Alternative Considerations Biotechnology Usage of anaerobic sulfate reducing bacteria requires special conditions with constant nutrient feeding, pH, and temperature, is not economic option, which make it unlikely applicable at low costs without an important research work. Separation using membranes (electrodialisis, reverse osmosis, ultrafiltration) and ionic interchanging resins. These alternatives don’t seem to be feasible because the effluent nature affects the membranes as much as the resins; it’s expensive in large volumes. The main problems are high calcium and sulfate concentration that obstruct and destroy the base material of resins and membranes (polymeric or ceramic). Evaporations and crystallization. Even when these alternatives are actually possible from a technical point of view, it can be extremely costly given the large volume of effluent that needs to be treated. Sulfate precipitation techniques (bario salts with/without regeneration and via etringgite formation. Bario salt precipitation is feasible, but quite expensive. In former studies indicating FAD is efficient isolating BsSO4, when adding sodium oleate. When forming etringgite, there are some patent and pilot tests, but none with an industrial application.

Table 4: Considerations about applying technologies [3,4,25].