China Disodium Salt of 1-Hydroxy Ethylidene-1, 1-Diphosphonic Acid (HEDP. Na2) ; CAS No. 7414-83-7, Find details about China HEDP. Na2, Water Treatment Chemicals from Disodium Salt of 1-Hydroxy Ethylidene-1, 1-Diphosphonic Acid (HEDP. Na2) ; CAS No. 7414-83-7