Postopki nanoremediacije so običajno načrtovani tako, da se upošteva le en kontaminant ali skupina kontaminantov. V obravnavanem delu smo uporabili celovit pristop k raziskavam procesov, ki hkrati potekajo pri čiščenju vode iz male biološke čistilne naprave (MBČN) z različnimi nanodelci nič-valentnega železa (nZVI). Preizkušene so bile tri različice nZVI: nZVI sintetizirani v laboratoriju, komercialni Nanofer STAR in Nanofer25 slurry, ki se razlikujejo po reaktivnosti in po metodah sinteze. Vzorci vode iz iztoka MBČN so bili remediirani z različnimi koncentracijami nZVI, pri različnih časih mešanja in usedanja železovih delcev, z namenom optimizacije učinkovitosti odstranjevanja izbranih potencialno toksičnih elementov (PTE), dušikovih zvrsti in patogenih bakterij (koliformne bakterije, Escherichia coli, intestinalni enterokoki in Clostridium perfringens). Rezultati so pokazali, da so laboratorijsko sintetizirani nZVI najbolj reaktivni med testiran nanodelci. Najbolj učinkovito so odstranjevali PTE in patogene bakterije. Vendar pa je uporaba laboratorijsko sintetiziranih nZVI omejena, saj v vodo sproščajo B, ki izvira iz reagentov, uporabljenih pri njihovi sintezi. V določeni meri so vse preiskovane vrste nZVI znižale koncentracije nitrata in nitrita z pretvorbo v amonijev kation. Dodatna tvorba amonijevega dušika je bila posledica interakcij nZVI z organskim dušikom, prisotnim v vodi iz MBČN. Pri optimalni koncentraciji dodanih nZVI v obliki Nanofer25 slurry, optimalnim trajanjem mešanja in usedanja smo dosegli najučinkovitejšo odstranitev PTE in dezinfekcijo patogenov.
COBISS.SI-ID: 30391847
Immobilization is one of the most effective methods for remediation of contaminated soil. The soil is mixed with the additives, which leads to the formation of an inert composite. For the study of remediation, the most contaminated part of the soil from the area of Old Zinc-works site in Celje was used, which was classified as hazardous waste on the basis of exceeded limit concentrations of water-soluble Zn. We investigated the efficiency of various industrial wastes (paper ash, coal fly ash, ladle slag from steelmaking and red mud from bauxite processing) as additives for immobilization of the soil. Paper ash, coal fly ash and ladle slag have the potential to form hydration products for the chemical immobilization of contaminants. Red mud was not hydraulically active and was partially neutralized. Increase of the effectiveness of immobilization in composites with time is associated with the formation of new minerals in hydration and pozzolanic reactions. Adsorption is the main mechanism of immobilization using red mud. Composites using paper ash, coal fly ash and red mud are environmentally acceptable, considering the inertness limit values, while composites with ladle slag have exceeded the limit for Mo in the aqueous eluate. All composites, except those with ladle slag, are potentially useful as building materials for remediation of contaminated soil in degraded sites in the form of geotechnical embankments or fills.
COBISS.SI-ID: 2385511
Nanoparticles of zero-valent iron (nZVI) enable the removal of pollutants from the waste water. However, for their safe use, it is necessary to determine the potential risk that represent nZVIs remaining suspended in the remediated water. For this purpose, a new SP-ICP-MS method was optimized for the purpose of determining the size and number of nZVI in wastewater. Hydrogen as the reaction gas and the MS / MS detection mode proved to be the most suitable. The optimized method allowed detection of a particle size of 36 nm, without interference. The method was validated by analysing nZVI suspensions in different water matrices using different concentrations of nanoparticles. The results of the investigations of water samples showed that the deposition of nZVI was faster with the use of higher nZVI concentrations and that, with the use of lower concentrations, the particles remain in a more stable suspension. However, it has been demonstrated that the use of nZVI at concentrations of 0.5 g / L or higher does not pose a threat to the environment.
COBISS.SI-ID: 29537063
Zero-valent iron nanoparticles (nZVI) show great potential for the removal of pollutants from wastewater. However, after their use, there is a risk that nZVI remain suspended in the remediated water, which poses a threat to the environment. To investigate this problem, we optimized the new SP-ICP-MS method for the purpose of determining the size and number of nZVI in waste water. H2 was used as a reaction gas in the MS / MS detection mode, which allowed a detection limit of 36 nm particles without interference. The method was used using various iron concentrations (0.1, 0.25, 0.5 and 1 g / L) in various water matrices (Mili-Q, synthetic waste water, water from the effluent from the treatment plant) for the study of behavior nVVI, their interactions with Cd2+ and the efficacy of Cd2+ removal. The agglomeration and sedimentation of nZVI increased with a longer time. Sedimentation was slower in the outflow water than in Mili-Q and synthetic water. Consequently, the removal of Cd2+ was more effective in the outflow water than in synthetic water or Mili-Q. The residue of Cd2+ remaining in water was present in dissolved form or was bound to the remainder of suspended nZVI. The results of examinations of water samples using different nZVI concentrations have shown that the deposition of nZVI is faster with the use of higher concentrations and that when using lower concentrations, the particles remain in a more stable suspension. Nevertheless, the use of nZVI in concentrations of 0.5 g / L or higher does not pose a threat to the environment.
COBISS.SI-ID: 31337255
This study reports on the assessment of the environmental sustainability of different management practices for an environmentally degraded site in Slovenia: the Old Zinc-Works in the town of Celje. Life Cycle Assessments (LCAs) were applied in order to evaluate possible trade-offs by comparing a proposed in situ remediation scenario with two other reclamation scenarios (scenario 2: incineration, metal extraction, underground disposal and reclamation of the site by refilling it with replacement material, and scenario 3: underground disposal and reclamation of the site by refilling it with replacement material) and with a no-action scenario. The results of the comparisons performed show that in the case of the in situ remediation scenario, the consumption of resources is smaller by a factor of 51 compared to that in the second scenario and by a factor of 7 compared to that in the third scenario. The impacts on human health and ecosystem quality are approximately 30 and 3.5 times less in the first scenario than in the second and third scenarios, respectively. Compared to the impact of the no-action scenario, the impact on human health of the in situ soil remediation scenario is approximately 6 times less, whereas its impact on the ecosystem is approximately 4 times less. The results confirmed that the in situ soil remediation scenario is the most sustainable practice from an environmental point of view. Its main advantage lies in the achieved conservation of natural resources....
COBISS.SI-ID: 2359655