In alternative embodiments, the invention provides processes and methods for the recovery or the removal of the so-called Minor Elements consisting of iron, aluminum and magnesium (expressed as oxides), from wet-process phosphoric acid using a continuous ion exchange approach. In alternative embodiments, use of processes and methods of the invention allows for the reduction of these Minor Elements with minimal phosphate losses and dilution in order to produce a phosphoric acid that is suitable for the production of fertilizer products such as world-class diammonium phosphate (DAP), merchant-grade phosphoric acid, superphosphoric acid, and other phosphoric acid products. Further, use of the invention would allow the use of lower grade phosphate rock or ore, which would greatly expand the potential phosphate rock reserve base for phosphate mining activities, and allow for better overall utilization of resources from a given developed mine site.

A method for harmless disposal and resource utilization of resin desorption liquid generated in the ion exchange process is provided. Resin desorption liquid is channeled into an electrolytic tank, which is arranged with an inlet and an outlet; the anode and the cathode within the electrolytic tank are separately connected to a stabilized power supply; both the direct and indirect oxidation process and occurred at the anode can decompose the organic pollutants in the desorption liquid; with necessary replenishment of fresh regeneration agent, the treated desorption liquid can exert excellent performance in regenerating saturated resin; the recycled use of resin desorption liquid is therefore realized, which consequently avoids unnecessary waste of regeneration agent and reduces the final yield of the desorption liquid. This method is characterized by being convenient in operation, without addition of extra reagents, without secondary pollution, and suitable for the desorption liquid with wide pH variations.

The present invention provides processes for removing nitrogen species from fresh water or high salinity water recirculated aquaculture systems. The processes are based on physico-chemical treatments which are performed at ambient temperatures and at low p H values thus keeping the total ammonia nitrogen concentrations below a value which is considered detrimental for the growth or survival rate of cultured fish/shrimp.

The present invention provides processes for removing nitrogen species from fresh water or high salinity water recirculated aquaculture systems. The processes are based on physico-chemical treatments which are performed at ambient temperatures and at low p H values thus keeping the total ammonia nitrogen concentrations below a value which is considered detrimental for the growth or survival rate of cultured fish/shrimp.

Processes for removing nitrogen species from fresh water or high salinity water recirculated aquaculture systems. The processes are based on physico-chemical treatments which are performed at ambient temperatures and at low pH values thus keeping the total ammonia nitrogen concentrations below a value which is considered detrimental for the growth or survival rate of cultured fish/shrimp.

Processes for removing nitrogen species from fresh water or high salinity water recirculated aquaculture systems. The processes are based on physico-chemical treatments which are performed at ambient temperatures and at low pH values thus keeping the total ammonia nitrogen concentrations below a value which is considered detrimental for the growth or survival rate of cultured fish/shrimp.

Disclosed herein is a process for carrying out an ion exchange process which involves providing two interacting sets of banks of continuously stirred tank reactors (CSTR's) each containing a bed of ion exchange resin and causing the resin to move in one direction through each bank of reactors and the feed solution and/or or eluant in the opposite direction. In carrying out the process, a feed solution is introduced in a first reactor causing dissolved ions to be captured on the resin, eluant is introduced into a reactor upstream of the first reactor in the direction of resin movement causing ions captured on the resin to be removed into the eluant and eluant rich in ions removed from the resin will be taken from a reactor upstream of the reactor in which the eluant was introduced, for further processing. Thus, in this form of the invention there is, in effect, a loading bank of reactors in which ions from the feed solution are captured followed by a regenerating bank of reactors in which the eluant removes the ions captured on the resin and regenerates the resin.

Methods and systems for acid regeneration of ion exchange resins are disclosed. Acid resins designed for use in a variety of cleaning application using a water source use a treated, softened, acidic water source according to the invention. Various methods of using the softened acidic water generated by acid regenerate-able ion exchange resins are disclosed to beneficially reduce spotting, filming and scale buildup on treated surfaces, reduce and/or eliminate the need for polymers, threshold reagents and/or rinse aids, and using protons generated in the acidic water effluent for triggering events useful in various cleaning applications.

A method for recovering an anionic fluorinated emulsifier comprises contacting a strongly basic ion exchange resin having an anionic fluorinated emulsifier adsorbed thereon to an aqueous inorganic acid solution and an organic solvent comprising a nitrile group. The anionic fluorinated emulsifier is eluted from the strongly basic ion exchange resin, and a liquid phase comprising an acid of the anionic fluorinated emulsifier is obtained. An acid of the anionic fluorinated emulsifier is recovered from the liquid phase. The strongly basic ion exchange resin and the liquid phase are preferably separated, after the aqueous inorganic acid solution and the organic solvent are contacted to the strongly basic ion exchange resin, and before the acid of the anionic fluorinated emulsifier is recovered from the liquid phase.

A method for recovering an anionic fluorinated emulsifier comprises contacting a strongly basic ion exchange resin having an anionic fluorinated emulsifier adsorbed thereon to an aqueous inorganic acid solution and an organic solvent comprising a nitrile group. The anionic fluorinated emulsifier is eluted from the strongly basic ion exchange resin, and a liquid phase comprising an acid of the anionic fluorinated emulsifier is obtained. An acid of the anionic fluorinated emulsifier is recovered from the liquid phase. The strongly basic ion exchange resin and the liquid phase are preferably separated, after the aqueous inorganic acid solution and the organic solvent are contacted to the strongly basic ion exchange resin, and before the acid of the anionic fluorinated emulsifier is recovered from the liquid phase.