Assessing the environmental impacts of landfill mining activities

Transcription

1 SMART data collection and integration platform to enhance availability and accessibility of data and information in the EU territory on SecoNDary Raw Materials Assessing the environmental impacts of landfill mining activities Csaba Vér, Dávid Somfai University of Pécs This project has received funding from the European Union s Horizon 2020 research and innovation programme under Grant Agreement No

2 Contents 1. Environmental impacts of landfill mining activities (on soil, water, air) 2. Environmental issues of pilot landfills and extractive waste facilities 3. Three examples of technology emissions in future landfill mining scenarios

3 The environmental impacts of landfill mining activities In Smart Ground project, the environmental impacts on soil, air and water, as well as human health connected issues were analyzed in the investigated pilot sites (EW and MSW landfills). Detailed analysis has been developed to identify environmental, human health and safety issues linked to landfills and other facilities. In particular, samples of soil, water and air were investigated to identify, classify and quantify the content of potentially harmful minerals and other inorganic compounds (e.g. asbestos, quartz, synthetic vitreous fibers).

4 Impact on air In the context of the SMART GROUND project, natural inorganic fibers and particles may come from the excavation of mining dumps or municipal solid waste (MSW), aiming the recovery of raw materials. Some of them could be harmful to human health when respired in high doses (e.g. asbestos fibers, quartz dusts), their possible release and presence in air, have to be specifically evaluated before beginning the recovery of raw materials. Numerous studies have highlighted associations between airborne particulate matter (PM) and adverse health effects, including morbidity and mortality, due to respiratory and cardiovascular diseases. The composition of inorganic PM is complex (consisting of crustal elements, trace metals, and ionic species) and some of the particles are of greater public health concern than others.

5 Impact on water The impacts on water systems connected to mining activities depend on the ore type, metal being extracted, exploitation method, ore processing, pollution control efforts, geochemical and hydro-geochemical conditions of water and surroundings. In the European Union, standards to protect groundwater were implemented and required, e.g. some landfills to use plastic liners and collect and treat leachate (the water solution that results after water passes through a landfill). However, because of many disposal sites are old and thus exempted from these rules, the main impact on water resources remains leachate formation if not well controlled. Figure 1.: Conceptual scheme of groundwater circulation in an abandoned metal extraction site Figure 2.: Simplified scheme of groundwater and surface water contamination from a waste disposal site

6 Impact on soil Mining and smelting operations are often the most important local sources of environmental contamination by metals and metalloids. Metal contamination has been documented in many mining-smelting areas of the world, but little seems to have been done so far to remediate the contaminated sites. The presence of heavy metals in soils is a matter of concern because they are well known for their toxicity to humans and their persistence in the environment. The extraction of metals for various human purposes has had a considerable impact on the environment in terms of pollution, constituting the second most important source of heavy metal contamination of soil after sewage sludge.

7 Environmental impact on air (Metsäsairila MSW landfill) Sampling well ID Compound Concentration (µg/m 3 ) DH 1 Hexane 520 (EU-LCI value 4300) Benzene 22 (-) Toluene 150 (2900) Ethylbenzene 33 (850) p/m-xylene 110 (500) DH 3 Hexane 490 Benzene 31 Toluene 180 Ethylbenzene 360 p/m-xylene 1200 DH 6 Hexane 750 Benzene 180 Landfill gases have negative effects on the environment and public health, such as explosive potential of methane and toxic impacts of VOC s and H 2 S. Table 1. shows measured VOC s in three measuring points. Methane gas, siloxanes and H 2 S released to air during landfill mining activity should not be neglected either. Toluene 900 Ethylbenzene 540 p/m-xylene 1400 Table 1 : Amounts of some measured VOC s in three sampling points in Metsäsairila MSW landfill

8 Environmental impact on air (Campello Monti EW facility) Figure 3 : Particles in PM2.5 in the samples CM_02_01 of Campello Monti The most abundant inorganic particles (in PM2.5) detected in sample CM_02_01 (Figure 3.) belong to pyroxene group (59%, they may be identified as enstatite and diopside). The remaining species are: amphiboles (16%, they may be identified as hornblende, tremolite-actinolite, and anthophyllite (probable) phyllosilicates (9%), Fe oxide/hydroxide (7%), and others (9%)

9 Environmental impact on water (Metsäsairila MSW landfill) Sample DH1 <20 mm DH2a <20 mm DH3 <20 mm DH6 <20 mm DH7 < 20 mm EU-landfill for non-hazardous waste (2003/33/EC) Eluate ph 8,3 8,3 8,6 8,1 8,1 >6 Leached components, mg/kg dry matter (L/S 10) As <0.10 < <0.10 < Ba Cd <0.02 <0.02 <0.02 <0.02 < Cr 0.02 < <0.02 < Cu < Hg <0.10 <0.10 <0.10 <0.10 < Mo Ni Pb <0.10 <0.10 <0.10 <0.10 < Sb <0.20 <0.20 <0.20 <0.20 < Se <0.30 <0.30 <0.30 <0.30 < Zn Cl F SO DOC Table 2. : Leaching test (EN ) results for fine fraction samples <20 mm from Metsäsairila landfill. Table 2. shows the results of leaching tests for the fine fraction samples in Metsäsairila landfill. In comparison, leaching criteria for EU-landfill for non-hazardous waste (2003/33/EC) are shown. All the leaching criteria for EU-landfill for non-hazardous waste were fulfilled. There are many factors affecting the quality of leachates, i.e. age, precipitation, seasonal weather variation, waste type and composition. In particular, the composition of landfill leachates varies greatly depending on the age of the landfill.

10 Environmental impact on water (Campello Monti EW facility) Table 3. : Chemical analyses of SW samples of Campello Monti The results of chemical analyses (see in Table 3.) on surface water samples were compared with the guidelines laid down by European (EU Directive 2008/105/CE) and national legislation on water pollution (Italian legislative decree 152/06). Water samples with high nickel concentrations (up to 512 μg/l) are located in the creek that crosses the mine area. Free cyanides were never detected.

11 Environmental impact on soil (Metsäsairila MSW landfill) According to table 4., the fine fraction (<20 mm) samples contained primarily compounds of Ba, Cr, Cu, Zn and Pb. Amounts of Ag, Au and In were rather low, as expected. Table 4.: Chemcial parameters reults from Metsäsairila Landfill

12 Environmental impact on soil (Campello Monti EW facility) Sample Fe Mn Cd Co Cu Cr Ni Pb Zn g/kg mg/kg CM_01_S nd CM_02_S nd CM_03_S nd CM_04_S nd CM_05_S nd CM_06_S nd CM_07_S nd CM_08_S nd CM_09_S nd CM_10_S nd CM_11_S nd CM_12_S nd CM_13_S nd CM_14_S nd CM_15_S nd CM_16_S nd CM_17_S nd CM_18_S nd Pseudo-total content of metals in Campello Monti soils samples. (nd= not detected). Values above the legislative limits are in bold Table 5.: Pseudo-total content of metals in Campello Monti soil samples The soils are heavily contaminated by heavy metals (see Table 5.). In Campello Monti they are especially contaminated by Ni, Cr and Cu. Most Co values are greater than the legislation level (20 mg/kg) and one sample near the tailings (CM_15_S) is above the upper limit (250).

13 Pátka tailings emissions of a future mineral processing plant At the Fluorite flotation tailings at Pátka village (Hungary), a future mineral processing plant would treat about 16,200 tons of tailings material during its lifespan, producing 650 tons of Fluorite preconcentrate. The use of diesel fuel and 50,500 MWh electricity results in the emission values seen in table 6. Air pollution kg SO 2 5,057 CO 75,855 CO 2 4,197,310 Input kg Output kg Fluorspar flotation tailing 16,200,000 Preconcentrate 650,000 Tailings 15,550,000 Table 7.: Pátka mineral processing tailings input and output flows CH NO x 166,881 Dust 5,057 Table 6.: Pátka - emissions

14 Rudabánya tailings emissions of a future mineral processing plant At the iron ore processing plant s tailings at Rudabánya (Hungary), a future mineral processing plant would treat about 4 million tons of tailings material during its lifespan, producing 800 thousand tons of magnetic and 1,2 million tons of non magnetic products. The use of diesel fuel and 76,600 MWh electricity results in the emission values seen in table 8. Air pollution kg Input t Output t SO 2 11,660 CO 174,900 CO 2 9,677,800 Iron ore processing tailings 4,000,000 Coarse product 2,000,000 Magnetic product Non magnetic product 800,000 1,200,000 CH Table 9.: Rudabánya mineral processing tailings input and output flows NO x 384,780 Dust 11,660 Table 8.: Rudabánya - emissions

15 Debrecen MSW landfill technology emissions At the municipal solid waste landfill in Debrecen (Hungary), a future processing plant would treat about 3.7 million tons of old MSW during its lifespan, producing around 900 thousand tons of Residue Derived Fuel, 18.7 thousand tons of ferrous and 187 thousand tons of nonferrous products. The use of diesel fuel and 168,000 MWh electricity results in the emission values seen in table 10. Air pollution kg Input t Output t SO CO CO CH NO x Landfill waste 3,746,090 <40 mm fraction 1,873,045 Fe concentrate 18,730 Inert 767,948 Al product (non-fe) 187,304 pressed Ground RDF 899,061 Table 11.: Debrecen MSW landfill processing plant input and output flows Dust Table 10.: Debrecen - emissions

16 Project Coordinator Marco de la Feld ENCO s.r.l.