Often used in spas, Bromine is an effective sanitizer that is more convenient than chlorine, if you don’t mind the extra cost. Water does not require as much testing and is more stable than chlorine, meaning it stays balanced for a longer period of time. Bromine can be used with an automatic feeder as chlorine can, but does not have the potential of raising CYA levels. CYA or cyanuric acid is used in automatic feeders in order to protect chlorine against UV rays. The UV rays in sunlight cause a “burn-off” effect, reducing the effectiveness of chlorine. Protecting it ensures the chlorine will remain effective at relatively low doses.
Persulphates work in much the same way as Chlorine. They kill bacteria and break down bather waste but they are not very effective against algae. You always need some other product to kill algae if you use Persulphates. They are often referred to as 'Active Oxygen' systems. This trips off the tongue better than potasium monopersulphate and sounds more space age.
Stabilized Hydrogen Peroxide has been tested in two municipal pilot projects (a third is underway) under terms of reference approved by the respective Ministries of the Environment in Killaloe ON and Sunnyside NL. Townspeople are thrilled with their new healthy water free of the taste and odours from chlorine, and pleased with related reduced DBPs. The treated water met the objectives of the respective Ministries in terms of Health Canada compliance requirements.
In fact, Mayor Robert Snook of Sunnyside said, “We feel relief to be speaking of our water with pride rather than apology”.
Reading many of the comments, this was also my first thought.
You can send out water that may be absolutely sterile, great, but the first leak/underpressure/break/cross connection/backflow or combination thereof event you have, now your whole system is contaminated, and worse you have no standard residual to test for to find unaffected areas, so may as well consider the entire system contaminated.
At that point you come full circle because you have to flush and sanitize with a persistent disinfectant anyway to restore service.
At my plant, we clorinate just prior to filter influent and maintain a minimal residual to ensure our rapid sand filters aren't biological, then after clearwell detention it's hit with Trojan Swift UV-C reactor treatment, then directly after that the finished effluent is hit with chlorine gas injection right before entering the distribution system, and we usually try to maintain our free residual at 2-2.75ppm to last all the way out to the dead ends of our aging system.
Nature seems to have the best answer for the last 3 billion years. All compounds are held together with a single electron in their covalent bonds. Fortunately nature has a group of microbes that are RNA based life forms that have the genetic code to reduce all compounds into their elemental/nutritional state. All scientists already know that you should never use chlorine to purify water/waste water. 1.chlorine kills "Normal gut flora" in your digestive tract. This leads to weak immune systems. Cancer, diabetes, asthma, etc. Next major problem chlorine will only kill microbes within its ph range. Anything outside of that will accumulate with no natural predators. (microbially speaking). The name of this Kingdom, Group, Species is Archaea. Available online. archaeaproducts.squarespace.com
It's still chlorine, but we use Miox, mixed oxidant, which we generate at the plant from salt. Much safer than ton cylinders, more effective, and solves a lot of problems associated with chlorine gas use.
Why do we still use chlorine? Because there is nothing else that will do the job at this time in history. One day we will find something else to guarantee safe disinfected water, but not yet.
Our best choice away from gas chlorine, (thankful after being gassed a few times myself) is to generate a mixed oxidant out of salt and water. This is a mild bleach with several forms of chlorine including chlorine dioxide. We went to this to increase our residuals in the tanks, reduce TTHM's, and provide better water quality for our customers. I'm very happy with it as it not only does a great job out in the system, but controls taste and odors coming from the river we withdraw from, which can get nasty at times.
This system is a whole lot safer than gas chlorine. Tastes much better than it as well. If your customers do not like the taste of chlorine, I'd recomend a carbon filter to further reduce contaminants as well as taste and odors. Maybe our customers need to be a little more proactive on their end, instead of totally relying on others for everything.
I had a lot of success switching a treatment system from chlorine to hydrogen peroxide. The benefits were more effective treatment, lower cost product (1/12), reduced chemical requirements (10%) and enhanced safety. The plant was having issues with its heating system as a result of chlorine, and the staff was poisoning their atmosphere. OH&S was very happy with the results of my design change
Nature has the best water cleaning process. Man has not made or invented anything that comes close. Chlorine kills microbes and people. The microbes are responsible for the digestive process. Nature has DNA and RNA based microbial groups. DNA bacteria and fungi breakdown simple compounds. But they do not have the genetic code to breakdown compounds into their elemental state. The RNA microbes do. This why all waste waters when cleaned with RNA microbes are declared potable. E.coli can not exist. Their count is always zero. Very inexpensive to use. Examine one E.coli cabbage recall and do the math.
Chlorine use in water treatment with filtration and sanitation of watewater are one of the single greatest leaps forward in improving life expectancy next to vaccinations. The water born diseases that used to affect thousands or hundreds thousands of Canadians, Americans, and other nations with the premature deaths of children drastically lowering the chances of reaching adulthood should never be forgotten. Simply look at developing nations and know there is a reason why the methods are in place that we have. Anyone fear mongering about chlorine should remember people only live as long as they do now because of sanitation of water, wastewater, and vaccines and there is a reason chlorine has always been used. Anyone complaining of cancer at 70 or 80 at least got to live to 70 or 80 instead of dying at 5 years old or younger which accounted for a serious part of our nations mortality rates 80 years ago. Cholera, Dysentery, Polio, etc, etc the list goes on.. all water born diseases.
Now that being said PH control and maintaining appropriate residuals with chlorine with removal of DBP precursors is the tried and true method and totally agree brine sodium hypochlorite electrolysis generators are the best way to go. If you have high organics than enhanced coagulation is required to remove THM precursors and DBPs. However everythring depends on the source water of the community, what works one place is not going to work at another. Ozone still produces DPBs, there is UV but there are no residuals. Bromine produces just as many bad DBPs, but they are not as studied or regulated because chlorine is the predominantly used chemical in water and wastewater treatment for its effectiveness. As for the leaching of metals, PH control and corrosion control should always be a part of a communities water treatment plan, especially older systems. You need neutral stable water, high alkalinity to get a scale film on the inside of pipes. The building codes over the last 100 years alone and the various types of infastructure used should make this obvious. CGDWQ requires corrosion control which is why the PH range is 7 to 10.5 to end of distribution to stop the leaching of lead and copper. Contamination of the distribution system is vital to protecting a community, you can have the worlds best water treatment methods and still make people sick or kill them not maintaining your distribution system. Our community has 52 different pumping zone elevations with one of the most complicated distribution systems in North America, you have no idea what is going on inside of those pipes, at customers homes, infiltration, broken pipes, does your community have sufficent cross conection bylaws and enforcement in place? You simply have no clue as to whats underground and the older your community is the more that holds true. I turn on the water in my community knowing my childs not going to die and the residual chlorine needed is in such small quatities its negligable when dosed correctly. Also everyone here is aware that chlorine disipates over time right? If you are that concerned over less than 2ppm of residual or less, simply pour a jug of water and leave it out in your fridge open to atmosphere.