Liquid purification or separation – Processes – Making an insoluble substance or accreting suspended...
Patent
1984-02-23
1984-12-04
Wyse, Thomas
Liquid purification or separation
Processes
Making an insoluble substance or accreting suspended...
210727, C02F 156
Patent
active
044863144
DESCRIPTION:
BRIEF SUMMARY
The invention concerns a process for the treatment of sewage using precipitants and flocculants.
Some industrial manufacturing sectors, such as the paper- and cardboard industry, as well as commercial laundries use large amounts of water which end up as sewage, partly laden with considerable portions of ingredients. From an ecological and economical viewpoint, the treatment of this sewage represents a problem of constantly increasing importance. In the sewage treatment generally used today, the cleaning of the sewage is effected in a combined precipitation and degradation process. The precipitation is effected by adding precipitants and flocculants to the sewage by which a major part of the ballast materials dissolved or dispersed in the water is transformed together with the precipitants and flocculants into an easily separable form, mostly into a non-slimy flocculant deposit. A number of precipitants and flocculants are described in the literature. In addition to organic polymeric compounds based on acrylamide, for example, lime, as well as hydrolyzing iron- and aluminum salts and silicates are described primarily as precipitants for cleaning sewage. Thus a water-treatment process is known from U.S. Pat. No. 2,310,009 where an aged, aqueous mixture of a sodium silicate solution and an aluminum sulfate solution is used as a precipitant.
German Pat. No. 971,180 described acid SiO.sub.2 -brines containing iron- or aluminum salts for the treatment of sewage. A similar process working with brines containing less SiO.sub.2 is described in British Pat. No. 827,586. U.S. Pat. No. 3,235,444 describes a process for the treatment of sewage from the manufacture of paper where the flocculation is effected by adding aluminum sulfate and activated silica to the sewage. Activated silica and aluminum sulfate for the treatment of highly contaminated sewage are also described in "Zellstoff und Papier" 13 (1964) p. 331 ff, where the activated silica is produced by the introduction of chlorine gas into waterglass solutions. These known treatment methods cannot be fully satisfactory, because they are not effective enough; besides, they require large amounts of precipitants, and the sludges obtained are voluminous and rich in water, which renders any possible after-treatment of the sludges and their deposit difficult.
The use of amorphous alkali-aluminosilicate dispersions, which are produced by mixing aqueous alkalisilicate- and aluminum salt solutions under vigorous shearing, is known from DE-OS No. 22 29 895 as the Norwich process. In this process the dispersions are used "in situ" for the precipitation of sewage ingredients, so that a plant for the production of these special dispersions must be operated in these sewage treatment plants. It is obvious that troubles can easily be caused by the necessary adaptation of these two plants to each other.
The object of the present invention was therefore to provide a simple process for the treatment of sewage, which is more effective and also supplies sludges that are easier to handle.
This problem is solved by the process according to the invention, which is characterized in that, in addition to the usual precipitants and flocculants, ab. 0.1-10 g per liter sewage of an X-ray amorphous or crystalline, finely divided alkali metal and/or alkaline earth metal alumosilicate containing preferably bound water, of the formula calcium, potassium or magnesium, and n equals 1 or 2, are added to the sewage to be treated, which has been adjusted, if necessary, to a weakly alkaline or weakly acid pH-value, and that the precipitate formed is separated from the water.
Suitable finely-divided alumosilicates contain practically no particles over 50.mu., preferably over 30.mu.. The particle size is generally between 0.1 and 10.mu..
Known precipitates are, e.g. aluminum- or iron sulfate and alkalisilicates which form voluminous deposits when added to sewage, on which sewage ingredients are adsorbed, which are removed from the sewage during the separation of the precipitates. By adding flocculants t
REFERENCES:
patent: 3300406 (1967-01-01), Pollio
patent: 3388060 (1968-06-01), Clark
patent: 3617561 (1971-11-01), Fanselow
patent: 3909406 (1975-09-01), Lang
patent: 3963640 (1976-06-01), Smith
patent: 4098714 (1978-07-01), Derleth et al.
Koppelmann Edgar
Krapp Gerd
Schumann Klaus
Smolka Heinz G.
Henkel Kommanditgesellschaft auf Aktien
Littell, Jr. Nelson
Szoke Ernest G.
Wyse Thomas
LandOfFree
Process for the handling of waste waters does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the handling of waste waters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the handling of waste waters will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1581227