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  • Research of titration curves of red mud samples
    270-276
    Views:
    84

    The aluminium demand is increasing worldwide, so the amount of red mud, which produced during the production of aluminium, is constantly increasing, also. The researching of the economical processing of the byproduct has been under way for a long time, but the industrial implementation of recovery technology, that is suitable in all aspects, has not yet been realized. The use of by-products, in addition to reduce the risk of contamination of environmental elements, may be useful for the recovery of valuable metals, which contained therein.

  • Laboratory Testing of Rediffusion of Contaminants Using DKS-Permeameter
    41-48
    Views:
    117

    Decades long hydrocarbon contaminations effecting heterogenous groundwater systems is a common problem both in Hungary and worldwide. Only the treatment of aquifer layers is possible with remediation technologies, so the contaminations remained in the aquitards are released back to the treated porous layer  after the treatment due to the changes in concentration-gradient. This process is the so-called back-diffusion: as a result, the previously removed contaminations appear in the remediated layer again. In order to get better understanding of the rediffusion process and the influencing parameters series of measurements were carried out at the University of Miskolc Faculty of Earth Science and Engineering using a special laboratory device called DKS-permeameter. With the help of some small modifications it can be used for the modeling of backdiffusion. Artificially contaminated soil samples were built in the DKS-permeameter from which contaminanant release occured due to back-diffusion. The concentration values were determined with spectrophotometric measurements.

  • Laboratory investigation of the rediffusion of contaminants originated from the aquiclude
    232-238
    Views:
    96

    Many organic pollutants are released into the soil and thus into the groundwater due to anthropogenic effects (a chain of harmful human activities). Layers with low permeability (e.g. clay) play an important role in blocking the path of these contamintants. However, due to their sorption and diffusion properties, such aquiclude layers can also serve as long-term sources of contamination. Once the layer is contaminated, it is already very difficult to recultivate, and there is a potential for the pollutant to spread to higher permeability layers by slow diffusion processes. This phenomenon is defined as a so-called rediffusion process, in which contaminants are retransferred from the aquiclude to the layer with higher permeability. The purpose of this study is to demonstrate the possibility of modeling this rediffusion process in a laboratory scale and to quantify the effect of influencing parameters on pollutant transport.

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