Medical journals on reverse osmosis water and alkaline water for health
Journal of Membrane Science
- RO filter desalination has more than half a century of industrial operation.
- Coupling this with the ability to handle a wide range of water sources makes it a strong candidate to tackle current and future water shortage problems. It is so far the most efficient technology for wastewater reclamation (tertiary treatment), and is one of the best performing technologies for desalting brackish water and sea water.
- The former is obviously a highly desirable solution in densely populated regions since it solves two problems simultaneously, namely wastewater treatment and enhancement of fresh water supply. Alongside the advancements in other aspects of RO filter technology, the development of membrane materials has undeniably made RO desalination more economic by increasing performance and efficiency. Nevertheless, the search for multifunctional membrane materials that offer higher permeability, high ion and organic contaminant rejection, and operational robustness is still ongoing. This can benefit the desalination industry by lowering the energy cost and membrane area required; simplifying pre-treatment processes; providing lower membrane maintenance costs; potentially achieving single pass RO desalination; and increasing plant capacity.
- A key limitation of commercial RO filter membranes is degradation by chlorine, which requires dechlorination of the RO feed and re-chlorination of the RO filter permeate. Furthermore, excessive pressure is required to overcome the resistance arising when membranes become fouled. The evolutionary improvement of membranes solely prepared from polymeric materials seems to be approaching saturation.
Membrane Science & Technology
- Lipopolysaccharide (LPS) endotoxin, a bacterial byproduct abundantly present in wastewater, is more and more representing a major concern in wastewater treatment sector for the potential health risk it represents. It is, therefore, more urgent than before to protect consumers from contaminating their fresh potable water reserves with LPS endotoxin through aquifer replenishment using reclaimed wastewater or by supplying reclaimed wastewater as potable water.
- Nano-filtration and reverse osmosis are the most advanced technologies used to treat wastewater to a potable level.
- In the absence of health standards related to allowable endotoxin consumption, and with a final concentration of about 100 EU.ml−1 for NF and RO permeates, subsequent of MBR, it not advisable to reuse these reclaimed waters for direct potable practices as they show a concentration much higher than that present in drinking water.
- Long-term consumption of de-mineralized water had negative health effects.
- Reverse osmosis systems use pressure to push water through tiny pores, to create “pure water.” In the process, chemicals, bacteria, and minerals are filtered through different membranes and carbon filters.
- Many reverse osmosis systems remove the good with the bad. Iron, calcium, manganese, and fluoride are a few of the beneficial chemicals that may be removed, depending on the system. Removing these essential elements from our drinking water doesn’t pose much of a problem, since a well-rounded diet will provide these as well. However, many Americans do not eat a diet that is rich in vitamins and minerals. If these people also drink demineralised water, then they are more prone to vitamin and mineral deficiency.
- Additionally, when used for cooking, demineralised water was found to cause substantial losses of all essential elements from foods such as vegetables, meat and cereals. Such losses may reach up to 60% for magnesium and calcium, 66% for copper, 70% for manganese, and 86% for cobalt. In contrast, when hard water (not treated with reverse osmosis) is used for cooking, there is minimal loss of these essential elements.
- Kids also may lose out on fluoride protection for their teeth. According to the Centers for Disease Control, drinking municipal water that contains fluoride decreases cavities in kids by up to 60%. Reverse osmosis systems may remove this fluoride, thus putting kids at increased risk for cavities.
- From an environmental perspective, household reverse osmosis units do help the environment by curbing the purchase of bottled water, and thus creating less plastic waste in our landfills. However, because household units are unable to produce much back-pressure, they may collect as little as 5-15% of the water as “pure water” for drinking. Therefore, depending on the system, for each gallon of purified water produced, between 2 to 5 gallons are wasted (sometimes more), and discarded to the septic system.
World Health Organization
- The possible adverse consequences of low mineral content water consumption are discussed in the following categories:
- Direct effects on the intestinal mucous membrane, metabolism and mineral homeostasis or other body functions.
- Little or no intake of calcium and magnesium from low-mineral water.
- Low intake of other essential elements and microelements.
- Loss of calcium, magnesium and other essential elements in prepared food.
- Possible increased dietary intake of toxic metals.
- Drinking water should contain minimum levels of certain essential minerals (and other components such as carbonates). Unfortunately, over the two past decades, little research attention has been given to the beneficial or protective effects of drinking water substances. The main focus has been on the toxicological properties of contaminants. Nevertheless, some studies have attempted to define the minimum content of essential elements or TDS in drinking water, and some countries have included requirements or guidelines for selected substances in their drinking water regulations.
- The issue is relevant not only where drinking water is obtained by desalination (if not adequately re-mineralised) but also where home treatment or central water treatment reduces the content of important minerals and low-mineral bottled water is consumed.
- Drinking water manufactured by desalination is stabilized with some minerals, but this is usually not the case for water demineralised as a result of household treatment. Even when stabilized, the final composition of some waters may not be adequate in terms of providing health benefits.
- Sufficient evidence is now available to confirm the health consequences from drinking water deficient in calcium or magnesium. Many studies show that higher water magnesium is related to decreased risks for CVD and especially for sudden death from CVD. Biological plausibility for a protective effect of magnesium is substantial, but the specificity is less evident due to the multifactorial aetiology of CVD.
- In addition to an increased risk of sudden death, it has been suggested that intake of water low in magnesium may be associated with a higher risk of motor neuronal disease, pregnancy disorders (so-called preeclampsia), sudden death in infants, and some types of cancer. Recent studies suggest that the intake of soft water, i.e. water low in calcium, is associated with a higher risk of fracture in children, certain neurodegenerative 159 diseases, pre-term birth and low weight at birth and some types of cancer. Furthermore, the possible role of water calcium in the development of CVD cannot be excluded.