JPH0321392A - Coagulant adding method and apparatus - Google Patents
Coagulant adding method and apparatusInfo
- Publication number
- JPH0321392A JPH0321392A JP15630189A JP15630189A JPH0321392A JP H0321392 A JPH0321392 A JP H0321392A JP 15630189 A JP15630189 A JP 15630189A JP 15630189 A JP15630189 A JP 15630189A JP H0321392 A JPH0321392 A JP H0321392A
- Authority
- JP
- Japan
- Prior art keywords
- wastewater
- inorganic flocculant
- flocculant
- amount
- inorganic
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 26
- 239000000701 coagulant Substances 0.000 title abstract description 12
- 239000002351 wastewater Substances 0.000 claims abstract description 63
- 239000010800 human waste Substances 0.000 claims description 26
- 238000011282 treatment Methods 0.000 abstract description 23
- 238000002156 mixing Methods 0.000 abstract description 17
- 238000005345 coagulation Methods 0.000 abstract description 10
- 230000015271 coagulation Effects 0.000 abstract description 10
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 abstract description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 abstract description 3
- 229910021578 Iron(III) chloride Inorganic materials 0.000 abstract description 2
- 244000144992 flock Species 0.000 abstract description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 abstract description 2
- 239000010865 sewage Substances 0.000 abstract 3
- 238000005096 rolling process Methods 0.000 abstract 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 39
- 238000005189 flocculation Methods 0.000 description 19
- 230000016615 flocculation Effects 0.000 description 18
- 230000007246 mechanism Effects 0.000 description 11
- 239000003002 pH adjusting agent Substances 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 11
- 239000008394 flocculating agent Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000007788 liquid Substances 0.000 description 9
- 239000010802 sludge Substances 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 5
- 230000002378 acidificating effect Effects 0.000 description 5
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- MMDJDBSEMBIJBB-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] MMDJDBSEMBIJBB-UHFFFAOYSA-N 0.000 description 4
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 4
- 230000003139 buffering effect Effects 0.000 description 4
- 230000003311 flocculating effect Effects 0.000 description 4
- 239000010812 mixed waste Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- JVMRPSJZNHXORP-UHFFFAOYSA-N ON=O.ON=O.ON=O.N Chemical compound ON=O.ON=O.ON=O.N JVMRPSJZNHXORP-UHFFFAOYSA-N 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 240000001548 Camellia japonica Species 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 125000000129 anionic group Chemical group 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 235000018597 common camellia Nutrition 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005188 flotation Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000012263 liquid product Substances 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 1
- 229920006318 anionic polymer Polymers 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- STZCRXQWRGQSJD-GEEYTBSJSA-M methyl orange Chemical compound [Na+].C1=CC(N(C)C)=CC=C1\N=N\C1=CC=C(S([O-])(=O)=O)C=C1 STZCRXQWRGQSJD-GEEYTBSJSA-M 0.000 description 1
- 229940012189 methyl orange Drugs 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 125000001477 organic nitrogen group Chemical group 0.000 description 1
- 238000001139 pH measurement Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000009287 sand filtration Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 229920001897 terpolymer Polymers 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 235000020681 well water Nutrition 0.000 description 1
- 239000002349 well water Substances 0.000 description 1
Landscapes
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
Description
この発明は、し尿系の廃水に凝集剤を添加してその廃水
に含まれている浮遊物を凝集沈殿、凝集ｄ上、凝集濾過
等により凝集処理する方法に関し、さらに詳しくは無機
凝集剤のし尿廃水への添加量を適切に制御できる凝集剤
添加方法に関するものである。
この発明はまた、上記した凝集剤の添加方法を実施する
ために使川する凝集剤添加装置に関するものである。The present invention relates to a method of adding a flocculant to human waste wastewater and flocculating the suspended matter contained in the wastewater by coagulation sedimentation, flocculation, coagulation filtration, etc. The present invention relates to a method for adding a flocculant that allows appropriate control of the amount added to wastewater. The present invention also relates to a flocculant addition device used to carry out the above-described flocculant addition method.
一般に、凝集沈殿、凝集加圧浮上、凝集濾過等の凝集処
理に際しては、披処狸水のｐＨ調整と無機凝集剤の添加
と高分了凝果剤の添加が行われている。
例えば、従来の廃水処理における連続式凝集処理装置は
第５図に示したように、ｐＨ３１および急速攪け機を備
えた混和槽と、緩速攪ノ↑機を備えた凝集槽とからなっ
ている。混和槽には、無機凝集剤を定量供給する定量ポ
ンプが設けられ、凝集漕にはノニオン系、アニオン系等
の高分子凝集剤を凝集槽に定量供給する定量ボンブが設
けられている。これらの無機凝集剤と高分子凝集剤は、
それぞれ被処理水の設計流Ｅｌ（平均流ｆｆｉ）にあわ
せて注入量が定められ、定量ボンブによって定量注入さ
れる。またｐＨ調整剤は、ｐＨ計からの測定信号によっ
てその供給量が制御される定量ポンプを介して混和槽に
供給され、被処理水のｐＨが所定の値に調整される。
かような凝集処理装置によれば、廃水は先ず混和槽で急
速に攪袢されながら無機凝集剤が定量添加され、同時に
無機凝集剤の最適ｐＨ値になるようにｐＨ調整剤が添加
される。かくして混和槽内の廃水には微細な凝集フロッ
クが形威される。この廃水は次いで凝集椿へ送られ、こ
こでさらに高分子凝集剤が定量添加されるとともに緩速
攪社され、微細な凝集フロックは大きな凝集フロックに
成長する。凝集フロックが形成された廃水は、必要に応
じてさらに沈殿槽、浮上分離槽または濃縮スクリーン等
へ［１，給され、凝集フロックが分離される。Generally, during flocculation treatments such as flocculation-sedimentation, flocculation-pressure flotation, and flocculation filtration, the pH of the water is adjusted, an inorganic flocculant is added, and a high-resolution flocculant is added. For example, a conventional continuous flocculation treatment device for wastewater treatment consists of a mixing tank with a pH of 31 and a rapid stirrer, and a flocculation tank equipped with a slow stirrer, as shown in Figure 5. There is. The mixing tank is equipped with a metering pump that supplies a fixed amount of an inorganic flocculant, and the flocculating tank is equipped with a metering bomb that supplies a fixed amount of a nonionic, anionic, or other polymer flocculant to the flocculating tank. These inorganic flocculants and polymer flocculants are
The injection amount is determined according to the design flow El (average flow ffi) of the water to be treated, and a fixed amount is injected using a metering bomb. Further, the pH adjuster is supplied to the mixing tank via a metering pump whose supply amount is controlled by a measurement signal from a pH meter, and the pH of the water to be treated is adjusted to a predetermined value. According to such a flocculation treatment device, wastewater is first rapidly stirred in a mixing tank while an inorganic flocculant is added in a fixed amount, and at the same time, a pH adjuster is added to the wastewater so as to reach the optimum pH value of the inorganic flocculant. In this way, fine flocs form in the wastewater in the mixing tank. This wastewater is then sent to the flocculation chamber, where a polymer flocculant is further added in a fixed amount and slowly stirred, so that the fine flocs grow into large flocs. The wastewater in which the flocs have been formed is further fed to a settling tank, a flotation tank, a concentration screen, etc., as required, and the flocs are separated.
ところが、この種の廃水処理施設では、一般に被処理水
の水量変動に加えて、濾過機等の付属施設に使用された
洗浄水等の雑用水の一時的な流入があり、混和槽や凝集
槽に流入する被処理水の流量変動は非常に大きく、無機
凝集剤添加量および高分子凝集剤添加量の過不足が生じ
る。この添加量が不足すると処理水質に悪影響を与える
ことになる。
これに対して、無機凝集剤添加量および高分子凝集剤添
加量をそれぞれ被処理水の設ｎ１最大流量にあわせて定
量注入する場合には、添加量が過剰となることが多い。
さらに、無機凝集剤は酸性であるため、添加量が多い場
合にはその被処理水は最適ｐＨ値よりも酸性側となって
しまうため、ｐＨ調整剤（アルカリ）の泪費量が多くな
ってしまう。
上記のごとき問題点を解決する方法としては、混和槽に
流入する被処理水量を測定し、その被処理水量に応じて
凝集剤の添加量を制御することが考えられる。しかしな
がら、被処理水の変動は水量だけでなく水質の変動もあ
るため、やはり適確に制御することは難しい。すなわち
、凝集剤の添加量はＩｌｌに彼処理水の浮遊物（Ｓ Ｓ
）濃度に比例するものではないから、ジャーテストによ
らなければ水質の変動を適確に把握することは不可能で
ある。
従って、従来から慣用されている実装置においては凝集
剤添加量を決める適切な指標がなく、依然として上記の
問題が未解決であった。However, in this type of wastewater treatment facility, in addition to fluctuations in the amount of water to be treated, there is also a temporary inflow of miscellaneous water such as washing water used in attached facilities such as filters, and mixing tanks and coagulation tanks Fluctuations in the flow rate of the water to be treated flowing into the system are extremely large, resulting in excess or deficiency in the amount of inorganic flocculant and polymer flocculant added. If the amount added is insufficient, the quality of the treated water will be adversely affected. On the other hand, when the amount of inorganic flocculant and the amount of polymer flocculant added are fixedly injected in accordance with the set n1 maximum flow rate of the water to be treated, the amounts added often become excessive. Furthermore, since inorganic flocculants are acidic, if a large amount is added, the water to be treated will be on the acidic side than the optimum pH value, resulting in an increase in the amount of pH adjuster (alkali) used. Put it away. A conceivable method for solving the above problems is to measure the amount of water to be treated flowing into the mixing tank and to control the amount of flocculant added in accordance with the amount of water to be treated. However, since fluctuations in the water to be treated include not only fluctuations in water quantity but also fluctuations in water quality, it is still difficult to control accurately. In other words, the amount of flocculant added is determined by the amount of suspended matter (SS) in the treated water.
) Since it is not proportional to concentration, it is impossible to accurately understand changes in water quality without using a jar test. Therefore, in the actual equipment that has been conventionally used, there is no appropriate index for determining the amount of coagulant added, and the above problem remains unsolved.
一般に無機凝ｍ ｉ’ｌｌＪの共通有効ｐＨ域は、後掲
の第１表に示すように約４．５〜８．０であり、さらに
これらの無機凝集剤はすべて強酸性である。
また、活性ｌク泥法等の生物処ＩＩを施された廃水は、
生物処理に流入するときに多少ｐＨの変動があっても、
活性汚泥の緩衝作川によりｐＨ約７〜８を示す。
この点に着１」シて、本発明者らは上記の問題を解決す
べく種々険討した結果、生物処理を施されたし尿廃水が
特定の範囲のアルカリ度を有する場合には、アルカリ分
による一種の緩衝作用により、この廃水に特にｐＨ調整
剤を添加せずとも、無機凝集剤のみを添加して無機凝集
剤の有効ｐＨ範囲内の酸性側となるように廃水のｐＨ［
を調整すれば、適切な無機凝集剤の添加量が得られるこ
とを見出し、この発明を完成させたものである。
すなわちこの発明による凝果剤の添加方〆大は、生物処
理が施されかつアルカリ度３０００〜１２０００ｍｇ
／ Ｉを有するし尿廃水に凝集剤を添加するに際して、
し尿廃水のｐＨｌｉｆ（を無機凝果剤の添加のみによっ
て調整するとともに、該廃水のｐＨ値が４．５〜６，５
の範囲となるように無機凝集剤の添加量を制御すること
を特徴とするものである。
さらにこの発明の凝集剤添加装置は、上記の方法を効果
的に実施するために考えられたものであって、生物処理
が施されかつアルカリ度３０００〜＋２０００ ＋＋ｌ
ｇ／Ｄを有するし尿廃水の流路に設けられ該廃水のｐＨ
をｉｌＦＪ定するｐＨセンサと、該流路に無機凝集剤を
添加供給する無機凝集剤供給装置と、該ｐＨセンサによ
るｐＨ測定値をｐＨ４．５〜６．５の範囲内の設定目標
値と比較してその偏差を最少にする制御信号を該供給装
置へ出力し該供給装置から該流路への無機凝集剤供給量
を制御する制御手段とからなることを特徴とするもので
ある。
この発明で使用．される無機凝集剤としては、例えば硫
酸アルミニウム（硫酸バンド）、ポリ塩化アルミニウム
（ＰＡＣ） 、塩化アルミニウム、塩化第二鉄、ポリ硫
酸第三鉄、硫酸第二鉄、硫酸第一鉄等が挙げられる。
硫酸アルミニウムは、固体●粉状のものはＡ １ ２
０ ３として１６％含有するもの、液状のものはＡ！２
０３として８％含有するものが市販されている。ポリ塩
化アルミニウムは、化学式ＡＩ （ＯＨ） ◆Ｃｌ
で表され、例えｎ 清 ３ｎ一四
ばＡｌ （ＯＨ） ・Ｃ ｌ ｅ等 が あ り５
９
Ａ！２０３として１０〜１１％含有する液体製品が市販
されている。塩化アルミニウムは、有効成分が９％（Ａ
ｌ２０３）の液体製品が最も多く市販されている。廖化
第二鉄は・通堂４０°ボーメ（約３８％Ｆ ｅ Ｃ １
３ ）の液体として市販されている。ポリ硫酸第三鉄
は、
［Ｆ ｅ （ＯＨ） （Ｓ ０４ ） ３−ｎ／
２ ］ ｌＩで示ｎ
される水溶液である。
従って無機凝集剤は、通常水溶液の状態で使用されるこ
とが多く、固体の状態で使用されることはまれである。
しかしながら本明細書においては、無機凝集剤という用
語は、水溶ｌｃｋの状態だけでなく固体の状態の無機凝
集剤も含まれるものとして使用する。またこの発明にお
いては、これら無機凝集剤の１種をｔ１１独で使用する
こともできるが、２種以上を混合して使用することもで
きる。
上記した無機凝集剤の共通有効ｐＨ域は第１表に示すよ
うにおおよそ４．５〜８．０であり、またこれらの無機
凝集剤はいずれも強酸性である。
第１表： 無機凝集剤の有効ｐＨ域
無機凝集剤 ｐＨ域
硫酸アルミニウム（硫酸バンド）４．５〜８．０ボリ廖
化アルミニウム（ Ｐ Ａ Ｃ ） ４．５〜８．０
壇化アルミニウム ４．５〜８．０堪化
第二鉄 ４．５〜１１．０ポリ硫
酸第二鉄 ４．５〜１１．０本明細書
におけるアルカリ度という用語は、廃水中に含まれてい
るアルカリ分を炭酸カルシウム（ Ｃ ａ Ｃ Ｏ ａ
）に換算して１ｇ中のｍｇｍで示したものである。こ
のアルカリ度は別名「Ｍアルカリ度（メチルオレンジア
ルカリ度）」または「全アルカリ度」とも称されるもの
である。
この発明において無機凝集剤が添加される廃水は、生物
処理が施されかつアルカリ度が３０００〜１２０００
＋ｎｇ／Ｄ ，好ましくは４０００〜８０００ｍｇ ／
Ｄ ，さらに好ましくは５０００〜７０００ｍｇ／Ｎ
のし尿廃水である。
生物処理としては、微生物により廃水を処理するもので
あればいかなる方法でもよく、例えば浮遊式（活性汚泥
法）、固定床式、微生物を付着または固定した担体を流
動させて処理する方式などが挙げられる。
また、アルカリ度が３０００〜１２０００ ｍｇ／ ｆ
ｌの範囲内にないと、アルカリ分による緩衝作用が十分
に期待できず、無機凝集剤のみの添加によって廃水のｐ
Ｈを所定の範囲に調整することが困難となる。
また特にし尿廃水は、生物処裡を施す前の状態でアルカ
リ度５０００〜７０００＋ｗｇ／Ｎを有し、硝化脱窒の
生物処理を行ってもアルカリ度は僅かしか変化しないの
で、この発明における対象廃水とすることができる。
無機凝集剤の添加に際しては、上記のごときし尿廃水の
ｐＨ値を無機凝集剤の添加のみによって調整し、この廃
水のｐ Ｈ値が４．５〜６．５の範囲、好ましくは５〜
６．５の範囲、さらに好ましくは５．５〜６の範囲とな
るように無機凝集剤の添加量を制御する。すなわち別の
表現をとれば、無機凝集剤を添加することによってこの
廃水のｐｎが上記所定値となるように、無機凝集剤の添
加量を制御する。さらに換言すれば、無機凝集剤を添加
してこの廃水のｐＨが上記所定値になることを条件に、
無機凝集剤の添加量を制御する。Generally, the common effective pH range of inorganic flocculants is about 4.5 to 8.0, as shown in Table 1 below, and all of these inorganic flocculants are strongly acidic. In addition, wastewater that has been subjected to biological treatment II such as the activated lactic mud method,
Even if there are slight pH fluctuations when flowing into biological treatment,
It exhibits a pH of about 7 to 8 due to the buffering of activated sludge. Based on this point, the present inventors conducted various investigations to solve the above problem, and found that if the biologically treated human waste wastewater has an alkalinity within a specific range, the alkalinity Due to a kind of buffering effect, the pH of the wastewater [[
The present invention was completed based on the discovery that an appropriate amount of inorganic flocculant can be obtained by adjusting the amount of the inorganic flocculant. In other words, the maximum amount of addition of the flocculant according to the present invention is that it is biologically treated and has an alkalinity of 3,000 to 12,000 mg.
/ When adding a flocculant to human waste wastewater having
The pH of human waste wastewater is adjusted only by the addition of an inorganic flocculant, and the pH value of the wastewater is adjusted from 4.5 to 6.5.
It is characterized by controlling the amount of the inorganic flocculant added so that it falls within the range of . Furthermore, the flocculant addition device of the present invention was devised to effectively implement the above method, and is biologically treated and has an alkalinity of 3000 to +2000 ++l.
g/D in the flow path of human waste wastewater, and the pH of the wastewater is
A pH sensor that determines ilFJ, an inorganic flocculant supply device that adds and supplies an inorganic flocculant to the flow path, and a comparison of the pH measurement value by the pH sensor with a set target value within the range of pH 4.5 to 6.5. and a control means for outputting a control signal for minimizing the deviation to the supply device and controlling the amount of inorganic flocculant supplied from the supply device to the flow path. Used in this invention. Examples of inorganic coagulants used include aluminum sulfate (sulfuric acid band), polyaluminum chloride (PAC), aluminum chloride, ferric chloride, polyferric sulfate, ferric sulfate, ferrous sulfate, etc. . Aluminum sulfate is solid ● Powder is A 1 2
Those containing 16% as 03 and liquid are A! 2
03 containing 8% is commercially available. Polyaluminum chloride has the chemical formula AI (OH) ◆Cl
For example, there are Al (OH) ・Cle etc.5
9 A! Liquid products containing 10-11% as 203 are commercially available. Aluminum chloride contains 9% active ingredient (A
1203) liquid products are the most commercially available. Liaohua Second Railway - Tongtang 40° Baume (approximately 38% F e C 1
3) It is commercially available as a liquid. Polyferric sulfate is [Fe (OH) (S 04 ) 3-n/
2 ] It is an aqueous solution represented by lI. Therefore, inorganic flocculants are often used in the form of an aqueous solution, and rarely in the form of a solid. However, in this specification, the term inorganic flocculant is used to include not only the aqueous lck state but also the solid state of the inorganic flocculant. Further, in the present invention, one type of these inorganic flocculants can be used alone, but two or more types can also be used in combination. The common effective pH range of the above-mentioned inorganic flocculants is approximately 4.5 to 8.0 as shown in Table 1, and all of these inorganic flocculants are strongly acidic. Table 1: Effective pH range of inorganic flocculant Inorganic flocculant pH range Aluminum sulfate (sulfuric acid band) 4.5 to 8.0 Boric aluminum (P A C ) 4.5 to 8.0
Alkalinity 4.5-8.0 Ferric 4.5-11.0 Polyferric sulfate 4.5-11.0 The term alkalinity in this specification refers to the alkalinity contained in wastewater. Calcium carbonate (C a C O a
) and expressed in mgm per 1g. This alkalinity is also called "M alkalinity (methyl orange alkalinity)" or "total alkalinity." In this invention, the wastewater to which the inorganic flocculant is added has been subjected to biological treatment and has an alkalinity of 3000 to 12000.
+ng/D, preferably 4000-8000mg/
D, more preferably 5000 to 7000 mg/N
This is human waste wastewater. Biological treatment may be any method that treats wastewater using microorganisms, such as a floating method (activated sludge method), a fixed bed method, or a method in which a carrier to which microorganisms are attached or immobilized is made to flow. It will be done. In addition, the alkalinity is 3000 to 12000 mg/f
If it is not within the range of l, the buffering effect of the alkaline content cannot be expected sufficiently, and the pH of the wastewater will be lowered by adding only the inorganic flocculant.
It becomes difficult to adjust H within a predetermined range. In particular, human waste wastewater has an alkalinity of 5000 to 7000 + wg/N before being subjected to biological treatment, and the alkalinity changes only slightly even after biological treatment such as nitrification and denitrification. It can be done. When adding an inorganic flocculant, the pH value of the human waste wastewater as described above is adjusted only by adding the inorganic flocculant, and the pH value of this wastewater is in the range of 4.5 to 6.5, preferably 5 to 6.5.
The amount of the inorganic flocculant added is controlled to be in the range of 6.5, more preferably in the range of 5.5 to 6. In other words, the amount of the inorganic flocculant added is controlled so that the pn of the wastewater becomes the predetermined value. In other words, on the condition that the pH of this wastewater becomes the above-mentioned predetermined value by adding an inorganic flocculant,
Control the amount of inorganic flocculant added.
この発明によれば、生物処理が施されかつアルカリ度３
０００−１・２０００■／ｇを有するし尿廃水の場合に
、この廃水のｐＨｌａを４．５〜６．５の範囲になるよ
うに無機凝集剤を添加することによって、適切な無機凝
集剤の添加量がｎ然に得られることになる。また、流入
廃水の負荷（流量および／または水質）変動が生じても
ｐ Ｈ 制ＷＨＪを無機凝集剤により行っているので、
その廃水に応じた添加量となる。すなわち、水量が多く
なれば、当然所定のｐＨ値にするのに多くの無機凝集剤
が必要となり、水量が少なくなれば、所定のｐＨ値にす
るのに少ない無機凝集剤で済む。また、無機凝集剤は、
水中でイオンとして電離し、廃水中のアルカリ度成分と
反応して水酸化物がつくられ、これらが負帯電の粒子に
吸着され、正荷電により粒子の荷電を中和し、粒子を互
いにくっつけあわせてフロックをつくる。
この廃水のアルカリ度は廃水中の懸濁物質の濃度と比較
的相関関係があるので、彼処押水の水質が悪化すれば、
無機凝集剤がそれだけ消費され、所定のｐＨｆＩにする
のに多くの無機凝集剤が必要となり、被処理水の水質が
よければ、所定のｐＨ値にするのに少ない無機凝集剤で
済む。
また、上記アルカリ度威分による一種の緩衝作用によっ
て特にｐＨ調整剤を使用せずとも、無機凝集剤の有効ｐ
Ｈ範囲内の酸性側となるように無機凝集剤を添加するこ
とにより、適切な無機凝集剤の添加量が得られるのであ
る。According to this invention, biologically treated and alkalinity 3
In the case of night soil wastewater having a pH value of 000-1/2000/g, an appropriate inorganic flocculant can be added by adding an inorganic flocculant so that the pH value of this wastewater falls within the range of 4.5 to 6.5. The amount can be obtained naturally. In addition, even if the load (flow rate and/or water quality) of inflowing wastewater fluctuates, pH control WHJ is performed using an inorganic coagulant.
The amount added depends on the wastewater. That is, if the amount of water is large, naturally more inorganic flocculant is required to achieve a predetermined pH value, and if the amount of water is smaller, less inorganic flocculant is required to achieve a predetermined pH value. In addition, inorganic flocculants are
It ionizes as ions in water and reacts with alkalinity components in wastewater to create hydroxides, which are adsorbed by negatively charged particles, neutralize the charges on the particles with positive charges, and cause the particles to stick together. to make a flock. The alkalinity of this wastewater is relatively correlated with the concentration of suspended solids in the wastewater, so if the water quality of the wastewater deteriorates,
The more inorganic flocculant is consumed, the more inorganic flocculant is required to achieve a predetermined pH fI, and if the quality of the water to be treated is good, less inorganic flocculant is needed to achieve a predetermined pH value. In addition, the effective pH of the inorganic flocculant can be improved without using any particular pH adjuster due to the kind of buffering effect caused by the alkalinity.
By adding the inorganic flocculant so that it is on the acidic side within the H range, an appropriate amount of inorganic flocculant can be obtained.
【実施Ｎｌ
この発明の添加装置の実施例を第３図のプロックダイヤ
グラムを参照して説明する。
ｐＨセンサｌはｐＨ［極とも称され、無機凝集剤を添加
するし尿廃水の流路に設置してこの廃水のｐＨを測定す
るものであり、ガラス電極と比較電極の組合わせからな
るものが最も多い。
制御手段２は、ｐＨセンサ１でｌ１＄１定されたｐＨ値
を設定目標値と比較して、その偏差を最小にする制御信
号を無機凝集剤供給装ｇｌ３へ出力しこの０（給装置３
からの無機凝集剤供給量を制御するためのものである。
この制御手段２は、機能的には、ｐＨセンサ１の例えば
ガラスｒｒ１ｔｆ！と比較電極により構成された電池の
起電力を測定して指示（記録）機構および比較部に７１
−１定信号を出力する受信要素（変換器）２ａと、ｌ１
？＋定信号を受けてｐＨ値を表示し必要により記録する
指示（記録）機構２ｂと、１１標のｐＨｌｉｆｆｆを比
較部に供給する設定機ｌ１ｉ％ ２ ｃと、測定信号と
設定機構からの信号とを比較しその偏差を調節機構に［
％給する比較部２ｄと、比較部からの偏差に基づいてそ
の偏差を最小にする制御信号を出力する調節機構２ｅと
から構威される。また、装置構成上は、ｐＨセンサ１と
受信要素（変換器）２ａと指示（記録）機ＥＬＬＳ ２
ｂとからなるｐＨ計４および設定機ｔＭ ２ ｃと比
較部２ｄと調節機構２Ｃとからなる調節器（コントロー
ラ）５により構成してもよく、あるいは、受信要素（変
換！）２ａと指示（記録）機構２ｂと設定機構２ｃと比
較部２ｄと調節機構２ｅとを１つの機器（コントローラ
やコンピュータ）にまとめて構成してもよく、種々の変
形が可能である。
いずれにしても、制御信号を出す調節動作は比例、積分
、微分のｌｊ独または組合せや２値動作等で行われる。
無機凝集剤供給装置３は、ｆｆｉｌ ＃手段２からの制
御信号を操作量に変えて無機凝集剤の供給量を直接制御
するものであって、具体的には定量ボンブ、調節弁また
は電磁弁等とそれらに付随する配青やタンク類等から摺
威される。また上記した定量ポンプ、調節弁または電磁
弁等はさらに、ポンプ本体あるいは弁本体等の本体部と
、制御信号に基づいてこの本体部を作動させる電気、空
気、浦圧式等の操作機構（駆動部）とから摺威されてい
る。
ｐ Ｈセンサ１や無機凝集剤供給装置３が設置される廃
水流路としては、具体的には配管あるいは槽のいずれで
もよい。配管に設置する場合には、無機凝集剤の添加位
置の下流側にｐＨセンサを設けなければならず、ぞの際
、無機凝集剤が廃水中に添加されてからその廃水のｐＨ
が測定されるまでの廃水の滞留時間は、３〜８分程度と
なるようにするのが好ましい。
第１図はこの発明の無機凝集剤添加装置を備えた連続式
凝集処理装置の一例を示すものである。この凝集処理装
置は、ｐＨ計１１と急速攪社機４１を備えた混和槽４０
、および緩速攪袢機５１を備えた凝集槽５０を有してお
り、さらに混和槽４０には、定量注入ボンブ３１とこれ
に付随する無機凝集剤タンク３２と供給κ管３３とから
構成される無機凝集剤供給装ａ！３０が設けられ、凝集
槽５０には高分子凝集剤を定量供給する定量ボンプ５２
と高分子凝集剤タンク５３が設けられている。ｐＨ１１
１はｐＨセンサ１０と変換器２１とからなり、ｐＨセン
サ１０はｐＨ電極１２と専用ケーブル１３とから＋Ｍ成
されている。無機凝集剤［％給量を制御する制御手段２
０は、変換器２１と調節器２２とからなっており、調節
器２２は第３図に図示した設定機構、比較部および調節
機構の機能が備えられている。また定量注入ボンプ３１
は、操作機祷（駆動部）３１ａとポンプ本体３１ｂとか
らなり、操作機構３１ａは、調節器２２からの制御信号
に基づいてポンプ本体３ｌｂのストローク数を変えるこ
とによって、無機凝集剤のｆｊＬ給量を制御することが
できる。
生物処理を施されかつアルカリ度３０００〜１２０００
■／ｇを有するし尿廃水は、先ず混和槽４０で急速（１
００〜１５０ｒｐｍ程度）に攪袢されるとともに、この
廃水のｐＨが４．５〜Ｂ．５、奸ましくは５〜Ｂ．５、
さらに好ましくは５．５〜６の範囲となるように無機凝
集剤供給装置３０から無機凝集剤が廃水中に添加される
。このときの無機凝集剤添加量は、ｐＨ計１１でのｐＨ
測定信号に越づいて制御手段２０から出力される制御信
号によって制御される。このようにして、ｐＨ調整剤を
使用せずとも無機凝集剤の添加のみで混和？ｆｌ４０内
の廃水のｐＨが調整され、かつ無機凝集剤の有効ｐＨ範
囲内での適切な・添加量が添加されることになり、その
結果廃水中には微細な凝集フロックが形成される。
混和ｔｆｆ４０での廃水の滞留時間は一般に３〜８分程
度とし、この滞留時間ののち凝集＃ｆ！Ｉ５０へ移送さ
れ、ここでさらに高分子凝集剤が定量添加されるととも
に緩速攪ｆｆ（１０〜ＢＯｒｐｍ ）され、微細な凝集
フロックは大きな凝集フロックに或長ずる。なお、凝集
槽５０で添加される高分子凝集剤としては、ｐＨ域が４
．５〜６，５で有効に作用するもの、例えばノニオン性
またはアニオン性三元共重合物等が好ましく使用できる
。
また、凝集槽５０での廃水の滞留晴間は一般に１５〜３
０分程度とする。
上記したような凝集処理によって凝集フロックを形威せ
しめたし尿廃水は、従来と同様に必要に応じて沈殿漕、
浮上分！槽、または濃縮スクリーン等に供給され、凝集
フロックを分離する。
すなわち、沈殿漕では凝集フロックを沈殿させて処理水
と分離する。
浮上分Ｎ槽においては、凝集槽からの凝集フロックを含
んだ廃水を加圧し、これにほぼ同圧の空気を供給して空
気を廃水中に溶解させた後、減圧して微細気泡を発生さ
せて凝集フロックに付着せしめ、凝集フロックを浮上さ
せる。かくして、凝集フロックを濃縮するとともに、処
ＰＰ水から分離する。
濃縮スクリーンにおいては、凝集フロックをスクリーン
等により除去し、処理水と濾過分離する。
第２図はこの発明の無機凝集剤添加装置における無機凝
集剤１ｊＩ−給装置の別な例を示すものであり、第ｌ図
と同じ構成要素については同じ参照番号を付すことによ
って説明を省略する。第１図と異なる構或は、第ｌ図の
定量注入ボンブ３１に代えて調節弁３５を用いた点であ
る。これに伴い調節器２２は、第３図における無機凝集
剤供給装置の操作機ＩＮの一部機能を備え、調節器２２
から調節井３５の開度が適切に制御できるように弁作動
空気２３が出力される。調節弁３５においては、弁作動
空気２３によりダイヤフラム等を介して弁の開度が調節
され、無機凝集剤の添加量が制御される。なお、第２図
の注入ボンプ３６を省略して、高低差によって無機凝集
剤タンク３２から調節弁３５へ無機凝集剤を移送するよ
うにしてもよい。また、：ｊ！４＠弁３５に代えて電磁
弁を使用し、オンオフ制御するようにしてもよい。
実験例
ＢＯＤやＣＯＤとともにし尿廃水中のアンモニアを除去
する、第４図のごとき標準脱窒素処理方式によるし尿施
設で、この発明の無機凝集剤添加法を実施した。
この施設における廃水処理は次のようにしてなされる。
各受入槽を経て佇留槽に一時受入れられたし尿と浄化槽
汚泥は、それぞれ前処理工程においてスクリーンにより
濾過され、希釈椿に流入する。ここでし尿と浄化槽汚泥
は混合されるとともに希釈水によって約１０倍以下に希
釈される。希釈された混合廃液は第１脱窒素椿（攪け槽
）を経て好気性酸化条件下に維持された硝化＃ｆ！（第
１ＩＩｌｌ気槽）に供給され、ここで混合廃液中の有機
性窒素とアンモニア性窒素が硝化されるとともにＢＯＤ
物質の除去が行われる。
硝化により生成した亜硝酸性窒素と硝酸性窒素を含む硝
化槽内の混合液の大部分は、第１脱窒素槽に循環（返送
）される。
この第１脱窒素槽は嫌気性還元条件下に維持されており
、希釈されたし尿と浄化槽汚泥の混合廃液、硝化槽より
循環された混合液、および沈殿槽から返送された返送汚
泥が混合されて滞留されている。そして、硝化槽で硝化
生成され第１脱窒素槽に循環された亜蛸酸性窒素と硝酸
性窒素は、この第１脱窒素槽内に流入したし尿と浄化槽
汚泥の混合廃液のＢＯＤ成分を有機炭素源として利用す
る通性嫌気性閑によって窒素ガスに還元され、脱窒素さ
れるとともにこのＢＯＤ成分も除去される。
次に、第１脱窒素漕と硝化槽を経た混合液は嫌気性還元
条件下に維持された第２脱窒素槽に導入され、先の第１
脱窒素槽で還元されなかった残りの亜硝酸性窒素と硝酸
性窒素が、窒素ガスに還元され脱窒素される。この場合
、第２脱窒素漕内に若干のメタノールが補助的に添加さ
れ、亜硝酸性窒素と硝酸性窒素の窒素ガスへの還元速度
が促進される。
第２脱窒素槽を経た脱窒混合液は次いで再曝気椿へ送ら
れ、ここで空気曝気が施されて残余のＢＯＤ成分が除去
されるとともに活性汚泥に付着したガスの脱気が行われ
る。そして、沈殿槽て処理水と活性汚泥とが沈陣分離さ
れ、処理水はさらに凝集分離工程へ導かれる。
凝集分離工程は、ｐＨｇｌと急速攪け機とを備えた混和
槽、緩速授け機を備えた凝集槽、および沈殿槽から構成
される。混和漕にはさらに、無機凝集剤をこの混和槽へ
定量供給する定量ボンブが設けられ、凝集槽には高分子
凝集剤を定Ｅｌ （ｊ’給する定量ポンプが設けられて
いる。この凝集分離工程で処理された処理水は、オゾン
酸化工程、砂濾過工程、活性炭処理工程および消毒工程
を経て放流される。
かかるし尿処理施設において、この実験例では、凝集分
離工程を第５図に示したようなｐＨ調整剤を添加してｐ
Ｈ調整する従来方式から、第１図に示したような無機凝
集剤の添加のみでｐＨ調整するこの発明の方式に改造し
て行った。
混和槽に添加する無機凝集剤としては硫酸バンドを使用
し、混和槽内の被処理水のｐＨ［が５，５となるように
無機凝集剤の添加量をｐＨ計で制御した。また凝集哨に
添加する高分子凝集剤としてはアニオン系高分子凝集剤
「アロンフロック」 （東亜合戊（株）製商品名）を使
用した。
なお、原水であるし尿のアルカリ度は５０００〜７００
０■／ｐであったにもかかわらず、井戸水で約１０倍希
釈された凝集分離工程の流入水のアルカリ度はほとんど
変わらず、約５０００ｍｇ／ρであった。
この実験例での薬剤使用量と凝集分離工程における流入
水質と処理水質とを第２表および第３表にまとめて示す
。また比較のために、第５図の従来方式（ｐＨ調整剤使
用）による桔果も第２・表および第３表に併せて示す。
第２表と第３表からわかるように、本発明方式によれば
、処理′水質を変えることなく苛性ソーダ（ｐＨ調整剤
）を処理水１ｍ３当り０．０４ｋｇの節約ができるだけ
でなく、無機凝集剤の使用量も処理水１２当り１０ｍｇ
程度節約できた。これは、し尿１００ｋｊ？／口の処理
施設では年間約３１０万１曹１（苛性ソーダ約２００万
１１、無機凝集剤約１１０万１ｌ１）の節減となる。
なお、上述した実施例はこの発明の好ましい実施態様を
説明するためのものであり、この発明はこれらの実施例
のみに限定されるものではない。例えば、上述の実施例
では、混和槽で無機凝集剤を添加攪拌する例を示したが
、この発明による攪拌操作はこうした例に限定されず、
配青中に無機凝集剤を添加して、配青中の流れによる攪
社、ポンプを通過させることにょる攪社等によって行う
こともできる。
また、上述の実施例では、凝集沈殿を連続式で行う例を
説明したが、回分式で行ってもよいことは勿論である′
。
さらに、上述の実施例では、車純にｐＨだけを検出して
無機凝集剤の添加を制御する例を説明したが、例えば凝
集処理工程に流入する披処理水の流量も検出して、流入
量が所定の流量より増加すれば無機凝集剤の添加速度を
速め、流入量が所定の流量より減少すれば無機凝集剤の
添加速度を遅くするなどのフィードフォワード等の制御
を併用することもできる。
【発明の効果】
上述したところからわかるようにこの発明によれば、し
尿廃水を凝集処理するに際して、し尿廃水のｐＨ値を無
機凝集剤のみを添加することによって調整し、かつその
ｐＨ値が所定の範囲となるようにその添加量を制御する
｛Ｒ成としたため、ｐＨ調整剤を特に使用せずとも効果
的な凝集処理を行うことができ、その分ｐＨ調整剤を節
減することができる。
さらにこの発明によれば、無機凝集剤自体の所要添加量
も減少できるため、上記ｐＨ調整剤の節減と相俟って、
経済的に有利でしかも効率のよいし尿廃水の凝集処理が
可能となる。[Embodiment Nl] An embodiment of the addition apparatus of the present invention will be described with reference to the block diagram of FIG. A pH sensor (also called a pH pole) is installed in the flow path of human waste wastewater to which an inorganic flocculant is added to measure the pH of this wastewater. many. The control means 2 compares the pH value determined by the pH sensor 1 with the set target value, outputs a control signal to minimize the deviation to the inorganic flocculant supply device gl3, and outputs a control signal to the inorganic flocculant supply device gl3.
This is to control the amount of inorganic flocculant supplied from the inorganic flocculant. This control means 2 is functionally controlled by, for example, the glass rr1tf! of the pH sensor 1. The electromotive force of the battery, which is composed of the
−1 receiving element (converter) 2a that outputs a constant signal, and l1
? + An instruction (recording) mechanism 2b that receives a constant signal, displays the pH value, and records it if necessary; a setting device l1i% 2c that supplies 11 pH liffs to the comparison section; and a measurement signal and a signal from the setting mechanism. Compare the difference and apply the deviation to the adjustment mechanism [
It consists of a comparator 2d that provides a percentage compensation, and an adjustment mechanism 2e that outputs a control signal that minimizes the deviation based on the deviation from the comparator. In addition, the device configuration includes a pH sensor 1, a receiving element (converter) 2a, and an indicating (recording) device ELLS 2.
It may be composed of a pH meter 4 consisting of a pH meter 4 and a setting device tM2c, a comparator 2d, and a regulator (controller) 5 consisting of a regulating mechanism 2C, or a receiving element (conversion!) 2a and an instruction (recording). ) The mechanism 2b, the setting mechanism 2c, the comparison section 2d, and the adjustment mechanism 2e may be combined into one device (controller or computer), and various modifications are possible. In any case, the adjustment operation for issuing the control signal is performed by proportional, integral, differential lj-independent or combination, binary operation, etc. The inorganic flocculant supply device 3 directly controls the supply amount of the inorganic flocculant by converting the control signal from the ffil # means 2 into a manipulated variable, and specifically controls the supply amount of the inorganic flocculant using a metering bomb, a control valve, a solenoid valve, etc. It is impressive from the blue color scheme and tanks that accompany them. The above-mentioned metering pump, control valve, solenoid valve, etc. further includes a main body such as a pump body or a valve body, and an electric, pneumatic, or pressure-type operating mechanism (drive unit) that operates the main body based on a control signal. ). Specifically, the wastewater channel in which the pH sensor 1 and the inorganic flocculant supply device 3 are installed may be either piping or a tank. When installed in a pipe, a pH sensor must be installed downstream of the addition point of the inorganic flocculant.
It is preferable that the residence time of the wastewater until it is measured is about 3 to 8 minutes. FIG. 1 shows an example of a continuous flocculation treatment apparatus equipped with an inorganic flocculant addition apparatus according to the present invention. This flocculation treatment device includes a mixing tank 40 equipped with a pH meter 11 and a rapid stirring machine 41.
, and a flocculating tank 50 equipped with a slow stirrer 51, and the mixing tank 40 further includes a metered injection bomb 31, an accompanying inorganic flocculant tank 32, and a supply κ pipe 33. Inorganic flocculant supply device a! 30 is provided, and the flocculation tank 50 is provided with a metering pump 52 for supplying a fixed amount of polymer flocculant.
and a polymer flocculant tank 53 are provided. pH11
1 consists of a pH sensor 10 and a converter 21, and the pH sensor 10 is made up of a pH electrode 12 and a dedicated cable 13. Inorganic flocculant [control means 2 for controlling the % supply amount
0 consists of a converter 21 and a regulator 22, and the regulator 22 is provided with the functions of a setting mechanism, a comparison section, and an adjustment mechanism shown in FIG. Also, quantitative injection pump 31
consists of an operating device (drive section) 31a and a pump main body 31b. The amount can be controlled. Biologically treated and alkalinity 3000-12000
■/g of human waste wastewater is first rapidly (1
00-150 rpm), and the pH of this wastewater is 4.5-B. 5, 5-B. 5,
More preferably, the inorganic flocculant is added to the wastewater from the inorganic flocculant supply device 30 so that the concentration is in the range of 5.5 to 6. The amount of inorganic flocculant added at this time is the pH measured by pH meter 11.
It is controlled by a control signal output from the control means 20 over the measurement signal. In this way, it is possible to mix just by adding an inorganic flocculant without using a pH adjuster? The pH of the wastewater in fl40 is adjusted, and an appropriate amount of inorganic flocculant within the effective pH range is added, resulting in the formation of fine flocs in the wastewater. The residence time of wastewater in the mixing TFF40 is generally about 3 to 8 minutes, and after this residence time, flocculation #f! The flocs are transferred to I50, where a polymer flocculant is further added in a fixed amount and stirred at a slow speed ff (10 to BO rpm), so that the fine flocs are lengthened into large flocs. Note that the polymer flocculant added in the flocculation tank 50 has a pH range of 4.
．． Those that act effectively with 5 to 6,5, such as nonionic or anionic terpolymer copolymers, can be preferably used. In addition, the retention period of wastewater in the flocculation tank 50 is generally 15 to 3
It should be about 0 minutes. The human waste wastewater that has been formed into flocs by the above-mentioned flocculation treatment is processed into a sedimentation tank, as necessary, as in the past.
Floating portion! It is supplied to a tank or a concentration screen, etc. to separate the coagulated flocs. That is, in the settling tank, the flocs are settled and separated from the treated water. In the floating fraction N tank, wastewater containing flocculated flocs from the flocculation tank is pressurized, air of approximately the same pressure is supplied to it to dissolve the air in the wastewater, and then the pressure is reduced to generate microbubbles. to make the flocs adhere to the flocs and float the flocs. In this way, the flocs are concentrated and separated from the treated PP water. In the concentration screen, the flocs are removed by a screen or the like and separated from the treated water by filtration. FIG. 2 shows another example of the inorganic flocculant 1jI-feeding device in the inorganic flocculant addition device of the present invention, and the same components as in FIG. . The structure differs from that in FIG. 1 in that a control valve 35 is used in place of the metered injection bomb 31 in FIG. Accordingly, the regulator 22 has a part of the function of the operating device IN of the inorganic flocculant supply device in FIG.
Valve actuation air 23 is output from the control well 35 so that the opening degree of the regulating well 35 can be appropriately controlled. In the control valve 35, the opening degree of the valve is adjusted by the valve operating air 23 via a diaphragm or the like, and the amount of inorganic flocculant added is controlled. Note that the injection pump 36 in FIG. 2 may be omitted, and the inorganic coagulant may be transferred from the inorganic coagulant tank 32 to the control valve 35 by the height difference. Also :j! 4@Valve 35 may be replaced with a solenoid valve for on/off control. Experimental Example The inorganic flocculant addition method of the present invention was carried out at a human waste facility using a standard denitrification treatment method as shown in FIG. 4, which removes ammonia from human waste wastewater along with BOD and COD. Wastewater treatment at this facility is performed as follows. The human waste and septic tank sludge that are temporarily received in the holding tank via each receiving tank are filtered by screens in the pre-treatment process and flow into the diluted camellia. Here, human waste and septic tank sludge are mixed and diluted by about 10 times or less with dilution water. The diluted mixed waste liquid passes through the first denitrification tank (stirring tank) and is maintained under aerobic oxidation conditions for nitrification #f! The organic nitrogen and ammonia nitrogen in the mixed waste liquid are nitrified and the BOD
Removal of the substance takes place. Most of the mixed solution in the nitrification tank containing nitrite nitrogen and nitrate nitrogen produced by nitrification is circulated (returned) to the first denitrification tank. This first denitrification tank is maintained under anaerobic reducing conditions, and a mixed waste liquid of diluted human waste and septic tank sludge, a mixed liquid circulated from the nitrification tank, and return sludge returned from the settling tank are mixed. It has been retained. The subacidic nitrogen and nitrate nitrogen produced by nitrification in the nitrification tank and circulated to the first denitrification tank convert the BOD components of the mixed waste liquid of human waste and septic tank sludge that flowed into the first denitrification tank into organic carbon. It is reduced to nitrogen gas by the facultative anaerobic gas used as a source, denitrified, and this BOD component is also removed. Next, the mixed liquid that has passed through the first denitrification tank and nitrification tank is introduced into the second denitrification tank maintained under anaerobic reduction conditions, and
The remaining nitrite nitrogen and nitrate nitrogen that were not reduced in the denitrification tank are reduced to nitrogen gas and denitrified. In this case, some methanol is supplementarily added into the second denitrification tank to accelerate the rate of reduction of nitrite nitrogen and nitrate nitrogen to nitrogen gas. The denitrified mixture that has passed through the second denitrification tank is then sent to the re-aerated camellia, where it is aerated with air to remove residual BOD components and degas the gas adhering to the activated sludge. Then, the treated water and activated sludge are separated in a settling tank, and the treated water is further led to a coagulation separation step. The flocculation and separation process is comprised of a mixing tank equipped with a pHgl and a rapid stirrer, a flocculation tank equipped with a slow imparter, and a settling tank. The mixing tank is further equipped with a metering bomb that supplies a fixed amount of inorganic flocculant to the mixing tank, and the flocculation tank is equipped with a metering pump that supplies a constant El (j') of polymer flocculant. The treated water treated in the process is discharged through an ozone oxidation process, a sand filtration process, an activated carbon treatment process, and a disinfection process.In this human waste treatment facility, in this experimental example, the coagulation separation process is shown in FIG. By adding a pH adjuster such as
The conventional method of adjusting pH was modified to the method of the present invention, which adjusts pH only by adding an inorganic flocculant, as shown in FIG. Sulfuric acid band was used as the inorganic flocculant added to the mixing tank, and the amount of the inorganic flocculant added was controlled using a pH meter so that the pH of the water to be treated in the mixing tank was 5.5. In addition, as the polymer flocculant added to the flocculant, an anionic polymer flocculant ``Aronfloc'' (trade name, manufactured by Toa Gosho Co., Ltd.) was used. In addition, the alkalinity of human waste, which is raw water, is 5000 to 700.
Even though the alkalinity of the inflow water from the coagulation separation process, which was diluted about 10 times with well water, was about 5000 mg/p, there was almost no change. Tables 2 and 3 summarize the amount of chemicals used and the quality of inflow water and treated water in the coagulation separation process in this experimental example. For comparison, the results of the conventional method shown in FIG. 5 (using a pH adjuster) are also shown in Tables 2 and 3. As can be seen from Tables 2 and 3, according to the method of the present invention, not only can 0.04 kg of caustic soda (pH adjuster) be saved per 1 m3 of treated water without changing the treated water quality, but also the inorganic flocculant The usage amount is also 10mg per 12 treated water.
I was able to save some money. Is this 100kj of human waste? The annual savings of approximately 3,100,000 liters of sodium hydroxide (caustic soda of approximately 2,000,000 liters and inorganic coagulant of approximately 1,100,000 liters) will be achieved at the treatment facility. It should be noted that the above-mentioned Examples are for explaining preferred embodiments of the present invention, and the present invention is not limited only to these Examples. For example, in the above embodiment, an example was shown in which an inorganic flocculant was added and stirred in a mixing tank, but the stirring operation according to the present invention is not limited to such an example,
It is also possible to add an inorganic flocculant to the blue distribution and stir it by a flow during the blue distribution, by passing it through a pump, etc. Furthermore, in the above-mentioned embodiments, an example was explained in which the coagulation and precipitation was carried out in a continuous manner, but it goes without saying that it may be carried out in a batch manner.
. Furthermore, in the above-mentioned embodiment, an example was explained in which the addition of an inorganic flocculant is controlled by detecting only the pH of the liquid, but for example, the flow rate of treated water flowing into the flocculation process is also detected, It is also possible to use control such as feed forward, in which the addition rate of the inorganic flocculant is increased when the inflow rate increases from a predetermined flow rate, and the addition rate of the inorganic flocculant is slowed down when the inflow rate decreases from a predetermined flow rate. Effects of the Invention As can be seen from the above, according to the present invention, when coagulating wastewater from human waste, the pH value of the wastewater is adjusted by adding only an inorganic flocculant, and the pH value is adjusted to a predetermined value. The amount added is controlled so that it falls within the range of {R composition, so effective aggregation treatment can be performed without using a pH adjuster, and the amount of pH adjuster can be reduced accordingly. Furthermore, according to the present invention, since the required amount of the inorganic flocculant itself can be reduced, together with the reduction in the amount of the pH adjuster,
Economically advantageous and efficient coagulation treatment of human waste wastewater becomes possible.
第１図はこの発明の好ましい実施例を示す説明図；第２
図は第１図の実施例の一部変形例を示す説明図；第３図
はこの発明の装置のブロックダイヤグラム；第４図は標
嘲脱窒素処理方式のし尿処理施設にこの発明の無機凝集
剤添加方法を組込んだ方式を示す説明図；および第５図
は従来の連続式凝集処理装置を示す説明図である。
１．１０・・・ｐｎセンサ、
２，２０・・・制御ｆ段、
３．３０・・・無機凝集剤供給装置。
第２図FIG. 1 is an explanatory diagram showing a preferred embodiment of this invention;
The figure is an explanatory diagram showing a partial modification of the embodiment shown in Figure 1; Figure 3 is a block diagram of the apparatus of the present invention; Figure 4 is a diagram showing the inorganic aggregation of the present invention in a human waste treatment facility using the denitrification treatment method. An explanatory diagram showing a method incorporating the agent addition method; and FIG. 5 is an explanatory diagram showing a conventional continuous agglomeration processing apparatus. 1.10... pn sensor, 2,20... control f stage, 3.30... inorganic flocculant supply device. Figure 2
Claims (1)
００ｍｇ／ｌを有するし尿廃水に凝集剤を添加するに際
して、し尿廃水のｐＨ値を無機凝集剤の添加のみによっ
て調整するとともに、該廃水のｐＨ値が４．５〜６．５
の範囲となるように無機凝集剤の添加量を制御すること
を特徴とする凝集剤の添加方法。 ２、生物処理が施されかつアルカリ度３０００〜１２０
００ｍｇ／ｌを有するし尿廃水の流路に設けられ該廃水
のｐＨを測定するｐＨセンサと、該流路に無機凝集剤を
添加供給する無機凝集剤供給装置と、該ｐＨセンサによ
るｐＨ測定値をｐＨ４．５〜６．５の範囲内の設定目標
値と比較してその偏差を最少にする制御信号を該供給装
置へ出力し該供給装置から該流路への無機凝集剤供給量
を制御する制御手段とからなることを特徴とする無機凝
集剤の添加装置。[Claims] 1. Biologically treated and alkalinity 3000-120
When adding a flocculant to human waste wastewater having a concentration of 0.00 mg/l, the pH value of the human waste wastewater is adjusted only by the addition of the inorganic flocculant, and the pH value of the waste water is 4.5 to 6.5.
A method for adding a flocculant, which comprises controlling the amount of the inorganic flocculant added so that the amount falls within the range of . 2. Biologically treated and alkalinity 3000-120
A pH sensor installed in a flow path of human waste wastewater having a pH of 0.00 mg/l to measure the pH of the wastewater, an inorganic flocculant supply device that adds and supplies an inorganic flocculant to the flow path, and a pH value measured by the pH sensor. A control signal that minimizes the deviation compared with a set target value within the range of pH 4.5 to 6.5 is output to the supply device to control the amount of inorganic flocculant supplied from the supply device to the flow path. An apparatus for adding an inorganic flocculant, characterized by comprising a control means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15630189A JPH0321392A (en) | 1989-06-19 | 1989-06-19 | Coagulant adding method and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15630189A JPH0321392A (en) | 1989-06-19 | 1989-06-19 | Coagulant adding method and apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0321392A true JPH0321392A (en) | 1991-01-30 |
Family
ID=15624820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15630189A Pending JPH0321392A (en) | 1989-06-19 | 1989-06-19 | Coagulant adding method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0321392A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7491337B2 (en) | 2004-04-23 | 2009-02-17 | Jeffbrad Investments Pty Limited | Method and apparatus for removing contaminants from water |
| JP2011088051A (en) * | 2009-10-21 | 2011-05-06 | Ihi Corp | Waste liquid treatment equipment and waste liquid treatment method |
| JP2014094351A (en) * | 2012-11-09 | 2014-05-22 | Gunbiru:Kk | Effluent treatment apparatus |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5933000A (en) * | 1982-08-12 | 1984-02-22 | Mitsubishi Electric Corp | Dehydration treatment method for human waste digested sludge |
| JPS5992091A (en) * | 1982-11-19 | 1984-05-28 | Mitsubishi Heavy Ind Ltd | Disposal of waste liquor |
| JPS59139993A (en) * | 1983-01-28 | 1984-08-11 | Oriental Yeast Co Ltd | Waste liquid treatment method |
| JPS60139383A (en) * | 1983-12-28 | 1985-07-24 | Nishihara Environ Sanit Res Corp | Treatment of waste water |
| JPS6391107A (en) * | 1986-10-03 | 1988-04-21 | Nittetsu Mining Co Ltd | How to treat wastewater |
-
1989
- 1989-06-19 JP JP15630189A patent/JPH0321392A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5933000A (en) * | 1982-08-12 | 1984-02-22 | Mitsubishi Electric Corp | Dehydration treatment method for human waste digested sludge |
| JPS5992091A (en) * | 1982-11-19 | 1984-05-28 | Mitsubishi Heavy Ind Ltd | Disposal of waste liquor |
| JPS59139993A (en) * | 1983-01-28 | 1984-08-11 | Oriental Yeast Co Ltd | Waste liquid treatment method |
| JPS60139383A (en) * | 1983-12-28 | 1985-07-24 | Nishihara Environ Sanit Res Corp | Treatment of waste water |
| JPS6391107A (en) * | 1986-10-03 | 1988-04-21 | Nittetsu Mining Co Ltd | How to treat wastewater |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7491337B2 (en) | 2004-04-23 | 2009-02-17 | Jeffbrad Investments Pty Limited | Method and apparatus for removing contaminants from water |
| JP2011088051A (en) * | 2009-10-21 | 2011-05-06 | Ihi Corp | Waste liquid treatment equipment and waste liquid treatment method |
| JP2014094351A (en) * | 2012-11-09 | 2014-05-22 | Gunbiru:Kk | Effluent treatment apparatus |
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