A novel process intensification approach of recovering creatine from its wastewater by batch foam fractionation

• Foam fractionation was used to recover creatine from its wastewater.
• A novel two-stage batch foam fractionation was developed.
• SDS played a dual role of collector and frother during the separation process.
• SDS could be recycled in the two-stage batch foam fractionation.

Foam fractionation is a cost-effective water treatment technology and it uses bubbles as the media for separating surfactants or non-surface materials from their aqueous solutions, where non-surface materials can be attached to the gas–liquid interface by using a surfactant as the collector. A novel two-stage batch foam fractionation was developed for recovering creatine from its wastewater. The objective of the first stage was to concentrate creatine from its wastewater and sodium dodecyl sulfate (SDS) was used as the collector. Under the suitable operating conditions, the enrichment ratio and the recovery percentage of creatine were 3.1 and 70.6%, respectively. Subsequently, the second stage was performed for isolating SDS from creatine by using the first stage foamate as the feeding solution. Under the suitable operating conditions, the recovery percentage of SDS reached 76.2% and creatine was massively remained in the residual solution because the complexation between creatine and SDS was eliminated through adjusting pH to 8.0. So, the total recovery percentage of creatine reached 59.3% and SDS in the second stage foamate could be reused for recovering creatine from its wastewater.