Basics of Instrumentation and Control

Abstract: Electrodeionization (EDI) is a widely studied process ranging from applications in wastewater clean-up in the food and beverage industry to purifying organic compounds. To date, there are no apparent studies on applying this technology to produced wastewater recovered from hydraulic fracking sites. Water consumption within hydraulic fracturing sites can reach in the upwards of millions of gallons per site, so a need for a water recycling process becomes necessary within areas where water requirements are scarce. Implementation of an EDI module that is capable of handling high salt solutions from produced wastewater in subsequent fracturing practices will decrease overall water demands, making this an environmentally sustainable process as well. This study will focus on the selective removal of high concentrations of ions using ion-selective membranes and ion exchange wafers in Wafer-Enhanced Electrodeionization (WE-EDI) of hydraulic fracturing solutions for improved water recovery and reuse within industrial applications. Experiments were performed using a WE-EDI setup with varied wafer composition and thickness in comparison with electrodialysis for selective removal of divalent ions (Ca2+) over monovalent ions (Na+ ) from simulated and fracking solutions. Research sought to show that when increasing the wafer thickness and changing the composition (weak acid compared to strong acid resins) there would be a greater overall current efficiency observed and subsequently lower power consumption. This research concluded that there is some degree of enhanced selectivity with increased wafer size, as well as varied composition compared to a traditional ED system. Continued research is recommended to conclude uncertainties, eliminate areas of system performance error and to further solidify all hypothesizes within this research.

Introduction: The City of Winnipeg has initiated a program to perform upgrades to the wastewater treatment systems at the NEWPCC, SEWPCC, and WEWPCC facilities. As part of these upgrades, automation systems are required for process control and monitoring. These automation systems must be installed to provide effective monitoring and control of the wastewater treatment processes. There are many methods of implementing an automation system, and the purpose of this document is to provide an overall strategy for automation installations that are consistent with the City’s needs. It is expected that this document will form the basis for future design work.