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Notes:
Volume 2
Journal of Environmental Research
Page 53
JOINT EVENT
July 26-27, 2018 Rome, Italy
&
6
th
Edition of International Conference on
Water Pollution & Sewage Management
4
th
International Conference on
Pollution Control & Sustainable Environment
Mobile toilets chemicals: Its influence on activated sludge microorganisms
Vitezova M
1
, Kopecka M
1
, Vitez T
2
and
Dokulilova T
2
1
Masaryk University, Czech Republic
2
Mendel University, Brno, Czech Republic
O
ur work focuses on the wastewater treatment process, especially on the activated sludge. The activated sludge is composed
of varied groups of microorganisms which play the crucial role in the removal of the organic matter and nitrogenous
substances from the wastewater. In the previous study we found out that the chemical substances used regularly as toilet
chemistry negatively influence respirometric activity of the activated sludge. Regarding this fact, we decided to isolate different
bacterial strains from the activated sludge to study the influence of the chemical substances on bacterial growth characteristics
and mainly on the length of the lag phase. Lag phase is defined as the period where the individual bacteria are maturing and not
yet able to divide. They adapt themselves to the new growth conditions. We isolated three bacterial strains from the activated
sludge obtained from the municipal wastewater treatment plant in Modřice, Czech Republic (513.000 PE). The bacterial strains
were cultivated on nitrate broth medium and on the basis of morphological features and Sanger´s sequencing of the DNA we
have determined them as
Paracoccus aminophilus, Ralstonia pickettii
and
Psychrobacter
sp. The growth of these bacterial strains
was measured by the microplate reader Tecan Sunrise
TM
(Tecan Trading AG, Switzerland). The samples examined contained
inoculum of the strains mentioned above (
P. aminophilus, R. pickettii
and
Psychrobacter
sp.) and the pure chemical substances
in the appropriate concentrations. The results were evaluated by equations of bacterial growth. The length of the lag phase
differs depending on the nature of the chemical substances. Bronopol, a substance frequently used in mobile toilets, prolongs
the lag phase very significantly. On the other hand, limonene or citric acid shortens the time of bacterial adaptation. The
retention time of wastewater in the activation tank lies usually in the range of 6 to 8 hours. Regarding the extended lag phase
the bacterial metabolism is insufficient for the properly treated wastewater.
Biography
Vitezova M graduated her PhD studies in Microbiology in 2000 and was habilitated in 2014. She works as Head of Section of Microbiology at Masaryk University
in Brno. She established the Laboratory of Anaerobic Microorganisms. She focuses on the study of methanogenic archaea and sulfate reducing bacteria in the
environment, wastewater treatment process and biogas production process.
vitezova@sci.muni.czVitezova M et al., J Environ Res 2018, Volume: 2