Wastewater characteristics

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Wastewater characteristics

Nidal Mahmoud

Institute of Environmental and Water Studies, Institute of Environmental and Water Studies,,, Birzeit University Birzeit University [email protected]

Ecological Sanitation Training Course

SWITCH PROJECT IEWS, Birzeit University, 25-27 January 2011

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Outline

• Introduction

• General characteristics

• Wastewater parameters

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Introduction

• Why wastewater characterization

y

• Wastewater characteristics for a certain community

could change with time depending on technologies

available.

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Introduction

Water quality is described by a series of water quality

• Water quality is described by a series of water quality

parameters

• A water quality parameter refers to a property of water

A water quality parameter refers to a property of water

(such as color, taste, turbidity) or to the composition of

water.

• The composition of water can be expressed in the

concentration of individual compounds or it can be

expressed in the concentration of a group of related

compounds, such as Biochemical Oxygen Demand

(BOD), these are called lump parameters.

• Substances present in water are either in solid, liquid, or

gas form.

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Introduction

Water Quality Q y Parameters

Physical parameters Chemical parameters Microbiological parameters TS COD lif TS COD coliform VS BOD TSS Nkj-N pH NH4-N pH NH4 N Turbidity NO3 conductivity PO4 SO4

Water analysis is essential in:

The design and operation of collection, treatment, and reuse facilities To asses reactor performance

To comply with standards others

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Main components of wastewater characteristics

A distinction can

also be made

according

to

particle

size

(important

in

(important

in

water

treatment

as

the

required

the

required

treatment

process

d

th

depends on the

size of particles

to

b

e

d

l

removed; also

in

water

treatment).

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COD fractions

Raw sewage

Suspended COD

(CODss)

4.4 

m paper-filtered sewage

(CODss)

Colloidal COD (CODcol)

0.45 

m membrane filtered

sewage

Dissolved COD

_(CODdis)

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Main components of wastewater characteristics

Physical- Chemical Parameters Importance Parameters ________________ 1 Temperature o_C ___________________________________ Affects chemical reactions and reaction 1. Temperature C

rates. Low temperature affects bacterial growth.

2. pH _{Affects chemical biochemical reactions as} well as biological activities.

3. Turbidity Due to presence of colloidal matter. When high SS concentration present in WW it high SS concentration present in WW, it could be resistant to removal when

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Main components of wastewater characteristics

Physical- Chemical Parameters Importance _______________ 4. Suspended Solids (SS) _____________________________

Hydrolysis of suspended solids may be the rate limiting step under anaerobic

(SS) _{rate limiting step under anaerobic} conditions especially at low

temperatures. They also cause

disintegration of granular sludge and disintegration of granular sludge and results in lower methanogenic activity. Aff t i ki ti f th d d 5. Particle size

distribution

Affects conversion kinetics of the suspended solids.

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Main components of wastewater characteristics

p

Physical- Chemical Parameters Importance ________________ 6. Polymeric tit t ___________________________________ They consist mainly of carbohydrates,

proteins and lipids and should be constituents

(COD)

proteins and lipids and should be

removed with treatment. They constitute the main part of the COD of wastewater. 7. Refractory organics

These compounds tend to resist

conventional wastewater treatment. T i l l f t t

Typical examples are surfactants,

phenols and agricultural pesticides. The presence of surfactants also affects

stabilization of colloids and the surface stabilization of colloids and the surface properties of particles.

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Main components of wastewater characteristics

Physical- Chemical y Importance Parameters

________________

p

___________________________________ Organic and inorganic compounds selected 8. Priority pollutants Organic and inorganic compounds selected _{on the basis of their known or suspected}

carcinogenic, high acute toxicity. Many of these compounds are found in

these compounds are found in wastewater.

Hi h t ti i hibiti f 9. Sulphate High concentration causes inhibition of

methanogenesis.

10. Chloride It may have an impact on the final use of treated wastewater

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Main components of wastewater characteristics

p

Physical- Chemical Parameters Importance ________________ 11. Heavy metals ___________________________________ Toxic to bacteria. I t i t 11. Heavy metals 12 N i Impact on environment. 12. Nutrients Macro (N,P,K) and micronutrients

Important for biological treatment processes.

13. Biological

Parameters Includes pathogenic microorganisms, and all _th _i _{ti i ti} _i Parameters _{other organisms participating in}

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Effect of Temperature

• Three ranges of temperature

• Effect of low temperature: low methanogenic activity;

low hydrolysis rate.

• Temperature has also a direct impact on the physical

chemical characteristics of the solids and solution,

including the ability to form a scum layer It also affects

including the ability to form a scum layer. It also affects

the solubility of gases.

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Effect of pH

• Many inhibitory substances for methanogenic bacteria are controlled by pH. For example, organic acids are inhibitory to methanogenic b t i l i th i i d f hi h i i l d t i d b bacteria only in the unionized form which is mainly determined by the pH of the solution.

Optim m pH fo mic oo ganisms g o th • Optimum pH for microorganisms growth

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Turbidity of wastewater

• Turbidity is an indication of the clarity of a water • Turbidity is as an optical property Light source Light source property

• Presence of colloidal particles. SlitSlit • Determination of colloidal

fraction

Sample _Phototube Sample _Phototube

fraction.

• Colloidal particles in anaerobic p _{Schematic diagram of a nephelometer} reactor. Schematic diagram of a nephelometer

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Turbidity of wastewater

Measurement of gas production

Primary

ffl t From: Mels (2001) Turbidity measurements are often

used to monitor the performance

of treatment works processes: on– R t

effluent

Turbidity measurement

( )

TSS mg/l ≈ TSSfx T

of treatment works processes: on

line measurement Reactor with filter material

Clarifier

Primary effluent Polymer dosing pump

TSS, mg/l ≈ TSSfx T Where,

TSS = total suspended solids, mg/l Influent Coagulation mixing Flocculation mixing Sludge discharge Sludge discharge Relation mg/l

TSSf = factor used to convert turbidity readings to total

suspended solids, (mg/l 200 250 300 350 D (> 0 .4 5 µm ) between turbidity and ti l t suspended solids, (mg/l TSS)/NTU T = turbidity, NTU y = 2.46x R2_{= 0.986} 0 50 100 150 P a rt ic ul at e CO D particulate COD (> 0.45 µm) as found in the 0 25 50 75 100 125 150 NTU found in the jar test experiments

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Total Suspended Solids

• Definition: portion of solids retained on the p Whatman glass fiber filter, which has a nominal size of about 1.58 µm

• Determination: Filtration, drying (105 °C), weighing

• Problems with the test: sensitive to moisture • Importance of the test: biological and p g

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Particle Size Distribution

There is no universal agreement on particle size distribution

Type of matter Particle size

Suspended matter > 1 µm

There is no universal agreement on particle size distribution

Type of matter Particle size

Suspended matter > 4.4 µm

p µ

Colloidal matter 0.001 – 1 µm

Dissolved (or soluble) <0.001 µm

Colloidal matter 0.45 – 4.4 µm

Dissolved (or soluble) <0.45 µm

Importance Importance

• First step in biodegradation process

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Sulphate concentration

• Sulphate reducing bacteria are able to oxidize part of the COD present in the wastewater by utilizing sulphate as an electron acceptor.

acceptor.

• When sulphate concentration is high, then sulphate reducing bacteria will compete methanogenic bacteria and little CH4 is bacteria will compete methanogenic bacteria and little CH4 is produced.

f

• Sulphate reducing bacteria grow at a wide range of pH (5-9).

Sulphate reduction can not be controlled in anaerobic reactor except when the SO4- concentration is limited. Fortunately, in domestic

l h t t ti i ll l f l 50 sewage, sulphate concentration is generally low, for example, 50-200 mg/l.

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Polymeric Constituents

• For domestic sewage, the percentage of each polymer may be

different from one community to another depending on the lifestyle and standards of living of a society.

• Composition affects the biodegradation process as some polymers, for example, carbohydrates are more readily biodegradable than for example, carbohydrates are more readily biodegradable than lipids.

• Organic pollutants in wastewater can be divided into easily • Organic pollutants in wastewater can be divided into easily

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Biochemical oxygen demand (BOD)

Theoretical oxygen demand (ThOD). Theoretical oxygen demand (ThOD). Organic matter: CnHaObNc

CnHaObNc+{n + a/4 –b/2 – 3c/4}O2 nCO2 + {a/2 – 3c/2}H2O + cNH3

BOD: defined as the amount of oxygen required to oxidize organic

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Priority Pollutants

• The EPA has identified approximately 129 priority pollutants (both organic and inorganic substances), which are suspected to be

carcinogenic mutagenic or have high toxicity carcinogenic, mutagenic or have high toxicity.

• Many of the organic priority pollutants are also classified as volatile

i d h d d di h i i

organic compounds. These compounds vary depending on the origin of wastewater.

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Refractory organic compounds

• A typical example on refractory organic compounds is surfactants; or surface active agents

or surface active agents.

• These are large molecules that are slightly soluble in water and g g y

cause foaming in wastewater treatment plants. They tend to collect at the air water interface. During aeration of biogas production,

these compounds collect at the surface of gas bubbles causing a these compounds collect at the surface of gas bubbles causing a very stable foam which difficult to remove.

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Composition of domestic sewage for different

countries

(Adopted from Mahmoud et al., 2003)

Parameter* Jordan Palestine Egypt The Netherlands Columbia, Cali

CODt 1183 1586 825 528 267 CODss 608 919 225 CODcol 174 274 156 CO co 56 CODdis 401 393 270 147 112 VFA-COD 104-177 160 55 NH4-N 80 80 26 48 17 NH4-N 80 80 26 48 17 Nkj-N 109 104 34 70 24 Total P 13 9 18 1 PO 3 _P ₁₃ ₄ ₁₄ PO₄-3 _-P ₁₃ ₄ ₁₄ Lipids-COD 443 302 Protein-COD 272 224 TSS 420 736 310 215 VSS 330 617 277 108 VSS/TSS 79 84 89 50 Temperature 16-24 8-20 25

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Biodegradability and Biodegradation rate of sewage

• Definition of

O 10% O 10% O %

biodegradability

NaOH 10% Septum NaOH 10% NaOH 5% Septum

• Procedure used for

determination

Serum bottle with ca. 5 g sludge COD

+ 1 ml NaOH solution = 1 ml of CH4 produced = 2 5 mg

Serumbottle with ca. 5 g sludgeCOD

+ 1mlNaOHsolution = 1 ml of CH4 produced = 2 5 mg

• Determination of

granular sludge

(1 g VSS) 30 degr.

1 ml NaOH solution = 1 ml of CH4 produced = 2.5 mg COD degraded

granularsludge (1 g VSS)

30°C .

1mlNaOHsolution = 1 ml of CH4 produced = 2.5 mg CODdegraded

biodegradation rates of

different polymers.

50% 60% 70% 80% 90% 100% gra de d pa rt 0% 10% 20% 30% 40% 50% 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 Biode g time (days)

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Composition of wastewater (polymeric constituents)

p

(p y

)

Average percentages of carbohydrates, lipids and proteins for the two influents compared to data presented in literature

two influents, compared to data presented in literature.

Values in brackets are percentages of TSS

Khirbit

As-Samra Abu-Nusier McInery,(1988)( ) Elmitwalli,(2001)( ) Carbohydrates 5 (21.8) 5 (15) (12.8) 9-17 P i 45 (28) 48 (27 1) 31 58 Proteins 45 (28) 48 (27.1) 31-58 Lipids 23 (34) 31 (39) (34.4)

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---Biodegradability of wastewater

Biodegradability of wastewater

Biodegradability of the wastewaters Biodegradability of the wastewaters Time (day) 130 224 Khi bit A S 56 1 78 4 Khirbit As-Samra 56.1 78.4 Abu-Nusier 75.8 (8.6)

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---Wastewater Characteristics of Ramallah City, Al - Bireh City and Al-Jalazoon refugee camp

Parameters # Samples Ramallah Al-Bireh Al-Jalazoon

Range AVR STD Range AVR STD Range AVR STD COD Total 8 1518-3812 2180 663 1411-1844 1586 125 1092-1773 1489 251 Suspended 8 545 – 1925 1096 456 720-1209 919 157 518-990 725 153 Colloidal 8 107 525 323 101 171 362 274 52 4 213 440 327 71 3 Colloidal 8 107- 525 323 101 171-362 274 52.4 213-440 327 71.3 Dissolved 8 468-1482 761 297 280-464 393 62.3 258-613 438 113 Carboh. Total 5 100-231 178.4 52.6 99-166 131 22.8 59-155 93.5 32.7 Suspended 5 45-90 64.1 20.2 67-132 97.4 25.3 28-88 44.8 21.3 Colloidal 5 10-35 21.6 10 9-14 11.7 1.8 4-14 9.9 3.7 Dissolved 5 37-157 92.6 55.4 17-37 22.2 7.4 15-60 38.8 17.3 VFA as COD 2 175-199 187 12 155-162 160 3.1 100-145 123 25.4 Nkj as N 6 54-119 99.4 23.2 85-122 104 14.7 53-83 71 10 NH4+ as N 8 47-72 58 8.5 72-89 80.1 5 40-77 56.2 9.5 +_Proteins ₃₈₈ ₂₂₄ ₁₃₉ Total PO4as P 3 10-15 12.8 2.2 11-14 13 1.5 11-18 15 2.4 PO43- as P 5 6-17 12.4 3.8 8-15 12.9 2.6 8-14 11.9 2.4 SO42- as SO42- 4 474-2060 975 742 129-151 138 9.9 143-277 213 57 TSS 5 510-1096 729 197 610-824 736 67 408-1048 630 234 VSS 5 255 892 584 209 492 676 617 66 1 364 733 480 148 VSS 5 255-892 584 209 492-676 617 66.1 364-733 480 148 Settleable solids 7 4-105 43.5 41.1 8.5-13.5 10.9 2.2 1.2-8 2.9 2.4 pH 4 7.18-8.02 7.45 0.39 7.16-7.44 7.26 0.13 7.11-7.58 7.31 0.2 Tww Summer 8 26-40 30.9 3.19 24-27 25.8 0.67 20-25 23.4 1.52 Winter 4 12-13 13.13 0.63 Tamb. Summer 8 21-33 27.1 3.17 Winter 4 11-17 13.8 2.75 Biodegradability 2 46-49 47 1.4 34-40 36 3.2 32-35 33 1.5

Colour 8 Reddish to black Medium brown Light brown

All parameters have been measured in duplicate and their units are in mg/l except settleable solid in ml/l; wastewater temperatures (Tww) and ambient temperature (Tamb) (o C); pH no unit; Biodegradability (%); Proteins mg COD/l

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Percentages of hydrolysis and acidification of total COD and

acidification of dissolved COD and VSS/TSS and CODss/VSS ratios for the sewage of Ramallah and Al Bireh cities and AL Jalazoon

P t R ll h Al Bi h AL J l

for the sewage of Ramallah and Al-Bireh cities and AL-Jalazoon refugee camp-Palestine

Parameter Ramallah Al Bireh AL-Jalazoon

Acidified fraction VFA/CODt 10 10 9

Acidified of dissolved VFA/CODdis 27 36 35

H d l d f ti CODdi /CODt 39 28 25

Hydrolysed fraction CODdis/CODt 39 28 25

VSS/TSS 80 84 76

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P t f b h d t t i d VFA t f t t l COD f Percentages of carbohydrates, proteins and VFA out of total COD for domestic/municipal wastewater of Ramallah, Al-Bireh cities and

AL-Jalazoon refugee camp-Palestine and Bennekom village-The Netherlands Parameter Ramallah Al-Bireh AL-Jalazoon Bennekom-The Netherland Carb-COD/CODt 8.8 8.9 6.7 12

P otein COD/CODt 18 14 9 44 Protein-COD/CODt 18 14 9 44

VFA/CODt 10 10 9 9 Sub total COD 36.8 32.9 24.7 65

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Gray wastewater characteristics of 25 houses in Biet-Diko

Item BOD5 COD pH EC TDS SVI TS TSS Cl- HCO3- NH4+ NO3- SO42-PO43-Ca2+ Mg2+Na+ K+ FC

Gray wastewater characteristics of 25 houses in Biet-Diko and Bilien villages/Palestine

Unit mg/l mg/l μs/ cm ppm ml/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l CFU/ 100 ml value 590 1270 6.6 1585 935 11.4 1780 1396 255 230 3.8 38 74 4.4 75 35 126 16 60