JP2007260556A - Phosphoric acid-containing wastewater treatment method and apparatus - Google Patents
Phosphoric acid-containing wastewater treatment method and apparatus Download PDFInfo
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- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title claims abstract description 150
- 229910000147 aluminium phosphate Inorganic materials 0.000 title claims abstract description 75
- 238000004065 wastewater treatment Methods 0.000 title abstract description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 93
- 239000002351 wastewater Substances 0.000 claims abstract description 85
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical class [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 claims abstract description 48
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 40
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 37
- 239000011574 phosphorus Substances 0.000 claims abstract description 37
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 37
- 229910052742 iron Inorganic materials 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 20
- 230000001112 coagulating effect Effects 0.000 claims 1
- 238000005345 coagulation Methods 0.000 abstract description 3
- 230000015271 coagulation Effects 0.000 abstract description 3
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 22
- 230000002776 aggregation Effects 0.000 description 18
- 230000002829 reductive effect Effects 0.000 description 14
- 238000004220 aggregation Methods 0.000 description 13
- 239000012528 membrane Substances 0.000 description 13
- 239000010802 sludge Substances 0.000 description 13
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 11
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- 238000001223 reverse osmosis Methods 0.000 description 9
- 238000003756 stirring Methods 0.000 description 9
- 238000007792 addition Methods 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 6
- 238000006386 neutralization reaction Methods 0.000 description 6
- 238000001556 precipitation Methods 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 5
- 238000011109 contamination Methods 0.000 description 5
- 239000004973 liquid crystal related substance Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 238000011084 recovery Methods 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 229920006318 anionic polymer Polymers 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- -1 iron ions Chemical class 0.000 description 3
- 229910000398 iron phosphate Inorganic materials 0.000 description 3
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 239000011733 molybdenum Substances 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- 230000004931 aggregating effect Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 229910001424 calcium ion Inorganic materials 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000008394 flocculating agent Substances 0.000 description 2
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000036961 partial effect Effects 0.000 description 2
- 229920002401 polyacrylamide Polymers 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- 240000001973 Ficus microcarpa Species 0.000 description 1
- 229910021576 Iron(III) bromide Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000012851 eutrophication Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 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
- KAEAMHPPLLJBKF-UHFFFAOYSA-N iron(3+) sulfide Chemical compound [S-2].[S-2].[S-2].[Fe+3].[Fe+3] KAEAMHPPLLJBKF-UHFFFAOYSA-N 0.000 description 1
- PVFSDGKDKFSOTB-UHFFFAOYSA-K iron(3+);triacetate Chemical compound [Fe+3].CC([O-])=O.CC([O-])=O.CC([O-])=O PVFSDGKDKFSOTB-UHFFFAOYSA-K 0.000 description 1
- WHRBSMVATPCWLU-UHFFFAOYSA-K iron(3+);triformate Chemical compound [Fe+3].[O-]C=O.[O-]C=O.[O-]C=O WHRBSMVATPCWLU-UHFFFAOYSA-K 0.000 description 1
- SUBFIBLJQMMKBK-UHFFFAOYSA-K iron(3+);trithiocyanate Chemical compound [Fe+3].[S-]C#N.[S-]C#N.[S-]C#N SUBFIBLJQMMKBK-UHFFFAOYSA-K 0.000 description 1
- NPFOYSMITVOQOS-UHFFFAOYSA-K iron(III) citrate Chemical compound [Fe+3].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NPFOYSMITVOQOS-UHFFFAOYSA-K 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 description 1
- 239000011736 potassium bicarbonate Substances 0.000 description 1
- 229910000028 potassium bicarbonate Inorganic materials 0.000 description 1
- 235000015497 potassium bicarbonate Nutrition 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 235000011181 potassium carbonates Nutrition 0.000 description 1
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 description 1
- 229940086066 potassium hydrogencarbonate Drugs 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 229940047670 sodium acrylate Drugs 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 description 1
- FEONEKOZSGPOFN-UHFFFAOYSA-K tribromoiron Chemical compound Br[Fe](Br)Br FEONEKOZSGPOFN-UHFFFAOYSA-K 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
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Abstract
Description
本発明は、リン酸含有排水の処理方法及び処理装置に関する。さらに詳しくは、本発明は、半導体製造工場、液晶製造工場などで多量に使用されるリン酸を含有する洗浄排水について、少量の鉄(III)塩を用いて水中のリン酸を効率的に凝集させ、除去することができるリン酸含有排水の処理方法及び処理装置に関する。 The present invention relates to a method and apparatus for treating phosphoric acid-containing wastewater. In more detail, the present invention efficiently aggregates phosphoric acid in water using a small amount of iron (III) salt for washing wastewater containing phosphoric acid used in large quantities in semiconductor manufacturing plants, liquid crystal manufacturing plants, etc. It is related with the processing method and processing apparatus of the phosphoric acid containing waste water which can be made to remove.
半導体製造工場、液晶製造工場などから排出される洗浄排水は、その主成分としてリン酸を含む場合がある。リン酸を含有する排水が系外に排出されると、湖沼などの閉鎖性水域や、河川、沿岸などで水質の富栄養化が起こる。また、液晶製造工場などでは、水資源の節約と環境汚染の防止のために、排水の回収利用が行われているが、リン酸含有排水中のリン酸を除去しきれず、後段の逆浸透膜処理における膜汚染へと繋がる場合がある。したがって、リン酸含有排水中のリン酸を適切に除去する必要がある。 Cleaning wastewater discharged from semiconductor manufacturing plants, liquid crystal manufacturing plants, and the like may contain phosphoric acid as its main component. When wastewater containing phosphoric acid is discharged outside the system, eutrophication of water quality occurs in closed water areas such as lakes and marshes, rivers, and coasts. Also, liquid crystal manufacturing factories are collecting and using wastewater to save water resources and prevent environmental pollution. However, phosphoric acid in wastewater containing phosphoric acid cannot be completely removed, and the reverse osmosis membrane in the latter stage It may lead to membrane contamination in the process. Therefore, it is necessary to appropriately remove phosphoric acid in the phosphoric acid-containing waste water.
リン酸含有排水中のリン酸を除去する方法として、カルシウムイオンによりリン酸カルシウムを生成させて除去する方法、塩化鉄(III)や硫化鉄(III)などの鉄系凝集剤及び高分子凝集剤を用いる凝集沈殿方法がある。しかし、液晶製造工場などで排水を回収する場合は、その後の生物処理又は膜処理に影響を与えるカルシウムイオンの使用を避けている。鉄系凝集剤による凝集では、適用できるｐＨは５〜１０.５とされている（非特許文献１）が、ｐＨ６〜８程度の中性域で凝集することが一般的に行われている。ｐＨ６〜８程度で凝集処理する理由は、凝集剤に含まれる鉄イオンが水酸化物をとりこみやすいｐＨ領域で凝集が行われることによりフロックが大きくなり、凝集に適している（非特許文献２）とされてきたためである。 As a method for removing phosphoric acid from phosphoric acid-containing wastewater, a method in which calcium phosphate is generated and removed by calcium ions, iron-based flocculants such as iron (III) chloride and iron (III) sulfide, and polymer flocculants are used. There is a coagulation precipitation method. However, when wastewater is collected at a liquid crystal manufacturing plant or the like, the use of calcium ions that affect subsequent biological treatment or membrane treatment is avoided. In agglomeration with an iron-based aggregating agent, the applicable pH is 5 to 10.5 (Non-patent Document 1), but agglomeration is generally performed in a neutral range of about pH 6 to 8. The reason for the aggregation treatment at a pH of about 6 to 8 is that the flocs are increased in the pH region where the iron ions contained in the flocculent easily take in hydroxides, which is suitable for aggregation (Non-patent Document 2). It is because it has been said.
凝集剤の添加量は、あらかじめ手動分析でリン酸濃度を測定し、鉄系凝集剤を鉄とリンのモル比（Ｆｅ／Ｐ）が１.８程度の一定量で添加している場合が多い。しかし、このｐＨ領域で凝集を行うと、水酸化物イオンが取り込まれることにより、鉄の荷電中和力が低下し、リン酸と鉄の反応性が低下してしまうことがわかった。鉄とリン酸の反応としては、下式のような当モル反応が考えられるが、上記の理由で鉄に水酸化物イオンが取り込まれる場合、鉄のモル量をリン酸のモル量に対して、１.８倍程度にしなければならない。
Ｆｅ3＋＋ ＰＯ4 3- → ＦｅＰＯ4
The amount of the flocculant added is often determined by measuring the phosphoric acid concentration by manual analysis in advance, and adding an iron-based flocculant in a fixed amount with an iron to phosphorus molar ratio (Fe / P) of about 1.8. . However, it has been found that when aggregation is performed in this pH region, the neutralization power of iron decreases due to the incorporation of hydroxide ions, and the reactivity between phosphoric acid and iron decreases. As the reaction between iron and phosphoric acid, an equimolar reaction as shown in the following formula is conceivable, but when hydroxide ions are incorporated into iron for the above reasons, the molar amount of iron is set to the molar amount of phosphoric acid. It must be about 1.8 times.
Fe 3+ + PO 4 3- → FePO 4
凝集剤の使用量が多いと、凝集剤コストが高くなるのみならず、凝集剤を中和する薬品の使用量の増加や、汚泥の発生量の増加などを引き起こす。また、処理水中の塩濃度が高くなり、後段に逆浸透膜処理などがある場合には、逆浸透膜の差圧の上昇を引き起こすなど、数多くの悪影響を及ぼす。
本発明は、半導体製造工場、液晶製造工場などで多量に使用されるリン酸を含有する洗浄排水について、少量の鉄(III)塩を用いて水中のリン酸を効率的に凝集させ、除去することができるリン酸含有排水の処理方法及び処理装置を提供することを目的としてなされたものである。 The present invention efficiently removes phosphoric acid in water by using a small amount of iron (III) salt for washing wastewater containing phosphoric acid used in large quantities in semiconductor manufacturing plants, liquid crystal manufacturing plants, etc. It is made for the purpose of providing the processing method and processing apparatus of the phosphoric acid containing waste water which can be carried out.
本発明者は、上記の課題を解決すべく鋭意研究を重ねた結果、リン酸含有排水のｐＨを４〜６の領域に調整し、被処理水中の鉄濃度が、排水中のリン濃度と特定の関係になるように鉄(III)塩を添加することにより、鉄(III)塩の添加量を減少し、しかも処理水のリン濃度を効率的に低下させ得ることを見いだし、この知見に基づいて本発明を完成するに至った。 As a result of intensive studies to solve the above problems, the present inventor has adjusted the pH of the phosphoric acid-containing wastewater to a region of 4 to 6, and the iron concentration in the treated water is determined to be the phosphorus concentration in the wastewater. Based on this finding, it was found that adding iron (III) salt to reduce the amount of iron (III) salt added and effectively reducing the phosphorus concentration of treated water. The present invention has been completed.
すなわち、本発明は、
（１）リン酸を含有する排水に鉄(III)塩を添加して凝集処理する方法において、排水のｐＨを４〜６の領域に調整して、鉄濃度が式［１］の範囲となるように排水に鉄(III)塩を添加することを特徴とするリン酸含有排水の処理方法、
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
（ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８である。）、及び、
（２）リン酸を含有する排水に鉄(III)塩を添加して凝集処理する水処理装置において、排水のリン酸濃度を自動的に測定し、排水のｐＨを４〜６の領域に調整し、演算器を用いて、排水中の鉄濃度が式［１］の範囲となるように、排水に添加する鉄(III)塩の量を自動的に制御することを特徴とするリン酸含有排水の処理装置、
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
（ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８である。）、
を提供するものである。
That is, the present invention
(1) In a method in which iron (III) salt is added to wastewater containing phosphoric acid and agglomeration treatment is performed, the pH of the wastewater is adjusted to a range of 4 to 6, and the iron concentration falls within the range of the formula [1]. To treat wastewater containing phosphoric acid, characterized by adding iron (III) salt to the wastewater,
Fe = (0.2 × pH + A) × P (1)
(In Formula [1], Fe is the iron concentration (mol / L), P is the phosphorus concentration (mol / L) in the waste water, and A is 0.3 to 0.8). as well as,
(2) In a water treatment device that adds iron (III) salt to waste water containing phosphoric acid and agglomerates, the phosphoric acid concentration in the waste water is automatically measured, and the pH of the waste water is adjusted to the range of 4-6. And using a calculator, the amount of iron (III) salt added to the wastewater is automatically controlled so that the iron concentration in the wastewater falls within the range of the formula [1]. Wastewater treatment equipment,
Fe = (0.2 × pH + A) × P (1)
(In Formula [1], Fe is the iron concentration (mol / L), P is the phosphorus concentration (mol / L) in the waste water, and A is 0.3 to 0.8).
Is to provide.
本発明のリン酸含有排水の処理方法によれば、ｐＨ４〜６の領域で、リン濃度と特定の関係にある量の鉄(III)塩を添加することにより、鉄(III)塩の使用量を低減させることができ、かつ、リン濃度の低い処理水を得ることができる。鉄(III)塩の使用量の減少により、汚泥発生量が低減する。また、鉄(III)塩の使用量の減少により、中和に要する薬品の使用量も低減することができ、塩類濃度の低い処理水を得ることができる。処理水の塩類濃度が低くなると、後段に逆浸透膜などの水回収設備がある場合、逆浸透膜などの汚染を低減し、差圧上昇を抑えることができる。逆浸透膜などの汚染を低減させることにより、膜の洗浄回数を減少させ、排水の回収を合理化することができる。本発明のリン酸含有排水の処理装置によれば、排水のリン酸濃度を自動的に測定し、リン濃度に応じて、添加する鉄(III)塩の量を短時間で自動制御により変更し、鉄(III)塩の添加量を常に最適に保つことにより鉄(III)塩の使用量を低減し、リン濃度の低い安定した水質の処理水を得ることができる。 According to the method for treating phosphoric acid-containing wastewater of the present invention, the amount of iron (III) salt used by adding an amount of iron (III) salt having a specific relationship with the phosphorus concentration in the pH range of 4-6. In addition, it is possible to obtain treated water having a low phosphorus concentration. Sludge generation is reduced by reducing the amount of iron (III) salt used. Further, by reducing the amount of iron (III) salt used, the amount of chemicals required for neutralization can be reduced, and treated water having a low salt concentration can be obtained. When the salt concentration of the treated water is low, when there is a water recovery facility such as a reverse osmosis membrane in the subsequent stage, contamination of the reverse osmosis membrane or the like can be reduced and an increase in the differential pressure can be suppressed. By reducing the contamination of reverse osmosis membranes, etc., the number of membrane washings can be reduced, and wastewater recovery can be rationalized. According to the phosphoric acid-containing wastewater treatment apparatus of the present invention, the phosphoric acid concentration of the wastewater is automatically measured, and the amount of iron (III) salt to be added is changed by automatic control in a short time according to the phosphorus concentration. By always keeping the addition amount of iron (III) salt optimal, the amount of iron (III) salt used can be reduced and stable treated water with low phosphorus concentration can be obtained.
本発明のリン酸含有排水の処理方法においては、リン酸を含有する排水に鉄(III)塩を添加して凝集処理する方法において、排水のｐＨを４〜６、より好ましくは４.３〜５の領域に調整して、鉄濃度が式［１］の範囲となるように排水に鉄(III)塩を添加する。
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８、より好ましくは０.４〜０.７である。
In the method of treating phosphoric acid-containing wastewater of the present invention, the pH of the wastewater is 4 to 6, more preferably 4.3 to 3, in the method of adding iron (III) salt to the wastewater containing phosphoric acid and aggregating it. The iron (III) salt is added to the waste water so that the iron concentration falls within the range of the formula [1].
Fe = (0.2 × pH + A) × P (1)
However, in Formula [1], Fe is an iron concentration (mol / L), P is a phosphorus concentration (mol / L) in waste water, A is 0.3-0.8, More preferably, it is 0.8. 4 to 0.7.
本発明に用いる鉄(III)塩は、水溶性を有する塩であれば特に制限はなく、例えば、塩化鉄(III)、臭化鉄(III)、硫酸鉄(III)、硝酸鉄(III)、チオシアン酸鉄(III)、ギ酸鉄(III)、酢酸鉄(III)、クエン酸鉄(III)などを挙げることができる。これらの中で、塩化鉄(III)を好適に用いることができる。 The iron (III) salt used in the present invention is not particularly limited as long as it is a water-soluble salt, for example, iron (III) chloride, iron (III) bromide, iron (III) sulfate, iron (III) nitrate. And iron (III) thiocyanate, iron (III) formate, iron (III) acetate, iron (III) citrate and the like. Among these, iron (III) chloride can be suitably used.
図１は、リン酸含有排水に鉄(III)塩を添加して凝集処理するとき、リン酸が効果的に除去される領域のｐＨとＦｅ／Ｐ（モル比）の関係を示すグラフである。従来は、リン酸が効果的に除去されるｐＨ領域は、ｐＨ６〜８であると考えられ、Ｆｅ／Ｐ（モル比）１.８程度の図１にＢで示す領域で処理が行われてきた。ｐＨが６未満であると、プラス荷電が強くなりすぎて凝集不良が生じ、ｐＨが８を超えると、プラス荷電が弱くなりすぎて凝集不良が生ずると考えられていた。 FIG. 1 is a graph showing the relationship between pH and Fe / P (molar ratio) in a region where phosphoric acid is effectively removed when an iron (III) salt is added to a phosphoric acid-containing wastewater for agglomeration treatment. . Conventionally, the pH region where phosphoric acid is effectively removed is considered to be pH 6-8, and the treatment has been performed in the region indicated by B in FIG. 1 where the Fe / P (molar ratio) is about 1.8. It was. When the pH is less than 6, the positive charge becomes too strong and causes poor aggregation, and when the pH exceeds 8, the positive charge becomes too weak and causes poor aggregation.
驚くべきことに、プラス荷電が強くなりすぎて凝集不良が生ずると考えられているｐＨ６未満の領域においても、鉄(III)塩の添加量を減少することにより、リン酸鉄の良好な凝集が起こることが分かった。リン酸鉄の良好な凝集が起こる領域は、図１にＡで示す領域である。この領域は、ｐＨ４〜６であり、Ｆｅ／Ｐ（モル比）が（０.２×ｐＨ＋Ａ）（ただし、Ａ＝０.３〜０.８）である領域である。ｐＨが４未満であると、鉄(III)塩の添加量をさらに減少しても、プラス荷電が強くなりすぎて凝集不良が生ずるおそれがある。Ｆｅ／Ｐ（モル比）が（０.２×ｐＨ＋０.３）未満であると、鉄(III)塩の量が不足して、凝集不良が生ずるおそれがある。Ｆｅ／Ｐ（モル比）が（０.２×ｐＨ＋０.８）を超えると、鉄(III)塩の量が過剰となり、汚泥量が増大する。また、鉄(III)塩量の増大でプラス荷電過多となり、凝集不良も生じるおそれがある。 Surprisingly, good aggregation of iron phosphate can be achieved by reducing the amount of iron (III) salt added even in the region of less than pH 6, which is considered to cause aggregation failure due to excessive positive charge. I know it will happen. The region where good aggregation of iron phosphate occurs is the region indicated by A in FIG. This region is a region having a pH of 4 to 6 and Fe / P (molar ratio) of (0.2 × pH + A) (where A = 0.3 to 0.8). If the pH is less than 4, even if the addition amount of the iron (III) salt is further reduced, the positive charge becomes too strong and there is a possibility that poor aggregation occurs. If the Fe / P (molar ratio) is less than (0.2 × pH + 0.3), the amount of iron (III) salt is insufficient, and there is a risk of poor aggregation. When Fe / P (molar ratio) exceeds (0.2 × pH + 0.8), the amount of iron (III) salt becomes excessive and the amount of sludge increases. In addition, an increase in the amount of iron (III) salt results in excessive positive charge, which may cause poor aggregation.
本発明方法において、ｐＨ４〜６の範囲で鉄(III)塩の使用量を減らして、リン酸鉄の良好な凝集を起こし得る理由は、ｐＨを４〜６の低ｐＨ領域は、鉄の電荷が強くなり、鉄とリン酸の凝集反応性が向上するためと推定される。本発明方法によれば、リン酸と鉄の反応性が向上するために、鉄(III)塩の使用量を大幅に減少させることができる。本発明方法により形成される凝集フロックは、ｐＨ６.５〜７で凝集させたときと同等の沈降性を有する。 In the method of the present invention, the amount of iron (III) salt used can be reduced in the range of pH 4 to 6 to cause good aggregation of iron phosphate. The reason for the low pH range of pH 4 to 6 is that This is presumably because the agglomeration reactivity of iron and phosphoric acid is improved. According to the method of the present invention, since the reactivity between phosphoric acid and iron is improved, the amount of iron (III) salt used can be greatly reduced. The aggregated floc formed by the method of the present invention has a sedimentation property equivalent to that when aggregated at pH 6.5-7.
本発明方法においては、リン酸含有排水のｐＨを４〜６の領域に調整して鉄(III)塩を加えて凝集反応を起こさせたのちに、中和と、高分子凝集剤の添加による凝集フロックの粗大化を行うことが好ましい。中和に用いるアルカリに特に制限はなく、例えば、水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム、炭酸カリウム、炭酸水素ナトリウム、炭酸水素カリウムなどを挙げることができる。凝集フロックの粗大化には、アニオン性高分子凝集剤を好適に用いることができる。アニオン性高分子凝集剤としては、例えば、ポリアクリル酸ナトリウム、アクリル酸ナトリウムとアクリルアミドの共重合体、ポリアクリルアミドの部分加水分解物、２−アクリルアミド−２−メチルプロパンスルホン酸共重合体などを挙げることができる。 In the method of the present invention, after adjusting the pH of the phosphoric acid-containing wastewater to a region of 4 to 6 and adding an iron (III) salt to cause an aggregation reaction, neutralization and addition of a polymer flocculant are performed. It is preferable to coarsen the aggregated floc. There is no restriction | limiting in particular in the alkali used for neutralization, For example, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate etc. can be mentioned. An anionic polymer flocculant can be suitably used for coarsening the flocs. Examples of the anionic polymer flocculant include sodium polyacrylate, a copolymer of sodium acrylate and acrylamide, a partial hydrolyzate of polyacrylamide, and a 2-acrylamide-2-methylpropanesulfonic acid copolymer. be able to.
本発明のリン酸含有排水の処理装置は、リン酸を含有する排水に鉄(III)塩を添加して凝集処理する水処理装置において、排水のリン酸濃度を自動的に測定し、排水のｐＨを４〜６の領域に調整し、演算器を用いて、排水中の鉄濃度が式［１］の範囲となるように、排水に添加する鉄(III)塩の量を自動的に制御する処理装置である。
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８である。
The treatment apparatus for wastewater containing phosphoric acid according to the present invention is a water treatment apparatus that adds iron (III) salt to wastewater containing phosphoric acid and agglomerates to automatically measure the phosphoric acid concentration of the wastewater. Adjust the pH to the range of 4-6 and use the calculator to automatically control the amount of iron (III) salt added to the waste water so that the iron concentration in the waste water is within the range of equation [1]. Is a processing device.
Fe = (0.2 × pH + A) × P (1)
However, in Formula [1], Fe is iron concentration (mol / L), P is the phosphorus concentration (mol / L) in waste water, and A is 0.3-0.8.
本発明装置によれば、排水のリン酸濃度が時々刻々と変動する場合であっても、リン酸濃度測定装置と鉄(III)塩供給装置を演算器を介して連動させ、常に最適量の鉄(III)塩を排水に供給することができる。従来は、リン酸含有排水のリン酸濃度が大きく変動する場合には、ｐＨ６.５〜７の条件下では、Ｆｅ／Ｐ（モル比）を２.０程度まで高めて、安全サイドで運転する場合があったが、本発明装置によれば、鉄(III)塩の使用量を常に最適量に抑え、しかも効果的にリン酸処理を行うことができる。本発明装置に用いるリン酸濃度測定装置に特に制限はなく、例えば、リンバナドモリブデン酸比色法、モリブデン青吸光光度法などによる測定装置を挙げることができる。 According to the device of the present invention, even when the phosphoric acid concentration of the waste water fluctuates from moment to moment, the phosphoric acid concentration measuring device and the iron (III) salt supply device are interlocked via the arithmetic unit, and the optimum amount is always maintained. Iron (III) salt can be supplied to the wastewater. Conventionally, when the phosphoric acid concentration of the phosphoric acid-containing waste water greatly fluctuates, the Fe / P (molar ratio) is increased to about 2.0 under the condition of pH 6.5 to 7 and the operation is performed on the safe side. In some cases, according to the apparatus of the present invention, the amount of iron (III) salt used can always be suppressed to an optimum amount, and phosphoric acid treatment can be performed effectively. There is no restriction | limiting in particular in the phosphoric acid concentration measuring apparatus used for this invention apparatus, For example, the measuring apparatus by a phosphovanadomolybdic acid colorimetric method, a molybdenum blue absorptiometry, etc. can be mentioned.
以下に、実施例を挙げて本発明をさらに詳細に説明するが、本発明はこれらの実施例によりなんら限定されるものではない。
実施例１
２００５年１２月１日から２８日まで、半導体製造工場で排出されるリン酸含有排水の処理を行った。この間、リン酸含有排水のリン濃度は、０.６ミリモル／Ｌから２.７ミリモル／Ｌの範囲で変動した。
図２は、試験に用いた装置の説明図である。リン酸を含有する排水を９０Ｌ／ｈで原水槽１に導入してｐＨを調整し、急速撹拌槽２に導入して所定量の塩化鉄(III)を加えた。次いで、緩速撹拌槽３に導入して水酸化ナトリウム水溶液を用いて中和し、さらにアニオン性高分子凝集剤を添加して凝集フロックを粗大化させた。凝集フロックが粗大化した被処理水は、沈殿槽４へ送り、固液分離して処理水を得た。
原水槽において、リン酸含有排水のｐＨを４.５に調整した。１２時間に１回、排水のリン酸濃度を吸光光度計を用いて、モリブデン青法により測定し、鉄Ｆｅの濃度がリンＰの濃度に対して次式で表される量となるように、急速撹拌槽に塩化鉄(III)水溶液を添加した。
Ｆｅ ＝ (０.２×４.５＋０.５９)×Ｐ ＝ １.４９×Ｐ
緩速撹拌槽において、水酸化ナトリウム水溶液を用いて中和し、ポリアクリルアミド部分加水分解物０.５ｍｇ／Ｌを添加した。１２時間ごとに、排水のリン酸濃度の測定を行い、必要な場合には、塩化鉄(III)水溶液の添加量を変更した。沈殿槽において固液分離し、沈殿槽から流出する処理水のリン酸濃度を測定し、リン濃度を算出した。沈殿槽から引き抜かれる汚泥の重量と水分率を求め、発生する汚泥の乾燥重量を算出した。
試験期間中の処理水のリン濃度は０.０８〜０.１２ミリモル／Ｌであり、発生する汚泥の乾燥重量は１日平均５５ｋｇであった。
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1
From December 1st to 28th, 2005, the wastewater containing phosphoric acid discharged from the semiconductor manufacturing plant was treated. During this time, the phosphorus concentration of the phosphoric acid-containing waste water varied in the range of 0.6 mmol / L to 2.7 mmol / L.
FIG. 2 is an explanatory diagram of the apparatus used for the test. The wastewater containing phosphoric acid was introduced into the raw water tank 1 at 90 L / h to adjust the pH, and introduced into the
In the raw water tank, the pH of the phosphoric acid-containing wastewater was adjusted to 4.5. Once every 12 hours, the phosphoric acid concentration of the wastewater is measured by a molybdenum blue method using an absorptiometer, and the concentration of iron Fe becomes an amount represented by the following formula with respect to the concentration of phosphorus P. An aqueous iron (III) chloride solution was added to the rapid stirring tank.
Fe = (0.2 × 4.5 + 0.59) × P = 1.49 × P
The mixture was neutralized with an aqueous sodium hydroxide solution in a slow stirring tank, and 0.5 mg / L of polyacrylamide partial hydrolyzate was added. Every 12 hours, the phosphoric acid concentration of the waste water was measured, and when necessary, the amount of iron (III) chloride aqueous solution added was changed. Solid-liquid separation was performed in the precipitation tank, the phosphoric acid concentration of the treated water flowing out of the precipitation tank was measured, and the phosphorus concentration was calculated. The weight and moisture content of the sludge withdrawn from the settling tank were determined, and the dry weight of the generated sludge was calculated.
The phosphorus concentration of the treated water during the test period was 0.08 to 0.12 mmol / L, and the dry weight of the generated sludge was 55 kg on average per day.
実施例２
実施例１と同じ期間、実施例１と並行して、リン濃度の自動測定と、塩化鉄(III)水溶液の添加量の自動制御を行って、リン酸含有排水の処理を行った。
図２に示す実施例１と同規格の装置の原水槽１内に、連続式のリン酸濃度計［ＨＡＣＨ社、分析法：リンバナド法］を設置した。リン酸を含有する排水を９０Ｌ／ｈで原水槽に導入して、ｐＨを４.５に調整した。リン酸濃度計で測定されたリン酸濃度にもとづき、２０分ごとに、鉄Ｆｅの濃度がリンＰの濃度に対して次式で表される量となるように自動制御して、急速撹拌槽に塩化鉄(III)水溶液を添加した。
Ｆｅ ＝ (０.２×４.５＋０.５１)×Ｐ ＝ １.４１×Ｐ
緩速撹拌槽における中和と高分子凝集剤の添加、沈殿槽における固液分離、処理水のリン濃度の算出、汚泥の発生量の算出は、実施例１と同様にして行った。
試験期間中の処理水のリン濃度は０.０３〜０.０８ミリモル／Ｌであり、発生する汚泥の乾燥重量は１日平均４９ｋｇであった。
Example 2
In the same period as in Example 1, in parallel with Example 1, phosphoric acid-containing wastewater was treated by automatically measuring the phosphorus concentration and automatically controlling the amount of iron (III) chloride added.
A continuous phosphoric acid concentration meter [HACH, Analytical method: Limbanad method] was installed in the raw water tank 1 of the apparatus of the same standard as in Example 1 shown in FIG. The wastewater containing phosphoric acid was introduced into the raw water tank at 90 L / h to adjust the pH to 4.5. Based on the phosphoric acid concentration measured with a phosphoric acid concentration meter, the rapid stirring tank is automatically controlled so that the concentration of iron Fe becomes the amount represented by the following formula with respect to the concentration of phosphorus P every 20 minutes. To the solution was added an aqueous iron (III) chloride solution.
Fe = (0.2 × 4.5 + 0.51) × P = 1.41 × P
Neutralization in a slow stirring tank and addition of a polymer flocculant, solid-liquid separation in a precipitation tank, calculation of the phosphorus concentration of treated water, and calculation of the amount of sludge generated were performed in the same manner as in Example 1.
The phosphorus concentration of the treated water during the test period was 0.03 to 0.08 mmol / L, and the dry weight of the generated sludge was 49 kg on average per day.
比較例１
実施例１と同じ期間、実施例１と並行して、リン濃度の手動測定と、塩化鉄(III)水溶液の添加量の制御を行って、リン酸含有排水の処理を行った。
図２に示す実施例１と同規格の装置の原水槽１内に、リン酸を含有する排水を９０Ｌ／ｈで原水槽に導入して、ｐＨを６.５に調整し、１２時間に１回、排水のリン酸濃度を吸光度計を用いて、モリブデン青法により測定し、鉄Ｆｅの濃度がリンＰの濃度に対して次式で表される量となるように、急速撹拌槽に塩化鉄(III)水溶液を添加した以外は、実施例１と同じ操作を行った。
Ｆｅ ＝ (０.２×６.５＋０.５０)×Ｐ ＝ １.８０×Ｐ
試験期間中の処理水のリン濃度は０.０６〜０.３２ミリモル／Ｌであり、発生する汚泥の乾燥重量は１日平均１０８ｋｇであった。
実施例１〜２及び比較例１の結果を、第１表に示す。
Comparative Example 1
In the same period as in Example 1, in parallel with Example 1, phosphoric acid-containing wastewater was treated by manually measuring the phosphorus concentration and controlling the amount of iron (III) chloride aqueous solution added.
The waste water containing phosphoric acid is introduced into the raw water tank at 90 L / h in the raw water tank 1 of the apparatus of the same standard as Example 1 shown in FIG. Measure the concentration of phosphoric acid in the waste water by the molybdenum blue method using an absorptiometer, and chlorinate it in the rapid stirring tank so that the concentration of iron Fe is the amount expressed by the following formula with respect to the concentration of phosphorus P The same operation as in Example 1 was performed except that an iron (III) aqueous solution was added.
Fe = (0.2 × 6.5 + 0.50) × P = 1.80 × P
The phosphorus concentration of the treated water during the test period was 0.06 to 0.32 mmol / L, and the dry weight of the generated sludge was 108 kg on average per day.
The results of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.
第１表に見られるように、排水のｐＨを４.５に調整し、１２時間ごとに、求めた排水のリンＰ濃度に応じて、Ｆｅ／Ｐ（モル比）が１.４９となるように、塩化鉄(III)水溶液の添加量を制御した実施例１では、処理水のリン濃度が低く、リン濃度のばらつきも小さい。また、平均汚泥発生量が少ない。 As can be seen in Table 1, the pH of the waste water is adjusted to 4.5, and the Fe / P (molar ratio) becomes 1.49 according to the obtained phosphorus P concentration of the waste water every 12 hours. In addition, in Example 1 in which the addition amount of the iron (III) chloride aqueous solution was controlled, the phosphorus concentration of the treated water was low and the variation in the phosphorus concentration was small. In addition, the average amount of sludge generated is small.
排水のｐＨを４.５に調整し、２０分ごとに、自動測定した排水のリンＰ濃度に応じて、Ｆｅ／Ｐ（モル比）が１.４１となるように、塩化鉄(III)水溶液の添加量を自動制御した実施例２では、処理水のリン濃度がさらに低く、平均汚泥発生量もさらに少ない。 The pH of the waste water is adjusted to 4.5, and an iron (III) chloride aqueous solution so that the Fe / P (molar ratio) becomes 1.41 according to the phosphorus P concentration of the waste water automatically measured every 20 minutes. In Example 2 in which the amount of addition was automatically controlled, the phosphorus concentration of the treated water was even lower, and the average sludge generation amount was even smaller.
これに対して、排水のｐＨを６.５に調整し、１２時間ごとに、求めた排水のリンＰ濃度に応じて、Ｆｅ／Ｐ（モル比）が１.８０となるように、塩化鉄(III)水溶液の添加量を制御した比較例１では、平均汚泥発生量が多いにもかかわらず、処理水のリン濃度のばらつきが大きく、リン濃度が高くなっている。 On the other hand, the pH of the wastewater is adjusted to 6.5, and the iron chloride is adjusted so that the Fe / P (molar ratio) becomes 1.80 according to the obtained phosphorus P concentration of the wastewater every 12 hours. (III) In Comparative Example 1 in which the amount of the aqueous solution added was controlled, the variation in the phosphorus concentration of the treated water was large and the phosphorus concentration was high despite the large amount of average sludge generation.
本発明のリン酸含有排水の処理方法によれば、ｐＨ４〜６の領域で、リン濃度と特定の関係にある量の鉄(III)塩を添加することにより、凝集剤の使用量を低減させることができ、かつ、リン濃度の低い処理水を得ることができる。鉄(III)塩の使用量の減少により、汚泥発生量が低減する。また、鉄(III)塩の使用量の減少により、中和に要する薬品の使用量も低減することができ、塩類濃度の低い処理水を得ることができる。処理水の塩類濃度が低くなると、後段に逆浸透膜などの水回収設備がある場合、逆浸透膜など汚染を低減し、差圧上昇を抑えることができる。逆浸透膜などの汚染を低減させることにより、膜の洗浄回数を減少させ、排水の回収を合理化することができる。本発明のリン酸含有排水の処理装置によれば、排水のリン酸濃度を自動的に測定し、リン濃度に応じて、添加する鉄(III)塩の量を短時間で自動制御により変更し、鉄(III)塩の添加量を常に最適に保つことにより鉄(III)塩の使用量を低減し、リン濃度の低い安定した水質の処理水を得ることができる。 According to the method for treating phosphoric acid-containing wastewater of the present invention, the amount of the flocculant used is reduced by adding an iron (III) salt having a specific relationship with the phosphorus concentration in the pH range of 4-6. And treated water with a low phosphorus concentration can be obtained. Sludge generation is reduced by reducing the amount of iron (III) salt used. Further, by reducing the amount of iron (III) salt used, the amount of chemicals required for neutralization can be reduced, and treated water having a low salt concentration can be obtained. When the salt concentration of the treated water is low, if there is a water recovery facility such as a reverse osmosis membrane in the subsequent stage, contamination such as a reverse osmosis membrane can be reduced and an increase in the differential pressure can be suppressed. By reducing the contamination of reverse osmosis membranes, etc., the number of membrane washings can be reduced, and wastewater recovery can be rationalized. According to the phosphoric acid-containing wastewater treatment apparatus of the present invention, the phosphoric acid concentration of the wastewater is automatically measured, and the amount of iron (III) salt to be added is changed by automatic control in a short time according to the phosphorus concentration. By always keeping the addition amount of iron (III) salt optimal, the amount of iron (III) salt used can be reduced and stable treated water with low phosphorus concentration can be obtained.
１ 原水槽
２ 急速撹拌槽
３ 緩速撹拌槽
４ 沈殿槽
1
Claims (2)
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
（ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８である。） In the method of adding iron (III) salt to the wastewater containing phosphoric acid and coagulating, the wastewater is adjusted so that the pH of the wastewater is in the range of 4 to 6 and the iron concentration is in the range of the formula [1]. A method for treating phosphoric acid-containing wastewater, wherein iron (III) salt is added to the waste water.
Fe = (0.2 × pH + A) × P (1)
(However, in Formula [1], Fe is an iron concentration (mol / L), P is a phosphorus concentration (mol / L) in waste water, and A is 0.3 to 0.8.)
Ｆｅ ＝ (０.２×ｐＨ＋Ａ)×Ｐ …［１］
（ただし、式［１］において、Ｆｅは鉄濃度（モル／Ｌ）であり、Ｐは排水中のリン濃度（モル／Ｌ）であり、Ａは０.３〜０.８である。） In a water treatment device that adds iron (III) salt to wastewater containing phosphoric acid and agglomerates it, the phosphoric acid concentration of the wastewater is automatically measured, and the pH of the wastewater is adjusted to a range of 4 to 6 to calculate Treatment of phosphoric acid-containing wastewater characterized by automatically controlling the amount of iron (III) salt added to the wastewater so that the iron concentration in the wastewater falls within the range of the formula [1] using a vessel apparatus.
Fe = (0.2 × pH + A) × P (1)
(However, in Formula [1], Fe is an iron concentration (mol / L), P is a phosphorus concentration (mol / L) in waste water, and A is 0.3 to 0.8.)
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| WO2013033557A1 (en) * | 2011-09-01 | 2013-03-07 | Celanese International Corporation | Reduction of organic phosphorus acids |
| CN104623932A (en) * | 2014-12-30 | 2015-05-20 | 广东新明珠陶瓷集团有限公司 | Raw material residue wastewater recycling system and recovering method |
| WO2019018387A1 (en) * | 2017-07-18 | 2019-01-24 | Ecolab USA, Inc. | Recycling automotive phosphate rinse water stream |
| CN111392848A (en) * | 2020-04-08 | 2020-07-10 | 甘肃稀土新材料股份有限公司 | Accurate oxidation flocculation treatment method for reducing total phosphorus concentration in mixed wastewater in rare earth industry |
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| JP2005125152A (en) * | 2003-10-21 | 2005-05-19 | Kurita Water Ind Ltd | Water treatment method and water treatment apparatus |
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| JPH1099887A (en) * | 1996-09-27 | 1998-04-21 | Unitika Ltd | Apparatus for controlling addition amount of flocculant |
| JP2000254660A (en) * | 1999-03-09 | 2000-09-19 | Kankyo Eng Co Ltd | Removing method of phosphorus in industrial waste water |
| JP2005125152A (en) * | 2003-10-21 | 2005-05-19 | Kurita Water Ind Ltd | Water treatment method and water treatment apparatus |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2013033557A1 (en) * | 2011-09-01 | 2013-03-07 | Celanese International Corporation | Reduction of organic phosphorus acids |
| CN103842301A (en) * | 2011-09-01 | 2014-06-04 | 国际人造丝公司 | Reduction of organic phosphorus acids |
| US9346692B2 (en) | 2011-09-01 | 2016-05-24 | Celanese International Corporation | Reduction of organic phosphorus acids |
| CN103842301B (en) * | 2011-09-01 | 2018-04-06 | 醋酸纤维国际有限责任公司 | Reduce organic phosphorous acids |
| CN104623932A (en) * | 2014-12-30 | 2015-05-20 | 广东新明珠陶瓷集团有限公司 | Raw material residue wastewater recycling system and recovering method |
| WO2019018387A1 (en) * | 2017-07-18 | 2019-01-24 | Ecolab USA, Inc. | Recycling automotive phosphate rinse water stream |
| US11136246B2 (en) | 2017-07-18 | 2021-10-05 | Ecolab Usa Inc. | Recycling automotive phosphate rinse water stream |
| CN111392848A (en) * | 2020-04-08 | 2020-07-10 | 甘肃稀土新材料股份有限公司 | Accurate oxidation flocculation treatment method for reducing total phosphorus concentration in mixed wastewater in rare earth industry |
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