An interdisciplinary approach to topics in biological wastewater treatment

Developing effective biological wastewater treatment systems for rural, less developed areas is a continuing challenge because availability of resources is often limited. At issue is system performance and benefit. Therefore, it is necessary that an interdisciplinary systems approach be utilized when addressing these complex challenges. The scope of this research involves evaluation of the sequencing batch reactor (SBR) as the focal point in a system of treatment components for use in rural settings. The SBR was first evaluated for its appropriateness as a treatment system for a rural condition. Its performance was found to be excellent using minimal energy and operational inputs. It was also found to demonstrate biological nutrient and pathogenic removal. Secondly, the SBR was used as the biological treatment component in a series of studies examining the potential benefits to a rural area that could be recovered from the treatment process. In these studies, the SBR was coupled with a polyculture constructed wetland to evaluate overall treatment performance and the potential benefit of wildlife habitat creation. The SBR/Wetland system couple demonstrated excellent treatment performance while sustaining a reasonable diversity of aquatic species following the first season of operation. The SBR was also evaluated for its role in providing an inorganic nutrient fertilization source for an aquaculture component. The result showed that the SBR could be operated such that nutrient ratios acceptable for fertilization of a planktivorous pond culturing were within acceptable ranges. The resulting ecological response of the system demonstrated that the bottom-up controls could sustain the zooplankton population levels necessary for larval planktivorous fish production. Finally, the SBR was evaluated as an applied research tool to simulate full-scale continuous plug-flow activated sludge treatment systems. In these studies, it was found that a bench-scale SBR adequately simulated the performance and dynamic response of a full-scale plug-flow system. The resulting benefit is that operation and performance of full-scale systems responding to process modifications can be assessed prior to full-scale implementation.