Desupersaturation of RO Concentrates by Addition of Coagulant and Surfactant

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Qingfeng Yang¹  Yangqiao Liu²  Hasson David³  Dmitry Lisitsin³  Raphael Semiat³ 

[1] School of Environmental Science and Engineering, Shanghai Jiao Tong University;State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences;GWRI Rabin Desalination Research Laboratory, Department of Chemical Engineering, Technion-Israel Institute of Technology

关键词: Desalination;    Reverse Osmosis;    Concentrate;    Desupersaturation;    Coagulant;    Surfactant;   

DOI  :  10.1252/jcej.07WE035

来源: Maruzen Company Ltd

【 摘 要 】

References(32)Cited-By(5)One way for the reuse of reverse osmosis (RO) concentrates and thus increasing the water recovery is to recycle part of the brine concentrate to the feed, after precipitating the scaling salts such as CaSO4/CaCO3 held in solution by antiscalants. However, antiscalants impart considerable stability to the supersaturated solution. In the present study, desupersaturation of RO CaSO4 concentrate in the presence of antiscalants was studied by addition of coagulant polyaluminum chloride (PACl) and surfactant sodium dodecyl sulfate (SDS). Simulated experiments for testing the changes in antiscalant concentration were also conducted. The results indicated that under certain conditions, the above methods were effective for desupersaturation of RO concentrate. After the removal precipitation reactions, the calculated supersaturation ratio of the test solution deceased to about 1.0, which demonstrated that the test solution reached thermodynamic equilibrium. With respect to the removal of scaling salt, it was found to follow the second order kinetics. The removal of scaling salt was always accompanied by the adsorption precipitation of antiscalants. The ecomonic analyses show the proposed methods were feasible.

【 授权许可】

Unknown