Process for treating sewage using hydro fluoro ether polymers

A process for treating sewage containing biological solids including the steps of mixing the sewage with oxygen-containing hydro fluoro ether polymers, retaining the sewage with the hydro fluoro ether polymers for a desired period of time so as to produce oxygenated sewage and carbon dioxide-containing hydro fluoro ether polymers, and separating the carbon dioxide-containing hydro fluoro ether polymers from the oxygenated sewage. Water is separated from the oxygenated sewage so as to produce a sludge. Oxygen is mixed with the carbon dioxide-containing hydro fluoro ether polymers so as to oxygenate the hydro fluoro ether polymers and to remove carbon dioxide therefrom. The sewage is retained with the hydro fluoro etherpolymers at a temperature of between 32.degree. and 140.degree. F. The sewage is dewatered prior to mixing so that the dewatered sewage has a water content of less than 93 percent by weight. The steps of mixing and retaining can be carried in a closed vessel. The hydro, fluoro ether polymers can be an emulsion containing perfluoro-bis-chlorobutyl ether.

TECHNICAL FIELD
 The present invention relates to processes for the treatment of waste
 sludges. More particularly, the present invention relates to processes for
 the aeration of sewage prior to the treatment of the waste sludge.
 Additionally, the present invention relates to the use of hydro fluoro
 ether polymers for the treatment of sewage. Furthermore, the present
 invention relates to processes that render biological wastes
 pathogen-free, vector-free and sellable.
 BACKGROUND ART
 In the past, various techniques have been developed for the purpose of
 sterilizing or decontaminating biological sludges and wastes. The most
 common process is the process of mixing lime with the sludge. The reaction
 of lime with the water in the sludge serves to elevate the temperature of
 the sludge to a maximum of 100.degree. C.
 In the past, various U.S. patents have issued relating to processes for the
 decontamination and treatment of wastewater sludges. For example, U.S.
 Pat. No. 4,038,180, issued on Jul. 26, 1977 to N. K. Talbert, describes a
 process of dewatering sewage sludge in which the sludge from a municipal
 or industrial sewage treatment facility is mixed with a mineral acid or
 anhydride thereof to release the entrapped water in the sludge. The
 resulting mixture of the sludge solids and diluted acid or anhydride is
 then mixed with a basic material, such as ammonia, such that the heat
 generated by the reaction of the base and the acid evaporates the water to
 form either a completely dry mixture of sludge solids and a salt or a
 mixture having a predetermined moisture content which may be air dried.
 U.S. Pat. No. 4,500,428, issued on Feb. 19, 1985 to Lynch et al., describes
 a method for the treatment of a wastewater sludge using a pair of reaction
 vessels, sequentially, to treat the sludge. Both of the vessels are
 pressurized. The first vessel has an aerator for aerating the sludge. This
 vesl receives sulfuric acid and chlorine therein through a port. A
 dewatering device is provided upstream of the first vessel. The outlet of
 the first vessel is coupled to an inlet of the second vessel through
 another dewatering device. The second vessel creates a final-treatment
 chamber in which the sludge is exposed to ozone, air and lime.
 U.S. Pat. Nos. 4,781,842 and 4,902,431, issued to Nicholson, teach
 processes for the decontaminating of wastewater sludges to a level which
 meets or exceeds U.S. E.P.A. process standards. The process mixes sludge
 with an alkaline material sufficient to raise the pH of the end product to
 12 or higher for at least one day. This process will raise the temperature
 to 50.degree. C., but will not sterilize the sludge nor does it eliminate
 the pathogenic organisms.
 U.S. Pat. No. 4,306,978, issued to Wurtz, relates to a process of lime
 stabilization of wastewater treatment plant sludge. This patent discloses
 the dewatering of the sludge and intimately mixing calcium oxide to raise
 the temperature so as to produce a stabilized sludge particle.
 U.S. Pat. No. 5,482,528, issued on Jan. 9, 1996 to Angell et al., teaches a
 pathogenic waste treatment process for the processing of solid waste and
 for the converting of such solid waste into useful products. This is
 accomplished by combining the waste with an acid, such as concentrated
 sulfuric acid, and a base, such as fly ash. These exothermically react and
 thermally pasteurize the waste and add mineral value to the product.
 Pozzolanic materials, such as fly ash, agglomerate the product. The
 calcium oxide in the fly ash reacts with sulfuric acid to form calcium
 sulfate dihydrate.
 None of these prior art patented processes are capable of achieving
 temperatures, when mixed with the sludge, of greater than 100.degree. C.
 None of the prior art techniques allow for the shorter drying times as
 required by 40 C.F.R. Subchapter 0, Part 503.32.
 U.S. Pat. No. 5,635,069 issued on Jun. 3, 1997 to the present inventors.
 This patent described a process for treating a waste sludge of biological
 solids which included the steps of mixing the sludge with an
 oxide-containing chemical and sulfamic acid so as to elevate the
 temperature of the sludge, pressurizing the mixed sludge to a pressure of
 greater than 14.7 p.s.i.a., and discharging the pressurized mixed sludge.
 The oxide-containing chemical could be either calcium oxide, potassium
 oxide, or potassium hydroxide. The sludge has a water content of between 5
 and 85 percent. The oxide-containing chemical and the acid are reacted
 with the sludge so as to elevate the temperature of the sludge to between
 50.degree. C. and 450.degree. C. The pressurized mixed sludge is flashed
 across a restricting orifice or passed into a chamber having a lower
 pressure. The evaporated liquid component can be condensed and used as
 part of the process or external of the process.
 Typically, there are various problems associated with the treatment of
 sewage. It is fundamental that the sewage be aerated so that the aerobic
 microorganisms can be suitably supplied with oxygen such that they can
 consume the waste. In municipal applications, very large aerator
 assemblies are provided which continually bubble airthrough the sewage. It
 is desirable to introduce as much oxygen as possible into the liquid of
 the sewage. Through bubbling air techniques, a maximum of 9 parts per
 million of dissolved oxygen can be achieved in the liquid at about
 75.degree. F. Frequently, the oxygen content of the liquid will fall to
 such a level that the process becomes anaerobic. Under such circumstances,
 a horrible smell will be emitted by the waste processing facility. Since
 these municipal systems are open to the environment, when the process
 becomes anaerobic, there will be serious complaints by neighboring
 residents. Furthermore, these open top municipal treatment systems
 introduce enormous amounts of carbon dioxide and other hazardous air
 pollutants into the environment. The aerobic microorganisms consume the
 waste by converting it into carbon dioxide. Some of this carbon dioxide is
 emitted into the environment. This can exacerbate the "greenhouse effect".
 The metabolic rate of the aerobic microorganisms is only limited by the
 nutrients (the sewage) and by the oxygen uptake rate. As such, if greater
 amounts of oxygen could be introduced to the sewage, then the aerobic
 microorganisms would process the waste with greater rapidity.
 The cost for aerating the sewage is enormous. For a five million gallon per
 day facility, the energy cost for operating the aerators is approximately
 $80,000 dollars per month. Additionally, there is a relatively large
 capital cost associated with the installation of such aerating systems.
 Furthermore, because of the relatively small amount of oxygen that can be
 mixed into the water of the sewage, the processing facility must take up a
 considerable area. As a result, sewage is pumped into enormous open top
 tanks. Ultimately, the processed sewage will be discharged into the
 environment.
 Importantly, there have been significant developments in the creation of
 artificial blood. Artificial blood is used by the military for emergency
 use, in place of plasma, in field conditions. This artificial blood is a
 hydro fluoro ether polymer which contains long carbon chains. Oxygen
 molecules are connected to these carbon chains by a relatively weak bond.
 As result, when the artificial blood is passed through the human body, the
 blood is oxygenated by the substitution of carbon dioxide molecules for
 the oxygen molecules in the polymer. Since the carbon dioxide is attached
 to the carbon chains with a weaker bond than the oxygen molecules, the
 carbon dioxide molecules can be easily removed from the polymer and
 substituted with oxygen molecules. The carbon dioxide can be removed from
 the polymer by simply passing oxygen intimately with the polymer. As a
 result, carbon dioxide will be discharged from the polymer.
 This artificial blood, consisting of hydro fluoro ether polymers, is
 described in U.S. Pat. No. 5,567,765, issued on Oct. 22, 1996 to Moore et
 al., and in U.S. Pat. No. 5,785,950, issued on Jul. 28, 1998, to Kaufman
 et al. Each of these patents is owned by Minnesota Mining and
 Manufacturing Company of St. Paul, Minn. Each of these patents describes
 highly fluorinated chloro-substituted, non-cyclic organic compounds having
 7 to 12 carbon atoms. Importantly, it has been found that this hydro
 fluoro ether polymers can absorb an excess of 48 percent by weight of
 oxygen. As such, unlike the 9 parts per million achieved through the use
 of bubbling air through sewage, hydro fluoro etherpolymers can contain
 approximately 480,000 parts permillion of oxygen.
 It is an object of the present invention to provide a process for treating
 sewage which maximizes the amount of oxygen available to the aerobic
 microorganisms.
 It is another object of the present invention to provide a process for
 treating sewage which causes a processing of the sewage as completely and
 rapidly as possible.
 It is a further object of the present invention to provide a process for
 treating sewage which allows the treatment process to be carried out in a
 closed container.
 It is a further object of the present invention to provide a process for
 treating sewage which eliminates the need for aerators in the sewage tank.
 It is still a further object of the present invention to provide a process
 for treating sewage which allows for the containment of carbon dioxide and
 other hazardous air pollutants.
 It is still a further object of the present invention to provide a process
 for treating sewage which minimizes the capital and operating costs
 associated with the treatment of such sewage.
 It is still a further object of the present invention to provide a process
 which renders the sewage pathogen-free and vector-free.
 It is another object of the present invention to provide a process that
 converts the biological waste sludge into a sellable end product.
 It is still a further object of the present invention to provide a process
 for the treatment of sewage that is cost effective, easy to use and easy
 to install.
 These and other objects and advantages of the present invention will become
 apparent from a reading of the attached specification and appended claims.
 SUMMARY OF THE INVENTION
 The present invention is a process for treating sewage containing
 biological solids including the steps of: (1) mixing the sewage with
 oxygen-containing hydro fluoro ether polymers; (2) retaining the sewage
 with the hydro fluoro ether polymers for a desired period of time so as to
 produce oxygenated sewage and carbon dioxide-containing hydro fluoro ether
 polymers; and (3) separating the carbon dioxide-containing hydro fluoro
 ether polymers from the oxygenated sewage. The water is separated from the
 oxygenated sewage so as to produce a sludge. Oxygen is mixed with the
 carbon dioxide-containing hydro fluoro ether polymers so as to oxygenate
 the hydro fluoro ether polymers and to remove carbon dioxide therefrom.
 The carbon dioxide can be passed to a scrubber so as to separate residual
 oxygen therefrom. This residual oxygen can be introduced into the hydro
 fluoro ether polymers so as to oxygenate the hydro fluoro ether polymers.
 In the process of the present invention, the sewage is retained with the
 hydro fluoro ether polymers at a temperature of between 32.degree. and
 140.degree. F. The sewage can be dewatered prior to mixing such that the
 dewatered sludge has a water content of less than 93 percent by weight.
 The steps of mixing and retaining can be carried out simultaneously in a
 closed vessel.
 The process of the present invention further includes the steps of: (1)
 blending the sludge with an acid; (2) mixing an oxide-containing chemical
 with the blended sludge so as to cause a reaction which elevates a
 temperature of the sludge; (3) pressurizing the mixed sludge to a pressure
 of greater than 14.7 p.s.i.a for a period of time of no less than 15
 seconds; and (4) discharging the pressurized mixed sludge. The sludge will
 have a solids content of greater than 7 percent. The oxide-containing
 chemical can be calcium hydroxide, sodium hydroxide, potassium hydroxide,
 lithium hydroxide, calcium oxide, sodium oxide, potassium oxide or lithium
 oxide. The mixing of the sludge can be carried as a flow through a pipe. A
 pipe can be used so as to maintain the mixed sludge at a pressure of
 greater than 14.7 p.s.i.a. The pipe should have a length and diameter such
 that the flow of the mixed sludge will take longer than 15 seconds to pass
 through the pipe. The step of discharging can include the steps of
 flashing the pressurized mixed sludge across a restricting orifice and
 evaporating a liquid component of the sludge.
 In the preferred embodiment of the present invention, the hydro fluoro
 ether polymers can be an emulsion including perfluoro-bis-chlorobutyl
 ether. Alternatively, the hydro fluoro ether polymers can be an aqueous
 emulsion of a saturated C.sub.8 to C.sub.12 perfluorocarbon ether hydride
 selected from hydroperfluoroaliphatic ether, hydroperfluoroaliphatic ether
 substituted with a perfluoroalicyclic group, or a
 hydroperfluoroalicycloaliphatic ether and mixtures thereof, with water and
 a surfactant.

DETAILED DESCRIPTION OF THE INVENTION
 FIG. 1 is a flow diagram showing the process 10 in accordance with
 teachings of the preferred embodiment of the present invention. In the
 process shown in FIG. 1, the sewage 12 is initially introduced into a
 mixing chamber 14. The sewage 12, being raw sewage, will typically have a
 solids content of between 0.5 and 3 percent. Oxygenated hydro fluoro ether
 polymers 16 are also introduced into the mixing chamber 14 so that the
 oxygenated hydro fluoro ether polymers 16 can be intimately mixed with
 sewage 12 within the mixing chamber 14. The mixed sewage and hydro fluoro
 ether polymers are then passed along line 18 to a retention chamber 20.
 The retention chamber 20 serves to retain the mixture of hydro fluoro
 ether polymers and sewage in intimate contact for a desired period of time
 so that the aerobic microorganisms can effectively process the sewage.
 As stated previously, the hydro fluoro ether polymers can contain 480,000
 parts per million of oxygen. As such, a relatively small amount of the
 hydro fluoro ether polymers can be used so as to effectively provide
 oxygen to the microorganisms in the sewage. Relatively large amounts of
 oxygen turn the microorganisms into a virtual "incinerator" of the waste.
 Since the hydro fluoro ether polymers contain the oxygen for use by the
 aerobic microorganisms, the present invention does not require the use of
 aerators in the mixing chamber 14 or in the retention chamber 20. In fact,
 the mixing chamber 14 and the retention chamber 20 can be completely
 sealed to the external environment. The creation of carbon dioxide is
 effectively retained within such closed or sealed containers. As such,
 there is no discharge of carbon dioxide or other hazardous air pollutants
 to the external environment.
 In effect, the mixing chamber 14 and the retention chamber 20 can be the
 same item. For example, it is possible to introduce the sewage 12 and the
 hydro fluoro ether polymers 16 through a pipe, having a sufficient
 diameter and length along with static or dynamic mixers, so that the
 sewage 12 is maintained in intimate contact with the hydro fluoro ether
 polymers 16 for the desired period of time. The size of the retention
 chamber 20, if it is a pipe, can be set in accordance with the following
 formula:
 ##EQU1##
 where .rho. is the density of the sewage/hydro fluoro ether polymers
 mixture, F is the pounds per hour of processing, r is the radius of the
 retention chamber 20, and L is the length of the retention chamber 20.
 Under certain circumstances, the hydro fluoro ether polymers may be
 diluted with water or the sewage dewatered. As such, the length of the
 retention chamber should be properly set relative to the constraints of
 the system. For example, the retention chamber 20 can be of a shorter
 length or of a smaller diameter if purer hydro fluoro ether polymers or
 higher solids content sewage are processed.
 As can be seen in FIG. 1, the mixed hydro fluoro ether polymers and sewage
 are passed from the retention chamber 20 to a settling tank 22.
 Alternatively, the settling tank 22 could be in the form of a centrifugal
 separator or other form of separator. As can be seen in FIG. 1, the
 settling tank 22 allows the mixture to reside therein such that the hydro
 fluoro ether polymers 24 reside at the bottom of the tank 22. The sludge
 26 will reside as a layer above the hydro fluoro ether polymers 24. Water
 28 will reside above the sludge 26. In other words, the materials of
 greater density will settle toward the bottom of the setting tank 22.
 The hydro fluoro ether polymers 24 will have released their oxygen and be
 saturated with carbon dioxide after mixing with the sewage. The oxygen
 molecules on the polymer chain will be replaced with carbon dioxide. The
 aerobic microorganisms have absorbed the oxygen molecules from the polymer
 chains from the hydro fluoro ether polymers 24. As can be seen, the hydro
 fluoro ether polymers 24 will pass as carbon dioxide-containing hydro
 fluoro ether polymers along line 30 to an oxygenating chamber 32.
 When the carbon dioxide-containing hydro fluoro ether polymers reside in
 the oxygenating chamber 32, air or oxygen can be bubbled up through the
 carbon dioxide-containing hydro fluoro ether polymers 34 so as to release
 gases 36 therefrom. A supply of air or oxygen 38 is connected to the
 oxygenating chamber 32 so as to allow for the bubbling up of air or oxygen
 through the carbon dioxide-containing hydro fluoro ether polymers. In this
 manner, the carbon dioxide molecules are displaced from the polymer chains
 and replaced with oxygen molecules. The oxygenating chamber 32 is a closed
 container so as to avoid the release of carbon dioxide, and other gases,
 into the environment. The gases 36 are released along line 40 into a
 scrubber 42. The scrubber 42 can be used so as to remove the gaseous
 byproducts 44. Additionally, the scrubber 42 can be used so as to pass
 excess oxygen along line 46 back to the oxygenating chamber 32.
 In the process of the present invention, some of the hydro fluoro ether
 polymers will deteriorate in their oxygen-containing capacity over time.
 Other hydro fluoro ether polymers will be lost during the processing of
 the sewage. As such, a hydro fluoro ether polymers supply 48 can be
 connected along line 50 to the oxygenating chamber 32 so as to replenish
 any lost hydro fluoro ether polymers.
 The oxygenated hydro fluoro ether polymers 52 are then passed from the
 oxygenating chamber 32 back along line 54 to be introduced as an input to
 the mixing chamber 14. As a result, the process provides a closed loop for
 the hydro fluoro ether polymers used in the system. Since hydro fluoro
 ether polymers are relatively expensive, it is desirable to minimize the
 loss of hydro fluoro ether polymers during the processing.
 In FIG. 1, the settling tank 22 has sludge 26 residing above the hydro
 fluoro ether polymers 24. This sludge 26 can be passed along line 56 to a
 dewatering system 58. In the dewatering system 58, it is common to use a
 conveyor belt onto which the dewatered sludges are placed Various other
 dewatering techniques can also be employed so as to reduce the water
 content of the sludge to less than 93 percent. After dewatering, the
 dewatered sludge can be passed along line 60 to the BIOSET (TM) process
 62. The BIOSET (TM) process 62 is described in association with FIG. 3 and
 is presently the subject of U.S. Pat. No. 5,635,069. The product of the
 BIOSET (TM) process can be passed outwardly therefrom along line 64 as a
 pathogen-free and vector-free product.
 Water resides as the top layer 28 in the settling tank 22. The water from
 the processed sewage 12 can be passed outwardly of the settling tank 22
 along line 66 into the environment. Typically, the water will be
 discharged into a river or stream or into a tank for treatment. A
 disinfectant 68, such as chlorine, can be used so as to assure that the
 water 28 is sufficiently pure for discharge. Similarly, the water 70
 resulting from the dewatering system 58 can be passed outwardly along line
 72 into the environment 74. Similarly, the water 76 resulting from the
 BIOSET (TM) process 62 can be discharged along line 78 to the environment.
 FIG. 2 shows a variation on a process illustrated in FIG. 1. Within the
 concept of the preferred embodiment of the present invention, it may be
 desirable to dewater the sewage 80 prior to mixing with the hydro fluoro
 ether polymers. In the dewatering stage, the sewage 80 can be passed along
 a conveyor so as to separate much of the water from the sewage 80. The
 dewatering stage 82 should be sufficient such that the dewatered sewage
 passing therefrom will have a water content of less than 93 percent by
 weight. The dewatered sewage is passed along line 84 into the mixing
 chamber 86. In the mixing chamber 86, the dewatered sewage can be
 appropriately mixed with the hydro fluoro ether polymers 88. Also, as
 illustrated in FIG. 2, it can be seen that the hydro fluoro ether polymers
 88 can be maintained with the dewatered sewage and retained therein for a
 sufficient time so as to carry out the proper processing of the sewage.
 The mixing chamber 86 can be the same item as the mixing chamber 14 and
 the retention chamber 20 (as illustrated in FIG. 1). The mixed hydro
 fluoro ether polymers and dewatered sewage will pass outwardly of the
 mixing chamber 86 along line 89 to the settling tank 22 (as illustrated in
 FIG. 1).
 FIG. 3 is an illustration of the BIOSET (TM) process 62. In the BIOSET (TM)
 process 62, the dewatered sludge is delivered for processing so as to
 produce apathogen-free and vector-free end product. In the BIOSET (TM)
 process 62, the sludge 132, an acid 134, and an oxide-containing chemical
 136 are delivered together into a feed hopper 138. The dewatered sludge
 132 will have a solids content of greater than 7 percent or a water
 content of less than 93 percent. It is important for the sludge 132 to
 have a water content such that the remaining chemicals introduced to the
 process can properly react with the sludge.
 Within the present invention, the preferred acid 134 is sulfamic acid.
 Sulfamic acid is otherwise known as amidosulfonic acid (H.sub.3 NO.sub.3
 S). Sulfamic acid is obtained from chlorosulfonic acid and ammonia or by
 treating urea with H.sub.2 SO.sub.4. Typically, sulfamic acid is otherwise
 used in acid cleaning, in nitrite removal, and in chlorine stabilization
 for use in swimming pools, cooling towers, and paper mills.
 Importantly, within the concept of the present invention, the acid 134
 which is used is not limited to sulfamic acid. Various other acids could
 possibly be used provided a suitable amount of heat could be imparted to
 the sludge as it passes a later point in the process of the present
 invention. For example, carbon dioxide could be substituted for the
 sulfamic acid. The carbon dioxide would form carbonic acid when reacted
 with the waste sludge. Although experiments have shown that such carbonic
 acid would not optimally work in the process of the present invention, it
 would be possible to use such carbonic acid, or other acids, so as to
 accomplish the purposes of the present invention.
 After the sludge 132, the acid 134 and the oxide-containing chemical 136
 are added together into the feed hopper 138, the mixture is auger fed into
 the feed section 140 of a screw conveyor 142. The screw conveyor 142 will
 rotate so as to transport the mixture of the sludge 132, the acid 134 and
 the oxide-containing chemical 136 to a feed section. During the transport
 of the mixture of the sludge 132, the acid 134 and the oxide-containing
 chemical 136, these materials are mixed together by the screw conveyor.
 As used in the present invention, the oxide-containing chemical 136 can be
 either calcium hydroxide, sodium hydroxide, potaasium hydroxide, lithium
 hydroxide, calcium oxide, sodium oxide, potassium oxide and lithium oxide.
 In the preferred embodiment of the present invention, the oxide-containing
 chemical 136 could be calcium oxide. Other ingredients can be added to the
 feed section 140, if desired. These other ingredients could be passed
 along with the oxide-containing chemical 136 or otherwise delivered into
 the feed section 140. These materials are then transported to the
 compression zone 144 of the screw conveyor 142. This compression zone 144
 serves to increase the pressure of the mixed sludge to the desired value.
 Specifically, the compression zone 144 should increase the pressure of the
 mixed sludge to a pressure of greater than 14.7 p.s.i.a. Experimentation
 has found that the desired effects of the present invention are achieved
 by pressurizing the mixed sludge to a pressure of between 14.7 p.s.i.a.
 and 120 p.s.i.a. Importantly, the preferred pressure is greater than 20.7
 p.s.i.a. At such pressures, water is retained in the mixture and is not
 flashed from the system. When the water is flashed by pressures of less
 than 20.7 p.s.i.a., there is a loss of heat of approximately 1,000 BTU per
 pound of water. As such, to preserve the optimal heating effects in the
 process of the present invention, it would be desirable to maintain the
 pressure on the mixture to a level which would prevent the flashing of the
 water. Furthermore, the higher pressure keeps any ammonia (NH.sub.3) from
 flashing and retains the ammonia for intimate mixing with the pathogens of
 the waste sludge. The ammonia byproduct produced from the process of the
 present invention is an effective chemical for the killing of pathogens in
 the sludge.
 The adding of the oxide-containing chemical 136 and the increasing of
 pressure through the motive force of the screw conveyor 142 causes an
 exothermic reaction along the reaction section 146. The combination of
 calcium oxide and the water within the waste sludge produces calcium
 hydroxide and liberates 235 kcal/mole of heat. This raises the temperature
 from ambient to 100.degree. C. in 0.5 seconds. The sulfamic acid 134 then
 reacts with the calcium hydroxide to form calcium salts. This raises the
 temperature from 100.degree. C. to 140.degree. C. in less than 1 second.
 In the present invention, the oxide-containing chemical 136 can be produced
 from any source, such as kiln dust or lime dust. The oxide-containing
 chemical 136 will make up between 5 percent and 50 percent of the waste
 sludge 132 by weight. The acid 134 that is added, in any form, whereby the
 weight ratio of acid 134 to the oxide-containing chemical 136 is between
 0.33:1 and 1:1. In general, the temperature of the reaction chamber 146
 will be between 50.degree. C. and 450.degree. C.
 The material which exits the screw conveyor 142 enters pipe 146 having
 insulation 147 extending therearound. This pipe 146 can contain static
 mixing elements. The material is continuously mixed as it progresses
 through the predetermined length of the pipe. The material is continuously
 under pressure within the pipe 146 so as to prevent a premature flashing
 of the water within the mixed sludge. The mixed sludge will pass as a flow
 through the length of the pipe 146. The pipe 146 should be sized so as to
 have a length and diameter such that the flow of the mixed sludge will
 continue through the pipe 146 for a period of no less than 15 seconds. The
 intimate mixing of the ammonia with the pathogens of the mixed sludge at
 such an elevated temperature and under such an elevated pressure will
 effectively destroy any pathogens or vectors which would occur within the
 mixed sludge. The intimate contact of the sludge with the ammonia provides
 great disinfecting action to the waste sludge. The pressure within the
 pipe 146 will prevent the ammonia from flashing. Experiments with the
 present invention have shown that it will reduce pathogens from 2.2
 million colonies per gram to less than 10 colonies per gram.
 After reacting within the pipe 146, the mixed sludge is flashed across a
 restricting orifice 156. This restricting orifice 156 can be an opening, a
 die, or a valve. The orifice 156 is positioned generally adjacent to the
 end of the pipe 146. The orifice 156 will communicate with a flash chamber
 158. As such, the material is delivered under pressure to the orifice 156
 and then released into the flash chamber 158. A vapor, including water
 vapor, NH.sub.3, S0.sub.2, and S0.sub.3, will exit the flash chamber 158
 through the vent 160. This vapor can then pass to a container 162. The
 products of the process can then be sold as valuable byproducts external
 of the system.
 In order to properly remove the water from the sludge, it is important that
 the flash chamber 158 has an interior pressure of between 0 and 14.7
 p.s.i.a. As such, when the mixed sludge passes through the orifice 156,
 the sludge will be exposed to a lesser pressure. This causes the water and
 other volatile components of the sludge to be evaporated. As a result, the
 water content and the temperature of the sludge are appropriately reduced.
 The heat of vaporization of the flashed material can be passed directly
 back to the sludge by using heat exchangers, pumps or vapor compressors.
 After the sludge passes into the flash chamber 158, the resulting sludge
 will be a sterile decontaminated product which is pathogen-free and
 vector-free. This product will meet or exceed U.S. E.P.A. standards.
 The sterilized sludge then exits the flash chamber 158 through the
 discharge opening 164.
 The geometric configuration of the flash chamber 158 is dependent upon the
 layout configuration of the facility in which it is used. The flash
 chamber 158 should have a sufficient diameter and length so as to provide
 a residence time of the sludge within the chamber of greater than 15
 seconds. The insulation 147 is provided so as to eliminate heat loss and
 to produce an adiabatic reaction.
 Tests have been conducted with the configuration of the present invention.
 The experimental data associated with the process of the present invention
 is identified in Table I hereinbelow. During these experiments, oxalic
 acid was included in the experiments. However, it was later determined
 that the oxalic acid is a temperature depressor and can be a poison. As
 such, oxalic acid should not be included as part of the process of the
 present invention Other test results have shown that acids such as
 HN0.sub.3 acid, acetic acid, and vinegar acid do not achieve the necessary
 reaction so as to significantly increase the temperature of the waste
 sludge.
 TABLE I
 OXALIC SULFAMIC TIME TO
 OXALIC SULFAMIC WAT- REACH
 EXP CaO ACID ACID ER TEMP
 # gr. gr. .epsilon.r. cc. TEMP F. mins.
 1 189 75 58 24 300 8
 2 169 75 112 24 607 8
 3 337 153 224 24 619 8
 4 337 308 112 24 580 4
 5 189 75 168 24 400 1
 6 169 75 112 24 667 5
 7 50 40 87 24 250 1
 8 169 0 130 24 840 1
 9 189 130 0 24 370 1
 10 189 0 0 12 213 0.2
 11 0 75 0 12 0 1
 12 0 0 50 12 0 1
 13 189 130 0 24 500 3
 14 189 0 130 24 620 1
 15 85 0 85 24 700 1
 16 189 0 130 24 750 1
 17 189 0 130 72 750 1
 18 169 0 189 24 800 1
 The foregoing and description of the invention is illustrative and
 explanatory thereof. Various changes in the details of the illustrated
 construction or of the steps of the described method made within the scope
 of the appended claims without departing from the true spirit of the
 invention. The present invention should only be limited by the following
 claims and their legal equivalents.