Transcript Waste Water Treatment

Waste Water Treatment Greece
Project by:
Pantelis Paschalakis
Nikos Daskalakis
Waste Water Treatment Europe
• First significant improvements in 1980’s
• Great changes over the past twenty years.
UWWT Directive
Decreases in discharges of
Eastern European
Countries
( EU – 10)
and accession countries
are due to economic recession.
Increased percentage
of
people connected to
WWT
Decline in
polluting manufacturing industries
Waste Water Treatment in Northern + Central Europe
Nordic Countries
Central Europe
Most of the population connected
to the highest levels of
tertiary treatment
( Removal of nutrients
and organic matter)
More than half of wastewater receives
tertiary treatment
Waste Water Treatment in Southern + East Europe
Southern and Eastern Europe
Accession Countries
Only half of the population
is connected to WWT.
30 to 40% is connected to
secondary or tertiary treatment.
Cause for this difference:
Policies to reduce eutrophication and improve bathing water quality
were implemented earlier in the northern and central
Than in the southern and eastern countries and in the accession countries
Improved surface water quality, including bathing water quality,
with a decrease in the concentrations of orthophosphates ,
total ammonium and organic matter over the past ten years
Waste Water Treatment directive
• Member States should identify water
bodies as sensitive areas.
Results of WWT
• An additional threat to the environment:
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Disposal of sewage sludge (Treatment
plants)
Has to be disposed of: 1)spreading on
soils, landfills or 2) incineration.
Disposal routes can transfer pollution
from water: 1)to soil or 2)air
Take into account in the respective policy
implementation processes
Waste Water Treatment Europe
Waste Water Treatment
Greece
Environment Minister
H.E. Mr. George Souflias
Environment-International agreements
Party to:
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Antarctic- Environmental Protocol
Antarctic- Marine Living Resources
Antarctic Treaty
Biodiversity
Climate change
Climate change- Kyoto protocol
Desertification
Environmental Modification
Hazardous Wastes
Law of the sea
Marine Dumping
Ship Pollution
Wetlands
WWT Research in Greece
I.
II.
Experimental and mathematical simulation of
filamentous bulking and foaming in the WWTP of
Ioannina
Consulting for the operation of the Volos WWTP
III. Wastewater reuse - Guideline development for pilot
artificial recharging of aquifers through direct injection
and irrigation, for seawater intrusion control within the
framework of integrated and sustainable water
management
WWT Research in Greece
IV.
V.
VI.
Bulking sludge phenomena in wastewater treatment
plants
Optimization of flow pattern in nutrient removal plants
to prevent bulking
Author Affiliation: Environmental Pollution Control
Laboratory, Department of Chemistry, Aristotle
University of Thessaloniki, Thessaloniki GR-54124,
Greece.
1
Experimental and mathematical simulation
of filamentous bulking and foaming in
the WWTP of Ioannina
• Laboratory and full scale experimental investigation of
filamentous bulking and foaming in activated sludge
systems. (Due to M. Pacivella)
• Laboratory simulation and analytical work: Engineering Lab
of N.T.U.A.
• Full scale investigation: WWTP, Ioannina city ( Population :
130,000)
WWTP in Greece facing operational problems due to excessive
bulking and foaming of activated sludge
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Consulting for the operation of the
Volos WWTP
Scope: Operation optimization of Volos WWTP
Objectives:
1. Determination of the quality characteristics of the
municipal and industrial wastewater
2. Wastewater and sludge characterization for toxicity
determinations
3. Mathematical modeling of the biological treatment for the
optimization of the operation of plant
4. Calibration of analytical apparatus
5. Intercalibration of analytical methods
6. Training of laboratory staff.
Volos WWTP
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Wastewater reuse - Guideline
development for pilot artificial
recharging of aquifers through direct
injection and irrigation, for seawater
intrusion control within the framework
of integrated and sustainable water
management
• Project aim: Promotion and dissemination
of wastewater reuse techniques
This project includes:
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Development of reuse guidelines in Greece and their evaluation in
a pilot scale unit for the artificial recharge of groundwater aquifer
by direct injection and irrigation of treated wastewater.
Control of salt water intrusion and groundwater level decrease
contributing to the principles of sustainable management of water
resources.
Dissemination and the application of the results in Greece and the
Mediterranean countries.
Main responsibilities of N.T.U.A. study:
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Survey of implemented wastewater reuse methods and critical
evolution of worldwide regulations and legislation governing
wastewater reclamation.
Definition of wastewater quality criteria for the alternative reuse
methods, suitable for the Mediterranean region and specifically
Greece.
Analysis of wastewater effluent quality from several WWTP in
Greece and assessment of their reclamation and reuse
possibilities.
Laboratory scale studies to investigate various treatment and
disinfection methods aiming to the development of the most
appropriate technology for wastewater reclamation in Greece.
Monte Carlo simulation for the determination of cumulative
distribution of fecal coliforms
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Bulking sludge phenomena in
wastewater treatment plants
• Aim: The research project investigated the consequences of sludge
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bulking in approximately 25 large wastewater treatment plants,
selected to cover the greater part of Greece
Procedure: Sludge and sewage samples were analyzed for
filamentous identification and sewage characteristics
several bench scale units were operated in order to investigate the
effect of critical parameters such as wastewater characteristics and
plant configuration
A population dynamics mathematical model and verified with the
aid of experimental data
According to the findings of the project useful practical suggestions
for the improvement of the operation of treatment plants in Greece
were formulated
Dominant filamentous bacteria in Greek WWTPs
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Optimization of flow pattern in
nutrient removal plants to prevent
bulking
Main objective:
• Development of control strategies to prevent
filamentous bulking in nutrient removal plants
{The Sanitary Engineering Laboratory of NTUA, worked in collaboration with
the other partners in all the aspects of the project}
Topics:
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Survey of existing nutrient removal WWTPs in Greece
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Wastewater characterization studies
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Pilot and laboratory scale studies on the effect of different modes
of operation on the growth of filamentous bacteria ( Microthrix
parvicella)
The main conclusions :
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Upgrading of wastewater treatment plants to nutrient removal in
many cases resulted in poorer settling properties of activated
sludge compared to conventional treatment plants without
nutrient removal
Poor settling properties( bulking): Normally caused: 1)by an
excessive growth of filamentous bacteria and in some cases 2)by
the surface chemistry of the activated sludge. Filamentous
bacteria hinder the agglomeration and settling of sludge
physically whereas the effect of surface chemistry is electrostatic
in nature
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30 identified bacteria may cause bulking. 4-5 were the ones most
commonly found in nutrient removal activated sludge systems
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Growth of filamentous bacteria: Depend on actual wastewater
composition and configuration and operational parameters of
process tanks
Use of selector systems: Successful in controlling bulking in
conventional treatment plants without nutrient removal.
Positive effect of selectors appeared to be reduced in nutrient
removal plants.
Microscopic identification of filamentous bacteria
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Author Affiliation: Environmental
Pollution Control Laboratory,
Department of Chemistry, Aristotle
University of Thessaloniki, Thessaloniki
GR-54124, Greece
• Summary:
Occurrence and the fate of heavy metals (Cd, Pb, Mn,
Cu, Zn, Fe and Ni) during the wastewater treatment
process were investigated in the wastewater
treatment plant (WTP) of the city of Thessaloniki,
northern Greece, operating in the activated sludge
mode.
Sampling Procedure:
Wastewater and
sludge samples
Influent
(raw
wastewater,
RW)
Effluent
(primary
sedimentation
effluent,
PSE)
Effluent
(secondary
sedimentation
effluent,
SSE)
Sludge
(primary sludge,
PS)
Activated
sludge
from
Recirculation
stream
(activated sludge,
AS)
Digested/
dewatered
sludge
(final sludge,
FS)
Research:
The distribution of metals between the aqueous and the
solid phase of wastewater was investigated
Results:
• Good exponential correlation was found between the metal partition
coefficient, logKp, and the suspended solids concentration
• Mass balance of heavy metals in the primary, secondary and the
whole treatment process showed good closures for all metal
species
• Relative distribution of individual heavy metals in treated effluent
and sludge streams indicated that Mn and Cu are primarily (>70%)
accumulated in the sludge, while 47-63% of Cd, Cr, Pb, Fe, Ni and
Zn remain in the treated effluent.
Flow chart of the Wastewater Treatment Plant of Thessaloniki
(QRW: 150 000 m3/d, QPS: 4500 m3/d, QAS: 150 000 m3/d,
QAS2: 3000 m3/d)