Patent Application
20180347100
Not applicable
Not applicable
The present invention relates to an improved method and apparatus for treating laundry (e.g., commercial or industrial or other) that features first and second treatment vessels that generate permeate and retentate streams, wherein the retentate stream is combined with a polymer and solidified for disposal.
Textile washing performed in commercial laundries typically consumes between about 2.5 to 25+ liters of waste water for each kilogram of articles or goods to be washed. Current technologies using ceramic filters and reverse osmosis have been used to treat the waste water to be reused in the washing process. However, these prior art systems produce highly concentrated (BOD (Biological Oxygen Demand), COD (Chemical Oxygen Demand), TDS (Total Dissolved Solids), and TSS (Total Suspended Solids)) waste referred to as retentate. The result is a significant quantity of retentate typically about 0.5 to 5 L/Kg. In certain applications the retentate can be twice as high. As an example, a laundry washing 20 million kilograms of linen per year would generate between 10 to 100 million liters of retentate. This retentate must be treated by a municipal potable water treatment facility.
U.S. Provisional Patent Application Ser. No. 62/514,828, filed 3 Jun. 2017, is hereby incorporated herein by reference. U.S. Provisional Patent Application Ser. No. 62/514,828 on page 9, lines 7-8, states that the wall of each hollow ceramic fiber can be between about 2 and 4 mm thick. The thickness of the wall of each hollow ceramic fiber can preferably be between about 1 and 4 mm thick. U.S. Provisional Patent Application Ser. No. 62/514,828 on page 9, line 31, states that each hollow ceramic fiber has a polymeric coating on the tube wall. Preferably, each hollow ceramic fiber can have a polymeric, metal oxide, or graphene oxide coating on the tube wall, wherein the metal oxide can be for example an aluminium oxide, zirconia oxide or titanium oxide.
The following table lists patents (each hereby incorporated by reference) directed to commercial washing systems such as tunnel washing machines.
A laundry washing 20 million kilograms of linen per year generates between 10 to 100 million liters of retentate. This retentate must be treated by a municipal potable water treatment facility.
Using a combination of hollow fiber ceramic filters, the retentate is reduced to 0.1 to 0.5 liters per kilogram. In the example above, the 20M kilos washed would only produce 800,000 liters of annual retentate. This invention further treats the retentate with environmentally friendly polymers to make the retentate into a disposable solid. Thus, no discharge is produced to the municipal potable water treatment facility.
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 preferably 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 preferably separated into a permeate stream and a retentate component. The permeate stream or “permeate” is the water that has been treated by the membrane. The retentate component (that which is retained by the filter) is transmitted to a second treatment unit that filters particles of between about 3 and 10 nanometers. The permeate stream from this second treatment unit is 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.
In one embodiment, a second permeate flow stream can discharge from the second treatment vessel/unit.
In one embodiment, the retentate component can be reduced to between about 0.1 and 0.5 liters per kilogram.
In one embodiment, the filtered permeate stream can have a chemical biological oxygen demand that was reduced by about ninety percent (90%).
In one embodiment, the filtered permeate stream can have total suspended solids that was reduced by about ninety-six percent (96%).
In one embodiment, the filtered permeate stream can have turbidity that was reduced by about ninety-eight percent (98%).
In one embodiment, the filtered permeate stream can have a non-detectable level of E-Coli.
The present invention includes a method of treating a commercial laundry waste stream. The commercial laundry waste stream can be discharged from one or more commercial washing machines, wherein the waste stream can include one or more of suspended solids, dissolved solids, and CBOD (chemical biological oxygen demand). The waste stream can be transmitted to a first treatment unit that can have a membrane filter that filters particles of between about 20 and 200 nanometers (nm). The waste stream can be separated into a permeate stream and a retentate component, wherein the retentate component can be smaller than the permeate component. The retentate component can be transmitted to a second treatment unit that preferably filters particles of between about three and twenty (3-20) nanometers. The permeate stream can be transmitted to a permeate holding vessel. The retentate component can be mixed in a mixing vessel with a polymer, or polymer blend to preferably form a solid waste.
In one embodiment, the filtered permeate stream can have a chemical biological oxygen demand (BOD) that is preferably reduced by over seventy percent (70%).
In one embodiment, the filtered permeate stream can have total suspended solids (TSS) that was preferably reduced by over seventy percent (70%).
In one embodiment, the filtered permeate stream can have turbidity that was preferably reduced by over seventy percent (70%).
In one embodiment, one of the treatment units can include a bundle of at least 200 hollow fiber ceramic membranes.
In one embodiment, the polymer or polymer blend can be composed of mixtures of superabsorbent polyacylate polymers with inorganic clays.
In one embodiment, the polymer or polymer blend can be bentonite clay.
In one embodiment, the superabsorbent polyacrylate—clay mixtures can contain about 30% to 80% superabsorbent polyacrylate.
In one embodiment, 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 mg/L, 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.
The present invention includes a method of treating a commercial laundry waste stream. The commercial laundry waste stream can be discharged from a commercial washing machine, wherein the waste stream includes one or more of suspended solids, dissolved solids, and CBOD (chemical biological oxygen demand). The waste treatment unit can be transmitted wherein the waste stream is preferably treated with a filter to remove particles of between about twenty and two hundred nonometers. The waste stream can be separated into a permeate stream and a retentate component. The retentate component can be transmitted to a second treatment unit that removes particles of a second size that is preferably between about three and twenty (3-20) nanometers. The permeate stream can be transmitted to a permeate holding vessel. The retentate component can be solidified by combining the retentate component with a polymer.
In one embodiment, each hollow fiber ceramic filter can be tubular, having a central longitudinal bore.
In one embodiment, the permeate stream can be comprised of non-detectable levels of E-Coli and turbidity of less than one (1) nephelometric turbidity units (N.T.U.).
In one embodiment, there are preferably multiple modules, each module can have a bundle of hollow fiber ceramic membrane.
In one embodiment, both of the treatment units can includes a bundle of at least 200 hollow fiber ceramic membranes.
In one embodiment, there can be a plurality of said bundles.
In one embodiment, at least some of the bundles can be vertically stacked one upon the other and wherein the flow stream preferably flows from a lower of the bundles to an upper of the bundles.
In one embodiment, the ceramic membranes can include multiple pairs of risers, each of the pair of risers can be connected with one or more elbow fittings.
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:
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.
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 (C3H3NaO2)n or potassium polyacrylate [—CH2—CH(CO2K)—]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.
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.
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.
The following are examples of clay-polymer composite mixtures of the present invention and effluent characteristics.
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.
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.
c. The polymer blend can be formulated to the retentate water quality characteristics such as total dissolved solids or conductivity.
d. Example superabsorbent polyacrylate—clay mixtures can contain about 30% to 80% superabsorbent polyacrylate.
e. Such polymer blends may reduce application cost.
Retentate is generated from Treatment Module No. 2 (20, 145) by filtering the reject produced Treatment Module No. 1 (15, 144).
Example of raw wastewater and Treatment Module No. 2 (20, 145) Retentate characteristics:
The filtration device/skid 40, 70 in
In
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
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.
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
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
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.
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.
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.
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.
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.
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.
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 (Al2O3) substrate material. Selective pore sizes of the aluminium oxide substrate material (Al2O3) can be about 50 to 1400 nanometers, also but not limited to selective pore sizes of the aluminium oxide substrate material (Al2O3) 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.
The following is a list of parts and materials suitable for use in the present invention:
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.
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.
This application claims benefit of U.S. Provisional Patent Application Ser. No. 62/514,834, filed 3 Jun. 2017; and U.S. Provisional Patent Application Ser. No. 62/514,828, filed 3 Jun. 2017, each of which is hereby incorporated herein by reference. Priority of U.S. Provisional Patent Application Ser. No. 62/514,834, filed 3 Jun. 2017; and U.S. Provisional Patent Application Ser. No. 62/514,828, filed 3 Jun. 2017, each of which is hereby incorporated herein by reference, is hereby claimed.
| Number | Date | Country | |
|---|---|---|---|
| 62514834 | Jun 2017 | US | |
| 62514828 | Jun 2017 | US |
