Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Anaerobic treatment of thermal sludge conditioning liquor with granular sludge

Journal Article · · Water Environment Research; (United States)
DOI:https://doi.org/10.2175/WER.65.1.2· OSTI ID:6507663
; ;  [1];  [2]; ;
  1. Japan Sewage Works Agency, Tamano City, Okayama (Japan)
  2. Hokubu-Dai 2 Sewage Treatment Plant, Yokohama City (Japan)

Thermal sludge conditioning liquor was successfully treated by a pilot-scale upflow anaerobic hybrid system with an effective volume of 10.4 m[sup 3]. The reactor was similar to the HYAN reactor in Lakeview but without a recirculation system. A gas-solid separator was installed above a filter packed with polypropylene pall rings. The organic loading rate was increased stepwise to 30 kg chemical oxygen demand (COD)/m[sup 3][center dot]d. The hydraulic retention time was only 6 hours at the target loading rate. More than 70% of soluble COD in the influent was removed, even at an organic loading as high as 30 kg COD/m[sup 3][center dot]d. Soluble 5-day biochemical oxygen demand (BOD[sub 5]) removal efficiency at the loading rate exceeded 95%. Volatile fatty acids concentration in the effluent was consistently less than 60 mg/L after the day when stable treatment had been obtained. The methane production fluctuated between 0.3 and 0.4 L/g COD removed. The inside of the reactor consisted of two zones, a sludge blanket zone with less than 1% solids concentration and a sludge bed zone with 4-7% solids concentration. Although the reactor was seeded with an anaerobically digested sludge, granular sludge was produced in the reactor. The ratio of granules to the solids remaining in the reactor increased to approximately 70% at the end of the experiments. Most of the granules had diameters of less than 1 mm and their settling velocity was 0.6 cm/s or more. The granules were composed of bacteria like Methanothrix according to SEM observations. The methane production rate was between 0.8 and 1.1 kg methane as COD/kg SS[center dot]d in an acetate solution. According to substrates distribution in the reactor and tracer tests, the bed zone in the reactor worked similarly to a continuously stirred tank reactor (CSTR). Evaluation of soluble COD removal rates in the reactor indicated that the rate could be simulated by a Monod type reaction. 10 refs., 12 figs., 8 tabs.

OSTI ID:
6507663
Journal Information:
Water Environment Research; (United States), Journal Name: Water Environment Research; (United States) Vol. 65:1; ISSN 1061-4303; ISSN WAERED
Country of Publication:
United States
Language:
English

Similar Records

Utilization of high-strength wastewater for the production of biogas as a renewable energy source using hybrid upflow anaerobic sludge blanket (HUASB) reactor
Conference · Wed Jul 01 00:00:00 EDT 1998 · OSTI ID:20002737

Granulation of biomass in thermophilic upflow anaerobic sludge blanket reactors treating acidified wastewaters
Journal Article · Thu May 01 00:00:00 EDT 1986 · Biotechnol. Bioeng.; (United States) · OSTI ID:5261199

Feasibility of expanded granular sludge bed reactors for the anaerobic treatment of low-strength soluble wastewaters
Journal Article · Fri Aug 05 00:00:00 EDT 1994 · Biotechnology and Bioengineering; (United States) · OSTI ID:7243061