(90b) Carboxyethyl Amine Sodium Salts As Novel Draw Solutes for Forward Osmosis Applications | AIChE

(90b) Carboxyethyl Amine Sodium Salts As Novel Draw Solutes for Forward Osmosis Applications

Authors 

Long, Q. - Presenter, Huazhong University of Science & Technology
Chai, Z. - Presenter, Huazhong University of Science & Technology

For the successful implement of forward osmosis (FO) technology, development of suitable draw solutes is a critical issue, which however still faces problems of severe leakage and energy-intensive recovery. In this work, a series of novel carboxyethyl amine sodium salts (CASSs) with different carboxyl group numbers, i.e., diethylenetriamine pentapropionic acid sodium (DTPP-Na), triethylenetetramine hexapropionic acid sodium (TTHP-Na), and tetraethylenepentamine heptapropionic acid sodium (TPHP-Na), are synthesized and employed as draw solutes for FO application. Chemical structures of the synthesized CASSs are examined by 1HNMR and HRMS. Their FO performances are investigated and compared in terms of different physicochemical properties. The effects of the CASS concentration on the osmotic pressure and viscosity of the draw solutions, as well as the resulted FO performance are also systematically investigated. A high water flux of 23.07 LMH and an acceptable reverse salt flux of 0.75 gMH can be achieved with 0.5 g/mL TTHP-Na draw solution under PRO mode, which is superior to most other draw solutes reported in previous literatures. TTHP-Na draw solution is further evaluated to recycle the Congo red solution to examine its applicability for waste water treatment. This study provides useful insights for the molecular design of novel high-performance draw solutes for future FO applications.