Document Type

Dissertation - Open Access

Award Date


Degree Name

Master of Science (MS)


Civil Engineering


Both anaerobic and aerobic treatment of wastewater has been used for many years. Some of the common aerobic treatment systems include oxidation or stabilization ponds, activated sludge, trickling filters, and aerated lagoons. Anaerobic treatment has been most commonly used for digestion of sewage sludge. However, septic tanks, anaerobic lagoons, and anaerobic activated sludge (contact stabilization) units are used to treat wastewater anaerobically. More recently, the two systems have been used in combination, with the anaerobic system preceding the aerobic one. This type of treatment has been used primarily for lagooning of industrial wastes, and most commonly for meat-packing wastes. In all instances, the anaerobic unit of combination systems has been designed to provide some waste stabilization, that is, to remove a portion of the BOD, biochemical oxygen demand, of the waste. This requires the relatively long detention time which is characteristic of anaerobic treatment. The aerobic unit serves to reduce the remaining BOD of the waste to a level dictated by government regulation or by the capacity of the receiving stream to handle the organic load. The advantages and uses of this type of combination treatment could be many. Rather than adding a more expensive aerobic unit to an overloaded aerobic waste treatment system, anaerobic pretreatment, such as that provided in a simple septic tank, might make the existing system perform satisfactorily. In the design of a new system, the initial construction cost could be cut if the size of the aerobic unit required to handle the wastewater could be substantially reduced by anaerobic pretreatment.

Library of Congress Subject Headings

Milk -- Microbiology



Number of Pages



South Dakota State University