Technological Needs for Sustainable Water

Sustainable water technologies, besides being economic and easily manageable should avoid secondary pollution or the simple transfer of the pollutants from one stream to another. 

Water treatment technologies are often multistep processes which include  

Primary treatments. These are based mainly on physical action examples are screening, sedimentation, filtration and flotation. 

Secondary treatments. These are based on chemical and biological processes which convert the chemical structure of the constituents of wastewater to products either innocuous or less hazard examples are neutralization, precipitation, and active sludge treatment. 

Tertiary treatments.These are used to convert chemicals diflficult to convert or not converted by secondary treatments, and when more stringent water quality is required examples are active carbon adsorption, ion exchange, reverse osmosis and the AOPs. 

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