Browsing by Author "Pavelková, Alena"
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- ItemCOST-EFFECTIVE REMEDIATION USING MICROSCALE ZVI: COMPARISON OF COMMERCIALLY AVAILABLE PRODUCTS(SOC ECOLOGICAL CHEMISTRY & ENGINEERING, OPOLE UNIV, OLESKA 48, OPOLE, 45-951, POLAND, 2020) Pavelková, Alena; Stejskal, Vojtěch; Vološčuková, Ondřejka; Nosek, JaroslavZero-valent iron is very effective in the treatment of groundwater contaminated with chlorinated hydrocarbons and solvents broadly used in industrial production. In terms of its sustainability and cost, a legitimate effort has been devoted to the optimization of the remediation process, which can be demanding and expensive. In this study, the application potential and fundamental properties of several commercial micro-sized zero-valent iron (mu ZVI) were investigated. Although the manufacturers report the basic parameters of mu ZVI, it has been shown that the actual reactivity of apparently similar products varies notably. This work was focused on monitoring of frequently occurring contaminants. The actual contaminated water from the Pisecna locality former landfill of industrial waste, with high levels of chlorinated ethenes and ethanes (PCE, TCE, cis-1,2-DCE and 1,2-DCA) was used for the experiment. The degree of dechlorination reached over 85 % 32 days after the application of mu ZVI in several samples and a far higher reaction rate for smaller particles was observed. Also, the amount of cis-1,2-DCE, which is characterized by slow decomposition, decreased by more than 95 % over the course of the experiment. Smaller particles showed a much longer sedimentation rate and gradual fractionation was also observed. Monitoring of ORP and pH also suggested that the smaller particles possessed a reduction capacity that was sufficiently high even at the end of the experiment. Laboratory tests with apparently similar mu ZVI samples indicated considerable differences in their reaction rate and efficiency.
- ItemLaboratory Comparison of Nzvi / S-nzvi Efficiency in Systems with And Without Power(2019) Vološčuková Ondřejka; Skácelová, Petra; Pavelková, Alena; Slunský, Jan; Nosek, JaroslavThe use of nZVI is well known method for remediation of groundwater contaminated with chlorinated hydrocarbons. The present paper investigates the ability of traditional nZVI and S-nZVI modified with sulphide ion (HS- ) to reduce CHC in real wastewater sample. In the effort to enhance longevity and efficiency of the treatment, experiments were performed under applied voltage (patent 304152, owner MEGA a.s., TUL). Results showed elevated reactivity of nZVI in reactors with passing voltage. The decomposition of the CHC in DC supported reactors occurred several times faster than in reactors without added voltage. However, the analysis of products suggests different pathway of decomposition when S-nZVI is used. The main product of reductive dechlorination was acetylene as opposite to regular nZVI which produced predominantly ethene and ethane. The nZVI provided with DC showed the most rapid decline of all contaminants in the time frame of 5 days.