Maximum Removal Efficiency of Barium, Strontium, Radium, and Sulfate with Optimum AMD-Marcellus Flowback Mixing Ratios for Beneficial Use in the Northern Appalachian Basin

Abstract

Mixing of acid mine drainage (AMD) and hydraulic fracturing flowback fluids (HFFF) could represent an efficient management practice to simultaneously manage two complex energy wastewater streams while reducing freshwater resource consumption. AMD discharges offer generally high sulfate concentrations, especially from the bituminous coal region of Pennsylvania; unconventional Marcellus shale gas wells generally yield HFFF enriched in alkaline earth metals such as Sr and Ba, known to cause scaling issues in oil and gas (O&G) production. Mixing the two waters can precipitate HFFF-Ba and -Sr with AMD-SO 4 , therefore removing them from solution. Four AMD discharges and HFFF from two unconventional Marcellus shale gas wells were characterized and mixed in batch reactors for 14 days. Ba could be completely removed from solution within 1 day of mixing in the form Ba x Sr 1−x SO 4 and no further significant precipitation occurred after 2 days. Total removal efficiencies of Ba + Sr + SO 4 and the proportion of Ba and Sr in Ba x Sr 1−x SO 4 depended upon the Ba/Sr ratio in the initial HFFF. A geochemical model was calibrated from batch reactor data and used to identify optimum AMD−HFFF mixing ratios that maximize total removal efficiencies (Ba + Sr + SO 4 ) for reuse in O&G development. Increasing Ba/Sr ratios can enhance total removal efficiency but decrease the efficiency of Ra removal. Thus, treatment objectives and intended beneficial reuse need to be identified prior to optimizing the treatment of HFFF with AMD.

Freshwater Mussel Soft Tissue Incorporates Strontium Isotopic Signatures of Oil and Gas Produced Water

“…Unique and consistent Sr/Ca ratios among dose tank water samples potentially indicate Sr uptake was a metabolic analogue for Ca uptake in the high-dose tank, consistent with previous findings . Alternatively, mineral precipitation and sorption reactions could be contributing to Sr removal. , In contrast, Ba uptake was not correlated with Ca uptake. While we did not measure alkalinity directly, we estimated alkalinity as HCO 3 from the charge balance discrepancy between cations and anions for complexation distribution calculations.…”

Comparison of the Hydraulic Fracturing Water Cycle in China and North America: A Critical Review

“…However, concurrent studies from the U.S. show that uncertainties remain about the adequate treatment of FPW for agricultural use, given findings that mechanisms causing negative impacts on plants can be more synergistic. , These synergistic effects could be related to combined effects from constitutes, such as boron, organic chemicals, and salt, and the accumulation of contaminants in the suspended solids in FPW, which also function as delivery vehicles to animals and plants . Thus, the current guidelines (Table S5) alone may not be sufficient, and further investigation into the causes of these adverse impacts are needed to optimize the treatment technologies and develop proper regulations and guidelines on FPW reuse. − In the U.S., the blending of FPW with acid mine drainage is proposed to be an effective management practice for dual remediation. − Efforts to extract valuable metals such as lithium from FPW also show promise . Beyond lithium, developing techniques for extracting radium, uranium, vanadium, or other rare earth elements are areas worthy of future research .…”

Arsenic release to the environment from hydrocarbon production, storage, transportation, use and waste management

“…They hypothesized that these sediments represent a potential non-point source of these elements into the environment. Little is known about the As content of wastewaters reused for road spreading, as most states require limited chemical analyses or pretreatment (McDevitt et al, 2020), often only oil-water separation. Among the states surveyed by McDevitt et al (2020), only NY and North Dakota (ND) monitored lead (Pb) and As concentrations.…”