engleski

Zinc removal from aqueous solutions by precipitation and coagulation/ flocculation

In this study, precipitation and coagulation/flocculation were applied to remove zinc from aqueous solutions. In order to optimise the conditions of their application, we have studied the effect of pH and dosage of different coagulants. Experiments were performed using the inorganic coagulant FeCl3 and the commercial organic polymeric coagulants 815 C and A 130 by the standard JAR test procedure. Based on the residual zinc concentration in supernatant solutions and the settling velocity, the zinc removal efficiency has been determined. The results show that efficient removal of zinc from aqueous solutions can be performed by precipitation at pH=8.5. The coagulants A 130 and 815 C in the optimum dose of 0.1 vol % increased the settling velocity by two times compared to the experiment without coagulants. This is of great importance for overall costs in practical application. Based on the settling characteristic of suspensions and the Kynch theory, the parameters of the sedimentation process have been calculated for conditions without and with the optimal addition of coagulant.

precipitation ; coagulation/flocculation ; zinc removal

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