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

Wastewater treatment is a huge industryworldwide. Despite the massive capital andoperating costs, only a relatively small amountof R&D investment is made. This might havebeen related to the limited demands in terms ofeffluent quality in the past, but today'senvironmental awareness requires much strictereffluent standards to be achieved. This inturn 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 gapsto be filled and substantial benefits could begained from this.A range of knowledge gaps are identified inthis paper, extending from the role ofintermediates in nutrient removal overparameter estimation in modelling andsimulation to understanding the microbialmetabolic pathways at a genetic and enzymaticlevel. These gaps are opportunities andchallenges for all researchers andprofessionals in this field. Addressing themwill help substantially in the continuingdevelopment of wastewater treatmenttechnologies.The complexity of biological wastewatertreatment processes requires a broad range oftools and expertise to address the knowledgegaps. Novel process analysis tools arecritically important to investigate biologicaltreatment processes in future. They will comefrom different expertise areas and will need tobe used in close integration to gain maximalbenefits from the efforts. These tools willlikely include respirometry, novel chemicalanalyses, microsensors, gene-basedidentification, microbial physiology techniquesand integrated modelling and simulation. Examples of the application of such techniquesare provided to demonstrate the way thesetechniques may be used in future. In the nextfew years, there is likely an exciting andhighly interactive period of research anddevelopment for the wastewater industry.