Investigation of 137Cs and plutonium isotope sorption–desorption in bio- and synthetic materials

2016 ◽  
Vol 56 (2) ◽  
Author(s):  
Benedikta Lukšienė ◽  
Zita Žukauskaitė ◽  
Nikolaj Tarasiuk ◽  
Evaldas Maceika ◽  
Vitold Filistovič ◽  
...  

Investigations on the pre-concentration of radionuclides (137Cs and plutonium isotopes) from fresh water on solid matrices are presented in this study. A particular focus was given to an innovative physico-chemical removal process such as adsorption of radionuclides from an aqueous medium on new type adsorbents, environmental-friendly materials. Sorption of the tested radionuclides from the lake water solution by environmental assays and synthetic sorbents was compared. Lake water was analyzed for main anions, micro- and macroelements, using ion and atomic absorption chromatography methods, respectively. Batch type and dynamic flow column laboratory experiments were performed. The sorption–desorption capacity of radionuclides by the tested sorbents was estimated based on the results of α- and γ-spectrometric measurements. According to the removal efficiency results, moss can be considered as the best sorbent for plutonium of the tested environmental-friendly sorbents, whereas the moss sorption capacity exceeded even that of the tested synthetic ones. The highest 137Cs removal efficiency from the lake water solution was obtained for granular activated carbon. Application of the dynamic flow method carried out in situ confirmed the reversibility of sorbed background 137Cs activity in the moss observed during the batch type experiments, and the method of the moss bed column turned to be unfit for the pre-concentration of 137Cs from the lake water. Application of a single moss bed column for the 137Cs and plutonium isotope pre-concentration for the first time carried out in situ allowed us to determine the activity concentration of 239,240Pu and 238Pu in the lake water – 4.87±0.98 and 0.67±0.21 mBq/m3, respectively. The reversible 137Cs and different plutonium sorption in the moss apparently indicates different binding properties of these radionuclides to the moss, therefore further investigations on this issue are foreseen.

2021 ◽  
Vol 9 (4) ◽  
pp. 105452
Author(s):  
Jianhua Zhang ◽  
Hongjiao Pang ◽  
Stephen Gray ◽  
Shaoheng Ma ◽  
Zongli Xie ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1316
Author(s):  
Vanessa Miglio ◽  
Chiara Zaccone ◽  
Chiara Vittoni ◽  
Ilaria Braschi ◽  
Enrico Buscaroli ◽  
...  

This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.


2021 ◽  
pp. 118250
Author(s):  
Hamed Peidayesh ◽  
Abolfazl Heydari ◽  
Katarína Mosnáčková ◽  
Ivan Chodák

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.


2000 ◽  
Vol 42 (7-8) ◽  
pp. 335-343 ◽  
Author(s):  
S. Shiba ◽  
S. Hino ◽  
Y. Hirata ◽  
T. Seno

The operational variables of electrokinetic remediation have not been cleared yet, because this method is relatively new and is an innovative technique in the aquifer remediation. In order to investigate the operational variables of the electrokinetic remediation, a mathematical model has been constructed based on the physico chemical mass transport process of heavy metals in pore water of contaminated aquifer. The transport of the heavy metals is driven not only by the hydraulic flow due to the injection of the purge water but also by the electromigration due to the application of the electric potential gradient. The electric potential between anode and cathode is the important operational variable for the electrokinetic remediation. From the numerical simulations with use of this model it is confirmed that the remediation starts from the up stream anode and gradually the heavy metal is transported to the down stream cathode and drawn out through the purge water.


2011 ◽  
Vol 17 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Nada Babovic ◽  
Dejan Markovic ◽  
Vojkan Dimitrijevic ◽  
Dragan Markovic

This paper shows the results obtained in field analysis performed at the Tamis River, starting from the settlement Jasa Tomic - border between Serbia and Romania to Pancevo - confluence of Tamis into the Danube. The Tamis is a 359 km long river rising in the southern Carpathian Mountains. It flows through the Banat region and flows into the Danube near Pancevo. During the years the water quality of the river has severely deteriorated and badly affected the environment and the river ecosystem. In situ measurements enabled determination of physico-chemical parameters of water quality of the Tamis River on every 400 m of the watercourse, such as: water temperature, pH value, electrical conductivity, contents of dissolved oxygen and oxygen saturation. The main reason of higher pollution of Tamis is seen in connection to DTD hydro system. Sampling was performed at 7 points with regard to color, turbidity, total hardness, alkalinity, concentration of ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, iron, chlorides and sulphates in samples. The aim of the present work was to evaluate water quality in the Tamis River taking into account significant pollution, which originates from settlements, industry and agriculture, and to suggest appropriate preventive measures to further pollution decreasing of the river's water.


2012 ◽  
Vol 37 (22) ◽  
pp. 17002-17008 ◽  
Author(s):  
Agileo Hernández-Gordillo ◽  
Francisco Tzompantzi ◽  
Ricardo Gómez
Keyword(s):  

Author(s):  
Mahendra Kumar Awasthi ◽  
Sanjay Kumar Singh

Efficient hydrogen production from aqueous formaldehyde with appreciably high TOF and TON achieved over an in situ generated ruthenium catalyst in water at 95 °C.


2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     


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