The Utilization of Cellulosic Biomass in treating AMD and the Subsequent Generation of Fermentable Sugars

摘要

The drainage from closed and abandoned mines is often acidic with elevated heavy metal concentrations. The interaction between acid mine drainage (AMD) and the environment has a significant impact. Whilst temporary remediation can lessen this impact, complete amelioration is only possible using active and/or passive treatment. Active technologies are often costly and can produce a secondary waste stream which may require additional treatment. In this project we explored a passive option combining different technologies. We recognise AMD as a resource of sulphuric acid which we used as a pre-treatment on cellulosic feedstock. Following this, we enzymatically digested the partially hydrolysed cellulose to produce fermentable sugars (which could be used to produce bioethanol). Concurrently, the pH of the AMD increased from 2.11 to 5.46 and 62% of the iron was removed from solution. Previous research has shown that sulfate is also remediated (primarily through dissimilatory sulfate reduction [DSR]). In this research we were successfully able to combine two separate, yet established technologies and were able to remediate AMD with a cellulosic feedstock through DSR and Fe precipitation, whilst being able to use the cellulose residue as a feedstock for bioethanol production.