Anaerobic Treatment of Pulp and Paper Mill Wastewaters, 1993 China Paper Conference Proceedings

J. Lee

Stabilization of biodegradable organics with anaerobic processes couples waste treatment (an expense) with energy production (a credit), offering the rare opportunity for potentially positive return on a waste treatment capital investment, as well as minimized operating costs. Both the characteristics and quantity of biodegradable organic compounds in pulp and paper mill effluents make anaerobic treatment an economically attractive alternative to aerobic treatment processes that have been traditionally employed.

Anaerobic digestion of municipal sewage sludge has been practiced routinely since the 1930s. Until the present decade, however, anaerobic treatment of industrial wastewaters has been limited primarily to the poultry and red meat packing and vegetable processing industries. Anaerobic lagoons were first used in Australia in 1940, but found little full-scale application to food processing or other industrial wastes in the United States until 1955.

The potential to treat anaerobically high strength, readily degradable organic wastes has long been recognized in theory, if not in practice. In anaerobic processes, organics are oxidized to carbon dioxide (CO2) and reduced to methane (CH4). Since an electron acceptor (i.e., oxygen) is not provided, the energy conservation required for this simultaneous oxidation and reduction process to occur gives it several unique advantages, but also some limitations when compared to aerobic treatment.