Geological Survey of Finland
GTK’s role in WaterPro concerns especially the estimation and management of nitrogen runoffs from aggregate and dimension stone quarries. GTK offers its expertise in gaining Good Practices in this field and will organise pilot phase activities in two sites in Eastern Finland (Juuka, soapstone quarry and Lapinlahti, stone quarry). GTK is a leading European organisation that deals with the environmental issues of the minerals sector with almost twenty professionals dedicated to the environmental issues of mining and quarrying. GTK has studied WaterPRo related issues in the Green Mining funded MINIMAn Project (Management of nitrogen emissions from mines and quarries) and studies passive treatment methods in several projects, including the ERA-MIN funded SUSMIN Project. GTK will take actively part in Communication as well as knowledge transfer platform by utilizing its own wide communication networks, both regionally and transnationally.
WaterPro – summary of GTKʾs pilot studies
The pilot studies that Geological Survey of Finland (GTK) focuses In WaterPro project, are focused to the estimation and management of nitrogen runoffs from aggregate and dimension stone quarries. In addition GTK offers its expertise together with Luleå University of Technology (LUT) to define mining sectors’ Good Practices that are used to control the nutrient runoff from quarries and mines. GTK’s aim is to create useful instructions to the use of mineral based sorbents (vermiculite and zeolite) in the control of the pulse type nitrogen emissions that are caused by blasting events in quarry and mine sites and to evaluate the possibility of the use of the remnant material as a fertilizer. This is achieved with reliable screening of the capabilities of the sorbent materials.
During autumn 2016 pulse type nitrogen emissions originating from explosives were monitored at GTK’s pilot sites in Eastern Finland (Juuka soapstone quarry and Lapinlahti anorthosite quarry). This was done to find out the general levels of different nitrogen species after blasting events. Based on a literature review and the results of this monitoring program, the screening of the capabilities of the sorbents started in laboratory during summer 2017. In these tests different amount of filter materials (4g, 8g, 16g and 32g) were mixed with nitrogen contaminated water for 15 min, 1h, 2.5 h and 24h. In addition the effect of different pH and temperature conditions was studied.
Fig 1. Mixing different amounts of filter materials in nitrogen rich water in different pH conditions
Preliminary results showed that both vermiculite and zeolite removed ammonium effectively from waste water and the changes in temperature and pH didn’t have strong effect to the sorption capacity. Detailed mineralogy studies revealed multiple mineral phases in the filter materials. This may affect to the ammonium removal capacity due different physical properties of different mineral phases. Geochemistry results showed that unwanted sulfate and sodium leached from zeolite to water. Based on these preliminary results vermiculite seems more suitable filter material for nitrogen rich waste waters.
Fig 2. SEM figure of vermiculite structure
Final phase of GTK’s pilot study starts in 2018. The long-term ammonium removing properties of vermiculite is studied during the summer 2018 to determine the capacity and applicability of vermiculite in the control of pulse type nitrogen emissions in vulnerable sub-arctic and arctic conditions. This will bring more possibilities to protect oligotrophic environments where even small amount of excess nitrogen can make a big impact to the ecosystem of the water body.
You can access GTK’s WaterPro Flyer Here.