Abstract: Provided herein are systems and methods for use in wastewater treatment. In some examples, the systems and methods involve different combinations of ion exchange and membrane based systems and processes that can be used to remove radium and recover and purify barium and strontium salts to render the wastewater depleted of those regulated toxic metals. Treated wastewater having less than 12000 pCi/L of any of radium, barium or strontium is then subjected to tertiary treatment where it is subjected to processes in an evaporator/crystallizer which drives out water in the form of vapor, leaving behind salts of innocuous metals such as sodium, calcium, and magnesium, among others. In some examples, water vapor from the processes is condensed to produce water suitable for reuse, such as reuse in the hydro-fracturing process.

Abstract: Methods for rapid sensing of dissolved toxic heavy metals use a hybrid inorganic material (“HIM”), which is synthesized from hydrated iron oxide (“HFO”) and calcium magnesium silicate. HIM thus synthesized is used in sensing dissolved toxic heavy metals. Water containing toxic heavy metals (e.g., lead, copper, zinc, nickel, etc.) is passed through a sorbent bed of HIM, whereupon it shows a sharp drop in pH after a certain length of time. The presence of HFO and calcium magnesium silicates in HIM synergistically provide a precipitous drop in pH, which is characteristic of the concentration and type of toxic heavy metal. Therefore, observing a change in pH indicates the presence and identity of heavy metal ions in a test water sample.