Acidification is a universal problem at all mining sites in which oxygenated water comes in contact with sulfide minerals or other reduced sulfur compounds. An International Workshop was held in September 1995 at the Department for Inland Water Research of the UFZ-Centre for Environmental Research in Magdeburg on the limnology of lakes created by open-cast lignite mining, emphasizing the often observed geogenic acidification after oxidation of pyrite. Topics of interest were case studies on the limnology of acid lakes, e.g. bacteriologically enhanced processes related to heavy metal mobilization and acid generation, the ecology of sulfur-acidic lakes, and on the inorganic processes of acidification. Furthermore, concepts for the prevention and the abatement of acidification were addressed including the causes of acidification, and the options for reducing the output of acidified groundwater from overburden dumps, for acid control during the flooding of open-cast mines, and potential measures for induced in situ biological neutralization. This volume has 25 chapters including a chapter with results of group discussions about the topics mentioned above and further problems that were identified during the meeting. The monograph gives a baseline of the state of science on the worldwide problem of geogenic adidification of lakes following human mining activities, and how to handle this environmental problem.

Inhalt

1 Introduction.- 1 Natural and Anthropogenic Sulfuric Acidification of Lakes.- 2 Regional Geology of the Lignite Mining Districts in Eastern Germany.- 2 Limnological Case Studies on Acid Lakes.- 3 Chemical Characteristics of Water and Sediment in Acid Mining Lakes of the Lusatian Lignite District.- 4 In-Lake Neutralization of Acid Mine Lakes.- 5 Acid Generation and Metal Immobilization in the Vicinity of a Naturally Acidic Lake in Central Yukon Territory, Canada.- 6 Geochemical Behaviour of Submerged Pyrite-Rich Tailings in Canadian Lakes.- 7 Phytoplankton Composition and Biomass Spectra Created by Flow Cytometry and Zooplankton Composition in Mining Lakes of Different States of Acidification.- 8 Ecological Potentials for Planktonic Development and Food Web Interactions in Extremely Acidic Mining Lakes in Lusatia.- 9 Colonization and Development of Vegetational in Mining Lakes of the Lusatian Lignite Area in Dependence on Water Genesis.- 3 Inorganic Processes of Acidification.- 10 Pyrite Chemistry: The Key for Abatement of Acid Mine Drainage.- 11 Chemical Reactions in Aquifers Influenced by Sulfide Oxidation and in Sulfide Oxidation Zones.- 12 Oxygen as a Limiting Factor for Pyrite Weathering in the Overburden of Open Pit Lignite Areas.- 13 Effects of Superficial Tertiary Dump Substrates and Recultivation Variants on Acid Output, Salt Leaching and Development of Seepage Water Quality.- 4 Remediation Concepts and Case Studies.- 14 Microbial Processes for Potential in Situ Remediation of Acidic Lakes.- 15 Biological Abatement of Acid Mine Drainage: The Role of Acidophilic Protozoa and Other Indigenous Microflora.- 16 Treatment of Mine Drainage by Anoxic Limestone Drains and Constructed Wetlands.- 17 Biological Polishing of Zinc in a Mine Waste Management Area.- 18 Development of a Long-Term Strategy for the Treatment of Acid Mine Drainage at Wheal Jane.- 19 Bioremediation of Metals in Acid Tailings by Mixed Microbial Mats.- 20 Managing the pH of an Acid Lake by Adding Phosphate Fertiliser.- 21 Model Calculations for Active Treatment of Acidic, Iron-Containing Lake Water Assuming Mining Lakes as Chemical Reactors.- 22 Ways of Controlling Acid by Ecotechnology.- 5 Summary of Group Discussions and Conclusions.- 23 Pyrite Oxidation Control.- 24 Limnological Fundaments of Acid Mining Lakes.- 25 Approaches for the Restoration of Strongly Acidic Mining Lakes.