Determination of polyacrylamides in coal washery effluents by ultrafiltration/size-exclusion chromatography-ultraviolet detection techniques

A new, simple, rapid and sensitive method for determination of polyacrylamides (PAM) is described. Flocculants of anionic and cationic PAM were analysed by aqueous size-exclusion high performance liquid chromatography with UV detection. A column of TSK 5000 PW hydrophilic and semi rigid porous polymer gel was used with 0.05 M sodium sulphate as the mobile phase. A TSK gel 2000 PW precolumn was used. Resolution was good, sensitivity was improved over other chromatographic methods, and column life was longer. Relative standard deviation was 5.8 per cent and precision was 2.2 per cent at the 95 per cent confidence level at a concentration of approximately 20 ppm. Ultrafiltration of effluents with a hollow fibre cartridge with nominal molecular weight cut-off of 100,000 slightly reduced recovery of PAM. Application of the technique to coal washery thickener feed effluent is described. The applicability of the method to petroleum industry wastewaters and tailings from mineral processing plants is also discussed.