A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

As pellets grow from seed/sand in a fluidized bed pellent reactor, the weight of the reactor is measured and the density of the contents of the reactor is calculated, and the input flow of untreated water, water treatment chemical, and seed/sand are adjusted to provide improved removal of water hardness while reducing fine particulates in the outflow of softened water from the reactor.

A process for treating frac flowback that contains barium, naturally occurring radioactive materials (NORM) and hardness for minimizing the amount of sludge produced that contains hazardous levels of NORM by employing a dual stage precipitation process. In the first stage a sulfate source is mixed with the frac flowback and barium sulfate and NORM is precipitated, the frac flowback is subjected to a solids-liquid separation process to produce a first effluent and a first sludge. In the second stage hardness is precipitated from the first effluent by addition of an alkali reagent, said first effluent is also subjected to solids-liquid separation producing a second effluent and a second sludge. The first sludge is recycled and mixed with the frac flowback and the sulfate source in a sufficient amount to maintain the NORM concentration in the second sludge at or below a threshold level.

A process for treating frac flowback that contains barium, naturally occurring radioactive materials (NORM) and hardness for minimizing the amount of sludge produced that contains hazardous levels of NORM by employing a dual stage precipitation process. In the first stage a sulfate source is mixed with the frac flowback and barium sulfate and NORM is precipitated, the frac flowback is subjected to a solids-liquid separation process to produce a first effluent and a first sludge. In the second stage hardness is precipitated from the first effluent by addition of an alkali reagent, said first effluent is also subjected to solids-liquid separation producing a second effluent and a second sludge. The first sludge is recycled and mixed with the frac flowback and the sulfate source in a sufficient amount to maintain the NORM concentration in the second sludge at or below a threshold level.

According to some embodiments, a system for desalination of a liquid comprises at least one primary treatment process, at least one secondary treatment process, wherein the at least one secondary treatment process comprises at least one reactor, and at least one tertiary treatment process, wherein the at least one primary treatment process is configured to adjust a pH of the liquid to target pH level and to add at least one chemical additive to the liquid, wherein the at least one reactor is configured to heat the liquid to a temperature of at least 350° F. and to supply a pressure to the liquid to maintain the liquid in a liquid state, and wherein the dissolved salt of the liquid is configured to react with at least a portion of the at least one chemical additive to form an insoluble product within the at least one reactor.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water is concentrated in a reverse osmosis step and salt from the resulting solution is removed in supercritical conditions prior to destruction of PFAS in supercritical conditions.

A treatment system for removing hardness, silicon, and turbidity from wastewater having a high salt concentration, comprising an integrated reaction apparatus comprising a reaction box and a chemical drug adding device, and a membrane separation apparatus comprising a membrane pool and a membrane component. The wastewater having the high salt concentration enters the reaction box; a required chemical drug is added to the wastewater by means of the chemical drug adding device; the chemical drug and the wastewater are fully mixed and reacted to produce different kinds of sludge particles; a sludge particle mixed liquid directly enters the membrane pool; under the action of an aeration device, the sludge particle mixed liquid is in a suspension state and uniform in concentration, and is screened and filtered by the membrane component; and produced water is discharged from the membrane pool, and intercepted sludge particles are discharged from the membrane pool.

A treatment system for removing hardness, silicon, and turbidity from wastewater having a high salt concentration, comprising an integrated reaction apparatus comprising a reaction box and a chemical drug adding device, and a membrane separation apparatus comprising a membrane pool and a membrane component. The wastewater having the high salt concentration enters the reaction box; a required chemical drug is added to the wastewater by means of the chemical drug adding device; the chemical drug and the wastewater are fully mixed and reacted to produce different kinds of sludge particles; a sludge particle mixed liquid directly enters the membrane pool; under the action of an aeration device, the sludge particle mixed liquid is in a suspension state and uniform in concentration, and is screened and filtered by the membrane component; and produced water is discharged from the membrane pool, and intercepted sludge particles are discharged from the membrane pool.