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Continuous electrocoagulation of Chlorella vulgaris in a novel channel-flow reactor
Lucáková, Simona
In our laboratory, we employed an electrocoagulation process with iron sacrificial anode leading to the separation of Chlorella vulgaris cells with high efficiency and at the same time acceptable low contamination of separated biomass by iron. Comparing to only centrifugation, the total energy costs of harvesting using electrocoagulation as a pre-concentration step prior to centrifugation were reduced by more than 80%. After extensive study of the influence of relevant process parameters.
Plný tet:  PDF
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Electrocoagulation method for treatment of polluted waters
Krušinová, Zuzana ; Klusoň, Petr (advisor) ; Mašín, Pavel (referee)
Many drinking water treatment facilities face problems with algal organic matter (AOM) due to eutrophication of the environment and frequent occurrence of algal blooms. AOM can cause deterioration of water organoleptic properties, but the main threat is the potential for acting as a precursor of toxic disinfection by-products (DBPs). The presented master thesis deals with the possibility of using electrocoagulation (EC) - an innovative electrochemical method - to remove cellular organic matter (COM) produced by cyanobacteria Microcystis aeruginosa from drinking water. EC is similar to widely used chemical coagulation, the difference is that during EC the coagulant is produced by electrochemical dissolution of an iron or an aluminum electrode. Synthetic water with COM concentration of 5.5 and 8.5 mg/L of TOC was used for the experiments. The target value of conductivity (4.5 mS/cm) was reached by addition of NaCl. pH of the solution was adjusted by HCl and NaOH. During some of the experiments, NaHCO3 was added to increase the ANC4.5. The experiments were conducted in a batch mode with a stainless-steel cathode and an aluminum or an iron anode. The coagulant dosage was regulated by applied electric current passing through the electrodes. Flocs were separated by sedimentation and centrifugation. COM...
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Removal of Toxic Metals from Contaminated Water by Elektrocoagulation Method.
Mašín, P. ; Krystyník, Pavel ; Klusoň, Petr ; Jadrný, J. ; Krušinová, Z. ; Kroužek, J.
This paper is focused on a pilot scale electrocoagulation method for heavy toxic metal removal from contaminated ground water and waste water. High efficiency, over 99 % removal of ions Cr6+ and Ni2+ (after arise pH to value 9) has been achieved, during treatment groundwater with content 40 respectively 90 mg/l of chromium and nickel. Mainly disadvantage this technology was coating of electrode plate with ferrous oxides or hydroxides and decreasing of heavy metal removal. It was necessary performed periodical flushing with water and regeneration electrode plates helpful solution of H3P04. Following application of electrocoagulation was performed in wastewater produced from leaking of fly ash from incineration plant of municipal waste. Electrocoagulation process was very effective for reducing of Zn and Pb, but decrease of content Cd was only 20 %. It was found, that Cd must be coprecipitated with Na2S and other alternatives are not effective. Thus, for this electrocoagulation technology was found appropriate utilization for effectively reduce of Zn content.\n
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019040408010 - PDF
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Pilot Scale Testing of Electrocoagulation to Remove Cr6 +, Ni and Zn from Contaminated Groundwater.
Mašín, P. ; Krystyník, Pavel ; Klusoň, Petr ; Krušinová, Z.
Testing has shown a high efficiency in removal of toxic metals, especially chromium (Cr6+ and Crcelk.). The content of contaminants in treated water was mostly under limits for discharging water into the surface water recipient. The pH 4.5 of inlet water was optimal for the electrochemical reduction of Cr6+ to Cr3+ followed by coagulation. Increase of pH was performed in order to increase efficiency of Ni removal. The power input of electrode cells at the current input of 45 A was 1.3 kWh.m-3 of cleaned water. The life of one electrode pack was 35 m3 of contaminated water at mentioned current input.
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Experimental Report, Period 9-12/2017, Project: Electrocoagulation Unit for Microalgal Biomass Separation.
Brányiková, Irena ; Vojtěchovský, R. ; Čermáková, Lenka
Production of microalgae in the world is increasing every year, but their use in food, cosmetics, feed and biofuel production is still limited by the high production price and high energy input. The substantial part of the energy costs lies in the separation of algal biomass from the medium, which is most often performed on plate centrifuges. The harvest concentration of algal suspensions in most cultivation systems ranges between just 1-5 g/L. Therefore, to obtain 1 kg of dry biomass, it is necessary to remove 200 to 1000 liters of water (by centrifuging and then drying). This amount of water and thus the energy input can be reduced via flocculation added as a pre-step prior to centrifugation. Electrofloculation is type of floculation, where the flocculant is directly formed by dissolving the electrodes. Suitable electrode material and parameter set enable obtaining of biomass, which is not contaminated by chemical flocculants and meets requirements for food stuff. The main objective of this project is to develop a continuous electroflocculation device suitable for these purposes.\n
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Experimental Plan for the Project: Electrocoagulation Unit for Microalgal Biomass Separation.
Brányiková, Irena ; Vojtěchovský, R. ; Čermáková, Lenka
Electrofloculation (electrocoagulation) of microalgae is a highly complex process involving a number of very complex transport, electrochemical, hydrodynamic and surface phenomena. The description of this process at the level of single mechanisms involved is too complicated and experimentally demanding, fortunately it is not absolutely necessary for the practical application. The electrofloculation was therefore approached by an engineering method that identified the criteria (range) of the desired variables and the main factors that affect them. For these factors, partial factorial experimental plans were designed.
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Pilot-scale Operation of Electrocoagulation for Removal of Toxic Metals.
Krystyník, Pavel ; Mašín, P. ; Krušinová, Z. ; Klusoň, Petr
The process was tested in pilot-scale unit placed in movable container and operated in continuous regime. The results have shown that the removal efficacies are strongly dependent on the dose of coagulant, which is the most important and crucial parameters affecting performance of electrocoagulation and of course on other process parameters. It is also very reliant on contaminant content in treated effluent. An addition of flocculating agent was also tested on the improvements of process performance.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22018100509391 - PDF
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The pilot plant scale of the electrochemical elimination of Cr and Ni
Krušinová, Zuzana ; Klusoň, Petr (advisor) ; Žebrák, Radim (referee)
Electrocoagulation is a progressive yet not thoroughly understood method used to purify water contaminated by toxic elements and compounds. This bachelor thesis is focused on pilot scale testing of the electrochemical elimination of chromium and nickel from groundwater, realized on the premises of the company Velobel in Zlaté Hory. Firstly, it was essential to optimize the electrocoagulation process according to the parameters and composition of the groundwater. Secondly, it was necessary to test a continuous long-term operation that would make possible complete decontamination of the site. The electrocoagulation process was followed by addition of flocculant which was used to promote the sedimentation of the sludge. Lime solution was added simultaneously to change pH and to help eliminate nickel. This was followed by sedimentation and the purified water was led away by an overflow. The sludge was treated by a filter-press. Hexavalent chromium content in water samples was analysed spectrophotometrically with diphenylcarbazide, whereas trivalent chromium, nickel, zinc and manganese were analysed in a laboratory using ICP-OES (inductively coupled plasma - optical emission spectrometry). It was discovered that the tested technology is very successful in real conditions, with metal removal efficacies...
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