System and process for water treatment

ES 2 392 598 T3

DESCRIPTION

Process for treating water using a high-speed shear device

BACKGROUND OF THE INVENTION

Technical field

[0001] The present invention relates generally to water treatment. More particularly, the present invention relates to the high shear rate process for water treatment. The published method can be used to treat untreated or wastewater containing contaminants by which contaminants can be disinfected, stabilized and / or separated from the water.

Background of the Invention

[0002] The processes for recycling wastewater from industrial activities present challenging environmental problems and the government regulates these processes. The impact on the environment of wastewater used in industrial activities has led to the creation of regulations at both the local and federal levels. These regulations require the cleaning of wastewater before its discharge to the environment and / or its introduction into public sewage systems.

[0003] Various problems arise when cleaning industrial and residential wastewater. For example, wastewater often comprises significant amounts of suspended solids, undesirable dissolved minerals, and noxious gases. Wastewater can also comprise significant amounts of organic matter, including hydrocarbons (eg oils) and bacteria.

[0004] Furthermore, raw water from surface sources (eg springs) or groundwater sources frequently requires treatment to remove contaminants prior to use, eg prior to use as drinking water.

[0005] There are numerous strategies for water treatment. For example, chemical oxidation processes are routinely used to remove organic contaminants from wastewater. Physical wastewater treatment systems, including solid particle flocculation / flotation, are also common. However, there is still a need for improved industrial wastewater treatment processes that allow increased performance, increased contaminant removal, and / or the use of reduced amounts of treatment assistant (e.g. example gases such as chloride and air or liquids such as flocculants).

ES 2 392 598 T3

ABSTRACT

[0006] A high shear rate process for water treatment is published. The high shear rate process can reduce mass transfer limitations relative to conventional water treatment processes, thus increasing the speed of water treatment and potentially allowing a reduction in contact time, greater removal / neutralization of unwanted contaminants, and / or a reduction in treatment assistant. The process employs an external high-shear mechanical device to provide improved contact between the reactants. In some embodiments, this enhanced contact causes accelerated chemical reactions between the multiphase reagents. In one embodiment, the process comprises the use of an external pressurized high shear rate device for water treatment without the need for large volume vessels in which the water has high residence times.

[0007] A method for removing contaminants from feed water is published herein, the method comprising clamping a fluid mixture comprising a treatment gas and the feed water at a shear rate greater than 20,000 s-1 in a device of high shear rate to produce a dispersion of the treatment gas in a continuous phase of the feed water, in which the treatment gas is chloride. The method also comprising introducing the dispersion into a container from which an aqueous product is extracted; and separating particles from the aqueous product. The contaminants can comprise dissolved organic matter, the treatment gas can comprise air or oxygen, the container can be an aeration tank comprising microorganisms that consume organic matter, and the separated particles of the aqueous product can comprise microorganisms. At least a part of the particles can be recycled in the aeration tank. The dispersion can be stable for at least 15 minutes at atmospheric pressure.

[0008] Certain embodiments of the method described above, potentially provide more optimal time, temperature and pressure conditions than those possible with other methods, and potentially increase the speed of the water treatment process. Certain embodiments of the above-described methods potentially provide a total cost reduction by operating with reduced residence times, providing an increase in product per unit of treatment assistant consumed, and / or reduced capital and / or operating costs. These and other modes of implementation and potential advantages will be appreciated in the

ES 2 392 598 T3 following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, in which:

[0010] Figure 1 is a process flow diagram of the water treatment system according to an embodiment of the present publication.

[0011] Figure 2 is a longitudinal cross-sectional view of a multi-stage high shear rate device, as used in one embodiment of the system.

ANNOTATION AND NOMENCLATURE

[0011] As used herein, the term "dispersion" refers to a liquefied mixture containing at least two distinguishable substances (or phases) that will not easily mix or dissolve together. As used herein, a dispersion comprises a continuous phase (or matrix), which itself supports droplets, bubbles, and / or discontinuous particles of the other phase or substance. The term dispersion can therefore refer to foams comprising gas bubbles suspended in a continuous liquid phase, emulsions in which the drops of a first liquid are dispersed throughout a continuous phase comprising a second liquid with which the first liquid is insoluble , and the continuous liquid phases through which the solid particles are distributed. As used herein, the term dispersion encompasses continuous liquid phases through which gas bubbles are distributed, continuous liquid phases through which solid particles (for example a solid catalyst or contaminant) are distributed, liquid phases through which drops of a second liquid that is substantially insoluble in the continuous phase are distributed, and liquid phases through which any combination of solid particles, insoluble liquid droplets, and gas bubbles are distributed. Therefore, a dispersion can exist as a homogeneous mixture in some cases (for example a liquid / liquid phase), as a heterogeneous mixture (for example gas / liquid, solid / liquid, or gas / solid / liquid), depending on the nature of the subjects selected to combine. The term emulsion will be used here more specifically to refer to liquid / liquid or liquid / liquid / solid dispersions.

[0013] The term "treatment aid" will be used to refer to any component added to a contaminated water stream. For example, in

In an embodiment, a treatment assistant may comprise a treatment gas such as air, oxygen, or chloride gas. In other embodiments, the treatment assistant may comprise a liquid such as a liquid flocculating agent.

DETAILED DESCRIPTION

[0014] Overview The speed of chemical reactions involving liquids, gases and solids depends on the contact time, temperature and pressure. In cases where it is desired to react two or more raw materials of different phases (for example solid and liquid; liquid and gas; solid, liquid and gas), one of the limiting factors controlling the rate of the reaction comprises the time contact point of the reagents. In the case of heterogeneously catalyzed reactions there is an additional rate limiting factor to remove reactive products from the catalyst surface to allow the catalyst to catalyze other reactants. The contact time for the reactants and / or the catalyst is frequently controlled by mixing them, which provides contact with one or more reagents involved in a chemical reaction. In the case of homogeneous reactions, eg liquid / liquid reactions, improved mixing can increase the rate or extent of the interaction and also homogenize the temperature within the reaction zone (s).

[0015] A system and process for treating water comprises an external high shear rate mechanical device that provides rapid contacting and mixing of chemical ingredients in a controlled environment in the reactor / mixer device. The published high-shear rate system and method can be incorporated into conventional water treatment processes, thus improving the removal or neutralization of the contaminant (eg hydrocarbon, bacteria, noxious gas etc.) and / or the aeration rate. The high-speed shear device can be used in various water treatment processes, such as biological treatment processes that remove dissolved organic matter from water, physical separation processes, and chemical treatment processes. The use of the high shear rate can reduce the mass transfer limitations on the desired reactions / interactions and thus reduce the time required for water treatment, thereby increasing the achievable yield. The ejected product may increase as a result of the high shear rate system and process. The use of high shear rate contacting the treatment assistant with water to be treated may allow the use of smaller amounts of gas (e.g. air, chloride) and / or assistants.

ES 2 392 598 T3 liquid treatment (for example flocculating liquid agents) than in conventional water treatment processes.

The high shear rate system can be used to form a dispersion of a treatment gas in a liquid, for example, a dispersion of oxygen, air, or chloride in the water to be treated. Such dispersion can increase the amount of dissolved gas due to the reduced diameter of the bubbles in the dispersion, which typically have an average bubble diameter of less than about 5pm. Although not discussed in detail here, the high shear rate system can also be used to intimately mix two streams of liquid, for example, a stream of water to be treated and a liquid flocculating agent. In these embodiments, the high shear rate device can increase the flocculation of contaminants by the immediate effect of intimate mixing within the interaction zone (s).

[0017] Other uses of the published system and method will be perceptible upon reading the publication and upon observing the accompanying drawings. While the following description will be provided with respect to wastewater treatment processes comprising chlorination and aeration, the embodiments described herein serve as an example only, and not as a limitation. For example, the high shear rate system and process can be used for treating wastewater or raw water and can be used to increase chlorination and aeration particularly, or any combination of liquid and / or gas injection known to those. skilled in the art for use in treating streams.

[0018] Water treatment system. A high shear rate water treatment system will now be described in relation to Figure 1, which is a process flow diagram of an embodiment of a high shear rate water treatment system 1, for the water treatment comprising at least one contaminant that must be at least partially removed, stabilized and / or neutralized. Such a system can be used for aeration in a biological or biochemical wastewater treatment system according to the activated sludge or aeration system in an aerobic / aeration pond / lagoon. The high-speed shear process is used for the bactericidal treatment of water with chloride gas.

[0019] It is widely known that chloride can be used effectively to kill bacteria contained in water. Chloride is commonly used for the treatment of drinking water, and also for the treatment of water used in

ES 2 392 598 T3 swimming pool systems, and has been widely used to treat wastewater during wastewater treatment processes. Although adding chloride to water has proven to be an effective method of killing bacteria in water, it also has some drawbacks. First, chloride, which is a relatively volatile gas in its natural state, dissipates easily from water when exposed to the atmosphere, particularly when the water is above about 21 ° C (70 ° F). . Therefore, it is generally necessary to make frequent additions of chloride to the water under these conditions in order to keep the levels of bacteria in the water within safe ranges. This can be economically undesirable. As will be discussed below, the high shear rate system and process can allow a reduction in the amount of chloride required for water treatment and / or increase the speed of water treatment by minimizing resistance to mass transfer. through high shear rate mixing and creating a disinfectant gas dispersion in a continuous aqueous phase.

The basic components of a representative high shear rate system include an external high shear rate (HSD) mixing device, a container, and a pump. Each of these components is described in more detail below. As shown in Figure 1, the high shear rate device 40 is located external to the vessel / reactor 10. Line 21 is connected to the pump 5 to introduce water to be treated. Line 13 connects pump 5 to HSD 40, and line 18 connects HSD 40 to container 10. Line 22 may be connected to line 13 to introduce a treatment gas (eg, air, oxygen, or chloride) or a treatment assistant liquid. Alternatively, line 22 may be connected to an input of HSD 40. Line 17 may be connected to a vessel 10 for removal of unreacted treatment gas, hydrogen sulfide, or other gas removed from water by treatment. Additional process steps or components can be incorporated between vessel 10 and HSD 40 or ahead of pump 5 or HSD 40, if desired, as will be appreciated upon reading the description of the high speed water treatment process of shear described below.

The high shear rate system 1 may further comprise a preliminary treatment apparatus, such as unit 60 that can be used to remove large solids and fats from the water to be treated in line 25. Pretreatment unit 50 may be connected to pump 5 through line 21. High shear rate system 1 may also comprise a separator

ES 2 392 598 T3 subsequent to HSD 40 to separate heavy solids and reduced solids. Separator 30 may be connected to container 10 via line 16. Line 33 or line 36 of separator 30 may be connected to line 21 or line 13 to provide multi-pass operation, if desired. . The inlet lines can be incorporated into the high shear rate system 1 to introduce material into the system. For example, line 14 may be connected to a container 10 for introducing matter, such as a pH adjustment assistant, into container 10; and line 35 can be connected to line 16 or any other in a high shear rate system 1 to introduce matter, such as a flocculant, into high shear rate system 1. It should be noted that Figure 1 is a simplified process diagram and that potential pieces of process equipment, such as separators, valves, and compressors, have been omitted for clarity.

[0022] Pretreatment unit (s). The high shear rate system 1 may comprise pretreatment unit (s) 60 for the physical separation of the components of the water to be treated. The pretreatment unit 60 may be configured to separate large solid objects and / or grease from the water stream in line 25. Without limitation, examples of a suitable pretreatment apparatus are rod screens, sand tanks, and sedimentation tanks. .

[0023] High shear speed mixing device. The external high shear rate (HSD) mixing device 40, sometimes also referred to as a high shear rate device or high shear rate mixing device, is configured to receive an input stream, through line 13 , comprising the water to be treated and the treatment assistant. Alternatively, the HSD 40 may be configured to receive water and the treatment assistant through separate inlet lines (not shown). Although a high shear rate system 40 is shown in Figure 1, it should be understood that some embodiments of the system may have one or more than two high shear rate mixing devices configured in series or parallel flow. The HSD 40 is a mechanical device that uses one or more generators comprising a rotor / stator combination, each of which has a gap between the stator and the rotor. The space between the rotor and the stator in each generator series can be fixed or adjustable. The HSD 40 is configured in such a way that it is capable of producing sub-microns and micron-sized bubbles or droplets from the treatment assistant in an aqueous mixture flowing through the high-speed device.

ES 2 392 598 T3 shear. The high shear rate device comprises a structure or housing so that the pressure and temperature of the aqueous mixture can be controlled.

[0024] High shear rate mixing devices are generally divided into three general classes, based on their ability to mix fluids. Mixing is the process of reducing the size of inhomogeneous particles or species within the fluid. One way to measure the degree of stringency of mixing is the volume of energy density per unit that the mixing device generates to alter the fluid particles. Classes are distinguished based on the energy densities obtained. Three classes of industrial mixers with sufficient energy density to consistently produce mixtures or emulsions with particle sizes in the submicron to 5x10.5 m (50 micron) range including homogenizing valve systems, colloid mills, and high speed mixers . In the first class of high shear rate devices, called homogenizing valve systems, the fluid to be processed is pumped at very high pressure through a narrow port valve into a lower pressure environment. The pressure is graduated across the valve and the resulting turbulence and cavitation act to break up any particles in the fluid. These valve systems are commonly used in milk homogenization and can alter submicron particle sizes to a 1x10 range.^-6m (1 micron) approximately.

At the opposite end of the energy density spectrum is the third class of devices called low energy devices. These systems commonly have fluid blades or rotors that rotate at high speed in a reservoir of the fluid to be processed, which in many common applications is a food product. These low energy systems are commonly used when the mean particle size is greater than 2x10 '⁵m (20 microns) is acceptable in the processed fluid.

[0026] Among low-energy devices and homogenizing valve systems, in terms of the mixing energy density transmitted to the fluid, are colloidal mills and other high-speed rotor-stator devices, which are classified as intermediate energy devices. A typical colloid mill setup includes a disc or conical rotor separated from a complementary, liquid-cooled stator by carefully controlled rotor-stator spacing, typically between 0.02 mm and 10 mm (0.001-0.40 inches). Rotors are usually driven by an electric motor through a

ES 2 392 598 T3 direct or strap actuation mechanism. As the rotor rotates at high speed, it pumps fluid between the rotor and stator, and shear forces generated in the gap process the fluid. Most colloid mills with a proper setting achieve an average particle size of 1x10^-7m to 2.5x10^-5m (ü.1-25 microns) in the processed fluid. These capabilities provide colloidal mills suitable for a variety of applications including the processing of colloid-based and oil / water-based emulsion as required for the formation of cosmetics, mayonnaise, or of silicone / silver amalgam, for mixing tar of the roofs.

[0027] The peripheral speed is the circumferential distance traveled by the tip of the rotor per unit of time. Peripheral speed is therefore a function of rotor diameter and rotational frequency. The peripheral speed (in meters per minute, for example) can be calculated by multiplying the circumferential distance transcribed by the tip of the rotor, 2nR, where R is the radius of the rotor (meters, for example) by the frequency of revolution (for example revolutions times minute, rpm). A colloid mill, for example, can have a peripheral speed exceeding 22.9 m / s (4500 ft / min) and can exceed 40 m / s (7900 ft / min). For the purpose of this publication, the term 'high shear rate' refers to mechanical rotor stator devices (e.g. colloidal mills or rotor-stator dispersers) that achieve peripheral speeds exceeding 5.1 m / s (1000 ft / min) and require a mechanically activated external power device to transport energy to the reactant stream. For example, on the HSD 40, a peripheral speed greater than 22.9 m / s (4500 ft / min) is achievable, and can exceed 40 m / s (7900 ft / min). In some embodiments, the HSD 40 is capable of processing at least 300 l / h at a peripheral speed of at least 22.9 m / s (4500 ft / min). Power consumption can be about 1.5 kW. HSD 40 combines high peripheral speed with very small shear gap to produce significant shear in the material to be processed. The shear volume will depend on the viscosity of the fluid. Therefore, a local region of high pressure and temperature is created at the tip of the rotor during operation of the high shear rate device. In some cases the local elevated pressure is approximately 1034.2 MPa (150,000 psi). In some cases the local elevated temperature is around 500 °. In some cases, these elevated pressures and temperatures can persist for nanoseconds or picoseconds.

[0028] An approximation of energy input into the fluid (kW / L / min) can

ES 2 392 598 T3 be estimated by measuring motor power (kW) and fluid output (L / min). As mentioned above, peripheral velocity is the velocity (ft / min or m / s) associated with the end of one or more rotating elements that create the mechanical force applied to the fluid. In embodiments, the energy expenditure of the HSD 40 is greater than 100 W / m³. In embodiments, the energy expenditure of the HSD 40 is in the range of 3000 W / m³ and 7500 W / m³ about.

The shear rate is the peripheral speed divided by the shear gap width (minimum clearance between rotor and stator). The shear rate generated in the HSD 40 is greater than 20,000 s-1. In some embodiments the shear rate is at least 40,000 s-1. In some embodiments the shear rate is at least 100,000 s-1. In some embodiments the shear rate is at least 500,000 s-

1. In some embodiments the shear rate is at least 1,000,000 s-1. In some embodiments the shear rate is at least 1,600,000 s-1. In embodiments, the shear rate generated by the HSD 40 is in the range between 20,000 s-1 and 100,000s-1. For example, in one application the peripheral rotor speed is about 40 m / s (7,900 ft / min) and the shear gap width is 0.025 mm (0.001 in.) Producing a shear rate of 1,600,000 s- 1. In another application the peripheral rotor speed is about 22.9m / s (4500ft / min) and the shear gap width is 0.0254mm (0.001in) producing a shear rate of 901.600s-1.

[0030] The HSD 40 is capable of rapidly dispersing or transporting the treatment assistant in a main liquid phase (continuous phase) comprising water, with which it would normally be insoluble, under the conditions in which at least a part of the treatment assistant reacts / interacts with the contaminant in the water. In some embodiments, the HSD 40 comprises a colloid mill. Suitable colloidal mills are manufactured by IKA® Works, Inc. Wilmington, NC and APV North America, Inc. Wilmington, MA, for example. In some cases, the HSD 40 comprises the Dispax Reactor® reactor from IKA® Works, Inc.

The high shear speed device comprises at least one rotating element that creates a mechanical force applied to the aqueous mixture. The high-speed shear device comprises at least one stator and at least one rotor separated by a space. For example, the rotors may be conical or disc-shaped and may be separate from a complementary-shaped stator. In embodiments, both the rotor and the stator comprise a plurality of

ES 2 392 598 T3 circumferentially spaced teeth. In some embodiments, the stator or stators are adjustable to obtain the desired shear gap between the rotor and the stator of each generator (rotor / stator series). The grooves between the rotor and / or stator teeth can alternate direction in alternate phases for increased turbulence. Each generator can be activated with any suitable activation system configured to provide the necessary rotation.

[0032] In some embodiments, the minimum gap (shear gap width) between the stator and the rotor is in the range of about 0.0254mm (0.001 inch) to 3.175mm (0.125 inch). In certain embodiments, the minimum gap (shear gap width) between the stator and the rotor is approximately 1.5 mm (0.060 inches). In certain configurations, the minimum clearance (shear gap) between rotor and stator is at least 1.7 mm (0.07 inches). The shear rate produced by the high shear rate device can vary with longitudinal position along the flow loop. In some embodiments, the rotor is set to rotate at a speed commensurate with the rotor diameter and the desired peripheral speed. In some embodiments, the high-speed shear device has a fixed gap (shear gap width) between the stator and the rotor. Alternatively, the high shear rate device has an adjustable gap (shear gap width).

[0033] In some embodiments, the HSD 40 comprises a single phase dispersion chamber (eg, a single rotor / stator combination, a single generator). In some embodiments, the high shear rate device 40 is an in-line multiple phase disperser and comprises a plurality of generators. In certain embodiments, the HSD 40 comprises at least two generators. In other embodiments, the high shear rate device 40 comprises at least 3 high shear rate generators. In some embodiments, the high shear rate device 40 is a multi-phase mixer in which the shear rate (which, as mentioned above, varies proportionally with peripheral speed and inversely with width rotor / stator clearance) varies with longitudinal position along the flow path as described in detail below.

[0034] In some embodiments, each phase of the high shear rate device has interchangeable mixing tools, offering flexibility. For example, the DR 2000/4 Dispax 20 Reactor® reactor from IKA® Works, Inc.

ES 2 392 598 T3

Wilmington, NC and APV North America, Inc. Wilmington, MA, comprises a three-phase dispersion module. This module can comprise up to three rotor / stator combinations (generators), choosing between fine, medium, coarse, and super fine for each phase. This allows the creation of dispersions with a narrow distribution of the desired bubble (eg treatment gas bubbles). In some embodiments, each of the phases is activated by a super fine generator. In some embodiments, at least one of the generator sets has a minimum rotor / stator gap (shear gap width) greater than about 5mm (0.2 inches). In alternate embodiments, at least one of the generator sets has a minimum rotor / stator clearance greater than about 1.7 mm (0.07 inches).

Referring now to Figure 2, a longitudinal cross section of a suitable high shear rate device 200 is presented. The high shear rate device 200 of Figure 2 is a dispersion device comprising three phases or rotor-stator combinations. The high speed shear device 200 is a dispersion device comprising three phases or rotor-stator combinations, 220, 230 and 240. Rotorestor combinations are known as generators 220, 230, 240 or phases without limitation. Three rotor / stator arrays or generators 220, 230, and 240 are aligned in series along drive axis 250.

The first generator 220 comprises a rotor 222 and a stator 227. The second generator 230 comprises a rotor 223 and a stator 228. The third generator 240 comprises a rotor 224 and a stator 229. For each generator the rotor is activated accordingly. rotatably via input 250 and rotates about shaft 260 as indicated by arrow 265. The direction of rotation may be opposite to that shown by arrow 265 (eg clockwise or counterclockwise on axis of rotation 260). Stators 227, 228, and 229 may be fixedly coupled to wall 255 of high shear rate device 200.

[0037] As mentioned here above, each generator has a shear gap width which is the minimum distance between the rotor and stator. In the embodiment of Figure 2, the first generator 220 comprises a first shear gap 225; the second generator 230 comprises a second shear space 235; and the third generator 240 comprises a third shear space 245. In embodiments, the shear gaps 225, 235, 245 have a width in the range of 0.025mm to 10mm. Alternatively, the

The process comprises the use of a high shear rate device 200 in which the spaces 225, 235, 245 have a width in the range of about 0.5mm to 2.5mm. In some cases the width of the shear gap is kept at approximately 1.5 mm. Alternatively, the shear gap widths 225, 235, 245 are different for generators 220, 230, 240. In some cases, the width of the shear gap 225 of the first generator 220 is greater than the width of the shear gap 235 of the second generator 230, which is in turn greater than the width of the shear gap 245 of the third generator 240. As stated As mentioned above, the generators of each phase can be interchangeable, offering flexibility. The high shear rate device 200 can be configured so that the shear rate gradually increases longitudinally along the direction of flow 260.

[0038] Generators 220, 230, and 240 may comprise coarse, medium, fine, and super fine characterization. Rotors 222, 223, and 224 and stators 227, 228, and 229 may have a toothed design. Each generator may comprise two or more sets of rotor-stator teeth. In embodiments, rotors 222, 223, and 224 comprise more than 10 rotor teeth spaced circumferentially from the circumference of each rotor. In embodiments, stators 227, 228, and 229 comprise more than 10 stator teeth spaced circumferentially from the circumference of each rotor. In embodiments, the inner diameter of the rotor is about 12 cm. In embodiments, the diameter of the rotor is about 6 cm. In embodiments, the outer diameter of the stator is about 15 cm. In embodiments, the diameter of the stator is about 6.4 cm. In some embodiments the rotors have a diameter of 60 mm and the stators of 64 mm, providing a gap of about 4 mm. In certain embodiments, each of the three phases operates with a super fine generator, comprising a shear gap of between approximately 0.025mm and approximately 4mm. For applications where solid particles are sent through the high shear rate device 40, the appropriate shear gap width (minimum gap between rotor and stator) can be selected for appropriate particle size reduction and increase the surface area of ​​the particle. In embodiments, this can be beneficial in increasing the blooming of solid particles.

[0039] A high shear rate device 200 is configured to receive from line 13 a mixture at the inlet 205. The mixture comprises the treatment assistant as the dispersible phase and the water to be treated as the continuous phase. The flow

Feed ES 2 392 598 T3 will also typically comprise a solid particle component (eg, a contaminant). The feed stream accessing inlet 205 is pumped serially through generators 220, 230, and then 240, to form the product dispersion. The product dispersion exits the high shear rate device 200 through outlet 210 (and line 18 of FIG. 1). Rotors 222, 223, 224 of each generator rotate at a high speed relative to fixed stators 227, 228, 229, providing a high shear rate. The rotation of the rotors pumps the fluid, thus the feed flow accessing the inlet 205, outward through the shear gaps (and, if present, through the gaps between the rotor teeth and the gaps between stator teeth), creating a localized high shear rate condition. The high-velocity shear forces exerted on the fluid in shear gaps 225, 235, and 245 (and, if present, in the gaps between the rotor teeth and stator teeth) through which the fluid flows process the fluid and create a product dispersion. The product dispersion exits the high shear rate device 200 through outlet 210 (and line 18 of FIG. 1).

The product dispersion has a gas bubble, droplet, or average particle size of less than about 5 pm. In embodiments, HSD 40 produces a dispersion with an average bubble, droplet, and / or particle size of less than about 1.5 µm. In embodiments, HSD 40 produces a dispersion with an average bubble, droplet and / or particle size of less than 1 pm; preferably the bubbles, droplets or particles of the treatment aid have a diameter of submicrons. In certain cases, the average size of the bubble, droplet or particle is between about 0.1 pm and 1.0 pm. In embodiments, HSD 40 produces a dispersion with a mean bubble, droplet, or particle size of less than about 400 µm. In embodiments, HSD 40 produces a dispersion with an average bubble, droplet and / or particle size of less than 100 µm. High shear rate device 40 produces a dispersion comprising gas droplets, particles, and / or bubbles capable of remaining dispersed under atmospheric pressure for at least about 15 minutes. [0041] Not to be bound by theory, it is known in emulsion chemistry that submicron particles or bubbles dispersed in a liquid undergo motion primarily through Brown motion effects. Bubbles in the product dispersion created by the high shear rate device 200 may have greater mobility through the boundary layers of the particles.

ES 2 392 598 T3 solid contaminants, thus facilitating and accelerating the reaction / interaction through improved reagent transport.

In some cases, the high shear rate device 200 comprises a Dispax Reactor® reactor from IKA® Works, Inc. Wilmington, NC and APV North America, Inc. Wilmington, MA. There are several models available with various inlet / outlet connections, horsepower, peripheral speeds, output revolutions per minute, and flow rates. The selection of the high shear rate device will depend on the performance requirements and the desired particle, droplet or bubble size in the scattering line 18 (Figure 1) emerging through the outlet 210 of the high shear rate device 200. The IKA® DR 2000/4 model, for example, comprises a drive belt, a 4M generator, a polytetrafluoroethylene sealing ring, a 25.4 mm (1 inch) sanitary clamp inlet flange, an outlet flange 3/4 in. generator), a peripheral speed between 9.4 - 41 m / s (1850 ft / min to 8070 ft / min).

[0043] Container. The vessel or reactor 10 is any type of vessel in which the water treatment can be propagated. For example, a tank reactor with continuous or semi-continuous mixing tank, or one or more batch reactors can be used in series or in parallel. In some applications the container 10 can be a clarifier or any other type of separator. In embodiments, the container is an aeration tank. Any number of reactor inlet lines are envisioned, with two shown in Figure 1 (lines 14 and 18). Inlet line 14 may be an alkaline inlet line connected to container 10 to introduce a pH adjustment assistant during operation of the system. Container 10 may comprise an outlet line 17 for exhaust gas, and a product outlet line 16 for an aqueous stream. In embodiments, vessel 10 comprises a plurality of product lines from reactor 16; for example, if container 10 is a separator, the container may comprise an outlet for solids and an outlet for clarified water.

The treatment (for example aeration or chlorination) will be carried out when a suitable moment, temperature and pressure conditions exist. In this sense, the interaction of the pollutant and the treatment assistant, for example chemical oxidation, can occur at any point in the flow diagram of figure 1, if the contact is adequate. In embodiments, a significant reaction (for

ES 2 392 598 T3 example of chlorination) may occur within the HSD 40 and a separate container 10 may be unnecessary. That is, in some applications the container 10 can be omitted. For example, if multiple high shear rate devices / reactors are used in series or if the HSD 40 is used to aerate water prior to its introduction into an aeration pond, as described in more detail below, the vessel 10 may be absent. In such cases, the product from the HSD 40 can be introduced directly into the separator 30 or into a lagoon or aeration pond. The size of the reactor 10 can vary considerably, depending on the equipment and the amount of waste material to be processed in it.

[0045] Container 10 may include one or more of the following components: a mixing system, heating and / or cooling capabilities, instrumentation to measure pressure, instrumentation to measure temperature, one or more injection points, and a level regulator (not shown), as is known in the reaction vessel art. For example, a mixing system can include a motor driven mixer. A heating and / or cooling apparatus may comprise, for example, a heat exchanger.

[0046] Pumps. Pump 5 is configured for continuous or semi-continuous operation, and can be any suitable pumping device capable of providing controlled flow through HSD 40 and high shear rate system 1. In embodiments, the system is activated at or near atmospheric pressure. Pump 5 can be configured to provide a pressure greater than 202.65kPa (2 atm) or greater than 303,975 kPa (3 atm). For example, a Roper Type 1 gear pump, Roper Pump Company (Commerce Georgia) Dayton Pressure Booster Pump Model 2P372E, Dayton Electric Co (Niles, IL) is a suitable pump. Preferably, all contact parts of the pump comprise stainless steel, for example 316 stainless steel. In some embodiments of the system, the pump 5 reaches pressures greater than about 2026.5 kPa (20 atm). In addition to pump 5, one or more additional pumps (not shown) can be included in the system illustrated in Figure 1. For example, a charge pump, which can be similar to pump 5, can be included between the HSD 40 and vessel 10 to charge the pressure in vessel 10, or a recycle pump may be located in line 17 to recycle gas from vessel 10 to HSD 40. Another example may be a supplemental feed pump, which may be similar to pump 5, it may be included to introduce additional matter into container 10.

[0047] Separator. Separator 30 is a suitable container that can be configured

ES 2 392 598 T3 to separate treated water from a solid contaminant. Separator 30 can be, for example, a clarifier. In embodiments, the treated water is removed from below the floated solids in separator 30 through line 36, while in other embodiments, treated water is removed through line 33 above solids that have been allowed to settle on a bottom of separator 30.

[0048] Water treatment process. The operation of the high shear rate treatment system 1 will now be discussed with reference to aeration and chlorination.

[0049] Feed flow. Line 25 comprises water to be treated. The feed stream in line 25 can be a waste material, such as sewage or septic water from a small community or a factory. In embodiments, the feedwater comprises waste material from other sources, such as from the municipal treatment system, a waste discharge system from an industrial plant or a food processing facility, etc. In embodiments, a portion of the water in the inlet line 21 high-shear rate system comprises recycled water through line 45 from separator 30 or vessel 10. In embodiments, the water to be treated comprises raw water, eg surface or ground water that can be treated by eg chlorination through the published system and the process of disinfecting the water prior to use as drinking water. Such surface or ground raw water may comprise gas as normally occurs: hydrogen sulfide, gases produced through living organic matter such as algae, gases produced through the degradation of organic matter, residual chloride, and so on. The water can therefore be aerated , according to embodiments of the present publication, to facilitate the release of these gases. Such degassing from raw water can mitigate taste and / or odor problems prior to using the water as drinking water. In embodiments, the water is aerated and introduced into the aeration container 10 comprising microorganisms known to consume oxygen and organic matter in wastewater.

[0050] Pretreatment. In embodiments, wastewater enters a pretreatment device 60 through inlet line 25. For example, pretreatment device 60 may comprise a bar screen, a settling tank, or a filtration subsystem, known to those skilled in the art. The pretreatment device 60 may comprise, for example, a filter

ES 2 392 598 T3 bag. The pretreatment unit 60 can be configured to remove grease and / or large solids such as metal components in the water in line 25. The pretreatment discharge in line 26 comprises matter that should not be incorporated into the water in line 21 that is processed in the HSD 40.

[0051] Formation of the dispersion. Line 21 introduces water to be treated into pump 5. A gaseous dispersible treatment assistant comprising air, oxygen, or chloride or a dispersible treatment assistant liquid is introduced into system 1 through line 22, and is combined into the line 13 with the aqueous flow to be treated. In embodiments, the dispersible gas in line 22 comprises oxygen. In embodiments, the dispersible gas in line 22 comprises chloride. In embodiments, the dispersible gas in line 22 comprises air. In embodiments, line 22 comprises a dispersible treatment aid liquid (eg, a flocculant).

In embodiments, the dispersible treatment assistant is transmitted directly to HSD 40, rather than combining with the liquid flow of feed water in line 13. Pump 5 can be activated to pump liquid from the water feed source through line 21, can build pressure and feed HSD 40, and can provide controlled flow throughout the high shear rate device (HSD 40 ) and the high shear rate system 1. In some embodiments, the pump 5 increases the HSD inlet flow pressure to more than 200 kPa (2 atm) or to more than 300 kPa (3 atmospheres). In this regard, the high shear rate system 1 can combine the high shear rate with pressure to improve the intimate mixing of the water and the treatment assistant.

After pumping, the dispersible treatment assistant and the feed water to be treated are mixed in the HSD 40, which serves to create a fine dispersion (which can be, for example, a liquid / liquid emulsion or a dispersion gas / liquid) from the treatment assistant in the feed water. Within the HSD 40, the treatment assistant and feed water are highly dispersed so that the nanobubbles (nanodroplets), submicron sized bubbles (droplets), and / or the treatment assistant microbubbles (microdroplets) are formed to achieve superior dissolution improving solution and mixing. For example, the IKA® model DR 2000/4 disperser, a high shear rate device, with three dispersing phases configured with three rotors in combination with stators, aligned in series, can be used to create the treatment assistant dispersion in a liquid medium comprising feed water. The series of

ES 2 392 598 T3 rotor / stator can be configured as illustrated in Figure 2, for example. The combined reagents enter the high shear rate device through line 13 and enter a first phase of rotor / stator combination. The first stage rotors and stators may have circumferentially spaced first stage rotor teeth and stator teeth, respectively. The coarse dispersion exiting the first phase enters the second phase of the rotor / stator. The second stage rotor and stator may also comprise circumferentially spaced rotor teeth and stator teeth, respectively. The reduced size bubble or droplet dispersion emerging from the second phase enters the rotor / stator combination third phase, which may comprise a rotor and a stator with rotor teeth and stator teeth, respectively. The dispersion exits the high shear rate device through line 18. In some embodiments, the shear rate gradually increases longitudinally along the flow direction 260. For example, in some embodiments , the shear rate in the first rotor / stator phase is greater than the shear rate in the subsequent phase (s). In other embodiments, the shear rate is substantially constant along the flow direction, with the shear rate in each phase being substantially the same.

[0054] If the HSD 40 includes a polytetrafluoroethylene (PTFE) seal, the seal can be cooled using any suitable art recognized technique. For example, the feedwater stream in line 13 or line 21 can be used to cool the seal and to do this it is preheated before entering the high shear rate device 40.

[0055] The rotor or rotors of the HSD 40 may be set to rotate at a speed in proportion to the diameter of the rotor and the desired peripheral speed. As described above, the high shear rate device (for example the colloid mill or the serrated edge disperser) has a fixed gap between the stator and the rotor or has an adjustable gap. The HSD 40 serves to intimately mix the dispersible treatment assistant and feed water. In some embodiments of the process, the transport resistance of the reactants is reduced with activation of the high-shear rate device so that the reaction / interaction rate increases above about 5%. In some embodiments of the process, the resistance to transport of the reactants is reduced by using the high-shear rate device so that the reaction / interaction rate increases above a factor of 5.

ES 2 392 598 T3 approximately. In some embodiments, the reaction / interaction rate increases by at least a factor of 10. In some embodiments, the rate increases by a factor in the range of 10 to about 100.

In some embodiments, the HSD 40 emits at least 300 L / h at a peripheral speed of at least 22.9 m / s (4500 ft / min) and which can exceed 7900 ft / min (40 m / min). s). Power consumption can be about 1.5 kW. Although it is difficult to measure the instantaneous temperature and pressure at the tip of the rotating shear unit or rotating element of the HSD 40, it is estimated that the localized temperature of the fluid in it exceeds 500 ° C and the pressures exceed the 500kg / cm² under cavitation conditions. The high shear rate mixing results in a dispersible treatment assistant dispersion in micron or submicron sized bubbles or droplets. In some embodiments, the resulting dispersion has an average bubble or droplet smaller than about 1.5 µm in size. Accordingly, the dispersion exiting HSD 40 through line 18 comprises micron and / or submicron sized gas droplets or bubbles. In some embodiments, the mean bubble or droplet size is in the range between 0.4pm and 1.5pm. In some embodiments, the resulting dispersion has an average size bubble or droplet of less than 1 pm. In some embodiments, the average size of the bubble or droplet is less than 400 µm, and may be about 100 µm in some cases. In many embodiments, the dispersion is capable of remaining dispersed at atmospheric pressure for at least 15 minutes.

[0057] Once dispersed, the resulting gas / liquid / solid or liquid / liquid / solid dispersion exits HSD 40 through line 18 and fills container 10 as shown in Figure 1.

[0058] Chemical oxidation. The high shear rate system 1 can be used in a chloride oxidation wastewater treatment method. Chemical oxidation can disinfect or stabilize solid particles in water and produce partially water-free sludge. In these applications, the dispersible treatment assistant in line 22 comprises chloride gas for chemical oxidation of wastewater and the product dispersion in line 18 comprises chloride dispersed in a continuous aqueous phase. A portion of the dispersible gas in line 22 may comprise recycled chloride gas from any part of the system, for example, extracted from gas exiting container 10 through gas line 17. The dispersion can be introduced into container 10. As a result of intimate mixing

ES 2 392 598 T3 of the reagents before entering the vessel 10, a significant part of the chemical oxidation can occur in the HSD 40.

[0059] The introduction of the dispersible gas comprising chloride in line 22 of the water to be treated produces hypochlorous acid, which produces nascent oxygen and hypochlorite ions. Solid organic particles in water oxidize and form tiny bubbles of gas, including nitrogen and carbon dioxide, which can stick to the particles. The reaction between chloride gas and wastewater materials produces hydrochloric acid and hypochlorous acid. In the desired pH range (substantially neutral), more hypochlorous acid can be formed with the gaseous chloride than hydrochloric acid. Although hydrochloric acid (HCI) will not oxidize solid organic particles, it will aid disinfection. Hypochlorous acid (HOCI) as well as the hypochlorite ion, which is also formed by and with HOCI, are powerful oxidants. The pH can be controlled so that a sufficient amount of strong oxidants is present, particularly hypochlorous acid, which is the strongest oxidant present.

[0060] The pH of the wastewater can be altered by means known to those skilled in the art. For example, a pretreatment subsequent to pretreatment 60, a holding tank can be used to adjust the pH to a level that is close to neutral acid alkali, which is in the pH range of about 6.5 to 7.5 or more. preferably in the pH range between about 6.8 and 7.0. Wastewater is typically at a lower pH level than this, and therefore the addition of sodium hydroxide, lime or the like can be used in the high shear rate system 1 to raise the pH to the desired level. Conversely, if the residual matter is too alkaline, the pH can be lowered by adding water at a low pH or acid. In some embodiments, the pH adjustment material is added in another part of the high shear rate system 1, for example through the reactor inlet at line 14 or line 13. An adjustment pretreatment of the pH of the material to be treated introduced through line 21 can allow the formation of greater amounts of more effective oxidants, particularly hypochlorous acid. This can help stabilize residual solids.

The use of a substantially neutral pH level in a high shear rate system 1 may thus be desirable for the elimination of unpleasant odors and causes a greater degree of disinfection and / or stabilization of the resulting sediment. The use of the high shear rate system 40 can allow a more complete oxidation of the residual solid particles by improving the

ES 2 392 598 T3 contact of pollutants with the oxidant. When the process is activated in the desired pH range mentioned above, sufficient hypochlorous acid can be formed to effectively disinfect solid matters, that is, to destroy pathogens (e.g. bacteria and viruses, etc.) and to eliminate the growth of other bacteria.

[0062] In one embodiment, the wastewater material comprising particles of organic solids suspended in the water is treated by mixing the feed water completely with the chloride gas in the high shear rate device 40. The oxidation reactions between chloride and water stabilize and / or disinfect residual solid particles in other rotten and unstable ways. Chloride gas can be introduced into line 13 or directly into HSD 40. The amount of chloride introduced into the high shear rate system 1 will vary depending on the nature of the matter to be treated, the flow rate, etc. The dose of chloride can be between 700-3000 mg / l.

[0063] The dispersion in line 18 comprising chloride dispersed in a continuous phase of the water to be treated can be introduced into container 10. Inside container 10, the chemical oxidation reactions continue. The vessel / reactor 10 may operate in both a continuous and semi-continuous flow mode, or it may operate in a batch mode. The contents of vessel 10 can be maintained at a specific reaction temperature using heating and / or cooling capabilities (eg, cooling coils) and instrumentation to measure temperature. The pressure in the container can be monitored using suitable instrumentation to measure the pressure, and the level of reagents in the container can be controlled using a level regulator (not shown), employing techniques known to those skilled in the art. The contents can be mixed continuously or semi-continuously with a mechanical mixing apparatus, for example. Container 10 can operate at ambient temperature and atmospheric pressure. As mentioned above, sodium hydroxide or other alkali can be introduced through the inlet of line 14 to increase the pH when the pH of the feed water in line 25 is below the desired value.

[0064] Product gas and unconsumed chloride gas can exit vessel 10 through gas line 17. Unreacted treatment gas can be withdrawn from line 17 and recycled into HSD 40 or vessel 10, if desired. The temperature and pressure of the high shear rate system 1 vary depending on the feed flow, the type of oxidant used, and the mixing performed in the high shear rate device 40. Reactor 10 can be used under

ES 2 392 598 T3 pressure. Conditions of temperature, pressure, space velocity, and chloride gas ratio similar to those used in conventional water treatment can be employed. As an example, chemical oxidation can be used with a pressure in the range of about 200 kPa (30 psig) to 310 kPa (45 psig). In embodiments, chemical oxidation occurs at a pressure of approximately 240 kPa (35 psig). In embodiments, the oxidation is carried out at or near room temperature.

In the embodiment of Figure 1 the product emerges from container 10 through line 16. In embodiments, the product stream in line 16 comprises water and solids. The product in line 16 can be introduced into separator 30. The treated water is separated from the solids in separator 30. In embodiments the solids flocculate and float as a layer of sludge on the water and the treated water is extracted from the bottom of the separator 30. In said embodiments, line 35 can introduce a flocculating agent in line 16 to improve the flotation of the solid on the treated water and separation in separator 30. In another embodiment, the product in line 16 is introduced In separator 30, solids are allowed to settle to the bottom of separator 30, and the treated water is drawn through line 33 from the top of separator 30. In embodiments, the treated water is further processed, for example the pH of the treated water can be adjusted. A part of the treated water can be recycled to HSD 40 through, for example, line 45. Such recycle of the treated water can be used to adjust the pH of the water in line 21. The solids separated from the treated water as sludge in the spacer 30 can be pulled out for disposal.

The resulting treated solid waste matter separated from the treated water in separator 30 may be at least 99% disinfected, alternatively 99.9%. The production of unpleasant odors can be minimized and / or the sludge separated from the treated water can be sufficiently disinfected or stabilized that it can be used as fertilizer material or can be applied as a plant cover. The high shear rate system and method of water treatment can produce a sediment that is equivalent to a so-called pathogen further reducing process (also called PFRP) in which substantially all bacteria and pathogens within the matter are destroyed.

[0067] Multi-pass operation. In the embodiment shown in Figure 1, the system is configured for a single pass operation, in which the outlet 16 of the vessel 10 is used directly for further processing of the recovered treated water. In some embodiments it may be desirable to pass the

ES 2 392 598 T3 contained by container 10, or a liquid fraction thereof, through HSD 40 during a second pass. In this case, line 16, line 33, or line 36 can be connected to line 21 for example through line 45, whereby at least a part of the contents of the line is recycled from container 10 or separator 30 and are pumped by pump 5 towards line 13 and therefore towards HSD 40. Additional treatment gas can be injected through line 22 into line 13 or can be added directly to the high shear rate device (not shown).

[0068] Multiple high shear rate mixing devices. In some embodiments, two or more high shear rate devices such as the HSD 40, or configured differently, are aligned in series, and are used to further improve water treatment. The use of multiple HSDs can be in both batch and continuous mode. In some cases where a single pass or crossover process is desired, the use of multiple high shear rate devices in series may also be advantageous. In some embodiments where multiple high shear rate devices are used in series, the container 10 may be omitted. For example, in embodiments, the dispersion emerging from line 18 may be introduced into a second high shear rate device and subsequently into any number of additional high rate shear devices or into separator 30 or into a pond or aeration lagoon. When the multiple high shear rate devices 40 are used in series, an additional treatment gas can be injected into the feed stream inlet of each device. In some embodiments, the multiple high-shear rate devices 40 operate in parallel, and the dispersions emerging from it are introduced into one or more vessels 10. In other embodiments, the multiple high shear rate devices 40 operate in parallel, and the dispersions emerging from it are introduced into one or more aeration separators 30, ponds, or lagoons.

[0069] Features. Without wishing to be bound by a particular theory, it is believed that the level or degree of high shear rate mixing is sufficient to increase mass transfer rates and also produces non-ideal localized conditions that allow a reaction / interaction to occur that it could not be expected to happen otherwise based on Gibbs free energy predictions. Non-ideal localized conditions are considered to occur within the high shear rate device resulting in

ES 2 392 598 T3 increased temperatures and pressures considering that the most significant increase is in localized pressures. The rise in pressures and temperatures within the high-speed shear device is instantaneous and localized and quickly returns to average conditions once outside the high-speed shear device. In some cases, the high shear rate mixing device induces cavitation with sufficient intensity to dissociate one or more of the reactants into free radicals, which can enhance a chemical reaction / interaction or allow a reaction to occur under conditions less stringent than would otherwise be required. Cavitation can also increase the speed of transport processes by producing local turbulence and liquid microcirculation (acoustic current). An overview of the application of the cavitation phenomenon in chemical / physical processing applications is provided by Gogate et al., Cavitation: A technology on the horizon, Current Science 91 (No.1): 35-46 (2006). The high shear rate mixing device of some embodiments and methods of the present system induces cavitation whereby the treatment assistant and the contaminant dissociate into free radicals, which then interact.

[0070] Present methods for treating water incorporate an external high shear rate mechanical device to provide rapid contacting and mixing of chemical ingredients in a controlled environment in the high shear rate reactor / device. The high shear rate device reduces the mass transfer limitations on the reaction / interaction and thus increases the overall reaction / interaction rate, and can allow a substantial reaction under the overall operating conditions under which the substantial reaction it may not be expected to occur.

[0071] In embodiments, the use of the published process comprising mixing through the high shear rate device 40 allows greater production (higher throughput) than that of the process operating without the high shear rate device 40. In embodiments, the consumption of treatment chloride gas, and / or flocculant liquid are reduced compared to water treatment without a high shear rate device 40.

[0072] In embodiments, the method of this publication allows the design of a smaller and / or less capital intensive process allowing the selection of a reactor 10 (and / or a tank 30) with a smaller volume than the previously possible without incorporation of an external high shear rate device 40. In embodiments, the published method reduces the costs of

ES 2 392 598 T3 operation / increases the production of an existing process. Alternatively, the published method can reduce capital costs for new process design.

[0073] Potential benefits of the high shear rate system include, but are not limited to, faster cycle times, improved performance, reduced operating costs, and / or reduced capital expenditure due to the possibility of designing more vessels. little ones. In embodiments, the process of the present publication provides a higher level of contaminant removal during water treatment compared to conventional water treatment processes comprising the absence of a high shear rate external mixer. In embodiments, the degree of mixing in the external high shear rate device 40 is varied to achieve the desired level of removal of a specific contaminant. In embodiments, the water treatment high shear rate process of the present publication reduces the use of treatment gas (eg, chloride, oxygen, air).

In embodiments, the use of the present method for water treatment makes the use of reduced amounts of chloride economically feasible, by increasing the rate of oxidation of the contaminant, etc.