6 months ago

Seccua Home Solutions

Seccua Brochure including all information you need to select the right water treatment technology for your home

Water Treatment 101

Water Treatment 101 Reverse Osmosis (RO): Frequently asked questions How much water does RO consume? Conventional reverse osmosis equipment used in domestic settings consume up to 4 liters of water to produce one liter of drinking water. The waste water is discarded into the sink. Does RO remove pathogens? RO is a process developed for removed dissolved components from the water in industrial and large municipal plants, not at home. Formation of biofilm on the RO membrane is a typical issue occurring in RO systems. Bacteria living in a biofilm produce slime, which they use to store nutrients and for purpose of protection. This increase concentration of nutrients leads to an increase transport of such substances through the membrane. RO membranes also show production defects, which consist from micro-holes in the polymer-coating of the membrane, so called „pin-holes“, just large enough to let bacteria pass through the membranes. EPA does not rate RO as a disinfection technology. What happens in a RO system, if I don’t use any water? At no flow, the concentrated water on the inlet-side of the RO is no longer removed. Scaling of minerals occurs, destroying the function of the membrane. Most RO systems have such a low flow, that they need to produce water into a pressurised storage tank, from which it is then provided to consumer. Those pressurised tanks use a rubber bladder, filled with air, placed inside a pressure-housing from metal. Rubber is perfect for bacteria to grow upon. What substances does RO remove? The following substances are held back: • hardness • salts (sodium chloride and other) • metal ions What is not sufficiently retained? The following substances are not sufficiently retained: • pesticides • substances with hormone-like effects • drug residues • bacteria (including pathogens) • chlorine (destroys the membrane) 14

Cryptosporidia, leaving their protective cysts, entering a human’s vascular system through the intestine’s wall. Water Treatment 101 Chlorine and UV treatment UV Radiation Ultraviolett (UV) light is often used to „de-activate“ DNA of bacteria present in drinking-water. „De-activation“ is hereby used as a term for damaging the DNA of bacteria, so they cannot replicate. The bacteria themselves remain in the water, alive. It is known that if bacteria are not exposed to a sufficiently high UV-dose, such damage will heal. UV for 10 gpm flow typically consumes between 200 to 400 Watt of power continuously. UV is not suitable for being turned on and off instantly, since it requires several seconds for the lamps to warm up and become effective. If water is standing inside a UV-reactor without flow, the water heats up quickly. In a UV-reactor, water is flowing alongside a UVlamp, mounted inside a steel-pipe. The costly lamp needs to be exchanged annually. UV systems should be certified to US EPA or German DVGW standards. If the water contains particles, even if those are not visible, UV-light cannot reach the bacteria at all or with a high enough dose. Normal UV-systems also do not work against parasites like Cryptosporidia or Cysts, since their light cannot penetrate through the shell of those micro-organisms. They also do not work against virus, since it takes much higher UV-doses to damage a virus’ DNA. Chlorination Disinfection of drinking water by the means of chlorine is typically achieved by dosing Sodium-Hypochlorite („bleach“) into water, which creates an equilibrium of hydrochloric acid and chlorine. Water from wells, springs or from surface intakes usually contains humic substances, aka color. Color and chlorine react to carcinogenic „Disinfection-By- Products“ (DBP). DBPs, not chlorine, create the typical smell of chlorinated water. Chlorination should only be added to water after color and suspended solids have been removed. US EPA requires filtration Water from shallow wells, from wells in rocky areas or from mountain springs is considered to be under the potential influence of surface water. For such types of wells and for direct surface water intakes from lakes or creeks, Drinking Water Guidelines, like released by the US EPA, require bacteria and parasites to be removed by filtration at a removal rate of greater than 99,99%. 15