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The fate of selected heavy metals in a constructed wetland
KREJSA, Jiří
This study is aimed at removal of cadmium and mercury from municipal wastewater using a constructed wetland with a horizontal subsurface flow. Samples of wastewater, sediments, aboveground and belowground biomass of common reed (Phragmites australis) were analyzed. Average concentrations of cadmium and mercury in inflow water were 0,10 ?g/l and 0,16 ?g/l and in outflow water 0,03 ?g/l and 0,06 ?g/l. Average efficiencies of cadmium and mercury removal were 64,2 % and 63,7 %, respectively. Concentrations of cadmium varied in range 0,008-0,016 mg/kg for aboveground biomass and 0,042-0,081 mg/kg for belowground biomass of common reed. Average concentrations of mercury were 0,010 mg/kg and 0,008 mg/kg for aboveground and belowground biomass, respectively. Average concentrations of cadmium and mercury in sediments were 0,15 mg/kg and 0,15 mg/kg at the distance of 1 m from inflow zone and 0,03 mg/kg and 0,10 mg/kg at the distance of 10 m from inflow zone. Results showed that both cadmium and mercury were predominantly removed from wastewater at the beginning of the wetland bed.
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Removal of lead from wastewater using a constructed wetland
JAHODOVÁ, Jana
Removal of lead from municipal wastewater using a constructed wetland with a horizontal subsurface flow was studied. Wastewater, wetland plant and sediment samples were analyzed using an AAS Thermo Scientific iCE 3500. Average concentrations of lead in inflow and outflow water in 2015 were 1.47 and 0.74 ?g/l, respectively. Average concentrations of lead in inflow and outflow water in 2016 were 0.75 and 0.38 ?g/l. The average efficiency of lead removal was 49.2 %. Lead concentrations in vegetation (Phragmites australis) varied in the range of 0.081-0.087 mg/kg and 0.48-0.17 mg/kg for the above and belowground biomass, respectively. Lead concentration in sediments were 9.79 and 4.86 mg/kg at distances of 1 and 10 m from inflow zone. Lead and other heavy metals were predominantly removed from wastewater at the initial part of the wetland bed.
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Concentration of cobalt in wastewater and its removal using a constructed wetland
PIVONKOVÁ, Eliška
The presented bachelor's thesis discusses monitoring of wastewater in a vegetation wastewater treatment plant in the village Slavošovice, Czech Republic and an efficiency of cobalt removal from wastewater. Cobalt concentration in wastewater was determined using the atomic absorption spectrometry. The analyzed wastewater samples were taken from different parts of the constructed wetland's system in the period from March to September 2015. The obtained results enabled to calculate the efficiency of cobalt removal from wastewater.
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Concentration of nickel in wastewater and its removal using a constructed wetland
KOUKLÍKOVÁ, Etela
This bachelor thesis is focused on the determination of the efficiency of the nickel removal from wastewater using constructed wetlands. During 2015, wastewater from the vegetation wastewater treatment plant in the villageSlavošovice was analyzed. Nickel concentration in wastewater was determined by atomic absorption spectrometry. Samples of wastewater were taken eight times from six different parts of the wetland. The obtained results of the wastewater analysis I evaluated the degree of the nickel removal in the profile of the vegetation wastewater treatment plant. The analysis was conducted using an atomic absorption spectrometer Thermo Scientific iCE 3500. The characteristics of the analytical method were as follows: accuracy (97.64%), precision (3.53%), sensitivity (9 x 10-3 s.l/g), limit of detection (LOD = 0.161 ?g /l), limit of quantification (LOQ = 0.537 ?g/l), linear dynamic range (0,537 - 10 ?g/l) and correlation coefficient (0.9992). The concentration of nickel obtained from samples from the inflow zone differed by several tenths or units of ?g/l compared to the inflow concentration value. The nickel of concentration at the outflow from the system was decreased by units of ?g/l compared to the inflow. The gradual decrease of the concentration of nickel was observed for the samples taken from the profile of the constructed wetland vegetated bed. The obtained results document the sufficient efficiency of the nickel removal from municipal wastewater in Slavošovice constructed wetland. The outflowing water, guided to a nearby stream, contains lower concentrations of nickel in comparison with the raw wastewater. With respect to aquatic organisms, it is very important to reduce the concentration of nickel in treated wastewater. Actually, the nickel toxicity for aquatic organisms is much higher than for humans.
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The efficiency of the anionactive surfactants degradation in a constructed wetland vegetation bed.
HAVELKA, Michal
This bachelor thesis is focused on the validation of the anionactive surfactants spectrophotometric determination method. Data from the seasonal monitoring of the anionactive surfactants in a constructed wetland for wastewater treatment with a horizontal subsurface flow were used for the anionactive surfactants degradation efficiency determination and for the determination of the relationship of the wastewater inflow, the constructed wetland´s water temperature, and the constructed wetland´s water redox potential to the degradation efficiency. The spectrophotometric method of the anionactive surfactants determination with methylene blue was used during the study.
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Gaseous products of microbial decomposition of organic pollution in constructed wetland used for wastewater treatment.
ŠTĚPÁNEK, Jindřich
This master thesis is dealing with monitoring of gaseous products of microbial decomposition of organic pollution in constructed wetland. This wetland was used for wastewater treatment in a village Slavošovice, Czech Republic. Emissions of CO2, CH4 and N2O were measured in one treatment bed of the system. The emissions were quantified, their seasonal course was followed, and the main factors affecting gaseous emissions were identified. Only 3 % of total C emissions were in form of methane, N2O emissions were negligible and only 1,5 % of nitrogen denitrified were in form of N2O. Carbon and nitrogen balances of the system were estimated.
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