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. • f <br /> 4 . <br /> • r <br /> achieve a 50% reduction in acidity Weinmann and Erickson, 1986) . <br /> BFGoodrich has since shown reductions as high as 98% (see Figure 6) . <br /> Summary <br /> The mine operator is at' the mercy of his geology, meteorology, and <br /> ambient conditions. Considering that alkaline and , phosphorous <br /> additions are after-the-fact approaches to reclamation; the logical <br /> alternative for AMD abatement is bacterial inhibition. ProMa,e'"Systems — <br /> bactericides weaken ' the .grease-like coating of •, the bacterium that <br /> 0.enables it to live in a hostile environment where pal may fall below 1.9 <br /> while the- pH of the interior of the bacterium's cell is near neutral. <br /> The protective membrane around the cell becomes permeable and the acid <br /> penetrates the cell membrane and retards or destroys the organism <br /> (Tuttle, et al, 1977) . This mechanism prevents T. ferrooxidans from <br /> developing a resistance to the active ingredients in ProMac. , <br /> PROMAC SYSTEMS - <br /> Anionic surfactants are some of the most effective compounds that <br /> can be used to inhibit the growth and activity of T. ferrooxidans; yet, <br /> without controlled release systems, these chemicals quickly biodegrade, <br /> adsorb to soil materials,. and become diluted by- runoff. '. Spray <br /> applications of bactericides can inhibit acid formation for three to <br /> six months, then treatment has to be repeated for effective control of <br /> acid formation in active ore piles. <br /> The BFGoodrich Company has developed and refined long-term <br /> controlled release pellets blended with highly effective inhibitors. <br /> "these polymer pellets - slowly - release ingredients that selectively <br /> inhibit Thiobacilli and promote the growth of beneficial heterotrophic <br /> bacteria to provide a soil environment conducive to plant growth. <br /> Controlled release systems must be designed to function in varied <br /> environments. The chemical- and physical environment plus hydrology and <br /> climate must be considered. Some 'specific factors which were taken <br /> into account during the development of the controlled release pellet <br /> for acid generation inhibition are reviewed in Table 1. <br /> ProMac Systems function" when water contacts and activates the <br /> controlled " release - pellets. A quantity of bactericide is carried with <br /> the incoming water to' points-- of bacterial action on the- pyrite <br /> surfaces. Here, the ingredients contact the bacteria and biooxidation <br /> is halted at the source (Sobek'and Rastogi, 1986). _- <br /> -Climate and Altitude <br /> Treatment with ProMac Systems bactericides is site specific and <br /> designed to function irr a variety of climates from and to tropical. <br /> " Dosage rates using different pellet combinations are formulated`to meet <br /> the --conditions of ' climate.- " For -example, arid regions 'that- receive <br />