Anaerobic sludge digestion operations manual

OPERATIONS MANUAL ANAEROBIC SLUDGE DIGESTION Included in this manual are comments solicited from treatment plant operators throughout the country on the operation, control and troubleshooting of anae- robic sludge digesters. Major contributions are also included from scientists and engineers. NOTES To order single copies this publication, MO, "Operations Manual Anaerobic Sludge Digestion", Write to: General Services Administration (8BRC) Centralized Mailing Lists Services Building 41, Denver Federal Center Denver, Colorado Pleas© indicate the MO number and title of publication. STARTING AN ANAEROBIC DIGESTER The best way to start a digester is by using seed sludge from a unit which is already operating satisfac torily. Seed quantities varying from 50 to 75 percent by volume of the raw sludge feed will allow an almost im mediate start in the range of normal digestion if proper temperatures have been obtained (Figure 25) and adeCreated Date: Z.

Advantages/Disadvantages of Anaerobic Digestion •Advantages Can accept high strength wastes Useful end product-CH 4 Lower cell yield-less residual sludge • BOD removal about lbs of biomass per lb of BOD • AD about lb/lb Lower N/P requirements •Disadvantages Optimum temperature requires heat input Presence of oxidizing. Anaerobic digestion of sludge is usually applied without recycling the thickened, digested sludge because the residence time and the sludge’s initial OM concentration allow to synthesise bacterial flora without any danger of leaching. Gas output is the most representative and simple criterion for assessing the quality of the digestion. It mainly depends on three factors. In India, anaerobic digestion has been practiced for years using different substrates, including sewerage sludge. The “Manual on Sewerage and Sewage Treatment Part A: Engineering” published by the Central Public Health and Environmental Engineering Organisation (CPHEEO ) provides details regarding the recommended designs and technical aspects for the construction of anaerobic digesters in the country.

The energy requirements of anaerobic sludge digestion consists of mixing and pumping, The These digesters operate in the mesophilic temperature range. Throughout the manuals of unit processes of waste-water treatment it will to health, e.g. by anaerobic digestion or lime conditioning;. The corbels limit the downward movement of the digester cover and protect the internal equipment from damage if sludge is withdrawn below the designed operating.