Abstract
The present Invention relates to a new and novel process for treatment of wastewater that combines treatment methods that use Ballast Material (BM), Hydrothermal Carbonization (HTC), Hydrodynamic Cavitation (HDC), Probiotics (PB), acid, and Bio-Adsorbents (BA) to replace biological treatment of wastewater, specifically Activated Sludge Technology (AST).
Claims
1. A method for treatment of wastewater, comprising the steps of: admitting the stream of wastewater to a primary clarifier; allowing relatively course waste suspended solids to settle out by gravity; removing the suspended organic waste solids from the primary clarifier and turning them into a carbon adsorbent that is used to remove dissolved pollutants from the water in an adsorber; admitting the clarified water from the primary clarifier to an adsorber that contains the carbon adsorbent; admitting the treated water from the adsorber to a secondary clarifier that has been modified by the addition of ballast material and flocculating polymer, such that a sludge comprising the ballast material, floc, and relatively fine particles settles to the bottom of the secondary clarifier; removing the clarified wastewater from the secondary clarifier, and disinfecting it; removing the sludge from the primary and secondary clarifiers; and processing the sludge to separate the ballast material from the floc and fine particles and to produce carbon adsorbents.
2. The method of claim 1, wherein said step of adding ballast material and flocculating polymer to said stream of waste water is performed in-line before the secondary clarifier.
3. The method of claim 2, wherein static and in-line mixers are employed to improve the in-line flocculation process to form ballast material floc.
4. The method of claim 1, wherein the step of processing the sludge to separate the ballast material from the floc and fine particles shears the ballast material floc to separate ballast material from the flocculant and from other lighter weight solids so that cleaned ballast material can be reused in the in-line flocculation process.
5. The method of claim 4, wherein a sludge processing unit is employed to take organic solids from the ballast material recovery system and converts them into probiotics, ballasted hydrochar, or bio-absorbents.
6. The method of claim 5, wherein the sludge processing unit contains (1) acid addition prior to treatment by hydrodynamic cavitation to lyse cells to release heavy metals and phosphorus for later removal and to reduce the particle size to enhance hydrothermal carbonization performance by reducing reaction residence time and increasing surface area of ballasted hydrochar, (2) precipitation and recovery of heavy metals and phosphorus through chemical precipitation in a two stage process, (3) treatment with hydrothermal carbonization to convert carbon contained in the sludge into ballasted hydrochar, (4) a probiotic production system to grow probiotics using either lysed liquids from hydrodynamic cavitation or “process liquids” from hydrothermal carbonization, and (5) a colonization system to grow probiotics on ballasted hydrochar to produce bio-absorbents.
7. The method of claim 6, wherein said probiotics are selected from the genus Bacillus including B. Subtilis, B. Subtilis var. amyloliquefaciens, B. Licheniformes, B. Indicus, B. Pumilus, B. Megaterium, B. Coagulans, B. Cereus, and B. Clausii and from the genus Pseudomonas.
8. The method of claim 6, comprising the further step of promoting the colonization of probiotics on ballasted hydrochar, which acts as a biocarrier and then adding this bio-absorbent to a wastewater conveyance system to convert the conveyance system into an in-line treatment system.
9. The method of claim 6, wherein hydrodynamic cavitation is used post hydrothermal carbonization to (1) reduce the particle size of ballasted hydrochar particles to increase their adsorbent capacity, (2) reduce dissolved pollutant adsorption time, and (3) provide additional surface area for the colonization of probiotics.
10. The method of claim 6, wherein dry organic wastes are added to solid wastes produced by the ballast material recovery system to achieve a combined dry solids level greater than approximately 10% for optimum hydrodynamic carbonization performance.
11. The method of claim 6, wherein the surface of ballasted hydrochar is modified to make it hydrophilic by the addition of chemical treatment to promote the colonization of probiotics and to improve the adsorbency of colonized ballasted hydrochar.
12. The method of claim 6, wherein the ratio of ballasted hydrochar, ballast material, and probiotics contained in bio-absorbents is controlled to select their buoyancy and the buoyancy of ballasted hydrochar is modified by an activation process that increases the amount of void spaces contained in the ballasted hydrochar.
13. The method of claim 11, wherein the surface of the ballasted hydrochar is modified by chemical treatment that permanently modifies the surface charge so that it is better suited for adsorbing target pollutants.
14. The method of claim 5, wherein an education system is used to entrain recovered ballast material and fresh ballast material into a flowing stream of water without the use of pumps to transport ballast material floc from the second clarifier to the sludge processing unit.
15. The method of claim 1, wherein the clarifiers are configured as vortex separators.
16. The method of claim 1, wherein ballast floc removed from the primary and secondary clarifiers is transported using an inductor that transports the ballast floc to a ballast floc cleaning system.
17. The method of claim 1, wherein the ballast cleaning system contains two stages, the first stage separating water from floc by gravity, followed by a shear device that breaks the polymer bond between ballast from waste solids, followed by a second stage that separates ballast from waste solids by gravity.
18. The method of claim 1, wherein the ballast material has a specific gravity greater than 2.0, particle size between 40 and 200 microns, and includes but is not limited to sand, fly ash, magnetite, and zero valent iron.
19. The method of claim 1, wherein the flocculating polymer is either anionic, nonionic, or cationic, and preferably is a polyacrylamide flocculating polymer.
20. The method of claim 14, wherein the surface charge of BM and the adsorbent properties MBM can be modified and enhanced by methods such as but not limited to chemical, thermal, or crosslinked coatings such a polydimethylsiloxane.
21. The method of claim 5, wherein the probiotics produced from organic wastes recovered from the primary and secondary clarifiers is used to reduce odor, corrosion and the buildup of FOG in the conveyance system and is also added to improve the biological condition of the receiving waterway.
22. The method of claim 20, wherein the density of MBM can be increased or reduced to make it either float, be neutrally buoyant, or sink if discharged into a receiving waterway.
23. The method of claim 1, wherein BM and flocculant are also added prior to the first clarifier to assist removing fine solids.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0131] Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
[0132] FIG. 1 shows the State of the Art for AST.
[0133] FIG. 2a shows an overview of this invention in a primary treatment mode that uses BM to clarify wastewater and uses removed organic wastes to grow PB that are used either in-line to improve conveyance system operation or in the effluent to increase food production or to improve the biological health of a waterway.
[0134] FIG. 2b shows an overview of this invention in a secondary treatment mode that first uses BM in a primary clarifier, then an adsorber to remove dissolved pollutants, and finally a secondary clarifier to remove remaining solids. Solids removed by the primary and secondary clarifiers are treated in a Sludge Processing System to grow PB and produce BHC.
[0135] FIG. 3 shows the details of a Sludge Processing System that uses HDC and HTC to produce BHC and PB with heavy metals and phosphorus removed and recovered.
[0136] FIG. 4 shows the details of a PB Production System that uses treated liquids from HDC and “process liquids” from HTC to grow PB.
[0137] FIG. 5 shows the details of a BM Recovery System retrofit to an existing gravity clarifier or HSS to increase its treatment capacity and to clean and recover BM in a two-stage treatment system.
[0138] FIG. 6 shows the details of an Eductor System to entrain clarified transfer water and
[0139] BM into a flowing stream of wastewater.
[0140] FIG. 7 shows the details of a three-stage treatment system designed for treating sewage in developing countries.
[0141] FIG. 8 shows the details of a shear tube that mechanically separates BM from waste solids.
DETAILED DESCRIPTION OF THE INVENTION
[0142] While this invention is susceptible of embodiment 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 this invention, and is not intended to limit this 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.
[0143] FIG. 1 shows the State of the Art for AST. Wastewater flows through a conveyance system (1) into a Primary Clarifier (2) that separates solids from water by gravity into a sludge slurry that flows to Dewatering (10). Clarified water from the Primary Clarifier (2) flows into Aerobic Biological Treatment (3) that uses bacteria and oxygen (4) to treat dissolved organic wastes. Treated water that contains MLSS flows from Aerobic Biological Treatment (3) into a Secondary Clarifier (5) that separates MLSS from clarified water. MLSS either flows (9) back to Aerobic Biological Treatment (3) as Returned Activated Sludge (RAS) or as Waste Activated Sludge (WAS) that flows (8) to Dewatering (10). In a retrofit embodiment of this invention, the effective performance of either or both clarifiers may be improved by employment of ballast material and flocculant, to improve settling of pollutants in the water stream.
[0144] FIG. 2a shows an overview of this invention operating in a primary treatment mode. Wastewater flowing through a conveyance system (1) is combined with BM and flocculating polymer (42) before it enters into a Primary Clarifier/HSS (13) that removes TSS with the use of BM and flocculating polymer. The Primary Clarifier/HSS (13) separates BM, which after cleaning in the BM Cleaning System (75), is returned (40) to the wastewater conveyance system (1) to be reused to flocculate solids in-line before the Primary Clarifier/HSS (13). Separated solids from the BM Cleaning System (75) flows to Probiotic Production (15). Probiotic Production (15) disinfects solids and grows probiotics that are combined with treated effluent (16) after it has been disinfected (14).
[0145] FIG. 2b shows an overview of this invention operating in a secondary treatment mode that, rather than using biological treatment in an aeration basin as in AST, uses BHC to adsorb dissolved pollutants in an adsorber. Wastewater containing TSS, dissolved contaminants, BHC, and PB flows through a conveyance system (1) into a Primary Clarifier/HSS (17), which is either a gravity clarifier or a HSS that has been modified by the addition of BHC, MBM, or BM and flocculating polymer to increase its clarification capacity. Clarified water flows from the Primary Clarifier/HSS (17) into an Absorber (18) where it is combined with BHC and PB (27) received from Sludge Processing (23) to adsorb dissolved contaminants contained in the wastewater. Waste solids that are removed from the Primary Clarifier/HSS (17) flow as a slurry (22) to Sludge Processing (23) where organic solids are converted into BHC and PB (25). These flow separately or combined either upstream (28) into the conveyance system (1) to reduce odor, corrosion, and the buildup of FOG, or into the Adsorber (18) a device that contacts an adsorbent with an adsorbate with the purpose to remove dissolved pollutants, or into the Secondary Clarifier/HSS (19) or into the effluent (21) to improve the biological health of the receiving waterway or to irrigate for food production. Treated water from the Adsorber (18) containing BHC and PB then flows into the Secondary Clarifier/HSS (19) that removes suspended solids that flow (22) into Sludge Processing (23), and clarified water from the Secondary Clarifier/HSS (19) is Disinfected (20) before discharge (21). Supplemental sources of Organic Wastes (24) may be added to Sludge Processing (23) to increase the production of PB and BHC.
[0146] FIG. 3 shows the details of the Sludge Processing System that uses HDC (32) and HTC (34) to produce BHC and PB with heavy metals removed and phosphorus reduced. A slurry of carbon solids (30) flowing from Primary and Secondary Clarifiers/HSS combine with acid (31) to achieve a pH of less than 3.0 that is used to weaken cell membranes of toxic bacteria so they are more easily lysed in HDC, to dissolve heavy metals and phosphorus in biosolids (30) so they can be separated, and to pretreat biosolids to increase the porosity of BHC. The carbon solids (30) then flow into HDC (32) that uses collapsing microbubbles to break (lyse) organic cell membranes, releasing cell liquids containing heavy metals and phosphorus and reducing particle size to improve the treatment efficiency of HTC and increase the adsorption capacity of BHC. Liquids separated from Thickener (33) that separates solids from liquids by gravity or other mechanical means are treated in-line with a metal precipitant (45) and heavy metals (47) are removed with MHRC (46). Treated liquids from Separator (46) are then treated in-line with a phosphate precipitant (48) and phosphorus (50) is removed with Separator (49). Treated liquids that retain dissolved nutrients (52) then flow to Probiotic (PB) Production (39). Separated lysed solids from Thickener (33) then flow into HTC (34) where heat and pressure convert waste into BHC and “process liquids”. In addition, solid organic wastes such as food waste, agri-waste, and grease trap wastes (35) are also processed in HTC (34) and help to increase the solids concentration to a degree necessary for efficient HTC (34) operation (>10 wt. % solids). The pH of flow from HTC (34) is raised with caustic (36) to a range of 6-9 necessary to promote the growth of PB and then flows into a second Thickener (37) that splits the flow into BHC (51) that flows into Probiotic/HC Colonization (41) and “process liquids” (38) that flows to Probiotic (PB) Production (39). PB from Probiotic (PB) Production (39) flow into Probiotic/HC Colonization (41) to colonize with BHC (51) to form new BA. BA then can either flow (43) back into the conveyance system or flow (44) into an adsorber.
[0147] More specifically, HTC is a carbonization process that uses water, moderate temperature, and moderate pressure to increase the carbon levels in wet organic wastes. As shown in FIG. 3 (Sludge Processing System) wet organic solids are wastes from the primary and secondary MHRCs, are used to produce three carbon based products. The most prevalent material is a solid called HC, an effective carbon adsorbent, that is used in this invention to adsorb dissolved pollutants in an adsorber. Also produced (not shown in FIG. 3 for simplicity) are gases that contain hydrocarbons that can be either recycled back into the HTC process or used as a chemical feedstock. The final product is a “process liquid” that contains dissolved organics. It is this process liquid that is used to grow PB in this invention as also shown in FIG. 3.
[0148] FIG. 4 shows the details of a Probiotic Production System that uses nutrients from dissolved organics and organic waste solids to grow PB. First, a slurry of organic wastes (53) flows into Macerator (55) that reduces the particle size of organic wastes (53) to produce a homogeneous feed slurry that flows to HDC (56) that further reduces organic waste particle size, disinfects pathogens contained in the macerated slurry to reduce competition with PB, and lyses cell membranes to release liquid nutrients beneficial for the growth of PB. The treated slurry from HDC (56) then flows into a Recirculation Tank (57) and is then pumped (58) back to HDC (56) for further processing. Treated slurry that has been lysed and disinfected by HDC then flows to a Thickener (59) that separates solids (54) that are processed into BHC or solid fertilizer and separated liquids (60) flow to Probiotic Grow Tank (62) along with “process liquids” from HTC (61). PB either flows (64) to the conveyance system (1) to reduce operating problems or is colonized on BHC or flows (63) into the effluent to improve the biological health of the receiving or is used to improve biological treatment at a WWTP.
[0149] FIG. 5 shows the details of a system that recovers BM from an existing gravity clarifier or HSS that has been retrofitted to increase its treatment capacity by the addition of BM and flocculating polymer. BM floc settles in the gravity clarifier or HSS and discharges as a slurry (66) into the BM recovery system as shown in FIG. 5. The first stage of the BM recovery system is a gravity thickener (67) that receives BM floc (66) from a gravity clarifier or HSS and separates BM floc from transfer water (68). Transfer water, separated by the first gravity thickener (67), flows (68) back through an eductor (65) into the conveyance system (1). Settled floc (69) from the first gravity thickener (67) flows into a shear tube (70) that separates BM from carbon solids using mechanical shear force. The sheared slurry flows into a second gravity thickener (71), which separates solid carbon wastes (72) that is disposed of or reused to produce carbon adsorbents from cleaned BM (73). Cleaned BM (73) combines with new BM (74), and flows through an eductor (76) back into the conveyance system (1) where it combines with flocculating polymer (77). With the aid of a static mixer (78) and/or a mechanical mixer (79), BM floc (80) is formed, which flows into a gravity clarifier or HSS to enhance its performance.
[0150] FIG. 6 shows the details of a first Eductor System (42) that entrains transfer water (81) through an Eductor (82) and into a conveyance system (1) in which a stream of wastewater (86) flows. A second Eductor System (83) entrains clean and fresh BM (84) into the same conveyance system (1) flowing a stream of wastewater (86). Both Eductors use venturi forces to draw transfer water (81) and BM (84) into the conveyance system (1) that contains a flowing stream of wastewater (86). Downstream, flocculating polymer (87) is added to form a BM floc that then flows into a gravity clarifier or HSS.
[0151] FIG. 7 shows the details of a process to treat sewage as a replacement for biological treatment best suited for developing countries. Raw sewage flows through a conveyance system (1) and into a Primary HSS (101) that separates floatables, grit, filterable solids, and grease that are discharged as waste (102). Treated sewage from the Primary HSS (101) flows into a Secondary HSS (105). Prior to entering the Secondary HSS (105), lime (103) is added for pH control and to act as a coagulant if necessary, recovered BM (111) is added as is flocculating polymer (104) to attach TSS to BM, and to form BM floc that then flows into the Secondary HSS (105). The BM floc enters the Secondary HSS (105) tangentially, causing the water and BM floc to move in a circular direction that forces the BM floc to concentrate in the center of the Secondary HSS (105) and settle by gravity to the bottom where it flows into a BM Recovery system (106). Mechanical forces in the BM Recovery system (106) cause BM (111) to separate from the waste sludge (110). BM (111) flows back into the Secondary HSS (105) for reuse, while waste sludge (110) is combined with lime (109) for disinfection and flows into Sludge Treatment (112) and after treatment exits (113) for reuse in agriculture. In Sludge Treatment (112), HDC is used to aid in the disinfection of the waste sludge and to micronize the lime to reduce its usage and increase its effectiveness as a disinfectant. Clarified wastewater exits the Secondary HSS (105) and flows to Disinfection (107) and is discharged (108).
[0152] FIG. 8 shows the details of a device to clean BM or MBM so they can be recovered for reuse. BM floc (88) flows into a shear tube (89) with the purpose of disrupting the bond between BM and suspended solids caused by the presence of flocculating polymer. Inside the shear tube (89) is contained a plurality of shear blades (90) attached to a rotating shaft (91) that is moving at a fast pace, e.g., 1750 rpm. The sheared BM floc (92) then exits the shear tube (89) and flows into a gravity thickener that separates BM from waste solids by gravity.
