Treating water is nothing new. Long before micro-organisms were known to exist, ancient civilisations were already boiling, settling and filtering water through sand or charcoal, simply observing that it made the water better.
The nineteenth-century turning point
Understanding the link between contaminated water and epidemics changed everything. Sand filtration became widespread in urban networks, then chlorination took hold in the early twentieth century. It is probably one of the most effective public health measures ever deployed.
The membrane era
The second half of the twentieth century saw the arrival of membrane processes: microfiltration, ultrafiltration, nanofiltration and reverse osmosis. The principle changed in nature — the contaminant is no longer destroyed, it is physically separated from the water. That is what made large-scale seawater desalination possible.
Today: measuring and controlling
Current progress is less about new processes than about how they are run: in-line sensors, remote supervision, predictive maintenance. The aim is to guarantee consistent quality while reducing energy and chemical consumption.
The next step concerns emerging pollutants — pharmaceutical residues, PFAS, microplastics — which conventional treatment trains were never designed to handle.