulated / precipitation to obtain a clear clean water, and stirred to adjust the pH: 3) Water collected by using the recovered flocculant obtained as 3 to 5 to perform flocculation / precipitation treatment of suspended solids in sewage, food waste water, waste disposal site water, etc. in a pH of 5 or more. It is a method of agglomeration / precipitation treatment or levitation treatment of sewage, food wastewater, etc. by a flocculant recovered from sludge.

本発明によれば、たとえば下水処理場流入水を凝集・沈澱処理対象とする場合、ＣＯＤの約６７％、全窒素（Ｔ−Ｎ）の約３０％、全燐（Ｔ−Ｐ）の約９９％を除去することができる。このように、特に燐の除去効果に優れている。これらは、硫酸バンド（礬土）やＰＡＣ（何れも新規購入品）を上回る効果である。 According to the present invention, for example, when the inflow water of a sewage treatment plant is subject to agglomeration / precipitation treatment, about 67% of COD, about 30% of total nitrogen (TN), and about 99 of total phosphorus (TP). % Can be removed. Thus, it is particularly excellent in phosphorus removal effect. These effects are superior to those of sulfuric acid bands (kneaded clay) and PAC (both newly purchased products).

また、本発明によるときは、農薬類をはじめ諸種の化学物質の除去効果にも優れている。 Further, according to the present invention, the effect of removing various chemical substances including agricultural chemicals is also excellent.

本発明は、上水汚泥に硫酸、塩酸といった鉱酸を添加して撹拌し、ｐＨ：３〜５好ましくはｐＨ：３〜４として上水汚泥中のＡｌ（ＯＨ）_３をＡｌ^３＋やアルミニウムのポリイオン等にイオン化した上澄みを回収し、この上澄み液を凝集剤として下水、食品系廃水等における懸濁物質、化学物質の凝集・沈澱処理或いは浮上処理に再利用するものである。 In the present invention, mineral acid such as sulfuric acid and hydrochloric acid is added to the water sludge and stirred, and the pH is 3 to 5, preferably pH 3 to 4, and the Al (OH) ₃ in the water sludge is replaced with Al ³⁺ or aluminum. The supernatant ionized into polyion or the like is collected, and the supernatant is reused as a flocculant for agglomeration / precipitation treatment or suspension treatment of suspended substances or chemical substances in sewage, food wastewater or the like.

上水汚泥からの凝集剤回収条件については、上水汚泥：２ｇ〜１０ｇ（湿）を精製水５０ｍＬに分散させ、１．８Ｎ硫酸で滴定してｐＨの変化から適正凝集剤回収条件を定めた。上水汚泥（湿）の量２ｇ、５ｇ、１０ｇの３水準をパラメータとして、１．８Ｎの硫酸で滴定したときの滴定硫酸量（ｍＬ）とｐＨの関係を図１に示す。図１から明らかなように、滴定硫酸量：３ｍＬ以上でｐＨは３．０〜４．０の範囲でほぼ一定している。本発明においては、硫酸バンドおよびＰＡＣのｐＨ規格が各々３．０以上、３．５〜５．０であることに鑑み、回収凝集剤のｐＨを３．０〜５．０の範囲とした。 Regarding the conditions for recovering the flocculant from the water sludge, the water fludge: 2 g to 10 g (wet) was dispersed in 50 mL of purified water and titrated with 1.8 N sulfuric acid to determine the appropriate flocculant recovery conditions from the change in pH. . FIG. 1 shows the relationship between the titrated sulfuric acid amount (mL) and pH when titrated with 1.8 N sulfuric acid using three levels of 2 g, 5 g and 10 g of water sludge (wet) as parameters. As is apparent from FIG. 1, the titrated sulfuric acid amount is 3 mL or more, and the pH is substantially constant in the range of 3.0 to 4.0. In the present invention, the pH of the recovered flocculant is set in the range of 3.0 to 5.0 in view of the pH standards of the sulfate band and PAC being 3.0 or more and 3.5 to 5.0, respectively.

次に、上水汚泥からの回収凝集剤を用いての、廃棄物処分場内水における懸濁物質の凝集・沈澱処理を行うときのｐＨ条件について説明する。処理対象とした廃棄物処分場内水は、Ｋ市の海面埋立て廃棄物処分場内水（ｐＨ：７．５、ＣＯＤ：１７．０ｍｇ／Ｌ〜２３．５ｍｇ／Ｌ、全窒素（Ｔ−Ｎ）：５．７ｍｇ／Ｌ〜７．２ｍｇ／Ｌ、全燐（Ｔ−Ｐ）：０．１１ｍｇ／Ｌである。発明者らは、この海面埋立て廃棄物処分場内水を処理対象とし上水汚泥からの回収凝集剤量を１０ｍＬ／Ｌとして、懸濁物質の凝集・沈澱処理におけるｐＨ条件を調べた。 Next, a description will be given of the pH conditions when performing the coagulation / precipitation treatment of the suspended solids in the waste disposal site water using the coagulant recovered from the water sludge. The water in the waste disposal site to be treated is the water in the landfill waste disposal site in K City (pH: 7.5, COD: 17.0 mg / L to 23.5 mg / L, total nitrogen (TN) : 5.7 mg / L to 7.2 mg / L, Total phosphorus (TP): 0.11 mg / L The inventors treated the water in this landfill waste disposal site as the treatment target, and treated water sludge. The amount of the flocculant recovered from was set to 10 mL / L, and the pH conditions in the flocculation / precipitation treatment of the suspended substance were examined.

回収凝集剤（液）は、ｐＨ：３．３、Ａｌ：５，８００ｍｇ／Ｌ、ＣＯＤ：９７４ｍｇ／Ｌ、全窒素（Ｔ−Ｎ）：６０．０ｍｇ／Ｌ、および全燐（Ｔ−Ｐ）：１４６ｍｇ／Ｌで、回収凝集剤自身、海面埋立て廃棄物処分場内水に比し高濃度のＣＯＤやＴ−Ｎ、Ｔ−Ｐを含んでおり、図２に示すように、Ｔ−Ｎの除去率に対するｐＨの影響は明確ではなかったが、Ｔ−Ｐの除去率は、ｐＨ：５以上で顕著に向上している。 The recovered flocculant (liquid) is pH: 3.3, Al: 5,800 mg / L, COD: 974 mg / L, total nitrogen (TN): 60.0 mg / L, and total phosphorus (TP) 146mg / L, the recovered flocculant itself contains higher concentrations of COD, TN, and TP than the water in the landfill waste disposal site. As shown in FIG. Although the influence of pH on the removal rate was not clear, the removal rate of TP was remarkably improved at pH: 5 or more.

上記Ｋ市の海面埋立て廃棄物処分場内水およびＫ市下水処理場流入水（ｐＨ：７．５、ＣＯＤ：４４．０ｍｇ／Ｌ〜７９．６ｍｇ／Ｌ、全窒素（Ｔ−Ｎ）：３１．４ｍｇ／Ｌ〜３３．０ｍｇ／Ｌ、全燐（Ｔ−Ｐ）：２．７ｍｇ／Ｌ〜３．２９ｍｇ／Ｌ）における懸濁物質を、上水汚泥からの回収凝集剤によって凝集・沈澱処理した。 Water in landfill waste disposal site in K city and inflow water in K city sewage treatment plant (pH: 7.5, COD: 44.0 mg / L to 79.6 mg / L, total nitrogen (TN): 31 (4 mg / L to 33.0 mg / L, total phosphorus (TP): 2.7 mg / L to 3.29 mg / L) did.

（凝集・沈澱処理における調査項目）
ｐＨ、ＣＯＤ、Ｔ−Ｎ、Ｔ−Ｐ、農薬類等、汚泥沈降速度、および汚泥濾過速度について調べた。農薬類等については、有機塩素系農薬１２種類、有機燐系農薬２１種類、カルバメート系農薬９種類、含窒素系農薬５７種類、ピレスロイド系農薬８種類、その他の農薬５種類、および農薬の分解物５種類の計１１７種類を対象とした。 (Investigation items for coagulation / precipitation treatment)
The pH, COD, TN, TP, agricultural chemicals, sludge sedimentation rate, and sludge filtration rate were examined. For pesticides, 12 types of organochlorine pesticides, 21 types of organophosphorus pesticides, 9 types of carbamate pesticides, 57 types of nitrogen-containing pesticides, 8 types of pyrethroid pesticides, 5 types of other pesticides, and degradation products of pesticides A total of 117 types of 5 types were targeted.

（試薬）
硫酸バンドは林純薬工業（株）特級品を、ＰＡＣはＫ市浄水場で使用しているもの（Ａｌ_２Ｏ_３として１２．０％）を用いた。農薬類等標準品は、林純薬工業（株）、和光純薬工業（株）、Ｒｉｅｄｅｌ−ｄｅＨａёｎ社およびDr.Ehrenstorfer社製の農薬分析用標準品等を用いた。それぞれの農薬はアセトン、トルエンまたはメチルアルコールで溶解して１，０００ｍｇ／Ｌの標準原液を作製し、この標準原液をアセトンまたはメタノールで適宜希釈し、混合標準液を調製した。有機溶媒は、和光純薬工業（株）または関東化学（株）製の残留農薬分析用を用いた。塩化ナトリウムおよび無水硫酸ナトリウムは、市販特級品を７００℃で６時間加熱処理したものを用いた。その他の試薬は市販特級品を用いた。精製水は、日本ミリポア（株）製Milli-QSP超純水装置による精製水を用いた。 (reagent)
The sulfuric acid band used was Hayashi Junyaku Kogyo Co., Ltd. special grade, and the PAC used at K City Water Treatment Plant (Al ₂ O ₃ as 12.0%) was used. Standard products for agricultural chemicals and the like used were standard products for analysis of agricultural chemicals manufactured by Hayashi Pure Chemical Industries, Ltd., Wako Pure Chemical Industries, Ltd., Riedel-de Hann and Dr. Ehrenstorfer. Each agricultural chemical was dissolved in acetone, toluene or methyl alcohol to prepare a standard stock solution of 1,000 mg / L, and this standard stock solution was appropriately diluted with acetone or methanol to prepare a mixed standard solution. As the organic solvent, a residual agricultural chemical analysis manufactured by Wako Pure Chemical Industries, Ltd. or Kanto Chemical Co., Ltd. was used. Sodium chloride and anhydrous sodium sulfate used were those obtained by heat-treating a commercially available special grade product at 700 ° C. for 6 hours. As other reagents, commercially available special grades were used. As purified water, purified water by Milli-QSP ultrapure water device manufactured by Nihon Millipore Corporation was used.

（装置）
ジャーテスターは宮本理研工業（株）製Water Cohesion Reaction Tester JT-6Dを用いた。Ｔ−Ｎ計は東京化成工業（株）製TCI-NOX １０００、GASTORR GT-１０２、VISIBLE DETECTOR S-３２５０およびAUTO SAMPLER SS-３６００を、分光光度計は（株）日立製作所製Ｕ―２０００Ａを用いた、ＧＣ／ＭＳ（ガスクロマトグラフィー／質量分析）装置はヒューレットパッカード社製５８９０ Series Plus／日本電子（株）製Automass system を用いた。 (apparatus)
The jar tester used was Water Cohesion Reaction Tester JT-6D manufactured by Miyamoto Riken Kogyo Co., Ltd. TN meter is TCI-NOX 1000, GASTORR GT-102, VISIBLE DETECTOR S-3250 and AUTO SAMPLER SS-3600 manufactured by Tokyo Chemical Industry Co., Ltd., and U-2000A manufactured by Hitachi, Ltd. is used for the spectrophotometer. The GC / MS (gas chromatography / mass spectrometry) apparatus used was 5890 Series Plus manufactured by Hewlett-Packard Company / Automass system manufactured by JEOL Ltd.

（分析方法）
ｐＨ、ＣＯＤ、Ｔ−Ｎ、およびＴ−ＰはＪＩＳＫ０１０２に規定される方法で測定した。農薬類等は、被検水２００ｍＬを取り、塩化ナトリウム８０ｇを加えてジクロロメタン５０ｍＬで２回抽出し、無水硫酸ナトリウムで脱水、濃縮後、メチルアルコールで全量を２ｍＬとしてＧＣ／ＭＳ法によって測定した。 (Analysis method)
pH, COD, TN, and TP were measured by methods defined in JIS K0102. For agricultural chemicals, 200 mL of test water was taken, 80 g of sodium chloride was added, extracted twice with 50 mL of dichloromethane, dehydrated and concentrated with anhydrous sodium sulfate, and the total amount was measured with GC / MS method with 2 mL of methyl alcohol.

回収凝集剤を用いての廃棄物処分場内水、下水処理場流入水を対象（試料水）とする、懸濁物の凝集・沈澱処理を以下のようにして行った。即ち、試料水１Ｌをビーカーに取り、ジャーテスターを用いて、１５０ｒｐｍで１分間撹拌後１５分間静置、および５０ｒｐｍで１０分間撹拌後１５分間静置し、然る後、１μｍＧＦＰ(glass filter paper)で濾過した濾液について、上記各項目を測定した。 Aggregation / precipitation of the suspension was performed as follows, using the recovered flocculant as water (sample water) in waste disposal site water and sewage treatment plant inflow water. That is, 1 L of sample water was taken in a beaker and stirred for 1 minute at 150 rpm and then left for 15 minutes using a jar tester and left for 15 minutes after stirring for 10 minutes at 50 rpm, and then 1 μm GFP (glass filter paper) Each of the above items was measured for the filtrate filtered through (1).

農薬類等の凝集・沈澱処理は、５Ｌの共栓付三角フラスコに各５ｍｇ／Ｌの混合標準液４０ｍＬを入れ、有機溶媒を除去した後下水処理場流入水４Ｌを加えて十分撹拌したものを試料水（各０．０５ｍｇ／Ｌ添加）として行った。 For agglomeration / precipitation treatment of agricultural chemicals, etc., put 40 mL of 5 mg / L mixed standard solution in a 5 L Erlenmeyer flask with a stopper, remove the organic solvent, add 4 L of influent water from the sewage treatment plant and stir well. It was performed as sample water (0.05 mg / L each added).

なお、上水汚泥からの回収凝集剤と硫酸バンドやＰＡＣとの凝集・沈澱処理効果の比較は、ｐＨを６．０に設定しまた、農薬類等の凝集・沈澱処理効果は下水処理場流入水を用いてｐＨを６．０に設定し、回収凝集剤量０．１ｍＬ／Ｌおよび２ｍＬ／Ｌ、硫酸バンド量５ｍｇ／Ｌおよび５０ｍｇ／Ｌ、ＰＡＣ量５ｍｇ／Ｌおよび５０ｍｇ／Ｌで行った。 For comparison of the coagulation / precipitation treatment effect of the flocculant recovered from the water sludge and the sulfuric acid band or PAC, the pH is set to 6.0, and the coagulation / precipitation treatment effect of agricultural chemicals etc. enters the sewage treatment plant. The pH was set to 6.0 using water, and the collected flocculant amount was 0.1 mL / L and 2 mL / L, the sulfate band amount was 5 mg / L and 50 mg / L, and the PAC amount was 5 mg / L and 50 mg / L. .

上水汚泥からの凝集剤回収過程における汚泥の沈降速度を、以下のようにして調べた。即ち、上水汚泥１０ｇ（湿）に精製水５０ｍＬ〜８０ｍＬを加えて分散させ、次いで硫酸を加えてｐＨ：３．３とした後１００ｍＬ共栓付メスシリンダーに移し精製水で全量を１００ｍＬとした後、１５回強振、続いて１５回弱振し、静置して界面位置の経時変化を調べた。また、静置１時間後に上澄み液３０ｍＬ〜６２ｍＬ（限界量）を分取した残留液に水酸化ナトリウムを加えてｐＨ：７．０に調整し、精製水で全量を１００ｍＬとした後１５回強振、続いて１５回弱振し、同様に沈降速度を調べた。 The sludge settling rate in the process of collecting the flocculant from the water sludge was examined as follows. That is, 50 g to 80 mL of purified water was added to 10 g (wet) of water sludge to disperse, and then sulfuric acid was added to adjust the pH to 3.3, and then transferred to a 100 mL stoppered measuring cylinder to make the total volume 100 mL with purified water. Thereafter, the sample was vibrated 15 times and then weakly 15 times, and then allowed to stand to examine the change of the interface position with time. Further, after 1 hour of standing, sodium hydroxide was added to the residual liquid from which 30 mL to 62 mL (limit amount) of the supernatant was collected to adjust the pH to 7.0, and the total volume was adjusted to 100 mL with purified water, and then shaken 15 times. Subsequently, the sample was shaken slightly 15 times, and the sedimentation rate was examined in the same manner.

上水汚泥からの凝集剤回収過程における汚泥の濾過速度を、以下のようにして調べた。即ち、沈降速度試験後の汚泥分散液をＰＹＲＥＸ（登録商標）６０ロート（漏斗）（上部径：１０ｃｍ、高さ：９ｃｍ、管の長さ：１０ｃｍ、８条の溝付）にＮｏ．５Ａ濾紙（径：１８．５ｃｍ）を敷いて濾過し、濾過液量の経時変化を調べた。 The sludge filtration rate in the process of collecting the flocculant from the water sludge was examined as follows. That is, the sludge dispersion liquid after the sedimentation rate test was transferred to a PYREX (registered trademark) 60 funnel (upper diameter: 10 cm, height: 9 cm, tube length: 10 cm, with 8 grooves). 5A filter paper (diameter: 18.5 cm) was spread and filtered, and the change over time in the amount of filtrate was examined.

上水汚泥からの回収凝集剤を用いての、廃棄物処分場内水および下水処理場流入水における懸濁物質の凝集・沈澱処理効果を調べた。その際、硫酸バンド及びＰＡＣとの比較を行った。図３に、廃棄物処分場内水を処理対象としたときの懸濁物質の凝集・沈澱処理効果を示す。図３から明らかなように、上水汚泥からの回収凝集剤を用いる場合、回収凝集剤２ｍＬ／ＬでＣＯＤが１０．６％、回収凝集剤１０ｍＬ／ＬでＴ−Ｎが１５．１％、回収凝集剤０．５ｍＬ／ＬでＴ−Ｐが５４．１％の最大除去率を示し、Ｔ−ＮおよびＴ−Ｐは硫酸バンドの最大除去率を上回った。回収凝集剤中に存在するＣＯＤやＴ−Ｎ、Ｔ−Ｐをも考慮した実質的な最大除去率は、それぞれ２８．２％、２１．５％、９６．５％と硫酸バンドの最大除去率をさらに上回っており、回収凝集剤に含まれている有機物質等の作用も加わって除去効果が増したものと考えられる。わけても、Ｔ−Ｐの除去効果が顕著である。 The coagulation / sedimentation effect of suspended solids in waste disposal site water and sewage treatment plant inflow water was investigated using the flocculant recovered from the water sludge. At that time, a comparison was made with a sulfate band and PAC. FIG. 3 shows the effect of flocculation / precipitation treatment of suspended substances when the water in the waste disposal site is treated. As is clear from FIG. 3, when using the recovered flocculant from the water sludge, the recovered flocculant is 2 mL / L, the COD is 10.6%, the recovered flocculant is 10 mL / L, and TN is 15.1%. The recovered flocculant showed a maximum removal rate of 54.1% at 0.5 mL / L, and TN and TP exceeded the maximum removal rate of the sulfate band. Considering the COD, TN, and TP present in the recovered flocculant, the practical maximum removal rates were 28.2%, 21.5%, and 96.5%, respectively. It is considered that the removal effect was increased by the action of organic substances contained in the recovered flocculant. Especially, the removal effect of TP is remarkable.

次に、下水処理場流入水を処理対象としたときの、懸濁物質の凝集・沈澱処理効果を調べた。その結果を図４に示す。また、懸濁物質の最大除去率を表１に示す。 Next, we investigated the effect of flocculation / precipitation treatment of suspended solids when treating the inflow water from the sewage treatment plant. The result is shown in FIG. Table 1 shows the maximum removal rate of suspended solids.

上水汚泥からの回収凝集剤を用いる場合、回収凝集剤５ｍＬ／Ｌで最大除去率は、ＣＯＤが６６．８％、Ｔ−Ｎが２９．９％、Ｔ−Ｐが９８．９％であり、硫酸バンド及びＰＡＣのそれを上回った。廃棄物処分場内水を処理対象とする場合に比し、ＳＳや有機物、栄養塩類を多く含む下水処理場流入水の場合、回収凝集剤中の有機物質等の作用がより大きく現れた。 When the recovered flocculant from the water sludge is used, the maximum removal rate at 5 mL / L of the recovered flocculant is 66.8% for COD, 29.9% for TN, and 98.9% for TP. , Surpassing that of sulfate band and PAC. Compared with the case where the water in the waste disposal site is treated, in the case of sewage treatment plant inflow water containing a large amount of SS, organic matter, and nutrient salts, the action of organic substances in the recovered flocculant appeared more greatly.

水道法水質管理目標設定農薬および使用されている農薬を含めた農薬類１１２種類と農薬分解物５種類の計１１７種類について、上水汚泥からの回収凝集剤による除去効果ならびに硫酸バンド及びＰＡＣによる除去効果を調べた。 Water supply method water quality management target setting pesticides and 112 types of pesticides including pesticides used and 5 types of pesticide degradation products, total 117 types, removal effect by recovered flocculant from water sludge and removal by sulfate band and PAC The effect was investigated.

十分な除去率が得られると考えられる、回収凝集剤量：２ｍＬ／Ｌ、硫酸バンド量：５０ｍｇ／Ｌ、ＰＡＣ量：５０ｍｇ／Ｌのときの農薬の種類別および農薬分解物の除去効果を、図５乃至図１１に示す。有機塩素系農薬１２種類の除去率は１３．１％〜１００％で、ｏ，ｐ’−ＤＤＤ：８９．３％〜９０．４％、ｐ，ｐ’−ＤＤＥ：９４．２％〜１００％、エンドリン：５２．９％〜５５．７％、アルドリン：１００％、ディルドリン：７２．４％〜７９．３％、ヘプタクロル：８４．６％〜１００％、およびヘプタクロルオキシド：６６．６％〜６８．８％の７種類が除去率５０％以上と、比較的除去されやすい。 It is considered that a sufficient removal rate can be obtained, the amount of recovered flocculant: 2 mL / L, the amount of sulfuric acid band: 50 mg / L, the amount of PAC: 50 mg / L As shown in FIGS. The removal rate of 12 types of organochlorine pesticides is 13.1% to 100%, o, p′-DDD: 89.3% to 90.4%, p, p′-DDE: 94.2% to 100% Endrin: 52.9% to 55.7%, Aldrin: 100%, Dildoline: 72.4% to 79.3%, Heptachlor: 84.6% to 100%, and Heptachlor Oxide: 66.6% to 68 Seven types of .8% are relatively easily removed with a removal rate of 50% or more.

有機燐系農薬２１種類の除去率は１０．８％〜１００％であった。除去率が高かったのは、ＥＰＮ：６８．３％〜６９．２％、クロルピリホス：６９．１％〜７１．３％およびプロチオホス：８４．８％〜８６．１％であった。また、カルバメート系農薬９種類の除去率は、５．１％〜６７．７％であった。除去率が高かったのは、ピリブチカルブ：６５．９％〜６７．７％の１種類であった。
含窒素系農薬５７種類の除去率は０％〜１００％であった。除去率が高かったのは、クロルフェナピル：７１．３％〜７２．７％、シハロホップブチル：６１．３％〜６４．８％、ジフェノコナゾール：６９．６％〜１００％、トリフルラリン：８０．３％〜８４．２％、ビデルタノール：５１．２％〜５５．７％、ピリダベン：８５．８％〜８６．３％、ピリプロキシフェン：６６．４％〜６７．８％、ペンシクロン：８０．１％〜８５．０％、およびペントキサゾン：５８．５％〜５９．７％の９種類に過ぎず、これらの農薬は凝集・沈澱処理で除去され難い。 The removal rate of 21 types of organophosphorus pesticides was 10.8% to 100%. The removal rates were high in EPN: 68.3% to 69.2%, chlorpyrifos: 69.1% to 71.3%, and prothiophos: 84.8% to 86.1%. Moreover, the removal rates of nine types of carbamate pesticides were 5.1% to 67.7%. The removal rate was high for one type of pyributicalbu: 65.9% to 67.7%.
The removal rate of 57 types of nitrogen-containing pesticides was 0% to 100%. The removal rate was high: chlorfenapyr: 71.3% -72.7%, cihalohop butyl: 61.3% -64.8%, difenoconazole: 69.6% -100%, trifluralin: 80.3 % To 84.2%, Bideltaanol: 51.2% to 55.7%, Pyridaben: 85.8% to 86.3%, Pyriproxyfen: 66.4% to 67.8%, Penciclone: 80.1 There are only 9 types of% to 85.0% and pentoxazone: 58.5% to 59.7%, and these pesticides are hardly removed by agglomeration / precipitation treatment.

一方、ピレスロイド系農薬８種類の除去率は８８．４％〜１００％と、すべての農薬で高かった。その他の農薬５種類および農薬分解物５種類の除去率はそれぞれ５．５％〜１００％、０％〜１００％で、除去率が高かったのは、ハルフェンプロックス：８９．０％〜１００％、メトプレン：６４．３％〜１００％、およびクロルスルフロン分解物：１００％であった。 On the other hand, the removal rate of 8 types of pyrethroid pesticides was 88.4% to 100%, which was high for all pesticides. The removal rates of the other 5 types of pesticides and 5 types of pesticide degradation products were 5.5% to 100% and 0% to 100%, respectively. The removal rate was high: Halfenprox: 89.0% to 100% , Metoprene: 64.3% -100%, and chlorosulfuron degradation product: 100%.

上水汚泥からの回収凝集剤の除去率が硫酸バンドやＰＡＣよりも高かったのは、有機塩素系農薬では１２種類中９種類（０％〜１７．７％高い）、有機燐系農薬では２１種類中１３種類（０．８％〜７８．１％高い）、カルバメート系農薬では９種類中９種類（１．３％〜２１．５％高い）含窒素系農薬では５７種類中４５種類（０％〜６７．０％高い）、ピレスロイド系農薬では８種類中２種類（０％〜１０．８％高い）、その他の農薬では５種類中５種類（０％〜３５．７％高い）、農薬分解物では５種類中４種類（０．２％〜４１．９％高い）と、ＣＯＤやＴ−Ｎ、Ｔ−Ｐと同様に多くの農薬類等で除去効果が硫酸バンドやＰＡＣを上回った。 The removal rate of recovered flocculant from clean water sludge was higher than that of sulfuric acid bands and PACs, 9 of 12 types of organochlorine pesticides (0% to 17.7% higher) and 21 of organophosphorus pesticides. 13 of the types (0.8% to 78.1% higher), 9 of the 9 carbamate pesticides (1.3% to 21.5% higher), 45 of 57 of the nitrogen-containing pesticides (0 % To 67.0% higher), 2 of 8 pyrethroid pesticides (0% to 10.8% higher), 5 of 5 other pesticides (0% to 35.7% higher), pesticides Among the degradation products, 4 of the 5 types (0.2% to 41.9% higher) and many pesticides as well as COD, TN, and TP have a higher removal effect than sulfate bands and PAC. .

上水汚泥に硫酸等を加えて撹拌し、ｐＨ：３．０〜４．０として凝集剤を濾過・回収する場合、汚泥分離性が悪くなりまた、濾過機を傷める可能性がある。そこで、実際には、浄水処理での汚泥脱水前にｐＨ調整槽を設け、ｐＨ：３．０〜４．０の上澄み液（回収凝集剤）抽出→中和（ｐＨ：７．０へ）→汚泥脱水を行う。その場合の汚泥分離性を調べた。 When sulfuric acid or the like is added to the water sludge and stirred, and the flocculant is filtered and collected at a pH of 3.0 to 4.0, the sludge separation property may deteriorate and the filter may be damaged. Therefore, in actuality, a pH adjustment tank is provided before the sludge dewatering in the water purification treatment, and the supernatant (recovered flocculant) is extracted from pH: 3.0 to 4.0 → neutralized (to pH: 7.0) → Perform sludge dewatering. The sludge separation property in that case was examined.

酸性上澄み液（ｐＨ：３．０〜４．０の回収凝集剤）を３０ｍＬ〜６２ｍＬ取り除き、残部をｐＨ：７．０に中和した後の汚泥の沈降速度および濾過速度を、図１２に示す。沈降速度は、元の上水汚泥や硫酸添加、撹拌による酸性状態のときよりもはるかに遅くなり、酸性上澄み液の取り除き量が少ないほど遅くなった。しかし、濾過速度はそれほど遅くはなく、硫酸添加、撹拌による酸性状態で濾過するよりも速くなった。フィルタープレス等の濾過脱水であれば問題ないと思われる。 FIG. 12 shows the sedimentation rate and filtration rate of sludge after removing 30 to 62 mL of acidic supernatant (recovered flocculant having a pH of 3.0 to 4.0) and neutralizing the remainder to pH 7.0. . The sedimentation rate was much slower than in the case of the acidic state due to the addition of original water sludge, sulfuric acid, and stirring, and became slower as the removal amount of the acidic supernatant was smaller. However, the filtration rate was not so slow, and was faster than filtration in an acidic state by addition of sulfuric acid and stirring. It seems that there is no problem if it is filtered and dewatered by a filter press or the like.

ｐＨ調整槽において、上水汚泥分散液に硫酸を加えて酸性とし凝集剤を回収する場合、汚濁成分や栄養塩類等も同時に上水汚泥から分離し、凝集剤回収後の残部を中和しても沈降分離できない部分が生じて、高濃度の汚濁成分や栄養塩類等を含む汚泥脱水廃液を出しかねない。そこで、上水汚泥１０ｇ（湿）を精製水で１００ｍＬとし（固形分約３．１％）、凝集剤液を３０ｍＬ〜６２ｍＬ（限界量）回収した場合の中和後の汚泥脱水液の水質を調べた。 In the pH adjustment tank, when sulfuric acid is added to the water sludge dispersion to make it acidic and the flocculant is recovered, the pollutants and nutrients are also separated from the water sludge at the same time, and the remainder after the flocculant recovery is neutralized. However, there is a part that cannot be settled and separated, and a sludge dewatering waste liquid containing high-concentration pollutants and nutrients may be produced. Therefore, the water quality of the sludge dewatered liquid after neutralization when 10 g of water sludge (wet) is made up to 100 mL with purified water (solid content is about 3.1%) and 30 to 62 mL (limit amount) of the flocculant liquid is recovered. Examined.

ＣＯＤ、Ｔ−Ｎ、およびＴ−Ｐについて、上水汚泥を単に精製水で分散した場合との比較を、図１３に示す。固液分離限界である６２ｍＬおよび５０ｍＬの凝集剤液を回収除去した場合、上水汚泥を単に精製水で分散したときのＣＯＤが３．４倍および４．８倍、Ｔ−Ｐが２．６倍および２．８倍に上昇したが、Ｔ−Ｎはあまり変わらなかった。環境への負荷を少なくするために、できる限り凝集剤液を多く回収した方がよい。下水道処理区域にある浄水場では、下水道に排出しても問題ない濃度である。 FIG. 13 shows a comparison of COD, TN, and TP with the case where the purified water is simply dispersed with purified water. When the 62 mL and 50 mL flocculant liquids, which are solid-liquid separation limits, are recovered and removed, the COD when the water sludge is simply dispersed with purified water is 3.4 times and 4.8 times, and TP is 2.6. TN and 2.8 times increased, but TN did not change much. In order to reduce the burden on the environment, it is better to collect as much flocculant liquid as possible. At the water treatment plant in the sewerage treatment area, the concentration is sufficient even if it is discharged into the sewer.

本発明は、下水、食品系廃水等における懸濁物質の凝集・沈澱処理のほか、あらゆる廃水の凝集沈澱処理および浮上処理に用いることができる。また、農薬類等の化学物質の除去にも用いることができる。 INDUSTRIAL APPLICABILITY The present invention can be used for flocculation / precipitation treatment of all waste water in addition to flocculation / precipitation treatment of suspended substances in sewage, food wastewater, and the like. It can also be used to remove chemical substances such as agricultural chemicals.

上水汚泥（湿）の量を２ｇ、５ｇ、１０ｇの３水準をパラメータとして、１．８Ｎの硫酸で滴定したときの滴定硫酸量（ｍＬ）とｐＨの関係を示すグラフA graph showing the relationship between the titrated sulfuric acid amount (mL) and pH when titrated with 1.8N sulfuric acid with the amount of water sludge (wet) as a parameter of 3 levels of 2 g, 5 g and 10 g. 廃棄物処分場内水を対象として、上水汚泥からの回収凝集剤を用いて懸濁物質の凝集・沈澱処理を行ったときの、ＣＯＤ、Ｔ−Ｎ、Ｔ−Ｐの除去率とｐＨの関係を示すグラフRelationship between removal rate of COD, TN, TP and pH when flocculation / precipitation treatment of suspended solids is performed using waste flocculant collected from waste water sludge for waste disposal site water Graph showing 廃棄物処分場内水を対象として、上水汚泥からの回収凝集剤を用いて懸濁物質の凝集・沈澱処理を行ったときの、ＣＯＤ、Ｔ−Ｎ、Ｔ−Ｐの除去率と凝集剤の量との関係を、硫酸バンドと対比して示すグラフCOD, TN, TP removal rate and flocculant removal rate when the suspended solids are agglomerated / precipitated by using the flocculant recovered from the wastewater sludge for waste disposal site water Graph showing the relationship with the amount of sulfuric acid in comparison with the sulfate band 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、ＣＯＤ、Ｔ−Ｎ、Ｔ−Ｐの除去率と凝集剤の量との関係を、硫酸バンド及びＰＡＣと対比して示すグラフCOD, TN, and TP removal rates when flocculation / precipitation treatment of suspended solids is performed using flocculating agent collected from sewage sludge and pH of 6 for sewage treatment plant inflow water Showing the relationship between the amount of flocculating agent and the amount of flocculant compared with sulfate band and PAC 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、有機塩素系農薬類の除去効果を示すグラフGraph showing the removal effect of organochlorine pesticides when flocculation / precipitation treatment of suspended solids is performed at a pH of 6 using a flocculant collected from sewage sludge for sewage treatment plant inflow water 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、有機燐系農薬類の除去効果を示すグラフGraph showing the removal effect of organophosphorus pesticides when flocculation / precipitation treatment of suspended solids is performed at a pH of 6 using a flocculant recovered from sewage sludge for sewage treatment plant inflow water 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、カルバメート系農薬類の除去効果を示すグラフGraph showing the removal effect of carbamate pesticides when flocculation / precipitation treatment of suspended solids is performed at a pH of 6 using the recovered flocculant from sewage treatment plant inflow water 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、含窒素系農薬類の除去効果を示すグラフGraph showing the removal effect of nitrogen-containing pesticides when flocculation / precipitation treatment of suspended solids is performed at a pH of 6 using the recovered flocculant from the sewage treatment plant inflow water 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、ピレスロイド系農薬類の除去効果を示すグラフA graph showing the removal effect of pyrethroid pesticides when flocculation / precipitation treatment of suspended solids is performed at a pH of 6 using a flocculant collected from sewage sludge for inflow water from a sewage treatment plant 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、その他の農薬類の除去効果を示すグラフA graph showing the removal effect of other pesticides when flocculating and precipitating the suspended solids at a pH of 6 using the recovered flocculant from the sewage treatment plant inflow water. 下水処理場流入水を対象として、上水汚泥からの回収凝集剤を用い、ｐＨを６として懸濁物質の凝集・沈澱処理を行ったときの、農薬分解物の除去効果を示すグラフGraph showing the removal effect of agricultural chemical degradation products when flocculation / precipitation treatment of suspended solids is carried out at a pH of 6 using flocculating agent collected from sewage sludge for sewage treatment plant inflow water 上水汚泥から凝集剤を回収するプロセスにおいて硫酸上澄み液（回収凝集剤）を抽出し、ｐＨ：７．０に中和後汚泥脱水を行うときの汚泥分離性（汚泥沈降速度および濾過速度）を示すグラフIn the process of recovering the flocculant from the water sludge, the sulfuric acid supernatant (recovered flocculant) is extracted, and the sludge separation (sludge sedimentation rate and filtration rate) when sludge dewatering is performed after neutralization to pH 7.0. Graph showing 上水汚泥から凝集剤を回収するプロセスにおいて硫酸上澄み液（回収凝集剤）を抽出し、ｐＨ：７．０に中和後の汚泥脱水液の水質を示すグラフGraph showing the water quality of sludge dewatered liquid after extraction of sulfuric acid supernatant (recovered flocculant) in the process of recovering flocculant from water sludge and neutralization to pH: 7.0

Claims

原水中の懸濁物質を凝集・沈澱処理して清澄な上水を得る凝集・沈澱処理プロセスから発生する汚泥に硫酸等による酸処理を施して得られる回収凝集剤を用いて、下水、食品系廃水、廃棄物処分場内水等における懸濁物質の凝集・沈澱処理又は浮上処理をｐＨ：５以上の領域で行うことを特徴とする上水汚泥からの回収凝集剤による下水、食品系廃水等の凝集・沈澱処理方法。
Using the recovered flocculant obtained by subjecting sludge generated from the flocculation / precipitation treatment process to acid treatment with sulfuric acid, etc. Wastewater, flocculation / precipitation treatment of suspended solids in waste disposal site water, etc. is performed in a pH: 5 or higher area, such as sewage by recovered flocculant, food wastewater, etc. Aggregation / precipitation method.