Despite the significant benefits of pool chlorines in their capacity to kill hazardous bacteria, it is evident that some of the side effects can be disadvantageous. The general smell of chlorine can be overwhelmingly unpleasant, and the agent can irritate the skin and eyes. It is also has the capability to bleach some fabrics, potentially damaging clothing. Most significantly, excessive air pockets of chlorine gas that surround pools can be hazardous for peoples’ health and possibly even be carcinogenic. For these reasons, some industries have started to investigate new alternative methods to chlorine for sterilising pools. According to Smith and Monteath et al. (2006, pp. 1 - 37), ‘some of these are good alternatives, but they do not achieve the cleanliness, oxidation levels or low price that chlorine provides’.
One of the primary alternatives to chlorine in swimming pools is Bromine. Bromine is an extremely effective pool sanitiser, successfully killing harmful bacteria found in pools. The compound can only be added in one of two very specific methods – making it very expensive. As Missouri Department Of Health And Senior Services Section For Environmental Public Health, 2014 (p. 14, 15) describes; ‘For pool sanitation, bromine compounds are sold in two solid forms - a two-part system that uses a bromide salt dissolved in water and activated by addition of a separate oxidizer; and a one-part stick or tablet that contains both bromine and an oxidizer and is dispensed by an erosion-type feeder.’ Once the Bromine is in the pool, it reacts with the water to form hypobromous acid which further dissociates into hypobromite ions through the following equation;
HOBr(aq) + H2O(l) ↔ H3O+(aq) + OBr-(aq)
Figure 10: Dissociation of Hypobromous acid to form Hypobromite ions
The use of Bromine is highly advantageous in that it is a very strong sanitiser, and works slightly differently to chlorine in the way it destroys pathogens and the like. While Chlorine sanitisers react with pathogens and other bacteria in a way that renders the chlorine ineffective afterwards, Bromine sanitisers are not affected. Hence it is possible for the Bromine to continue to sanitise the pool without reducing much of its concentration in that respect. Bromine is also very popular for its resistance to relatively high temperatures, making it ideal for spa water treatment as well. The aspect making it so popular in swimming pools is the efficacy of its primary by-product as well as its original form. When bromine reacts with organic substances such as ammonia, it forms bromamines – just as chlorine reacts with organic compounds to form chloramines. It is these chloramines in most swimming pools that are responsible for much of the difficulties chlorinated pools entail, producing an unpleasant smell and irritating people’s eyes and skin (in fact it is often these chloramines that people often receive allergic reactions to) and being largely ineffective sanitisers. Bromamines...