How Much of an Advantage Can Anaerobic Technologies Provide?

Abstract

Many publications have stated that use of anaerobic processes for liquid treatment at wastewater treatment plants can provide several significant advantages over aerobic treatment. These advantages include lower operating costs, reduced energy demands, increased biogas production with potential for power generation, lower sludge production, simpler operation, and a smaller footprint. However, few of these publications have attempted to quantify these advantages and compare them to conventional aerobic processes, particularly for the treatment of municipal strength wastewaters. This paper compares several anaerobic technologies to a traditional aerobic municipal wastewater plant designed to remove carbon, solids, and nutrients to quantify and compare sludge production, footprint, energy requirements, costs, and green house gas production. It is shown that anaerobic technologies do offer advantages of reduced footprint, reduced sludge production, and reduced energy requirements. However, in terms of cost, the traditional aerobic process is most attractive when having to meet nutrient limits.

Anaerobic Processes

“…More generally, Rudelle et al (2011) examined the natural pretreatment processes of sewage water transmission, and found that of the three steps examined (hydrolysis, fermentation, and sulfate reduction), hydrolysis is the limiting step of the degradation of the sewage waste. Stone and Reardon (2011) found that anaerobic systems are more desirable as treatment streams for the removal of carbon, solids, and nutrients when compared to aerobic systems because anaerobic processes have smaller footprints, less sludge produced, and lower energy requirements.…”