Abstract
The present invention relates to a new and novel process that combines treatment methods that use magnetite, Hydrothermal Carbonization (HTC), Hydrodynamic Cavitation (HDC), probiotics, and adsorption using Magnetic Hydrochar (MHC) and Water Treatment Residuals (WTR) to replace Activated Sludge Technology (AST) for the treatment of wastewater containing dissolved organic and inorganic contaminants.
Claims
1. A method for purifying water, comprising the steps of: providing a select probiotic production system, for growing probiotics useful in treating organic contaminants in water, wherein said probiotics are grown using lysed and disinfected biosolids or other organic wastes as food for the probiotics; providing a pipeline for supplying said probiotics to the stream of water at a given location; employing a magnetic high rate clarifier (MHRC), downstream of said given location, for attaching magnetite particles to dissolved and suspended solids in the water using a flocculating polymer to form a magnetic floc, and for subsequently removing said magnetic floc from the water employing a magnetic attraction technique, leaving an effluent water stream; providing a hydrothermal carbonization (HTC) system, wherein the removed magnetite particles and dissolved and suspended solids are processed to yield a magnetic hydrochar material that is high in carbon and is a useful adsorbent that is used to treat the stream of water in its conveyance system; employing a disinfecting system wherein the effluent water stream from the MHRC is disinfected and discharged for use; and lysing and disinfecting solid organic wastes, so as to serve as food for growing probiotics.
2. The method of claim 1, wherein the biosolids from a sewage treatment plant or other organic wastes employed to grow probiotics are disinfected and lysed by methods including mechanical, thermal, electrical, sonic methods, and hydrodynamic cavitation, to kill competing microorganisms, including pathogenic bacteria and sulfur reducing bacteria (SRB) and to increase the food value of the organic wastes by releasing the cell protoplasm contents beneficial for growing the probiotics.
3. The method of claim 1, wherein the organic wastes that have been disinfected and lysed to make suitable for growing probiotics includes biosolids from a sewage treatment plant, septage, grease trap wastes, and food wastes.
4. The method of claim 1, wherein an adjustable flow control device in said water conveyance system is provided to control the accumulation of water within the conveyance system, so as to control the residence time of water in the conveyance system,.
5. The method of claim 1, wherein the probiotics contain bacillus bacteria selected from the group consisting of B. Subtiles, B. Licheniformes, B. Indicus, B. Coagulans, B. Cereus, and B. Clausii.
8. The method of claim 1, wherein the conveyance system may be a pipeline, canal, or a natural watercourse that may be extended by a man-made canal or other conveyance system added alongside or within a river or stream to increase the residence time so biological treatment can continue to treat water before it enters a river or stream.
7. The method of claim 4, wherein the flow control device comprises an adjustable weir so as to create either a smaller reservoir of water during dry weather conditions or a larger reservoir of water during wet weather conditions, allowing control of the residence time of the water in the reservoir to provide time for the probiotics to treat the water to desired levels.
8. The method of claim 1, wherein process liquids from HTC are used to grow probiotics or as a source of organic fertilizer.
9. The method of claim 1, wherein magnetic floc from a MHRC is hydrothermally carbonized in a HTC to produce magnetic hydrochar.
10. The method of claim 1, comprising the further steps of screening floatables before said MHRC step and disinfection after said MHRC.
11. The method of claim 1, wherein the MHRC removes fine suspended solids including bacteria and other microorganisms by the use of an anionic or cationic flocculating polymer and/or coagulant.
12. The method of claim 1, wherein the MHRC has a surface overflow rate greater than 10 gallons per minute per square foot.
13. The method of claim 1, wherein solids removed by MHRC are diverted into one or more containment structures that are either positioned in a riverbed that increases the biological treatment time or pumped to a nearby waste water treatment plant (WWTP) for further clarification, biological, and dewatering treatment.
14. The method of claim 1, wherein probiotics that have been removed by a MHRC are routed to a probiotic grow system to provide a constant source of probiotics to enhance the performance of the WWTP, to treat water upstream in the conveyance system, and also downstream of the WWTP to improve river water quality.
15. The method of claim 1, wherein the surface charge on the magnetite used in the MHRC is modified using chemicals or controlling pH so the magnetite acts as a reusable chemical coagulant to neutralize the charge on TSS and thus eliminates the use of chemical coagulants.
16. The method in claim 1, wherein said adsorbents include magnetite, MLSS, carbon and chemical based adsorbents, and water treatment residuals produced from the treatment of drinking water.
17. The method in claim 1, wherein the adsorbents are either macrosized greater than 5 microns or microsized such as nano particles.
18. The method in claim 1, wherein the adsorbents have been functionalized by chemical, thermal, or mechanical means to modify the surface of the adsorbent to selectively adsorb dissolved contaminants contained in water.
19. The method in claim 1, wherein the magnetic floc from MHRC is used in the production of fired brick.
20. The method in claim 1, wherein the pipeline used to deliver the probiotics upstream into the water conveyance system is installed inside the conveyance system or above ground.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0127] Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and with reference to the accompanying drawings, in which:
[0128] FIG. 1 shows an overview of the treatment technologies employed in a novel way according to the invention and how MHRC, HTC, WTR, biological agents, and MHC are integrated either separately or individually into one system that economically treats wastewater.
[0129] FIG. 2 shows the details of a Biological Grow System that uses “process liquids” from HTC and organic waste solids to produce biological agents herein also referred to as probiotics.
[0130] FIG. 3 shows a first embodiment of a Magnetic High Rate Clarifier (MHRC) for removing magnetic floc, which is composed of TSS, magnetite, and flocculating polymer to remove suspended solids from water using permanent magnets.
[0131] FIG. 4 shows a second embodiment of a Magnetic High Rate Clarifier (MHRC) for removing magnetic floc, which is composed of TSS, magnetite, and flocculating polymer to remove suspended solids from water using gravity.
[0132] FIG. 5 shows a system for using Water Treatment Residues (WTR), MHC, magnetic floc from MHRC, and probiotics to treat wastewater in a conveyance system and to improve the operating conditions in the wastewater conveyance system, followed by clarification using MHRC to produce a magnetic floc that is used in brick production and as a feedstock to HTC to produce MHC.
[0133] FIG. 6 shows an alternative process to treat wastewater using MHRC for clarification and Hydrodynamic Cavitation (HDC) to treat the magnetic floc produced from MHRC and to dewater the magnetic floc with a reed bed to produce solid organic fertilizer and nutrient rich liquids, which may be used to grow probiotics in turn used to treat wastewater in the wastewater conveyance system.
[0134] FIG. 7a shows a typical state of the art WWTP using AST that includes clarification, biological treatment, and disinfection.
[0135] FIG. 7b shows a comparison system to AST according to this invention that uses MHRC for clarification and HDC to process magnetic floc from MHRC to grow probiotics and reduce the particle size of magnetite so they can be used in-line in the conveyance system to treat sewage.
[0136] FIG. 8 shows an overview of the treatment technologies employed according to the invention and how they are integrated to produce the desired result of economically treating wastewater.
[0137] FIG. 9, comprising FIGS. 9(a) and 9(b), shows a flow control device that can be adjusted to change the pool level in the conveyance system, which will vary the holding capacity of the conveyance system.
[0138] FIG. 10 shows the extension of a wastewater conveyance system and its placement inside a riverbed.
[0139] FIG. 11 shows a delivery system that takes select microorganisms grown at a WWTP and transports the select microorganisms either through a pipeline placed within the wastewater conveyance system upstream of the WWTP or into the effluent of the WWTP.
DETAILED DESCRIPTION OF THE INVENTION
[0140] While this invention is susceptible to implementation in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure of such embodiments is to be considered as an example of the principles of the invention, and is not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings. This detailed description defines the meaning of the terms used herein and specifically describes embodiments in order for those skilled in the art to practice the invention.
[0141] FIG. 1 shows a wastewater treatment system according to the invention, wherein a stream of wastewater (1) that has been treated in-line by the addition either combined or separately of MHC (16), MLSS (20), WTR (22), and probiotics (15) flows into a Magnetic High Rate Clarifier (MHRC) (3) (different embodiments of which are detailed in FIGS. 3 and 4) where treated water that contains TSS is combined with a flocculating polymer (4) and magnetite (5) to form a magnetic floc (7) composed of magnetite (5), polymer (4) and TSS including organic solids, WTR, MHC, and biological agents such as probiotics. The floc is separated from the cleaned water in the MHRC (3) as described in detail below with respect to FIGS. 3 and 4. The clarified water (6) is discharged and the separated magnetic floc (7) flows to a Hydrothermal Carbonizer (HTC) (8). Magnetic floc (7) discharged (21) from the MHRC can also be used in the production of bricks as shown in FIG. 5 or be supplied to a HDC as shown in FIG. 6. The HTC (8) performs a thermochemical process used to convert wet biomass such as sewage biosolids into a solid product called HydroChar (HC). The HTC (8) employs pressurized water at relatively low temperatures between 180 degrees centigrade and 250 degrees centigrade and at or below saturated pressure. The HTC process mainly entails decarboxylation, dehydration, and polymerization. Removing carboxyl and hydroxyl groups reduces the oxygen to carbon ratio, which makes the HC more carbon-dense and therefore more suitable as a solid fuel or as an adsorbent. The HTC (8) also produces “process liquids” that are high in nutrients, especially phosphorus, that can be recovered. If the HC produced by HTC (8) contains magnetite, the product is termed Magnetic Hydrochar (MHC). Other sources of organic wastes (9) such as food waste, grease trap waste, WWTP biosolids, septage or animal waste can also be processed in the HTC (8) to increase the carbon to magnetite ratio of the MHC. The preferred ratio of carbon to magnetic material in MHC is 2:1. Special additives such as iron or other catalysts (10) can be added to the HTC (8) to improve the adsorption properties of MHC. MHC and “process liquids” (11) flow from the HTC (8) into a separator (12) that separates MHC (16), preferably by gravity, from the “process liquids” (13). A slurry of MHC (16) is pumped into a pipeline (19) that is preferably placed inside the wastewater conveyance system (2). The “process liquids” (13) flow from the Separator (12) into a Biological Grow System (14), detailed in FIG. 2, that grows probiotics and other microorganisms with the nutrients contained in the “process liquids” (13). Biological agents (15) containing probiotics and other microorganisms grown in the Biological Grow System (14) may combine with MLSS (20) from a WWTP or WTR (22) in a pipeline (17) that connects to a pipeline (18) that is also placed inside the wastewater conveyance system (2). The purpose of this combined flow of biological agents (15), MLSS (20), and WTR (22) either separately or combined is to adsorb and biologically treat DC flowing (1) in the wastewater conveyance system (2), which essentially converts the wastewater conveyance system into a wastewater pretreatment system.
[0142] FIG. 2 shows the details of the Biological Grow System (14) shown in FIG. 1 for growing biological agents (15), comprised primarily of bacteria and phages, to biologically treat wastewater inside a wastewater conveyance system. Organic waste (23), specifically, solid organic wastes (i.e. food waste, WWTP biosolids, septage, animal waste, or grease trap waste), are mixed in a Macerator (24) designed to blend and make homogeneous the organic wastes (23). This homogeneous product (29) combines with “process liquids” (13) from a HTC (8) and flows to a Disinfector (25), more specifically a Hydrodynamic Cavitation (HDC) system that uses collapsing microbubbles to disinfect organic wastes (29) so that pathogens contained therein do not compete with the growth of the microorganisms in the Biological Grow Tank (28). The organic wastes (23) and HTC “process liquids” (13) that have been treated in the Disinfector (25) then flow into a Recirculation Tank (27) and are returned using a Pump (26) back to the Disinfector (25) to allow the organic wastes to be lysed and disinfected multiple times. Once the organic cells have been suitably disinfected to remove pathogens and have been lysed to release additional liquid nutrients, the treated organic wastes flow to a Biological Grow Tank (28) to feed a mixture of microorganisms, preferably facultative bacillus bacteria and phages as discussed above. These microorganisms (15), then flow through a pipeline (17-FIG. 1) into the wastewater conveyance system (2-FIG. 1).
[0143] FIG. 3 shows the details of a first embodiment of a Magnetic High Rate Clarifier (MHRC) that uses permanent magnets as a final filter to prevent the discharge of magnetic floc, and to allow recovery of the magnetite for reuse. Wastewater (1) that that has been pretreated in-line to adsorb and biologically remove DC flows into a MHRC tank (31). Polymer (32) and magnetite (33) are added to the MHRC tank (31) and agitated with a motor (34) and mixer blade (35) to cause a magnetic floc (38) to form. The magnetic floc (38) is collected on a plurality of rotating magnetic disks (36) and as the disks rotate, a scraper (37) mechanically removes the magnetic floc (38) from the magnetic disks (36) and the magnetic floc (38) is discharged. Clear water (39) flows from the center of the magnetic disks (36) and is discharged (39).
[0144] FIG. 4 shows another embodiment of a MHRC that uses gravity to separate the magnetic floc. Wastewater (1) that has been pretreated in-line to adsorb and biologically remove DC and can contain MHC, WTR, MLSS, organic TSS, and probiotics are combined in-line with flocculating polymer (41) and magnetite (42) to form magnetic floc. The magnetic floc flows into a MHRC tank (40) where the magnetic floc settles by gravity and the settled magnetic floc is moved by a motor (43) powered scraper (44) to the center of the MHRC tank (40) and discharged (47). A baffle (45) causes the magnetic floc to settle to the bottom of the MHRC (40) tank and clarified water is discharged (46). Some water flows out the bottom of the tank in the form of a slurry but its flow rate is limited because it is transferred with a pump that limits the flow.
[0145] FIG. 5 shows the process for reusing WTR that contains TSS and spent coagulants that usually contain iron or aluminum to manufacture bricks. Water (50) is combined with an iron or aluminum coagulant (52) that neutralizes the negative charge of particles contained in the water (50) that then flows into a Clarifier (or MHRC) that discharges clarified water (53) and WTR (54). The WTR (54) flows into a Wastewater Conveyance System (55) where it combines with MHC (63), MLSS (64) produced by AST, and probiotics (65) grown using “process liquids” from HTC, separately or in combination. This combination of solids in the Wastewater Conveyance System (55) then flows to a MHRC (56) where the magnetic floc (62) produced as discussed above goes into Brick Production (59) and can undergo additional treatment to produce specialty adsorbents and catalysts (66). Clay (58) is added and bricks (60) are produced. In this case, the WTR replaces some of the water needed in brick-making, reduces clay consumption, provides carbon fuel, and supplies metal additives to enhance the quality of bricks.
[0146] FIG. 6 shows a further embodiment of a water treatment system according to the invention that combines technology with biology. Wastewater (70) flows through a Wastewater Conveyance System (71) where it comes into contact with probiotics (87) and magnetite (80) and then is contacted with flocculating polymer (72) to produce a magnetic floc that flows into a MHRC (73). Clarified water (74) exits MHRC (73) and magnetic floc (75) flows to a HDC (76) for the purpose of disinfecting pathogens contained in the magnetic floc, lysing organic cells to promote the growth of probiotics, breaking polymer floc bonds, and reducing the particle size of magnetite to improve its function as an adsorbent, all as described above. Another feature of this process is that organic wastes (77) such as food waste, grease trap waste, MLSS, animal waste, and septage can be processed in the HDC (76) to convert these wastes into solid organic fertilizer (83) and the filtrate (84) that contains valuable nutrients is used to grow probiotics. The magnetic floc (78) that has been processed by HDC (76) flows to a Magnetic Separator (79) that is composed of permanent magnets designed to recover magnetite (80) that is reused in the Wastewater Conveyance System (71). Prior to reuse of the magnetite (80), acid (88) is added to give a positive charge to the surface of the magnetite so it is effective in attracting the negatively-charged particles contained in sewage. Non-magnetic solids (81) from the Magnetic Separator (79) flow to a Reed Bed (82) that dewaters the solids (81) using solar energy and gravity. The dewatered solids (83) are useful as an organic fertilizer and the filtrate (84) provides nutrients to grow probiotics in a Probiotic Production (85) system. Produced probiotics are useful to irrigate (86) crops and useful to treat wastewater (87) in the Wastewater Conveyance System (71).
[0147] FIG. 7a shows a state of the art WWTP employing AST. Wastewater (90) flows into a primary clarifier (91) and solid waste (not shown for simplicity) is either discharged as WAS (96) or used in an anaerobic digester (not shown) to produce methane for electricity generation. Clarified water from the Primary Clarifier (91) is then biologically treated in an Aerobic Biological Treatment System (92) where bacteria convert DC into biosolids called Mixed Liquor Suspended Solids (MLSS). MLSS then flows to a Secondary Clarifier (93) where solids are separated and used as Returned Activated Solids (RAS) (95) to enhance the biological treatment process or Waste Activated Solids (WAS) (96) that is disposed. Clarified water from the Secondary Clarifier (93) is then disinfected by UV (94) or other disinfection method and discharged (100). Primary and secondary solids are dewatered (97) with the filtrate (99) returned to the head of the AST for additional treatment and the Biosolids (98) are normally disposed of.
[0148] FIG. 7b shows for comparison purposes an AST replacement system according to the invention, which reduces: (1) capital and operating costs (2) sludge production, (3) greenhouse gas emissions, (4) physical footprint, and (5) operating complexity and is especially suitable for applications in developing countries. Wastewater (101) flows through a conveyance system (107) and into a MHRC (102) where clarified water flows to UV (104) for disinfection and separated solids flow to a HDC (103) where they are disinfected and lysed. Flow from the HDC (103) goes to a Probiotic Production system (105) that grows probiotics according to this invention. Probiotics and magnetite are pumped upstream into the Influent Conveyance System (107) and probiotics only are pumped into the effluent line (106).
[0149] FIG. 8 shows wastewater (121) flowing through a water conveyance system (122), such as a lake, river, impoundment structure or the like, into which is injected a mixture of microorganisms (123) that treat the wastewater inside the water conveyance system (122) to consume undesirable organics. As indicated above, these microorganisms may include facultative bacilli and phages. The treated wastewater then flows through a flow control device (129) that controls the flow rate and the level of wastewater in the water conveyance system (122) to give microorganisms time to work. Biologically treated wastewater then flows through a screen device (130) that removes large solids and floatables. The screened wastewater then flows into a high-rate clarification device (132) where polymer (131) is added to flocculate fine suspended solids for removal. Flocculants may be employed together with magnetite to remove the flocculated solids, e.g., as described in applicant's co-pending application Ser. No. 14/612,635, filed Feb. 3, 2015, and incorporated herein by this reference. The clarified wastewater then flows through a disinfection device (134) and then through a conveyance system (135) and into a river (136). Solids removed by the high-rate clarification device flow (132) and as an alternative biosolids (125) from a WWI? (126) flow to a microorganism grow system (124). Also shown in this FIG. 8 are biocarriers (127) attached to the inside surface of the conveyance system (122) to increase the surface area for the growth of biofilm.
[0150] FIG. 9, comprising FIGS. 9(a) and (b), shows a flow control device that can be adjusted to change the water level in the conveyance system. The main purpose of the flow control device is to back up wastewater into the conveyance system to allow for additional time for biological treatment and to control and level out the flow of wastewater for subsequent treatment. The preferred flow control device is a V notch weir composed of two parts. One part (140) is a stationary weir and the other part is a movable weir (141) sealed to the stationary weir to prevent most water leakages. The flow control device has basically two positions. One position (FIG. 9(a)) determines a low-level pool height (142) that is employed during dry weather and another position (FIG. 9(b)) determines a high-level pool height (143) that is employed during wet weather events. This allows the residence time of water in the conveyance system to be controlled to be substantially constant despite varying flow rates in dry and stormy weather. A mechanical device (144) powers the movable weir (141).
[0151] FIG. 10 shows biologically treated wastewater (160) flowing through a conveyance system (161) and into a conveyance system extension (162) that has been positioned within or alongside a riverbed and where biological treatment is taking place. The biologically treated wastewater within the conveyance system extension (162) is then screened (163) to remove floatables, then clarified (164) to remove suspended solids, and then disinfected (165) to kill pathogens before the treated water is discharged (166) into a riverbed (167).
[0152] FIG. 11 shows a biological grow system (172) that receives organic wastes (171) from a WWTP (170) to produce select microorganisms that are either returned (173) to the WWTP (170) for use and/or piped (176) through a pipeline inserted inside the conveyance system (177) for inline bioaugmentation and/or piped (174) to the effluent of the WWTP (175).
[0153] While a preferred embodiment of the invention has been disclosed, the invention is not to be limited thereto.
