Hajdow Sewage Treatment Plant
Azra Gackic
Federal Ministry of Physical Planning and Environment
Bosnia and Herzegovina
As part of a BERCEN study tour to Poland, we visited the Municipal Water Supply and
Sewage Co. Ltd. in Lublin, a utility that pays special attention to environmental protection.
The Hajdow wastewater treatement plant, which opened in 1992, is one of the largest
wastewater treatment plants in Poland. The plant is undergoing modernisation in order to
fulfil the standards and legal requirements of international obligations related to the
elimination of hazards and the improvement of ecological safety. The upgrading also aims to
minimise the impact of pollution on human health, meet a responsibility to future generations
and improve the environmental conditions expected by society.
Changing economic and legal conditions as well as social expectations have forced the
company to consider not only the financial and operational aspects of the plant's
management, but also how it contributes to sustainable development. Company policy also
aims to ensure the best possible living conditions for current and future generations, preserve
the unique value of the natural environment and enable people to use its resources.
The certificates obtained by the company confirm its compatibility with the international
standards of ISO 9001, ISO 14001, PN-N 18001, and PN-EN ISO/IEC 17025. These
qualifications prove that the company is searching for organisational, financial and
tehnological solutions that ensure proper environmental protection of water. At the same time
the company strives to fill its basic mission of ensuring enough water for residents, industry,
farms and other users.
Our age can be called the age of sewage treatment technology, and this is due in large part to
the biological method of treatment. A characteristic of the technologies implemented at
Hajdow is their high degree of innovativeness, which has produced magnificent results in
reducing pollution. The modern technologies applied play a significant role in the protection
of the water, air and land. Without these innovations, it would not have been possible to
make such progress in solving problems related to environmental pollution.
Hermetic sealing of the wastewater treatment plant
The biofilter installed in the wastewater treatment plant for the first area grouping
significantly limits noxious odours. The measuring-tubes pipes chamber, the emergency
dumping chamber, the sewage pumping chamber and the grid chamber have been
hermetically sealed, and the malodorous gases therein are directed by a special ventilation
system to the biofilter, where they are cleared of unpleasant odours. The process of air
purification is based on the pumping of air through a filter stuffed with the biomass.
When air comes into contact with the biomass, the foul gases are decomposed by microorganisms. The purified air escapes through the open, upper biofilter surface into the
atmosphere.
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In line with prior estimates, preliminary studies showed the process reduced concentrations
of noxious odours by 90 percent.
Technical data:
 volume of air purified: 5,300 m3/h
 biofilter surface: 50 m2
 size (length x width x height): 10m x 2.5m x 1.7m)
 bio-mass volume: 66 m3
At present, construction is going forward on the second bio-filter installation for the hermetic
thickeners of raw sludge.
Reduction of biogenic compounds
The plant is undergoing modernisation in order to adapt the new technology to domestic and
EU requirements and standards. The modernisation will allow greater amounts of nitrogen
and phosphorus compounds in the sewage to be treated. The investment is being carried out
in stages. At the moment, part of the sewage is treated by means of the new technology based
on the modified BARDENPHO system.
To achieve a reduction in biogenic compounds, two primary settling tanks were modernised
in the sewage treatment plant; new pipelines taking sewage to the primary settling tanks were
laid; equipment enabling the precipitation of chemical phosphorus was installed; and two
blocks of aeration chambers were re-constructed and modernised. The aeration chambers
needed to be adjusted for the nitrification and de-nitrification processes. A mechanical station
for thickening the surplus sludge was also constructed.
Station for mechanical thickening of surplus sludge
In the biological processes of sewage treatment, surplus sludge is generated. It is then
subjected to methane fermentation in separate fermentation chambers. It is biologically active
sludge with very little dry mass and a high concentration of organic compounds. This type of
sludge is very difficult to dehydrate.
As a result of the application of the new sewage treatment technology, the amount of surplus
sludge is increased, which in turn has made it necessary to construct a mechanical station for
thickening any surplus sludge. To do this, the part of the building housing the air blowers has
been divided, and two band thickeners were installed for the pulping and dosing of
flocculants — a chemical thickening agent.
Technical specifications of the band thickeners:
 Efficiency of a single unit: up to 120 m3/h
 Dry mass content in the sludge at input: about 0.5 percent
 Dry mass content in the sludge at output: about 6 percent
 Flocculants needed: about 3-5 g/kg of dry mass
The modernisation project assumes the construction of an intermediate sewage pumping
station, modernisation of re-circulating sludge pumping settling tanks; conversion of the
three primary settlers into anaerobic chambers with designated pre-denitrification zones;
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modernisation of a further three blocks of aeration chambers; and modernisation of
secondary clarifiers.
A further extension of the computer monitoring and technological process controlling the
system has also been foreseen. The system collects data from the individual areas in the
modernised part of the wastewater treatment plant, while the programmes installed provide
for automatic control of the technological process. Data transmission takes place by means of
optical fibres.
Funding
The company has undertaken enormous organisational and financial efforts for this
modernisation. During the first stage (i.e. up to June 30, 2002) the total cost incurred for the
reduction of biogenic compounds was PLN 21,745,000.
The funds were obtained from the following sources:
 National Fund for Environmental Protection and Water Management: a loan of PLN
4,350,000
 Voivodship Fund for Environmental Protection and Water Management: a loan of
PLN 3,000,000
 municipal budget of the city of Lublin: a subsidy of PLN 4,359,000
 Danish Agency for the Protection of the Environment: a subsidy of PLN 1,819,000
 company’s own means: PLN 8,217,000
In the second stage of modernisation, the construction of the installation for the thermal
drying of fermented sludge was included in the project. The costs assumed for biogenic
substances reduction and sludge drying were PLN 70,591,000.
On September 20, 2002, after many years of endeavour, financial memorandum No.
2002/PL/16/PE/029 was signed. In the memorandum, the European Union granted the
Muncipal Water Supply and Sewage Company Co. Ltd. a subsidy from the ISPA fund of
PLN 38.76 million, or 60 percent of the costs assumed for those tasks qualifying for subsidy.
Effects of the biological elements of the modernisation
Reduction of biogenic compounds
At present, part of the sewage is already treated by means of modern technology.
Modernisation of part of the wastewater treatment plant has produced measurable reductions
in the pollutant concentrations in the sewage treated. The mean concentration levels of the
pollutants in the treated sewage before modernisation, and the effects obtained after the
completion of the first stage of the project, are presented in the table below.
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Parameters of sewage treated in the Hajdow wastewater plant before and after partial
modernisation
Parameter
BOD
COD
Suspended
solids
Total N
Total P
Acc. to EU
directive
[mg/dm3]
25
125
35
Before modernisation IX-X 1999
[mg/dm3]
24
50
13
Reduction [%]
92
92
95
After partial modernisation
IX-X 2002
[mg/dm3]
Reduction [%]
9
97
43
94
11
97
10 or
reduction
70-80%
1.0 or
reduction
min. 80%
40
37
18.4
74
8.5
12
4.8
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Poland is one of the first countries in Europe to elaborate and accept an official national
ecological policy. The policy states that one of the main directions of environmental
activities should be the rationalisation of the usage of natural resources. This work will
involve, among other things, the return of treated water to the catchment system and reducing
the permitted levels of pollutants in water.
The legal basis for this endeavour, with a view to the adaptation of the Polish legal system to
European Union directives, was included in legislation adopted on July 18, 2001 on water
regulations. It was also included in the instruction of the Minister of the Environment dated
November 29, 2002 on the conditions to be fulfilled when releasing sewage into water or
onto land.
The modernisation of the Lublin-Hajdow wastewater treatment plant carried out by the
Municipal Water Supply and Sewage Company fulfils the requirement of communal city
treatment as specified in the above legislation. It also realises the goals and limitations on the
use of water resulting from the natural prerequisites and requirements for water and
environmental protection included in the Lublin Voivodship document, “Conditions for the
use of the waters of the Wieprz Basian.” The latter document also covers the Bystrzyca River
basin, an outlet for treated sewage from the city of Lublin.
The final stage of the comprehensive modernisation of the plant achieved reductions in
eutrophic nitrogen and phosphorus compounds. This confirmed that the technicaltechnological assumptions of the project were correct and would achieve the project goal, i.e.
third-class purity of Bystrzyca River below the sewage discharge point and a decrease of
some 80 percent in eutrophic discharge from Lublin Voivodship into the Wieprz River to the
middle part of the Vistula River, and finally to the Baltic Sea.
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