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SEWAGE TREATMENT PLANT
BASED ON RBC TECHNIQUE
BY :AVINASH KUMAR JHA
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INTRODUCTION
• THE ROTATING BIOLOGICAL CONTACTOR (RBC) IS A FIXED FILM BIOLOGICAL SECONDARY
TREATMENT DEVICE.
• IN OPERATION, A MEDIA, CONSISTING OF A SERIES OF CIRCULAR DISKS MOUNTED SIDE BY
SIDE ON A COMMON SHAFT IS ROTATED THROUGH THE WASTEWATER FLOW.
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STRUCTURE OF RBC
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WORKING OF RBC
• THE SHAFT CONTINUALLY ROTATES AT 2 TO 8 RPM, AND A LAYER OF
BIOLOGICAL GROWTH 2 TO 4 MM THICK IS SOON ESTABLISHED ON THE
WETTED SURFACE OF EACH DISK.
• THE DISK CONTINUES TO ROTATE, LEAVING THE WASTEWATER AND MOVING
THROUGH THE AIR. DURING THIS TIME, OXYGEN IS TRANSFERRED FROM THE AIR
TO THE SLIME. AS THE SLIME REENTERS THE WASTEWATER, EXCESS SOLIDS AND
WASTE PRODUCTS ARE STRIPPED OFF THE MEDIA AS SLOUGHINGS. THESE
SLOUGHINGS ARE TRANSPORTED WITH THE WASTEWATER FLOW TO A
SETTLING TANK FOR REMOVAL.
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INFERENCE DURING OPERATION
• DURING OPERATION, OBSERVATIONS OF THE RBC MOVEMENT, SLIME COLOR,
AND APPEARANCE ARE HELPFUL IN DETERMINING SYSTEM PERFORMANCE;
THAT IS, THEY CAN INDICATE PROCESS CONDITIONS. IF THE UNIT IS COVERED,
OBSERVATIONS ARE USUALLY LIMITED TO THAT PORTION OF THE MEDIA THAT
CAN BE VIEWED THROUGH THE ACCESS DOOR.
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OBSERVATIONS DURING OPERATION
• THE FOLLOWING MAY BE OBSERVED
• GRAY , SHAGGY SLIME GROWTH - INDICATES NORMAL OPERATION
• REDDISH BROWN, GOLDEN SHAGGY GROWTH - NITRIFICATION
• WHITE CHALKY APPEARANCE - HIGH SULFUR CONCENTRATIONS
• NO SLIME - SEVERE TEMPERATURE OR PH CHANGES
REF: TREATMENT OF MUNICIPAL WASTEWATER BY USING ROTATING BIOLOGICALCONTRACTORS (RBC’S)
PRASHANT A.KADU, AMRUTA A.BADGE, DR.Y.R.M.RAO ( AJER )
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ORGANIC AND NITROGEN REMOVAL IN RBC
• FIRST DAY COD LEVEL REMAINS LOW IN THE EFFLUENT BUT AFTER A PERIOD OF
75-100 DAYS EFFLUENT QUALITY START DETERIORATING AS A RESULT OF
WASHOUT OF DETACHED BIOMASS.
• SOME BACTERIA LIKE PSEUDOMONAS REMOVED FROM FIXED FILM SYSTEM AS
THEY DO NOT STICK ON THE FILM .
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Performance of RBC in COD and NH4-N removal
• IN AEROBIC UNIT COD REMOVAL AFFECTED BY THE HYDRAULIC LOADING .IT
FIRSTLY DECREASE UPTO A CERTAIN LEVEL AS SHOWN :
• intense separation of the attached biomass occurred contributing
to high effluent COD values, and the low removal efficiency was
the result of biosolids escape rather than inadequacy of
the unit at this high loading
• Nitrification efficiency firstly increase and then becomes constant
Ref: Organic and nitrogen removal rotating biological contactor treating
municipal wastewater
Demetrios N. Hiras, Ioannis D. Manariotis, Sotirios G. Grigoropoulos
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NITRIFICATION AND DE-NITRIFICATION
• NITRIFICATION-DE-NITRIFICATION IS ONE OF THE MOST WIDELY ACCEPTED BIOLOGICAL
SOLUTIONS TO THE PROBLEM OF NITROGEN REMOVAL FROM HIGH STRENGTH
NITROGENOUS WASTEWATERS DUE TO ITS EFFICIENCY AND ECONOMY.
• NITRIFICATION IS A TWO STEP SEQUENTIAL AEROBIC OXIDATIVE PATHWAY FOR THE
OXIDATION OF AMMONIA TO NITRATE, RESULTING IN RELEASE OF ENERGY.
• THE REACTION IS CARRIED OUT BY AUTOTROPHIC BACTERIA BELONGING TO THE GENERA
NITROSOMONAS (OXIDIZING AMMONIA TO NITRITE) AND NITROBACTER (OXIDISING
NITRITE TO NITRATE).
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NITRIFICATION AND DE-NITRIFICATION
• DE-NITRIFICATION IS AN ANOXIC\ANAEROBIC REDUCTIVE PATHWAY FOR THE CONVERSION
OF NITRATE TO NITROGEN GAS.
• THIS REACTION IS CARRIED OUT BY BACTERIA BELONGING TO GENERA
PSEUDOMONAS, ACHROMOBACTER, MICROCOCCUS, ETC
BACILLUS,
• HOWEVER SIMULTANEOUS NITRIFICATION- AEROBIC DE-NITRIFICATION SYSTEM IN A
SINGLE STAGE USING A MIXED BIOFILM CULTURE OF THIOSPHAERA PANTOTROPHA CAN
ALSO BE USED. THUS ELIMINATING THE REQUIREMENT OF A SEPARATE ANOXIC REACTOR
FOR DE-NITRIFICATION.
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EFFICIENCY OF NITRIFICATION AND DE-NITRIFICATION
• ON THE BASIS OF HRT : REMOVAL EFFICIENCY INCREASE WITH INCREASE OF HRT
• ON THE BASIS OF SURFACE LOADING : REMOVAL EFFICIENCY DECREASE WITH INCREASE
SURFACE LOADING
• THE PH WAS MAINTAINED BETWEEN 7.8-8.5 WHICH IS IN OPTIMUM FOR BOTH NITRIFICATION
AND DENITRIFICATION
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Ref: journal on Simultaneous nitrification‐de-nitrification in a rotating biological
contactor by
Mr. S.K. Gupta, S.M. Raja & A.B. Gupta
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DECOLOURIZATION IN RBC
• COLOURED INDUSTRIAL EFflUENTS CAN BE EFFECTIVELY TREATED BY IMMOBILIZED
PHANEROCHAETE CHRYSOSPORIUM IN A CONTINUOUSLY OPERATED RBC REACTOR
FOLLOWING ITS DILUTION WITH MEDIA CONTAINING NUTRIENTS AND SUGAR, PREFERABLY
GLUCOSE.
• COD REMOVAL EFfiCIENCIES IN THE VARIOUS STAGES OF OPERATION IN THE REACTOR WERE
ALSO FOUND TO MATCH WELL WITH THE DECOLOURIZATION OF THE WASTEWATER
REF: CONTINUOUS TREATMENT OF COLOURED INDUSTRY WASTEWATER IN A ROTATING
BIOLOGICAL CONTACTOR REACTOR
KANNAN PAKSHIRAJAN ,SUMEET KHERIA
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APPLICABILITY
• RBC CAN ACHIEVE A HIGH REMOVAL OF BIODEGRADABLE ORGANIC WASTE FROM DOMESTIC
BLACK OR GREY WATER AS WELL AS FROM INDUSTRIAL WASTE WATER AS FROM DYE
INDUSTRY
• IT HAS BEEN OBSERVED THAT THE ORGANIC REMOVAL IS DECREASED SIGNIFICANTLY IF
ORGANIC LOADING IN MORE THAN 5 AND FULL NITRIFICATION CAN BE ACHIEVED WHEN THE
HYDRAULIC LOADING IS LESS THAN 5gmbod/m2.day .
• SO TO GET MAXIMUM APPLICATION THE LOADING SHOULD BE IN SOME LIMITS.
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ADVANTAGES OF RBC UNIT
• SHORT CONTACT PERIOD ARE REQUIRED DUE TO LARGE ACTIVE SURFACE AREA.
• CAPABLE OF HANDLING OF WIDE RANGE OF FLOWS.
• SLUDGE HAS GOOD SETTLING CHARACTERISTICS.
• LOW POWER REQUIRED.
• SIMPLE IN OPERATION AND MAINTENANCE
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DISADVANTAGES
• REQUIREMENT FOR COVERING RBC UNIT TO PREVENT ALGEA GROWTH AND FREEZING IN
NORTHERN PART OF INDIA.
• SHAFT BEARING AND MECHANICAL DRIVE UNITS REQUIRE FREQUENT MAINTENANCE.
• CONTINUOUS SUPPLY OF ELECTRICITY REQUIRED.
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REFERENCES
• TREATMENT OF MUNICIPAL WASTE WATER USING ROTATING BIOLOGICAL CONTACTOR
BY PRASHANT A KADU , AMRUTA A BADGE
• ORGANIC AND NITROGEN REMOVAL IN A TWO-STAGE ROTATING BIOLOGICAL CONTACTOR TREATING MUNICIPAL
WASTEWATER
BY : DEMETRIOS N. HIRAS, IOANNIS D. MANARIOTIS, SOTIRIOS G. GRIGOROPOULOS
• SIMULTANEOUS NITRIFICATION‐DENITRIFICATION IN A ROTATING BIOLOGICAL CONTACTOR
BY : S.K. GUPTA , S.M. RAJA & A.B. GUPTA
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REFERENCES
• A PERFORMANCE EVALUATION OF A FULL SCALE ROTATING BIOLOGICAL CONTACTOR (RBC) SYSTEM
BY : M.Y. NOROUZIAN & S. GONZALEZ-MARTINEZ
• EFFECT OF OPERATING PARAMETERS ON DENITRIFICATION IN ANANOXIC ROTATING BIOLOGICAL CONTACTOR
BY : SUSANA CORTEZ PILAR TEIXEIRA ROSÁRIO OLIVEIRA & MANUEL MOTA
• CONTINUOUS TREATMENT OF COLOURED INDUSTRY WASTEWATER USING IMMOBILIZED PHANEROCHAETE CHRYSOSPORIUM
IN A ROTATING BIOLOGICAL CONTACTOR REACTOR
BY: KANNAN PAKSHIRAJAN, SUMEET KHERIA
THANK YOU