Analys av vattenkvalitet i ett kommunalt badhus

Sammanfattning

Bath has been a part of human history for a long time. Today bathing/swimming in

municipal pools is for people of all ages and it is possible to take swimming courses,

exercise or enjoy recreation. The municipal indoor pool of Hogdalen in Sweden was

build in the sixties and has had problems with high levels of heterotrophic bacteria. The

facility has two larger pools, one adventure park for young kids, two smaller bath tubs

and a jacuzzi. To improve water quality UV light and coal filter were installed in

October 2009 to the already existing purification system. The water purification starts

with a mechanical grid followed by flocculation and then through a sand filter before

pH adjustment and chlorine. To adjust water levels in the pools drinking water is added

when needed. Chlorine is a common and effective disinfectant but are also known to

react with organic material and form disinfection by products (DBP) which decreases

the disinfection level and could be a health problem. The goal of this essay is to

evaluate the technology that was installed in October 2009. Investigations of laboratory

data, comparing data before and after with a one way anova test, do not show a

significant improvement of heterotrophic bacteria and free chlorine but TOC, DBP and

total chlorine have improved significantly. The conclusion is that UV-light and coal

filter effectively decreased levels of DBP and TOC in the pool water of Hogdalen. High

levels of heterotrophic bacteria before October 2009 was a result of free chlorine

forming chlorinated byproducts with organic material which led to low levels of free

chlorine. After October 2009 the level of free chlorine was not high enough to disinfect

the water properly because of adjustment problems to new technology. Total chlorine

levels have decreased after October 2009 which makes it possible to add more chlorine.

Although heterotrophic bacteria did not decrease as expected the improvement of DBP

levels decreases health risks for both swimmers and employees staying in the pool area.