Turbidity and suspended solids can provide protection of microorganisms against disinfectants and environmental stress. This study suggests hardness plays a role although the experimental conditions were limited.
[Effects of algae and kaolinite particles on the survival of bacteriophage MS2]
He Q, Wu QQ, Ma HF, Zhou ZM, Yuan BL. [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui “Huan jing ke xue” bian ji wei yuan hui.].” Huan Jing Ke Xue. 2014 Aug;35(8):3192-7. Article in Chinese.
In this study, Bacteriophage MS2, Kaolinite and Microcystis aeruginosa were selected as model materials for human enteric viruses, inorganic and organic particles, respectively. The influence of the inorganic (Kaolinite) or organic (Microcystis aeruginosa) particles on the survival of MS2 at different conditions, such as particles concentration, pH, ion concentration and natural organic matter (NOM) were studied. The results showed that Kaolinite had no effect on the survival of phage MS2 except that apparent survival of MS2 increased 1 logarithm in higher hardness water. Microcystis aeruginosa addition reduced 1 logarithm of MS2 survival. However, when the pH value was greater than 4.0 or the concentration of Microcystis aeruginosa was less than 1.0 x 10(6) cells x L(-1), Microcystis aeruginosa addition had no influence on the survival of MS2. In higher hardness water, Microcystis aeruginosa protected MS2 viruses and then increased the survival of MS2. In drinking water, resource containing higher concentration of particles, the survival ability of virus would be enhanced with the increase of the hardness and then elevated the risks of drinking water safety.