Integrating process engineering and microbiology tools to advance activated sludge wastewater treatment research and development

Wastewater treatment is a huge industry worldwide. Despite the massive capital and operating costs, only a relatively small amount of R&D investment is made. This might have been related to the limited demands in terms of effluent quality in the past, but today's environmental awareness requires much stricter effluent standards to be achieved. This in turn should give sufficient incentives, together with the possible large cost savings, to increase the R&D activities in this field. There are certainly significant knowledge gaps to be filled and substantial benefits could be gained from this. A range of knowledge gaps are identified in this paper, extending from the role of intermediates in nutrient removal over parameter estimation in modelling and simulation to understanding the microbial metabolic pathways at a genetic and enzymatic level. These gaps are opportunities and challenges for all researchers and professionals in this field. Addressing them will help substantially in the continuing development of wastewater treatment technologies. The complexity of biological wastewater treatment processes requires a broad range of tools and expertise to address the knowledge gaps. Novel process analysis tools are critically important to investigate biological treatment processes in future. They will come from different expertise areas and will need to be used in close integration to gain maximal benefits from the efforts. These tools will likely include respirometry, novel chemical analyses, microsensors, gene-based identification, microbial physiology techniques and integrated modelling and simulation. Examples of the application of such techniques are provided to demonstrate the way these techniques may be used in future. In the next few years, there is likely an exciting and highly interactive period of research and development for the wastewater industry. © 2002 Kluwer Academic Publishers.