Selection of water treatment processes is a complex task and has to consider many parameters including changes in water quality and quantity and overall economics. The DST is intended to help designers, utilities, and regulators to select treatment trains considering options for beneficial use of treated domestic wastewater. The VBA-based DST is fully automated and selects treatment trains based on input data such as feed water quality and target water quality requirements and other performance criteria. The development of the DST starts with the establishment of a comprehensive water quality and quantity database. Water quality data is compared to beneficial use target water quality requirements and contaminants that need to be treated to meet this beneficial use requirement are selected for treatment based on concentration in feed water. The DST finally suggests a combinations of treatment technologies (a treatment train) capable of providing the required treatment for the intended beneficial use for a given flow back and produced water quality. Meeting the desired treatment level is a priority in the selection process. However, the DST considers additional selection criteria such as footprint, chemical and energy demand, modularity, mobility, and several other factors.
Produced water from oil or gas wells or other impaired water from industrial or domestic sources can be reclaimed for beneficial use for a secondary purpose. Potential beneficial use options include domestic potable use, industrial or agricultural use, fisheries and wildlife, recreation, fire protection, dust suppression, and more. Large volumes of produced water are pumped to the surface during production of oil and gas, including coal bed methane and shale gas, throughout the United States. Disposal of the waste streams to surface water or municipal wastewater treatment plant may pollute surface waters. For instance, in Pennsylvania, discharge of high TDS water has resulted in TDS levels exceeding drinking water standards along the Monongahela River, which is a major source of drinking water . There are needs to develop integrated approaches to improve treatment, handling, disposal, and beneficial use of water brought to the surface during production of shale gas, and other unconventional gas resources. Operators must manage flow back and produced water in a cost-effective manner that complies with state regulatory requirements. GWPC and ALL (2009) list water management options employed at several different shale gas plays. Deep well injection is a primary method to dispose wastewater . Due to limited access to injection wells and/or the desire to recycle the water, other options are currently being employed to manage flow back and produced waters .