COMMERCIAL LAUNDRY WASTE WATER TREATMENT SYSTEM
20180347100 ยท 2018-12-06
Assignee
Inventors
- Russell H. Poy (New Orleans, LA)
- Kyle Anthony WOLFF (London, GB)
- Sharon Monica MAK (New Orleans, LA, US)
Cpc classification
C02F1/006
CHEMISTRY; METALLURGY
B01D65/02
PERFORMING OPERATIONS; TRANSPORTING
C02F11/008
CHEMISTRY; METALLURGY
B01D2317/06
PERFORMING OPERATIONS; TRANSPORTING
B01D69/081
PERFORMING OPERATIONS; TRANSPORTING
C02F1/001
CHEMISTRY; METALLURGY
C02F2201/008
CHEMISTRY; METALLURGY
C02F2103/002
CHEMISTRY; METALLURGY
C02F2301/08
CHEMISTRY; METALLURGY
B01D63/04
PERFORMING OPERATIONS; TRANSPORTING
D06F31/005
TEXTILES; PAPER
International classification
B01D63/04
PERFORMING OPERATIONS; TRANSPORTING
B01D65/02
PERFORMING OPERATIONS; TRANSPORTING
B01D69/12
PERFORMING OPERATIONS; TRANSPORTING
C02F1/68
CHEMISTRY; METALLURGY
Abstract
The present invention provides a method of treating a commercial or industrial laundry wastewater stream. The method and apparatus treats a commercial laundry waste stream from a commercial washing machine or machines wherein the waste includes total suspended solids, chemical oxygen demand, biological oxygen demand, turbidity, and bacteria. The waste stream is transmitted to a first treatment unit that has a membrane filter that filters particles of between about 6 and 40 nanometers. At the first treatment unit, the waste stream is separated into a permeate stream and a retentate component. The retentate component is transmitted to a second treatment unit that filters particles of between about 3 and 10 nanometers. The permeate stream is then transmitted to a permeate holding vessel after treatment in the second treatment unit. The retentate component is placed in a mixing vessel where it is mixed with a polymer to form a solid waste.
Claims
1. A method of treating a commercial laundry waste stream, comprising the steps of: a) discharging the commercial laundry waste stream from one or more commercial washing machines, wherein the waste stream includes one or more of suspended solids, dissolved solids, and CBOD (chemical biological oxygen demand); b) transmitting the waste stream to a first treatment unit that has a membrane filter that filters particles of between about 20 and 200 nanometers (nm); c) separating the waste stream of step b into a permeate stream and a retentate component, wherein the retentate component is smaller than the permeate stream; d) transmitting the retentate component of step c to a second treatment unit that filters particles of between about three and twenty (3-20) nanometers; e) transmitting the permeate stream of step c to a permeate holding vessel; and f) after step d mixing the retentate component in a mixing vessel with a polymer, or polymer blend to form a solid waste.
2. The method of claim 1 wherein in step d a second permeate flow stream discharges from the second treatment unit.
3. The method of claim 1 wherein in step d the retentate component is reduced to between about 0.1 and 0.5 liters per kilogram.
4. The method of claim 1 wherein the filtered permeate stream has a chemical biological oxygen demand (BOD) that is reduced by over seventy percent (70%) in steps a through f.
5. The method of claim 1 wherein the filtered permeate stream has a chemical biological oxygen demand (BOD) that is reduced by about ninety percent (90%) in steps a through f.
6. The method of claim 1 wherein the filtered permeate stream has total suspended solids (TSS) that was reduced by over seventy percent (70%) in steps a through f.
7. The method of claim 1 wherein the filtered permeate stream has total suspended solids (TSS) that was reduced by about ninety-six percent (96%) in steps a through f.
8. The method of claim 1 wherein the filtered permeate stream has turbidity that was reduced by over seventy percent (70%) in steps a through f.
9. The method of claim 1 wherein the filtered permeate stream has turbidity that was reduced by about ninety-eight percent (98%) in steps a through f.
10. The method of claim 1 wherein the filtered permeate stream has a non-detectable level of E-Coli after steps a through f.
11. The method of claim 1 wherein one of said treatment units includes a bundle of at least 200 hollow fiber ceramic membranes.
12. The method of claim 1, wherein the polymer, polymer blend can be composed of mixtures of superabsorbent polyacylate polymers with inorganic clays.
13. The method of claim 1, wherein the polymer, polymer blend can be bentonite clay.
14. The method of claim 12, wherein the superabsorbent polyacrylate - clay mixtures can contain about 30% to 80% superabsorbent polyacrylate.
15. The method of claim 1 wherein in step f the retentate component includes highly concentrated biological oxygen demand (B.O.D.) of between about 1938 and 13,900 mg/L, Chemical oxygen demand (COD) of between about 2,805 and 17,595, total dissolved solids (T.D.S.) of between about 3250-4550 mg/L and Total suspended solids (T.S.S.) of between about 450-3200 mg/L.
16. The method of claim 1, wherein the membrane filter can be include multiple pairs of risers, each said pair of risers including a first and second elbows.
17. A method of treating a commercial laundry waste stream, comprising the steps of: a) discharging the commercial laundry waste stream from a commercial washing machine, wherein the waste stream includes one or more of suspended solids, dissolved solids, and CBOD (chemical biological oxygen demand); b) transmitting the commercial laundry waste stream wherein the waste stream is treated with a filter to remove particles of between about twenty and two hundred nonometers; c) separating the waste stream of step b into a permeate stream and a retentate component; d) transmitting the retentate component of step c to a second treatment unit that removes particles of a second size that is between about three and twenty (3-20) nanometers; e) transmitting the permeate stream of step c to a permeate holding vessel; and f) after step d, solidifying the retentate component by combining the retentate component with a polymer.
18. The method of claim 17 wherein one of said treatment units includes a bundle of at least 200 hollow fiber ceramic membranes.
19. The method of claim 18 wherein each hollow fiber ceramic filter is tubular, having a central longitudinal bore.
20. The method of claim 17 wherein in step f the retentate component includes highly concentrated biological oxygen demand (B.O.D.) of between about 1938 and 13,900 mg/L, Chemical oxygen demand (COD) of between about 2,805 and 17,595, total dissolved solids (T.D.S.) of between about 3250-4550 mg/L and Total suspended solids (T.S.S.) of between about 450-3200 mg/L.
21. The method of claim 17 wherein the permeate stream of steps c and e is comprised of non-detectable levels of E-Coli and turbidity of less than one (1) nephelometric turbidity units (N.T.U.).
22. The method of claim 18 wherein there are multiple modules, each module having a bundle of hollow fiber ceramic membrane.
23. The method of claim 17 wherein both of said treatment units includes a bundle of at least 200 hollow fiber ceramic membranes.
24. The method of claim 18 wherein there are a plurality of said bundles.
25. The method of claim 24 wherein at least some of said bundles are vertically stacked one upon the other and wherein the waste stream flows from a lower of said bundles to an upper of said bundles.
26. The method of claim 17, wherein the polymer, polymer blend can be composed of mixtures of superabsorbent polyacylate polymers with inorganic clays.
27. The method of claim 17, wherein the polymer, polymer blend can be bentonite clay.
28. The method of claim 26, wherein the superabsorbent polyacrylate - clay mixtures can contain about 30% to 80% superabsorbent polyacrylate.
29. The method of claim 18, wherein the ceramic membranes can include multiple pairs of risers, each said pair of risers connected with one or more elbow fittings.
30. (canceled)
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0035] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0036]
[0037]
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[0039]
[0040]
[0041]
[0042]
[0043]
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[0045]
DETAILED DESCRIPTION OF THE INVENTION
[0046]
[0047] Preferably, two (2) flow lines receive discharge from treatment unit 15. These flow lines include retentate flow line 16 and permeate flow line 17. Line 16 preferably transmits retentate to retentate tank 18. Flow line 19 preferably transmits retentate from tank 18 to retentate treatment module 20. Treatment module 20 preferably uses a membrane (e.g., ceramic membrane) to filter particles between about three (3) and twenty (20) nanometers (nm), removing those particles from the material flowing to unit 20 via line 19. The discharge from retentate treatment module 20 preferably includes flow line 21 and flow line 24. Lines 21 and 24 include permeate flow line 21 and retentate flow line 24. Flow line 21 can combine with permeate flow line 17 at tee fitting 22. Flow lines 17, 21 discharge into permeate tank 23.
[0048] Flow line 24 preferably discharges retentate to mixing unit 25. In mixing unit 25, retentate from flow line 24 can be treated with a polymer that will combine with the retentate to generate a solid waste 27. The polymer can be a super-absorbent sodium polyacrylate (C.sub.3H.sub.3NaO.sub.2)n or potassium polyacrylate [CH.sub.2CH(CO.sub.2K)]n polymer. A polymer blend applied can compose of more than 99 percent polyacrylate polymers or a blend with chemically inert and natural occurring inorganic additives such as clay (smectite clay minerals) and zeolites. Upon contact with water, the sodium ions within the polymer disassociates from the carboxylate ions to create higher osmotic pressure within the gel to absorb the free water. The hydrophilic polymer or polymer blend has high absorbency rate of more than 100 of its weight in aqueous fluids including the retentate component. The polymer blend with inorganic clay or zeolites can provide adsorption of organic matters attributed by the on-exchange properties and large surface area of the inorganic clay minerals. Free liquid containing high suspended solids, dissolved solids, organic matter, oils and greases can be immobilized by way of absorption and/or adsorption to create solid wastes. The polymer or polymer blend prevents release of liquids when compressed, hence, converting liquid waste to a stable solidified form for landfill disposal. Such polymers are commercially available (e.g., from Metaflo Technologies of Toronto, Canada and Dover, Del. (www.metaflotech.com/ca)). Arrow 26 represents a discharge of solids or solid waste 27 from mixing unit 25. Solids or solid waste 27 can be transported to a suitable disposal facility 28, as indicated by arrow 29.
[0049] The polymer or polymer blend can be commercially available in fine powder form. Such a polymer can be of a white/beige color; bulk density ranging from about 0.4 to 1.11 grams per cubic centimeter and particle size less than about 400 microns. The polymer or polymer blend application rate can be in the range of about 1 to 10 percent (wt/wt) based on a weight percentage, and preferably in the range of about 1 to 4 percent (wt/wt) being about 1 to 4 kg per cubic meter retentate. The application rate can vary according to total dissolved solids content of retentate and polymer blends to generate stable solids. The polymer or polymer blend can be added via a controlled batch dosing system into a mixing vessel to increase dispersion and reduce contact time. Alternatively, the polymer or polymer blend dosing and mixing with retentate can also be undertaken via continuous retentate flow using a commercially available dosing and mixing apparatus such as Metaflo LMS supplied by Metaflo Technologies, Inc. (e.g., see U.S. Pat. No. 7,901,571). The solid waste formed would be disposed according to local landfill and regulatory requirements.
[0050] Using a method and apparatus of the present invention, test results on a waste stream that was treated show reductions in several parameters. The method and apparatus of the present invention reduced chemical biological oxygen demand (CBOD) by about ninety percent (90%) when treating a commercial laundry wastewater stream. The method and apparatus of the present invention reduced total suspended solids (TSS) by about ninety-six percent (96%) when treating a commercial laundry wastewater stream. Turbidity for the treated commercial laundry wastewater stream was reduced about ninety-eight percent (98%). Treatment of a commercial laundry wastewater stream using the method and apparatus of the present invention filtered E-Coli bacterial to non-detectable levels.
[0051] The following are examples of clay-polymer composite mixtures of the present invention and effluent characteristics.
Inorganic Clay Additive Used in Polymer Blend:
[0052] a. Polymer blends can be composed of mixtures of superabsorbent polyacylate polymers with inorganic clays such as bentonite clay (also known as montmorillonite clay) classified under the smectite group.
[0053] b. Bentonite clay (such as sodium bentonite) has excellent liquid sorption capacity and ion-exchange properties due to the exchangeable interlayers of cation (sodium in the case of sodium bentonite). These interlayers bind the aqueous retentate, resulting in swelling of the clay structure.
[0054] c. The polymer blend can be formulated to the retentate water quality characteristics such as total dissolved solids or conductivity.
[0055] d. Example superabsorbent polyacrylateclay mixtures can contain about 30% to 80% superabsorbent polyacrylate.
[0056] e. Such polymer blends may reduce application cost.
Retentate Characteristics:
[0057] Retentate is generated from Treatment Module No. 2 (20, 145) by filtering the reject produced Treatment Module No. 1 (15, 144).
[0058] Example of raw wastewater and Treatment Module No. 2 (20, 145) Retentate characteristics:
TABLE-US-00002 Raw Retentate Wastewater From treatment from washers module no. 2 Oils and greases, mg/L 50-300 185-590 (O&G) Total dissolved solids, mg/L 2500-3500 3250-4550 (TDS) Total suspended solids, mg/L 170-1200 450-3200 (TSS) Biological oxygen demand 600-4300 1938-13,900 (BOD) mg/L Chemical oxygen demand 1,100-6,900 2,805-17,595 (COD) mg/L
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[0060] The filtration device/skid 40, 70 in
[0061] In
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[0064] There can be between about two hundred and fifteen hundred (200-1500) hollow fiber ceramic membranes 71 in each module 15, 20, 144, 145. These membranes 71 are preferably bundled together to provide an overall cylindrically shaped bundle 74 of membranes 71 that are held in the cylindrically shaped bundle shape with end bands or end caps 84, 85. Flow of waste 112 preferably enters each module (and thus each hollow fiber ceramic membrane 71) at one end 84, discharging at the other end 85. In
[0065] Channels 75 of membranes 71 are preferably open ended so that wastewater 112 enters channel 75 at a first end 84 then exits channel 75 at a second end 85. Membrane 71 can have a generally cylindrically shaped wall 77 surrounding channel 75. Wall 77 has inner surface 86 with a separating layer of porous polymeric material or porous ceramic material.
[0066]
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[0068] Feed tank or vessel 114 receives flow from sump 115 and screen 113 via flow lines 116, 117. Feed tank 114 transmits the wastewater stream 112 to the various pump, valve and treatment module components that can be for example skid mounted on skid or base or frame 62 (see
[0069] The method of the present invention intermittently alternates fluid to a left hand side membrane loop conduit 139 then to the right hand side membrane loop conduit 140 via a 180 degree elbow. In between the left hand conduit filtration and the right hand conduit filtration is preferably a backwash cycle (see
[0070] In one embodiment, the method includes heating the wastewater stream or effluent held in a feed tank 114 by way of a valve 121 (e.g., actuated control valve) and heater or steam injector line 120. Feed tank 114 can have a level control and overflow line 119. Steam or heater 120 may be operable to heat the wastewater or effluent in tank 114 to about 40 degrees centigrade or more. The heater 120 may be operable to heat the effluent to about 50 degrees centigrade or more. The heater 120 may be operable to heat the effluent to within a temperature range of about 50 to 80 degrees centigrade. The heater 120 may be operable to heat the effluent to about 60 degrees centigrade or more.
[0071] Once effluent 112 is preferably at a temperature of between about 50 and 80 degrees centigrade, the feed pump 122 is preferably enabled to a set point of between about 1-10 bar. Pump 122 receives flow from feed tank 114 via line 123 with valve 124. Pump 122 pumps to line 126 which is preferably an inlet conduit. From pump 122, flow goes to pump 125 (circulation pump) preferably via valve 127, and through valve 135 or 136 to the filtration modules 144 or 145. There are two (left and right) conduits 139, 140 each with multiple modules 144 or 145. Each module 144 or 145 is preferably contained in a stainless steel conduit or pipe 139 or 140 that enables filtered water to be collected after filtration through each hollow fiber ceramic membrane 71. The stainless steel conduit or pipe 139, 140 also contains fluid used for backwash in an out to in flow path.
[0072] There are preferably eighteen (18) modules including nine (9) left side modules 144 and nine (9) right side modules 145. The membrane modules 44, 45 can be individual or stacked forming a vertical or horizontal column. A circulation loop conduit (lines 137, 139, 140, 138) feeds the hollow fiber ceramic membrane modules 144, 145. During this method, crossflow occurs at each hollow fiber membrane 71 in the module 144 or 145, separating contaminated effluent that is preferably channeled to both the retentate conduit 141 and clean fluid conduits 150, 151, 152 known as permeate to the permeate clean tank 157.
[0073] Pump 122 supplies the wastewater 112 to circulation pump 125 via line 126 and valve 127. Tee fitting 132 connects line 126 and 133. Pump 125 discharges into line 131 and tee fitting 134 which provides selective transmission of fluid to either line 137 or 138 depending upon the open or closed state of valves 135, 136.
[0074] A circulation is preferably enabled during filtration by transmitting the wastewater 112 in a first direction through lines 139, 140 and modules 144, 145 and back to circulation pump 125 via flow line 133.
[0075] Retentate line 141 enables transmission of retentate to feed tank 114 via valves 142, 143. Part of the retentate stream of line 141 can be discarded to drain or sewer 149 via drain line 147 and valve 148. Permeate flow lines 150, 151, 152 transmit cleaned fluid from modules 144, 145 to permeate tank 157. Line 152 has valve 188. Permeate lines 150, 151 connect to line 152 at tee fittings 154, 155. Permeate tank 157 can be used for backwashing. Line 166 is preferably a backwash flow line having valve 156. Line 166 joins line 123 at tee fitting 169. Line 161 enables pH adjustment of permeate water in tank 157. pH adjustment device 159 enables a desired pH adjustment via line 161 and pump 160. Clean water can be transmitted to commercial laundry 11 via flow line 163, pump 164 and discharge line 165. Water can optionally be discharged from feed tank 114 via flow line 198 and valve 199 to sewer 149.
[0076]
[0077] The present invention can optionally use cleaning in place. Cleaning in place can include the external injection from clean in place dosing tank 128 and pump 129 and via line 130 into the commercial or industrial laundry effluent treatment device of an alkali or acidic solution into the feed tank 114, mixed with clean water being city or permeate water. Clean in place is operable to preserve, maintain or restore the clean fluid permeation flow through the ceramic hollow fiber wall 77, being either individual or multiple hollow fiber membranes 71, which includes nominal 220 to 1500 individual ceramic hollow fibers 71 made of a substrate such as an aluminium oxide (Al.sub.2O.sub.3) substrate material. Selective pore sizes of the aluminium oxide substrate material (Al.sub.2O.sub.3) can be about 50 to 1400 nanometers, also but not limited to selective pore sizes of the aluminium oxide substrate material (Al.sub.2O.sub.3) being nominal 50 to 1400 nanometers, including nominal 1 to 100 nanometers ceramic or porous polymeric coating or multiple separate porous ceramic or polymeric coatings, acting as a separation layer attached to the membrane fiber wall at inner surface 86. In one embodiment, clean in place device 128 transmits a selected cleaning chemical from the dosing device 128 and pump 129 to tank 114. Valves 124, 127, 135, 136, 142, 143, 156, 167, 168 and 188 are opened. Valve 200 is opened to drain all fluid via line 201 to sewer 149. Line 198 and valve 199 can also be used to drain all fluid. Clean in place cycle can have a duration of about 60-1200 seconds. In one embodiment, valves 124, 127, 135, 142, 143, 153 and 168 are preferably open. Flow to valve 153 is via line 158.
[0078] The following is a list of parts and materials suitable for use in the present invention:
TABLE-US-00003 PARTS LIST: PART NUMBER DESCRIPTION 10 laundry waste water treatment system 11 tunnel washer/commercial washer 12 feed tank 13 flow line 14 flow line 15 treatment module/unit 16 flow line 17 flow line 18 retentate tank 19 flow line 20 retentate treatment module/unit 21 flow line 22 tee fitting 23 permeate tank 24 flow line 25 dosing/mixing unit/system 26 arrow 27 solid waste 28 disposal facility 29 arrow 40 filtration device/skid 41 feed pipe 42 recirculation pump 43 butterfly valve 44 butterfly valve 45 butterfly valve 46 butterfly valve 47 butterfly valve 48 butterfly valve 49 butterfly valve 50 butterfly valve 51 butterfly valve 52 butterfly valve 53 butterfly valve 54 butterfly valve 55 butterfly valve 56 pressure transmitter 57 flow meter 58 flow meter 59 turbidity meter 60 flow meter 61 pressure transmitter 62 globe valve 63 pressure transmitter 64 control panel 65 future filter expansion 66 stacked filters/modules/spool piece 67 stacked filters/modules/spool piece 70 filtration device/skid 71 fiber/member/membrane/filter/hollow fiber ceramic membrane 72 elbow fitting 73 elbow fitting 74 bundle 75 channel/inside channel 76 outside surface 77 wall 78 arrow 79 arrow 80 arrow 81 arrow 82 arrow 83 arrow 84 end cap 85 end cap 86 inner surface 110 wastewater treatment apparatus 112 commercial/industrial laundry effluent/wastewater 113 pretreatment screen/filter/vibrating screen 114 feed tank/vessel 115 sump/effluent sump 116 flow line 117 flow line 118 pump 119 overflow line 120 steam/steam inlet/steam flow line/heater 121 valve 122 feed pump 123 flow line 124 valve 125 circulation pump 126 flow line 127 valve 128 clean in place dosing device 129 pump 130 flow line 131 flow line 132 tee fitting 133 flow line 134 tee fitting 135 valve 136 valve 137 flow line 138 flow line 139 left conduit/membrane loop conduit 140 right conduit/membrane loop conduit 141 retentate line 142 valve 143 valve 144 module of ceramic hollow fiber membranes (left) 145 module of ceramic hollow fiber membranes (right) 147 drain line 148 valve 149 sewer 150 permeate flow line 151 permeate flow line 152 permeate flow line 153 valve 154 tee fitting 155 tee fitting 156 valve 157 clean water tank/permeate tank 158 flow line 159 pH adjustment device 160 pump 161 flow line 163 flow line 164 permeate pump 165 flow line/discharge flow line 166 backwash flow line 167 valve 168 valve 169 tee fitting 170 flow line 171 valve 188 valve 196 flow outlet 198 line 199 valve 200 valve 201 flow line
[0079] All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
[0080] The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.