Effective biotreatment of acidic mine water and hospital wastewater using fluidized-bed reactors

Abstract

A laboratory-scale sulfate-reducing fluidized bed reactor at a controlled mesophilic condition of ±28 °C examined the biotreatment process of real acid mine drainage and hospital wastewater. In an attempt to substitute the carbon source, the study used the hospital wastewater in this regard. In this study, there was no supplement of carbon source during the treatment, but only the hospital wastewater provided the dissolved organic carbon. The process evaluated a biological treatment efficiency in stepwise phases, monitoring the effect of retention time, influent pH, and sulfates. The overall removal for the effluent COD concentrations and sulfate were between 39.5 mg/l and 42 mg/l at COD/SO42− ratio of 0.68 and hydraulic retention time of 8 h. The overall COD oxidation and sulfate reduction performance of the reactor was recorded as an average of 96 % and 97 %, correspondingly. The sulfide concentration averaged 235 mg/l, and the alkalinity generated in sulfidogenic organic from hospital wastewater neutralized the acid in mine water. The metal removal efficiencies documented at HRT of 8 h, were all above 98 %. The biological treatment further recorded the removal efficiencies of 44 % for naproxen and 55 % for ibuprofen pharmaceutical compounds as an additional advantage to the system.