|
|
The use of the Daphnia magna organism in the evaluation of the efficiency of domestic wastewater treatment plants
Petrová, Adela ; Komendová, Renata (oponent) ; Zlámalová Gargošová, Helena (vedoucí práce)
The aim of this bachelor thesis was to assess the efficiency of two domestic wastewater treatment plants (WWTPs) with a capacity of 30–500 equivalent inhabitants (EO), with 10 to 20 inhabitants using them. The evaluation was carried out through ecotoxicological tests on the aquatic organism Daphnia magna, and analytical analysis, where selected indicators specified in Government Regulations No. 401/2015 Coll. and No. 57/2016 Coll. were investigated. In the acute tests, a significant reduction in the toxicity level of the water at the outlet of the treatment plant, compared to the water at the inlet, was observed. In both treatment plants, EC50 values were determined only at the influent, as there was no mortality above 50 % at the effluent. The EC50 values for WWTP 1 were calculated to be 653.9 ml/l (24hEC50) and 471.1 ml/l (48hEC50). For WWTP 2, these values were determined to be 286.4 ml/l (24hEC50) and 186.2 ml/l (48hEC50). Chronic tests also showed that the treated water from the treatment plant at concentrations of 10 % and 1 % did not have a negative effect on the growth and reproduction of D. magna, but promoted the growth of algae used as food. From an analytical point of view, the treatment efficiency in both treatment plants was COD above 70 %, but only WWTP 1 did not exceed the maximum COD value of 220 mg/l for discharge of treated water to surface water. This plant also met the conditions for discharge to groundwater, unlike WWTP 2.
|
host ::
RSS.