Papers Published

1. Bohrerova, Zuzana and Linden, Karl G., Ultraviolet and chlorine disinfection of Mycobacterium in wastewater: Effect of aggregation, Water Environment Research, vol. 78 no. 6 (2006), pp. 565 - 571 [106143006X99795] .
   (last updated on 2007/04/09)

   Abstract:
   Mycobacteria naturally aggregate in water, a characteristic that may serve to protect them against disinfection in wastewater. Secondary effluent was spiked with Mycobacterium terrae (M. terrae), sequentially filtered through 100-, 41-, and 20-μm nylon filters to partition aggregate sizes, confirmed using particle-size analysis and microscopy. Each sample was exposed to doses of UV light (10 to 60 mJ/cm² at 254 nm) and free chlorine (27 to 150 mg-min/L at 4°C). Inactivation of M. terrae in wastewater was initially rapid, with 2.5 log reduction at 14 mJ/cm² and 56 mg-min/L for UV and free chlorine, respectively. However, in effluent and 100-μm filtered wastewater, spiked M. terrae was present to the highest doses evaluated. Interestingly, M. terrae passed through 41- and 20-μm filters were inactivated rapidly, with no survivors after moderate disinfection doses. Inactivation of Mycobacteria in wastewater may be compromised by aggregates larger than 41 microns.

   Keywords:
   Disinfection;Bacteria;Agglomeration;Filtration;Chlorine;Ultraviolet radiation;