EP0000861A1 - Process for the purification of organically polluted, calcium containing wastewater - Google Patents
Process for the purification of organically polluted, calcium containing wastewater Download PDFInfo
- Publication number
- EP0000861A1 EP0000861A1 EP19780100051 EP78100051A EP0000861A1 EP 0000861 A1 EP0000861 A1 EP 0000861A1 EP 19780100051 EP19780100051 EP 19780100051 EP 78100051 A EP78100051 A EP 78100051A EP 0000861 A1 EP0000861 A1 EP 0000861A1
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- EP
- European Patent Office
- Prior art keywords
- wastewater
- containing gas
- purification
- activated sludge
- aeration
- 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.)
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- 239000002351 wastewater Substances 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title claims abstract description 12
- 239000011575 calcium Substances 0.000 title claims abstract description 10
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 title claims abstract description 8
- 229910052791 calcium Inorganic materials 0.000 title claims abstract description 8
- 238000000746 purification Methods 0.000 title claims abstract description 6
- 239000010802 sludge Substances 0.000 claims abstract description 23
- 239000007789 gas Substances 0.000 claims abstract description 14
- 238000005273 aeration Methods 0.000 claims abstract description 13
- 239000000126 substance Substances 0.000 claims abstract description 9
- 239000007788 liquid Substances 0.000 claims abstract description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000001301 oxygen Substances 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 4
- 239000002244 precipitate Substances 0.000 claims abstract description 4
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims abstract description 3
- 230000004913 activation Effects 0.000 claims abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 8
- 230000001580 bacterial effect Effects 0.000 description 6
- 230000015556 catabolic process Effects 0.000 description 5
- 238000006731 degradation reaction Methods 0.000 description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 description 4
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 4
- 239000000920 calcium hydroxide Substances 0.000 description 3
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 3
- 230000007850 degeneration Effects 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 2
- CZMRCDWAGMRECN-UHFFFAOYSA-N 2-{[3,4-dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy}-6-(hydroxymethyl)oxane-3,4,5-triol Chemical compound OCC1OC(CO)(OC2OC(CO)C(O)C(O)C2O)C(O)C1O CZMRCDWAGMRECN-UHFFFAOYSA-N 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/12—Activated sludge processes
- C02F3/1205—Particular type of activated sludge processes
- C02F3/1215—Combinations of activated sludge treatment with precipitation, flocculation, coagulation and separation of phosphates
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/12—Activated sludge processes
- C02F3/26—Activated sludge processes using pure oxygen or oxygen-rich gas
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Definitions
- the invention relates to a process for purifying organically contaminated wastewater containing calcium by means of an activated sludge process with aeration with virtually pure oxygen and / or with an oxygen-containing gas.
- Calcuim-containing, organically contaminated wastewater is generated in particular in sugar production.
- the sugar industry has recently used activated sludge processes either instead of or in connection with the use of stacking ponds and oxidation ponds for the purification of such waste water.
- a wastewater treatment process is known, in which the alluvial and wash water accumulating in the sugar factory is circulated through a settling tank and the sludge transport water coming from the settling tank is first fed to an on-board tank and an anaerobic tank and then to a fermenter with a downstream secondary settling tank.
- Sludge settled in the secondary clarifier is transported back into the fermenter, while purified water withdrawn from the secondary clarifier can be returned to the sedimentation basin of the wash and wash water circuit or fed to a receiving water.
- the fermenter can be operated with air or at least oxygen-enriched air (see special print from the magazine "Zucker", 28th year, issue 10, pages 527 to 534, 1975).
- a reduction in the bacterial growth in the activated sludge system and thus a low degradation capacity can be due to the fact that the wastewater accumulating in the sedimentation basin of the wash and wash water circuit due to the usually more or less high additions of calcium hydroxide (Ca (OH) 2 ) into the wash - and water cycle to avoid undesirable bacterial growth in this cycle is strongly alkaline, pH values up to 12 can be reached.
- Ca (OH) 2 calcium hydroxide
- the invention has for its object to develop a process for the purification of calcium-containing wastewater, in particular from sugar factories, of the type mentioned at the outset, with which, in a simple manner, despite the degeneration of the activated sludge which may occur and despite the high pH in the wastewater high degradation performance can be achieved.
- This object is achieved in that a C0 2 -containing gas is introduced into the liquid present in the aeration system at least temporarily and at least in part of the aeration system and so much C0 2 components are dissolved in the liquid that part of the water in the wastewater dissolved calcium precipitates.
- the invention takes advantage of the fact that C0 2 combines with calcium hydroxide to calcium carbonate and water. With the appearance of calcium carbonate, this is what Calcium hydroxide dissolved in wastewater is converted into an insoluble precipitate that can be easily removed. The more calcium hydroxide is converted into calcium carbonate, the lower the pH value of the wastewater and adjusts itself to a range in which the bacterial growth improves and the degradation performance is increased accordingly.
- the pH in the aeration system is set between 6 and 8, preferably between 6.5 and 7.5, since the acidity is only slightly or only slightly alkaline wastewater the bacterial growth is cheapest.
- the concentration of activated dry matter in the wastewater is above 8 kg / m3 and the proportion of the organic substance (defined as loss on ignition) therein to 30 to 70%, preferably 40 to 60%.
- the calcium carbonate precipitated by the introduction of a CO 2 -containing gas weighs the activated sludge and leads to an increase in the concentration of the activated sludge dry substance. which generally the weight fraction undissolved Specifies substances in a solid water mixture.
- the dry matter concentration increased rapidly in the course of a short time and reached values of 20 to 40 kg / m 3 with a glow loss of 40-50% and a sludge index of 20-50 ml / g.
- BOD 5 room load 5-10 kg / m 3 ⁇ d and a corresponding nominal aeration time of 30–60 hours
- BOD 5 values of 150–300 mg / l and COD values of 600– 1200 mg / 1 measured.
- the Ca content of the drain was 600 mg / l, ie it had decreased by 2400 mg / 1, which corresponds to a precipitated amount of 6000 mg / l CaCO 3 .
- the CaC0 3 When determining the ignition loss, the CaC0 3 practically completely changes to 3350 mg / l Ca0. About 2500 mg / l excess sludge with an organic content of approx. 70% is produced from 12000 mg / l BOD 5 .
- the table below shows that in this way a sludge with an organic content of approx. 21% and a loss on ignition (previously defined as organic substance) of approx. 50% was formed.
- the inorganic part causes the good flocculation and settling properties.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Microbiology (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Activated Sludge Processes (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
Zur Reinigung Calcium enthaltenden organisch belasteten Abwassers, insbesondere zur Reinigung von Abwasser aus Zuckerfabriken, wird ein entsprechendes Abwasser mittels eines Belebtschlammverfahrens unter Belüften mit nahezu reinem Sauerstoff und/oder mit einem Sauerstoff enthaltenden Gas behandelt. Dabei wird mindestens zeitweise und mindestens in einem Teil des Belebungssystems ein CO2-haltiges Gas in die im Belebungssystem vorhandene Flüssigkeit eingeleitet, und in dieser werden so viele CO2-Anteile gelöst, dass ein Teil des im Abwasser gelösten Calciums als Niederschlag ausfällt. Die Einleitung des CO2-haltigen Gases kann in dem Mass durchgeführt werden, dass der pH-Wert im Belebungssystem auf einen Wert zwischen 6 und 8, insbesondere zwischen 6,5 und 7,5 eingestellt und die Konzentration an Belebtschlammtrockensubstanz über 8 kg/m³ und der Anteil der organischen Substanz darin, definiert als Glühverlust, auf 30 bis 70%, vorzugsweise auf 40 bis 60%, gehalten wird.For the purification of organically contaminated wastewater containing calcium, in particular for the purification of wastewater from sugar factories, a corresponding wastewater is treated by means of an activated sludge process with aeration with almost pure oxygen and / or with an oxygen-containing gas. At least temporarily and at least in part of the aeration system, a CO2-containing gas is introduced into the liquid in the aeration system, and so many CO2 components are dissolved in it that part of the calcium dissolved in the wastewater precipitates. The introduction of the CO2-containing gas can be carried out to the extent that the pH in the activation system is set to a value between 6 and 8, in particular between 6.5 and 7.5, and the concentration of activated sludge dry substance is above 8 kg / m³ and the proportion of the organic substance therein, defined as loss on ignition, is kept at 30 to 70%, preferably at 40 to 60%.
Description
Die Erfindung betrifft ein Verfahren zur Reinigung Calcium enthaltenden organisch belasteten Abwassers mittels eines Belebtschlammverfahrens unter Belüften mit nahezu reinem Sauerstoff und bzw. oder mit einem Sauerstoff enthaltenden Gas.The invention relates to a process for purifying organically contaminated wastewater containing calcium by means of an activated sludge process with aeration with virtually pure oxygen and / or with an oxygen-containing gas.
Calcuim enthaltende, organisch belastete Abwässer fallen insbesondere bei der Zuckerherstellung an. Von der Zuckerindustrie werden neuerdings zur Reinigung solcher Abwässer Belebtschlammverfahren entweder anstelle oder in Verbindung mit der Verwendung von Stapelteichen und Oxydationsteichen eingesetzt. So ist beispielsweise ein Abwasserreinigungsverfahren bekannt, bei dem das in der Zuckerfabrik anfallende Schwemm-und Waschwasser im Kreislauf über ein Absetzbecken geführt und das vom Absetzbecken kommende Schlammtransportwasser zunächst einem Auflandebecken und einem Anaerobbecken und danach einem Fermenter mit nachgeschaltetem Nachklärbecken zugeleitet wird. Im Nachklärbecken abgesetzter Schlamm wird in den Fermenter zurücktransportiert, während aus dem Nachklärbecken abgezogenes gereinigtes Wasser in das Absetzbecken des Schwemm- und Waschwasserkreises zurück-oder einem Vorfluter zugeleitet werden kann. Der Fermenter kann dabei mit Luft oder zumindest mit Sauerstoff angereicherter Luft betrieben werden (siehe Sonderdruck aus der Zeitschrift "Zucker", 28. Jahrgang, Heft 10, Seite 527 bis 534, 1975).Calcuim-containing, organically contaminated wastewater is generated in particular in sugar production. The sugar industry has recently used activated sludge processes either instead of or in connection with the use of stacking ponds and oxidation ponds for the purification of such waste water. For example, a wastewater treatment process is known, in which the alluvial and wash water accumulating in the sugar factory is circulated through a settling tank and the sludge transport water coming from the settling tank is first fed to an on-board tank and an anaerobic tank and then to a fermenter with a downstream secondary settling tank. Sludge settled in the secondary clarifier is transported back into the fermenter, while purified water withdrawn from the secondary clarifier can be returned to the sedimentation basin of the wash and wash water circuit or fed to a receiving water. The fermenter can be operated with air or at least oxygen-enriched air (see special print from the magazine "Zucker", 28th year, issue 10, pages 527 to 534, 1975).
Wie sich gezeigt hat, verläuft der Betrieb solcher Kläranlagen nicht immer reibungslos. Häufig treten unkontrollierte Entartungen des Belebtschlammes auf, die erhebliche Störungen der Abbauleistung zur Folge haben und die auf ein unausgewogenes Nährstoffangebot insbesondere bei Über- oder Unterbelastung der Anlagen zurückzuführen sind. Solche als Blähschlamm bezeichneten Entartungen können beispielsweise lange Bakterienfäden sein, die nur eine geringe Sinkgeschwindigkeit besitzten. Beim Auftreten eines solchen Blähschlamms erfolgt im Nachklärbecken nur eine sehr langsame Auftrennung in den Belebtschlamm, der in die Belebungsanlage zurückgenommen wird und in den Klarlauf, der in den Vorfluter abgeleitet wird.As has been shown, the operation of such wastewater treatment plants is not always smooth. Uncontrolled degenerations of the activated sludge often occur, which result in considerable disruption of the degradation performance and which can be attributed to an unbalanced nutrient supply, especially when the plants are overloaded or underloaded. Such degenerations, known as expanding sludge, can be, for example, long bacterial threads that have only a low sinking rate. When such expansion sludge occurs, there is only a very slow separation into the activated sludge in the secondary clarifier, which is taken back into the aeration plant and into the clear run, which is discharged into the receiving water.
Darüber hinaus kann auch eine Verminderung des Bakterienwachstums im Belebtschlammsystem und damit eine geringe Abbauleistung dadurch bedingt sein, daß das im Absetzbecken des Schwemm- und Waschwasserkreislaufs anfallende Abwasser aufgrund der üblicherweise mehr oder minder hohen Zugaben von Calciumhydroxid (Ca(OH)2) in den Schwemm- und Wasserkreislauf zur Vermeidung eines in diesem Kreislauf unerwünschten Bakterienwachstums stark alkalisch ist, wobei pH-Werte bis zu 12 erreicht werden können.In addition, a reduction in the bacterial growth in the activated sludge system and thus a low degradation capacity can be due to the fact that the wastewater accumulating in the sedimentation basin of the wash and wash water circuit due to the usually more or less high additions of calcium hydroxide (Ca (OH) 2 ) into the wash - and water cycle to avoid undesirable bacterial growth in this cycle is strongly alkaline, pH values up to 12 can be reached.
Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren zur Reinigung Calcium enthaltenden Abwassers,insbesondere aus Zuckerfabriken, der eingangs genannten Art zu entwickeln, mit dem auf einfache Weise trotz der unter Umständen auftretenden Entartungen des Belebtschlamms und trotz des hohen pH-Wertes im Abwasser eine möglichst hohe Abbauleistung erzielt werden kann.The invention has for its object to develop a process for the purification of calcium-containing wastewater, in particular from sugar factories, of the type mentioned at the outset, with which, in a simple manner, despite the degeneration of the activated sludge which may occur and despite the high pH in the wastewater high degradation performance can be achieved.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß mindestens zeitweise und mindestens in einem Teil des Belebungssystems ein C02-haltiges Gas in die im Belebungssystem vorhandene Flüssigkeit eingeleitet wird und dabei soviel C02-Anteile in der Flüssigkeit gelöst werden, daß ein Teil des im Abwasser gelösten Calciums als Niederschlag ausfällt.This object is achieved in that a C0 2 -containing gas is introduced into the liquid present in the aeration system at least temporarily and at least in part of the aeration system and so much C0 2 components are dissolved in the liquid that part of the water in the wastewater dissolved calcium precipitates.
Die Erfindung macht sich den Umstand zunutze, daß sich C02 mit Calciumhydroxid zu Calciumcarbonat und Wasser verbindet. Mit dem Auftreten von Calciumcarbonat wird also das im Abwasser gelöste Calciumhydroxid in einen unlöslichen Niederschlag übergeführt, der leicht entfernt werden kann. Je mehr Calciumhydroxid dabei in Calciumcarbonat übergeführt wird, desto geringer wird der pH-Wert des Abwassers und stellt sich auf einen Bereich ein, in dem das Bakterienwachstum verbessert und die Abbauleistung entsprechend erhöht wird.The invention takes advantage of the fact that C0 2 combines with calcium hydroxide to calcium carbonate and water. With the appearance of calcium carbonate, this is what Calcium hydroxide dissolved in wastewater is converted into an insoluble precipitate that can be easily removed. The more calcium hydroxide is converted into calcium carbonate, the lower the pH value of the wastewater and adjusts itself to a range in which the bacterial growth improves and the degradation performance is increased accordingly.
Vorteilhaft ist es dabei, die Einleitung des C02- haltigen Gases in dem Maß durchzuführen, daß der pH-Wert im Belebungssystem zwischen 6 und 8, vorzugsweise zwischen 6,5 und 7,5 eingestellt wird, da bei nur gering saurem oder nur gering alkalischem Abwasser das Bakterienwachstum am günstigsten ist. Zur Einstellung.dieser pH-Werte ist es lediglich erforderlich, die Menge des eingeleiteten C02-haltigen Gases in Abhängigkeit eines zum Beispiel im Ablauf des Abwassers gemessenen pH-Wertes zu regeln.It is advantageous to carry out the introduction of the CO 2 -containing gas to the extent that the pH in the aeration system is set between 6 and 8, preferably between 6.5 and 7.5, since the acidity is only slightly or only slightly alkaline wastewater the bacterial growth is cheapest. To set these pH values, it is only necessary to regulate the amount of the introduced CO 2 -containing gas depending on a pH value measured, for example, in the effluent.
Darüberhinaus erweist es sich als vorteilhaft, die Einleitung des C02-haltigen Gases in dem Maß durchzuführen, daß die Konzentration an Belebtsehlammtrockensubstanz im Abwasser über 8 kg/m3 und der Anteil der organischen Substanz(definiert als Glühverlust)darin auf 30 bis 70 %, vorzugsweise auf 40 bis 60 %, gehalten wird. Das durch das Einleiten eines C02-haltigen Gases ausgefällte Calciumcarbonat beschwert den Belebtschlamm und führt zu einer Erhöhung der Konzentration der Belebtschlammtrockensubstanz. die allgemein den Gewichtsanteil ungelöster Stoffe eines Feststoffwassergemisches angibt. Dadurch können die Ausbildung und/oder die Auswirkungen des Blähschlamms weitgehend unterbunden und die Sinkgeschwindigkeit auch von fadenförmigen Bakterien in der Nachklärzone erhöht werden, so daß der vorhandene Belebtschlamm schneller in die Belebtzone zurückgeführt werden kann und dadurch letztlich mehr organische Substanz (= Bakterienmasse) zur Verfügung steht. Eine Erhöhung der Abbauleistung ist die Folge.In addition, it proves advantageous to carry out the introduction of the CO 2 -containing gas to the extent that the concentration of activated dry matter in the wastewater is above 8 kg / m3 and the proportion of the organic substance (defined as loss on ignition) therein to 30 to 70%, preferably 40 to 60%. The calcium carbonate precipitated by the introduction of a CO 2 -containing gas weighs the activated sludge and leads to an increase in the concentration of the activated sludge dry substance. which generally the weight fraction undissolved Specifies substances in a solid water mixture. As a result, the formation and / or the effects of the expanded sludge can be largely prevented and the sinking rate of filiform bacteria in the secondary clarification zone can be increased, so that the existing activated sludge can be returned to the activated zone more quickly and ultimately more organic substance (= bacterial mass) is available stands. The result is an increase in the mining capacity.
Wie sich gezeigt hat, lassen sich mit den vorstehend angegegebenen Werten gute Abbauleistungen erzielen. Ein Zahlenbeispiel soll diese Zusammenhänge verdeutlichen:
- Abwasser aus dem Schwemm- und Waschwasserkreislauf einer Zuckerfabrik wurde aus dem Ablauf des mechanischen Absetzbeckens entnommen und einer halbtechnischen biologischen Anlage zugeleitet. Der BSB5 des Zulaufs betrug 12000 mg/1, der CSB 17000 mg/1, der pH-Wert 10-12 und der Ca-Gehalt 3000 mg/1. Das Belebungsbecken der Anlage war zu Beginn mit Belebtschlamm einer kommunalen Kläranlage gefüllt worden, der durch eine Trockensubstanzkonzentration von 4 kg/m3, einen Glühverlust von 80 % und einen Schlammindex von 100 ml/g gekennzeichnet war. Im Belebungsbecken wurde ein Gas eingetragen, das 60-70 % 02 und 30-40 % C02 enthielt. Hierdurch stellte sich im Becken ein pH-Wert von 6,5 - 7 ein.
- Waste water from the wash and wash water circuit of a sugar factory was taken from the drain of the mechanical sedimentation basin and sent to a semi-technical biological plant. The BOD 5 of the feed was 12000 mg / 1, the COD 17000 mg / 1, the pH 10-12 and the Ca content 3000 mg / 1. The aeration tank of the plant was initially filled with activated sludge from a municipal sewage treatment plant, which was characterized by a dry matter concentration of 4 kg / m3, a loss on ignition of 80% and a sludge index of 100 ml / g. A gas containing 60-70% 0 2 and 30-40% C0 2 was introduced into the activation tank. This resulted in a pH of 6.5 - 7 in the pool.
Die Trockensubstanzkonzentration nahm im Verlauf kurzer Zeit stark zu und erreichte Werte von 20 bis 40 kg/m3 mit einem Glühverlust von 40-50 % und einem Schlammindex von 20-50 ml/g. Bei einer BSB5-Raumbelastung von 5-10 kg/m3·d und einer entsprechenden nominellen Belüftungszeit von 30-60 Std. wurden im Ablauf des Nachklärbeckens BSB5-Werte von 150-300 mg/l und CSB-Werte von 600-1200 mg/1 gemessen. Der Ca-Gehalt des Ablaufs lag bei 600 mg/l, hatte also um 2400 mg/1 abgenommen, was einer ausgefällten Menge von 6000 mg/l CaCO3 entspricht. Bei Bestimmung des Glühverlustes geht das CaC03 praktisch völlig in 3350 mg/l Ca0 über. Aus 12000 mg/l BSB5 entstehen etwa 2500 mg/l Überschußschlamm mit einem organischen Anteil von ca. 70 %. Die anschließende Tabelle zeigt, daß auf diese Weise ein Schlamm mit einem organischen Anteil von ca. 21 % und einem Glühverlust (zuvor definiert als organische Substanz) von ca. 50 % entstanden ist. Der anorganische Anteil bewirkt die guten Flockungs- und Absetzeigenschaften.
Claims (4)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19772738309 DE2738309A1 (en) | 1977-08-25 | 1977-08-25 | METHOD FOR CLEANING CALCIUM-CONTAINING ORGANICALLY BURNISHED WASTE WATER |
| DE2738309 | 1977-08-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0000861A1 true EP0000861A1 (en) | 1979-03-07 |
| EP0000861B1 EP0000861B1 (en) | 1981-08-12 |
Family
ID=6017266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19780100051 Expired EP0000861B1 (en) | 1977-08-25 | 1978-06-01 | Process for the purification of organically polluted, calcium containing wastewater |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4227998A (en) |
| EP (1) | EP0000861B1 (en) |
| BR (1) | BR7805506A (en) |
| DE (1) | DE2738309A1 (en) |
| IT (1) | IT1098172B (en) |
| ZA (1) | ZA784822B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL7906426A (en) * | 1979-08-27 | 1981-03-03 | Gist Brocades Nv | METHOD FOR PURIFYING WASTE WATER. |
| DE3202212A1 (en) * | 1982-01-25 | 1983-08-04 | Süddeutsche Zucker AG, 6800 Mannheim | METHOD FOR ANAEROBICLY DEGRADING CALCIUMION-CONTAINING, ALKALINE FLOOD AND WASHING WATERS |
| DE3917415C2 (en) * | 1989-05-29 | 1999-01-14 | Linde Ag | Wastewater treatment processes |
| GB9425110D0 (en) * | 1994-12-13 | 1995-02-08 | Boc Group Plc | Sewage respiration inhibition |
| DE10062878A1 (en) * | 2000-12-16 | 2002-06-27 | Messer Griesheim Gmbh | Processes for biological wastewater treatment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3356609A (en) * | 1966-05-03 | 1967-12-05 | United Carbide Corp | Aerobic treatment of sewage |
| US3546111A (en) * | 1968-05-13 | 1970-12-08 | Ethyl Corp | Waste treatment |
| FR2294986A1 (en) * | 1974-12-22 | 1976-07-16 | Agrotechnika Np | PROCESS AND DEVICE FOR PURIFYING WASTEWATER IN INDUSTRY AND AGRICULTURE |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2196840A (en) * | 1935-10-11 | 1940-04-09 | Micajah T Singleton | Sewage treatment |
| DE1484838A1 (en) * | 1964-02-04 | 1969-06-04 | Metallgesellschaft Ag | Process for the treatment of centrifugate, which falls during the dewatering of sewage sludge by means of decanting centrifuges |
| US3440166A (en) * | 1967-06-13 | 1969-04-22 | North American Rockwell | Waste treatment process with recycling flocculating agents |
| US3640820A (en) * | 1969-08-22 | 1972-02-08 | Nalco Chemical Co | Sewage treatment process |
| US3947350A (en) * | 1972-10-30 | 1976-03-30 | Envirotech Corporation | Process of preparing sewage sludge for dewatering |
| DE2535837C3 (en) * | 1975-08-12 | 1984-09-13 | Bayer Ag, 5090 Leverkusen | Process for the biological treatment of wastewater in a cascade |
-
1977
- 1977-08-25 DE DE19772738309 patent/DE2738309A1/en not_active Withdrawn
-
1978
- 1978-06-01 EP EP19780100051 patent/EP0000861B1/en not_active Expired
- 1978-08-15 US US05/933,838 patent/US4227998A/en not_active Expired - Lifetime
- 1978-08-21 IT IT2686978A patent/IT1098172B/en active
- 1978-08-24 ZA ZA00784822A patent/ZA784822B/en unknown
- 1978-08-24 BR BR7805506A patent/BR7805506A/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3356609A (en) * | 1966-05-03 | 1967-12-05 | United Carbide Corp | Aerobic treatment of sewage |
| US3546111A (en) * | 1968-05-13 | 1970-12-08 | Ethyl Corp | Waste treatment |
| FR2294986A1 (en) * | 1974-12-22 | 1976-07-16 | Agrotechnika Np | PROCESS AND DEVICE FOR PURIFYING WASTEWATER IN INDUSTRY AND AGRICULTURE |
Non-Patent Citations (1)
| Title |
|---|
| CHEMICAL ABSTRACTS, vol. 86, no. 14, April 4, 1977, COLUMBUS, Ohio (USA) H. TEICHMANN et al.: "The biological purification of waste water from sugar refineries", page 383, abstract 95491y * |
Also Published As
| Publication number | Publication date |
|---|---|
| IT1098172B (en) | 1985-09-07 |
| IT7826869A0 (en) | 1978-08-21 |
| US4227998A (en) | 1980-10-14 |
| ZA784822B (en) | 1979-08-29 |
| EP0000861B1 (en) | 1981-08-12 |
| DE2738309A1 (en) | 1979-03-15 |
| BR7805506A (en) | 1979-04-17 |
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