Staging of anaerobic processes for reduction of chronically high concentrations of propionic acid

Authors: Duran, Metin; Speece, R.E.

Source: Water Environment Research, Volume 70, Number 2, March/April 1998 , pp. 241-248(8)

Publisher: Water Environment Federation

Buy & download fulltext article:

Price: $30.00 plus tax (Refund Policy)

Abstract:

The objective of this research was the reduction of chronic elevated propionate from a bench-scale, anaerobic completely stirred tank reactor (CSTR) without biomass recycle treating synthetic molasses wastewater. Pretreatment and posttreatment alternatives were specifically examined using a high-food-to-microorganism (F/M) contact chamber as the preliminary operation unit in one case and an upflow anaerobic sludge blanket (UASB) reactor as the posttreatment unit in the second case. The high-F/M contact reactor unit, operated before the main reactor, was a two-stage (not a two-phase) configuration.

After the feed contacted biomass that was recycled from the main reactor for a period of 1 day in a high-F/M contact reactor, the entire contents of the high-F/M contact reactor were transferred back to the main reactor. This brief contact operation resulted in a dramatic decrease in propionate concentrations in the effluent of the main reactor, which had been producing consistently high concentrations for approximately 4 months. After incorporation of the high-F/M contact reactor in the preliminary treatment step, the propionic acid concentration dropped significantly, from 1 050 mg/L to 300 mg/L. The results of this investigation showed that the contact time and F/M ratio in the high-F/M reactor were critical parameters in determining the efficacy of the two-stage configuration.

In the second part of the study, the effluent from the main reactor (not incorporating a precontact reactor) was subjected to posttreatment by a UASB reactor filled with granular biomass. After an acclimation period of approximately 1 month, which provided a hydraulic retention time of 1 day in the UASB unit, the concentration of approximately 1 050 mg/L of propionic acid in the main reactor effluent fell to less than the quantification limit of 20 mg/L in the effluent of the UASB posttreatment unit. The overall success of both portions of the study seem to demonstrate the inappropriateness of using a one-stage CSTR process configuration for anaerobic metabolism of propionate derived from carbohydrate wastewaters.

Keywords: PROPIONIC ACID; ACETIC ACID; ANAEROBIC TREATMENT; TWO-STAGE STREATMENT

Document Type: Research article

DOI: http://dx.doi.org/10.2175/106143098X127099

Publication date: 1998-03-01

More about this publication?

Water Environment Research� (WER�) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year.

Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.
Editorial Board
Information for Authors
Submit a Paper
Subscribe to this Title
Membership Information
Information for Advertisers
WEF Bookstore
ingentaconnect is not responsible for the content or availability of external websites

Staging of anaerobic processes for reduction of chronically high concentrations of propionic acid

Buy & download fulltext article:

Tools

Key

Text size:

Useful pages