Acid Mine Drainage (AMD) is a serious environmental problem and the focus of a great deal of research. Passive treatment systems associated with wetlands and Anoxic Limestone Drains (ALDs) provide a low-cost, low-maintenance treatment in contrast to continuous chemical metering. The ALD adds alkalinity to the water allowing for a more rapid formation of iron precipitates. The abiotic oxidation ponds associated with these systems are expected to precipitate about 10-20 g/sq m-day of iron. The focus of this research is to evaluate two different ALD passive treatment systems in order to find ways to improve the efficiency of the abiotic oxidation of ferrous, thereby reducing the amount of land area required to treat the discharge. The two systems evaluated differed in that one system is a channel system, while the other is a series of ponds. The channel system has a large excess of alkalinity while the pond system has net mineral acidity. The study of the systems was conducted over a one-year period starting in January 1998 and ended in January 1999. The evaluation of each system included monitoring the chemistry and using MINTEQA2, a chemical equilibrium computer program to assist in the analysis. Of all the major cations in solution, ferrous is the only one that is removed in the system.

An ongoing concern is acid mine drainage (AMD) from abandoned sulphidic mines in the Sydney coalfield, which threatens local water bodies and fishing industries if left untreated. This work focuses on evaluating the performance of two semi-passive treatment systems at the Neville Street facility that treat this AMD, which is acidic and contains heavy metals such as iron, manganese, and aluminum. These treatment systems include caustic soda addition, aeration cascades, settling ponds, and constructed wetlands. Current monthly sampling by a local government agency may or may not represent worst-case scenarios as sampling may not coincide with conditions that could impact performance, such as peak loading. This work was divided into three research objectives: (1) characterize system performance during peak loading, (2) statistically evaluate treatment performance, and (3) develop a treatment performance model of the constructed wetlands. Analysis of sampling data during peak loading events indicates that both systems are effectively removing iron from the mine water with effluent readings meeting federal and provincial guidelines. However, inlet iron concentrations have been increasing over time for both systems; thus, exceedances of guideline limits could become a concern in the future. Due to newly adopted federal and provincial guidelines for manganese and sulphate, exceedances of these guideline limits have been or are likely to become a concern in the near future. Modeling of wetland treatment performance using a modified tanks-in-series (TIS) model revealed the necessity for site-specific calibration of model constants. Areal rate constants at 20 °C for iron were developed for both systems based on design and average operating conditions. The design areal rate constants at 20 °C for the two systems were 2,325 m/year and 1,380 m/year; the average areal rate constants at 20 °C were 1,930 m/year and 560 m/year.

While natural processes have been remediating acidic water exhibiting elevated dissolved metals for eons, engineers and scientists have been trying to mimic nature in the treatment of mining influenced water for only about 50 years. The technical community has adopted the term “passive treatment” to describe the technology. The design of passive treatment systems is based on the application of multidisciplinary engineering sciences including biogeochemistry, hydraulics, physics, microbiology, and agronomics to name a few. Consequently, there are many opportunities to not quite “get it right” in passive treatment system design, construction, and operation. Fortunately, Mother Nature can be quite forgiving and sometimes a design or operational hiccup can reveal new insights. The case histories presented in this review reflect the learning experiences of a mining engineer whose technical education barely touched on the fundamentals of passive treatment system design. Early system designs were often based on the findings of other practitioners who were gracious enough to share their knowledge at pre-internet conferences and in easy-to-understand publications. Indeed, the current state of practice of passive treatment design rests on the shoulders of a few brilliant pioneers, most of whom are still with us. This review continues the sharing tradition. The common thread among the mini-case histories discussed is that most are from bench- and pilot-scale testing programs, which reinforces the benefits of small-scale testing as an economical way to accumulate valuable lessons learned experience with minimum risk.

Part of Groundwater Set - Buy all six books and save over 30% on buying separately! Biffaward Winner 2002 The Clean Rivers Trust has fought off stiff competition to become the Research and Development - Technology Category winner at the Biffaward Awards 2002, with its project "Technology Analysis of Acid Mine Drainage Treatment Methods". Minewater Treatment - Technology, Application and Policy, was produced based on the findings of the research to aid in the selection, design and implementation of the most appropriate treatment techniques for particular minewater discharges. Much work has been carried out in recent decades concerning minewater treatment, both in the UK and worldwide. Many different bodies and organizations are involved in developing minewater treatment processes and schemes. Minewater Treatment addresses the need for a single source of state-of-the-art information that draws all the latest research material together. Key features of the book include: a full literature review of minewater treatment throughout the world an overview of relevant legislation and policy in a global context a review of currently available methods for treating minewater worldwide a site specific inventory of minewater treatment schemes within the UK, including compilation of available monitoring data and assessment of performance a review of emerging and innovative minewater treatment technologies and consideration of related academic research within the UK a comprehensive list of active and innovative minewater treatment technologies that are not currently compiled in a book or other review publication a detailed summary and recommendations section assessing the applicability, efficiency and cost-effectiveness of minewater treatment schemes Relevant scientific subject matter is presented in a concise, easily accessible manner to assist with the objective assessment of the progress made to date. Heavily illustrated with many colour photographs, the book allows best use to be made of the collective experience of minewater treatment practitioners throughout the UK, whilst at the same time placing the UK experience within a global context. An invaluable reference work for mining companies, consultants, planning officers, environmental research scientists, environmental agencies, water utilities and regulatory bodies, Minewater Treatment is a definitive source of information on minewater treatment technologies and will help facilitate the selection of the most appropriate technique required to tackle particular minewater discharge problems. Contents The minewater problem Treatment options Existing sites in the UK: Case studies Existing sites in the UK: Site summaries Summary & conclusions