An integrated algal sulphate reducing high rate ponding process for the treatment of acid mine drainage wastewaters

Acid mine drainage pollution may be associated with large water volume flow s and exceptionally long periods of time over which the drainage may requir e treatment. While the use and role of sulphate reducing bacteria has been demonstrated in active treatment systems for acid mine drainage remediation , reactor size requirement and the cost and availability of the carbon and electron donor source are factors which constrain process development. Litt le attention has focussed on the use of waste stabilisation pending process es for acid mine drainage treatment. Wastewater pending is a mature technol ogy for the treatment of large water volumes and its use as a basis for app ropriate reactor design for acid mine drainage treatment is described inclu ding high rates of sulphate reduction and the precipitation of metal sulphi des. Together with the co-disposal of organic wastes, algal biomass is gene rated as an independent carbon source for SRB production. Treatment of tann ery effluent in a custom-designed high rate algal pending process, and its use as a carbon source in the generation and precipitation of metal sulphid es, has been demonstrated through piloting to the implementation of a full- scale process. The treatment of both mine drainage and zinc refinery wastew aters are reported. A complementary role for microalgal production in the g eneration of alkalinity and bioadsorptive removal of metals has been utilis ed and an Integrated 'Algal Sulphate Reducing Pending Process for the Treat ment of Acidic and Metal Wastewaters' (ASPAM) has been described.