DE2044769A1 - Process for obtaining germ-free drinking water from surface water and device for carrying out the process - Google Patents

Description

The invention relates to a method for obtaining aseptic drinking water from surface water, wherein in a first process step in the cloudy water by high chlorine addition a fast bacteria and germ killing takes place, in a second process step the colloidal turbidity of the cloudy water is eliminated are, in a third process step, the clear filtration of the irübwassers takes place, and in the fourth and in the last process stage, dechlorination is carried out by means of activated carbon.

209812/0647

- 1a -

The invention further relates to a device in the form of a small filter for carrying out the method to be proposed according to the invention.

Surface water from lakes, rivers or pools of water is always more or less cloudy and contaminated with bacteria throughout. The treatment of such waters requires manifold, professionally controlled procedures that were previously carried out in large filter systems. The treatment of the smallest amounts of water of this kind and their conversion to drinking water is a very difficult one Problem that has not yet been solved in a satisfactory manner.

At the same time, there would be the existence of a simple and safe process for cleaning small amounts of turbid water and a corresponding small water filter

209812/0647

for many uses and especially desirable in emergencies «

The treatment of surface water in large waterworks has so far been carried out e.g. in the following procedural operations:

In the first stage, the cloudy raw water is disinfected with active chlorine (usually gaseous Chlorine) mixed. In practice one works with a higher addition of chlorine (so-called I.

High chlorination) than would be necessary to ensure a rapid and complete destruction of all Reach bacteria and germs.

The second step concerns the elimination of the colloidal parts of the cloudy water Precipitation e.g. with aluminum sulfate as a precipitant

- as a third stage of work - in the settling basin M

divorced.

The raw water pretreated in this way is then filtered through a gravel filter in a fourth stage the clear filtrate finally in the fifth and last stage over high, with activated charcoal gravel filled filter columns to remove the "excess" chlorine still present in the clear water remove. Because it has to be for drinking water purposes

_{27 / 7o} 209812/0647

9/8/70 - 3 -

The filtrate obtained must be free of chlorine.

It is obvious that the cleaning of the smallest amounts of water is not after this cumbersome and agile Process can only be carried out in an approximately similar manner, because one is to be created for this purpose Device must work very easily and be easy to use by laypeople.

A particularly aggravating circumstance for the development of a small filter is the fact that for the Dechlorination required activated charcoal filter bed after temporarily unused and still wet condition as so-called germ breeder proves; i.e., an already sterile prefiltrate is released as it passes through this carbon filter bed again contaminated with bacteria. As a result, such a filter bed must be installed before each new filtration to be started, e.g. are laboriously sterilized by introducing superheated steam. Since small filters are only used temporarily, the use of a filter bed with activated carbon grit for dechlorinating a small amount of water is excluded. Because a sterilization poration is neither feasible nor reasonable for laypeople.

The object of the invention is to create a method in which the above as necessary for the large-scale process five work operations described are modified in such a way that

2 _{7 /? 0} 209812/0647

- * ■ - 20U769

that a cleaning of the smallest amounts of surface water in a simple device; is possible, and yet one for Filtrate suitable for drinking water purposes is supplied.

In the further embodiment of the invention, a device is to be shown that enables the implementation of the method according to the invention made possible in a simple manner, and in particular also the handling by the layperson without much guidance and attention.

The invention proposes to solve the problem first of all a method which is characterized in that the dechlorination in the production of small amounts of drinking water of the cloudy water over-chlorinated with a chlorine salt, e.g. calcium hypochlorite, in the last process stage takes place by means of a thin carbon membrane, which is made of pulp interspersed with activated carbon powder} such carbon membranes can be produced by pressing.

The starting point for this solution was the knowledge that the dechlorination of a chlorinated raw water can be carried out sufficiently effectively with a thin cellulose membrane, which contains approx. 50% activated carbon powder, instead of a voluminous activated carbon filter bed.

8.9.70 ~ 5 -

209812/0647

In the process according to the invention, if the cloudy water that was overchlorinated in the first process stage is poured onto a activated charcoal powder approx single pass and with sufficient passage -

speed of e.g. 1o - 15 1 / dm / h the content of free chlorine of usually 2 mg / 1 is spontaneously reduced to a residue of less than 0.2 mg / 1 by conversion; this slight residue is no longer noticeable in terms of taste in drinking water.

This surprisingly strong dechlorination effect even makes it possible, with an even higher chlorine excess than usual, e.g. to work with 3-4 mg / 1, which results in an almost sudden destruction of all germs takes place.

The fast and extensive dechlorination effect for highly chlorinated turbid water when using a carbon membrane could not be foreseen, as in large-scale systems, in practice, the water to be dechlorinated was provided with activated charcoal and also considered necessary.

In contrast to this, now takes place - as was stated when using the proposed, thin carbon powder-cellulose membrane an almost complete breakdown of the free chlorine at the moment. This effect alone

9/8/70 - 6 -

209812/0647

204,769

allows the use of a thin one in the first place Membrane made of carbon powder and cellulose for dechlorination purposes in the manner proposed.

However, the duration of the effect of the carbon membrane is limited to a smaller amount of filtrate, because the duration of action the dechlorination depends on the amount of activated carbon powder built into the membrane.

If you now adjust the duration of the membrane's action (e.g. from Ä

1 dm surface) to a filter period of e.g. approx. 1o liter, which is appropriate for a small filter to be proposed one, so it is necessary to use a fresh membrane for each new filter period. But at the same time prevents the serious risk of germ contamination of the dechlorination filter in a simple manner, because with a freshly inserted, dry carbon membrane in a dry filter device one obtains - like experiments show - each time a new filtration is started, there is always a germ-free filtrate.

In the further embodiment of the invention, it is proposed in a second method step that Membrane consisting of cellulose and activated carbon powder also acts as a carrier membrane for an additional, increasingly to use a filter layer that builds up with the passage of the cloudy water. To build

27/70 209812/0647

9/8/70 - 7 -

20U769

to bring about such an additional filter layer, an appropriate filter aid should be added to the cloudy water at the same time as the chlorine salt is added will. These are in particular colloid-binding components of the filter aid such as e.g. Asbestos fibers, talc, etc., which are added to the raw water and intimately mixed with the raw water. This will achieves that the difficult-to-filter colloidal turbidity fractions agglomerate with the substances mentioned and thus can be made filterable. In addition, the filter aid should contain a component that the additional Keeps the filter layer porous and loose, in particular diatomaceous earth.

The turbid water prepared in this way is placed in a filter vessel on the bottom of which the carbon membrane is located is located, the carbon membrane itself will act as a filtering layer at the beginning of the filtering process, however, immediately after the start of the filtration, the added filter aid settles out of the cloudy water on the membrane and forms a new, initially thin, but increasingly thicker filter layer. This loose The deposited filter layer is a mixture of coarse and fine-grained filter aid, mixed with all of the Suspended solids originating from turbid water and the colloidal turbid parts that have since bound. Such a mixture-substance structure the new filter layer continues until the end of the filter period. This shift now takes over

209812/0647 27/70
9/8/70 - 8 -

completely the task of clear filtration of the sludge, so that the carbon membrane only has a clear filtrate for Entohlorung is fed.

A two-component filter with a clear separation of tasks is created automatically and increasingly: filtering out the bound colloidal turbidity and all suspended matter on the one hand and dechlorination on the other. Through this this prevents turbid particles from getting on and into the carbon membrane which otherwise clog the fine pores of the membrane and the activity of the carbon powder quickly were diminishing. The filter effect would come to an inadmissible early standstill; on the other hand, it remains new The filter layer that forms for the clear filtration is loose and therefore porous, which not only enables rapid filtration possible, but also guarantees a long filter throughput time is.

According to the invention, the procedure is summarized in the following way: In a similar way, from a large-scale operation known method takes place in a first process step quick killing of germs and bacteria through the addition of chlorine in a small amount of cloudy water; In a second process step, the colloidal components of the water become cloudy eliminated by agglomeration instead of precipitation; in The third stage of the process is clear filtration and finally in the fourth stage the dechlorination by means of

Activated carbon. 209812/0647

9/8/70 - 9 -

Process steps 2 to 4 are combined in a single filter pass.

In commercial filter practice, it is known per se in so-called precoat filters to have a filter that is to be filtered Also add cloudy filter aids such as diatomaceous earth, fibrous material, etc. and these substances then also affect one also to allow the previously washed-up layer of kieselguhr etc. to settle. The procedure has only the purpose of »the filter throughput time of the precoat layer extend, but not achieve the creation of an independently effective filter layer.

In the method according to the invention, however, it is important to ensure that the function of a clear filtration of the carrier layer, namely to avert the dechlorination membrane at all and this task exclusively from the filter aid to transfer newly forming filter layer. With this filter technology the clarification of the Cloudy reached before entering the carbon membrane and, what is essential, in a single filtration cycle.

The very cumbersome and time-consuming process that is common in large-scale proceedings Precipitation of the colloids is replaced here by the binding of these turbidity components to filfcerhiifssfcoffe and whose. Filtration on the TQ arfiltratlonsschicht.

27 / 7P 20S812 / 0647

8.9.?o - 1o -

* mm

JH

Only the measure according to the invention, namely the three Process stages colloid skimming, clarification and filtration Dechlorination can be carried out in separate operations, but in a single piltration process and then to obtain aseptic and clear drinking water as well, makes this process and its facility In a small filter that is easy to operate by the layman and that works without pressure, it becomes practical in the first place usable device.

In the further embodiment of the invention, a small filter is used as the device for carrying out the method suggested. This is explained below with reference to the drawing.

Show in the drawing

1 shows a filter constructed for filtration

according to the invention in the central longitudinal section and ™

in a schematic representation

and

FIG. 2 shows the device according to FIG. 1 in its assembled state for transport.

The device consists of serving as percolating ¹ FII teroberteil 1 and the slightly less large, serving as Auffangbuhälter filter base 2 made of transparent

Material. Preferably parts 1 and 2 are made of plastic _{2? / 7o} 209812/0647

8.9.7ο - 11 -

manufactured. Both filter parts have a circular cross-section. The filter vessel 1 is open at the top and with the bottom a bottom 3 closed. Accordingly, the receptacle 2 is open at the top and closed with a bottom 4 ·. In the state of use (Fig.1), the two parts are coaxial arranged one above the other, and the filter vessel 1 sits loosely, but radially fixed, while maintaining an air gap, on the receptacle; this is achieved through a annular overhang 5 on the upper part of the filter. In the middle is the bottom 3 of the filter part 1 is provided with an outlet opening 8. The bottom 3 and the ribs 6 are arranged so that the filtrate can flow to the outlet opening 8. The carbon membrane 9 is loosely placed on the collar 7 and the ribs 6. As described above, this filter membrane consists of a cellulose fabric, in particular cellulose cardboard, which is interspersed with about 50% activated carbon powder.

The upper filter vessel 1 is used to receive the cloudy water, while the collecting container 2 to receive the filtered Water is intended.

The outer dimensions of the collecting container 2 are smaller than the inner dimensions of the filter vessel 1, so that for the transport of the filter of the collecting container 2 can be placed in the filtering vessel 1 (Fig. 2). For transport an insert 1o is also provided in the collecting container 2, in which a storage bottle 11 for the

209812/0647 _ ₁₂ _

Recording of the chlorinated filter aid and a measuring spoon 12 are inserted. At the top is the filter vessel 1 can be closed with a lid 13. This lid is as a flat box with a lower part 13 a and a cover 13 b formed. The carbon membranes 14 in stock are housed in this lidded box.

To carry out a filter operation, the cloudy water is first mixed with, for example, 3 measuring spoons 12 of the chlorine-containing filter aid from the bottle 11 outside the small filter, for example in a bucket of approx. 10 liters, and stirred well. After a few minutes, which can each * ² * bacteria-free clear water be filled with the bound through the filter aid colloidal and other suspended solids in the percolating 1 already after loosing a carbon membrane 9 was inserted from the Torratsdose 13 in the filtration vessel. A special sealing of the membrane 9 on the collar 7 of the filter vessel is not required, since the pressure of the water column above ensures the necessary seal. The bacteria-free, but still cloudy water passes through the membrane 9, which initially takes over the clarification and dechlorination. Immediately after the start of the filtering process, however, the filter aid, i.e. kieselguhr, asbestos fiber, talc, etc., and the suspended matter settle as an additional filter layer 15 on the top of the carbon membrane 9. From this point on there is a clear separation of duties in such a way that the new ones

27/70 209812/0647

8.9.7ο - 13 -

increasingly forming filter layer 15 absorbs all suspended matter and bound colloid fractions, while the underlying membrane 9 the clear filtrate passing through dechlorinated.

The filtrate obtained in the collecting container proves to be immediately - i.e. without a preliminary run - clear, germ-free and Tasteless and odorless drinking water that can be enjoyed without further ado.

By means of a scoop, water is continuously poured into the water until the prepared turbid water is exhausted poured the filter top 1, while the collecting beaker must be emptied more often into another vessel.

When the filtration is complete, the filter membrane and the substances deposited on it are removed from the filter vessel removed. After cleaning and drying the filter vessel, a new filtration can be started.

The whole treatment of small amounts of surface water, according to the invention, consists only of what is brought about To add a few measuring spoons of filter powder to the cloudy water, to see and then in one Filter operations.

209812/0647

Claims (8)

Munich October 6, 1970 w / wt claim 3 method according to claims 1 and 2, characterized in that at the beginning of the filtration the membrane is placed in a dry state in a dry vessel for carrying out the method. 209812/0647 Applicant: Representative: 204 Ewald Zdansky Patentanwalt Helmut Walter ffl-94-90 Vaduz 8 Munich - 6ot Pradafant 642 Aublnger Str. 81 Munich, Sept. 8th 197o wt / schm claims 1. Process for obtaining aseptic drinking water from Surface water, with a first step in the turbid water due to the high addition of chlorine fast bacteria and egg killing takes place, in a second process step the colloidal turbid substances of the turbid water are removed, in a third process the IQ.arfiltra.tion of the turbid water takes place, and in the fourth and last stage of the process, a dechlorination is carried out using activated carbon is, characterized in that the dechlorination of the with a small amount of drinking water Chlorine salt over-chlorinated cloudy water takes place in the last process step through a thin carbon membrane, which consists of pulp interspersed with activated carbon powder. 2. The method according to claim 1, characterized (characterized in that the carbon membrane consists of about ^! Po% activated carbon powder and about 5o % pulp. 7/70 9812/0647 _ * ._ 20U769 -fr 3. The method according to claims 1 and 2, characterized in that the carbon membrane as a carrier membrane acts for an additional filter layer which is used for clearing filtration after the start of the filtration "When the cloudy water mixed with the filter aid passes through, it appears on the carbon membrane the filter aid forms anew with the inclusion of suspended matter, the filter aid in the cloudy water serves to bind the colloidal turbidity. ™ 4-. Process according to Claims 1 to 3> characterized in that that the filter aid contains, in addition to components for colloid binding, other components that Keep the additional filter layer loose and porous, especially kieselguhr. 5. The method according to claims 1 to 4, characterized in that the cloudy water before its filtration A filter powder is added, which is composed of chlorine salt and filter aid. 6. The method according to claims 1 to 5 »characterized in that that the filter aid is preferably asbestos fiber and talc as colloid-binding constituents contains. 7. The method according to claims 1 to 6, characterized in that the binding of the colloidal turbid substances _{27 / 7o} '2 09812/0647 8.9.7ο - 3 - to the filter aid, the clarification of the cloudy water before the dechlorination and the de-chlorination takes place over the carbon membrane in a single filtration pass. 3, device for carrying out the method according to one of claims 1 to 7 »characterized in that two approximately equal-volume filter parts (-Ij2) are arranged one above the other, of which the upper filter part (1) serves as a filter vessel for receiving the turbid water, the uneven filter part ( 2) as a collecting vessel of the recording, the filtrate is _s and that the two filter parts are connected together by a central outlet opening (8), and that the carbon membrane (9) is arranged above the outlet point in the percolating cup. 9. Apparatus according to claim 8, characterized in that the filter vessel (1) one of the outlet opening (8) perforated bottom (3) has »which by radial ribs (6) on the upper side and an annular one Bund (?) - is reinforced at the edge, with the ribs and the bundle loosely but dense recording of the carbon membrane to serve, lo »Device according to claims 8 to 9, characterized in that that the fiber vessel (1) is somewhat larger 27/70 8.9.7ο - 4- - 203812/064? Has internal dimensions than the collecting vessel (2) External dimensions so that the filter parts (1,2) can be plugged into one another when not in use. 11. Device according to claims 8 to 1o, characterized in that the filter vessel (1) with a Lid (13) can be closed, which in turn acts as a container for holding available carbon membranes (14) serves. 27/70
8.9.70 209812/0647 . ^ί0 · ♦