WASTEWATER

Wastewater

- used water (from human activity)

- contains pollutants

Pollutant

- In the recipient the creature’s life circumstances (significant changes in the existing biological, biochemical processes)

and thefurther use of water for

humans will be limited or impossible

Other problems

- aesthetic problems

- odour problems

- infection problems

CLOSED sewerage system from the source to the recipient

History

In the antique Rome was sewerage system also, and it caused no problem.

Why is it a problem nowdays?

What happend with the wastewater in the past years?

Organic substances

- micro-organisms eat the most of it

2 CH2 + 3 O2 → 2 CO2 + 2 H2O + energy+ cell material

LARGE OXYGEN-DEMAND!

Organic substances

- higher lifeforms cannot get enough oxygen

- photosynthesis is not enough

- that much oxigen cannot dissolve from the air

Solution

We have to reduce the amunt of organic materials getting into the

recipient↓

in order to keep the DO value above the critical level

(DO = Dissolved Oxygen)

Dangerous wastewater

ALWAYS:- infection danger PAST YEARS:- increasing population- urbanization- developing industry (chemicals)- concentration

Wastewater types

Domestic wastewater:

- human waste and washwater

from houses (homes)

Institutional wastewater:

- human waste and washwater

from public buildings andcommercial establishments

Wastewater types

- Industrial wastewater: used water from manufacturing processes - contains different chemical compounds

- Municipal wastewater: mixture of domestic and industrial wastewater

Wastewater types

Agricultural wastewater:

dung from keeping animals

Stormwater:

surface runoff caused by rainfall - carries organics, suspended and dissolved solids, etc.

Amounts

Domestic wastewater:

Developing countries: less than 100 L/pe/day

Middle-Europe: ~100 L/pe/day

Western countries: ~160 L/pe/day

Hungary: 90-100 (BP:180) L/pe/day

Amounts

Industrial wastewater:

- what kind of industry

- number of working factories and units

- type and level of the used technology

Industry

- cooling water

- producing chemicals

- producing food

- electronic industry

- textile industry

Amounts

Agricultural wastewater:

- what kind of animals

- number of the animals

- level of the used technology

Characterization

Chemical characterizationIndividual components:

• Sewage – impossible

• Industrial wastewaters – sometimes there is a possibility

• Municipal wastewater - impossible

Characterization

Group characterization:Carbon

• Chemical Oxygen Demand (CODCr= 400-800 mg/l)

• Biochemical Oxygen Demand (BOD5 = 200-400 mg/l, BOD7, BOD20)

• Total Organic Carbon (TOC)• Dissolved Organic Carbon (DOC)• Volatile Organic Carbon (VOC)

WATER POLLUTION:Oxygen deficiency

EFFECT OF RAW WASTEWATER

- BOD5 emission increases, BOD5

concentration increases, dissolved O2

concentration decreases

- O2 is an important water quality indicator

WATER QUAILTY (O2)- raw wastewater: 0 mg/l

- saturation concentration (Henry’s

law): ~ 10 mg/l (20 °C )

- fish reproduction: 6 mg/l (different

sensitivity: age, specie (eg. trout 6-7

mg/l, carp 4 mg/l)

- further water uses

BalanceBalance

ORGANIC MATERIAL (C, N)

SEDIMENT

RESPIRATIONDIFFUSION FROM AIR

PHOTOSYNTHESIS

TRIBUTARIES

ókmellékfolylégzésézisfotoszüledék

iónitrifikáclebomlásCdiffOKIBEdt

dCV

int

2IN – OUT + O2 diff – C decomposition – nitrification – sediment + photosynthesis – respiration +- tributaries

BOI O2

DISCHARGE O2 INPUT

SEDIMENTATION

01

234

567

89

0 100 200 300 400 500

x (km)

Old

ott o

xigé

n (m

g/l)

Streeter & Phelps Streeter & Phelps (1925(1925, River Ohio, River Ohio))

Characterization

Group characterization:

– Nitrogen– Phosphorus– Suspended solids– Other chemical, physical and biological

parameters

NITROGEN

ORGANICALLY BOUND

INORGANICAMMONIUM (NH4-N)

NITRATE (NO3-N)

NITRITE (NO2-N)

30 mg/l

50 mg/l

0.1 mg/l

0.5 mg/l

No exact values!!!

PHOSPHORUS

MAIN SOURCEDETERGENTS (50%)

HUMAN EXCRETA (50%)

ORGANICALLY BOUNDSOLID

INORGANICPOLYPHOSPHATES

ORTHOPHOSPHATES (PO43-)

DISSOLVED

TP

PHOSPHORUS

MAIN SOURCEDETERGENTS (50%)

HUMAN EXCRETA (50%)

ORGANICALLY BOUNDSOLID

INORGANICPOLYPHOSPHATES

ORTHOPHOSPHATES (PO43-)

DISSOLVED

TP

PHOSPHORUS

• ORGANICALLY BOUND0 - 4 mg/L

• POLYPHOSPHATES0 - 5 mg/L

• ORTHOPHOSPHATES (PO43-)

4 - 14 mg/L

• TOTAL PHOSPHORUS

8 - 14 mg/L

ESTIMATING POLLUTANT LOAD AND CONCENTRATION

BOD5: 60 g/d/person

COD: 120 g/d/person

TSS: 70 g/d/person

TN: 11 g/d/person

TP: 2.5 g/d/person

 

drinking water consumption: qd = 60-200

l/d/person 

ESTIMATING POLLUTANT CONCENTRATION

BOD5: 60 g/d/person

TN: 11 g/d/person

TP: 2.5 g/d/person

calculating with 200 l/d/person:

BOD5 concentration: 60/200 = 0.03 g/l = 300 mg/l

TN concentration: 11/200 = 0.055 g/l = 55 mg/l

TP concentration: 2.5/200 = 0.0125 g/l = 12.5 mg/l 

Other parameters

- pH

- temperature

- salt concentration ( ~ ability of leading electricity)

Europian Union

- All member state should follow some rules

- Derogation can be asked for

(Hungary: 2015)

Europian Union

- Difference between drinking water and the sewerage system supply

- Difference between sewerage system supply and treating the collected wastewater

Europian Union

Sensitive or non-sensitive area

More or less, than 2000 person’s emission