The invention relates to a system for the treatment of drinking water, comprising a softening system with an ion exchanger. This ion exchanger is regenerated using an alkali salt, in particular sodium chloride or potassium chloride.

Downstream of the water softening system and upstream of an extraction point, an ion exchanger loaded with hydrogen is arranged followed by a mineralization material which releases calcium, magnesium, and/or silicon.

A new family of rare-earth silicate compositions and the synthetic methods used to prepare them. The materials have open-framework structures and are characterized by their ion-exchange properties. They are represented by the following empirical formula:

A.sup.r+.sub.pM.sup.s+.sub.1xM.sup.t+.sub.xSi.sub.nO.sub.m

where A is an exchangeable cation such as sodium, M is at least one element selected from the group of rare-earth elements, and M is a framework metal having a valence of +2, +3, +4, or +5. The rare-earth silicate materials have utility in various cation-exchange applications such as dialysis and removal of toxic metals from the gastrointestinal tract.

A new family of rare-earth silicate compositions and the synthetic methods used to prepare them. The materials have open-framework structures and are characterized by their ion-exchange properties. They are represented by the following empirical formula:

A.sup.r+.sub.pM.sup.s+.sub.1xM.sup.t+.sub.xSi.sub.nO.sub.m

where A is an exchangeable cation such as sodium, M is at least one element selected from the group of rare-earth elements, and M is a framework metal having a valence of +2, +3, +4, or +5. The rare-earth silicate materials have utility in various cation-exchange applications such as dialysis and removal of toxic metals from the gastrointestinal tract.

A process for removing Pb.sup.2+ ions from fluids, such as gastrointestinal fluids is described. The process involves contacting gastrointestinal fluid with a particulate metal titanate ion exchanger represented by the empirical formula:

A.sub.mTi.sub.xM.sub.yO.sub.z

where A is an exchangeable cation selected from the group consisting of potassium ion, sodium ion, lithium ion, calcium ion, magnesium ion, hydronium ion, and mixtures thereof, and M is optionally at least one framework metal selected from niobium (5+), zirconium (4+), tin (4+), iron (3+), iron (2+), cobalt (2+), and manganese (2+). The particulate metal titanate ion exchangers of the present disclosure are synthesized in the presence of complexing agents, including at least one multihydroxyl-containing complexing agent (MHCA), which facilitate metal transport and incorporation while imparting beneficial properties such as large aggregate size, well-behaved particle size distribution, and macroporosity.

A process for removing Pb.sup.2+ ions from fluids, such as gastrointestinal fluids is described. The process involves contacting gastrointestinal fluid with a particulate metal titanate ion exchanger represented by the empirical formula:

A.sub.mTi.sub.xM.sub.yO.sub.z

where A is an exchangeable cation selected from the group consisting of potassium ion, sodium ion, lithium ion, calcium ion, magnesium ion, hydronium ion, and mixtures thereof, and M is optionally at least one framework metal selected from niobium (5+), zirconium (4+), tin (4+), iron (3+), iron (2+), cobalt (2+), and manganese (2+). The particulate metal titanate ion exchangers of the present disclosure are synthesized in the presence of complexing agents, including at least one multihydroxyl-containing complexing agent (MHCA), which facilitate metal transport and incorporation while imparting beneficial properties such as large aggregate size, well-behaved particle size distribution, and macroporosity.

Shaped articles and methods for forming shaped articles are provided. In one embodiment, a method for forming a shaped article includes providing a hydroxy metal oxide binder precursor in a solution of hydroxy metal oxide binder precursor. The method mixes a primary ion exchange composition with the solution of hydroxy metal oxide binder precursor. Further, the method mixes a solid with the solution of hydroxy metal oxide binder precursor. The method includes converting the hydroxy metal oxide binder precursor to a hydroxy metal oxide binder. Also, the method includes forming the shaped article from the primary ion exchange composition, the hydroxy metal oxide binder, and the solid.

Shaped articles and methods for forming shaped articles are provided. In one embodiment, a method for forming a shaped article includes providing a hydroxy metal oxide binder precursor in a solution of hydroxy metal oxide binder precursor. The method mixes a primary ion exchange composition with the solution of hydroxy metal oxide binder precursor. Further, the method mixes a solid with the solution of hydroxy metal oxide binder precursor. The method includes converting the hydroxy metal oxide binder precursor to a hydroxy metal oxide binder. Also, the method includes forming the shaped article from the primary ion exchange composition, the hydroxy metal oxide binder, and the solid.

A method of sorbent dialysis is provided for enhanced removal of uremic toxins, such as toxic anions and/or organic solutes, from spent dialysate. More highly adsorbable zirconium polymeric complexes of these anions and/or organic solutes can be initially formed in spent dialysate by treatment with zirconium salt solution or other zirconium cation source, and then removed with adsorbent to provide purified or regenerated dialysate. Sorbent dialysis systems for detoxifying spent dialysate containing toxic anions and organic solutes are also provided.

A method of sorbent dialysis is provided for enhanced removal of uremic toxins, such as toxic anions and/or organic solutes, from spent dialysate. More highly adsorbable zirconium polymeric complexes of these anions and/or organic solutes can be initially formed in spent dialysate by treatment with zirconium salt solution or other zirconium cation source, and then removed with adsorbent to provide purified or regenerated dialysate. Sorbent dialysis systems for detoxifying spent dialysate containing toxic anions and organic solutes are also provided.

The invention relates to devices, systems, and methods for recharging zirconium phosphate in a reusable zirconium phosphate sorbent module. The devices, systems, and methods provide for customization of the zirconium phosphate effluent pH based on the needs of the user and system. The devices systems and methods also provide for calculation of the volumes of recharge solution needed for fully recharging the zirconium phosphate modules.