title: Performance of a sulfide-oxidizing, sulfur-producing membrane biofilm reactor treating sulfide-containing bioreactor effluent.
abstract: Sulfide-containing waste streams are generated in mining, petrochemical plants, tanneries, viscose rayon manufacture, and the gasification of coal. Colorless sulfur bacteria can oxidize sulfide to elemental sulfur (S°), which can be recovered, when oxygen is their electron acceptor. This study evaluated sulfide oxidation and S° recovery in an oxygen-based membrane biofilm reactor (MBfR) treating the effluent from a sulfidogenic anaerobic baffled reactor. Sulfide oxidation efficiency (37-99%) and S° recovery (64-89% of oxidized sulfide) could be controlled by manipulating the sulfide loading, oxygen pressure to the fibers, and hydraulic retention time (HRT). For example, too-low oxygen pressure decreased S° recovery due to decreased sulfide oxidation, but too-high oxygen pressure lowered S° recovery due to its oxidation to sulfate. Most importantly, high sulfide oxidation (>98%) and conversion to S° (>75%) could be achieved together when the sulfide loading was less than 1.7 mol/m²·d and the O₂ pressure was sufficient to give an O₂ flux of at least 1.5 mol/m²·d. However, higher sulfide loading could be compensated by a higher O₂ pressure, and the best performance occurred when the sulfide loading was high (2 molS/m²·d), the O₂ pressure was high (∼1 atm), and the HRT was short (1.9 h). Membrane fouling caused a low O₂ flux, which led to low sulfide-oxidation efficiency, but fouling could be reversed by mild acid washing.
authors: Department of Environmental Engineering, Harran University , Osmanbey Campus, 63000 Sanliurfa, Turkey. erkansahinkaya@yahoo.com
authors: Erkan
authors: E
authors: Sahinkaya
authors: Halil
authors: H
authors: Hasar
authors: Anna H
authors: AH
authors: Kaksonen
authors: Bruce E
authors: BE
authors: Rittmann
mesh_terms: D001420:Bacteria, Aerobic / Q000502:physiology*; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology; D004867:Equipment Design; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000295:instrumentation*
chemical_list: D013440:Sulfides; D013455:Sulfur; D010100:Oxygen