DE1517458A1 - Process for the fine purification of natural waters that are contaminated by mineral oil products - Google Patents

Description

New documents , _. ", _ _Λ

P 15 17 458.0 Frankfurt (Main), June 11, 1968

DrEu / GKa

Process for the painful purification of natural waters that are contaminated by mineral oil products

The increasing use of heating oil and fuels has recently led to repeated contamination of water, the z. B. caused by unintentional penetration of mineral oils or mineral oil derivatives into the groundwater. It is known that such contaminated water can be purified by treatment with activated carbon. The economy this process depends on the amount of activated carbon that has to be adsorbed, since this requires the use of activated carbon will. The mechanically separable portions are expedient the impurities beforehand by filtration or precipitation with flocculants or combinations of these measures, from the Remove water, so that the activated carbon remains mainly the task of real or colloidally dissolved impurities from the To remove water adsorptively. It is also known to determine the content of mineral oil components in water reduce intensive ventilation. In doing so, the volatile mineral oil components are preferably expelled. These However, known methods of water treatment are not sufficient either by themselves or because of the considerable amount of resources required in any combination for the production of hygienically perfect drinking water from groundwater that contains mineral oils came into contact.

From the German patent specification 134 417 is a method for Degreasing of condensation wastewater is known in which oil or fat is present in the form of an emulsion. The cleaning takes place by treating the emulsion with strong oxidizing agents such as potassium permanganate or potassium dichromate. Potassium is preferred permanganate applied in neutral or alkaline solution. Brownstone and salts of carboxylic acids and are formed during the reaction the oxalic acid, the flocculated manganese dioxide is filtered off.

909824/107 2

From the Swiss patent specification 126 829 it is known to use a germ-containing water for the purpose of sterilization chlorine, hypochlorite or add chlorinated lime and then filter through decolorizing charcoal. To safely kill the germs, the application An excess of disinfectant is required, which affects the smell and taste of the water. That treated Water is therefore filtered through carbon, whereby the chlorine or hypochlorite contained in the water is converted into chloride ions will. The type of carbon used must be catalytically but not adsorbent.

The known processes give the person skilled in the art no indications as to how clear waters contaminated with mineral oil, i. H. Water, the mineral oils and / or contain mineral oil derivatives in real solution, can be finely cleaned in a simple and economical manner.

The invention consists in the use of the method known for sterilizing water, in which the water is mixed with chlorine is filtered through carbon, for the fine cleaning of natural substances contaminated by mineral oil products or similar substances Waters that have been pre-cleaned by aeration and / or flocculation and by mechanical filtration, whereby the water mixed with chlorine is then treated with activated carbon. In the method according to the invention, the water can instead chlorine mixed with chlorine dioxide or ozone.

According to the method of the invention, real dissolved mineral oil components are obtained or mineral oil derivatives and the lack of unpleasant smell and taste caused by them Water obtained by treatment with precipitants such as aluminum sulfate or the like and / or mechanical filtration over Sand filters have been pre-cleaned, and such waters are eliminated Made hygienically perfect by adding chlorine, chlorine dioxide or ozone to the water to be cleaned and then adding activated carbon to the water after a certain exposure time treated.

For the practical implementation of the method according to the invention, all known methods, such as aeration, Use of flocculants, mechanical filtration or the like, are suitable. For treatment with activated charcoal Powdered and / or granular activated carbons can be used.

90982 / f / 1072, - 3 -

The chlorine, chlorine dioxide or ozone is preferably added to the water before the treatment with activated charcoal Chlorine, chlorine dioxide or ozone have a certain exposure time of z. B. should have ten minutes.

Palis in the pretreatment of water substances in solid form, z. B. iron oxide hydrate are excreted, these can in a known manner by means of mechanical filtration through gravel filters or other filter materials are removed prior to the actual adsorptive activated carbon treatment. In this EaIl the introduction of chlorine, chlorine dioxide or ozone takes place before mechanical filtration, e.g. B. before the last mechanical Filter. It is advisable to simulate those produced during the treatment of mechanically pre-cleaned water with chlorine, chlorine dioxide or ozone However, solids are trapped in the top layer of the activated carbon filter and removed from this by temporary backwashing removed again. In this case it is advisable to subdivide the '' activated carbon layer so that the upper layer can be used for / can be backwashed. Therefore, plants for carrying out the process according to the invention contain in the last stage if necessary a two-layer filter with two backwashable activated carbon layers.

It depends on the individual case of the contamination of a groundwater with mineral oil or mineral oil products, whether this is caused by treatment With chlorine, chlorine dioxide or ozone in the pre-clarified water formed reaction products of the activated carbon with simple Agents can be desorbed again, e.g. B. by backwashing with cold or hot water or by steaming out, with in In all cases, air can also be introduced as an alternative.

The invention will be explained in more detail using an example: Example

Groundwater heavily contaminated with mineral oil components was first aerated, passed through a gravel filter to remove any precipitated turbidity and then treated with activated carbon. To remove the extremely unpleasant smell and taste of the water, which was clearly caused by mineral oil constituents, an amount of 500 g / m ^{5 of} activated carbon was necessary.

909824/1072

Was given a lot of the water before the treatment with activated charcoal of 5 g of chlorine / m were added, only 80 g of activated carbon / m were left required to achieve the same good effect as was achieved in the experiment without chlorine, but with 300 g activated carbon / m ^.

5 g chlorine / m is therefore sufficient to absorb more than 200 g activated carbon / no to save, so that the activated carbon requirement fell to less than 1/3 of the original.

The amounts of activated carbon and chlorine mentioned in the above example can of course also be subject to considerable changes in the case of a different degree of contamination. So z. B. with relatively low impurities without the use of chlorine already activated carbon quantities of 40 g / m ⁵ , with the use of z. B. 2 g chlorine / nr 12 g activated carbon / m 'are sufficient.

90982 /, / 1072

Claims (2)

New patent claims 1) Use of a known method for sterilizing water Process in which the water is mixed with chlorine and then filtered through carbon for painful purification natural water contaminated by mineral oil products or similar substances, caused by aeration and / or flocculation and are pre-cleaned by mechanical filtration, the water mixed with chlorine then being coated with activated carbon is treated. 2) Method according to claim 1, characterized in that the water is mixed with chlorine dioxide or ozone instead of chlorine will. 909624/1072 Documents (Art 7, Paragraph 1, Paragraph 2, No. I, Sentence 1 of the Amendment Act of September 4, 1987)