Its necessary to reasonably blunt about the technologies of desal and its daughter tech RO. Both are indeed highly destructive to their discharge environments. RO is highly inefficient, discharging a residual very high brine of 40 to 60% of intake. The older larger RO facilities are even less efficient. And as RO is predominantly inland, their discharge is usually designed to be into wells deeper than their intakes and anywhere up to a Km from the intake. The critical problems for RO discharge are: 1. assuming the cheapest extraction is from the shallower unconfined aquifer , by discharging deeper below intake, you are discharging into the confined aquifers at a lower level; these deeper confined aquifers are often the best potable water resource , so 2. effectively you are dumping into others water supply, or 3. indeed you are contaminating the regions long term water supplies that are hydrating the earths crust with brine. Brine ascent through the soils to the surface via the evaporation process, thus long term you add to the devastating permanent contamination of productive agricultural land. RO has also a heavy carbon footprint due to its energy needs, its high consumables of filtration and chemical additives and the need for manpower attendance usually 24/7. That's the main damage of RO. As for desal. People have correctly suggested their discharge is a problem even when regulated. Infact from experience most discharges regulations are not complied with, as it has to be dumped if the desal operation is to operate. Similar to pure RO, the residual discharge can be anywhere between 40 and 60% dependent upon the age of the system. This all goes into the shoreline. The damages include: a rise in local sea temperature by between 1/4 and 3/4 a degree along with potential tripling the saline ppm . The effect is bleaching of coastline corrals, with the knock on effect of killing off the shoreline eco system, ie fisheries, shell fish/ crustaceans, pearls, which long term effects offshore sea life and the reliant birds and onshore eco system. Interestingly the rise in the residual high mineral brine and rise in temp encourages the red algae, which blocks the desal intakes. Karma? Remember we are not discussing only today or the next 20 years but the 100 years long term sustainability of our eco systems and the present strategy damage of employing and creating a reliance upon more and more desal and RO facilities. Ok so that's the knocking of the presently technology and the recommendation that in fact it ought be phased out! rather than expanded. But we should not suggest this IF we dont have alternatives. We do, and with no buts, we could almost eliminate RO now, by employing different strategies. Sorry , there is a but, but there is such a commercial industry built up around RO especially when we are losing our natural potable resources, that to suggest phasing them out would be political suicide. So how we are asked. Here a few headings. 1. Correct management of Diversification of water usage ie the right water for the right purpose. 2. Alternative water extraction from the atmosphere. The existing tech with a modified business model, minimizing its consumables simply needs to improve capacity. 3. Restructuring the present grossly mismanaged water resources 4. Education and redesign of home water usage 5. STOP polluting our existing water resources on surface and below ground eliminating the need for RO. Did you know that outside of the extreme arid desert regions, where we should actually be living anyway, most communities and cities, villages once had their own private water resources in the forms of ponds, dykes, canals and leats, lakes, nearly ALL neglected, abandoned or abused, contaminated, therefore disused since centralised reservoirs were introduced with new infrastructure piping to abodes. That infrastructure from the reservoirs has also not been maintained. Consequently more and more wells and bore wells are dug, sucking the potable water aquifers dry. thus the present proliferation of RO and demand for desalination. a vicious circle of decline. The complexity of solution can be further discussed. The solutions exist.
Published by Garry de la Pomerai, DRR Consultant 'SOLUZION Environmental Services'. Dubai. UK.
Its necessary to reasonably blunt about the technologies of desal and its daughter tech RO. Both are indeed highly destructive to their discharge environments. RO is highly inefficient, discharging a residual very high brine of 40 to 60% of intake. The older larger RO facilities are even less efficient. And as RO is predominantly inland, their discharge is usually designed to be into wells deeper than their intakes and anywhere up to a Km from the intake. The critical problems for RO discharge are: 1. assuming the cheapest extraction is from the shallower unconfined aquifer , by discharging deeper below intake, you are discharging into the confined aquifers at a lower level; these deeper confined aquifers are often the best potable water resource , so 2. effectively you are dumping into others water supply, or 3. indeed you are contaminating the regions long term water supplies that are hydrating the earths crust with brine. Brine ascent through the soils to the surface via the evaporation process, thus long term you add to the devastating permanent contamination of productive agricultural land. RO has also a heavy carbon footprint due to its energy needs, its high consumables of filtration and chemical additives and the need for manpower attendance usually 24/7. That's the main damage of RO.
As for desal. People have correctly suggested their discharge is a problem even when regulated. Infact from experience most discharges regulations are not complied with, as it has to be dumped if the desal operation is to operate. Similar to pure RO, the residual discharge can be anywhere between 40 and 60% dependent upon the age of the system. This all goes into the shoreline. The damages include: a rise in local sea temperature by between 1/4 and 3/4 a degree along with potential tripling the saline ppm . The effect is bleaching of coastline corrals, with the knock on effect of killing off the shoreline eco system, ie fisheries, shell fish/ crustaceans, pearls, which long term effects offshore sea life and the reliant birds and onshore eco system. Interestingly the rise in the residual high mineral brine and rise in temp encourages the red algae, which blocks the desal intakes. Karma? Remember we are not discussing only today or the next 20 years but the 100 years long term sustainability of our eco systems and the present strategy damage of employing and creating a reliance upon more and more desal and RO facilities.
Ok so that's the knocking of the presently technology and the recommendation that in fact it ought be phased out! rather than expanded. But we should not suggest this IF we dont have alternatives. We do, and with no buts, we could almost eliminate RO now, by employing different strategies. Sorry , there is a but, but there is such a commercial industry built up around RO especially when we are losing our natural potable resources, that to suggest phasing them out would be political suicide. So how we are asked. Here a few headings. 1. Correct management of Diversification of water usage ie the right water for the right purpose. 2. Alternative water extraction from the atmosphere. The existing tech with a modified business model, minimizing its consumables simply needs to improve capacity. 3. Restructuring the present grossly mismanaged water resources 4. Education and redesign of home water usage 5. STOP polluting our existing water resources on surface and below ground eliminating the need for RO.
Did you know that outside of the extreme arid desert regions, where we should actually be living anyway, most communities and cities, villages once had their own private water resources in the forms of ponds, dykes, canals and leats, lakes, nearly ALL neglected, abandoned or abused, contaminated, therefore disused since centralised reservoirs were introduced with new infrastructure piping to abodes. That infrastructure from the reservoirs has also not been maintained. Consequently more and more wells and bore wells are dug, sucking the potable water aquifers dry. thus the present proliferation of RO and demand for desalination. a vicious circle of decline. The complexity of solution can be further discussed. The solutions exist.