Grey Water Processing Unit

DISCLAIMER – ATTENTION

PLEASE DO NOT TRY TO CREATE THIS AT HOME – THIS IS A CONCEPT ONLY AND BEFORE ATTEMPTING TO DISCHARGE ANY GREYWATER OUTSIDE OF THE SEWER, YOU MUST CONSULT YOUR LOCAL HEALTH AND ENVIRONMENT STANDARDS AGENCY AND HAVE ALL WORK CARRIED OUT BY A PLUMBER IN ACCORDANCE WITH LOCAL REGULATIONS AND STANDARDS.

THE PROBLEM

IN 2016 NEARLY A BILLION LITRES OF WATER WAS REPORTED TO ENTER THE SEWER NETWORK EVERY DAY. THIS WATER IS OF VARYING QUALITY AND CONTENT WHICH ALL NEEDS TREATING TO MAINTAIN PUBLIC AND ENVIRONMENTAL HEALTH.

IF THE POPULATION KEEPS EXPANDING THEN WE WILL NEED MANY MORE SEWAGE TREATMENT CENTRES AND UPGRADE SEWER NETWORKS.

HOW CAN WE BALANCE INFRASTRUCTURE INVESTMENT WITH COST

WE NEED TO UNDERSTAND WHY ARE WE TREATING USED WATER AND WHY DOES IT ALL NEED TO GO TO A TREATMENT CENTRE.

WE TREAT USED WATER TO PREVENT DISEASE AND DAMAGE TO THE PEOPLE AND ENVIRONMENT BUT THIS IS CLASSED IN DIFFERENT WAYS. THE TWO MAIN CATEGORIES ARE GREY AND BLACK.

BLACK BEING THE WORST AND THIS MUST BE TREATED PROPERLY AS IT CONTAINS FEACAL COMPONENTS THAT ARE HAZARDOUS TO HEALTH AND ARE REGULATED.

GREY WATER IS WASHING WATER I.E. SOAPS AND BODY WASHING. THERE ARE MANY SYSTEMS THAT CAN RECYCLE YOUR SHOWER WATER ETC BUT THESE ARE A NICE LITTLE COST. THERE IS ONE ASPECT OF WASHING WATER AS IT CONTAINS SMALL AMOUNTS OF BLACK WATER WHICH ARE FROM YOUR BODY AND FATS.

SO WHAT HAPPENS TO OUR SEWAGE WHEN IT LEAVES OUR HOME?

SEWAGE IS TRANSPORTED THROUGH AN INVENTORY OF SEWERS AND PUMPING STATIONS WHICH MOVE IT TO TREATMENT CENTRES. IT FLOWS UNDER GRAVITY TO THE PUMPING STATION AND IS THEN PUMPED UP A PIPE OVER THE HIGH POINT OF THE CATCHMENT BOWL INTO THE NEXT CATCHMENT BOWLS NEAREST HIGH POINT TO GRAVITATE DOWN TO ANOTHER PUMPING STATION UNTIL IT IS FINALY PUMPED TO A TREATMENT CENTRE.

AT THE TREATMENT CENTRE SEWAGE IS PROCESSED AND RETURNED AS 2 MAIN PRODUCTS, SLUDGE AND EFFLUENT.

SLUDGE IS THE BIOMASS REMOVED FROM THE SEWAGE AND IS DIGESTED TO CREATE METHANE WHICH POWERS A CHP AND PROVIDES POWER TO THE ELECTRICITY GRID.

EFFLUENT IS THE DISCHARGED TREATED LIQUID WHICH IS DISCHARGED INTO A WATER COURSE OR SEA.

SO HOW CAN WE MAKE THIS MORE EFFICIENT AND CHEAPER?

MANY OF YOU WILL BE FAMILIAR WITH LEAN SIX SIGMA AND THE 7 WASTES (TRANSPORTATION,INVENTORY,MOTION,WAITING,OVERPROCESS,OVERPRODUCTION AND DEFECTS (TIMWOOD))

SO LETS IDENTIFY WHAT SEWAGE IS AND THEN SEE WHAT WE CAN DO. THE INFORMATION FROM THE UK ENVIRONMENT AGENCY WEBSITE (FIGURES OF 2014) AVAILABLE REGARDS HOW DOMESTICLY SUPPLIED WATER IS USED. SO LETS USE THIS AS A GUIDE.

26% IS TOILET WASTE – ABSOLUTELY ESSENTIAL TO BE TREATED

7% IS OUTDOOR WASTE FROM WASHING CARS OR WATERING THE LAWNS. THIS IS CLEAN WATER SO NO

67% IS FROM WASHING PROCESSES – PERSONAL AND CLOTHES WASHING. THIS IS GREY WATER BUT CONTAINS SOME BLACK POLLUTANTS LIKE BIOWASTE. THE REST – WATER, SOAPS, FOG’s AND PLASTIC COULD BE PREVENTED FROM ENTERING THE SEWER.

THERE HAVE BEEN MANY PRODUCTS PRODUCED TO HARVEST THIS GREYWATER, BUT TILL NOW THEY HAVE BEEN SEEN AS THE LAST RESORT OPTION AS THEIR COST OF UPTO £3000 IS PROHIBITIVE IN A RETURN ON INVESTMENT MODEL.

THIS PROTOTYPE UNIT COST NEAR £40.

THE ONS STATED IN (ACCURATE 2016) THERE ARE 26.703M HOUSEHOLDS IN THE UK, YOU CAN SEE THAT’S A LOT OF WATER.

67% OF THIS WATER MAY CONTAIN FATS OIL GREASES (FOG) SO IF WE CAN CATCH THE FOG THEN WE ARE ONTO A WINNER IN TERMS OF SAVING MONEY ON FIGHTING FOG BLOCKAGES AND POLLUTIONS.

NOW CONSIDERING THAT SINCE 2002-2014, THERE HAVE BEEN 2.126M HOMES BUILT WITH SOAKAWAYS AS A FIRST OPTION FOR DRAINAGE, THERE IS NOW THE OPTION TO DISPOSE OF THIS FILTERED AND SEPERATED GREY WATER UNDERGROUND TO BE FINAL FILTERED BY NATURE. NO FURTHER PROCESSING REQUIRED.

WHAT MUST THE DESIGN CRITERIA BE OF A SOLUTION?

IT MUST SEPERATE BIOSOLIDS AND RELEASE THEM INTO THE SEWERAGE SYSTEM

SEPARATE FOG’s AND PLASTIC FROM THE SEWERAGE AND GREYWATER

ALLOW GREYWATER TO BE PIPED TO A SOAKAWAY GUTTER DRAIN IF POSSIBLE

BE ABLE TO BE RETROFITTED WITH NO RISK OR ENTRY TO CUSTOMERS HOMES OR BUSINESSES (NO RISK OF INTERNAL FLOODING IF FAILS)

TO BE ABLE TO BE EXPANDED ON FOR HARVESTING AS A POTENTIAL FUTURE END USER OPTION

BELOW IS MY WORKING PROTOTYPE

UNIT OPERATION

THE WASTE WATER FROM THE PREMISES FLOWS OUT OF THE HOME AND INTO THE TANK.

ONCE ENTERING THE TANK THE WATER VELOCITY IS SLOWED ALLOWING THE SEPERATION OF FATS,OIL,GREASE (FOG) AND BIOSOLIDS. THE FOG FLOATS TO THE TOP OF THE TANK AND THE SOLIDS SINK TO THE BOTTOM.

THE WATER NOW PASSES THROUGH A FILTRATION MEDIA OF 10MM GRAVEL AND OUT OF THE UNIT EITHER TO DRAIN OR SOAKAWAY FOG, PLASTIC AND SOLIDS FREE.

AS SOON AS THERE IS TOO MUCH SLUDGE (SOLIDS) IN THE TANK, THE LEVEL WILL RISE AND LIFT THE FLOAT WHICH OPENS THE DRAIN WHERE THE SLUDGE FLOWS TO THE SEWER. WHEN THE LEVEL DROPS, THE VALVE CLOSES AND GREY WATER AGAIN FLOWS THROUGH THE NOW BACKFLUSHED MEDIA.

(THIS VALVE CAN ALSO BE OPERATED BY BUTTON TO ALLOW FOR CLEANING)

IN CASE OF FAILURE THERE IS AN OVERFLOW TO THE SEWER OUTLET.

THE REMOVAL OF FOG AND PLASTIC FROM THE UNIT IS SIMPLY PERFORMED BY TURNING THE FOG TAP WITH A USED MILK BOTTLE UNDERNEATH.

I SUGGEST USING A MILK BOTTLE AS THESE ARE RECYCLABLE AT CIVIC AMMENITY RECYCLING CENTRES WHERE YOU CAN ALSO RECYCLE FOG. ALTERNATIVELY, IF THIS CAUGHT ON, THEN FOG COLLECTION COULD BE PART OF THE RECYCLING ROUND LIKE FOOD WASTE AND TURNED INTO FUEL.

THE BENEFITS

SO FOR A UNIT COSTING ABOUT £40 OFF THE SHELF (POSSIBLY LESS IF MANUFACTURED IN MASS) WE WILL GAIN

CLEANER SMELLING TOWNS AND CITIES

REDUCED ENERGY CONSUMPTION BY ALL WATER RECYCLING COMPANIES HELPING THE NATIONAL GRID ENERGY CAPACITY ISSUES. A DROP IN AT LEAST 60% FLOW IN THE SEWERS AND THROUGH TREATMENT WILL CREATE A MASSIVE ENERGY SURPLUS ON THE GRID.

LOWER CO2 FROM CONSTRUCTION DUE TO THE INCREASE IN NETWORK CAPACITY

LESS POLLUTION OF WATERCOURSES, FLOODINGS, VEHICLE EMMISIONS

LESS CHEMICALS DISCHARGED FROM WRC’S IN THE TREATMENT PROCESS.

LESS SURFACTANTS TO BE TREATED AT TREATMENT CENTRES MEANING LESS ENERGY INTENSIVE TREATMENT PROCESSES CAN BE USED.

THE LIST GOES ON BUT ESSENTIALY A CLEAN STABLE ENVIRONMENT FOR OUR CHILDREN.

I DID PRESENT THIS AT AN INNOVATION EVENT IN 2016 BUT HAVE YET TO HAVE MY IDEA COME TO FRUITION.