Patent Publication Number: US-2009223891-A1

Title: System, device and method for on-site wastewater processing

Description:
FIELD OF THE INVENTION 
     This invention relates generally to filtration devices and systems for producing clean water from sewage sources, particularly clean water from sewage stored in septic tanks. 
     BACKGROUND OF THE INVENTION 
     Effluents from septic tanks may no longer meet the new water quality emission standards now in force in various municipalities and other governmental jurisdictions. It is advantageous to have an economical solution to bring existing and current septic tank systems in conformity to the new water quality release standards. Alternatively, drainflelds often fail due to overloading. It is advantageous to have an economical solution for the remediation of failed systems. 
     SUMMARY OF THE INVENTION 
     A modular wastewater clarification device that may be positioned external to a septic tank or, alternatively, installed internally within a septic tank chamber to produce sufficiently clean water for lawn and agricultural uses. The modular clarification device includes a filter having a smaller size than the pre-filter bridging between the primary and secondary chambers of a septic tank. In one embodiment, the modular filtration unit resides outside the two-chambered septic tank and receives pre-filtered septic tank effluent fluids stored in the secondary chamber that has accumulated pre-filtered effluent. In another embodiment, the modular wastewater clarification device resides inside the secondary chamber and filters the accumulated pre-filtered effluent. The modular filtration device, having a substantially smaller pore size range than the inter-chamber pre-filter, releases clean water having substantially lowered bacterial and waste related impurities sufficient to meet water release standards suitable for lawn, garden, and agricultural uses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  schematically depicts a cross-section of a septic tank effluent wastewater processing system; 
         FIG. 2  schematically depicts a cross-section of an alternate embodiment of the septic tank effluent wastewater processing system; 
         FIG. 3  schematically depicts a cross-section of an effluent wastewater clarification device; 
         FIG. 4  schematically depicts a cross-section of a clarification device chamber; 
         FIG. 5  schematically depicts a cross-section of a two-chambered septic tank; 
         FIG. 6  schematically depicts an expansion of the wall region separating the primary and secondary waste chambers; 
         FIG. 7  schematically depicts a cross-section expansion view of the effluent wastewater pump chamber showing a sewage wastewater effluent pump, control floats and a high water alarm; 
         FIG. 8  schematically depicts a cross-sectional view of a pump house and clear clean water storage tank with distribution ports to a drain field pipe array; 
         FIG. 9A  schematically depicts side and cross-section views of an alternate embodiment of the effluent wastewater clarification device of  FIG. 3  along sectional line A-A; 
         FIG. 9B  schematically depicts side and cross-sectional views of an alternate embodiment with an external gas supply to the diffuser  22  of the clarification filtration device of  FIG. 3  along sectional line B-B; 
         FIG. 9C  schematically depicts another side and cross-sectional view of the device depicted in  FIG. 3  along sectional lines C-C; 
         FIG. 9D  illustrates an alternate embodiment of the support skirt  14  without a concrete base having fluid ports  15  and supporting the clear water filtration devices depicted in  FIGS. 9A-9C ; 
         FIG. 10  schematically depicts an alternate embodiment of the pump house and clean water distribution reservoir depicted in  FIG. 2 ; 
         FIG. 11  schematically depicts an alternate cross-sectional view of a pump house having a symmetrical array of drainage pipes; and 
         FIG. 12  schematically depicts other operational parts of the pump house  400  of  FIGS. 8 and 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE PARTICULAR EMBODIMENTS 
       FIGS. 1-12  below illustrate particular embodiments of systems and methods for on-sight wastewater processing and water-remediation. In general, a septic tank pre-filters fluids from primary waste sewage with a filter media having a first porosity. The first porosity may include pore sizes in the approximate range of 1/32 to 1/16 inch to provide a fluid effluent that has gross to medium size particulates removed above this range. The waste fluid effluent is then clarified to clean water status through a filter media having a second porosity. The filtration media within the modular filtration device may be spiral, plate and frame, or other filtration media configurations wherein the second porosity may include a pore size in the range of 0.05 to 0.1 micron diameter. The clean water permeate or filtrate is substantially reduced in bacterial count and any sub-micron indissoluble particulates to render a water quality suitable for lawn and garden, dissemination of clean water to drain fields to foster their improved functioning, and/or to provide clean water for agricultural uses. 
       FIG. 1  schematically depicts a cross-section of a septic tank effluent wastewater processing system. System  500  includes a modular clarification device  10  housed in a clarification chamber  100  located exterior to a two-chambered septic tank  200 . The two-chambered septic tank  200  includes a primary waste chamber  204  and a secondary chamber  208  that receives coarsely pre-filtered waste effluent fluids. A submersible pump assembly  300  resides in the secondary chamber  208  and delivers the pre-filtered accumulated waste effluent fluids to the clarification chamber  100 . A pump house  400 , having hydraulic and air pumps and related plumbing, controls the hydraulic and operational aspects of the clarification device  10  to deliver clean water to a storage tank located in the pump house  400  and thence to a drainage field or other destination. A recycle pipe  114  is available to route pre-filtered waste effluent fluids back to the primary waste chamber  204  during overflow conditions that may develop within the clarification chamber  100 . 
       FIG. 2  schematically depicts a cross-section of an alternate embodiment of the septic tank effluent wastewater processing system. Operating in substantially the same way as described above and below, alternate processing system  600  includes the clarification chamber  100 , with its clarification device  10 , occupying the second chamber  208  adjacent to the submersible pump device  300 . 
       FIG. 3  schematically depicts an effluent wastewater clarification device  10 . Clarification device  10  includes a support skirt  14  having at least one waste effluent access port  15  that provides pre-filtered effluent wastewater access to the bottom of the membrane filter  18 . Prefilt wastewater is directed and is routed by air bubbles produced by a diffuser  22  into channels of a spiral filter membrane  18 . Effluent wastewater is directed from the air diffuser or collection funnel  22  and routed into channels of a spiral filter membrane  18 . The spiral filter membrane  18  may include pores sizes approximately one-tenth to one-thousandth the size of the pores of the pre-filter  232  located in the waste chamber  204  as shown in  FIGS. 5-7  below. Effluent wastewater is sieved through the spiral filter membrane  18  and is outputted as clarified or clean water in through a series of delivery apertures  26  in a filtrate collection pipe  28 . The filtrate collection pipe  28  is then hydraulically coupled to a tee  30  having an air inlet port  32  and a clear water outlet port  34  from the tee  30 . A supply of air is routed through the air inlet port  32  to the funnel  22  and thence to the inlet or dirty side of the filter membrane  18 . A source of vacuum is delivered to the water outlet port  34  to the outlet side or clean side of the filter membrane  18 . As discussed more fully below, vacuum applied to the clean side of the membrane causes the urging or movement of the effluent wastewater from the dirty side of the membrane  18 , through it, and onto the clean side of the membrane  18 . The delivery of air to the dirty side of the membrane  18  provides a scrubbing or scouring action to dislodge solid material that has taken residence over and within the surface of the membrane in membrane filter  18 . Clear water then emerges from the delivery apertures  26  and thence into the collection pipe  28 . The width of the membrane  18  may be 9.3 inches and the diameter of the access port  15  may be 4 inches. The effect that these dimensions, while perhaps preferred, are not limiting. 
     The membrane filter  18  may be cylindrically shaped and include flat sheet filter media having a porosity between approximately 0.05 and 0.1 microns or other size ranges smaller than the pore ranges of the pre-filter  232 . Dimensions may vary from forty inches in length and a diameter of up to twenty-four inches. Other dimensions are possible to accommodate smaller or larger capacity and processing rates. 
       FIG. 4  schematically depicts a cross-sectional view of a clarification device chamber  100  housing the clarification device assembly  10 . The clarification device chamber  100  includes housing  108  with an air pipe  102  connected to the inlet port  32  and a clean water permeate pipe  104  connected to the outlet port  34 , and is fitted with access port cover  112 . Incoming and partially filtered wastewater effluent pumped from the submersible pump  300  assembly depicted in  FIGS. 1  above and  5  below is routed near the bottom of the clarification device chamber  100 . The incoming wastewater effluent fills the chamber  100  and reaches the activation float  38  located above the clarification device  10 . The activation float  38  upon moving engages a switch (not shown) in electrical connection to a vacuum pump  440  and air pump  446  described in  FIG. 8  below. The vacuum is then delivered to the clean side of the filter media  18  into the collection pipe  28  and then into the clean water permeate pipe  102 , and air is pumped through air pipe  104  for delivery to the dirty side of filter media  18  via the inlet port  32  and then to the funnel diffuser  22 . Clean water harvesting and storage is described below. The float level is positioned to maintain fluid levels remain above the clarification device  10  to keep the membrane media  18  sufficiently moist. 
       FIG. 5  schematically depicts a cross-section of a two-chambered septic tank  200 . Septic tank  200  includes a raw-waste reception chamber  204  and an effluent wastewater pump chamber  208 . Separating the wastewater reception chamber  204  and effluent wastewater chamber  208  is an inter-chamber wall  206 . Wastewater coming from residential or business sources is routed through inlet pipe  212  to a pipe tee baffle  214 . The raw solid and liquid waste coming from the residential or businesses accumulate within the raw waste reception chamber  204  to a level that occupies a height in which a partial filtration can begin at the raw waste fluid effluent filter  232 . The effluent filter  232  is housed in an effluent filter holder  230  and is in a fluid communication with an outlet pipe  234  that is connected between the inter-chamber wall  206 . At the top of the septic tank  200  are three riser ports for access to inspect or maintain various proponents described herein for the septic tank  200 . The riser ports include an inlet maintenance riser port  216  that has a view of the pipe tee baffle  214 , a filter maintenance riser port  220  to view the effluent filter holder  230  and to service the effluent filter  232 . A submersible pump riser port  240  is positioned over the effluent waster water pump chamber  208 . Occupying the effluent wastewater  208  is a submersible pump assembly  300 . This submersible pump assembly includes a pre-filtered outlet pipe  310 . 
       FIG. 6  schematically depicts an expanded cross-sectional view of the inner chamber wall  210  located between the raw waste chamber  204  and effluent water chamber  208 . Shown in greater detail are the effluent filter holder  230  and the effluent filter  232 . There is a three-inch layer or a three-inch distance that is located near the tee portion of the effluent filter holder  230  and shows the effluent filter  232  that is plungeable up to  40  % of the liquid depth within the raw waste chamber  204 . Gravity drives the filtration process to limit particle solid discharge through the submicron to the multi-micron pores of the spiral membrane filter  232 , in which the filtrate then is routed through the port  234  into the effluent water chamber  208 . 
       FIG. 7  schematically depicts an expanded cross-sectional view of the wastewater effluent pump assembly  300  and shows a control float  318 , an alarm float  322 , mounted to a vertically disposed outlet pipe  306 . The effluent pump assembly  300  includes the submersible pump  302  in hydraulic communication with the outlet pipe  306  and shows insulated wire connectivity with the control and alarm floats  318  and  322 . The effluent pipe  306  extends up into the internal space of the riser  240  and includes a junction box  308  to convey electrical wires to the submersible pump  302  and control and high water floats  318  and  322 . Electrical wires  332  and  328  connect to the electrical junction box  308 . The outlet pipe  306  is shown in hydraulic communication with wastewater outlet pipe  3   10 . 
       FIG. 8  schematically depicts a cross-sectional view of a pump house  400  connected with a water level alarm  401 . High fluid levels in the second chamber  208  arising from movement of the alarm float  322  indicates a failure to process water and is so announced by alarm  401 . The pump house  400  may sit upon a base  406 . 
       FIG. 9A  schematically depicts side and cross-section views of an alternate embodiment of the effluent wastewater clarification device of  FIG. 3  along sectional line A-A. Spatial arrangement of the support skirt  14  and its access port  15 , the membrane  18 , the Tee connector  30 , the air diffuser or funnel  22 , and the air inlet pipe  102  is shown. 
       FIG. 9B  schematically depicts an alternative configuration of the air supply to diffuser  22 , a side and cross-sectional view of the clarification filtration device of  FIG. 3  along sectional line B-B. 
       FIG. 9C  schematically depicts another side and cross-sectional view of the device depicted in  FIG. 3  along sectional lines C-C. 
       FIG. 9D  illustrates the plastic base skirt without concrete base having fluid ports and supporting the clear water filtration device depicted in  FIGS. 9A-9C . 
       FIG. 10  schematically depicts an alternate embodiment of wastewater processing system having the effluent chamber  208  occupied by the submersible pump assembly  300  and the clarification device chamber  100 . In this alternate embodiment, the clarification chamber  100  is shown housed in the effluent wastewater pump chamber  208  adjacent the effluent pump assembly  300 . In this embodiment, a more efficient use of space can be achieved by bundling the submersible pump assembly  300  next to the clarification chamber  108 . 
       FIG. 11  schematically depicts an alternate cross-sectional view of a pump house having a symmetrical array of drainage pipes  458   
       FIG. 12  schematically depicts other operational parts of the pump house  400  of  FIGS. 8 and 11 . The pump house  400  further includes a three-way tee manifold  436  that is connected with a clean water pump  440  that in turn is connected to a first port of tee manifold  436 . A back flush pump  442  is connected with a second port of tee manifold  436  via pipe  447 , and an air pump  446  is connected with the air pipe  102 . A clean water tank  450  is connected with the downstream or effluent side of the vacuum pump  440  and on the inlet side of the back flush pump  442  via pipes  444  and  448 . Clarified water is delivered to the upper portion of tank  450  via delivery pipe  444  and clean water used to back flush the membrane  18  is withdrawn from the bottom side of tank  450  via delivery pipe  448  connected to the inlet side of back flush pump  442 . A solenoid switch  477  is installed between tee manifold  436  and effluent pump  440 . Another solenoid switch  479  is installed between tee manifold  436  and back flush pump  442 . The solenoid switch  477  of tee manifold  436  opens and solenoid switch  479  of tee manifold  436  closes when pump  440  is energized. Alternatively, solenoid switch  477  of tee manifold  436  closes and solenoid switch  479  of tee manifold  436  opens when back flush pump  442  is energized. 
     When the system is not processing prefilt, it is in the intermittent mode. In the intermittent mode, a timer in the motor control center (not shown) energizes a blower  446  for  5  minutes followed by a fixed pause of time. The blower  446  pushes air via pipe  102  to a diffuser  22 . Pipe  102  passes through a compression fitting at port  32  of tee  30  and continues through pipe  28  in membrane filter  18  and passes through another compression fitting at the base of membrane filter  18  before connecting to the top of diffuser  22  as depicted in Figures  9 A and  9 C. When the diffuser  22  gets air, it produces bubbles, which scour the outside of the membranes in membrane filter  18 . 
     Prefilt enters through inlet pipe  212  to a tee baffle  214  and enters chamber  204  of tank  200 . The water level rises until water passes through effluent filter  232  into outlet pipe  234  in inter-chamber wall  210  into chamber  208 . The water level rises until activation float switch  318  energizes pump  302 . Pump  302  forces prefilt water into pipe  306 . Pipe  306  delivers prefilt water via pipes  310  &amp;  110  to clarification tank  108 . The water level rises in clarification tank  108  until activation float switch  38  sends a signal to the motor control center (not shown), which energizes a timer that begins the purge cycle. The excess water is returned to chamber  204  through pipe  114 . Pipe  114  connects tank  108  with compartment  204  via riser  216  and tee baffle  214 . 
     The purge cycle begins with timer in the motor control center energizing air pump  446  for a short fixed period. After the fixed time period, solenoid switch  477  of tee manifold  436  is closed and solenoid switch  479  is opened. Back flush pump  442  energizes. The outlet of back flush pump  446  connects to solenoid switch  479  via pipe  447 . Back flush pump  442  draws water from day tank  450  via pipe  448 , which connects the inlet of back flush pump  446  and day tank  450 . During the purge cycle, the back flush pump  442  pumps water via pipe  447 , pipe  104 , port  34  of tee  30  and pipe  28  to the clean side of membrane filter  18 . For a period of several minutes clean water moves backwards through the membrane inside membrane filter  18  clearing out the pores of the membrane. 
     After the purge cycle terminates the run cycle begins. Air pump  446  remains energized throughout the purge and run cycles. The timer ends the purge cycle by de-energizing back flush pump  442 , moving the solenoid in the three way tee manifold such that port  477  is open and port  479  is closed and energizing permeate pump  440 . The inlet of permeate pump  440  connects to the three way tee manifold  436  via pipe  449 . The outlet of permeate pump  440  connects to the top of the day tank  450  via pipe  444 . Water is drawn from the clean side of the membranes in membrane filter  18  by effluent pump  440  via pipe  28 , port  34  of tee  30 , pipe  104 , pipe  444 , of three way manifold tee  436  and pipe  449 . The permeate pump  440  pumps the water to the day tank  450  via pipe  444 . Day tank  450  fills until the water level reaches field delivery pipe  454 . Field delivery pipe  454  delivers the effluent to the drain field. The timer in the motor control center energizes the effluent pump for 9 minutes on and one minute off or for 8 minutes on and 2 minutes off. A preset purge cycle will initiate during the run cycle as needed. When the prefilt stops entering pipe  212  and tee  214 , the water level in chamber  204  drops below the level of filter  230 , the water level in chamber  208  falls and lowers the activation float switch  318  which de-energizes pump  302 . The water level in tank  108  drops and lowers float switch  38  which no longer sends a signal to the motor control center, blower  446  is de-energized, effluent pump  440  is de-energized and a timer begins the intermittent mode. 
     Periodically a chemical-based cleaning cycle may be applied, commonly, once or twice a year. Cleaning chemicals to the day tank  450  are introduced and a user manually controls the energizing of the pump motors of pumps  440 ,  442 , and  446  and solenoid switches  477  and  479  in the cleaning cycle. The solenoid switch  477  of tee manifold  436  closes and solenoid switch  479  of tee manifold  436  are opened. Back flush pump  442  is energized for several minutes and draws water and cleaning solution from day tank  450  using pipe  448 . The pump  442  pushes the solution into pipe  447 , solenoid switch  479 , tee manifold  436 , pipe  104 , tee  30 , pipe  28  of membrane filter  18  and through the clean side of the membranes inside membrane filter  18 . When pump  442  finishes pumping the system may be set to dormant for a period of 1 to 2 hours. Air pump  446  is de-energized during the chemical cleaning and during the dormant period. 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, more than one modular filtration device  10  can be connected in parallel to increase the flow capacity and filtration rates. Other sub-micron filters having ranges larger than or smaller than the approximately 0.05-0.1 micron range may be used in the modular clarification device to tune or adjust to the local water release specification requirements. Another clarification chamber  100  having a sub-micron filter with the same approximate 0.05-0.1 micron filter, or a filter with a range smaller than 0.05-0.1 microns may be installed, thereby establishing a three stage filtration process. For single chamber septic tanks, an external chamber coupling a 1/32- 1/16 inch pre-filter to the fluid out flows from single chamber may be installed, and then connected to a downstream located clarification chamber  100  having a sub-micron filter. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.