Evaluation Method for Performance of Reverse Osmosis Antiscalants Based on the Turbidity

Scale-forming ions can produce crystals in water; meanwhile, antiscalant components may react with chemicals forming insoluble matters. These particles will cause a sharp increase of water turbidity instantaneously. Hence, the change of turbidity can be utilized to judge the formation of particles and furthermore to evaluate antiscalants performance. A study is undertaken to investigate the scale inhibition and the compatibility of reverse osmosis (RO) antiscalants by the turbidity method. The results show that the turbidity method is simple and feasible to assess antiscalants performance, and especially applicable to rapid screening of antiscalants for membrane desalination. It has a good reproducibility and a relative standard deviation (RSD) of measurements in terms of scale inhibition, the compatibility with polyaluminum chlorides (PAC) and cationic polyacrylamide (CPAM) reaches 5.5%, 3.5%, and 4.6%, respectively.