METHOD AND DEVICE FOR RECLAIMING WASTE FROM A WATER-CLOSET

Abstract: The invention refers to a process for sanitarily reclaiming the waste from a water-closet, especially from a water-saving closet, and an arrangement for using the process. The process involves deposition of fecal sludge in a first, closed chamber (1), transferring of excess liquid into a second chamber (2) in communication with the first chamber (1), adding burnt lime to the first chamber for raising the pH level therein to about pH 12 when the two chambers are filled after about 12 months usage, thereby killing infectious bacteria and virus, and further urging gaseous ammonium from the urine into the second chamber. The arrangement comprises a container having a first, closed chamber (1) and a second, closed chamber (2), the chambers being in communication via an interconnection (3) having means for shutting off the communication, the interconnection being displaceable from a position wherein liquid and gas may flow between the chambers, to a position wherein liquid is prevented to flow from chamber (1) into chamber (2), whilst gas is allowed to flow freely through same interconnection.

Description: TITLE Method and device for reclaiming waste from a water-closet. TECHNICAL FIELD The present invention relates to a process and arrangements for a water- closet, and more precisely to a process for sanitarily reclaiming the wastes for successive use as manure, as defined in the preamble of claim 1 , and an arrangement as defined in the preamble of claim 5. BACKGROUND OF THE INVENTION Modern technology for purification of water is widely considered to eliminate intestinal and stomach disease. This assumption may be correct in aspects of bacterial infections like Salmonella, however, at present the technology may still be insufficient for eliminating viral infections in the stomach/intestinal organs. Polio is the most widely known stomach/ intestinal virus that is not eliminated through conventional water purification technology. For considerable time, this was believed not to be a problem when once a vaccine had been developed. Unfortunately, new and related virus types have spread widely, such as the Echo-virus and the Coxsackie-virus. A majority of those infected suffer only from a relatively non-complex intestinal disease, however some may develop meningitis, myocarditis or auto-immune diseases such as juvenile-onset diabetes (especially from the Coxsackie B-virus). These types of diseases have been increasing, and is expected to increase successively. This picture is also relevant in connection with polio, where substantially all individuals that were exposed to the virus were infected although very few suffered from the typical paralyses. Another unfavorable aspect is the low virus-doses that cause stomach/intestinal infections, such as about 100 times less for the Coxsackie- virus: 10- 100 virus particles compared to about 1 ,000- 10,000 bacterial par- tides. Furthermore, the virus survives up to about 6 months in a recipient, compared to a survival time of about 2-3 weeks for bacteria. It is therefore a need for avoiding these problems, related to conventional systems for purification of wastes, to the best possible extent. Further, it has long been realized that human urine and solid waste produces high value manure for the agricultural industry. In SE 52395 from 1918, e.g., there is disclosed a method for processing manure from human latrine and wherein calcium, wood ashes, fish gut waste and sulfuric acid is added to the latrine waste. This method however suffers from poor efficiency and problems in practice. First, although wood ashes is a substance that may be added in order to achieve a pH -level which allows for a purification treatment of the processed manure from an infectious aspect, the cadmium content in wood ashes is such that the manure hardly will be suitable for plant growth. The addition of fish gut waste mentioned in the aforesaid document seems merely to be another way of disposing with the matter, which is probably better composted in alternative ways. Additionally, this document advises that the nitrogen content of the urine is recovered by binding to sulfuric acid, however, the wood ash will neutralize the sulfuric acid and the ammonia will almost instantly vaporize. Generally speaking, previous methods for processing manure from human latrine waste are suffering from drawbacks that are mainly the result of inadequate knowledge about the processes involved, especially about the infectious substances in the waste. In the course of supplying manure and manure, it is desired to effect a distribution of nitrogenous substances to growing plants only at certain periods of time, in order to avoid a drainage to the ground from various forms of nitrogen content in the manure. When distributing waste from latrines for manure purposes, it is also desired to separate the nitrogenous fractions from other fertilizing substances that are not disposed for drainage to the same extent, as is the nitrogenous fractions. Previous separation systems are known, wherein fecal material is separated from urine in the water-closet, and which admits a reclaiming of nutrient salt from human in a manner that is sanitarily acceptable. However, this known procedure is not able to solve the problem of separating the nitrogenous fractions from the latrine waste. Accordingly, there is a need for methods to separate nitrogenous fractions from human latrine waste, in order to make it suitable for manure purposes. OBJECT OF THE INVENTION An object of the present invention is to provide a solution to the above said problems in order to prevent the distribution of stomach/ intestinal bacteria and virus that commonly occur in the waste water, and in order to effectively separate the nitrogenous fractions from the waste material so as to provide one fraction that is rich of nutrient salts such as calcium, phosphor, magnesium, etc., and which is suitable as a manure depot, and to provide another fraction that is rich of nitrogen, primarily as urea, ammonium and nitrate, and which is suitable as supplemental manure. An object of this invention is accordingly to fully eliminate pathogenic bacteria and virus, and to separate the nutrient salts into one fraction that is rich of calcium and phosphor to be used as a manure depot, and another nitrogenous fraction to be used as supplemental manure. SUMMARY OF INVENTION The above and other objects are met in a process for sanitarily reclaiming of human latrine waste as defined in appended claim 1 , and in an arrangement for reclaiming of latrine waste as defined in claim 7. DRAWINGS The invention will be more fully disclosed below, reference being made to the attached drawings wherein Fig. 1 is a schematic diagram, showing the reclaiming arrangement of the present invention in a step wherein a container is filled from a chamber 1 ; Fig. 1 b shows a detail of fig. 1 ; Fig. lc is a diagrammatic view, showing the reclaiming arrangement of the present invention in a step wherein the chamber 2 is about to be emptied; Fig. 2 shows a buffer line for 1.0 kg of fecal waste material; Fig. 3a is a diagrammatic view showing water drainage from the fecal sludge; Fig. 3b is a diagrammatic view showing evaporation of fecal sludge, and Fig. 4 is a diagram showing the inactivation time for the Coxsackie virus at 5°-8 C. DETAILED DESCRIPTION OF THE INVENTION First, there will be disclosed a preferred embodiment of an arrangement according to the invention. Fig. la is a schematic drawing showing an arrangement according to the present invention, comprising a container T having a first chamber 1 and a second chamber 2. The chamber volumes, which receive latrine waste via a pipe L and preferably from a water- saving closet, are preferably up to 0,5 m 3 / individual person. Chambers 1 and 2 are communicating through a connecting pipe 3, that preferably is movable from one position to another and having close off means. In a first embodiment, the first chamber 1 is provided a partition wall 4, separating the volume in one end of the chamber where the waste and flush water enters from the volume of the other end of the chamber 1 next to chamber 2 and the interconnecting pipe 3. In said other end of chamber 1 , the water-closet waste is received for sedimentation of fecal material. The chamber 2 is a storage volume for excessive liquid. By introducing, in one embodiment of the invention, the waste in chamber 1 on the left hand side of the partition wall 4 in figs, la and lc of the drawings, i.e. to that side of the partition wall 4 that is facing away from chamber 2, the fecal sludge forms a filter 6 that separates newly introduced material in order to minimize the volume of infectious sludge that may reach into chamber 2. Further, the chamber 1 comprises a stirring means such as a pump, adapted for stirring of the sludge sediments in chamber 1 in a later sequence. Connection pipe 3 is preferably arranged as shown in fig. lb. The pipe 3 is shown as a curved tubing, movable from a position wherein liquid is prevented to flow from chamber 1 to chamber 2, to another position wherein the pipe mouth is facing toward a side or the bottom of the chamber 2 in a sequence where the chamber 2 is filled with liquid. Additionally, the chamber 2 is shown to be closed through a cover 2a, covering an opening. In another embodiment, not shown in the drawings, the connection pipe is formed from a flexible material so that the pipe may be curved upwards by pulling, e.g. through a rope or other similar arrangement, the end of the pipe reaching into the chamber 2. Another important feature of the interconnecting pipe, as used in the present invention, is that gas is permitted to escape from the first chamber 1 into the second chamber 2 when fluid is not permitted to pass from chamber 1 to chamber 2, when the pipe is turned or otherwise moved to the position shown in fig. lb. A man of ordinary skills in this art realizes, that various arrangements may be used in order to secure the communication between the first and second chambers. It is essential though, that any such arrangement meets the operational features that are required according to the present invention. Additionally, fig. la illustrates how the fecal sludge is discharged via a conduit, a piping, a hose or similar means as shown with an arrow 7. The cover la of chamber 1 , shown in fig. lc, is then removed. Fig. lc shows the arrangement of the invention in a state wherein chamber 2 is filled and about to be emptied from excess liquid. Said excess liquid comprises a comparatively concentrated mixture of nitrogenous nutrients and flush water. In the drawing, the communication between the chambers is schematically shown to be shut off completely by suitable means such as a valve 8, mounted in the pipe 3 of the invention according to fig. lb. Excessive liquid from chamber 2 is discharged via a conduit, a pipe, a hose or similar means illustrated by an arrow 9. The chamber 2 is then opened, whereas chamber 1 is closed by the cover la and not intended to be emptied. Below, a preferred embodiment of a method for performing the invention will be described. Waste and flush water from a water-closet, preferably from a water-saving closet, is introduced in a first chamber 1. In said first chamber, the fecal material is settled such that excessive liquid is accumulated on the sediment to flow further into a chamber 2. As the two chambers 1 and 2 are filled, generally at a time interval of about 12 months, the pH level of the first chamber 1 is raised to about 12. This is preferably achieved by supplying calcium oxide CaO to the first chamber 1. Through such rise of the pH level, pathogenic bacteria and virus are destroyed and ammonium of the urine is simultaneously forced into chamber 2 via interconnection pipe 3, as illustrated by arrow 5, where the ammonium is again dissolved in chamber 2. To reach said pH level, about 1 mole CaO per each kg of fecal material is required (fig. 2), i.e. 40 moles or about 2 kg of CaO is required for about 40 kg of fecal material as produce by a human individual. In order to distribute the calcium oxide, a stirring means such as a pump may be used for mixing. A low cost pump of non-complex structure will satisfy, as 40 kg of fecal material will expand to about 100 1 of quite soft sludge. Reaching a pH level of 12 also in the center of particles of fecal material having a size in the order of one centimeter, requires a dwelling time of at least one week after stirring. Then, the sludge and solution of nutrient salts may be discharged form chamber 1 , as illustrated by the arrow 7, for transport to farms. Due to the dimensions considered for the embodiment described, about 100 1 of alkaline liquid from the first chamber may flow into the second chamber. Such over flow is advantageously prevented by raising the mouth of interconnection pipe 3 in chamber 2 as performed in the arrangement according to the invention by designing an interconnecting pipe that is displaceable into a position where gas exclusively, and not liquid may pass from chamber 1 to chamber 2, illustrated in fig. lb. It has been found in practice that a pH value of 12 is a pH level in which pathogenic bacteria and virus are instantly killed. Raising the pH value, merely to make the sludge alkaline may certainly contribute to remove infectious contaminants from the sludge, however, a longer deposit time will be required. The dosage advised above gives as the result, that ammonium is expelled and forced to flow into the other chamber. The liquid in the second chamber will then include a material with a resulting pH of about 9. In the following time period of about 6 months, the first chamber is once again filled up (fig. 1), whereas the second 2 is kept isolated from the first by shutting off the interconnection of pipe 3. The closing of the pipe may be performed by means of a valve 8 or other means providing a similar function. If the connection is left open, ammonium will pass back to chamber 1. A dwelling time of 6 months is enough to kill pathogenic virus and bacteria at a pH level of about 9, said pH being the indirect result of depositing burnt lime in the first chamber. As an example of this, the dwelling time needed for inactivation of Coxsackie-virus is shown in fig. 4. A dwelling time of 4-6 months at 5-8° C in the second chamber results in practically a total inactivation also of a highly resistant virus such as the Coxsackie B virus. The non-infectious condition after 6 months means that the nutrient salt solutions from the second chamber 2 may be discharged, as illustrated by the arrow 9, to be transported to farms by a tank vehicle. Since the liquid is rich with nitrogen, it should be distributed to growing plants in respect of a supplementary manure. It should be noted, that the nutrient salt solution of chamber 2 comprises all the urine nitrogen, which results in a concentration that is two-fold as compared to the average - an important object in the course of reducing as far as possible the weight for a tank that is used for the distribution, as mentioned above. By the facts, that chamber 1 does not contain any volatile ammonium and that the rise in pH also causes a precipitation of phosphorus, the sludge may be dehydrated through filtration (fig. 3a) by, e.g., depositing the sludge on the ground to be covered by a plastic cloth 10, the cloth being provided in order to avoid odors. The water is then filtrated into the ground layers, whilst the sludge remains on the ground surface. This process is harmless since the water is already sanitary. The dehydrated sludge may be burnt, and the ashes that are rich of calcium and phosphor may be transported to farms. Due to an ion-exchange property of the sludge, an immigration of OH-ions will provide "sites" for fixation of nutrient salts such as magnesium, manganese and potassium. The fixation may be improved by performing the dehydration in peat, where the OH-ions exchange the hydrogen ions for potassium, e.g. As is illustrated in fig. 3b, the contents of the first chamber 1 may also be evaporated behind a glass utilizing solar energy. In this case, also potassium may be recovered. Ammonium nitrate will dominate in the nutrient salts of the second chamber. Being a volatile nitrogen compound, the nutrient salt solution should be distributed to growing plants as a supplementary manure. The risk of damages through densification is then obvious, however, due to a two-fold nitrogen content in the subject process as compared to a conventional system, the tank for distributing the manure will have a reduced weight. If desired, chamber number two may have less dimensions in order to further concentrate the ammonium nitrate.

Claims: CLAIMS 1. A process for reclaiming waste from a water-closet by means of an arrangement provided to receive said waste, the arrangement comprising two containers communicating through a connection having means for closing the communication there between, the process comprising separation of the toilet waste in a first fraction and a second fraction, characterized by the following steps separation of waste in a first fraction including fecal material and a second fraction including excess liquid through sedimentation in a first, closed chamber (1); transferring the second fraction including the excess fluid to a second chamber (2), communicating with said first chamber; raising a pH level at least to pH 12 in the first chamber, when the first chamber is filled with fecal material, and closing the communication between the first and second chambers when ammonium, generated as a result of raising said pH level, is forced into the second chamber. 2. The process of claim 1 , characterized in that the second fraction includes excess liquid reaching a pH level of pH 9 as a result of the treatment of the fecal material in the first chamber, and storing the liquid in the second chamber for about 6 months. 3. The process of claim 1 or 2, characterized by providing the first chamber to have a partition wall arranged between an inlet and the connection between the first and second chambers, such that the material that is previously received serves as a filter for successively received material by urging the excess liquid to flow below said partition wall for equilibration of the liquid levels on each side of the partition wall. 4. The process of claim 1 , 2 or 3, characterized by the use of burnt lime for raising the pH level. 5. The process of any previous claim, characterized by discharging the sludge from the first chamber (1) to be dehydrated through filtration, and burning the dehydrated sludge before distribution as a manure agent. 6. The process of claim 1 , 2 or 3, characterized by discharging the sludge from the first chamber ( 1) to be evaporated, and burning the evaporated sludge before distribution as a manure agent. 7. An arrangement for reclaiming wastes from a water-closet, characterized by a container (T), the container comprising a first, closed chamber (1) and a second, closed chamber (2), the first chamber operative to receive a fecal material component of the waste for sedimentation, and the second chamber (2) operative to receive excess liquid formed by said sedimentation for storing, the two chambers communicating via an interconnection (3), said interconnection being adjustable between a first position wherein the connection is operative to connect the chambers in order to allow excess liquid to flow into the second chamber, and a second position wherein the connection is operative to prevent liquid from flowing into the second chamber (2) from the first chamber (1), but allowing gases to move between the chambers ( 1 ,2), said interconnection having means (8) for closing the communication between the chambers (1 ,2) and the chambers being provided with means for individually emptying the chambers. 8. The arrangement of claim 7, characterized by the first chamber having a stirring means for stirring the fecal sludge. 9. The arrangement of claim 7 or 8, characterized by a partition wall (4) dividing the first chamber (1) in two portions, one of which is disposed near to the second chamber and the interconnection (3) between the chambers, and the other one, on the opposite side of the partition wall, near to a tubing (L) through which the waste is introduced into the container (T), the fecal material that is deposited behind the wall acting as a filter (6) for successively received material.

Inventors: WOLGAST MATS, WOLGAST, MATS
Applicants: SVENSSON LARS ERIK, WOLGAST MATS, SVENSSON, LARS-ERIK, WOLGAST, MATS
Application year: 2000
Main classification: C05F3
IPC codes: C05F3