SE536478C2 - Method and apparatus for handling wastewater - Google Patents

Abstract

Method for purifying sewage water from a first water closet (111), comprising the steps to: a) bring the sewage water from the first water closet to a locally arranged collecting container (121) for sewage water; b) allow the sewage water in the collecting container to evaporate and again condense on a condensing surface; c) collect the condensed water in a locally arranged storing container (123) for condensed water; d) use the condensed water for flushing in a second water closet, which may be the same as the first water closet; and e) from the collecting container remove the sludge which after said evaporation remains in the collecting container for further treatment; whereby when the amount of water in the collecting container exceeds a certain maximum amount, return the surplus amount of water to the collecting container. The invention also relates to a combination container.

Description

5,535,478 quantity. Thus. imbalances occur in the groundwater balance, with the risk of, for example, salt water intrusion and drainage of water wells. In addition, frequent sludge suction is required, which is costly.

Furthermore, it is often not advisable or permissible to use fresh water from watercourses or the sea for, for example, flushing a water toilet that is connected to an infiltration plant, as this can add unacceptably large amounts of nutrients and bacteria to the local environment at the property.

Furthermore, from the society's perspective, it is often desirable to collect the business and. the energy-bearing parts of the wastewater, such as biological material and nutrients, for return to the larger cycle. A conventional treatment step, such as a so-called mini treatment plant, often removes a certain part of this desirable material by, for example, oxidation of carbonaceous material, collecting certain chemicals such as phosphorus in filters and the like which must later be deposited, and so on. .

This means that these substances cannot be utilized optimally in the larger cycle.

The dry substance in wastewater from water toilets constitutes a valuable raw material for the production of, for example, biogas. As such, however, specific requirements are placed on, among other things, the degree of chemical contamination and the degree of dryness of the sewage sludge.

In addition, a conventional treatment step of the above-mentioned type is often, exorbitantly expensive, connected directly to the sewage line, which means that operational faults cause immediate cessation of the treatment function, which either leads to wastewater-producing equipment, such as a water toilet or a dishwasher, not being used. i. waiting for service technicians, 10, 25 30 30 536 478 or, which is worse, that the wastewater from such equipment flows straight through the failed purification stage and into nature without the user receiving immediate information about this. In addition, such a purification step typically also consumes environmentally harmful chemicals, which must be disposed of or released into nature.

Many conventional sewage management systems for use in non-municipal properties. sewers also set specific requirements for the type of wastewater-producing equipment that can be used in buildings, such as requirements for low-flush water toilets. This not only infringes on the freedom of the user, but also means that such systems are associated with increased installation costs.

The Swedish patent with number 531290 describes a procedure for maintaining the water balance in a property, where wastewater is removed and fresh water, for local storage, is returned in a corresponding amount. This procedure requires, in addition to frequent sludge suction, regular external refilling of fresh water.

The Swedish patent application not yet published at the time of the present invention with number 1100791-1 describes a method and a device for handling and purifying waste water from one or more water toilets, whereby the waste water is allowed to evaporate and condensation water is collected in a separate vessels for use as rinsing water.

Finally, for reasons of convenience, there is a need for portable toilet facilities, including water toilets, in places that do not have a municipal sewer or other permanent way of disposing of waste water from a toilet. This applies, for example, to festivals and other temporary events, construction sites, disaster sites and developing countries.

In conclusion, it is desirable to provide a method for managing wastewater from one or more water toilets which only minimally affects the local water cycle and is reliable, which requires a minimum of maintenance and sludge suction, which can collect the entire energy and nutrient-containing fraction and which is cheap both to install and to operate.

The present invention solves the problems described above.

Thus, the invention relates to a method for managing wastewater from a first water toilet, comprising the steps of: a) transporting the waste water from the first toilet to a locally arranged one. waste water collection containers; b) allowing the waste water in the collection container to evaporate and condense again on a condensing surface; C) collecting the thus condensed water in a locally arranged storage container for condensed water; d) use the condensed water for flushing in a second water toilet, which may be the same as the first water toilet; and removing from the collection container the sludge remaining after said evaporation in the collection container for further treatment, which method is characterized in that, when the amount of water in the storage container exceeds a certain maximum amount, the excess amount of water is returned to the collection container so that the dry matter content of the collection container is kept within a certain range.

The invention also relates to a system for managing waste water from a first water toilet, comprising means for conveying the waste water from the first toilet to a locally arranged collection container for waste water, arranged. receiving and accommodating a certain maximum amount of waste water, the system further comprising a storage container for condensed water, arranged to receive and accommodate a certain maximum amount of condensed water, the system further comprising means for supplying said condensed water to a second water toilet, which may be the same as the first water toilet, for use in flushing therein, which system is characterized in that the collection container and the storage container are both included in a combination container, which is associated with an upright operating orientation and which further comprises a condensing surface on which water evaporated from the collecting container can condense, because the combination container, when oriented in the operating orientation, is arranged to direct the water condensed on the condensing surface to the storage container by means of gravity, and, when the amount of water in the storage container exceeds the certain maximum amount k undensed water, return the excess to the collection container by overflow from the storage container, and by the combination container comprising a double-bottomed structure with an outer bottom and an inner bottom, where in the operating orientation the space between the outer and the inner bottom constitutes the storage container and the inner bottom form the bottom of the collection container.

The invention will now be described in detail, with reference to exemplary embodiments of the invention and the accompanying drawings, in which: Figure 1 is a schematic diagram illustrating an exemplary embodiment of the present invention. Figures 2a and 2b show the basic structure of a first exemplary combination container according to the invention. Figure 2b shows the container in figure 2a in cross section.

Figures 3a-3c show the basic structure of a second exemplary combination container according to the invention. Figure 3b shows the container, in figure 3a in cross section.

Figure 3c is a detail view of a part of figure 3b.

Figures 2a and 2b, 3a, 3b and 3c, respectively, share reference numerals for corresponding parts. Figures 2a-3c are partially exploded and simplified schematic diagrams.

Figure 1 shows a house 110 on the ground 115, in the form of a detached house or an apartment building. In the house 110 there is a toilet 111 permanently and permanently installed. It will be appreciated that the housing 110 may have more than one toilet 111 permanently and permanently installed, to which other toilets what is stated herein is correspondingly applicable. The toilet 111 is a water toilet, which is flushed with water. Preferably, the toilet 111 is not of the so-called ultra-low-flush type, i.e. the flush volume of the toilet is preferably at least 2 liters. Above all, it is preferred that the same toilet III as previously used in the property, also continues to be used as part of a facility according to the present invention after the facility in question has been installed. This means, for example, that the sealing layer in the wet room in which the toilet 111 is located does not have to be broken.

The wastewater is led from the toilet 111, via a drain pipe 124, to a local, ie. on the same property as, and preferably in the immediate vicinity of, the room in which the toilet 111 is installed, arranged a collection container 121 for wastewater. The collection container 121 preferably forms part of a combined. container 120 for wastewater and condensed water, see below. It is preferred that the effluent not be passed on from the collection container 121 to any extent, except that the water fraction be partially removed, as described below.

In addition, it is preferred that the remaining fraction, in other words the sludge remaining in the collection container 121, be emptied from time to time, when necessary when the volume of wastewater becomes too large or its dry content becomes too high, and / or at regular intervals. preferably by conventional sludge suction, for example by removing a lid 122 covering the container 121 so as to allow access to the container 121, and then removing the remaining fraction from the collection container 121 for further treatment. Such further treatment consists, for example, of digestion into biogas, and is preferably carried out at a central plant. Thus, it is preferred that the entire residue in the collection container 121, after the evaporation of water described below, be removed from the container 121 in this manner for central handling.

The collection container, 121 is arranged to store the waste water as a waste water volume 128 with an open surface 130.

Thus, the water contained in the wastewater will continuously proceed to the atmosphere arranged in the container 120. The evaporated water is recondensed on a condensing surface, which preferably comprises an inside of the container 120, i.e. the lid, among other things, on an inside of 122. In addition, of course, other surfaces which are in contact with the atmosphere above the liquid surface 130 are included, such as the upper portions of the inner side surfaces of the container 120 as illustrated in Figure 1.

From this condensing surface, the condensed liquid water is subsequently collected and taken to a condensed water storage container 123. The storage container 123 thus contains a volume of condensed water 129, which part may also comprise a proportion of fresh water which has not been supplied by condensation, see below. From there, the condensed water is then conveyed, via a line 125 and a pump 112, to a second water toilet, which may be the same as the first water toilet 111, and is used there for flushing in said second toilet. The pump 112 may also be located at other locations between the container 123 and the toilet, as submerged in the container 123. It is also noted that the figures show the first and the second water toilet both as the toilet III, but it will be appreciated that any number of water toilets may share the same treatment plant according to the present invention, and thus use the same collection container 121 etc. It is preferred that the storage container 123 constitutes the only source of flushing water for the second water toilet, preferably for all water toilets present installed in the same house 110 and preferably on the same property.

It is thus the sludge which after said evaporation remains in the collecting container 121 which is removed from the collecting container 121 for further treatment.

In order to increase the evaporation rate, it is preferable to have a device for supplying external heat energy, in order to be able to supply such energy to the collection container 121 if necessary. A preferred way of supplying such energy is by means of an electric immersion heater 117. however, it will be appreciated that other methods, such as a closed heat carrier circuit, where the heat carrier is heated by means of a heat exchanger connected to an external energy source (not shown), or directly by means of solar heat, may be used.

It is preferred that the said energy supply device is arranged to be switched on only in connection with an increased need for flushing water, such as when more people than those who normally live on the property in question are planned to be present. on the property for a limited period of time. It has been found that an externally supplied energy of as little as or equal to 1000 W, more preferably equal to or less than 500 W, more preferably equal to or less than 200 W, preferably equal to or less than 100 W, is sufficient to sufficiently increase the rate of evaporation to be able to cover temporary peaks in that the container 121, falls the flushing water requirement. It is preferred, or at least the container 120, is heat insulated in that external heat energy may be supplied. It is preferred that the co-energy is supplied at or adjacent to the surface, for example by the heating step 117 being in the form of a liquid heating coil, such as an electric resistance heater arranged to float on the surface 130, such as a heating cable arranged inside a water-filled tube of liquid plastic material.

This entails, among other things, reduced heat losses to the container 123.

When the amount of water in the condensed water storage container 123 exceeds a certain predetermined maximum amount, according to the invention, the excess amount is returned to the waste water collection container 121.

Thus, all contents of the containers 121, 123 will originate from the water toilet 111 and any other water toilets on the property. Since the flushing water in the toilet III consists entirely of evaporated and recondensed water, except for any initially supplied amount of fresh water (see below), no additional water is supplied to the containers 121, 123 through the flushing water. Instead, only the material, in the form of urine, is added in addition to 123 stools and. furthermore, the actual rinsing water to the containers 121, Since the rinsing water is recirculated in a cycle, the net contribution to the collection container 123 during continuous operation consists essentially only of this material. Depending on the rate of evaporation in combination with the rate of return of condensed water, a certain amount of rinsing water can also be supplied to the container 121.

Thus, after a continuous period of continuous operation, the dry matter content of the collection container 121 will generally be relatively low, and can also be controlled within a relatively narrow range. For example, the dry matter content can be kept at a level at least equivalent to that for wastewater, including flushing water, originating from a so-called ultra-low-flushing water toilet, which uses significantly less than 2 liters of flushing water per flush. This is seasonally less than 1 liter per flush. very desirable in digestion, as conventional treatment plants must otherwise perform. expensive evaporation of sewage sludge before digestion. Thus, the water content of the dewatered latrine in the collection container 121 can be regulated to create optimal conditions for energy and / or nutrient recovery in a central treatment plant.

At the same time, substantially all of the organic constituents will remain in the collection container 121, which is desirable prior to a later digestion or dehygienation step.

The amount of sludge present in the collection container 121 during sludge suction also becomes smaller; 50%, preferably the maximum, preferably a maximum of 30%, of the total amount of wastewater supplied from the water toilet, the flushing water is included.

This means that one and the same sludge suction truck can serve more properties than before, which leads to economic and environmental benefits. 15 25 30 535 478 ll Since the flushing water consists of recovered black water from the toilet lll, the local water balance is not charged, even though a conventional water toilet of a standard type is used.

The fact that no ultra-fast flushing toilet needs to be installed means not only increased use comfort, but also that existing waterproofing layers in the bathroom can be retained.

The latter, and the fact that an existing standard water toilet can be maintained during the installation of a system for carrying out a method according to the present invention, entails significant cost savings.

The low number of required moving parts in the system also entails low operating costs and high availability.

The system also does not cause any environmental impact in the form of emissions into the local environment, neither of water nor of residues from local treatment stages.

It is preferred that the mouth 126 of the drain line 124 be arranged substantially in the middle of the surface 130, at a height above the bottom of the collection container 121 which. is only a few centimeters, such as a maximum of 10 cm, higher than the maximum wastewater depth. It is also preferred that the mouth 126 be arranged so that the waste water is supplied substantially vertically downwards from the mouth 126. This minimizes the amount of splashing when supplying wastewater, which in turn increases the purity of the condensed water.

It is further preferred that the condensed water on its way between the storage container 123 and the second water toilet passes an activated carbon filter 116, i.e. a filter through which the water is forced to flow through porous activated carbon. This removes foul-smelling constituents of the condensed water, as well as certain other contaminants, which, for example, means that the flushing water does not smell bad in the toilet.

It is preferred that the storage container 123 and the collection container 121 be designed as a single, continuous space. In Figure 1, this is the case because the containers are connected to. each other. via a hole 131. The container 120 is arranged to direct water as condensed on the inside of the lid 122, by draining along the inner sides of the container 120, down to a gutter 127 which preferably runs around all the sides of the container 120, and which gutter 127 also slopes down towards the place along the gutter 127 where the hole 131 down to the storage container 123 is arranged. In this way all condensed water is led down to and along the gutter 127, up to the hole 131 and thereby down to the storage container 123.

Since the containers 121, 123 are only connected to each other via the hole 131, all condensed water will be fed to the storage container while the possibility of contamination from the collection container 121 to the storage container 123 is limited. It is further preferred that the container 120 be made of materials which are substantially impermeable to sunlight, and most preferably that the container 120 be largely or wholly buried in the ground 115. In this way, the space formed by the containers 121, 123 to be dark, whereby the growth of bacteria, algae and so on can be limited to sufficiently low levels without the use of chemicals.

According to a preferred embodiment, the above-mentioned return of condensed water from the storage container 123 back to the collection container 121 takes place by the contents of the storage container 123 widening over to the collection container 121, via the hole 131 in the illustrated exemplary embodiment Such widening means that the return can take place in a reliable and automatic manner, if necessary, without the need for any moving parts. It is noted that the maximum level of the waste water in the container 121 must be chosen to be lower than the height of the hole 131, since no liquid from the liquid body 128 can be allowed to flow directly from the body 128 down into the container 123.

It is further preferred that an amount of fresh water corresponding to the maximum amount of water in the storage container 123 in an initial step is supplied to the storage container 123. In other words, the storage container 123 is full at the beginning of the operation. Thus, when wastewater is supplied to the collection container 121 and condensed water flows down to the hole 131, none of this water will end up in the storage container 123, which is already filled to the brim. On the other hand, when flushing water is carried to the toilet 111, space is created for additional condensed water, which then continuously fills the container 123 up to a point when this atlet is filled to the width. In other words, during operation, the storage container 123 is continuously filled with condensed water up to the maximum amount of water in the storage container 123, after which further added condensed water causes the excess amount of water in the storage container 123 to be returned to the collection container 121.

The solution illustrated in the figures, in which gravity is used to carry water both from the container 121 to the non-movable de-container 123 and vice versa, is particularly advantageous, since the container 120 can then be made passive. It is understood, however, that instead of overflowing from the container 123, it would also be possible, for example, to arrange excess water from the container 123 to the container 121. for a separate pump or the like to carry Thus a quantity of water approximately corresponding to the initial amount of fresh water supplied at all times in the container 123, and the contents of the collection container 121 will always, in terms of chemical composition and degree of dryness, substantially correspond to the material added in addition to the flushing water in the toilet 111, the container 121. regardless of the total amount of wastewater in This gives a fraction with very predictable properties in the container 121, which in turn gives good digestion and hygienic results.

It is preferred that the first and second water toilets, the waste water collection container 121, the condensed water collection container 123, pipes 124, 125, all the pumps 112 described herein, the valves 340 and filters 116, the optional heating step 117, and so on, all constitute permanently installed parts of a fixed and permanently installed facility for the management of wastewater in a property that does not have a municipal sewer.

It is further preferred that only waste water from one or more water toilets is fed to the collection container 121 for waste water, and that no waste water originating from other types of waste producing units is fed to said collection container 121. This provides good conditions for both energy and nutrient recovery.

A control device 114 is further arranged to control the operation of the pump 112 and. any other necessary moving parts, such as valves, other pumps, and so on. In addition, the control device 114 is arranged to energize and control the heating device 117 in a suitable manner.

The purified water in the container 123 is thus used to flush in the toilet 11 and is thus returned to the container 121 for re-purification, whereby a cycle is achieved. By using both the waste water collection container 121 and the purified water collection container 123, it is possible for the water toilet III to be made self-sufficient in flushing water, even though the flow from and to the water toilet 111 is intermittent while the flow of condensed water to the water. pure l23 is rather limited per unit of time but on the other hand more or less continuous.

This is achieved through such a procedure and such a device that a property that is not connected to municipal sewers can be equipped with one or more water toilets.

Instead, it is sufficient that the much more limited amounts of sludge in the container 121 are emptied when needed. Such emptying can take place at regular intervals, alternatively when the contents reach a certain minimum volume and at the same time maintain a desired degree of dryness.

The volume of the container 121 can conveniently be monitored by means of a measuring equipment 113, for example in the form of a counter or a flow meter, which measures the number of flushes or the amount of flushed water in the toilet 111, and communicates this data to the control device 114. At the same time or alternatively the container 121 is measured by a measuring device 132 located therein, such as a level sensor, which also communicates measuring data to the control device 114.

Figures 2a-2b and 3a-3c, respectively, illustrate in principle two different embodiments of the container 120 illustrated in Figure 1, in the form of combination containers 200 and 300, respectively, comprising both respective collection containers 220, 320 for wastewater, arranged to receiving and housing a certain 330 arranged to receive and house a maximum amount of waste water, and storage container 230, for condensed water, certain maximum amount of condensed water.

It is understood that it is also the flue pipe 124, and a respective bottom hole 232, arranged to connect the pipe 125. is possible to arrange. the hole 232, the container 200, 332 in places other than in the bottom 300.

The combination containers 200, 300 are associated with a respective upright. operating orientation, in which the combination containers are oriented as illustrated in the figures, with a respective lid 210, 310 upwards.

The combination containers 200, 300 further comprise a respective condensing surface 213, 313, on which water which has evaporated from the collection container 220, 320 to a space 212, 312 arranged above a free liquid surface in the container 220, 320 for waste water, can condense.

When the respective combination container 200, 300 is oriented in said operating orientation, it is according to the invention arranged to direct the condensing surface on the condensing surface 213, 313. 330. the amount of condensed water, the respective combination container 200, 300 is arranged to return the excess amount to the collection container 220, 320.

It is preferred, as described above, that the respective storage container 230, 330 and the respective collection container 220, 320 be formed as a single, contiguous space.

As also described above, it is preferred that the respective combination container 200, 300 be arranged to return the excess amount of water in the storage container 230, 330 back to the collection container 220, 330. 320 by overflow from the storage container 230, In the combination container 200 this in that the container 220 is arranged as a free-standing container, 221 inside the container 230. arranged on legs. in a space 233 in the container 230 located below the container 220. The spreading then takes place by the water level in the container 230 rising all the way up to the upper edge of the container 220, after which spreading takes place. Such a construction is simple and thus cheap to manufacture.

In the combination container 300 the return takes place in that the container 330 is arranged below and in the extension of the container 320. An edge along the sides of the container 320 forms a gutter or surface 324, which partly slopes downwards outwards from a space 323 in the container 320 which is intended for collecting waste water, and slopes along the sides of the container 320 towards a place along the channel 324 where a hole 325 is arranged, which hole 325 leads downwards down to the container 330 and to a space 333 therein for condensed water. The chute 324 is thus arranged to catch and lead 313 to the hole 325. Spreading occurs when the water level in the container 330 reaches and condensation water from the condensing surface passes the level of the hole 325, possibly the edge of the chute 324. Such a construction, where the communication between the containers 320 and 330 is limited to one place, minimizes the contamination from the container 320 to the container 330 of the waste water.

In addition, a suitable valve 340, such as a valve which closes tightly as long as a certain minimum pressure in either direction is not present, may be provided in the hole 325 to further reduce the risk of contamination. Valve 340 is best seen in Figure 3c. It is preferred that the communication between the containers 320 and 330, whether limited to one or more holes, is limited to a total cross-sectional area of a maximum of 100 cm 7, more preferably a maximum of 10 cm 7, preferably a maximum of 1 cm 2, preferably a maximum of 0 cm 7. , 1 cmy.

It is preferred, as is clear in Figures 2a-3c, that the condensing surface 213, the holder 200, 313 i. 320, and also covering the collection container 220, 320.

Along the roof, water condensed on the surface 213, 313 can then flow down the sides of the roof and then be passed on to the storage container 230, 330 as described above. Since the roof is convex from the outside, it can be designed so that all or substantially all of the water that condenses on the condensing surface 213, 313 genius drainage is led down to the storage container 230, 330 rather than back to the collection container 220, 320. by dripping. A preferred convex design is a curved shape. The shape, as a semicircular, may be curved in a horizontal dimension, as in the examples illustrated in Figures 2a-3c, or in two horizontal dimensions, such as a hemispherical shape.

It is preferred that the respective lid 210, 310 be connected to either the storage container 230 or the collection container 320 by means of a connection 211 and 311, respectively, which is at least liquid-tight with respect to condensing water flowing down along the inner surfaces of the lid 210, 310 and passes the connection 211, 311.

As not illustrated in Figures 2a-3c, but in principle in Figure 1, the condensing surface may comprise a corrugated surface 133, for example in the form of a corrugated plastic insert arranged to divert condensation water, towards and through drainage, down along the container 120. inner walls for further transport to the container 123. Such a corrugated surface 133 increases the total condensing surface, which improves the turnover rate in the container 120.

As illustrated in both Figures 2a-2b and Figures 3a-3c, the respective combination container 200, 300 preferably comprises a double-bottomed structure, 234, 322, 333 between the outer 234, with an outer bottom 334 and an inner bottom 222, where in said The operating bases 334 and the 330 and 322 form the bottom of the collection container space 233, the inner 222, 322 the bottom constitute the storage container 230, where the inner bottom 222, the lugs 220, 320. Such a construction generally allows a simple construction with both containers 220 , 230; 320, 330 in 300, two containers which during operation are arranged separately. one and the same combination container 200, rather than as This is preferred because it is difficult to install two such separate containers completely or partially buried in the ground 115 without problems arising with relative sliding and consequent leaks.

It is further preferred that, as in Figures 2a-2b and 3a-3c, respectively, the double-bottomed structure is formed with a passage 225, 325 between the inner 222, 234, 322 and the outer 334 bottom, arranged along the double-bottomed structure. The outer edge of the tower, so that, when the combination container 200, 300 is oriented in said operating orientation, condensed water 313 and down into storage 325 can flow from the condensing surface 213, the ring container 230, 330 through the passage 225, It is preferred that the waste water collection container 121, 220, 320 have a maximum volume of waste water of at least 0.5 HÜ, more preferably at least 1 nÜ, more preferably at least 2 m 3, in order to be able to accommodate the waste water from the at least one water toilet III. 230, 330 The volume of the storage container 123 should be at least 0.2 nf, more preferably at least 0.5 but more preferably at least 2 mf. Preferred embodiments have been described above. However, it will be apparent to those skilled in the art that many changes may be made to the described embodiments without departing from the spirit of the invention.

For example, it is possible to design a facility according to the invention as a portable installation for use on boats, quays and natural harbors, on construction sites or other places where there is a need for a water toilet but no municipal sewer. In this case, the latrine is emptied from a water closet, such as a water closet installed on board. on a boat or a water toilet installed in a portable toilet, in the waste water collection container, and flushing water for use in said water toilet is filled from the condensed water storage container.

It is also possible to design a combination container according to the invention as illustrated in Figures 2a-2b, with a collecting container which is arranged inside the space defined by the storage container, but where the collecting container is rather held in place by means of a fastening 535 478 21 along its upper edge than »with. by means of 'ben sonl rests on the bottom of the storage container. Such a combination container can also advantageously be equipped with a gutter of the type illustrated in Figures 3a-3c.

Thus, the invention should not be limited to the embodiments described, but may be varied within the scope of the appended claims.

Claims (16)

A method for managing wastewater from a first water toilet (III), comprising the steps of: a) transferring the waste water from the first toilet to a locally arranged waste container (121; 220; 320) for wastewater ; b) allowing the waste water in the collection container to evaporate and condense again on a condensing surface; c) collecting the water thus condensed in a locally arranged. storage containers (l23; 230; 330) for condensed water; d) use the condensed water for flushing in. a second water toilet, which may be the same as the first water toilet; and e) removing from the collection container the sludge remaining in the collection container after further evaporation for further treatment, characterized in that, when the amount of water in the storage container exceeds a certain maximum amount, the excess amount of water is returned to the collection container. so that the dry content j. the collection container is kept within a certain range. 2. A method according to claim 1, characterized in that the entire residue in the collection container (l1l; 220; 320) for the waste water after evaporation of water is removed in step e), the sludge being removed to a central plant for further treatment. 3. A method according to claim 1 or 2, characterized in that the storage container (l23; 230; 330) and the collection container (l2l; 220; 320) are made to be designed as a single, continuous space. 15 25 30 538 478 23 A method according to any one of the preceding claims, characterized in that said excess amount of water in the storage container (l23; 230; 330) is returned to the collection container (l2l; 220; 320) by spreading from the storage container. A method according to any one of the preceding claims, characterized in that an amount of fresh water corresponding to the maximum amount of water in an initial step is supplied to the storage container (l23; 230; 330). A method according to claim 5, characterized in that (l23; 230; 330) operation is continuously filled with condensed water up to aV that the storage container is brought below the maximum amount of water, after which further added condensed water causes the excess amount of water in the storage container is returned to the collection container (112; 220; 320). 7. A method according to any one of the preceding claims, characterized in that external heat energy is brought to be supplied to the collection container (l2l; 220; 320). Method according to Claim 7, characterized in that the external heat energy can be supplied by means of an electric heating device (117). A method according to any one of the preceding claims, characterized in that (121; 220; 320) characterized in that the first water toilet is the second water toilet, the collection container (l23; 230; 330), all and the storage container (117) (340). ), any heating devices and necessary pipes (l24, l25) and valves are all made to form permanently installed parts of a fixed and. permanently installed facility for 15 25 30 35 538 478 24 wastewater management. in a property that. lacks municipal sewers. 10. lO. Method according to one of the preceding claims, characterized in that only waste water from one or more water toilets (lll) (l1l; 220; 320) is fed to the waste water collection container, and that no waste water originating from other types of waste-producing units is fed to said collection container. 11. ll. A method according to any one of the preceding claims, characterized in that the condensed water is brought to (116) (l23; 230; 330) and the second water toilet. pass an activated carbon filter between storage containers A system for managing wastewater from a first water toilet (III), comprising means for conveying the waste water from the first toilet to a locally arranged (l21; 220; 320) collection container arranged for wastewater, nad to receive and housing a certain maximum amount of wastewater, further where the system (l23; 230; 330) comprises a storage container for condensed water, arranged. to receive and. housing a certain maximum amount of condensed water, the system further comprising means for conveying said condensed water to a second water toilet, which may be the same as the first water toilet, for use in flushing therein, characterized in that. the collection container and the storage container are both contained in (120; 200; 300), a combination container which is associated with an upright operating orientation and which further comprises a condensing (213; 313) collection container, leaching surface on which water evaporated from can condense, by the combination container, when oriented. in the operating orientation, is arranged to direct the water condensed on the condensing surface to the storage container by means of gravity, and, when the amount of water in the storage container exceeds the certain maximum amount of condensed water, to return the excess amount to the collection container by widening from the storage container, and in that the combination container comprises a double-bottomed structure with an outer bottom (234; 334) and an inner bottom (222; 322), where in the operating orientation the space (233; 333) between the outer and the inner the bottom constitutes the storage container (l23; 230; 330) and the bottom (l2l; 220; 320). the interior forms the bottom of the collection container 13. Systenx according to claim 12, characterized in that the storage container (l2l; 220; 320) and the collection container are designed as a single, continuous space. A system according to any one of claims 12-13, (213; 313) the surface of an outwardly upwardly convex characteristic feature comprising the inner (222; 2010; 310), that the condensing surface which in the operating orientation is arranged vertically above ( l2l; 220; 320), which roof water which has condensed on the surface can run down along and cover the collection container and along the sides of the roof and then be passed on to the storage container (l23; 230; 330). System 1, according to any one of claims 12-14, characterized in that (2l3; 3l3) the condensing surface comprises a corrugated surface (133). System according to any one of claims 12-15, characterized in that the double-bottomed structure is formed with a passage (225; 325) between the inner (234; 334) (222; 322) and the outer bottom arranged along the edge of the double-bottomed structure, so that, when the combination container is oriented in the operating orientation, condensed water can flow from the condensing surface (ll3; 3l3) and down into the storage container (l23; 230; 330) through the passage.