Cruceru, MihailMihailCruceruNicolau, MargaretaMargaretaNicolau2017-04-242017-04-241986-05-30Patent no. RO 89593-Ahttp://hdl.handle.net/123456789/947Patent Assignee Name(s) and Code(s): COMB CHIMIC DROBETA; INST EPURAREA APELORIn the 1 st step the spent C is treated successively with NaOH solns. having decreasing concns., respectively of 15-, 10-, 5-, 2.25-, 1 and 0.5%, at 70 deg. C, for 2 hrs. for each treatment. In a 2nd step, the C is washed with 0.05% Na metabisulphite soln. at pH 1 .5. Washing is continued with an aq. soln. of 0.001 % Na metabisulphite, until the washing water reaches pH 4.5.en-USActive carbonRegenerationTwo-step spent active carbon regeneration by treatment with sodium hydroxide soln. and then washing with sodium metabisulphite soln.Patent