Sugarcane bagasse as slow release electron donor for sulfate reduction

• Grant number: 19/27154-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2020
• End date: March 31, 2022
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Denise Bevilaqua
• Grantee: Guilherme Salvador Peres Neto
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Biological sulfate reduction associated with chemical precipitation of metal sulfide is a promising strategy for acid mine drainage (AMD) treatment, and metal recovery. However, the formation of fine particles of metal sulphides in bioreactors makes their recovery difficult. The use of slow release electron donor could overcome this problem, since it would would prevent the formation of supersaturated sulfide zones, and consequently help in the formation of settling particles. The present work aims to study the potential of using sugarcane bagasse as a slow release electron donor for sulfate reduction. The first step will be the enrichment of a microbial consortium with hydrolytic and sulfate-reducing bacteria. The following stages will include some tests to understand fundamental aspects of the use of sugarcane bagasse as an electron donor. Thus, an assay will be performed to determine the compound that is used by the BRS to determine whether these organisms use carbohydrate or any fermentation product. Different ratios of sugarcane bagasse mass to sulfate mass will also be tested, to determine which ratio maximizes sulfide production and how long it takes for the electrons released from the bagasse to be exhausted. A further test will determine the viability of the process with low initial pH (3,5) and the toxicity of sulfide on the enriched activity of the enriched microbial community. (AU)