Sustainable access to drinking water and providing usable water supply for adequate sanitation and also for irrigation based agriculture forms one of the major challenges for the global society in the 21st century. Accordingly, finding respective solutions became part of the Sustainable Development Goals (SDG 6) formulated by the United Nations in 2015. Politics shows broad interest in view of the growing population in many arid and semi-arid regions on the one side, and the loss of fresh water resources related to global warming on the other side. The clear demand for technological approaches focusing on efficient water usage and the exploitation of alternative sources led to the emphasis of this consortium activities on waste water purification as well as seawater and brackish water desalination processes. As a crucial part of a functional water resource management system, besides water distribution itself, the information processing and monitoring of the respective water filtration and refinement procedures are subject to high requirements for accuracy, real-time standards and reliability. From a system engineering point of view, major issues with respect to the corresponding complex underlying physical principles are to gain an appropriate mathematical description of the dynamic behavior combined with an adequate parameterization and knowledge about the internal state conditions of the distributed processes via intelligent sensor data evaluation in spite of external perturbations.
There remain several problems in the supervision and dynamical analysis of modern water purification and desalination processes. Irrespective of the significant social task behind saving secure and accessible water supplies, the following current technical challenges are emphasized by the consortium:
- Several advanced control and estimation concepts for water processes are reported in the literature which do not get applied to actual plants despite satisfactory simulation results. Accordingly, realistically implementable observer schemes (soft sensors) have to be developed with respect to reliable validation standards.
- Often, specific approximations of the underlying complex dynamical processes are made which concentrate on very specific conditions and fail to capture all significant influences. For applications with high safety requirements such as water treatment which directly or indirectly relates to nutrition, a reliable system description is indispensable. Thus, more accurate procedures should be enabled. Compositions of membrane, thermal and biochemical processes, as they occur in water purification, may then be treated in a unified way.
- In membrane based filtration facilities, fouling of membranes is a major challenge (especially RO). This may fully change the plant behavior and lead to complete plugging. Treating the phenomenon as a perturbation, a novel fault isolation concept for membranes shall be developed, combining the competences of the consortium. This includes to classify the membrane condition for identifying fouling early and to adapt the process control or to initiate adjustment actions.
- The overall efficiency of a water resources system is crucial with respect to distribution and energy consumption. A proper information processing unit integrated into the management system builds the basis of an optimal control scheme which may reduce the partially unacceptable high distribution losses and helps increase the applicability through better energy recovery, avoiding uneconomical operating costs.
