Before and after in Norton, WV. Vegetation gains a strong foothold while bactericide helps keep the damaging bacteria under control. The real culprit in AMD is not the pyrite, but the bacteria that live in the pyritic environment. By controlling the damaging bacteria, normal vegetationpromoting heterotrophic bacteria are allowed to prosper in the top soil, promoting successful revegetation. middle part of the circle is gone, but the natural cycle should successfully continue without it. This self-revitalizing soil action is what allows operators to "walkaway" from a reclaimed site, avoiding on-going maintenance and water treatment expenses, which could otherwise last indefinitely. A green thumb cific. In order to determine the ap- During reclamation, the bacteri- Costs cide is applied to the site before it is covered with top soil. As rainwater passes the material on its way to the pyrite, it picks up the bactericide which inhibits the growth of the AMD bacteria. With acid production reduced, nature has the opportunity to reestablish plant life which eventually stabilizes the land. The system can be applied using standard reclamation equipment such as hydroseeders or disks. The application of these materials is a step easily incorporated into normal reclamation practices using normal crews without special tools or additional skilled labor. How long till things turn green again? Each site is unique, but gen erally the results are immediate. Most experts believe that once a life cycle is established on disturbed lands, it will become self-perpetuating. Four demonstration sites using bactericides are now almost three years old and appear to have returned to their natural state with dramatic and ongoing reductions in acid generation. One in West Virginia has even received a reclamation award. Bactericides treatment is site-spe The system is not especially expensive. In ballpark figures, $1500 to $4000 an acre will cover original site evaluation, sampling, analysis of data for a specific dosage, product and product-application and followup. In fact, the cost of the initial application may sometimes be offset by the savings in topsoil cover. Over a period of time, however, the most expensive part of any reclamation program is doing it the second time, or having post-reclamation acid drainage. Bactericides appear to be the least expensive because they are working the first time. This avoids maintenance and reclaiming the site again as well as eliminating the cost of continuously treating the AMD with acid neutralizing materials. By applying the treatment during active mining, the water treatment cost can be reduced substantially, perhaps as much as 50% to 90%. Also, the site is subsequently more responsive to revegetation and far less susceptible to post-reclamation acid drainage. Regular but infrequent applications of the materials sprayed over the surface of stored coal, gob, refuse, mine tailings, or toxic overburden will inhibit the ac tivity of the AMD bacteria. (Roughly, costs run about 10 to 20 cents per ton of refuse if sprayed on the belt as the refuse leaves the plant.) The treatments will decrease the acidity, consequently helping prevent metals from dissolving in water draining from active sites. Resultant decreases in water treatment costs will be evident. Other benefits: Although the pellets have a finite life, only one application is needed. Also, a lesser thickness of soil cover is needed, and everyone knows top soil is hard to find, plus, you have to revegetate the area you borrowed the top soil from. And, you don't have to build a swamp (bog). The use of bactericides should have wide applications in other forms of mining, whenever Thiobacillus ferrooxidans is a major factor in the formation of damaging acids. Acknowledgment Thanks go to BFGoodrich for supplying the data for this article (ProMac Systems, The BFGoodrich Company, 9921 Brecksville Rd, Brecksville, OH 44141). ProMac products are manufactured at BFGoodrich's Marietta, Ohio plant. REFERENCES 1. Rastogi, Vijay and Sobek, A.A., The Eco- 3. Dugan, P.R., "Bacterial Ecology of Strip PARTE Report of Investigations 8847 Control of Acid Drainage From Coal Refuse Using Anionic Surfactants By Robert L. P. Kleinmann and Patricia M. Erickson UNITED STATES DEPARTMENT OF THE INTERIOR William P. Clark, Secretary BUREAU OF MINES Robert C. Horton, Director Library of Congress Cataloging in Publication Data: Kleinmann, Robert L. P Control of acid drainage from coal refuse using anionic surfactants. (Report of investigations ; 8847) Bibliography: p. 13-16. Supt. of Docs. no.: [ 28.23:8847. 1. Acid mine drainage. 2. Coal mine waste. 3. Industrial microbiology. 4. Surface active agents. I. Erickson, Patricia M. II. Title. III. Series: Report of investigations (United States. Bureau of Mines); 8847. TN23.U43 (TD899.M5] 622s [628.1'6832] 83-600348 2. 3. Effect of anionic detergents on acid production from pyritic coal.. Hydroseeder being used to spray sodium lauryl sulfate on 11-acre refuse area in southern West Virginia.... 1. Acidity and total dissolved iron versus pH for a series of experiments conducted in laboratory simulations of a coal refuse pile..... ILLUSTRATIONS 4. Effect of sodium lauryl sulfate on acidity of drainage from 11-acre inactive coal refuse pile in southern West Virginia...... 8 5. Effect of sodium lauryl sulfate on sulfate concentrations at the southern 8 6. 7. Effect of sodium lauryl sulfate on manganese concentrations at the southern 8 8. Effect of sodium lauryl sulfate on runoff water quality at 8-acre active coal refuse pile in northern West Virginia. Effect of sodium lauryl sulfate on iron concentrations at the southern West 8 9 TABLE 1. Effects of sodium lauryl sulfate on crushed sterilized pyritic coal in a laboratory simulation of the intermediate belt of the zone of aeration.... 5 |