Process of preventing pollution of streams

Claim 1

A PROCESS FOR TREATING THE WASH-WATERS FROM BRASS MILLS WHICH COMPRISES PASSING THE RAW WASH-WATERS FROM THE BRASS-PICKLING OPERATION, WHICH WATERS CONTAIN SULFURIC ACID TOGETHER WITH THE SULFATES OF COPPER, ZINC, AND CHROMIUM, THROUGH A BED OF AN INSOLUBLE, INFUSIBLE, ORGANIC, CATION-EXCHANGE MATERIAL WHICH CONTAINS SULFONATE GROUPS AND IN THE FORM OF A SALT OF A MEMBER OF THE CLASS CONSISTING OF SODIUM, CALCIUM, MAGNESIUM, AND AMMONIA, ADSORBING ON SAID BED OF CATION-EXCHANGE MATERIAL THE IONS OF COPPER, ZINC, AND AT LEAST SOME OF THE CHROMIUM IONS, CONTACTING NEUTRALIZING THE EFFLUENT FROM THE BED OF ION-EXCHANGE MATERIAL WITH A COMPOUND FROM THE CLASS CONSISTING OF LIME AND LIMESTONE, PASSING THE RESULTANT AQUEOUS SOLUTION TO WASTE, REGENERATING THE BED OF CATION-EXCHANGE MATERIAL BY PASSING THERETHROUGH AN AQUEOUS SOLUTION OF A WATER-SOLUBLE SALT WHOSE CATION IS THE SAME AS THAT ORIGINALLY COMBINED WITH SAID CATION-EXCHANGE MATERIAL AND WHOSE ANION IS A MEMBER OF THE CLASS CONSISTING OF SULFATE AND CHLORIDE IONS, COLLECTING THE EFFLUENT FROM THE BED OF REGENERATED CATION-EXCHANGE MATERIAL, WHICH EFFLUENT CONTAINS THE IONS OF COPPER, ZINC, AND CHROMIUM, REMOVING COPPER BY DEPOSITING IT FROM SAID EFFLUENT, TREATING THE RESULTANT SOLUTION WITH A COMPOUND WHOSE CATION IS THE SAME AS THAT ORIGINALLY COMBINED WITH SAID CATION-EXCHANGE MATERIAL WHICH COMPOUND IS A MEMBER OF THE CLASS CONSISTING OF SODIUM CARBONATE, SODIUM HYDROXIDE, MANGNESIM OXIDE, MAGNESIUM HYDROXIDE, MAGNESIUM CARBONATE, LIME AND AMMONIUM HYDROXIDE, REMOVING THE RESULTANT PRECIPITATE AND ADJUSTING THE PH OF THE RESULTANT AQUEOUS SOLUTION TO 4 TO 7 WITH A MINERAL ACID WHOSE ANION IS THE SAME AS THE ANION OF THE SALT EMPLOYED TO REGENERATE SAID BED OF CATIONEXCHANGE MATERIAL.