8 -W.W Characteristics02 Environment Engineering.pptx

ENVIRONMENT ENGINEERING

1. Environment Engineering (W.W Characteristics)

2. W A STE W A TER C H ARA C TE R ISTI C S I mpo r t a n c e : An unde r s tand i ng of the natu r e of w a ste w at e r i s e s s ent i al i n t he de si gn and ope r at i on of c o ll e c t i on, t r eatment, and d is po sal fa cili t i e s . Con s t i tu e nt s Foun d in W as t e w a t e r : W a ste w ater i s c ha r a cte r iz ed i n te rms of i ts Ph y sic a l , Chem ic al and Bi o l og ic al c ompo sit i o n .

3. P H YSIC A L C H A R ACT ERI S T ICS P h y s i c a l C ha r a c t e r i s t i c s i n c l ud e s olid s , t em p era tu re , c olo r , a n d odo r . 1 . SO L I D S : W a st e w a t er i s no r m al l y 9 9 . 9 per c e n t w a t er and . 1 per c ent s olid s . T he t y pes of s oli d s are t o t a l , s u s p e nded, s e t t leable, di ss ol v ed, v ola t ile and f i x ed s olid s . T ota l S olids : T o t al s olids c on t e n t of a w a st e w a t er i s de f ined as a l l t he m a tt er t hat r e m ains a s r e s idue upon e v apora t ion at 103 t o 105 o C .

4. P H YSIC A L C H A R ACT ERI S T ICS (Cont…) Su sp en d ed a nd D issol ved S olids : T h e s o li d s w h i ch a r e r e t a i ne d o n a f il t e r pa p e r ( o f 1 . 2 m i c r o m e t e r po r e s i z e ) a r e k no w n a s s u s pe nde d s o li d s an d t ho se t ha t pa ss t h r oug h i t a l on g w i th w a t e r a r e k no w n a s d i ss o l v e d s o li d s. Se ttl e a b l e S olids : Se tt l e ab l e s o li d s a r e t ho se s o li d s t h a t w i l l s e tt l e a t t h e b o tt o m o f a c on e s hape d c on t a i ne r i n a 6 m i n pe r i o d . Se tt l e ab l e s o li d s, e x p r e ss e d a s m L / L , a r e a n a p p r o x i m a te m ea s u r e o f t h e q uan t i ty o f s l ud g e t ha t w i l l b e r e m o v e d b y p ri m a r y s ed i m en t a t i o n .

5. 2 . T em p e r at u r e : T e m p e r a t u r e o f w a st e w a t e r i s s l i g h t l y h i ghe r t ha n t h a t o f w a t e r s upp l y . O p t im u m t e m pe r a t u r e s f o r ba c t e r i a l a c t i v i t y a r e i n t h e r a n g e f r o m abou t 2 5 to 3 o C . P H YSIC A L C H A R ACT ERI S T ICS (Cont…) 3 . Co l o r : Fresh w a s t e w a ter is u s ual l y a lig h t b rownish - gr a y i n color . Due to an a er o bic c o n dit i ons the co l or o f wast e water is b l ack t h e w a s t e water is often described as SEPTI C .

6. 4 . O do r : O do r s i n d o m e st i c w a st e w a t e r a r e c au s e d b y g a s e s p r odu c e d b y de c o m p o s i t i o n o f o r g an i c m a tt e r o r b y s ub st an c e s a d d e d to t h e w a st e w a t e r. P H YSIC A L C H A R ACT ERI S T ICS (Cont…)

7. C H EMI C A L C H A R A C T E R I S T I C S T he s e in c lud e ; 1. I N O R G A N I C S : O rganic m a t t e r s , I n organi c s , and Ga s e s . pH : D e f ined as neg a t i v e logri t hm o f h y droge n -i o n c on c en t ra t io n . Very i m por t ant para m e t er in c on t rol of W aste W ater T reatment P lant . A l ka li n i t y : M o st ly due t o bi c arbona t e s of c a l c ium and m agne s iu m . W a st e w a t er is s ligh t ly al k alin e

8. 1. I N O R G A N I C S : S u l f u r : A c c u m ula t ed H 2 S c an be o x idi z ed biologi c ally t o H 2 S O 4 w hi c h c au s es s e w er c orro s io n . CH EMIC A L C H A R ACT ERI S T ICS (Cont…) N i t r og e n : T o c on t rol algal g r o w t h in re c ei v ing w a t er s , re m o v al of N in w a st e w a t er prior t o i t s di sc harge is de s irabl e .

9. CH EMIC A L C H A R ACT ERI S T ICS (Cont…) 1. I N O R G A N I C S : H ea v y M e t a l s : I nd i c a te i n c l u s i o n o f i ndu s t r i a l w a s t e s in s e w ag e . R e s u l ts in ad v e r s e hea l th i m pa c t s . I n t e r f e r e s w i th b i o l og i ca l t r ea t m ent . 2 . G A SE S : Di ss ol v e d O x y g e n: Its p r e s en c e i s ne c e ss a r y to a v o id a nae r o b i c c on d i t i on s a n d f o r ae r ob i c b i o l og i c a l t r ea t m en t o f w a s t e . H y d r og e n S ul f id e : C au s e s s e w e r c o rr o s i o n .

10. 3. O r g a n ic M a tt er : Organic c on s t i t u e n t s are c arboh y d r a t e s , pro t ein s , and f a ts . T o t al quan t i t y of organic m a t t er is m ea s ured by bio c he m i c al o x y g en de m and (BO D ) , c he m i c al o xy gen de m and ( C O D ) and t o t al organic c arbon ( T O C ). CH EMIC A L C H A R ACT ERI S T ICS (Cont…)

11. Biochemical Oxygen Demand (BOD) : “It is the amount of oxygen required by bacteria to oxidize organic matter to stable end products such as CO2 and water.” Chemical Oxygen Demand (COD) : “It is the amount of oxygen required to oxidize the organic matter chemically by using a strong oxidizing agent (K 2 Cr 2 O 7 ) in an acidic medium (H2SO4).” COD values are typically higher than BODs. Total Organic Carbon : The test indicates the total amount of carbon present in a wastewater sample.

12. B A CT E RIO L O G I C AL C H A R ACT E RIS T ICS Eno r m o u s q uan t i t i e s o f m i c r oo r g an i s m s a r e p r e s e n t i n do m e st i c s e w a g e . T he y i n c l ud e ; Ba ct e r i a W o r m s V i r u s e s P r o t o z o a e tc. Ba ct e r i a l c o un ts i n r a w s e w a g e m a y r an g e f r o m 5 , / m l to 5 , 00 , 00 / m l . C on c e r n s i n w a st e w a t e r r eu se o f a g ri c u l t u r a l i rr i g a t i on .

13. T ab l e : T y p i c a l C ha r a ct e ri st i cs o f D o m e st i c S e w a g e P a r a m e t e r T y p i ca l R a ng e ( mg / L ) T o t a l s o li d s 35 – 120 D i ss o l v e d s o li d s 25 – 85 S u s pende d s o li d s 10 – 35 S e tt l eab l e s o li d s ( m L / L ) 5 – 2 B O D 10 – 30 C O D 25 – 100 T o t a l N i t r oge n 2 – 8 5 Al k a li n i t y , m g / L a s C a C O 3 5 - 20