The application of rapid sand filtration combined with front-end aeration forms a robust barrier in the removal of ammonium, iron and/or manganese from (ground)water. Rapid filtration systems are applied at a large number of drinking water production sites.
A project within the Dutch water sector’s joint research programme (BTO) has been initiated to collect information and enhance insight into these rapid filtration systems. The objective is to analyse and subsequently optimise filter operation and design by modelling the removal mechanisms. At present, the developed model can predict the water quality of the filtrate on the basis of feed water quality and of parameters that characterize filter process conditions and filter material characteristics. However, analysis and optimisation of these filtration processes for drinking water production are hampered by the complexity of the current model and lack of a user-friendly interface. The objective of this project is tackle these limitations by developing a user-friendly tool and modify the current model such that analysis and assessment of failure mechanisms in these filters are improved.
Development of a user-friendly software tool
The development of the user-friendly tool involves the further development of both the front-end and back-end of the current tool. Regarding the back-end, we collect water quality parameters of different groundwater types, rapid filtration and drinking water production data, and store this in a database. We model the influence of filter back-washing and the (re)growth of adsorptive material by iron and manganese oxides on filter media grains. The front-end is developed after we make an inventory of user requirements. The tool will be delivered with a manual.
A developed version of the tool will be evaluated by a group of specialists of participating water companies. This group also advises on the prioritisation of back-end and research activities.
The tool will be demonstrated during a workshop with Dutch drinking water specialists. Research findings and the accompanying manual will be summarised in a BTO technical report.
Analysis and optimisation of rapid filtration processes
This project aims to bring together and translate years of (BTO) research, practical experience and knowledge into a tool that water companies can apply to address questions regarding operation and design of the rapid filtration step. The Rapid Filtration Engineering Assistant enables the assessment of current filter operation and design, analysis of optimisation strategies, and provides pointers for troubleshooting. Additionally, the tool can be used to train production site operators through a virtual simulation environment in which possible effects of different operational settings can be safely tested.
Simulation of the concentration of iron (Fe+2, left diagram, blue line) and manganese (Mn+2, right diagram, blue line) in a cross-section of a rapid filter (distance measured from the bottom of the rapid filter is depicted on the vertical axis), over a four-day period after the filter has been back-washed. The top of the filter bed is represented by a solid black line, the supernatant water level with a dashed line. Measurements are shown as grey markers.