Effect of environmentally friendly reverse osmosis scale inhibitors on inorganic calcium carbonate scale

A highly efficient and environmentally friendly composite scale inhibitor was developed using sodium carboxymethyl cellulose (CMC-Na) and polyepoxysuccinic acid (PESA). The PESA:CMC-Na=1:3 optimum ratio was observed with a maximum enhancement factor of 1.81. The film flux attenuation rate was reduced from 24.98 % to 6.2 % at optimal operational condition (concentration 80 mg/L, initial pH 7) for actual mine water treatment. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis results showed that the addition of the compound scale inhibitor transformed the calcium carbonate scale from calcite to vaterite with looser and more porous structure. The molecular dynamics simulation results demonstrate that composite scale inhibitor had a higher binding energy with calcite than that of PESA, CMC-Na, resulting in the restrained formation of calcite. This study provides a new technical idea for the application of scale inhibitor to improve the treatment efficiency of mine water by reverse osmosis.