Water consumption and power consumption analysis of sewage treatment plant

By July 19, 2017 Engineering

1. Introduction:

Water ‘s alone Characteristics and its indispensable Role for all life have inspired myths and influenced civilizations, faiths, art, and literature through all times.

The procedure involved for the RBC Biological Treatment method is named as FIXED FILM ROTATING BIOLOGICAL CONTACTOR BIOWHEELS. In this procedure by agencies of rotary motion of the bio wheels micro – beings are expected to growing in the RBC and the flood from the Lamella clarifier will be the first phase of the treated H2O. The micro beings will develop on the surface of the disc and the colonisation of the beings will take topographic point because of the recess burden into the system. The thick movie like formation in the surface of the disc is the indicant of the growing. In Sewage H2O the chief components of Pollutants being organic in nature these can be digested easy in the RBC.

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Sewage is created by establishments, abodes, and infirmaries and commercial and industrial constitutions. Raw influent of sewerage effluent includes household waste liquid from the lavatories, sinks, showers, kitchens, baths, and so forth that is disposed of sewerage waste H2O.

1.1 Purposes:

The purpose of the undertaking is to Analysis of H2O ingestion and power ingestion of sewerage intervention works.

1.2 Aim:

* To Analysis the H2O and power ingestion of the sewerage intervention works

* To change the parametric quantities of H2O beginning, power beginning.

* To Analyze the Rotating Biological contactor Biowheels.Lamella clarifier

* Analyzing 2D design of the Sewage Treatment Plant.

* To analyse the consequences and propose appropriate solution.


Waste H2O collected from domestic and industrial communities must be returned to having Waterss or to the land. Although the collection of storm H2O and drainage day of the months from ancient times the aggregation of waste H2O can be traced merely to the early 1800s. The systematic intervention of effluent followed in the late 1800s and early 1900s.

There are many methods and procedures to handle effluent. The most common attack uses primary intervention ( testing and elucidation ) to take solids ; aerobic, suspended growing, activated sludge secondary intervention to cut down organic pollutants ; and chlorine disinfection to cut down pathogens. Secondary intervention is the largest energy consumer ( 30 to 60 % of entire works use ) , followed by pumping and sludge processing. Although suspended growing, activated sludge is the most common effluent intervention procedure, it is non the most energy efficient.

Aerated lagunas, dribbling filters and revolving biological contactors are significantly more efficient. They are non as widely used because aerated lagunas require a big land country, and dribbling filters and revolving biological contactors are better suited for smaller capacity applications. Many effluent intervention workss are switching from chlorine-based disinfection to UV disinfection to extinguish the hazard of storage and handling of toxic chemicals. Although UV disinfection is energy intensive, it adds no chemical residue to the wastewater. This characteristic is peculiarly of import for discharge to sensitive aquatic environments or for effluent reuse. In general, low force per unit area UV systems are well more efficient than average force per unit area systems.

Energy efficiency chances in effluent intervention include the usage of all right bubble diffusors, dissolved O control of aeration, high efficiency blowers, variable frequence thrusts on pumps and blowers, premium efficiency motors, and the decrease of the caput against which pumps and blowers operate. Sewage is by and large a mixture of domestic of waste H2O from bath, sinks and rinsing machines and lavatories, waste H2O from all industry and rainwater overflow from roads and other surfaced countries.

Every twenty-four hours in the UK about 347,000 Kilometers of cloacas collect over 11 Billion litres of waste H2O. This is treated about 9000 sewerage intervention works before the treated wastewater is discharged to inland Waterss, estuaries and the sea.

Without suited intervention, the waste H2O we produce every twenty-four hours would damage the H2O environmental and creates to impact the public wellness jobs. Untreated sewerage contains organic affair saccharides, fats and proteins, bacteriums and chemicals. Bacteria of course present in environmental Waterss do interrupt these substances down, but in making so they use the O dissolved in this H2O. If there were big or uninterrupted untreated discharges of urban waste H2O the consequence could be excessively small O for fish and other aquatic life to last. So the intent of waste H2O intervention is to take organic substances to protect the environment from these effects. Sewage works hence reproduce what would be happening in the environmental. Settling out much of the solid affair is called Primary Treatment, and utilizing Bacteria that digest and interrupt down the organic substances is called Secondary Treatment.

Sometimes farther intervention Tertiary is required to protect sensitive H2O environments ; Tertiary intervention can affect disinfecting the treated wastewater to protect the bathing and shellfish Waterss. It can besides affect the remotion of phosphoric or nitrates foods present in sewerage. To protect the Waterss that is threatened by eutrophication. ( ref sewerage intervention in the UK defray section for environment nutrient & A ; Rural personal businesss, PB 6655 March 2002. ) .


Municipal H2O usage is by and large divided into four classs,

1. Domestic H2O usually used for healthful and general intents

2. Industrial H2O used for nondomestic intents,

3. The Public service H2O usually used for fir combat, and system care and besides municipal landscape irrigation.

4. Unaccounted for system losingss and escape

The undermentioned informations are typical municipal H2O usage in the United States Report.

( ( George Tchobanoglous and Franklin L. Burton, 1991 )

Table 1 Municipalities H2O usage

3.1 Domestic H2O usage: .

Domestic H2O usage encompasses the H2O supplied to residential countries, and commercial territories, institutional installations, and recreational installations as a measured by single H2O metres.The utilizations to which this H2O is put include imbibing, rinsing, bathing, culinary, and waste remotion, and yard irrigating these sort of H2O collected from family sewerage. Using the mean flow values reported in above tabular array of the H2O used in a municipal H2O supply system is for domestic intents.

3.2 Residential countries:

The H2O usually used by residential families consists of H2O for interior usage such as showers and lavatories and H2O for exterior usage such as lawn lacrimation and auto lavation, the family effluent largely used in sewerage intervention works. Typical information for interior H2O usage are presented in below tabular array.

How much sum of H2O used in residential countries H2O usage for exterior applications varies widely depending upon the geographic location, clime and clip of twelvemonth and chiefly consists of landscape irrigation.

The Residential countries 100 % of H2O usually used by typical distribution of residential interior H2O use the undermentioned tabular array given inside informations

Table 2 Typical distribution interior H2O usage

( George Tchobanoglous and Franklin L. Burton, 1991 )

3.3 Commercial installations:

The H2O used by commercial installations for healthful intents will change widely depending on the type of activity means illustration of offices and compared to a eating house. Typical H2O usage values for assorted types of commercial installations are reported in following tabular array besides for big commercial H2O utilizing installations such as washs and auto washes, careful estimations of existent H2O usage should be made.

Table 3 Typical rates of H2O usage for commercial installations

( George Tchobanoglous and Franklin L. Burton, 1991 )

3.4 Institutional installations:

Water used by installations such as infirmaries, schools and remainder place is normally based on some step of the size of the installation and the type of lodging map provided illustration of per pupil or per bed, and H2O usually use for schools will change significantly depending on whether the pupils are housed on campus or are twenty-four hours pupils. The representative H2O usage values for institutional installations are reported following tabular array.

Table 4 Typical water-use values for institutional installations

( George Tchobanoglous and Franklin L. Burton, 1991 )

3.5 Recreational Facilities:

The recreational installations largely H2O used in such as swimming pools, bowling back streets, and cantonments, resorts, so state nines perform a broad scope of maps affecting H2O usage. The following table typical H2O usage values are reported.

Table: Typical water-use values for recreational installations

( George Tchobanoglous and Franklin L. Burton, 1991 )



Sewage intervention works there are two chief types of biological reaction, depending upon the presence or absence of free O, the aerophilic reaction takes topographic point merely in the presence of free O and produces stable, comparatively inert terminal merchandises. Anaerobic reaction are more complex, being two phase, continuing comparatively easy and taking to stop merchandises which are unstable and which still contain considerable sums of energy. In any biological reaction the energy in the organic affair, used as nutrient by the micro-organisms, is disconnected three ways ; some is used in making new micro-organisms, some is incorporated in the terminal merchandises of the reaction, the proportions of energy in the three countries depend upon the nature of the reaction, the type of organic affair, the type of micro-organisms, and environmental conditions. The organic affair in effluent therefore provides the well as supplying the energy for the oxidization reactions which releases the terminal merchandises of biological intervention. ( THY Tebbutt,1990 ) .

Domestic sewerage satisfies all these demands but some industrial effluents may be missing in foods or other factors, which could ensue in suppression of biological activity, Toxic substances present in the effluent can besides intend that biological intervention of an organic effluent is uneffective, although it is sometimes possible for micro-organism to go acclimated to substances which ab initio appear to be toxic. The purpose of conventional biological intervention processes is to accomplish about complete remotion of the organic affair in the provender. The activated sludge system is a common signifier of spread growing reactor, and both systems require a subsiding installation to take the extra biological solids produced in the procedure. In the instance of fixed movie systems the solids are basically dead cells, but with the spread growing activated sludge systems the majority of the cells are populating and are returned to the reactor for rhenium usage, merely the extra solids being removed. ( THY Tebbutt,1990 ) .

Characterstics of waste H2O sewerage intervention works:

A· Bio chemical O demand

A· Total dissolved solids

A· Chemical O demand

A· Total suspended solids


A· Bio chemical O demand:

It is a step of the sum of O that bacteriums will devour while break uping organic affair under aerophilic conditions.

A· Total dissolved solids:

It comprises inorganic salts and little sums of organic affair that are dissolved in H2O. The rule components are normally the captions, Ca, Mg, Na, and K and the anions carbonate, hydrogen carbonate, chloride, sulfate and peculiarly in groundwater nitrate.

A· Chemical O demand:

It is a step of the entire measure of O required to oxidise all organic stuff into C dioxide and H2O.

* Total suspended solids:

It is a step of the suspended solids in waste H2O, wastewater, or H2O organic structures determined by trials for “ Entire suspended non-filterable solids ” .

A· PH:

It is a step of the sourness or alkalinity of a solution numerically equal to 7 for impersonal solutions increasing with increasing alkalinity and diminishing with increasing sourness. The PH graduated table normally in usage scopes from 0 to 14. ( www.answers.com )

Categorization of Waste Water Treatment Methods

The effluent intervention is contaminations are removed by physical, chemical and besides biological methods. Sewage Treatment Plant single methods normally are classified as a physical unit operations, chemical unit operations and besides Biological unit operations and procedures. Although these operations and procedures occur in a assortment of combinations in Treatment Systems. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 )

4.2 Physical operations unit:

The Treatment methods in which the application of physical forces to rule are known as physical operation unit. Because most of these methods involved straight from the first observations of a nature, and they were the first to be used for effluent.treatment.

These are the Screening, Mixing, Flocculation, Flotation, deposit, Filtration, and Gas transportation are typical unit operations. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 ) .


The first off all unit operation entered in effluent intervention workss is testing.a screen is a device with gaps, by and large of uniform a size, that is utilizing to retain the coarse solids found in effluent.


The screening elements may dwell of parallel bars, wires or, grating, rods, mesh, or pierced home base, a screen composed of parallel bars or rods is called a saloon rack sometimes called a saloon screen ) .

The term screen is used for testing devices dwelling of perforated home bases cuneuss wire elements and wire fabric. The stuffs removed by these devices are known as showings.

Barroom Racks:

In Wastewater intervention, saloon racks are used to protect the Pumps pipelines valves and other gears from the damaged or choke offing by a shred and big objects.


Sewage intervention works is widely used to Barscreening, early screens were of the inclined disc or membranophone type, whose testing media consisted of bronze or Cu home bases with polished slots, and were installed in topographic point of deposit armored combat vehicles for primary intervention.since the early 1970s, there has been revival of involvement in the field of effluent intervention in the usage of screens of all types, the application scope from primary intervention to the remotion of the residuary suspended solids from biological intervention procedures. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 )


Mixing is an of import unit operation in many stages of effluent intervention including ( 1 ) the commixture of one substances wholly with another, ( 2 ) the commixture of liquid suspensions, ( 3 ) the blending of mixable liquids, ( 4 ) flocculation and ( 5 ) heat transportation.chemicals are besides assorted with sludge to better tidal lacrimation features. In anaerobiotic digestion, commixture is used accelerate the biological transition procedure and to heat the contents of the digester uniformly.

Description Apparatus:

Most mixing operations in effluent can be classified as uninterrupted rapid or uninterrupted. Continuous -rapid commixture is used most frequently where one substance is to be assorted with another. Continuous commixture is used where the contents of reactor or keeping armored combat vehicle or basin must be kept in suspension.

Energy dissipation commixture:

The power input per unit volume of liquid can be used as a unsmooth step of blending effectivity, based on the logical thinking that more input power creates greater turbulance, and greater turbulency leads to better commixture.

Deposit: :

It is one of the most widely used in waste H2O intervention, deposit is the separation from the H2O, by gravitative subsiding, of suspended solids that are heavier than H2O, it is one of the most widely used unit operations in effluent intervention.A Sedimentation basin may besides be referred to as a deposit armored combat vehicle, settling basin, or settling armored combat vehicle,

Deposit is used for grit remotion, peculiarly drifting affair remotion in the primary subsiding basin, biological float remotion in the activated sludge and settling basin and chemical flog remotion. Whenever ‘ the chemical curdling processes is used.

4.3 Chemical unit processes:

Sewage intervention works is widely used to chemical unit processes, This Treatment Methods in which the remotion or transition of the contaminations is brought approximately by the chemicals or by other chemical reactions are known as a chemical processes unit. There are three different types chemical procedures used in the effluent treatment.Precipitation, and disinfection and surface assimilation, which the procedure largely used in the effluent intervention. In the chemical precipitation, intervention is besides accomplished by bring forthing a chemical precipitate that will settle. In most instances the settled precipitate will incorporate the both components that may hold reacted with the adding to chemicals and the substance that were swept of effluent as the predicated settled in the H2O. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 )

4.4 Chemical curdling:

The colony of all right colloidal and suspended solids can be assisted by the usage of flocculation as but with dilute suspensions, such as lowland river Waterss, the chances for hits and agglomeration are limited. In such fortunes flocculation does non significantly better the subsiding features of the suspension. the add-on of a chemical coagulator, which precipitates woolly solids in the H2O, followed by flocculation and deposit, can supply a high grade of elucidation. the procedures of chemical curdling is therefore carried out in a sequence of operations, the first of which involves rapid to allow enmeshment of the colloidal solids in the quickly precipitating flock. ( THY Tebbutt, 1990 )

Following the initial phase precipitation phase, the suspension is passed to flocculation and deposit units, which may be separate or combined. the most popular coagulator for drinkable H2O intervention is aluminum sulfate, frequently referred to as alum. When it is added to H2O in little doses of around 20-50mg/l, a reaction takes topographic point with the natural alkalinity nowadays, and indissoluble aluminium hydrated oxide is formed. this responds good to controlled flocculation. The chemical reactions which occur are complex but may be simplified as

Al2 ( SO4 ) 3 +3Ca ( HCO3 ) 2 = 2Al ( OH ) 3 + 3CaSo4 +6CO2

When utilizing the commercial alum which has 16-18 molecules of H2O of crystallisation, and showing alkalinity in footings of Ca carbonate, each mg/l of alum reacts with 0.5mg/l of alkalinity. By utilizing a scope of coagulator does and PH values, it is possible to find the optimal conditions to accomplish the needed H2O quality. ( THY Tebbutt, 1990 )

Chemical precipitation:

In kernel, chemical precipitation depends upon the usage of an added reagent which combines with the dross to be removed to give an indissoluble merchandise which can so be removed by deposit, preceded by flocculation if necessary.

A ( dross ) + B ( reagent ) = C ( precipitate ) + D ( by merchandise )

It is clearly indispensable that any by-product of the reaction does non itself have unwanted belongingss in relation to the eventual usage of the H2O or effluent. It is besides of import to retrieve that chemical precipitation processes produce sludge ‘s incorporating the drosss and that the cost of managing and disposing of these sludge ‘s in a safe mode can be important. ( THY Tebbutt, 1990 )


Disinfection refers to the selective destroy of disease doing being.all the beings are non destroyed of during the procedure ; this differentiates disinfection from sterilisation, which is the devastation of all beings. In the field of waste H2O intervention, there are three classs of human enteral beings of the greatest effect in bring forthing disease are viruses, bacteriums, and amebic cysts.

Disinfection is widely used to wastewater sewerage intervention works ; there are good -established links between the taint of imbibing H2O with facial affair and the incidence of such H2O related diseases as cholera, enteric fever and many GI infections. Thus the remotion of the infective micro-organism from H2O supplies is a really valuable step for the betterment of public wellness. Disinfection means the devastation of infective micro-organisms and does non needfully intend that the H2O is unfertile, since a little figure of harmless micro-organisms are normally present in tap H2O and poses no jeopardy.

For most disinfection the rate of putting to death is given by

dN/dt = -KN

where thousand = rate invariable

N = figure of life micro-organisms

The rate changeless varies with the peculiar germicide, its concentration, the being being killed, PH, Temperature, and other environmental factors. ( THY Tebbutt, 1990 )

5. Biological unit processes:

Sewage Treatment works is widely used to Biological unit processes, this is processes is take the micro-organism of the H2O, In this Treatment methods in which the remotion of contaminations is conveying approximately by biological activity are known as a biological unit processes. Biological intervention is used primary to take the biodegradable organic substances affair ( means colloidal or dissolved ) in wastewater.Basically, these substances affair are converted into the gases that can be escaped to the ambiance and into the biological cell tissue unit that can be removed by settling. At the same clip this intervention is besides used to take the foods ( means N and phosphoric ) in effluent. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 )

5.1 Components of effluent Flows

The constituents of the effluent flows that make up the effluent flow from a community depend on the type of aggregation system used and may include the undermentioned:

There are four types of effluent flows available in the effluent intervention.

1. Domestic ( is besides called healthful ) effluent. This is sort of effluent discharged from abodes and from commercial, instutional, and house hold sewerage lavatory waste H2O, bath, sinks, and canteen effluent and similar installations.

2. Industrial effluent.this sort of effluent in which industrial wastes predominate.

3. Infiltration/inflow.water that enters the cloaca system through the indirect and direct agencies. The Infiltration is immaterial H2O enters that the cloaca system through the leaking articulations.

4. Storm H2O. Runoff ensuing from rainfall and snowmelt. This sort of constituents of effluent flows basically used in the sewerage intervention works.

5.2 Waste H2O intervention:

There are four different types of effluent processing in available in sewerage intervention works. Primary intervention referred to physical unit operations. Secondary intervention referred to chemical and Biological unit procedure, and besides Advanced or third referred to combinations of all four other processing.

A· Preliminary effluent intervention:

Preliminary effluent intervention is defined as the remotion of effluent components that may do to care of the operational jobs with the intervention of the operations. Examples of preliminary operations are testing and commuting for the remotion of dust ( J.Staudenmann, A. Schonborn, C. Etnier, 1996 ) .primary effluent intervention:

In primary effluent intervention, a part of the suspended solids and organic stuff is taking from the waste H2O. This remotion is normally accomplished with physical operations such as showing and deposit. The wastewater from primary intervention will normally incorporate considerable organic affair and will hold comparatively high BOD.treatment workss utilizing merely primary intervention will be phased out in the hereafter as execution of the EPA secondary intervention demands is completed. Rare cases ( for those communities holding a secondary intervention release ) will primary intervention be used as the exclusive method of intervention.the chief map of primary intervention will go on to be as a precursor to secondary intervention.

* Conventional secondary effluent intervention:

The secondary intervention is directed chiefly toward the remotion of bio degradable organics and suspended. Disinfection is included often in the definition of conventional secondary intervention is defined as the combination of procedures customarily used for the remotion of these components and includes biological intervention by activated sludge fixed movie reactors, or laguna systems and deposit.

A· Advanced effluent treatment/wastewater renewal:

Advanced effluent intervention is defined as the degree of intervention required beyond conventional secondary intervention to taking components of concern including toxic, foods, compounds, and larger sums of organic stuff and suspended solids.In add-on to the alimentary remotion procedures, unit operations or procedures often employed in advanced effluent intervention are chemical curdling, flocculation, and deposit followed by filtration and multi class filter and besides activated C filter. ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 ) .


6.2 Principle:

A Rotating biological contactor ( RBC ) is constructed of packages of plastic wadding attached radically to a shaft, organizing a cylinder of media.the shaft is placed contour bottomed armored combat vehicle so that the media are submerged about 40 per centum. the contactor surfaces are spaced so that during submerging in effluent can come in the nothingnesss in the wadding.when rotated out of the armored combat vehicle, the liquid trickles out of the nothingnesss in the wadding. when rotated out of the armored combat vehicle the liquid trickles out of the nothingnesss between surfaces and is replaced by air. A fixed movie biological growing, similar to that on a trickling filter wadding, adheres to the media surfaces. Alternating exposure to organics in the effluent and O in the air during rotary motion distributer. Excess the biomass gangrene from the media and is carried out in the procedures wastewater for gravitation separation.

A intervention system consists of primary deposit preceding and concluding deposit following the revolving biological contactors. Since the recirculation through RBC units is non usually practiced, merely sufficient underflow from the concluding clarifier is returned to let remotion of surplus of the biological solids in primary deposit and waste sludge similar to the character to the from dribbling filter works, in withdrawn from the primary clarifiers disposal of waste. In big type of workss, a common shaft is placed over a contoured armored combat vehicle with the effluent flow analogue to the shaft. A series of four phases are usually installed in the intervention of domestic effluent for BOD decrease. extra phases may be added to originate nitrification.Each phase acts as a wholly assorted chamber and the motion of the effluent through the series of armored combat vehicles simulates plug flow. Biological solids washed off of the media are transported hydraulicly under the baffles to be carried out with the effluent.RBC units are protected by installing either in a edifice with equal airing or under separate plastic screens lined with insularity.

The efficiency of BOD remotion of in the processing domestic effluent is based on empirical informations from runing RBC workss. the Mathematical equations besides have been developed, but their anticipation of the public presentation is non systematically dependable. the typically recommendations for secondary intervention of domestic effluent to bring forth an wastewater of less than 30 mg/l of BOD and besides 30mg/l of suspended solids. ( Mark J.Hammer Mark J.Hammer, Jr, 1996 )



1. Polymer sheet die 2m ten 2 thk – particular polymer from Germany

2. RBC Trough – poly propene /FRP

3. RBC Support – MS Resin Coated

4. Geared Motor ( 0.75HP ) – FLENDER

5. Input Coupling – Love Joy

6. Drive Support – Mild Steel

7. Bush – Nylon

8. Shaft – SS304


The undermentioned armored combat vehicles used in sewerage intervention works based Rotating Biological contactor Processes.

1. Bar screen

2. Collection Tank

3. Pit 1,2,3

4. Flow splitter

5. Sludge drying bed

6. Semi Treated H2O armored combat vehicle

7. Multi grade sand filter

8. Activated C filter

9. Treated H2O armored combat vehicle


The undermentioned equipments used in sewerage intervention works based Rotating Biological contactor processes.


RBC 0.75 horsepower 1

Submersible Pump 1 Hp 2

Submersible Pump ( Lamella ) 1 Hp 1

Filter feed submergible pump 3 Hp 2



Natural sewerage features:

Domestic waste H2O:

The volume of a effluent from a community varies from 50 to 250 gal capital per twenty-four hours depending on the cloaca system uses. A common values for domestic effluent flow is 120 gpcd means 450 litre individual per twenty-four hours usage, which assumes that the residential waste H2O have modern H2O utilizing contraptions, such as automatic rinsing machines. the organic substances matter contributed per individual per twenty-four hours in domestic effluent is about 0.24 pound to 110gram of suspended solids and 0.20lb and 90 gm of BOD in communities where a significant part of the family kitchen wastes is designed is discharged to the cloaca system through refuse bombers. In choice of informations for design, the measure of and organic strength of effluent should be based on existent measurings taken through the twelvemonth to account for fluctuations ensuing from seasonal climatic alterations and other factors. the mean values during the peak month may be used for design, excepting un usual infiltration and influx, the mean day-to-day healthful effluent flow during the maximal month of the twelvemonth is normally 20 to 30 per centum greater than the mean one-year day-to-day flow, excepting seasonal industrial wastes, the mean day-to-day BOD burden from healthful effluent during the maximal month is greater than the one-year norm by 30 per centum or more in little workss less than 0.5 mgd and less than 20 per centum in big workss greater than 50 mgd. ( Mark J.Hammer Mark J.Hammer, Jr, 1996 ) .

Municipal effluent:

In municipal effluent flow in healthful cloacas is a composite of domestic and industrial effluents, there are two flows infiltration and influx, and intercepted flow from combined cloacas. Collector cloacas must hold hydraulic capacities to manage maximal hourly flow including domestic and infiltration, the new cloaca systems are normally designed on the rudimentss of an mean day-to-day per capital flow of 100 gal of 400 liters. However, pipes must be sized to transport peak flows that are many times assumed to be 400 gpcd and 1500 litre individual used. waste strength is greatest during the working day when family and industrial activities are lending a larger sum of organic affair, and it is reduced during the dark when come ining flow is less contaminated and slow speeds in pipes permit the subsiding solids. if both flow and BOD concentration fluctuation are known, as the cognition of inflowing hydraulic and BOD burdens are indispensable in measuring the operation of a intervention works. ( Mark J.Hammer Mark J.Hammer, Jr, 1996 ) .

Graph: Variation in concentration of BOD in the waste H2O and ensuing BOD lading form. ( Mark J.Hammer Mark J.Hammer, Jr, 1996 )

Graph: Waste H2O flow and strength fluctuations for typical medium sized metropolis.

( Mark J.Hammer Mark J.Hammer, Jr, 1996 ) .


From the flow divider the sewerage will come in the RBC. In the RBC the BOD / COD digestion will take topographic point. The discs which will hold the all right surface will let the bacteriums to turn in its surface. The surface country will make up one’s mind the Colonization of bacterial mass.

Revolving Biological Contractors ( RBCs )

The RBC procedure consists of a series of closely spaced phonograph record ( 2m ) in diameter ) mounted on a horizontal shaft and rotated, while about one – half of their surface country is immersed in effluent. The phonograph record are typically constructed of lightweight plastic. The velocity of rotary motion of the phonograph record is adjustable.

When the procedure is placed on operation, the bugs in the effluent Begin to adhere to the revolving surface and turn at that place until the full surface country of the phonograph record is covered with a 1- to 3 millimeters bed of biological sludge. As the phonograph record rotate, they carry a movie of effluent into the air ; this effluent trickles down the surface the phonograph record, absorbing O. As the phonograph record finish their rotary motion, the movie of H2O mixes with the reservoir of effluent, adding to the O in the reservoir and blending the treated and partly treated effluent. As the affiliated bug base on balls through the reservoir, they absorb other organics for dislocation. The extra growing of bugs is sheared from the phonograph record as they move through the reservoir. These dislodged beings are kept in suspension by the traveling phonograph record. Therefore, the phonograph record function several intent: ( George Tchobanoglous and Franklin L. Burton, 1991 )

1. They provide media for the buildup of affiliated growing.

2. They bring the growing into contract with the effluent.

3. They aerate the effluent and the suspended microbic growing in the reservoir.

4. The affiliated growings are similar in construct to a trickling filter, except the bugs are passed through the effluent instead than effluent passing over the bugs. Some of the advantages of both the trickling filter and activated sludge procedures are realized.

As the treated effluent flows from the reservoir below the phonograph record, it carries the suspended growings out to a downstream subsiding basin for remotion. The procedure can accomplish secondary wastewater or better. By puting several sets of phonograph record in series, it is possible to accomplish even higher grades of intervention, including biological conversation of ammonium hydroxide to nitrates ( George Tchobanoglous, FranKlin L.Burton, 1991,1979,1972 ) .

We have provided in entire 80 nos of discs. The discs are 2mtr diameter 2 millimeter midst.

The entire surface Area: 502 M2

The disc are revolving in a slow revolutions per minute thereby let the settlement of bacteriums to expose in the ambiance and sewerage H2O alternately. This will let plenty O for the mass to turn and besides will digest the BOD / COD degrees in the sewerage H2O. This ‘Fixed movie ‘ growing in the disc, unlike conventional STP will be denser and due to that the infinite will be little.

RBC Design Calculation of H2O ingestion:

Entire Raw H2O BOD5 = 250 milligram / ltr x 50 KLD

= 12500 g / twenty-four hours.

Primary Treatment = 15 % Decrease

i.e 2437g/day decrease in primary and available BOD is 13813 g/day.

Available BOD = 10625 g / twenty-four hours.

BOD burden: 30 g/m2/day

i.e since being a attached growing system the criterion for BOD digestion in the disc is 30 gram per twenty-four hours per M2 of available surface country of the disc.

Disk Surface Required = BOD5 g / twenty-four hours: 30 g / ( M2 x vitamin D )

= 10625 / 30

Surface Area Required = 354 M2

Diameter of one disc vitamin D: 2.0

Area of one disc: 2 ten P ( 2.0 ) 2: 6.28 M2. ( Taking consideration of both side of the disc

No of disc selected: 80 any

Entire Surface Available: 502 M2.

Our demand of 354 M2 of surface country meets out with available surface country of 502 M2, which 40 % more than the demand.

Surface country available is much more than required. This will take attention of a maximal flow of 70KLD where as the existent flow will be merely 17 KLD works.

Retention Time:

Length of trough ( each chamber ) : 1990 millimeter

Diameter of trough: 2200 millimeter

30 % onlyfilled with H2O

Volume Pd2 x L x 0.3= 2.27 M3.

Specific Retention clip required: 0.33 hour.

Specific keeping clip for the trough in the RBC is 0.33 hour for the digestion of 30 g/m2/day BOD5 in a unvarying burden.

Premise: Film growing around 1.5 – 2 millimeter thickness

Retention clip available

Flow: 50 KLD

Flow in m3/hr: 2 M3 / hour

Retention clip = Volume of Trough

Flow in m3 / hour = 2.27 M3

2 = 1.135 hours

The keeping clip really required is 0.33 hour where as available keeping clip for the unvarying flow of 2 m3/hr is 1.135 hours.

Lamella Centrifuge:

After the RBC the sewerage H2O will go through through Lamella centrifuge where the suspended affair will settle down. The settled biomass at the Lamella underflow will be sent to the sludge drying bed sporadically. There is no demand for recycling of the sludge as like in the conventional aeration system. The flood from the Lamella clarifier will be the semi treated clarified H2O.

Retention clip required: 0.4 – 0.6 M3 / hour /m2

Size of LMS = 1.275 x 1.42 ten 2.11 ( Total tallness ) with 673 millimeters conelike tallness

Volume = 3.2 M3

Retention clip available = — — — — = 1.6 hour

2 M3 / hour

Whereas the needed degrees are 0.4 – 0.6 m / hour

Treated outflowing features:

Advantages of RBC:

A· RBC s are capable of managing a broad scope of flows.

A· Operating costs are low because small accomplishment is required.

A· Short keeping clip.

A· Low power required.

A· Low Sludge production.

A· Excellent procedure control.


A· Shaft bearings and mechanical thrust units require frequent care.



A pump is a device of indispensable used to travel fluids, such as gases liquids. A Pump displaces a volume by physically or automatically action and operation. one common map of pump is the create a force per unit area. Pumps entirely do non make a force per unit area, merely displace fluid, and doing a flow.the pumps opposition to flux causes force per unit area. it is a pumps falling into five major groups, in which a supplanting, speed, direct lift, gravitation and perkiness pumps. these types of pumps describe the method for traveling fluid.

Background Information:

Engineers foremost preferred pumps to present a liquid or gas to specific topographic point at a indispensable rate. Liquids and gases are known as a fluids. A pump is usually used to alter the lift, speed or force per unit area of a fluid. In of course, a fluid will flux of course from the high topographic point to a low topographic point like a H2O autumn or from the high force per unit area. to a low force per unit area from the interior a balloon to the outside air. its speed is many times map of geometry and the conditions around it. when a fluid is required to from a beginning like a pool, at a higher force per unit area than a beginning, or at a higher rate and expert applied scientists will merely see a pump to carry through the undertaking.

This lessons will be broken into the five basic subdivisions and basic footings besides included, fluid statics and flow rates and the Bernouli equation, and a signifier of the energy equation for pumps.As it progresses, we will travel from the basic definitions and footings to happen out the power of an idealised pump. Some of the footings we need to get down with are gravitation or the gravitative invariable, denseness and besides force per unit area. ( mechanicalpumps.com ) .

11. Submersible Pump:

11.1 Description:

The sewerage intervention works is largely used to submergible pump because this type of pump is really high efficiency at same clip efficient of the procedures.

The sewerage submergible pump is suited for outflowing tranfer in domestic waste H2O intervention works, and besides industrial applications, where suspended solids need to be reduced in size and pumped over the short to medium distance, this pump shaft is 304 chromium steel steel fitted with a dual mechanical seal in an oil chamber.this pump with 10 metres of heavy responsibility processes.submersible pump costructed in dramatis personae Fe and 304 chromium steel steel. ( hypertext transfer protocol: //www.southernpumpservices.co.uk/submersable_water_pump_history.htm

Submersible pump is largely used in sewerage intervention works which is used inside the H2O, this type of sewerage pumps with power up to 70kw ( 95 HP ) .this type of pump mounted in dramatis personae Fe and unstained steel building. The full scope includes individual and multi channel and besides self cleaning for pull offing solids with fibres and mounted in whirl impeller, crunching version besides available in submergible pump. There are four theoretical account of submergible pumps used to DLS, DLV, DLC, DLG Sewage intervention works.

10.2 History of Submersible pump:

Submersible pumps originally used in Europe, submersiblewastewater, foulwater, And Sewage pumps foremost were seen in the United States in the mid 1950s.submersible pumps are the dominant characteristic in the pumping station market. A submergible pump includes non merely the pump motor unit, but sophisticated to both electrical and mechanical controls, shrieking and wet well with entree frame and screen, tooThe submergible solids managing sewerage pump operates under H2O and is flood cogent evidence. It is fundamentally designed for individual or double, wet ( hypertext transfer protocol: //www.southernpumpservices.co.uk/submersable_water_pump_history.htm

The pump is efficient, and really quiet in operation, safe to put in and execute long and dependability, the submergible effluent pump is used primary for wet cavity sewerage pump station and for industrial sump or processes outflowing applications, a common used for little pumps is to travel wastewater from the armored combat vehicle.

Large and little units are used in a different of ways in the place, farm hotel and school, Marine, commercial edifice, industrial works and municipal or domestic sewerage and storm H2O pump processes or systems. Submersible pumps have been proven over the last half of a century, and confuting those who originally questioned how electric motor powered pump was could run under H2O. These pumps originally developed in Europe states, and at same clip now are used daily throughout the universe to pump clear H2O, natural H2O and waste H2O.

The submergible pump used to wastewater, disgusting H2O, and surface H2O and sewerage pump became popular in the early sixtiess, when a usher rail system was developed to raise the pump out of the cavity for the fix. This ended the dirty and sometimes hard undertaking of directing people into the sewerage or wet spot. Growth of the submergible for effluent pumping since has been alteration and betterment, as an increasing figure of specifies and users learned of its advantages. two types of categories of submergible exist, the smaller units normally called sewerage ousters, are used in house and light commercial applications, they will usually manage up to 55mm spherical solids and scopes from.75kilowatt to 2.2kilowatt.

Larger submergible pump grip 65mm and larger solids and have a lower limit of 80mm discharge. They are used in municipal effluent and industrial applications for pumping sewerage and all types of industrial effluent.

Technical Specification:

Model = DLS, DLV, DLC, DLG

Delivery = up to 1.500,00 m3/hour

Head = up to 82, 0 m

Power supply = both 1 and 3 50HZ.

Power = Ranges from 0.95kw up to 70,00kw

Temperature of wired liquid = 40 degree Celsius.


1. Residential waste H2O

2. Commercial waste H2O

3. Light industry waste H2O

4. Municipality waste H2O ( Refhttp: //www.lowara.co.uk/products/product. )

Submersible pump characteristics:

The submergible waste H2O pumps are perpendicular, direct coupled, excess heavy responsibility units, which have operate under the H2O and have solids managing, and not geta capableness. while individual pumps many times are installed, most application are require two pumps this is called semidetached house to guarantee two and to guarantee continued procedures of operation, if one pump fails to minimise wear on one pump and equalise it between two and to supply excess capacity in times of extraordinary tonss.

A submergible pumping system consists of the motor pump unit together with automatic electrical controls. Controls can be simple or complex, depending on the application. The latter may dwell of an full mill packaged station enclosed in a steel or armored combat vehicle of fibreglass armored combat vehicle and ready for the installing and pipe electrical hook up. Submersible are being specified progressively in applications where ego priming, dry cavity, consecutive centrifugal, perpendicular extended shaft and pneumatic rejecter pumps one time dominated.

Submersible pumps is depending on the impeller design, a 100mm discharge pump usually will manage spherical solids of 80mm.each industries literature specifies the upper limit of solids size, which can be handled by a peculiar pump. Normal discharge sizes for larger submersible is ranges from 80mm to 600mm and larger. This type of pump selected should be sized to the application. Submersible pump motors besides can be sized to the application.

The usually submergible pumps are available in 950, 1450 and 2900 rotary motion per minute, on 50 rhythm power.kilo W evaluations ranges up to 200kilowatt or larger. The variable velocity unit besides is available with the usage of variable frequence and electromotive force power supplies. Again depending on the application of the motors runing on, 230 Vs and 415 Vs are available and may be individual or three stages. Single phase units normally are limited to 2.2 kilowatt.thus, submergible can be tailored to occupation necessities. Like any pumps, particularly submersibles besides can be tailored to the capacity needed of the peculiar installing. A specified can be ask for a high dynamic caput, or can accept a lower caput and obtain a higher L/S or can acquire both the higher caput and a higher flow rate by increasing the kW evaluation. Typically heads scopes from 2.5 metres to 95 metres. Flow rates ranges from 21/s to be 2001/s, and larger submergible pumps produce 6000 1/s 0r more. The pump motor unit can be tailored to installing demands. Many larger submergible pumps can be used in concurrence with a variable velocity thrust to farther suit the public presentation to theapplication.. ( hypertext transfer protocol: //www.southernpumpservices.co.uk/submersable_water_pump_history.htm

Pumping system constituents:

To plan a cost effectual pumping system it is non sufficient to merely see merely the basic caput and flow needed of the pump, as a figure of other factors need to be taken into consideration, Source of wastewater within the recess gravitation system, and the nature of the liquid to be handled. The pump hydraulic design and the best suitable stuffs of building. Pump size and effectual volume of the pump sump and consideration of liquid deepness and its consequence on pump public presentation. The internal defining of the pump sump, for moisture well applications and to forestall deposit effluent processes. The right spacing and placement of pumps within the moisture well applications.

The design of the pump recess pipe work for dry well applications. The size and design of the pump station discharge pipe work under all operating conditions. The pumping system of constituents sizing and design of the pump chief consideration. The effects of variable liquid degrees at the concluding discharge of point on the pump public presentation curve. Beginning of power supply, and current restrictions and motor get downing method.

12.Power Consumption analysis of sewerage intervention works:


Model = DOC

Delivery = up to 14 m3/hour

Head = up to 11,0 m

Power supply = both 1 and 3 50HZ.

Power = Ranges from 0.25kw up to 0.55kw

( www.lawara.co.uk )


Pump entire caput = 11 metre

To pump entire caput converted into pess 1 metre = 3.280 pess

So submergible pump entire caput 11 metre = 36.08 pess ( calculateme.com )

Submersible pump bringing Q = 14m3/hour

Submersible pump bringing convert into gallons per minute,1 m3/hour = 4.4028gallons/min.

Entire submergible pump bringing Q = 14 M3 /hour = 61.640 gallons/min ( unitconversion.org )

Revolving Biological contactor based sewerage intervention works H2O influent is 60 kg litre per twenty-four hours, Assumption of H2O influent is =60 KLD

To kilo liter per twenty-four hours convert into gallons per hr

Entire bringing of influent Q = 60 549.92 gallons per hr

To gallons per hr convert into gallons per minute Q = 549.92 gallons/hour

Q = 9.165 gpm

To cipher the pump H2O Equus caballus power,

Water Equus caballus power expression ( Whp ) is =

The undermentioned information is given bringing Q = 9.165 gpm

Entire caput = 36.08feet

Water Equus caballus power expression ( Whp ) is, =

Pump H2O Equus caballus power is ( Whp ) = 0.08 Hp.

Then to cipher the pump Brake Horse power,

Submersible pump power ranges from 0.25kw to 0.55 kilowatts

Actually power required to run the H2O is =0.55kw

To happen out pump Brake Horse Power, ( BHP ) =

Submersible pump efficiency is assumed at changeless =50 to 85 % efficiency,

To Brake Horse power ( BHP ) = ( take mean efficiency of the motor )

Pump Brake Horse power ( Bhp ) = 0.12 horsepower.

Then to happen out the pump motor Equus caballus power ( Mhp ) =

BHP = 0.12 horsepower,

Motor efficiency =85 % or 0.85

Pump Motor Equus caballus power ( Mhp ) =

Motor Equus caballus power ( Mhp ) is = 0.145 Hp

Kilowatts of energy consumed per twenty-four hours

How much sum of energy consumed in submergible pump,

Kilowatts hours twenty-four hours formula = horsepower x 0.746 kw/hp x 12 hr/day

Actual working of pump 12 hrs/day = 0.24 Wattss x 12 hrs/day

Pump energy consumed per twenty-four hours = 2.88 kilowatts hour/day

Actual pump power ranges from 0.25kw to 0.55kw

Covert into Watts from the power, existent power used 0.25 ten 2 = 0.50 Watts.

Power required to run the system portion = 2.88 kilowatt hour/day

Actual power used = 0.50 Wattss X 12 hour/day

= 6 kwh/day.

To finout power loss = power required to run the system – Actual power used in the works = 6 kwh/day – 2.88 kwh/day

= 3.12 kwh/day

Power loss = 0.26 kW

14. Consequences

15. Discussion:

The major drawback of RBC is the dislocation of shaft bearing and mechanical thrust units. From the computations of submergible pump, 0.25 KW to 0.55 KW scope of pump power, 0.20 Watts of power is lost. When compared to other pumps such as centrifugal and ego priming pumps, there is minimal power loss in submergible pumps because the location of the pump. ( Submerged in H2O ) .

16. Decision:

The sewerage intervention works has been successfully analyzed. The 2D analysis of Revolving Biological Contactor has been done. The analysis of H2O ingestion and power ingestion has been done.

17. Bibliography

* answers.com. ( n.d. ) . answers.com. Retrieved from hypertext transfer protocol: //www.answers.com

* calculateme.com. ( n.d. ) . www.calculateme.com. Retrieved from hypertext transfer protocol: //www.calculateme.com/Length/Meters/ToFeet.htm

* George Tchobanoglous and Franklin L. Burton. ( 1991 ) . Wastewater Engineering ( intervention, disposal, and reuse ) . Metcalf and Eddy, INC.

* George Tchobanoglous, FranKlin L.Burton. ( 1991,1979,1972 ) . WasteWater Engineering Treatment Disposal Resue. In WasteWater Engineering Treatment Disposal Resue. ( Vol. III ) . United states: Metcalf & A ; Eddy.

* J.Staudenmann, A. Schonborn, C. Etnier. ( 1996 ) . Recycling the Resource, Ecological Engineering for Wastewater reatment ( Vols. 5-6 ) . Transtec Publication, UK.

* Mark J.Hammer Mark J.Hammer, Jr. ( 1996 ) . H2O and effluent engineering. In H2O and effluent engineering. prentice-hall, Iraqi National Congress.

* mechanicalpumps.com. ( n.d. ) . www.mechanicalpumps.com. Retrieved from hypertext transfer protocol: //www.mechanicalpumps.com

* Norcross.K.L. ( 1992 ) . Sequencing Batch Reactors-An Overview, Water Science and Technology.

* THY Tebbutt. BASIC H2O and effluent intervention.

* THY Tebbutt. ( 1990 ) . Basic H2O and effluent intervention. Butterworth & A ; carbon monoxide.

* unitconversion.org. ( n.d. ) . unitconversion.org. Retrieved from hypertext transfer protocol: //www.unitconversion.org/flow/cubic-meters-per-hour-to-gallons-us — per-minute-conversion.html


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