Case Helsinki: Composting Helsinki Region Environmental Services Authority Janne Nipuli, Daugavpils 30.10.2012 HSY/Janne Nipuli 1
HSY HSY began its operations on 1 January 2010. HSY provides waste and water management services for the more than one million residents of the Helsinki metropolitan area. In addition, it produces information on, for example, air quality, the climate and housing. 30.10.2012 HSY/Janne Nipuli 2
HSY HSY's nearly 800 employees work efficiently to make the Helsinki area an environmentally responsible metropolitan area and to ensure that acting in an environmentally friendly fashion is made easy to all residents of the region. HSY was formed by consolidating the waterworks of the Helsinki region as well as the Helsinki Metropolitan Area Council's waste management, and regional and environmental information services. 30.10.2012 HSY/Janne Nipuli 3
HSY works in favour of the environment HSY provides high-quality drinking water for the more than one million residents of the Helsinki metropolitan area. HSY efficiently purifies the wastewater produced by the city residents and local industry to protect the Baltic Sea. At HSY's wastewater treatment plants, the organic matter contained by the sludge is digested and the resulting biogas is used to produce electricity and heat for the plants. 30.10.2012 HSY/Janne Nipuli 4
HSY works in favour of the environment The bio-sludge generated by the wastewater treatment plants is further treated into soil on specialised composting fields. The waste heat of the treated wastewater is utilised in the production of district heating at the Katri Vala heat pump plant. Landfill gas is collected and utilised to produce electricity and heat. 30.10.2012 HSY/Janne Nipuli 5
HSY works in favour of the environment We provide waste management services for residential properties and the public administration in the metropolitan area. We also collect recyclable and hazardous waste. We provide up-to-date information on the sorting, reduction and prevention of waste. We monitor air quality at 11 monitoring stations across the metropolitan area. 30.10.2012 HSY/Janne Nipuli 6
Sludge processing operations Viikinmäki WWTP (PE 780 000) and Suomenoja WWTP (PE 250 000) produce approximately 80 000 tons of sludge with SS concentration of 30 % Both treatment plants have a mesophilic digestion process (ca. 20 days) and a centrifuge sludge dewatering process 30.10.2012 HSY/Janne Nipuli 7
Sludge processing operations Sludge from Suomenoja WWTP (appr. 20 000 tons/a) is processed in Kekkilä Oy s composting site Sludge from Viikinmäki WWTP (appr. 60 000 tons/a) is processed in HSY s own composting site The machine work of Metsäpirtti composting site is outsourced 30.10.2012 HSY/Janne Nipuli 8
Composting site of Metsäpirtti Founded 1994, area is about 17 ha Waterproof rubber-bitumen asphalt surface Runoff water are collected and leaded to Viikinmäki WWTP 30.10.2012 HSY/Janne Nipuli 9
Määrä (m3/a) Composted soil sale rate Metsäpirtin myyntimäärä 300 000 250 000 200 000 150 000 100 000 50 000 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 kompostimulta maanparannuskomposti 30.10.2012 HSY/Janne Nipuli 10
Composting process lawn soil Sludge 1 ton Sedge peat 1,25 m 3 1. Mixing Stack composting mechanical mixing composting period ½ year 2. Mixing 1 ton composted sludge 0,6 ton sand 15 kg biotite Recirculatable screenings Screening screen size 20 mm Screening refuse METSÄPIRTTI LAWN SOIL 30.10.2012 HSY/Janne Nipuli 11
Composting process Soil betterment compost Sludge 1 ton Sedge peat 1,25 m 3 1. Mixing Stack composting mechanical mixing 3 times composting period minimum ½ year METSÄPIRTTI SOIL BETTERMENT COMPOST 30.10.2012 HSY/Janne Nipuli 12
Mixing Station Pre-mixer Input material silos Capacity: about 50 ton sludge per hour Drum-mixer, 14m x 2m 30.10.2012 HSY/Janne Nipuli 13
Compost turning (aeration) ALLU Windrow Turner ALLU screener crusher bucket for a wheel loader 30.10.2012 HSY/Janne Nipuli 14
Soil mixing station Control cabin Input silos Mixer Star screen, 100 m3/h 30.10.2012 HSY/Janne Nipuli 15
Positive/negative about stack composting + Flexible, reliable method + Only simple machines needed - Long composting time (winter time) - Needs much effort for quality monitoring 30.10.2012 HSY/Janne Nipuli 16
Quality All kind of use is allowed High standard raw materials => high quality product High level self-monitoring Production quality is spot checked by EVIRA 30.10.2012 HSY/Janne Nipuli 17
Heavy metals in sludge VIIKINMÄKI WWTP SLUDGE ANALYSES 2011 min. average max. ph 7,8 8,1 8,3 TS % 27 29 31 Ignition residue % TS 46 48 52 Nitrogen g/kgts 29 30 31 Phosphorus g/kgts 29 34 39 Potassium g/kgts 1,2 1,5 2,0 Calsium g/kgts 25 32 38 Aluminum g/kgts 6 7 9 Magnesium g/kgts 2,6 3,1 3,4 Iron g/kgts 97 125 138 Mercury mg/kgts 0,4 0,5 0,8 Cadmium mg/kgts 0,6 0,7 1,0 Cobalt mg/kgts 7 10 13 Chrome mg/kgts 33 44 54 Copper mg/kgts 240 310 340 Lead mg/kgts 14 19 29 Manganese mg/kgts 240 270 300 Nickel mg/kgts 15 20 24 Zinc mg/kgts 450 520 630 Arsenic mg/kgts 4,0 5,0 7,0 30.10.2012 HSY/Janne Nipuli 18
The highest permitted heavy metal concentrations of farming sludge and sludge mixture comparing to the concentrations of Metsäpirtti lawn soil Limit values* mg/kg of solid matter Mean values of analytical data 1.1.-31.7.2010 Lawn soil concentration s percentace of the limit value Arsenic 25 4 16,0% Cadmium 1,5 0,2 13,3% Chrome 300 22 7,3% Copper 600 79 13,1% Mercury 1 0,1 10,0% Nickel 100 9 9,0% Lead 100 9 9,0% * Regulation of the Council of State (282/94 The use of wastewater treatment plant sludge in farming) 30.10.2012 HSY/Janne Nipuli 19
Expenses and prices 2011 Operation costs 4,3 Milj. Personnel 0,3 M (7 %) Material costs 1,5 M (35 %) Outsourced services 2,5 M (58 %) Other 0,02 M (0,5 %) Income 1,7 Milj. Unit cost ca. 43 /sludge ton Composted soil price 22-30 /m3 (including VAT and transportation) Price depends on the load size and delivery place 30.10.2012 HSY/Janne Nipuli 20
Conclusion It s about responsible waste recycling Recycling 400-600 tons phosphorus and nitrogen Carbon back to the ground Continuation: 80 000 tons per year to recycle High standard products Marketing 30.10.2012 HSY/Janne Nipuli 21
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