Utilization of paper wastes as renewable resource of lignocellulosic constituents has the opportunity to promote a cleaner environment and to prepare valuable materials. This paper describes our study on an isolation of low-fiber powder cellulose from two grades of wastes as feedstocks: waste newsprint paper and cardboard wrapper through recycling including a thermal defibration, an alkali treatment with a solution of NaOH with a concentration from 0.03 to 1.00 М, a bleaching with a solution of Н2О2 with a concentration from 0.8 to 2.6 М followed with an acid hydrolysis of the pretreated species with a solution of HNO3 of 1.5 and 3.0 M. An impact of the pretreatment on sizes of fibers was evaluated with a stereoscopic microscopy. The powder celluloses obtained as a result of the acid hydrolysis exhibited the structure of cellulose I revealed with a WAXS method and were of a high-grade purity, according to EDXA. Sorption capacities of the powder celluloses from the waste cardboard and newsprint towards a dye methylene blue were 6.67 mg∙g-1 and 8.75 mg∙g-1 correspondingly.