The objective of this research was to evaluate the treatment efficiency of a trichloroethylene (TCE) contaminated soil by combined technologies of the suspension of palladized nanoiron and electrokinetic remediation process. First, nanoiron and palladized nanoiron were prepared using the chemical reduction method. Then they were characterized by various methods. Micrographs of scanning electron microscopy have shown that a majority of these nanoparticles were in the range of 50-80 nm. Specific surface areas were determined to be 76.88 m2/g and 100.61 m2/g for the former and latter, respectively. Results of X-ray diffractometry have shown that both types of nanoiron were poor in crystallinity. Three anionic dispersants were employed for evaluating their performance in stabilizing various nanoiron. Results have demonstrated that an addition of 1 wt% of Dispersant E during nanoiron preparation would result in a good stabilization of nanoiron. If the system pH was adjusted to 2.99, nanoparticles would settle rapidly. Batch tests were carried out to investigate the effects of various operating parameters on degradation of TCE in aqueous solutions. Experimental results have indicated that palladized nanoiron outperformed nanoiron in treatment of TCE in this study. The employment of Dispersant E would enhance the treatment efficiency further. Test results also showed that a linear increase of reaction rate constant was found with an increasing dose of palladium from 0.05 wt% to 1 wt% based on the mass of nanoiron. Further, an exponential increase of reaction rate constant would be obtained with an increasing pH. As for mixing intensity, it was found to be insignificant to the treatment efficiency of TCE in aqueous solutions. The final stage of this study was to evaluate the treatment efficiency of combined technologies of the suspension of palladized nanoiron and electrokinetic remediation process in treating a TCE-contaminated soil. Test conditions used were given as follows: (1) initial TCE concentration: 160-181 mg/kg; (2) electric potential gradient: 1 V/cm; (3) daily addition of 20 mL of suspension of palladized nanoiron (2.5 g/L) to the electrode reservoir; and (4) reaction time: 6 days. Test results have shown that addition of palladized iron suspension to the cathode reservoir yielded the lowest residual TCE concentration in soil. Namely, about 92.5% removal of TCE from soil. On the other hand, addition of palladized iron suspension to the anode reservoir would enhance the degradation of TCE therein. Based on the above findings, the treatment method employed in this work was proven to be a novel and efficient one in treating TCE-contaminated soil.

The objective of this research was to evaluate the treatment efficiency of a nitrate-contaminated soil by combined technologies of the injection of palladized nanoiron slurry and electrokinetic remediation process. First, nanoiron was prepared by two synthesis processes based on the same chemical reduction principle yielding products of NZVI-A and NZVI-B, respectively. Then they were characterized by various methods. Micrographs of scanning electron microscopy have shown that a majority of these nanoparticles were in the range of 50-80 nm and 30-40 nm, respectively. Results of nitrogen gas adsorption-desorption show that NZVI-A and NZVI-B are mesorporous (ca. 30-40 Å) with BET surface areas of 128 m2/g and 77 m2/g, respectively. Results of X-ray diffractometry have shown that both types of nanoiron were poor in crystallinity. Results of zeta-potential measurements indicated that NZVI-A and NZVI-B had the same isoelectric point at pH 6.0. Although NZVI-A and NZVI-B were found to be superparamagnetic, their magnetization values were low. Poly acrylic acid (PAA), an anionic dispersant, was employed for stabilizing various types of nanoiron. Then Palladium¡]ca. 1 wt% of iron¡^ was selected as catalysis to form palladized nanoiron¡]Pd/Fe¡^. Results have demonstrated that an addition of 1 vol. % of PAA during the nanoiron preparation process would result in a good stabilization of nanoiron and nanoscale Pd/Fe slurry. Batch tests were carried out to investigate the effects of pH variation on degradation of nitrate aqueous solutions. Experimental results have indicated that palladized nanoiron outperformed nanoiron in treatment of nitrate in this study. Apparently, an employment of catalyst would enhance the treatment efficiency. Further, an exponential increase of the reaction rate was found for the systems at low pH. The final stage of this study was to evaluate the treatment efficiency of combined technologies of the injection of palladized nanoiron¡]Pd/Fe¡^ slurry and electrokinetic remediation process in treating a nitrate-contaminated soil. Test conditions used were given as follows: (1) slurry injection to four different positions in the soil matrix; (2) electric potential gradient: 1 V/cm; (3) daily addition of 20 mL of palladized nanoiron (4 g/L) slurry to the injection position; and (4) reaction time: 6 days. Test results have shown that addition of palladized nanoiron slurry to the anode reservoir yielded the lowest residual nitrate concentration in soil. Namely, about 99.5% removal of nitrate from soil. On the other hand, the acidic condition of soil matrix around the anode reservoir would enhance the degradation of nitrate therein. Based on the above findings, the treatment method employed in this work was proven to be a novel and efficient one in treating nitrate contaminated soil.

Abstract The object of this study was to investigate the synthesis of a nanoscale zero-valent iron slurry (NZVIS) for use in Fenton-like reactions, and to evaluate its efficiency for As(III) oxidation to As(V) in spiked deionized water and simulated groundwater containing humic acid. Furthermore, this study used injection of the nanoiron slurry combined with electrokinetic processes to remediate As(III) in soil. NZVI was prepared by a chemical reduction process. The efficiency of using 3 wt% soluble starch (SS) to stabilize NZVI was also studied. It was found that the SS could keep the nanoparticles dispersed for over one day. The NZVI was characterized by XRD, FE-SEM, ESEM-EDS, and EDS-mapping, to observe its morphology and crystal structure. In this research the iron species observed took non-crystalline forms. In water batch tests, studies in deionized water were compared with those in simulated groundwater with humic acid, and dissolved oxygen content was adjusted. Injection of NZVIS oxidized As(III) to As(V) in all cases. In both deionized water and simulated groundwater, it was found that when the dissolved oxygen(DO) content was not increased, the NZVIS generated non-selective oxidant OH¡E, thus reducing the As(V) production rate. When dissolved oxygen content was increased, the DO oxidized organic matter present in the simulated groundwater, allowing the OH¡E to react further with As(III) and increasing the As(V) production rate. Finally, a test was performed in actual groundwater under optimal reaction conditions, without increasing the dissolved oxygen content, for comparison of As(V) yield. The concentration of As(V) was found to be higher in this test (As(V) Conc. = 17.55 £gg/L) than when using simulated groundwater (As(V) Conc. = 4.63 £gg/L). This study further examined NZVIS injection combined with electrokinetic (EK) technology for the remediation of soil columns containing a low concentration (initial conc. = 100 mg/kg) and a high concentration (initial conc. = 500 mg/kg) of As(III). EK alone without injection of NZVIS (Test E-1) resulted in a residual soil As(V) concentration of 24 mg/kg in the low-concentration test group. In Test E-2, where NZVIS was injected into the anode reservoir, and Test E-3, where NZVIS was injected into the cathode reservoir, residual soil As(V) concentrations were 2.3 mg/kg and 3.4 mg/kg, respectively. The high-concentration test group was comprised of Test E-4 (EK alone without injection of NZVIS), Test E-5 (NZVIS injected into anode reservoir), and Test E-6 (NZVIS injected into cathode reservoir). In these tests, only soil sections 0.2 and 0.4 (normalized distance from anode reservoir) met soil regulation standards. Residual As(V) concentrations in soil sections 0.6, 0.8, and 1.0 are much higher than the regulatory standard. In soil section 1.0, the residual As(V) concentration was less in Test E-6 than in Test E-5 (116.6 mg/kg and 183.5 mg/kg, respectively). This may be because at high pH values, the iron surface does not corrode, instead arsenic adsorption prevails. Only a fraction of negatively charged As(V) species will migrate towards the anode resulting in a relatively low soil As(V) concentration near the cathode.

This master's thesis is focused on remediation of groundwater polluted by chlorinated ethenes with a use of nanoiron particles. Three injections of different types of nanoiron were carried out in the contaminated area of Spolchemie a.s. company in Ústí nad Labem. The main aim of the thesis was to compare effectiveness of those three applications. The remediation of groundwater was done by direct- push injection of suspension of nanoscale zero-valent iron. After that a monitoring of groundwater level and physicochemical parameters was performed. Samples of groundwater were collected during the monitoring and were analysed for contaminants and products of dechlorination. It was discovered that NANOFER STAR nanoiron had the strongest influence on reductive dechlorination. This was reflected by concentration decrease of TCE by 84 %, VC by 60 % and total concentration of CHC by 39 % in the period three months after the injection and the increase of degradation products of chlorinated ethenes. Injections of conservative tracers potassium bromide and lithium chloride served as a criterion for differentiation between the process of dechlorination and simple dilution effect. The effectiveness of NZVI-C3 nanoiron and NANOFER STAR with CMC nanoiron were notably lower than the bare NANOFER STAR nanoiron. In...

This diploma thesis deals with the effectiveness of separation technologies for water treatment. The first theoretical part mentions types of pollution that can be found in surface water. Furthermore, the interparticle interactions affecting the stability of colloidal dispersions are discussed. The following is a description of the principle, procedure, mechanisms of coagulation and factors influencing this process. The chapter dealing with types of water treatment is followed by a more detailed description of the individual separation technologies used in the water treatment plants. The important passage in the theoretical part is the description of materials and reagents used in laboratory experiments. The coagulants nanoiron and sodium water glass are characterized, as well as Bayoxide E33, CFH 0818, FILTRASORB 100 activated charcoal and DORSILIT silicate sand. The experimental part of the thesis analyses the jar test procedure. The flocculation tester intended for the jar test was used for laboratory coagulation using nanoiron and sodium water glass. The effectiveness of selected coagulants in the removal of turbidity from water during sedimentation of flakes produced in reaction vessels was investigated. In addition, the effectiveness of individual filtering materials in the removal of turbidity from water containing nanoiron/sodium water glass was investigated. In the end, the results of laboratory tests are compared and evaluated, including photos taken during experiments.

This master´s thesis deals with the possibilities of innovation process water treatment. Specifically, to explore the use of sodium water glass and nanoiron in removing heavy metals from raw water at the drinking water treatment. For the comparison was used traditionally used coagulant, particularly liquid aluminum sulfate. The introductory part deals with the possibility of modifying the surface water during the treatment process such water into potable water. This chapter is a description of the quality of raw water used, then the description of currently used separation processes. Furthermore, they are described and commonly used types of treatment plants. Conclusion The introductory section deals with traditional coagulants and form a suspension. Another part of this master´s thesis has been devoted to the possibilities of innovation in the treatment of raw waters as drinking water, describes the options and features of the use of water glass and nanoiron. The following section describes the experimental part of this thesis. It is followed by the experimental results. The last chapter summarizes the acquired knowledge and commented on the measured values of the experimental part. This work also shows several specific projects using innovative technologies presented.