The Best Available Technology of Water/Wastewater Treatment and Seawater Desalination: Simulation of the Open Sky Seawater Distillation

Abstract

This review suggests the concept of the best available technology of water/wastewater treatment and seawater desalina-tion which is in fact a simulation of the seawater distillation at the open sky: coagulation in salty water aerated basin/ coagulation using seawater as coagulant solution with distillation using stored solar energy followed by waterfall on a natural mountain. This natural, green, and technico-economical technology is composed of three steps: the first one is coagulation which may be achieved: 1) in salty water aerated basin (air stripping, AS; dissolved air flotation, DAF) where the raw water is “diluted” in seawater; or 2) in “conventional” coagulation using seawater as coagulant solution instead of alum/ferric salts. The first option seems to be more natural as it simulates river water dilution in seawater and the second one is more practical for “rapid” water consummation. For colloids and microorganisms’ removal, double- layer compression and charge neutralisation, as main coagulation and disinfection mechanisms, would be involved in the first and second options, respectively. Aerated basin (AS/DAF) reproduces the natural aeration to simulate healthy natural water basin. Using stored solar energy, distillation as the best liquid-solid/liquid-liquid separation process pro-vides the removal of dissolved pollutants. For well balanced calco-carbonic equilibrium, the last step of this green treatment is the waterfall on a natural mountain providing useful gases, dissolved oxygen and carbon dioxide, and min-eral salts to the water.