KAKOLANMÄKI WASTEWATER TREATMENT PLANT Presentation on Wastewater Treatment Processes at Kakolanmäki WWTP 30.1.2019 Jouko Tuomi PARTNER MUNICIPALITIES and OWNERSHIP
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KAKOLANMÄKI WASTEWATER TREATMENT PLANT Presentation on wastewater treatment processes at Kakolanmäki WWTP 30.1.2019 Jouko Tuomi PARTNER MUNICIPALITIES AND OWNERSHIP • Wholesale company owned by fourteen municipalities in Turku region in South-Western Finland • Turku Region Wastewater Ltd produces good quality and cost- effective wastewater treatment services to its owner municipalities • Subsidiary of Turku city SEWAGE NETWORK • WWTP treats 300.000 residents wastewater and industrial wastewater of the area, average inflow 90 000 m3/d • Over 2 000 km sewage network and 500 pumping stations • The sewage network is owned and operated by the municipalities. • Turku Region Wastewater Ltd maintains about 20 km of own sewage network OPERATING MODEL • Own personnel focuses on purifying wastewater • Own personnel managing, operating and developing the WWTP (13 employees) • Expertise in centralized regional wastewater treatment • Strategy: – the best possible cleaning results cost-effectively – optimizing the operation and taking into account energy efficiency, climate change and carbon footprint – preparing for exceptional situations – actively involving in research and development projects • Support services are outsourced • Sludge treatment (Gasum Oy) • Maintenance services (Caverion Suomi Oy) • Laboratory and reporting services (Lounais-Suomen vesi- ja ympäristötutkimus Oy) • Cleaning, maintenance of automation systems, financial management services... OUTLET • The processes of WWTP are located in the solid rock of Kakolanmäki hill in the middle of Turku city • The volume of the cave treatment plant is about 500 000 m3, which includes 125 000 m3 water capacity • Purified wastewater mixes with urban runoff before outlet point DAILY VOLUME OF WASTEWATER 6 Daily volume of wastewater 2011-2018 m3/d 2015 300 000 3 Qmax 275 000 m /d 2016 250 000 2017 200 000 2018 3 Qdim 144 000 m /d 150 000 100 000 50 000 0 1-Jan 14-Jul 29-Jul 1-Mar 16-Jan 31-Jan 14-Jun 29-Jun 12-Oct 27-Oct 15-Apr 30-Apr 15-Feb 12-Sep 27-Sep 11-Dec 26-Dec 13-Aug 28-Aug 11-Nov 26-Nov 16-Mar 31-Mar 15-May 30-May PROCESS FACILITIES AND PROCESS PLAN UNIT OPERATIONS • Pretreatment • Pumping station’s volume 500 m3 • Bar screening and step screening • Ferrous sulphate is aerated in the sand separation • Active sludge process • Primary clarifier works as a thickener • Aeration is divided into 7 sections; 2 anoxic, one anoxic/aerobic and 3 aerobic blocks. The final section is for degassing. • Polymer and ferrous sulphate are used as coagulants in the secondary clarifier • Tertiary treatment • 20 rapid sand filtration blocks, each has total of 1,5 meters of quartz and burnt clay • By-pass water treatment • Rapid chemical and mechanical treatment for rainwater and waters with harmful substances RESULTS OF PURIFICATION 9 AMOUNT OF 2014* 2015* 2016* 2017* 2018* WASTEWATER m3/d 81 700 88 600 77 100 84 400 74 100 m3/a 29 800 000 32 300 000 28 200 000 30 800 000 27 000 000 CONCENTRATION 2014* 2015* 2016* 2017* 2018* ENIVIRONMENTAL [mg/l] PERMIT* CODCr 38 36 38 38 35 ≤ 60 BOD7ATU 3,8 3,6 3,9 3,8 2,8 ≤ 10 Phosphorus 0,18 0,17 0,16 0,17 0,12 ≤ 0,3 Nitrogen 13 11 11 10 11 - Suspended solids 3,1 2,7 2,8 3,6 2,2 ≤ 15 CLEANING 2014* 2015* 2016* 2017* 2018* ENVIRONMENTAL EFFICIENCY PERMIT* [%] CODCr 94 94 95 95 96 ≥ 90 BOD7ATU 99 99 99 99 99 ≥ 95 Phosphorus 98 98 98 98 99 ≥ 95 Nitrogen 79 80 84 84 86 ≥ 75 Suspended solids 99 99 100 99 99 ≥ 95 * Including the sewage network overflows LOADS ON THE MARINE AREA tn/a Phosphorus load on the Turku marine area old Tarvasjoki WWTP 25 old Marttila WWTP old Oripää WWTP 20 old Pöytyä Riihikoski WWTP old Aura + Käyrä WWTPs old Lemu WWTP 15 old Vahto WWTP old Rymättylä WWTP 10 old Piikkiö WWTP old Merimasku WWTP old Paimio WWTP 5 old Kaarina WWTP 5,5 5,5 5,5 old Raisio WWTP 5,1 5,1 5,1 4,4 4,4 5,1 old Turku WWTP 0 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Kakolanmäki WWTP Phosphorus load on the Turku marine area has decreased approximately 73 percent or 14 t/a (2017 vs. 2006-2008) BOD7ATU-load on the Turku marine area has decreased approximately 67 percent or 240 t/a (2017 vs. 2006-2008) Nitrogen load on the Turku marine area has decreased approximately 45 percent or 260 t/a (2017 vs. 2006-2008) Suspended solids load on the Turku marine area has decreased approximately 84 % or 560 tn/a (2017 vs. 2006-2008) RECENT PROJECTS ODOR CONTROL • Ionization of incoming and exhaust air • Ionization of incoming air to remove odor in office spaces • Ionization of exhaust air to remove odor formed in sludge dewatering • Artificial rapids in sewage network • Hydrogen sulphide has caused major corrosion in company’s sewage network. Oxidation of wastewater before concrete sewage pipes reduces the amount of corrosive substances • Ventilation through active carbon filters • Prevention of hydrogen sulphide in sewage network with oxygen generator • Oxidation of wastewater reduces also the odor from sewage network on urban areas PROCESS OPTIMIZATION • Control of aeration with online ammonia measurement • Ion selective electrode is an accurate way to measure the level of ammonium ions in aeration tank and to use that information to adjust the tank’s dissolved oxygen concentration • Procurement of sewage sludge drying equipment • New centrifuges for dewatering of sludge to reduce transportation costs and save energy • Trial tests were performed on site with every provider’s machine • New higher capacity polymer station and pumps • Permanent magnet motors for aeration compressors and ventilation machines • Lower energy consumption and lower maintenance costs THANK YOU! www.turunseudunpuhdistamo.fi.