Sorption in Acidic Environment – Biosorbents in Comparison with Commercial Adsorbents

Abstract

The remains of human activities may be seen in several places of the landscape in positive or negative form. Probably the most common phenomenon that fundamentally impacts the country is mining activity. The problems connected with these activities especially arise at the end of the mining, closure and abandonment of the mining area. The most serious negative impact represents acid mine drainage. Acid mine drainage is a worldwide problem, leading to ecological destruction in river basins and the contamination of water sources by sulphuric acid and heavy metals, including arsenic, copper, zinc or lead. Once acid-generating rock is crushed and exposed to oxidizing conditions of the surface environment, is very difficult to reduce or stop acid generation, and can continue for tens or hundreds of years until the available sulphide minerals are exhausted. In order to minimize negative impacts of acid mine drainage appropriate treatment process has to be chosen. With respect to the amount of compound in acid mine drainage is difficult to find effective and inexpensive solution. One of the possible ways of treatment seems to be a sorption. In recent years research is increasingly focused on this effective and cheap method that provides the quantity of application possibilities for removal of compounds from aqueous environment. Acid mine drainage especially with its low pH value and high amount of different inorganic compounds represents very difficult system for each treatment process. For this reason it is necessary to use partial steps in sorption research to reach valuable knowledge leading to set up final treatment process in real conditions. This study is focused on the utilization of biosorbents and commercial adsorbents for copper removal from model sulphuric acid solutions (pH 4). Sorption of copper from single-component aqueous system and also from acid mine drainage was investigated. For this purpose four types of sorbents were used (hemp shives, peat, zeolite and synthetic sorbent Slovakite). The objective of this work was to evaluate the differences between sorption efficiencies of biosorbents and commercial adsorbents.