Waste to Wealth: Bioprocess for the detoxification of chromium-contaminated solid tannery waste and the exploitation of potential high value-added products

Description of Activity

Authors: Pattanathu K.S.M. Rahman, Mary Greenwell, Mosh Sarkar

Background - The leather industry contributes vast amounts of pollution damaging to aquatic and terrestrial environments. Leather dust is a chromium-contaminated waste produced from the shaving and buffering processes involved in leather tanning. Microorganisms have been investigated for their usefulness in bioremediation and recycling of waste materials. Solid leather waste is the current focus of material to be remediated in this study.

Objective - The present work focuses on the development of a process to degrade the leather dust protein with the aim of removing the chromium bound within the protein. As part of the study, detecting the presence of biosurfactant production was performed to fuel further interest in value-added by-products of the process.

Method - Bacillus subtilis was used to treat the leather dust over a 10 day shake flask study. Daily samples were taken and analysed for chromium content by Atomic Absorption Spectrometry. The surface tension of the shake flask cultures was also investigated to detect for any valuable by-products such as biosurfactants for future prospects of developing an economically viable process.

Results - Chromium concentration demonstrated an exponential increase between 0-120 h in shake flask experiments. In the presence of B. subtilis chromium concentration in cell free supernatant increased from 0.13±0.09 mg/L to 190.81±20.18 mg/L compared to when B. subtilis was absent. Surface tension decreased during fermentation from 53.23±0.92 mN/m to 30.13±0.15 mN/m in 24 h.

Conclusion - This study demonstrates a waste management process,which detoxifies solid tannery waste to reduce environmental pollution, whilst yielding value-added products (such as biosurfactant) to provide an economically viable bioprocess with potential for large-scale development.

Period	15 Mar 2019
Event title	Waste to Wealth Workshop
Event type	Workshop
Location	LondonShow on map