Capacity extension of the wastewater treatment plant and the construction of the connecting sludge treatment structures in the town of Keszthely

Transcription

1 Capacity extension of the wastewater treatment plant and the construction of the connecting sludge treatment structures in the town of Keszthely Adrian Kiss Hungarian Water Technology Corporation (HWTC) Pristina, Kosovo, 1-3 November 2017

2 Table of Content 1. Location of the project and background 2. The antecedents of wastewater treatment main deficiencies 3. The goals of the development project 4. New facilities and construction work 5. Biogas utilization 6. Outcomes and achievements

3 Location of the project and background

4 Transdanubian Regional Waterworks Plc (DRV Zrt.) Provision of water supply services in 400 settlements for consumers Wastewater treatment services in 200 settlements for consumers Regional water utility company (largest shareholder is the state)

5 inhabitants Location of the project: Town of Keszthely Located on the western shore of Lake Balaton Important cultural, educational and economic hub in the region Keszthely and the surrounding area is a preferred holiday destination More than 1.5 million tourists at Lake Balaton in a year 10,5% of total GDP comes from tourism, Lake Balaton is the second most visited region in the country after Budapest

6 Location of the project: Town of Keszthely Lake Balaton s environmental protection is an important topic in Hungary, due to is rich ecosystem and touristical attractions

7 Background Population of the agglomeration: Pers. Previous capacity PE Planned capacity: PE Unique features: The load doubbles during the summer season The percentage of rainwater is high

8 The antecedents of wastewater treatment main deficiencies

9 The antecedents of wastewater treatment main deficiencies Lack of the mechanical cleaning capacity and it was in bad technical conditions

10 The antecedents of wastewater treatment main deficiencies The design and capacity of the biological treatment was inconvenient in order to be able to comply with the new requirement parameters.

11 The antecedents of wastewater treatment main deficiencies The desilting area was inadequate and the existing lime clarifier could not be used.

12 The antecedents of wastewater treatment main deficiencies Disinfection was only possible with a large chlorine residual.

13 The antecedents of wastewater treatment main deficiencies The energy recovery from sewage sludge was not available.

14 The antecedents of wastewater treatment main deficiencies Inadequate measurement possibilities, the level of automatization was low Air inlet was insufficient, its fine tuning was not available Iron-salt feeding needed some improvement

15 The goals of the development project

16 The goals of the development projects: Nutrient removal to be carried by the pretreatment of raw wastewater. Developing the biological treatment. Treatment of the various sludges and leachate. Biogas utilization by a gas engine for electricity production. Construction of a small bridge and fence. Road construction and paving work, landscaping. As a result of the reconstruction work, the biological treatment capacity to be extended to m3/d, which is equal to PE.

17 The goals of the development projects: During the development project, the structures and technical equipment of the biological treatment process were reconstructed, which resulted in the decrease of the total suspended solids, total nitrogen and phosphorous quantities. Parameters Planned effluent values (mg/l) Limit value (mg/l) KOIKr (mg O2/l) BOI5 (mg O2/l) Total suspended solids mg/l NH4-N (mg N/l) Total nitrogen mg N/l (V.1. - XI. 15) 20 (XI IV. 15) Total phosphor mg/l

18 New facilities and construction work

19 Deseign of the construction: Companies that carried out the construction work: Keszthely A-SZ konzorcium Member of the consortium: Leader of the consortium:

20 New facilities: Mechanical cleaning: Construction of a new screen filter in a closed building, installation of 2 parallel, mechanically-cleaned screens of 3 mm rod distance with 1250 m3/hour/unit capacity Refurbishment of the pumps engine house and central pump, installation of 5 pumps, m3/day Installation of 2 sand washing machines, m3/day Mechanical refurbishment of a raw sewage measuring shaft with the installation of 2 induction flow meters Construction and mechanical development of a 425 m3 pre-settlement structure with a connected direction shaft and settled waste water quantity measuring shaft

21 Biological cleaning: New facilities: Reconstruction of the existing 792 m3 anerobic and m3 anoxic basins Reconstruction of the existing 10,13 m3 canal basins Reconstruction of the existing 3 x 2,26 m2 unified structures Architectural and mechanical refurbishment of the 2 x 1,04 m2 Dorrtype post-settlement structures Construction of a new blast engine house with 4+1 air blower and Nm3/d/unit capacity

22 The recovery of biogas Facilities: Biological cleaning: Reconstruction of the old blast-engine house with 3+1 air blowers and Nm3/d/unit capacity Construction of a new UV disinfection facility Refurbishment of the iron-salt storage and feeding building

23 The recovery of biogas

24 Pre sedimentation unit

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26 Wall construction

27 Prefabricated Central Seed

28 Pre-sedimentation unit

29 Digesting towers

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34 Biogaz utilization

35 Biogas utilization: During the expansion of the technology line of the wastewater treatment plant a biogas production facility was also constructed which utilizes the generated sewage sludge in an environmentally friendly way. From the newly constructed pre-sedimentation unit (pre-settling basin) the so called primary sludge is transported to the digester towers of the biogas plant. The so called secondary sludge (excess sludge) is also transported to the towers, which mainly contains a mass of bacteria.

36 Biogas utilization: From the sludge, biogas is generated in the digester towers, which is used for the heating of the tower and for electricity production by a gas engine. The generated energy covers approximatively 1/3 of the total energy needs of the plant. The digested sludge which is coming out from the towers is stabilized, and can be utilized for agricultural purposes without any environmentally harmful effects.

37 Generated biogas during winter: Specific energy content of the biogas 6,3 kwh/m3 Energy content during 100%-os capacity use kwh/d Energy availability 85 % Standby energy at CHP 1109 kwh/m3 Actual heat capacity during full-load 407 %

38 Outcomes and achievements

39 Outcomes of the project: Technological development New sludge treatment facility with activated sludge treatment technology cascade formed, parallel functioning treatment lines Primary sedimentation Biological nitrogen and phosphorous removal Fine bubble deep air blowing Chemical phosphorus precipitation Optimization of the wastewater treatment efficiency Reuse of the produced biogas, whereby fulfilling a great percentage of the heat and energy needs of the plant

40 Outcomes of the project: The prime contractor took care of the following tasks during the project implementation process: Authorization procedures Civil engineering, water and utility construction work Architectural, building and water engineering work Electrical, remote and process control and operational test work

41 Outcomes of the project: Net value of the investment: 8.2 million EUR The following results were achieved by development project: Pollution decrease in surface waters and future water reserves (Lake Balaton), improvment of water quality Protection of human health and the flora & fauna Increase in the number of modern wastewater treatment systems that are in full compliance with EU regulations Construction of modern, environmentally friendly and sustainable sewage sludge treatment facilities being in full compliance with EU regulations Decrease in the operational costs of the WWTP and sludge is reused for energy purposes with anaerobe digestion.

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