On May 20, 2013, Kyle McGonigle was on a dock on Kentucky's Rough River Lake. A dog swimming nearby yelped, and McGonigle, 36, saw that it was struggling to stay above water. He dove in to save the dog, but both he and the animal drowned, victims of electric-shock drowning (ESD). Cords plugged into an outlet on the dock had slipped into the water and electrified it.
You have successfully negotiated free fall, deployed your canopy, and are about to touch down. Safe? Nope. Inexperienced solo jumpers trying to avoid an obstacle at the last minute, or experienced skydivers looking for a thrill, might sometimes pull a toggle and enter a low-hook turn. "If you make that turn too low, your parachute doesn't have time to level out," says Nancy Koreen of the United States Parachute Association. Instead, with your weight far out from the canopy, you'll swing down like a wrecking ball.
Electrodeionization: Water is passed between a positive electrode and a negative electrode. Ion exchange membranes allow only positive ions to migrate from the treated water toward the negative electrode and only negative ions toward the positive electrode. High purity deionized water is produced continuously, similar to ion exchange treatment. Complete removal of ions from water is possible if the right conditions are met. The water is normally pre-treated with a reverse osmosis unit to remove non-ionic organic contaminants, and with gas transfer membranes to remove carbon dioxide. A water recovery of 99% is possible if the concentrate stream is fed to the RO inlet.
The desalinated water purity is a function of the feed water salinity, membrane selection and recovery ratio. To achieve higher purity a second pass can be added which generally requires re-pumping. Purity expressed as total dissolved solids typically varies from 100 to 400 parts per million (ppm or mg/litre)on a seawater feed. A level of 500 ppm is generally accepted as the upper limit for drinking water, while the US Food and Drug Administration classifies mineral water as water containing at least 250 ppm.
It’s extremely important to confirm your water has been purified or treated before drinking. If your water is contaminated and you don’t have bottled water, there are various water purification methods that are used today, and each method has its merits and demerits. Filtering is good for basic water tasks such as sediment and chlorine removal, but in the long run reverse osmosis is the best option. At Schultz Soft Water we focus on reverse osmosis units because they require a lot less energy and time required to make water versus distillation.
Compared to reverse osmosis, filtration is considered effective when it comes to selective elimination of much smaller molecular compounds such as chlorine and pesticides. The other factor that makes filtration less costly is that it does not require a lot of energy needed in distillation and reverse osmosis. It is an economic method of water purification because little water is lost during purification.
Most reverse osmosis systems require you to do a bit of under-sink installation and drill a hole for a separate dispenser, but you can also opt for a countertop model that saves your cabinet space and won’t require any drilling. The APEC Portable Countertop Reverse Osmosis Water Filter System can be set up quickly and easily with no permanent installation necessary.
Energy-recovery pump: a reciprocating piston pump having the pressurized concentrate flow applied to one side of each piston to help drive the membrane feed flow from the opposite side. These are the simplest energy recovery devices to apply, combining the high pressure pump and energy recovery in a single self-regulating unit. These are widely used on smaller low-energy systems. They are capable of 3 kWh/m3 or less energy consumption.
Coagulation and flocculation are often the first steps in water treatment. Chemicals with a positive charge are added to the water. The positive charge of these chemicals neutralizes the negative charge of dirt and other dissolved particles in the water. When this occurs, the particles bind with the chemicals and form larger particles, called floc.
The other half of the tag team is to eliminate pollutants. The best way to do this is with a homemade carbon filter. This uses the same technology as Brita filters. Carbon is a chemically active substance, with a tendency to bind to most anything. At a microscopic level, charcoal is a heavily pitted and striated material, which vastly increases its real surface area. The result is that when water slowly runs over charcoal, pollutants find themselves glued to the charcoal surface. An improvised filter can be made out of ground-up charcoal, a strainer and a funnel. Bear Gryllis made a purification drinking straw out of little more than a reed and some charcoal bits for the Discovery Channel's "Man vs. Wild." It's a simple technique, but it is highly effective.
The first part of the purification tag team must eliminate microorganisms, like harmful bacteria and parasites. There are a handful of tried and true methods for doing this. The most familiar is boiling. Simply bringing water up to its boiling point of 212 degrees Fahrenheit will kill almost all microorganisms, so just a few minutes of boiling will do the job.