ENVIRONMENTAL ENGINEERING
UNIVERSE Knowledge educational article.
Water treatment is usually a sequence of processes rather than a single filter. Engineers select and combine processes according to the contaminants, water chemistry, required quality and operating constraints.
Large debris can be removed using screens. Sedimentation then allows suspended particles to settle under gravity when conditions are suitable.
Filters physically retain particles as water passes through a porous medium. The effectiveness depends on pore structure, flow conditions, particle properties and filter operation.
Materials such as activated carbon can adsorb certain dissolved organic compounds and improve taste and odour. This is different from simple mechanical straining.
Disinfection aims to reduce harmful microorganisms. Methods include appropriately controlled chlorination, ultraviolet treatment and other processes depending on the system.
A treatment system must consider flow rate, pressure loss, maintenance, energy, cost, contaminant levels and monitoring. Good design therefore treats water quality as a systems-engineering problem.