approx waste watertreatment fac power requirements revd

8/9/2019 Approx Waste WaterTreatment Fac Power Requirements RevD

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ENVIRONMENT, ENERGY ANDTECHNOLOGY MANAGEMENT

Paper onSequencing Ba c! Reac or Po"er Sa#ing$

B%&

Da#i' T( Ve)a$co, REEEngineering Prac ioner

Dr( *)oran e A( Magna%eEn#iron+en a) A'#i$or

Marc! -., -/0.


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Sequencing Batch Reactor Power SavingsDavid T. Velasco, Registered Electrical Engineer, Active Member, IIEE-NCR

ABSTRACTEngineers and designers need to reduce man-hour cost in order to provide proper engineering and

competitive service. uic! and relia"le estimates o# $$T% energ& demand "ased on current operatingparameters and standard engineering methods can reduce design man-hour cost. %or this reason, estimates"ased on current operating parameters and standard engineering methods is a proper engineering practice tochec! the via"ilit& o# a proposed scheme or to appro'imate equipment si(e and estimate power requirements.

The )eration process o# a wastewater treatment #acilit&, $$T%, consumes *+ o# the power #or thewhole process. Suppl&ing power #rom renewa"le energ& source to the aeration equipment can reduce theoperation cost "& a ver& signi#icant amount. This paper shall investigate the potential "ene#its o# cogenerationscheme "& utili(ing "iomass and wind energ& conversion s&stem as well as esta"lish a relia"le power estimatemethod #or $$T%.

1. INTRODUCTIONn alleviating the pro"lem o# natural water "od&

contamination, the Philipine law under D) -/0mandates that all used water shall "e treated"e#ore released in the pu"lic sewer. The mostrelia"le water treatment is the Sequencing BatchReactor 1)ctivated Sludge 2SBR3 process, since itrequires less in#rastructure #ootprint and utili(esorganic mechnism to "rea!down the watercontaminants. The process is costl& in terms o#electric power usage. t is shown that #rom amongthe di##erent stages in the SBR, the 4aeration stage5consumes large amount o# power. There are wa&sto gain su"stantial savings when operating theSBR. )side #rom the use o# computeri(ed processcontrols, the solid waste #rom the SBR can "eutili(ed #or on-site power generation which can "echeaper. The alternative power source can providesu"stantial savings #rom the lower power cost "&6/ . This paper descri"es and presents themethod used.

2. CMAS

)ctivated Sludge Reactor-7omplete mi'.n#luent wastewater decomposes in solids thatsettles at the "ottom as sludge. Sludge particlesproduced "& the growth o# organisms 2including(oogleal "acteria3 in tan!s in the presence o#dissolved o'&gen. The term 4activated5 comes #romthe #act that the solid particles are teeming with#ungi, "acteria, and proto(oa. )ctivated sludge isdi##erent #rom primar& sludge in that the sludgeparticles contain man& living organisms which can#eed on the incoming wastewater. n this "iologicalaero"ic reactor, it is assumed that complete mi'ingoccurs instantaneousl& and uni#orml& throughoutthe reactor as #luid particles enter the reactor. %luidparticles leave the reactor in proportion to theirstatistical population. The actual time required toachieved completel& mi'ed conditions will dependon the geometr& and power input.

8.9 Reaction

n#luent wastewater enters at #lowrate , is de#inedas a su"strate with its component 4constituents5-contaminant su"stances, 2So : B D0 3, 7 D,;SS in TSS value, in tan! o# volumeV, is composed o# "acteria 2as "iomass3 and B D.

The "acteria consumes B D and ;


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%SS : #i'ed suspended solidsTSS :densit& o# TSSvss : densit& o# VSS

The =>VSS is directl& a##ected "& "iological actionsuch that processes are quanti#ied in this termsincluding car"onaceous o'idation and nitri#ication.The #raction o# TSS that is VSS is usuall& +.H to+.I, a t&pical value is +. , J9K

$ith a given volume V, mass product P'vss isrelated to SRT "&L

P'vss GSRT : vss G V , (7-54)P'vss : P'"io F G2n"VSS3 , (8-15)

8./ B D Demand,


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"ut parameters are selected onl& to provide a quic!energ& demand estimate. Re#er to %ig./.9 and /.8

/.9 %@=%ood to =icroorganism ratio #or suspended growth-

activated sludge process ranges #rom +.+6 to +.0per SRT?8+-/+ d SRT L +.+6g to +.9g0-H d SRT L +./g to +.0g

%@= : GSo @ VG vss : So@, is usuall& ta!en#rom 9++ to 90+ mg@> , with 90+mg@> as t&picalvalue.

SV : settled vol o# sludge, m>@>3G29+ /mg@g3 @

2suspended solids, mg@> in /+minutes3

s : 29+++mg@g3G29+++m>@>3 @ SV mg@>

Vt G TSS : Vs G s

$hereL

s : settled volume a#ter decant, g@m /

TSS : =>SS concentration 2densit&3 at #ull

volume, g@m /

4. AERATIONThe process o# adding air to water as a method toadd o'&gen into the mi'ture 2and to !eep particles

in suspension3. Di##used )ir t&pe consist o#wastewater su"merged coarse or #ine "u""leceramic di##user, header pipes air mains ducts and"lowers through which the air passes.

6.9 ) R'&gen must "e provided in "iological treatment

s&stems to satis#& several t&pes o# demands. Theseare re#erred to as actual o'&gen requirements or

) R. ) R is alwa&s e'pressed as 4#ieldconditions5. The amount o# B D and ammonia-nitrogen to "e removed is equivalent to the mass o# "acteria and their o'&gen inta!e to survive andmeta"oli(ed the B D and ;


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ammonia. 'idi(ing 80 mg@l o# ammonia isequivalent to an additional 990 mg@l o# B Dloading. Be aware that even i# a plant is notspeci#icall& designed to nitri#&, that under #avora"leloading, temperature and SRT conditions,nitri#ication can and will occur. This ma& e'ert alarge unanticipated o'&gen demandon the s&stem and ma& result in process #ailure.

6.8 S R

To determine the amount o# process air required tosatis#& the "iological treatment o'&gen demands.

) R shall "e converted to standard o'&genrequirements 2S R3 to properl& appl& the aerationequipment "ecause aeration equipmentmanu#acturers can provide in#ormation to engineersand designers on the o'&gen trans#er capa"ilit& o#particular equipment and con#igurations when theequipment is aerating clear tap water. 2S R o#equipment3. >a"orator& tests, when corrected #ortemperature and elevation to standard conditions,"ecome the "asis #or determining the equipmentMsstandard o'&gen requirement or S R.

Equipment manu#acturers cannot guarantee theo'&gen trans#er capa"ilit& o# aeration equipment inwastewater. Each wastewater treatment plant hasits own unique #ield conditions and waste t&pe thatpreclude this t&pe o# guarantee.

The general accepted #ormula to convert ) R toS R isL

S R:) R @ J2BG 7sthG+.0G22Pd@Patm3 @ 7s8+3G9.+86 2T-8+3GaG% K

$hereL ) R : actual o'&gen requirement 2#ield conditions3S R : standard o'&gen requirement 2standard

conditions3 Standard conditions are (ero elevation28I.I8 "arometric pressure3, 8+ 7 and (ero D2dissolved o'&gen in liquid3.Beta, B : sur#ace tension correction 2Saturation3%actor, +.I0 1 +.I .7sth : o'&gen saturation concentration incleanwater, mg@>.Pd : pressure at depth o# air release,!PaPatm< : atmospheric pressure at mean < level

t : percent o'&gen in tan!, 9 to 8+$or!ing dissolved o'&gen concentration inwastewater

T : perating temperature o# wastewater 7s8+ : Sur#ace D saturation concentration at 8+7 and standard conditions #or the particular aeration equipment at the design su"mergence

7> : operating o'&gen concentration, mg@> atdesign temperature T and 9atm #or the particular aeration equipment at the design su"mergence

% : #ouling #actor, +.*0 to +.I

)lpha , a: o'&gen correction #actor #or o'&gen #orwaste.a : +.6 to +. #or di##used aerators, +.* t&pical,J8Ka : +.* to 9.8 #or mechanical equipment

7 ==E;T)RN )lpha is the ratio o# the mass trans#er coe##icient inwastewater to the mass trans#er coe##icient in tapwater. )lpha is the most varia"le #actor in the#ormula and the most di##icult to accuratel& test.The #ollowing generali(ations can "e made a"out#actors that a##ect alpha values.

U B D loading per unit volume U Process used, i.e. a process that nitri#ies t&picall&less higher alpha values than a process that doesnot nitri#&

U T&pe o# aeration device, i.e. coarse "u""le or #ine"u""le

U =i'ing regime, i.e. plug #low or complete mi' U >ocation within aeration tan!, in#luent end vs.e##luentend

U T&pe o# waste U Su"mergence o# aeration device

The #ollowing shall "e used #or SBR

appro'imation , J8K

9. The t&pical ) R@S R ratio #or a 7 )RSEB BB>E aeration s&stem is +.0+.

S R : ) R @ +.0

8. The t&pical ) R@S R ratio #or a % ;EB BB>E aeration s&stem is +.//.

S R : ) R @ +.// , 26.8-93

6./ )ir %low rate, cmpm )ir %lowrate : S R @ 2 TE G *+min@hG !g

8@m / air3

$here L

S R :Standard '&gen requirement, !g@h

TE : '&gen trans#er e##icienc&, 7eramic disc

at 6.0m su"mergence : /0

29.9 68G +.8/9 3 : +.//Og 8 @ m / air, 80 7,

6.6 B> $ER P $ER RE RE=E;T

Pw" : J2P8@P93 +.8 / -- 9KG w

G*+G ./96G28H/.90FT93 @ 2 8I.H G n G e3

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$hereL

Pw" : power required o# each "lower, !$

w : weight o# #low o# air, !g@min

./96 : air gas constant, R, !W@! mol

T9 : inlet temperature, deg 7

P9 : a"s inlet pressure, atm

P8 : a"s outlet 2discharge3 pressure, atm

n : +.8 / #or air

8I.H : constant

e : "lowerCcompressor e##icienc&, +.H to +.I

Pressure lossesL the pneumatic #riction loss

#rom pipe and #ittings plus the head loss #or

su"merged di##user at water depth accounts #orthe power loss o# aerator "lower.

7riteria #or marginal designL Power >oss : 9+ o#Power output that is re#lected on the "lowerdischarge pressure.

5. ANAEROBIC DIGESTER

0.9 =ethane production )n anaero"ic digester can "e utili(ed to recover theenerg& content o# wasted sludge #or an SBRwastewater treatment. n the digester its own SRTstarts as some species o# "acterial anaero"icheterotrophic organisms, initiates the digestion "&lique#actionCh&drol&sis o# the input materials suchas? insolu"le organic pol&mers, such ascar"oh&drates "ro!en down to solu"le derivativesand proteins, lipids, pol&saccharides nucleic acidscontained in the sludge "iomass? that "ecomeavaila"le #ood #or other "acteria. %ermentationprocess then precedes as )cidogenic "acteriaconvert the sugars and amino acids into car"ondio'ide, h&drogen, ammonia, and organic acidswhile )cetogenesis "acteria convert these resultingorganic acids into acetic acid, along with additionalammonia, h&drogen, and car"on dio'ide. The #inalprocess o# =ethanogenesis "egins asmethanogens convert these products to methaneand car"on dio'ide.

)#ter the SBR SRT period, the wasted sludge"iomass, P'"io represented in VSS 7 D terms "&#actor o# 9.68 g7 D@ g Biomass VSS, shall "e thein#luent characteristics o# the anaero"ic growthsuspension process o# the digester.

)ccording to sectionH-98 J9K, the required mass"alance is per#ormed to quanti#& the process as#ollows?

)ccumulation : 7 Di 17 De 1 7 Dnc 1 7 Dm

)ssuming no accumulation remains in tan! a#terprocessL+ : 7 Di 17 De 1 7 Dnc 1 7 Dm

7 Dm : 7 Di 17 De 1 7 Dnc$here?7 Dm : n#luent 7 D, 7 Di , converted tomethane7 De : portion o# in#luent 7 D in e##luent, ta!enas sample &ield which is 0 o# 7 Di

7 Dnc : n#luent 7 D converted to new celltissue, ta!en as sample &ield which is I0 o# 7 Diwith a #actor o# +.6 2gVSS@g7 D3 methanogenesissolids &ield parameter to produce methane.

Thus the #orecasted methane production shall "eas #ollowsL7 Di : 9.68 G P'"io , 2!g 7 D@ d3

7 Dm : 7 Di 1 +.0G7 Di 1 +.I0G7 Di G+.+6 22!g 7 D@ d3

The volume o# methane at 80 7 is calculated as+./I m / 7< 6 @ !g 7 D and with heating value,


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The e'tracted power #rom the Sequencing BatchReactor wasted sludge reprocessing thru an

)naero"ic Digester can meet the power demand #or the aeration process and thus decrease the energ&cost there"& assuring the via"ilit& o# a wastewatertreatment #acilit&. %urther stud& can "e per#ormedto determine the actual &ield contri"ution o# outsidesolid waste to augment the SBR output.

t is recommended that an SBR with )naero"icDigester wastewater treatment #acilit& should "einstalled to augment e'isting septic tan! s&stemsand a"ate #urther water pollution o# natural waters.

9. REFERENCES

J9K $astewater Engineering 1Treatment and Reuse,=etcal# A Edd& 6 th Ed.

J8K S-EP) 4Summar& Report %ine Pore 2%ine

Bu""le3 )eration S&stems5, EP)@*80@ -

0@+9+,9I 0.

J/K


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APPENDI/


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APPENDI/ 2


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Table 2A - EFFLUENT STANDARDS: Conventional and Other Pollutants in Prote ted !atersCate"or# $ and $$ and in $nland !aters Class C (a)

Para%eter Unit

Prote ted !aters $nland !aters

Cate"or# $ Cate"or# $$

&Class AA ' SA( &Class A) * ' S*( Class C

OE$ NP$ OE$ NP$ OE$ NP$

Color PCU (b) (b) 150 100 200c 150c

Temperature(max rise in deg. Celsius inRB )

!C rise (b) (b) " " " "

p# (range) (b) (b) $.0%&.0 $.0%&.0 $.0%&.0 $.5%&.0

C' mg * (b) (b) 100 $0 150 100

+ettleable +olids (1%,our) mg * (b) (b) 0." 0." 0.5 0.5

5% a- 20 oC B' mg * (b) (b) 50 "0 0 50

Total +uspended +olids mg * (b) (b) /0 50 &0 /0

Total issol ed +olids mg * (b) (b) 1 200 1 000 % %

+ur actants (3B4+) mg * (b) (b) 5.0 2.0 /.0 5.0

'il rease (Petroleum 6t,er6xtract)

mg * (b) (b) 5.0 5.0 10.0 5.0

P,enolic +ubstances asP,enols

mg * (b) (b) 0.1 0.05 0.5 0.1

Total Coli orms 3P7 100m* (b) (b) 5 000 " 000 15 000 10 000

(a) 6xcept as ot,er8ise indicated all limiting alues in Tables 24 and 2B are &0t, percentile alues. T,is isapplicable onl- 8,en t,e disc,arger underta9es dail- monitoring o its e luent :ualit- ot,er8ise t,enumerical alues in t,e tables represent maximum alues not to be exceeded once a -ear.(b) isc,arging o se8age and or trade e luents is pro,ibited or not allo8ed

Table 2* - EFFLUENTS STANDARDS: Conventional and Other Pollutants in $nland!aters Class D) Coastal !aters Class SC and SD and other Coastal !aters not #etClassi+ied(

Para%eter Unit

$nland !aters Coastal !aters Class SD 'Other

Coastal!aters

&Class D( &Class SC( NotClassi+ied

OE$ NP$ OE$ NP$ OE$ NP$

Color PCU %%% %%% (c) (c) (c) (c)

Temperature(max. rise in deg. Celsius in RB )

!C rise " " " " " "

p# (range) 5.0%&.0 $.0%&.0 $.0%&.0 $.0%&.0 5.0%&.0

5.0%&.0

C' mg * 250 200 250 200 "00 200

5% a- 20 oC B' mg * 150 (d) 120 120 (d) 100 150(d)

120

Total +uspended +olids mg * 200 150 200 150 (g) ( )

Total issol ed +olids mg * 2 000(,) 1 500(,) % % % %

+ur actants (3B4+) mg * % % 15 10 % %

'il rease (Petroleum6t,er 6xtract)

mg * % % 15 10 15 15

P,enolic +ubstancesas P,enols

mg * % % 1.0(i) 0.5(i) 5.0 1.0


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Total Coli orms 3P7 100m* (;) (;) % % % %

(c) isc,arge s,all not cause abnormal discoloration in t,e recei ing 8aters outside o t,e mixing


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APPENDI/ 3

ACTI ATED SLUDGE TERMS#

Vr * Vt = Reactor volume 2=gal3 2m/3

F M %ood-to-microorganism ration,or process loading #actor? mass !g o# #resh B D0 applied to the activated sludges&stem per da& per !g o# =>VSS in the aeration "asin, 2!g B D @ da& 3 @ 2!g =>VSS3

SRT = Sludge or Solid Retention Time or the average time that the sludge remains in the reactor 2sludge age3.The design o# the reactor is "ased on SRT on the assumption that su"stantiall& all the su"strate 2B D3 conversion occursin the reactor. Total mass !g 2g3 o# =V>SS in aerator per !g 2g3 o# VSS wasted per da&2or net solids produced3, da&s

Q = )verage dail& in#luent #low rate 2=gd3

Y = =a'imum &ield coe##icient 2mg VSS@mg B D03. Essentiall&, Y represents the ma'imum mg o# cells produced per mgorganic matter . %or the activated sludge process #or domestic wastewater Y ranges #rom +.6 to +. . S0 = n#luentsu"strate 2B D03 concentration 2mg@>3 : 86+ mg@>

S = E##luent su"strate 2B D03 concentration 2mg@>3 : 9+ mg@>

X VSS = 7oncentration o# microorganisms in reactor : =i'ed >iquor Volatile Suspended Solids 2=>VSS3 in mg@>. t isgenerall& accepted that the ratio =>VSS@=>SS X +. , where =>SS is the =i'ed >iquor Suspended Solidsconcentration in the reactor. =>SS represents the sum o# volatile suspended solids 2organics3 and #i'ed suspended solids2inorganics3. %or a complete-mi' activated sludge process, =>SS ranges #rom 9,+++ to *,0++ mg@>.

kd = Endogenous deca& coe##icient (d -1 ) which is a coe##icient representing the decrease o# cell mass in the =>VSS. %orthe activated sludge process #or domestic wastewater kd ranges #rom +.+80 to +.+H0 d -1.

RT , h&draulic retention time ( τ ) in the reactor is the reactor volume divided "& the in#luent#low rateL r ! " . %or a complete-mi' activated sludge process, τ is generall& /-0 hours.

Yobs "served cell &ield, No"s : N@29 F kd#SRT 3 = +.* @29 F 2+.+* d-9 )#(8d)) = +.69 mg@mg representsthe actual cell &ield that would "e o"served. The o"served cell &ield is alwa&s less than the ma'imum cell &ield (Y).

Px $%% is the net waste activated sludge produced each da& in 2 " VSS@d3.&'= Yo % # " # (So - S3 G 2 ./6 "@=gal@mg@>3

MLSS =i'ed >iquor Suspended Solids? suspended solids in the aerator mi'ed liquor, mg@>

MLVSS represents the increase o# volatile suspended solids 2organics3 in the reactor. # course the total increase insludge mass will include #i'ed suspended solids 2inorganics3 as well. There#ore, the increase in the total mass o# mi'edliquor suspended solids, =>SS, represents the total mass o# sludge that must "e wasted #rom the s&stem each da& and isshown "&.

2=>SS3 : &'(%%) = 2g VSS@d3@2+. 3

SCFM or SCMM Standard cu"ic #eet or meter o# gas, measured at a dr& pressure o# 9.+ atmosphere29+.9/!P)3 and8+deg7

SVI Sludge Volume nde'? volume in millimeters occupied "& 9 gram o# activated sludge, a#ter settling the aerated mi'edliquor #or /+ mins in a 9+++-m> graduated c&linder.

bCOD Biodegrada"le 7hemical '&gen Demand- the amount o# o'&gen in mg@> requied to o'idi(e "oth organic ando'idi(a"le inorganic compunds or su"stances. 2This is B D in terms o# 7 D, 7 D is used in mass "alance operation toaccuratel& surve& characteri(e the decomposition o# ca"onaceous material "etween the amount o'idi(ed and amountincorporated into cell massYJ9K3

Ultimate arbo!a eo"s ox#$e! dema!d %&ODL'

The theoretical o'&gen requirements are calculated using the B D0 o# the wastewater and the amount o# organisms 2P'3wasted #rom the s&stem each da&. # all B D0 were converted to end products, the total o'&gen demand would "ecomputed "& converting B D0 to ultimate B D 2B D >3, using an appropriate conversion #actor. The Z uantit& o# Sludge$astedZ calculation illustrated that a portion o# the incoming waste is converted to new cells which are su"sequentl&wasted #rom the s&stem.There#ore, i# the B D > o# the wasted cells is su"tracted #rom the total, the remaining amount represents the amount o#o'&gen that must "e supplied to the s&stem. %rom stoichiometr&, it is !nown that the B D > o# one mole o# cells is equal to9.68 times the concentration o# cells. There#ore, the theoretical o'&gen requirements #or the removal o# the car"onaceousorganic matter in wastewater #or an activated-sludge s&stem can "e computed using the #ollowing equationL


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" 8@d : 2total mass o# B D > utili(ed, "@d3 - 9.68 2mass o# organisms wasted, "@d3

sing terms and quantities that have "een de#ined previousl& where # : conversion #actor #or convertingB D0 to B D > 2# : +.* is commonl& used3L

l" 8@d : J G2So-S3 G 2 ./6l"@=gal@mg@>3K @ # K - 9.68GP'

= =i'ed >iquor Suspended Solids 2=>SS3"r = Return activated sludge pumping rate 2=gd3

r = 7oncentration o# sludge in the return line 2mg@>3. $hen lac!ing site speci#ic operational data, a value commonl&assumed is +++ mg@>."e = E##luent #low rate 2=gd3

e = 7oncentration o# solids in e##luent 2mg@>3. $hen lac!ing site speci#ic operational data, this value is commonl&assumed to "e (ero."* : $asted )ctivated Sludge 2$)S3 pumping rate #rom the reactor 2=gd3"*+ = $aste )ctivated Sludge 2$)S3 pumping rate #rom the return line 2=gd3

7ontrol Parameter 7ontrol o# the activated sludge process is important to maintain high levels o# treatment per#ormance under a wide range o#operating conditions. The principle #actors used in process control are 293 maintaining dissolved-o'&gen levels in the aerationtan!s, 283 regulating the amount o# Return )ctivated Sludge 2R)S3, and 2/3 controlling the $aste )ctivated Sludge 2$)S3. )soutlined previousl& in Part 0 Z7ompute the %ood to =icroorganism Ratio and the Volumetric >oading,Z the most commonl& usedparameters #or controllingthe activated sludge process are the %L= ratio and the Sludge Retention Time or mean cell residence time SRT .The =i'ed >iquor Volatile Suspended Solids 2=>VSS3 concentration ma& also "e used as a control parameter. Return )ctivatedSludge 2R)S3 is important in maintaining the =>VSS concentration and the $aste )ctivated Sludge 2$)S3 is important incontrolling the mean cell residence time 2+73.

The e'cess waste activated sludge produced each da& wasted #rom the s&stem to maintain a given %L= or mean cell residencetime. enerall&, sludge is wasted #rom the return sludge line "ecause it is more concentrated than the mi'ed liquor in theaeration tan!, hence smaller waste sludge pumps are required. The waste sludge is generall& discharged to sludge thic!eningand digestion #acilities. The alternative method o# sludge wasting is to withdraw mi'ed liquor directl& #rom the aeration tan!where the concentration o# solids is uni#orm.

Pump RequirementsLThe actual amount o# liquid that must "e pumped to achieve process control depends on the method used and the location #romwhich the wasting is to "e accomplished. )lso note that "ecause the solids capture o# the sludge processing #acilities 2i.e.,thic!eners, di-gesters, etc.3 is not 9++ percent and some solids are returned, the actual wasting rate will "e higher than thetheoreticall& determined value. ;ote that the required R)S pumping rate can "e determined "& per#orming mass "alance aroundthe aeration tan! thus the #ollowing equation can "e usedL

wM :Vr G @ 2SRT G r3rsing the ratio o# R)S pumping rate to in#luent #low rate, or recirculation ratio 2a3, asL

a : r @ ,

Recirculation ratio can var& #rom +.80 to 9.0+ depending upon the t&pe o# activatedsludge process used. 7ommon design practice is to si(e the R)S pumps so that the& arecapa"le o# providing a recirculation ratio ranging #rom +.0+ to 9.0+. the r can "e calculated

r : a G

t should "e noted that i# the control volume were placed around the aeration tan! #or conventional reactor or the control volume placed around the settling tan! and a mass "alance per#ormed, that a slightl& higher R)S pumping ratewould result.


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Ae *+!' re#ers to a li#e or a process that occurs in the presence o# o'&gen.

Ae *+!' T e$)%en) Un!), provide wastewater treatment "& inQecting air into a tan!, allowing aero"ic "acteria to treat thewastewater.

An$e *+! c re#ers to a li#e or a process that occurs in the a"sence o# #ree o'&gen.

B$')e !$ are small living organisms which help consume the organic constituents o# sewage.

B$ S' een is composed o# parallel "ars that remove larger o"Qects #rom

B&$' $)e is the term given to domestic wastewater that carries animal, human, or #ood wastes.

B!*&* !'$& N() !en) Re%* $& 7BNR is the use o# "acteria to remove nutrients #rom wastewater.

B!*%$,, is micro"ial growth.

B!*,*&! , are treated sewage sludge solids that have "een sta"ili(ed to destro& pathogens and meet rigorous standardsallowing #or sa#e reuse o# this material as a soil amendment.

B!*)* e is a unit in which the waste is allowed to #all through a tower pac!ed with s&nthetic media on which there is"iological growth similar to the tric!ling #ilter.

BOD 7B!*':e%!'$& O"; en De%$n is a measure o# o'&gen consumed in "iological processes that "rea! downorganic matter in water.

C$ +*n A ,* p)!*n is a method to treat wastewater in which activated car"on removes trace organic matter thatresists degradation.

C:&* !n$)!*n is the process o# adding chlorine gas or chlorine compounds to wastewater #or disin#ection.

C:&* !n$)* is a device that adds chlorine, in gas or liquid #orm, to wastewater to !ill in#ectious "acteria.

C&$ !-!e also !nown as a settling tan!, removes solids #rom wastewater "& gravit& settling or "& coagulation.

C&e$n $)e A')


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D!,,*& e O"; en 7DO is the amount o# #ree o'&gen in solution in water, or wastewater e##luent. )dequateconcentrations o# dissolved o'&gen are necessar& #or #ish and other aquatic organisms to live and to prevent o##ensiveodors.

E--&(en) is the treated liquid that comes out o# a treatment plant a#ter completion o# the treatment process.

E() *p:!'$)!*n is the normall& slow aging process "& which a la!e evolves into a "og or marsh and ultimatel&disappears. During eutrophication, the la!e "ecomes enriched with nutrients, especiall& nitrogen and phosphorus, whichsupport the e'cess production o# algae and other aquatic plant li#e. Eutrophication ma& "e accelerated "& man& humanactivities.

F&*' is a clump o# solids #ormed in sewage "& "iological or chemical action.

F&*''(&$)!*n is the process "& which clumps o# solids in sewage are made to increase in si(e "& chemical action.

G $; $)e re#ers to domestic wastewater composed o# wash water #rom sin!s, shower, washing machines2does not include toilet wastewater3.

G !n e P(%p is a mechanical device which shreds wastewater solids and raises the #luid pressure level highenough to pass wastewater through small diameter pressure sewers.

G !) C:$%+e is a small detention "asin designed to permit the settling o# coarse, heav& inorganic solids, suchas sand, while allowing the lighter organic solids to pass through the cham"er.

In'!ne $)!*n involves com"ustion o# the organic matter in sewage sludge, producing a residual inert ash.

In-!&) $)!*n is the penetration o# water through the ground into su"-sur#ace soil or the passing o# water #rom thesoil into a pipe, such as a sewer.

In-&(en) re#ers to water, wastewater, or other liquid #lowing into a reservoir, "asin or treatment plant, or an& unit thereo#.norganic re#ers to compounds that do not contain car"on.

In)e 'ep)* , are large sewer lines that collect the #lows #rom smaller main and trun! sewers and carr& them to thetreatment plant.

In)e %!))en) ,$n -!&)e involves a "ed o# sand or other #ine-grained material to which wastewater is appliedintermittentl& in #looding doses.

Me':$n!'$& Ae $)!*n uses mechanical energ& to inQect air #rom the atmosphere into water to provide o'&gen tocreate aero"ic conditions.

Me !$ F!&)e , involves a "ed o# sand or other #ine-grained material to which wastewater is applied, generall& toph&sicall& remove suspended solids #rom sewage. Bacteria on the media decompose additional wastes. Treated waterdrains #rom the "ed. Solids that accumulate at the sur#ace must "e removed #rom the "ed periodicall&.

M!' *+e, is shorthand #or microorganisms.

M!&&!*n G$&&*n, Pe D$; 2= D3 is a measurement o# the volume o# water.

M*(n S;,)e% is an e##luent disposal s&stem involving a mound o# soil "uilt up on the original ground sur#ace towhich e##luent is distri"uted.

N!) !-!'$)!*n is the "iochemical o'idation o# ammonium to nitrate.

N!) * en*(, $,)e, are wastes that contain a signi#icant concentration o# nitrogen.

N() !en), are elements or compounds essential as raw materials #or plant and animal growth and development.

O $n!' M$))e is the car"onaceous material contained in plants or animals and wastes.

O"! $)!*n involves aero"ic "acteria "rea!ing down organic matter and o'&gencom"ining with chemicals insewage.

P$):* en, are disease-causing microorganisms, including pathogenic "acteria, viruses, helminths, and proto(oans.


20/20

P:*,p:* (, is a nutrient that is essential to li#e, "ut in e'cess, contri"utes to the eutrophication o# la!es andother water "odies.

P*&;%e is a long chain organic compound produced "& the Qoining o# primar& units called monomers. Pol&mersare used to improve settling o# suspended solids, remove solids #rom wastewater, and improve dewatering o# "iosolids.

P !%$ ; T e$)%en) is the initial stage o# wastewater treatment that removes #loating material and material that easil&settles out.

R*)$)!n B!*&* !'$& C*n)$')* 7RBC is a wastewater treatment process involving large, closel&-spaced plastic discsrotated a"out a hori(ontal sha#t. The discs alternatel& move through the wastewater and the air, developing a "iologicalgrowth on the sur#ace o# the discs that removes organic material in the wastewater.S$n!)$ ; Se e is the collection s&stem #or transporting domestic and industrial wastewater to municipal wastewatertreatment #acilities. Stormwater is not directed into this s&stem "ut is handled "& a separate s&stem.

Se'*n $ ; T e$)%en) is the second stage in most wastewater treatment s&stems in which "acteria consume the organicmatter in wastewater. %ederal regulations de#ine secondar& treatment as meeting minimum removal standards #or B D,TSS, and p< in the discharged e##luents #rom municipal wastewater treatment #acilities.

Se !%en)$)!*n T$n , are wastewater treatment tan!s in which #loating wastes are s!immed o## and settledsolids are removed #or disposal.

Seep$ e is the slow movement o# water through small crac!s or pores o# the soil, or out o# a pond, tan! or pipe.

Sep)$ e re#ers to the residual solids in septic tan!s or other on-site wastewater treatment s&stems that must"e removed periodicall& #or disposal.

Sep)!' T$n , are a t&pe o# onsite wastewater treatment s&stem in which the organic waste is decomposed and solidssettle out. The e##luent #lows out o# the tan! to a soil adsorption #ield or other dispersal s&stem.

Se=(en'!n B$)': Re$')* , 7SBR are a variation o# the activated sludge process where all treatment processes occur

in one tan! that is #illed with wastewater and drawn down to discharge a#ter treatment is complete.

Se))&e$+&e S*&! , are solids that are heavier than water and settle out o# water "& gravit&.

Se e , are a s&stem o# pipes that collect and deliver wastewater and@or stormwater to treatment plants or receivingwaters.

S*!& A+,* p)!*n F!e& is a su"sur#ace area containing a trench or "ed with a minimum depth o# 98 inches o# clean stonesand a s&stem o# piping through which treated wastewater e##luent is distri"uted into the surrounding soil #or #urthertreatment and disposal.

S(,pen e S*&! , are the small particles suspended in water or wastewater.

T !' &!n F!&)e is a #i'ed #ilm process that involves a tan!, usuall& #illed with a "ed o# roc!s, stones or s&ntheticmedia, to support "acterial growth used to treat wastewater.

U&) $ !*&e) R$ !$)!*n 7U is a disin#ection process where wastewater is e'posed to V light #or disin#ection.

$,)e $)e T e$)%en) P&$n) is a #acilit& involving a series o# tan!s, screens, #ilters, and other treatment processes"& which pollutants are removed #rom water.

approx waste watertreatment fac power requirements revd

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