Effect of Chemically Treated Leather Shaving Addition on characteristics and microstructure of OPC mortars

Abstract

The growing concern with environmental issues in tanneries and the search for a technological solution to their wastes are evaluated in this study. The leather shaving was chemically treated aiming the immobilization of the chromium ion on ordinary Portland cement (OPC) matrix. Cementitious mortars were obtained by adding different proportions of waste treated solutions (5 and 10% compared to the cement mass) and after 28 days, the samples were evaluated in relation to their physical properties, axial compressive strength and, for the most promising compositions, microstructural characterization analyses tests were realized. Results showed that the alternatives used for the pretreatment were effective for the leather shaving dissolution; but the results analysis describes little change in pH values when the treated waste is added in three different media. The best axial compressive strength after 28 days age were obtained by addition of diluted phosphoric acid solution at low concentration, although this addition minimize the Portlandite formation and favor the calcium phosphate formation.

Strength and Microstructure Assessment of Partially Replaced Ordinary Portland Cement and Calcium Sulfoaluminate Cement with Pozzolans and Spent Coffee Grounds

“…C-S-H, which, due to its poorly crystalline structure, could not be identified in the XRD results, was visible in the SEM images. The ettringite, exhibiting a needle-like structure, and portlandite, which has a laminar structure, were found in these images [ 91 , 92 , 93 , 94 ]. AFm phases, which derive from portlandite, also exhibit a layered structure [ 95 , 96 , 97 ].…”

Screening and Characterization of Hexavalent Chromium Degrading Bacteria From Industrial Samples

“…(KX710177) isolated from workplace effluent, survived in the additional concentration of the metal (VI). Also, Shewanella lochia microorganism reduced the metal from the wastewater by the additional cellular method [16][17][18][19].…”

Review - Characterization of rubber compounds with post-industrial leather waste // Revisión - Caracterización de compuestos de caucho con residuos de cuero posindustrial

“…Los estados de oxidación del cromo oscilan entre -2 y +6, no obstante el estado de oxidación cromo +6 es altamente tóxico comparada con la del estado de oxidación cromo +3, esto se atribuye a la diferencia de geometría entre ambos elementos, donde la geometría tetraédrica del cromo +6 puede penetrar fácilmente por la piel humana [15]. Esto sin contar con la presencia de ácidos ricos en azufre y nitrógeno [3].…”