scholarly journals Occurrence of 222Rn and 226,228Ra in underground water and 222Rn in soil and their mutual correlations for underground water supplies in southern Greater Poland

Author(s):  
Henryk Bem ◽  
Magdalena Długosz-Lisiecka ◽  
Daria Mazurek-Rudnicka ◽  
Piotr Szajerski

AbstractEuropean Union Council Directive 2013/51/EURATOM recently sets out so-called indicator parameters for: radon, tritium and indicative dose of water intended for human consumption. The aim of this research was to elaborate an effective procedure for determination of radon and radium 226,228Ra isotopes (which are potentially the main contributors to the internal dose from drinking and cooking water) and to find the possible relationships between these radionuclides in underground water reservoirs and 222Rn concentration in the soil gas in their vicinity. The research was performed by applying a non-volatile and water-immiscible scintillation cocktail based on a pure diisopropylnaphthalene (Ultima Gold F: UGF), which allow for efficient radon extraction from 0.5 dm3 of water samples to 20 cm3 of scintillation phase and its direct determination with a detection limit of 5 × 10–3 Bq dm−3. The further preliminary concentration of 3 dm3 of crude water samples by evaporation to 0.5 dm3 samples led to the removal of all unsupported 222Rn activity and allowed the 226Ra determination via equivalent 222Rn detection after one-month samples storage using a low-background Triathler liquid scintillation counter in the α/β separation counting mode. Together with determination of 226Ra isotope in water samples, the simultaneous measurements of 228Ra and 222Rn radionuclides concentrations in water as well as 222Rn activity in the soil gas around the water supply sites were performed. The achieved limit of 226Ra detection was at a very low level of 10–3 Bq dm−3. The measured values of 226Ra concentration in 50 public underground water supply units for the Kalisz district of Poland were relatively low and ranged from below detection limit to 28.5 × 10–3 Bq dm−3 with arithmetic mean and median values of 12.9 and 12.2 × 10–3 Bq dm−3, respectively. Weak correlations were observed between activity concentrations of 226Ra and 222Rn in the crude water samples (R2 = 0.31) and 222Rn in water and its concentration in the nearby soil gas (R2 = 0.48).

2013 ◽  
Vol 749 ◽  
pp. 491-494
Author(s):  
Ai Hui Liang ◽  
Qing Ye Liu ◽  
Gui Qing Wen ◽  
Ting Sheng Li ◽  
Zhi Liang Jiang

In HCl solution, the Se (IV) was reduced to SeH2 by NaBH4, and absorbed by solution of ethanol-AgNO3. The Ag+ was reduced to nanosilver that exhibited surface plasmon resonance absorption (SPR) peaks at 292 nm and 420 nm. Under the selected conditions, the value at 292 nm was linear to the concentration of Se (IV) in the range of 0.08-2.0 μg/mL, a detection limit of 0.04 μg/mL. The proposed method was applied to detect Se (IV) in water samples, with satisfactory results.


2013 ◽  
Vol 726-731 ◽  
pp. 1411-1415 ◽  
Author(s):  
Fei Peng ◽  
Shi Bo Liu ◽  
Hai Yan Xu ◽  
Zhi Qun Li

This paper investigated three chlorophyll-a analysis methods in water sample. The UV-VIS spectrophotometry method followed SL88-2012 standard procedure, the results showed the detection limit of chlorophyll-a was 0.22 μg/L, with the lower detection limit of 1.0 μg/L. The detection range of the vivo chlorophyll-a fluorescence method was 0.1-300μg/L, the ratios of different algae matched that prepared in water samples. The detection limits and quantification limits for HPLC by using UVD and FLD were respectively 0.013 and 0.004 μg/L, 0.040 and 0.013μg/L. FLD was more sensitive than UVD for chlorophyll-a analysis, and the recovery of standard addition was in the range of 90.2% to 103.9% with UVD and FLD. Given the different pretreatment procedures of the sample, equipment conditions, correction and precision, vivo chlorophyll-a fluorescence method was the best on-site monitoring and the emergency monitoring method. Spectrophotometer was suitable for routine laboratory determination of chlorophyll-a, especially for bulk water samples. HPLC method had high precision and sensitivity, so this method applied to the determination of exact requirements, microanalysis and pigment separation.


1966 ◽  
Vol 20 (4) ◽  
pp. 212-213 ◽  
Author(s):  
J. D. Kerber

Nickel in catalytic-cracking feedstocks is determined by atomic-absorption spectrophotometry with no sample preparation other than dilution in p–xylene. A modification of the method of additions permits rapid testing with a detection limit of 0.05 ppm Ni and a precision of 0.05 ppm.


1975 ◽  
Vol 32 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Derek A. J. Murray

This report describes a method for the analysis of tri-aryl phosphate esters used commercially as lubricants. In a fish toxicity study, Imol S-140 (tri-tolyl phosphate) was extracted from fish tissue and water samples, hydrolyzed, and the individual phenols measured by gas chromatography as the trimethylsilyl derivatives. The lower detection limit was about 3 ppm of Imol in wet fish tissue.


2013 ◽  
Vol 631-632 ◽  
pp. 18-21 ◽  
Author(s):  
Zhi Liang Jiang ◽  
Mei Ling Tang ◽  
Qing Ye Liu ◽  
Ai Hui Liang

In the condition of 1.24 mmol/L EDTANa2, 16.7 mmol/L NaCl and 0.17 mmol/L Tris, the substrate chain of double-stranded DNA (dsDNA) could be cracked by Pb2+ to release single-stranded DNA (ssDNA) that adsorb onto AuPd nanoparticle (AuPdNP) and form stable AuPdNP-ssDNA, but the dsDNA can not protect AuPdNP that were aggregated to big AuPdNP aggregations (AuPdNPA) under the action of NaCl. The AuPdNP-ssDNA and AuPdNPA could be separated by centrifugation. With the concentration of Pb2+ increased, the released ssDNA increased, the AuPdNP-ssDNA in centrifugation solution increased and the catalytic effect enhanced on the fluorescence quenching reaction of Rhodamine 6G (Rh6G) and NaH2PO2, which led the fluorescence intensity at 552nm to decrease. The decreased fluorescence intensity (ΔF552nm) was linear to the concentration of Pb2+ in the range of 0.33-8.00 nmol/L, a detection limit of 0.21 nmol/L. The proposed method was applied to detect Pb2+ in water samples, with satisfactory results.


Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 140 ◽  
Author(s):  
Yaqi Lu ◽  
Dan Wu ◽  
Ziyin Li ◽  
Quanjie Lin ◽  
Xiuling Ma ◽  
...  

It very important to be able to efficiently detect hydrazine hydrate in an aqueous medium due to its high toxicity. Here, we have proposed a new idea: to construct a sensor for the rapid determination of hydrazine hydrate based on the nano-CuO derived by controlled pyrolysis of HKUST-1 [Cu3(BTC)2(H2O)3]. The as-prepared CuO at 400 °C possesses a uniform appearance with nano-structure via SEM images, and the nano-CuO-400 has exhibited excellent electrocatalytic activity towards hydrazine oxidation. Amperometric i-t curves shows the peak current as linearly proportional to the hydrazine concentration within 1.98–169.3 μmol L−1 and 232–2096 μmol L−1 with the detection limit of 2.55 × 10−8 mol L−1 and 7.01 × 10−8 mol L−1, respectively. Moreover, the sensor constructed in the experiment shows good selectivities, and it is feasible to determining actual water samples.


2013 ◽  
Vol 406 (4) ◽  
pp. 1039-1048 ◽  
Author(s):  
Thanh-Thuy Nguyen-Boisse ◽  
Joëlle Saulnier ◽  
Nicole Jaffrezic-Renault ◽  
Florence Lagarde

Author(s):  
Lebea N. Nthunya ◽  
Sebabatso Maifadi ◽  
Bhekie B. Mamba ◽  
Arne R. Verliefde ◽  
Sabelo D. Mhlanga

The problem of limited water supply in the Vhembe District (Limpopo Province, South Africa) is exacerbated by a preponderance of dissolved salts, which cause disagreeable taste and odour in the water as reported by the communities using this water for drinking. The water treatment plant that supplies the treated water to the communities in the District sources this raw water from the Nandoni Dam at the Livhuvu river catchment. However, there are no scientific studies that have been reported in the literature which focused on determining the levels of water salinity from various water sources in the municipalities of the District. Water samples from various sites across the Nandoni Dam, a primary source of domestic water supply in the region, were collected during all the seasons basis over a period of twelve months in order to ascertain the concentrations of dissolved salts in the dam. Onsite analyses of the water samples were conducted using the YSI ProDSS multimeter, while the laboratory water analyses were conducted using the spectroquant and atomic absorption spectrometers. Although salinity tests seem to indicate that the water sampled across most of the Nandoni Dam is brackish during all seasons of the year with the highest being 750 mg/L, water samples from the dam mid-outlet and the treatment plant are slightly below the WHO brackish water bracket of 500 mg/L with unfavourable taste for drinking. Results from this study indicate that the water sourced from the Nandoni Dam is not suitable for human consumption and therefore requires integrated water resource management, as well as robust and cost-effective water desalination treatment.


2020 ◽  
Vol 55 (6) ◽  
pp. 558-565
Author(s):  
João P. F. Tiago ◽  
Lázaro C. Sicupira ◽  
Rodrigo E. Barros ◽  
Gevany P. de Pinho ◽  
Flaviano O. Silvério

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