Impact of utilised bottom ash

Transcription

1 Impact of utilised bottom ash Raul Grönholm, MSc, Sysav Jan Hartlén, PhD, JH Geoconsulting 24 januari

2 Agenda SYSAV BOTTOM ASH FROM WASTE INCINERATION USE OF BOTTOM ASH MONITORING AND ESTIMATION OF ENVIROMENTAL IMPACT

3 The Sysav group handled tonnes of waste in 2010 Household waste Bulky waste Industrial waste Construction and demolition waste Health care waste Hazardous waste WEEE, Waste Electric and Electronic Equipment with a combination of methods 97% is recycled as material or energy / bild 3

4 Sysav Bottom ash treatment 20% of the combustible waste becomes BA tonnes Pre-treatment Drying Treatment The BA is sieved. Scrap and NF-metal is removed Post treatment It is stored for 6 months The stockpiles are documented 24 januari 2012 / bild 4

5 Quality control Storage for 6 months Sampling from the stockpile Sampling according to standard method Nordtest NT Envir4 Comparison to quality control parameters avalability of heavy metals, ph organic matter (loss of ignition) Quality control limit values ph <9 Cu <3000 mg/kg LoI <5% Ni <200 mg/kg Cd <9 mg/kg Pb <1000 mg/kg Cr <4 mg/kg Zn <4000 mg/kg 24 januari 2012 / bild 5

6 Before use BA Permit from local environmental authorities Risk assessment BA characteristics and quality localization Construction design groundwater impact monitoring program Annual report to authorities 24 januari 2012 / bild 6

7 BA used tonnes Soil remediation t Parking lot t Factory area t Parking lot t Recovery area t Factory area t Recycling center t Parking lot t Factory area t Factory area t Recycling center t Parking lot t Landfill cover t 24 januari 2012 / bild 7

8 Monitoring Enviromental impact At least four groundwater wells, one in each direction Samples taken twice per year as long as the control program is open, once per year after the control program is closed. Database with samples from Evaluation for each well on Zero value, before applying BA Mean and median value for the entire monitoring period Results from the latest measurement Plotting the results Comparisons to look for an increase or decrease of a substance in the monitoring wells Trying to find patterns Looking for a highest value Studying variation Sjölunda Chromium 24 januari 2012 / bild 8

9 Evaluated enviromental impact from BA No increase detected ph, Arsenic, Cadmium, Calcium, Copper, Chromium, Iron, Lead, Mercury, Magnesium, Manganese, Nickel, Vanadium Marginal increase detected Alkalinity, Aluminum, Potassium, Cobalt, Sodium, Zink Significant increase detected Chloride (factor ) The amount increases significaly. The variation over the monitoring period is not obvious. Local enviromental impact can not be ruled out. External sources of chloride may also contribute. Sulphate (factor 10-50) Mostly an initial impact. A tendency to decrease with time can be detected Chloride Sulphate 24 januari 2012 / bild 9

10 Water flow New well Monitoring well Topsoil Soil Bottom ash Upper Moraine Filter Aquifer 1 Sediments Moraine of Barrier 1 24 januari 2012 / bild 10

11 General assessment The levels may increase initially for some substances but most of the time it stabilizes or decreases. The following substances will be followed up: Sodium, Chloride and Sulphate. Their impact will also be studied below the asphalt surface at Bunkeflo recycling center. The impact from the exploitation of the areas as new drainage, traffic and ice desalting may have considerable influence on e.g. the chloride content New wells need to be drilled about 50 meters away to ensure that Chlorides and Sulphates has not spread. 24 januari 2012 / bild 11

12 Summary BA can technically be used as an unbound road base construction material. BA will give a minor impact on groundwater aquifers. Quality control is important. BA shall not be used in water catchment areas. Further attention shall be on the effect of Chloride and Sulphate leaching and external influence. 24 januari 2012 / bild 12

13 Thank you very much for your attention Questions?? 24 januari 2012 / bild 13