U and Th in some brown coals of Serbia and Montenegro and their environmental impact

Abstract

Goal, Scope and Background. The objective of this paper is to determine and compare the concentrations of U and Th in soft to hard brown (lignite to sub-bituminous) coals of Serbia and Montenegro. It also presents comparison of the obtained data on U and Th concentrations with the published data on coals located in some other countries of the world. Almost the whole coal production of Serbia and Montenegro is used as feed coals for combustion in thermal power plants. Methods.Channel samples from open pit and underground mines and core samples were collected for hard and soft brown coals. For the analysis the samples were decomposed using microwave technique. Obtained solutions containing U and Th were analyzed by inductively coupled plasma mass spectroscopy (ICP-MS) using NIST standards. Results. Concentration of U from the investigated basins and the corresponding mine fields ranges within 0.60-70.10 mg/kg, 0.65-3.20 mg/kg, 0.95-6.59 mg/kg, 1.20-6.05 mg/kg, 0.80-6.66 mg/kg, 0.18-89.90 mg/kg, 0.19-4.14 mg/kg, and 0.28-3.52 mg/kg for the Kostolac, Kolubara, Krepoljin, Sjenica, Soko Banja, Bogovina East field, Senje-Resavica and Pljevlja basins, respectively. Concentration of Th ranges within 0.20-2.60 mg/kg, 0.84-6.57 mg/kg, 1.48-6.48 mg/kg, 0.12-2.71 mg/kg, 0.13-4.95 mg/kg, 0.14-3.48 mg/kg, 0.29-3.56 mg/kg, and 0.17-1.89 mg/kg for the

Use of honeybees (Apis mellifera L.) as bioindicators of spatial variations and origin determination of metal pollution in Serbia

“…At different places it was already concluded that emissions Al and Cr are coming from the fly ash of these power plants. 27,40,44,32 This is also confirmed by their separate cluster in CA (Fig. 1).…”

“…This coal has relatively high concentrations of Mn, which is much higher than Clarke values for brown coals, and this explains the higher Mn content in honeybees sampled at locations near thermal power plants "Kostolac A & B". 44 Ni had statistically higher concentrations at the MS sampling site compared to PV, KO, PABA, PAZV, BGVT and DR sampling sites. Statistically lower concentrations were found at PV in relation to STK, BGPO, DR, BGVT, PAZV and PABA (Table II, Fig.…”

“…Coal combustion can have a negative effect on Co concentrations in the environment due to its presence in the fly ash produced. 43 Therefore, KO and STK sampling locations are positioned in the vicinity of the thermal power plants "Kostolac", and Životić et al 44 have concluded that coal from this basin has relatively high content of Co, therefore this can explain the higher concentrations of this element at these sites. Co is also present in higher concentration in urban environments due to intense traffic.…”

Cancer risk assessment after exposure from natural radionuclides in soil using Monte Carlo techniques

“…A lot of publications dealt with determinations of activity concentrations of natural radionuclides in soil (Spasić Jokić et al 1998;Radosevic et al 2002;Spasić Jokić et al 2002;Bikit et al 2005;Dragović and Onija 2006;Životić D et al 2008), but risk assessment using epidemiological research or with Monte Carlo modeling was never performed.…”

Evaluation of two radiochemical procedures for the determination of uranium and thorium isotopes in coal samples

“…The literature describes methods based on acid leaching the sample to determine its uranium and thorium activity concentrations by alpha-particle spectrometry [12]. The microwave digestion technique is suitable for determination of trace elements in coals by mass spectrometry [11,13], although the use of HF can cause problems with this technique [14].…”