Innovative Water Management
Re–Circulation and Re–Use: How Smart Water Comes to Life
The basic prerequisite for water recycling is the establishment of an efficient water management system to separate water that readily lends itself to recycling from water that is less suitable. Most of these internal recycling processes are located at or near the source where the complexity of the constituents is limited and additive techniques can be deployed with minimum effort and expense.
The integrated energy supplier, Suncor Energy, recycles more than 90 per cent of the water contained in steam, which the company uses to extract oil from oil sand. Instead of storing injection steam in underground disposal wells, recycled saline water is treated, the salts and solids are filtered out and the water is reused to produce steam again. This approach minimizes the extraction of ground water.
Water is Especially Valued in the Desert
What Wabag is currently doing is another example. At the beginning of 2014, the company was awarded a contract to build a wastewater treatment plant at the new industrial park in the city of Al Kharj, Saudi Arabia.
Effluents from various production facilities at the site will be treated to the maximum extent possible and will be reused as process water. The various stages in the purification process include mechanical pre-treatment, chemical precipitation, sedimentation, retention basin, biological purification, filtration, activated charcoal filters and disinfection. The plant will have a capacity of 10,000 m3/d.
Zero Liquid Discharge - the Model for the Future?
Instead of purifying water prior to discharge, would it make more sense to eliminate water discharge altogether? Elimination of effluent from production (zero liquid discharge) is currently the subject of a highly controversial debate. About 400 plants are already operating around the world.
The motives can be different, for example elimination of dependency on the local water supply particularly in regions where water is scarce, stringent environmental regulations for salt concentrations in effluents, recovery of re-usable substances or image enhancement. Experience shows that the approval process for zero liquid discharge plants is often simpler and faster, which is another interesting aspect.