Filter materials for metal removal from mine drainage—a review

Abstract

A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage.

The Potential Use of Cassava Peel for Treatment of Mine Water in Mozambique

“…Organic filter material such as lignite [47] and rice husk [48] were used successfully in the removal of metal and sulfate from mine drainage. According to [4], there are some disadvantages in using filter material in large scale, namely: high cost, variable composition of mine water, instability, and risk of leaching hazard substances from filter material.…”

“…cassava peel) is very effective in removing metals at low concentration compared to conventional methods at large scale [2]. Developing countries cannot afford much budget to protect their local environment and bioremediation [3], adsorption [2] and filtration [4] seem to be economical strategies that, if applied properly, can be viable solutions for mine water treatment in, for instance, Moatize (Mozambique).…”

Testing Metallic Iron Filtration Systems for Decentralized Water Treatment at Pilot Scale

“…The presentation above has already shown that O2 scavengers including SSF should precede Fe 0 /sand filters. The situation of multiple contaminant mixtures which may not be efficiently treated by a single technology [189] is an opportunity to compare Fe 0 filtration to other available affordable filtration systems [190] and shape multi-barrier systems involving Fe 0 filters. Contaminants possess different properties with respect to adsorptive behavior, degradation potential, molecular size, solubility, and surface charge [191].…”

“…Because multiple contaminant mixtures may contain positively charged species as well, it is important to comparatively test Fe 0 and other materials under the same operational conditions. Relevant filter materials include activated carbons, bark, bio-carbons (biochar), wood charcoal, calcareous shale, chitin, chitosan, commercial ion exchangers, dairy manure compost, dolomite, fly ash, lignite, limestone, olivine, peat, rice husks, steel slag materials, vegetal compost, yeast, and zeolites [190,192].…”

Research of Sustainable Use of Tire Shreds in Landfill

“…Before 2007, all waste was dumped in the landfills, which were not equipped with leachate or gas collection systems. Therefore, leachate and gas found their way into the surrounding environment [8][9][10][11][12]. The use of as many recycling materials as possible is an important point.…”