Aqueous solutions (similar to 0.01-0.2%) of long chain polymers are used during gravity thickening to aggregate particle suspensions. These polymers are often dosed into turbulent flow through submerged pipes (sparges) to maximise their distribution. At high concentrations, these viscoelastic solutions mix poorly with surrounding flows unless highly diluted. If varying the bluff body sparge shape can enhance mixing, such dilution may be avoided. Turbulent mixing of concentrated (0.2%) polymer solutions sparged into turbulent flows within a transparent channel was captured using high-speed imaging to understand the complex mixing phenomena. Square and round sparges were investigated at 0 or 180 degrees to the channel flow. At 0 degrees, vortex shedding from square sparge edges enhanced mixing, but the 180 degrees orientation produced better overall mixing. Image analysis gave the first quantification of flow past bluff bodies issuing viscoelastic fluid jets at industrial flow regimes, from which more appropriate turbulence model closures for fluid dynamics modelling of the process may be derived.