Experimental study on freezing-based methods in treating simulated high salt organic wastewater.

Simulated high salt organic wastewater samples with the chemical oxygen demand (COD) and the salt concentration of 10,000 mg/L were prepared in the experiments. Two combined freezing-based methods were employed to deal with the simulated wastewater, which are the freezing and centrifugal method (FCM), and the freezing, gravity-induced and centrifugal method (FGCM). The salt removal efficiency, the COD removal efficiency and the ice recovery rate of the treated ice samples were investigated. The results showed that for FCM experiments, more than 70% of organic matter and salt content can be removed rapidly under the rotation rate of 2,000 rpm and the centrifugation duration of 2 min. Extending the centrifugation duration or further increasing the rotation rate can’t improve COD and salt removal efficiencies greatly. For FGCM experiments, the COD and salt removal efficiencies increase with the concentrated wastewater drainage proportion or increase slightly in lower ambient temperature. The salt concentration and COD of the treated ice samples can meet the requirement of China’s wastewater discharge standards under certain gravity-induced wastewater drainage proportion or ambient temperature. [ABSTRACT FROM AUTHOR]