NO751626L - - Google Patents

Info

Publication number
NO751626L
NO751626L NO751626A NO751626A NO751626L NO 751626 L NO751626 L NO 751626L NO 751626 A NO751626 A NO 751626A NO 751626 A NO751626 A NO 751626A NO 751626 L NO751626 L NO 751626L
Authority
NO
Norway
Prior art keywords
stated
hydrogen
waste water
procedure
treated
Prior art date
Application number
NO751626A
Other languages
Norwegian (no)
Inventor
C Piccinini
F Federici
Original Assignee
Tecneco Spa
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tecneco Spa filed Critical Tecneco Spa
Publication of NO751626L publication Critical patent/NO751626L/no

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/70Treatment of water, waste water, or sewage by reduction
    • C02F1/705Reduction by metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/34Auxiliary operations
    • B29C44/36Feeding the material to be shaped
    • B29C44/46Feeding the material to be shaped into an open space or onto moving surfaces, i.e. to make articles of indefinite length
    • B29C44/467Foam spreading or levelling devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/34Auxiliary operations
    • B29C44/58Moulds
    • B29C44/588Moulds with means for venting, e.g. releasing foaming gas
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/52Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00Moulds or cores; Details thereof or accessories therefor
    • B29C33/10Moulds or cores; Details thereof or accessories therefor with incorporated venting means
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C37/00Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
    • B29C37/006Degassing moulding material or draining off gas during moulding

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Treatment Of Water By Oxidation Or Reduction (AREA)
  • Removal Of Specific Substances (AREA)
  • Catalysts (AREA)

Description

Fremgangsmåte for rensing av spillvann. Procedure for cleaning waste water.

Foreliggende oppfinnelse vedrører en fremgangsmåte for rensingThe present invention relates to a method for cleaning

av spillvann som inneholder krom, kvikksølv og andre turigmetall-forbindelser, og det særegne ved fremgangsmåten i henhold til oppfinnelsen er at spillvannet bringes i' kontakt med et element valgt fra de elementer som er mindre edle enn hydrogen* ;I>et er kjent fra vitenskapelige publikasjoner at det er foreslått en fremgangsmåte for reduksjon av.:Cr<+>^ til Cr<+>^ hvor det gjøres bruk a<y>metallisk jern. Denne fremgangsmåte har imidlertid ikke funnet industriell anvendelse i scirlig grad'fremfor alt på grunn av det høye forbruk av jern, som forer til store mengder slam som må fjernes og et forbruk.av fellingsmidde! (CatOH^ eller NaOH) høyere enn dem som opptrer ved de vanlige prosesser (SO^ og bisulfit) ;På den annen side er 'det klart at hvis reaksjonen foregikk med et Fe-f or bruk tilsvarende det teoretiske, ville prosessen være fordelaktig fra et økonomisk synspunkt. ;Det er nå funnet at hvis pH i den oppløsning som skal behandles og den ltneare hastighet derav i det reduserende system reguleres på passende måte, er det mulig å gjennomføre fremgangsmåten med et jernforbruk meget nær den teoretiske verdi uten samtidig opptreden av passiveringsfenomener for metallet, idet disse fenomener skyldes dannelsen av-en. passivert film på raetalloverflaten som i løpet av noen tid fullstendig deaktiverer metallet. Hvis pH i avløpet fra det reduserende system holdes under den verdi ved hvilken Fe felles ut som hydroksyd, unngås disse fenomener fullstendig. ;Mer spesielt gjennomfores f reragangsmåten i henhold til oppfinnelsen ved å la det vann som skal behandles stromme gjennom en eller flere kolonner fylt med elementet som er mindre edelt enn hydrogen, idet det element foreligger i form av korn, kuler, små stenger, spon. eller hvilken som helst form som kan tilpasses s størrelsen av selve kolonnene. ;Den reaksjon som foregår hår vannet strømmer gjennom kolonnene består i oksydasjon av elementet i 0-tilstanden og samtidig reduksjon av det forurensende material til lavere aksydasjohs-tilstander.eller endog til metallisk tilstand. Hvis f.eks» et ;ion av et. flerverdig metall hører til <>n anionisk gruppe, forer;. fremgangsmåten til dannelse av et salt av det samme metall i.en lavere valenstilstandj- som lett kan fjernes ved kjent teknikk. ;I motsetning til dette, hvis vannet inneholder et edelmetallsalt frembringer fremgangsmåten det tilsvarende metall. ;Følgelig reduseres kromater til troverdige kromsalter,. og kobber-eller kvikksølvsalter reduseres til henhv. metallisk kobber eller kvikksølv. ' De reaksjoner som foregår i noen av de ovennevnte tilfeller kan gjengis Ved de følgende reaksjonsskjemaer, hvori Fe anvendes som elektropositivt element: ; for kromater, mens reaksjonsskjemaet for edelmetaller blir nFe + 2 Me<n+>«*n Fe<2+>+ 2 Me of waste water containing chromium, mercury and other ferrous metal compounds, and the distinctive feature of the method according to the invention is that the waste water is brought into contact with an element selected from those elements which are less noble than hydrogen*; it is known from scientific publications that a method has been proposed for the reduction of Cr<+>^ to Cr<+>^ where metallic iron is used. However, this method has not found industrial application to a great extent, above all because of the high consumption of iron, which leads to large quantities of sludge that must be removed and a consumption of precipitation mite! (CatOH^ or NaOH) higher than those occurring in the usual processes (SO^ and bisulphite); On the other hand, it is clear that if the reaction took place with an Fe-f or use corresponding to the theoretical, the process would be advantageous from an economic point of view. It has now been found that if the pH of the solution to be treated and the lower rate thereof in the reducing system are appropriately regulated, it is possible to carry out the process with an iron consumption very close to the theoretical value without simultaneous occurrence of passivation phenomena for the metal, since these phenomena are due to the formation of a passivated film on the metal surface which completely deactivates the metal over a period of time. If the pH in the effluent from the reducing system is kept below the value at which Fe is precipitated as hydroxide, these phenomena are completely avoided. More specifically, the process according to the invention is carried out by allowing the water to be treated to flow through one or more columns filled with the element that is less noble than hydrogen, the element being in the form of grains, spheres, small rods, shavings. or any shape that can be adapted to the size of the columns themselves. The reaction that takes place when the water flows through the columns consists in oxidation of the element in the 0 state and at the same time reduction of the polluting material to lower oxidasjohs states.or even to the metallic state. If, for example, an ion of an polyvalent metal belongs <>n anionic group, forer;. the method for forming a salt of the same metal in a lower valence state which can be easily removed by known techniques. In contrast, if the water contains a noble metal salt, the method produces the corresponding metal. Consequently, chromates are reduced to reliable chromium salts. and copper or mercury salts are reduced to metallic copper or mercury. The reactions that take place in some of the above cases can be reproduced by the following reaction schemes, in which Fe is used as an electropositive element: ; for chromates, while the reaction scheme for noble metals becomes nFe + 2 Me<n+>«*n Fe<2+>+ 2 Me

'." Me er her edelmetallet, f .eks. som nevnt kobber eller kvikksøl?/, og n er oksydasjonstilstanden av dette. '." Me is here the noble metal, e.g. as mentioned copper or mercury?/, and n is the oxidation state of this.

Reaksjonen foregår uten noen energitilførsel utenfra, ved pH lavere eller lik 3. The reaction takes place without any external energy supply, at a pH lower than or equal to 3.

Renseprosessen i henhold til den foreliggende oppfinnelse kan gjennomføres ved en hoy gjennomstrømning, og et spesielt og fordelaktig trekk ved fremgangsmåten i henhold til oppfinnelsen består i>å arbeide ved de høyest mulige gjennomstrømninger i avhengighet av pH og konsentrasjonen av det forurensende material. Med dq samme mengder av redusert forurensende material vil økning av gjennomstrømningen føre til at forbruket, .av det elektropositive element nærmer seg sterkt den teoretiske verdi0 The cleaning process according to the present invention can be carried out at a high flow rate, and a special and advantageous feature of the method according to the invention consists in working at the highest possible flow rates depending on the pH and the concentration of the polluting material. With the same amount of reduced polluting material, an increase in the flow will cause the consumption of the electropositive element to approach strongly the theoretical value0

Oppfinnelsen vil lettere bli foc±ått ved hjelp av de følgende eksemi„élvise utf ørelsesf ormer. The invention will be more easily understood by means of the following exemplary embodiments.

EKSEMPEL 1 EXAMPLE 1

pH-innvirkningpH impact

En kolonne med diameter .2.7 cm ble fylt med sylindriske korn avA column of diameter .2.7 cm was filled with cylindrical grains of

Fe (<7 = 4 mm, høyde «= 6 mm), og oppløsninger inneholdende Cr^<+>ble sendt gjennom kolonnen ved forskjellige pH-verdier. Fe (<7 = 4 mm, height «= 6 mm), and solutions containing Cr^<+> were passed through the column at different pH values.

Alle prøver ble gjennomført ved konstant gjennorns tr on Ci ing ogAll tests were carried out at constant gjennorn's tr on Ci ing and

de oppnådde resultater er oppført i tabell 1. the results obtained are listed in table 1.

EKSEMPEL"- 2EXAMPLE" - 2

Innvirkning av gjennomstrømningen (volumhastigheten).Impact of the flow rate (volume rate).

Det ble gjennomført noen forsøk i samme kolonne.som i det foregående eksempel ved anvendelse av det samme fyllevolum, mens pH ble holdt konstant og gjennomstrømningen ble endret. Some experiments were carried out in the same column as in the previous example using the same loading volume, while the pH was kept constant and the flow rate was changed.

Resultatene er oppført.i tabell 2.The results are listed in Table 2.

EKSEMPEL 3 EXAMPLE 3

Innvirkning av lineær strømhingshastighet. Effect of linear current slew rate.

320 cm 3 Fe ble i rekkefølge innført i tre kolonner med.forskjellige diametre og en oppløsning inneholdende Cr 6+ ble. sendt derigjennom ved konstant volumhastighet og pH slik at den samme kontakt-tid 320 cm 3 Fe was successively introduced into three columns with different diameters and a solution containing Cr 6+ was. sent through it at constant volume rate and pH so that the same contact time

mellom oppløsning og fyllgods ble oppnådd med forskjellige lineære hastigheter <» between solution and filler was achieved with different linear velocities <»

Resultatene er oppført i tabell 3.The results are listed in Table 3.

EKSEMPEL 4 EXAMPLE 4

Innvirkning av kolonnediameteren. Influence of the column diameter.

Det ble anvendt kolonner med forskjellige diametre, Det var mulig å påvise, som vist i tabell 4, under den samme tilførselsstrøm, at 6+ Columns with different diameters were used. It was possible to demonstrate, as shown in Table 4, under the same feed flow, that 6+

den mengde Fe som var nødvendig for total reduksjon av Cr til Cr^+ nedsettes ved nedsettelse av diameteren av selve kolonnen. the amount of Fe that was necessary for total reduction of Cr to Cr^+ is reduced by reducing the diameter of the column itself.

Claims (5)

1. Fremgangsmåte for frensing av spillvann som inneholder tung-metall forbindelser } k a'r a k t e r i s e r. t ved at spillvannet bringes i kontakt, med et element valgt fra llassen av Elementer som.er mindre edle enn hydrogen.1. Process for purifying waste water containing heavy-metal compounds, characterized in that the waste water is brought into contact with an element selected from the list of elements which are less noble than hydrogen. 2. Fremgangsmåte som angitt i krav 1, karakterisert ved at vannet som skal behandles sendes gjennom en eller flere kolonner fylt med elementet som er mindre edelt enn hydrogen i form av korn,.kuler, små stenger, .. spon eller' annen form som egner seg for bruk med størrelsen,av selve kolonnen. 2. Method as stated in claim 1, characterized in that the water to be treated is sent through one or more columns filled with the element that is less noble than hydrogen in the form of grains, spheres, small rods, .. shavings or other form suitable for use with the size of the column itself. 3. Fremgangsmåte som angitt i krav 1 eller 2, karakterisert ved at reaksjonen foregår ved pH lavere eller lik 3. v 3. Method as stated in claim 1 or 2, characterized in that the reaction takes place at a pH lower than or equal to 3. v 4. Framgangsmåte som angitt i krav 1-3, karakterisert ved at vannet som behandles inneholder kromater og at det anvendte element er jern. 4. Procedure as specified in requirements 1-3, characterized in that the treated water contains chromates and that the element used is iron. 5. Fremgangsmåte som angitt i krav 1-4, karakterisert ved at pH i.utløpet fra det reduserende systera holdes under den verdi ved hvilken Fe felles.ut . som hydroksyd...5. Procedure as stated in claims 1-4, characterized in that the pH in the outlet from the reducing system is kept below the value at which Fe falls out . as hydroxide...
NO751626A 1974-05-08 1975-05-06 NO751626L (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT22396/74A IT1010486B (en) 1974-05-08 1974-05-08 PROCEDURE FOR THE PURIFICATION OF WASTE WATER

Publications (1)

Publication Number Publication Date
NO751626L true NO751626L (en) 1975-11-11

Family

ID=11195718

Family Applications (1)

Application Number Title Priority Date Filing Date
NO751626A NO751626L (en) 1974-05-08 1975-05-06

Country Status (23)

Country Link
JP (1) JPS50152557A (en)
AT (2) AT346253B (en)
BE (1) BE828570A (en)
CH (1) CH617642A5 (en)
CS (1) CS202546B2 (en)
DD (1) DD118051A5 (en)
DE (1) DE2520531A1 (en)
DK (1) DK196775A (en)
ES (1) ES437875A1 (en)
FI (1) FI751142A7 (en)
FR (1) FR2270209B1 (en)
GB (1) GB1474145A (en)
IE (1) IE41336B1 (en)
IL (1) IL47073A (en)
IT (1) IT1010486B (en)
LU (1) LU72427A1 (en)
NL (1) NL7505514A (en)
NO (1) NO751626L (en)
PL (1) PL111038B1 (en)
RO (1) RO69366A (en)
SE (1) SE7505290L (en)
TR (1) TR19213A (en)
YU (1) YU103975A (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2613128C2 (en) * 1976-03-27 1982-03-04 Hoechst Ag, 6000 Frankfurt Process for reducing the mercury content of industrial wastewater
IT8348501A0 (en) * 1982-06-16 1983-06-14 Occidental Chem Co APPARATUS AND PROCEDURE FOR REMOVING COPPER IONS FROM AN AQUEOUS SOLUTION
DE3411228C1 (en) * 1984-03-27 1985-05-30 Du Pont de Nemours (Deutschland) GmbH, 4000 Düsseldorf Process for the environmentally friendly purification of photographic wash water from film processing machines and apparatus for carrying out the process
DE4217987A1 (en) * 1992-05-30 1993-12-02 Battelle Institut E V Removal and recovery of heavy metals from earth, sludges and waterways - by amalgamation and sedimentation of esp. mercury@, nickel@ and cobalt@ and their cpds., by addn. of powered zinc@ or aluminium@
DK0660804T3 (en) * 1992-09-18 1997-09-01 Krueger As I Process for purifying metal-containing aqueous media and process for preparing an adsorbent.
DE102007045337B4 (en) * 2007-09-22 2021-01-07 Bayerische Motoren Werke Aktiengesellschaft Procedure for protection against dust containing chromium (VI)

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2177656B1 (en) * 1972-03-31 1979-02-16 Lewandowski Raymond

Also Published As

Publication number Publication date
FR2270209B1 (en) 1980-04-18
AU8013875A (en) 1976-10-21
PL111038B1 (en) 1980-08-30
GB1474145A (en) 1977-05-18
IE41336L (en) 1975-11-08
CH617642A5 (en) 1980-06-13
DK196775A (en) 1975-11-09
ATA390876A (en) 1979-01-15
AT346253B (en) 1978-11-10
DE2520531A1 (en) 1975-11-13
AT351775B (en) 1978-02-15
NL7505514A (en) 1975-11-11
RO69366A (en) 1981-07-30
CS202546B2 (en) 1981-01-30
ES437875A1 (en) 1977-01-01
FR2270209A1 (en) 1975-12-05
IL47073A0 (en) 1975-06-25
YU103975A (en) 1982-02-28
BE828570A (en) 1975-08-18
TR19213A (en) 1978-06-07
LU72427A1 (en) 1975-08-26
SE7505290L (en) 1975-11-10
DD118051A5 (en) 1976-02-12
IE41336B1 (en) 1979-12-05
ATA351775A (en) 1978-02-15
JPS50152557A (en) 1975-12-08
IL47073A (en) 1978-07-31
IT1010486B (en) 1977-01-10
FI751142A7 (en) 1975-11-09

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