(606e) Distributed Small Water Treatment and Desalination Systems for Upgrading Impaired Groundwater for Potable Use

Membrane-based water treatment and desalination systems are particularly suited for treatment of impaired groundwater (e.g., due to contamination by nitrates, pesticides, and high salinity) of small communities. However, deployment of distributed water treatment and desalination (DWTD) systems, particularly where 24/7 operator availability is infeasible, requires system design that enables remote monitoring and advanced process operational strategies that autonomously respond to: (i) fluctuations in water feed quality, (ii) variability of product water use patterns, and (iii) regulatory and/or process requirements (setpoints) concerning product water quality and residual stream generation. Accordingly, a novel and flexible water treatment/desalination (FLEWTD) MF-UF-RO was developed to accommodate a wide range of feed water salinity and aide recovery range, while producing potable water that meets safe drinking water requirements. The treatment system was developed with local and remote supervisory decision support systems were developed to: (i) forecast system performance, (ii) detect process performance degradation and sensor faults, (iii) mitigate membrane scaling and fouling, and (iv) implement cyberinfrastructure for remote system monitoring, management and process adjustments. To enable autonomous operation that meets regulatory requirements machine -learning models (RNN-LSTM and GATConv) were developed and integrated with domain knowledge to enable model-based control and decision support. Results from real-world deployment of three distributed FLEWTD systems in Salinas Valley, CA to impaired local community well water demonstrated reliability of the approach in ensuring removal of contaminants such as nitrates, 1,2,3-TCP and reducing salinity to comply with regulatory requirements.