| To removal U(Ⅵ) from uranium wastewater with bioremediation methods is one ofthe research hotspots. The anaerobic sludge attracted widespread attention because ofits rich biodiversity and high biological activity and settleability.This paper focused on the bioremediation ability of anaerobic sludge whichartificially domesticated. The affecting factors such as different VSS dosage, pH,U(Ⅵ) initial concentration, addition of electron donors, reuse of anaerobic sludgewere performed under batch experiments and the mechanisms for U(Ⅵ) removal werediscussed. The results showed that pH is one of the key factors which influenced theexperiment. High U(Ⅵ) removal ratio could be reached only under proper pH(5.2～6.6). Batch experiment which added zero-valent iron or ethanol as electron donorsshowed2times longer high U(Ⅵ) removal ratio lasted. The speed of U(VI) removalwas in proportion to the VSS dosage. Different initial U(Ⅵ) concentration has littleinfluence on U(Ⅵ) removal ratio. The anaerobic sludge could be reused and themechanism for U(Ⅵ) removal suggested to be redox and adsorption.Extract extracellular polymeric substance (EPS) from anaerobic sludges asadsorbent, observe the adsorption ability of EPS under different pH, EPS dose,concentration of U(Ⅵ), dialysis temperature. The results showed that6is the optimalpH for adsorption. The highest adsorption capability of U6+by EPS is0.891mg/g EPS.The removal rat can reach up to98.3%when the EPS dosage is56.1g/L and the initialconcentration20mg/L. |
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