Biochemical Method for Extraction and Reuse of Protein and Chromium from Chrome Leather Shavings: A Waste to Wealth Approach

Abstract

Chrome shavings are one of the major solid wastes generated during the leather making process. The presence of chromium in waste creates difficulty in disposing to landfill and incineration. Growing environmental concern about the toxicity and environmental impact of the chromium solid waste generated from the tannery has become key issue. In this work, a study has been made to extract protein from chrome shavings through a biochemical method. In this biochemical method the combination of chemical and enzyme processes have been employed to achieve the optimum extraction of protein. Optimization studies on enzyme and alkali concentration, time, pH and temperature on protein extraction were performed. Further, protein extraction by protease mixed with ¦Á-amylase has also been investigated. It was found that there was significant change in the protein extraction by protease in the presence of ¦Á-amylase. The protein extraction efficiency by conventional and biochemical method is found to be 60 and 80%, respectively. This study provides a biochemical method of hydrolysis for chrome shavings to protein and chromium. RESUMENLas virutas de cromo son uno de los principales residuos s¨®lidos generados durante el proceso de fabricaci¨®n de cuero. La presencia de cromo en los residuos crea dificultades en la disposici¨®n en vertederos y su incineraci¨®n. La creciente preocupaci¨®n medioambiental acerca de la toxicidad y del impacto medioambiental de los residuos s¨®lidos de cromo generada a partir de la curtiembre se ha convertido en tema clave. En este trabajo, se ha hecho un estudio para extraer prote¨ªna a partir de virutas de cromo a trav¨¦s de un m¨¦todo bioqu¨ªmico. En este m¨¦todo bioqu¨ªmico la combinaci¨®n de procesos qu¨ªmicos y enzimas se han empleado para lograr la extracci¨®n ¨®ptima de la prote¨ªna. Se realizaron estudios de optimizaci¨®n de la enzima y la concentraci¨®n del ¨¢lcali, tiempo, pH y la temperatura de extracci¨®n de la prote¨ªna. Adem¨¢s, la extracci¨®n de prote¨ªnas mediante proteasa mezclada con ¦Á-amilasa tambi¨¦n ha sido investigada. Se encontr¨® que hubo cambio significativo en la extracci¨®n de prote¨ªnas por la proteasa en presencia de ¦Á-amilasa. La eficiencia de la extracci¨®n de prote¨ªnas por el m¨¦todo convencional y bioqu¨ªmico fue de 60 y 80%, respectivamente. Este estudio proporciona un m¨¦todo bioqu¨ªmico de hidr¨®lisis de virutas de cromo hacia prote¨ªna y cromo.