(579f) Rapid Reverse Osmosis (RO) Membrane Performance Analysis Using An Autonomous RO Desalination System

For many communities around the world, seawater and brackish water desalination is increasingly becoming a necessity for augmenting dwindling fresh water supplies. At present, reverse osmosis desalination is the leading technology for brackish and seawater desalination. Widespread implementation of RO technology, however, remains a challenge due to the wide variety of feed water quality, membrane scaling and fouling problems, and suboptimal energy use with the current construction and operational strategy of Ro systems. Given the multitude of challenges of RO desalting, a systematic and robust approach is required for assessing process feasibility, evaluating process strategies (e.g., to minimize fouling/scaling), and optimizing process performance (e.g., with respect to energy use). In the present study, a mini-modular-mobile (M3) RO system capable of autonomous operation and with remote control capability was developed by the UCLA Water Technology Research Center for rapid reverse osmosis membrane performance analysis. The M3 RO system, equipped with readily configurable spiral wound membrane elements, is capable of real time remote monitoring of process stream conditions, automated data acquisition, web-based data storage, and advanced remote control schemes. The system can be used in a once-through or total recycle operational modes . The system enable rapid membrane performance analysis, which in the present work was accomplished in a total recycle mode. Pure water membrane permeability, intrinsic salt rejection, and concentration polarization in the M3 system were characterized over a wide range of operating conditions (i.e., RO water recovery and feed flow rates). Based on the laboratory experiments and data analysis, the range of safe operating conditions for the M3 RO system was characterized for field deployment of desalting brackish water of high mineral scaling propensity. The use of the M3 system was subsequently demonstrated in the field for desalting agricultural drainage source water in California's San Joaquin Valley with high gypsum scaling potential. Rapid membrane performance analysis was demonstrated over a variety of field conditions. The present study introduces a new paradigm RO desalting evaluation using an autonomous system, enabling rapid assessment of RO membrane performance both in controlled laboratory and field settings.

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