The present disclosure is generally related to liquid treatment methods, devices, and systems and more particularly is related to liquid treatment methods, devices, and systems (such as water treatment methods, devices, and systems) that use mixing chambers for facilitating removal of contaminants by coagulation and precipitation.
Communities and industries today are faced with meeting more stringent regulations for treating and disposing of their wastewater. Recent decisions by the Environmental Protection Agency (EPA) tighten the maximum allowed contamination levels for discharging wastewater containing aluminum, copper, phosphates, and nitrogen-containing bio nutrients to the estuaries, lakes, and inter-coastal waterways, which may result in increased water treatment costs.
There are many commercially available applications and technologies today for removing trace and heavy metals, organic compounds, and bio nutrients such as phosphates, nitrates, nitrites, and ammonia from municipal and industrial water supplies and wastewater streams. Among the available technologies are coagulation and precipitation processes, oxidative medias (such as green sand, granulated ferric hydroxides, etc.), lime softening, dissolved air filtration (“DAF”), biological processes, activated alumina, zeolites, ion exchange resins, cartridge filters, reverse osmosis (“RO”), and membranes.
Some communities (e.g., municipalities) and industries treat or pre-treat process waters and wastewater streams using a single technology with some type of clarification or filtration devices for removing the contaminants and solids formed in the water treatment process. Other communities and industries use a combination of technologies such as coagulation and precipitation for process waters and membrane technologies for removing contaminants to meet locally regulated discharge permits into streams, rivers, ponds, lakes, or inter-coastal waterways. The chemical and operating costs of clarifiers, membranes, and other filtration equipment required to meet federal and state clean water regulations amount to billions of dollars annually worldwide.
Despite the cost, most municipal and industrial water treatment facilities still utilize coagulation and precipitation technologies for removing suspended and dissolved contaminants in the water supply. The chemicals and coagulants used in the precipitation process are selected depending upon the source of the water and the type of contaminants requiring removal. Alum, aluminum chlorides, poly aluminum chlorides, lime, ferric sulfate, ferric chloride, potassium permanganate, potassium hydroxide, and sodium hypochlorite are among the more prevalent chemicals, coagulants, and oxidizers used in the water treatment industry today.
Referring to
Referring to
Some municipal wastewater treatment plants use digestion processes to break down organic contaminants. In such processes, aluminum sulfates and ploy-aluminum chlorides are injected to remove phosphorus and control other metals. To meet reduced EPA phosphorous level requirements, some communities have added additional aluminum. However, the amount of residual aluminum allowed in wastewater is also under scrutiny and is now posing a problem for the user as well as the manufacturers of aluminum-based coagulants.
The effectiveness of mixing chemical coagulants and oxidants to coagulate and precipitate contaminants in water has been a subject that has been openly debated and discussed in many water treatment forums and publications. Laboratory work performed by state and federal regulatory agencies, engineering firms, and manufacturers of static, cavitation, rapid, or flash mixing devices and systems confirm that mixing and temperature play an important role in the coagulation, oxidation, and precipitation removal of trace and heavy metals in contaminated industrial and municipal drinking water and wastewater streams. However, the type of mixing and the time required to coagulate and precipitate contaminants still remains a contested subject.
Static mixers include a series of geometric mixing elements that have been fixed within a pipe that uses the energy of the liquid or gaseous streams to blend or mix two or more gases and liquids with minimal pressure loss. Some static mixers create high shear forces that damage polymers that are designed to perform a flocculation (i.e., to form precipitates). In water treatment applications, the flocculating ability of the polymer is fragile, and high speeds or heavy shearing will reduce the ability of the polymer to flocculate. In water treatment applications, a controlled amount of mixing can provide improved precipitates and analytical results.
Other mixers include low or high speed motors with shafts and propellers. At high speed operations, propeller type mixers can add unwanted air and foaming to a tank or even create irreversible emulsions. Propeller type mixers are useful in some applications, but overall are not effective in many applications where a complete dispersion of liquid components is required.
One of the most effective known methods of mixing occurs when two or more liquids are gently stirred clockwise and then the stirring motion is changed to counterclockwise. As this is repeated, hot liquids cool faster and liquids blend more effectively as the vortex created by the stirring shifts from a clockwise to a counter clockwise motion. Many static mixing devices are formed in an attempt to duplicate such a stirring action by placing geometric elements in configurations that will roll the liquids together. However, improvements in static mixing devices are desired.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
Embodiments of the present disclosure provide a mixing chamber system for removal of contaminants from a liquid. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. A length of pipe has a hollow interior. A plurality of perforated discs are stationarily positioned within the hollow interior in at least a portion of the length of pipe, wherein each of the plurality of perforated discs has a curved profile, wherein a middle portion of each of the plurality of perforated discs is offset from a radial edge of each of the plurality of perforated discs, respectively.
The present disclosure can also be viewed as providing a system for removal of contaminants from a liquid. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. A quantity of liquid is carried in an inlet. In a preliminary treatment station, a plurality of organic material is removed from the quantity of liquid. A mixing chamber is in fluid communication with the preliminary treatment station, wherein a quantity of precipitate is separated from the quantity of liquid within the mixing chamber, wherein the mixing chamber comprising: a length of pipe having a hollow interior; and a plurality of perforated discs stationarily positioned within the hollow interior in at least a portion of the length of pipe, wherein each of the plurality of perforated discs has a curved profile, wherein a middle portion of each of the plurality of perforated discs is offset from a radial edge of each of the plurality of perforated discs, respectively. A secondary filter system receives the quantity of water and the quantity of separated precipitate from the mixing chamber, wherein the quantity of separated precipitate is removed from the quantity of water. A chemical treatment system receives the quantity of water from the secondary filter system.
The present disclosure can also be viewed as providing method for removing contaminants from a liquid. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: removing a plurality of organic material from a quantity of liquid within a preliminary treatment station; separating a quantity of precipitate from the quantity of liquid within a mixing chamber in fluid communication with the preliminary treatment station, whereby the quantity of precipitate and the quantity of liquid flow through a plurality of perforated discs stationarily positioned within a hollow interior in at least a portion of a length of pipe, wherein each of the plurality of perforated discs has a curved profile, wherein a middle portion of each of the plurality of perforated discs is offset from a radial edge of each of the plurality of perforated discs, respectively; filtering the quantity of water and the quantity of separated precipitate within a secondary filter system in fluid communication with the mixing chamber, wherein the quantity of separated precipitate is removed from the quantity of water; and chemically treating the quantity of water after the secondary filter system.
Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The following description provides specific details in order to provide a thorough description of embodiments of the present disclosure. However, a person of ordinary skill in the art will understand that the embodiments of the present disclosure may be practiced without employing these specific details. Indeed, the embodiments of the present disclosure may be practiced in conjunction with conventional techniques employed in the industry.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable a person of ordinary skill in the art to practice the present disclosure. However, other embodiments may be utilized and structural and methodological changes may be made without departing from the scope of the disclosure. The illustrations presented herein are not meant to be actual views of any particular system, device, structure, or method, but are merely idealized representations which are employed to describe the embodiments of the present disclosure. The drawings presented herein are not necessarily drawn to scale. Additionally, elements common between drawings may retain the same or similar numerical designation. However, any similarity in numbering does not mean that the structures or components are necessarily identical in size, composition, configuration, or other property.
As used herein, the term “substantially” in reference to a given parameter means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. By way of example and not limitation, a parameter that is “substantially” met may be at least about 90% met, at least about 95% met, or even at least about 99% met.
As used herein, the phrase “coagulation and precipitation” means and includes any type of oxidation-reduction reaction using oxidizers, coagulants, and/or flocculating agents to treat a contaminated liquid by forming a precipitate including one or more contaminants, to enable the one or more contaminants to be separated from the liquid by clarification and/or filtration.
As used herein, the term “contaminant” refers to any substance suspended or dissolved in an aqueous or non-aqueous liquid that affects the purity of the liquid.
Embodiments of the present disclosure include methods and systems for liquid (e.g., water) treatment that include coagulation and precipitation processes. For example, mixing chambers and components thereof maybe used to produce highly adsorptive particles for increasing an efficiency of coagulation and precipitation processes. The mixing chambers may include a plurality of curved, perforated discs positioned internally along a length of a pipe. In some embodiments, the curvature of adjacent discs may alternate. In some embodiments, the discs may be configured to be fixed relative to the pipe. Thus, the mixing chambers of the present disclosure may not use any external power source (e.g., electricity, hydraulic power). The mixing of liquid passing through the mixing chambers may be enhanced due to turbulence and back-and-forth flow caused by the geometry and configuration of the discs. Accordingly, the coagulation and precipitation process using the mixing chambers of the present disclosure may have increased efficiency compared to conventional systems, and an amount of chemicals used in coagulation and precipitation processes may be reduced to treat similarly contaminated liquid.
The discs 204 may be positioned in a fixed location relative to the pipe 202, and may be configured to not rotate or otherwise move relative to the pipe 202. Accordingly, no external power (e.g., electrical or hydraulic power) may be required to operate the mixing chamber 200, other than the power used to flow the liquid through the mixing chamber 200 (which may be provided by gravity, a pump, or a combination thereof, for example). In addition, the mixing chamber 200 may include no moving parts, and may be characterized as a “static” mixing chamber 200. In other embodiments, the discs 204 may be rotated about an axis through which the rod 206 extends and/or moved back and forth along the axis through which the rod 206 extends, if desired for a particular application.
As shown in
Referring to
Referring to
During operation, a liquid (such as water) may flow into the inlet of the mixing chamber 200, as shown by arrows 208 in
The mixing chamber 200 of the present disclosure may also enable the formation of precipitates that have a smaller particle size than previously known mixing chambers. Smaller precipitates have a greater surface area per mass of precipitate. The greater surface area may enable adsorption of additional contaminants, and less precipitate may be necessary to remove an equal amount of contamination from a liquid compared to larger precipitates. By way of example, precipitates formed in previously known mixing chambers may have a diameter of about 50 microns or more, while precipitates formed by the mixing chamber 200 of the present disclosure may have an average diameter of less than about 5 microns, in some embodiments. To illustrate the increased surface area of smaller precipitates, the surface area to volume ratio of a sphere (approximating a shape of the precipitates for illustrative purposes) is proportional to the reciprocal of the diameter of the sphere. Thus, if the diameter of a small sphere is ten times smaller than a larger sphere, then the surface area to volume ratio may be about ten times greater than the larger sphere. Thus, the mixing chamber 200 including the curved discs 204 may form precipitates with higher surface area to volume ratios, which may significantly enhance surface adsorbing capacities of precipitates of a given mass.
In some embodiments, oxygen may be introduced into the liquid at an inlet side of the mixing chamber 200 to facilitate the breakdown of organic materials into carbon dioxide and water. The discs 204 may enhance oxidation of contaminants, such as organic material. Air or oxygen bubbles may be efficiently mixed and dissolved into the liquid matrix at a relatively higher ratio of dissolved oxygen in the liquid compared to prior known mixers. The increased oxygen ratio may make more oxygen available for further oxidation, which may reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD) requirements for breaking down organic contaminants.
In the surface water treatment system 300 of
As described above, water leaving the mixing chamber 200 may enter a gravity filter 309 to remove precipitates. The gravity filter 309 may include sand, such as red garnet sand, to filter out the precipitates. Then, the water may enter a clear well 310. The water may be further treated by ultraviolet light and/or chlorination 311. A storage holding tank 312 may hold the water until it is pumped 313 to a storage tower 314 and/or a community distribution system 315, as described above.
As the flash mixing chamber 6, the flocculation tank 7, and the sediment basin 8 are replaced with the mixing chamber 200, which may be physically smaller than the flash mixing chamber 6, the flocculation tank 7, and the sediment basin 8, the surface water treatment system 300 may have a smaller footprint than the conventional system. In addition, capital expenditures and maintenance costs for specialized tanks, electric motors, and mixing paddles/propellers may be reduced, such as by more than 50%.
In the well water treatment system 400 of
Thus, the present disclosure includes methods of creating highly adsorptive precipitates including (a) admixing contaminated wastewater with an effective amount of ferric chloride as a coagulating agent and an effective amount of an oxidizing agent to raise the oxidation state of metals and contaminants and accelerate the formation of a precipitate; (b) introducing said mixture under pressure into a reaction/mixing vessel containing a stainless steel or other non-corrosive material configured such that the flow path of the mixture is continuously, kinetically mixed without losing a significant amount of head pressure, thus assuring that all contaminants in the mixture have been contacted by the chemical coagulating and precipitating agents; (c) subjecting the mixture inside the kinetic flow path of the reaction vessels so that the forming precipitate is under shear, dividing the contaminant laden and non-laden precipitate into millions of smaller particles with massive surface areas that effectively adsorb more contaminants; and (d) separating the flocculated precipitates from the water phase with sand filtration. The reaction/mixing vessel may include curved, perforated discs through which the mixture flows, and the curved, perforated discs may have alternating curvatures.
Although the mixing chambers, systems, and methods of the present disclosure have been generally described in the context of water treatment, the disclosure is not limited to water treatment applications. For example, the mixing chamber 200 and systems 300 and 400 may be used for treating any liquid, whether aqueous or non-aqueous. By way of another example, the mixing chamber 200 may be used in mixing processes other than coagulation and precipitation processes, such as in processes for mixing any two liquids, a solute into a solvent, or particles into a liquid. Additional uses for the mixing chambers, systems, and/or methods of the present disclosure will be apparent to one of ordinary skill in the art upon consideration of the present disclosure. Such additional uses and applications are also included in the present disclosure.
The present invention incorporates the benefits of controlled mixing in aqueous or non-aqueous solutions by gently moving two or more liquids in forward and reverse motions (i.e., in eddies formed when liquids pass through the configuration of the mixing chamber 200 and its components) so that the turbulent motions blend, stir, and mix the liquids into a substantially homogeneous mixture, whether large or small volumes of liquid are treated. The motion of the liquids also provides a sustained kinetic energy, which may accelerate the reaction time of contaminated liquids to form a precipitate within the mixing chamber, so that sediment or settling tanks are eliminated.
The methods, systems, and devices of the present disclosure may be used to admix coagulants, oxidizers, polymers, and pH adjusting chemicals with contaminated aqueous or non-aqueous solutions requiring low contamination levels (after treatment), as mandated by regulatory agencies, without the assistance of utility power.
The methods, systems, and devices of the present disclosure may also be used to admix large or small volumes of water at low or high pressures with various water treatment chemicals at reduced dosage rates, which may create a highly adsorptive precipitate that can be separated in a multimedia filter without the use of a sediment basin.
Without being bound by theory, the methods, systems, and devices of the present disclosure may also incorporate the motion of the liquids and their transfer path to create a shear force on the precipitates formed in the oxidation-reduction action. Such a shear force may be sufficient to create millions of small particles with highly adsorptive surface areas. These particles may instantly flocculate within or upon leaving the mixing chamber, which may facilitate the separation of the contaminants from the liquid.
A particular embodiment of the device can create nano sized particles (e.g., <0.2 microns) under low to high pressures. These particles can recombine to form precipitates greater than 50 microns (50,000 nm), improving separation of the solids from water by conventional means. Another embodiment relates to a system for blending and mixing coagulants, polymers and oxidizing agents into contaminated water for improved separation, coagulation and separation of the solids from the water phase. Embodiments of the device for improve the oxidation of water from an outside source of air through cavitation of the movement of water in the flow path. By changing the configuration of the concave/convex discs, and the angle of flow in the discs, cavitation and temperature can be increased, thus increasing the kinetic energy of the process of coagulation and the breakdown of organic compounds.
Particular embodiments of the device improve the removal of phosphorus in wastewater systems to less than 30 ppb. Other embodiments of the device are designed for blending chemicals in non-aqueous solutions.
Particular embodiments of the device can improve the removal of colloidal suspensions in aqueous and non-aqueous solutions. Other devices and methods are designed to improve the removal of total suspended solids by precipitation in aqueous solutions. Some embodiments of the method and device can remove up to 26 metals in a single process. Certain embodiments of the method and device may work in pH ranges from 4.0 to 9.5 without the use of pH adjusting chemicals.
Alternative embodiments of the system and method are designed for eliminating settling tanks and basins, reducing capital expenditures. An alternative system can be designed to eliminate rapid mix, flash and other static mixing devices. The systems and methods can be designed to generate superior removal of contaminants
The embodiments of the disclosure described above and illustrated in the accompanying drawing figures do not limit the scope of the invention, since these embodiments are merely examples of embodiments of the disclosure. The invention is defined by the appended claims and their legal equivalents. Any equivalent embodiments lie within the scope of this disclosure. Indeed, various modifications of the present disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements described, will become apparent to those of ordinary skill in the art from the description. Such modifications and embodiments also fall within the scope of the appended claims and their legal equivalents.
This application claims benefit of U.S. Provisional Application Ser. No. 61/768,278 entitled, “Methods, Devices, And Systems for Creating Highly Adsorptive Precipitates” filed on Feb. 22, 2013, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
61768278 | Feb 2013 | US |