Abstract: A water or wastewater purification process is described for reducing selenium and arsenic concentrations in contaminated water or wastewater streams. Iron loaded cation exchange resins, when contacted with contaminated water or wastewater streams are effective to form immobilized complexes with selenite and arsenate contaminants. The iron loaded resins can be easily regenerated by sequential treatment with acid and a solution of a soluble iron salt.

Abstract: A water or wastewater purification process is described for reducing selenium and arsenic concentrations in contaminated water or wastewater streams. Iron loaded cation exchange resins, when contacted with contaminated water or wastewater streams are effective to form immobilized complexes with selenite and arsenate contaminants. The iron loaded resins can be easily regenerated by sequential treatment with acid and a solution of a soluble iron salt.

Abstract: A system for handling exhausted vermiculite cation exchange particles after they have been used for the removal of heavy metal ions from waste effluents. The exhausted particles are stabilized and removed from the ion exchange column. Stabilization may be by acid solution recirculation through the column prior to particle removal. This is accomplished by preferably using a portable stabilization unit. The stabilized particles are removed from the column by a flushing, backwashing arrangement. After drying, the particles, which are non-hazardous, may be used in a land fill or they may be expanded to produce a lightweight aggregate, insulation, or agricultural material.

Abstract: Heavy Metals contained in industrial waste streams are removed therefrom by flocculation using a source of ferric ions and an alkaline material at a basic pH. Both the flocculated heavy metals and the coagulant chemicals are recovered by acidifying the floc to a pH of between 3.2 and 3.7. This liberates the heavy metals back into solution but does not destroy the floc particles. After separation and removal of the concentrated heavy metal solution, the floc is further acidified to completely dissolve it. This dissolved ferric ion containing solution may then be reused to treat succeeding portions of heavy metal containing waste streams. The concentrated heavy metals solution may also be recycled or the metals contained therein recovered for reuse or disposed of in an acceptable manner.

Abstract: A method and apparatus for water softening using less than approximately 20 micron diameter fine mesh magnetized ion exchange particles in columnar operation. The particles are formed by encapsulating a core of magnetic material in ion exchange resin. The particles are magnetized and disposed in a column where they attach to magnetic mesh retention means such as stainless steel wool. The design of the column permits use of the fine mesh ion exchange particles and their properties of rapid exchange rates and efficient utilization of resin capacity while avoiding prior art problems of plugging, fouling, and excessive pressure drop.

Abstract: A disinfectant composition for use in water conditioning systems is produced by dry mixing sodium chloride and a chlorinated cyanurate and pelletizing the mixture. The composition releases free chlorine to disinfect brine solutions used in regenerating domestic water conditioning ion exchange columns and prevents bacterial contamination of such columns.

Abstract: Multivalent heavy metal ions are removed from metal plating waste streams by passing them through an unexpanded vermiculite cation exchange column. The column is effective to remove copper, zinc, and nickel ions and mixtures thereof. Where cyanide and cyanide-metal complexes are also present in the plating waste stream, the stream is pretreated to destroy the cyanide and cyanide complexes prior to passage through the ion exchange column.

Abstract: Cation exchange water softeners may be regenerated and, then, the regenerant wastes (brine) recovered, treated, and recycled. The result is a closed system which is ecologically beneficial. The regenerant brine is captured in as concentrated a form as possible and then treated with a precipitant such as sodium or potassium carbonate or mixtures of sodium or potassium carbonate with sodium or potassium hydroxide. Calcium and magnesium compounds are precipitated and the supernatant contains sodium or potassium chloride. These are separated within the brine treatment tank, the precipitate being disposed of as a sludge or sludge cake and the supernatant being recycled to the water softener at the time of further regeneration.

Abstract: An exfoliated vermiculite cation-exchange column is used to remove multivalent heavy metals (copper, zinc, nickel, chromium, etc.) from metal plating wastes. The exfoliated vermiculite may be either chemically or relatively low-temperature thermally expanded vermiculite ore. It preferably has a cation exchange capacity of over 80 meq/100g. Exfoliated vermiculite particle sizes of less than approximately 10 mesh are preferred as the column packing. The ion-depleted vermiculite from the exchange column after use can be further expanded thermally and used as a lightweight filling material.