Mine water treatment using recycled concrete aggregate as a sustainable locally-available material
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Journal Title
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Volume Title
Insinööritieteiden korkeakoulu |
Master's thesis
Authors
Date
2020-06-15
Department
Major/Subject
Mcode
ENG3079
Degree programme
Master's Programme in Creative Sustainability (CS)
Language
en
Pages
55+8
Series
Abstract
Acid Mine Drainage (AMD) is considered to be a major concern for the contamination of water resources. AMD originates from the oxidation of sulfide minerals in mine activities. The concentrations of heavy metals and sulfate in typical AMD water exceed the water standards recommended by the environmental quality standards. It negatively affects the quality of water resources. This research aims to introduce a new cost-effective and sustainable method for treating AMD specifically where it is generated in the surface water of the closed and abandoned mines using a globally-locally available Recycled Concrete Aggregate (RCA) material. The objective of the current research is to determine the effect of the RCA on the concentration of sulfate, iron, zinc, copper and manganese removal, resulting in AMD and neutralizing its acidity. RCA was tested for sulfate and heavy metals ions removal from Aijala tailing pond water via batch experimental mode. The adsorptive properties of RCA before and after adsorption were characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, elemental mapping, Brunauer-Emmett-Teller surface area measurements, and X-ray Diffraction. Furthermore, the organic functional groups of materials were identified by Fourier Transform Infrared Spectroscopy. Adsorption parameters such as dosage, contact time, the size of adsorbent particles, and the solution pH, were optimized for optimal removal performance. The pH point of zero charge for the RCA sample was defined. The effect of equilibrium concentration on the adsorption of sulfate was identified Freundlich isotherm fitted by as an excellent fit to the equilibrium values (R2=1). The results revealed that RCA is a potential eco-friendly material for AMD treatment. The concentration of sulfate from AMD was reduced by 83-86%, iron 100%, manganese 94-96%, copper 61-72%, zinc 96-97%, and lead 75-77%. The pH value in Aijala AMD water increased immediately and reached the neutral by using small quantities of RCA (≤1g/L).Description
Supervisor
Vahala, RikuThesis advisor
Yazdani, Roza MaryamKauppila, Tommi
Keywords
acid mine drainage, mine water treatment, recycled concrete aggregate, adsorption, sulphate, trace metals