Effect of high influent sulfate on anaerobic wastewater treatment

A laboratory-scale study was conducted using a completely mixed reactor with a constant influent-total-organic carbon (TOC) of 3750 mg/L to evaluate the effect of increasing influent-sulfate levels on anaerobic-treatment performance. The sulfate levels were increased stepwise from 333 to 666, 1000,...

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Veröffentlicht in:Water environment research : a research publication of the Water Environment Federation. - 1998. - 77(2005), 7 vom: 15. Nov., Seite 3037-46
1. Verfasser: Khanal, Samir Kumar (VerfasserIn)
Weitere Verfasser: Huang, Ju-Chang
Format: Aufsatz
Sprache:English
Veröffentlicht: 2005
Zugriff auf das übergeordnete Werk:Water environment research : a research publication of the Water Environment Federation
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Industrial Waste Sulfates Water Pollutants, Chemical Carbon 7440-44-0 Methane OP0UW79H66
Beschreibung
Zusammenfassung:A laboratory-scale study was conducted using a completely mixed reactor with a constant influent-total-organic carbon (TOC) of 3750 mg/L to evaluate the effect of increasing influent-sulfate levels on anaerobic-treatment performance. The sulfate levels were increased stepwise from 333 to 666, 1000, 1333 and 1666 mg S/L. The results showed that an elevation of influent sulfate actually increased the TOC removal efficiency as long as the produced sulfide level did not induce toxicity. At 1333 mg S/L influent sulfate, the produced dissolved sulfide was 613 mg S/L (free sulfide = 228 mg S/L), which started to impose toxicity to the methane-producing bacteria (MPB). It was also found that the percent electron flow to the sulfate-reducing pathway increased with the increasing influent sulfate, but the direction toward the methanogenesis was correspondingly reduced. Nevertheless, under the experimental conditions tested, the majority of the influent organics was still degraded through the methanogenic pathway. Through this study, an oxidation-reduction-potential (ORP)-based oxygenation process was developed for online oxidation of sulfide in recirculating biogas. With controlled oxygen injection to raise the reactor's ORP by 25 mV, the residual sulfide in the reactor was almost totally eliminated. In case of over oxygenation, any excess oxygen was quickly consumed by the facultative organisms in the reactor, thereby imposing no toxicity to the MPB
Beschreibung:Date Completed 28.03.2006
Date Revised 22.09.2019
published: Print
Citation Status MEDLINE
ISSN:1554-7531