Authors Kallen Mulilo Nalyanya, Ronald K. Rop , Arthur Onyuka, Zephania Birech , Paul Kamau
Aloe barbadensis miller (Abm) mixed with carrageenan has been investigated as an alternative eco benign ingredient in mitigating hexavalent chromium Cr (VI) formation in thermally and photoaged wet blue and leather crust. The effect of post-tanning operations on the formation of Cr (VI) in wet blue and leather crusts due to spontaneous and accelerated ageing caused by exposure to the temperature of 80 “C and UV radiations for 132 hours is also presented. The Cr (VI) content was analyzed according to ISO 17075 standard procedure of Diphenyl carbazide and UV-VIS spectrophotometer at 540 nm. The levels of Cr (VI) in retanned wet blue leather were detectably high, while for tanned, dyed and fat liquored crusts, the levels were below detection limit of 0.2247 mg/kg. After ageing, the Cr (VI) content increased to a detectable level, the highest recorded in retanned wet blue, followed by fat liquored crust and with the lowest levels recorded in dyed wet blue leather. In all the aged samples, the levels were remarkably higher than the recommended 3 mg/kg. The levels of Cr (VI) in wet blue leathers processed with Aloe barbadensis miller/carrageenan were below detection limit of 3.587 mg/kg, even after exposing the samples to accelerated ageing conditions. Aloe barbadensis miller /carrageenan completely inhibits formation of Cr (VI) in wet blue and leather crusts. Aloe barbadensis miller/carrageenan will contribute to the eco benign and sustainable production of leather under the superior chrome-tanning technology.
