Distribution of uranium at Mumbai Harbour Bay (MHB)

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay. In addition, the Bay is also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. The average value of uranium concentration reported for Indian Bay water at Tarapur and Mumbai is ~3.0 ppb which is comparable with the reported value for Arabian sea. As such the global average is reported to be ~3.3 ppb by Oceanologists. The present study deals with the distribution of uranium in seawater of MHB. The uranium activity in MHB by alpha spectrometry was found to be between 1.0 and 4.4 ppb with an average concentration of 2.5 ppb which is comparable with the earlier reported average activity of 2.6 ppb in the MHB as well as those reported globally. To compare the results obtained by alpha spectrometry, uranium estimation was also carried out using Laser fluorimeter and the levels of uranium concentration have ranged between 0.8 and 4.9 ppb with an average concentration of 2.7 ppb.     

Determination of rare-earth elements in Periyar River water (Kerala, India) and seawater (Mumbai, India) using neutron activation analysis

During the present work rare earth elements (REEs) in Periyar River water and in seawater from the region of Mumbai, India, have been measured via neutron activation analysis. To separate and concentrate REEs a pre-irradiation separation approach via ion exchange was adopted. Standard addition and radiotracer studies were carried out to validate the analytical methodology including the recoveries of the separations. The measured REE concentrations in the water samples are presented and discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Studies on natural and anthropogenic radionuclides in sediment and biota of Mumbai Harbour Bay

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay and its also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. Sediment samples were collected from various locations of MHB to determine the concentrations of naturally occurring radionuclides like ²²⁶Ra, ²²⁸Ra and ⁴⁰K which varied between 4.0 and 26.0, 5.5 and 19.9, 249.6 and 557.6 Bq kg _(dry) ^?1 respectively and are comparable to the worldwide average concentration. The mean value ratio of ²²⁸Ra/²²⁶Ra in sediment was found to be 1.4, indicating a relatively higher mobility of ²³⁸U compared to ²³²Th. The concentration of anthropogenic radionuclide ¹³⁷Cs in sediment and biota ranged between 3.6 and 54.5 Bq kg _(dry) ^?1 , <0.08 and 0.5 Bq kg _(wet) ^?1 respectively. The ingestion dose to ‘General Public’ due to ¹³⁷Cs intake is 0.02 μSv years^?1 which is negligible compared to the internationally accepted limit of 1,000 μSv years^?1 to ‘members of public’.     

Study on the spatial distribution of 137Cs content in bottom sediment and benthic species of Mumbai off coast

The observed ¹³⁷Cs content in bottom sediment and benthic species of Mumbai off coast varied between 2–370  \( {\text{Bq kg}}_{{ ( {\text{dry)}}}}^{ - 1} \) and <0.08–0.4  \( {\text{Bq kg}}_{{ ( {\text{wet)}}}}^{ - 1} \) respectively. The annual estimated ingestion dose to ‘general public’ due to consumption of benthic species is 0.02 µSv y^?1, which is infinitesimally smaller, in comparison to average annual human exposure of 3.01 mSv and also to the internationally accepted public dose limit of 1,000 µSv y^?1.     

Determination of chronological heavy metal deposition and pollution intensity in the bottom sediments of Mumbai Harbour Bay, India using 137Cs as tracer

Downcore variation of trace metals in sediment cores along the coastal line is one of the markers to assess the intrusion of industrial pollutants into the aquatic environment. Fifty sediment core samples from the Mumbai Harbour Bay (MHB), were studied for the trace element content. MHB is a recipient of effluents from different industries situated all along its coast around Thane–Belapur region. The average concentrations of Titanium (Ti), Manganese (Mn), Iron (Fe), Nickel (Ni), Copper (Cu), Zinc (Zn) were determined by inductively coupled plasma-optical emission spectroscopy and complemented by analysing with energy dispersive X-ray fluorescence spectrometry. In addition to this, depth profiles of K and Ca were also studied to assess the homogeneity of the geological strata of the region. Trace metals such as Cu, Ni and Zn show enrichment between 16 to 28 cm, whereas, uniform distribution through out the core was observed for K, Ca, Ti, Mn and Fe. Chronology of the heavy metal deposition was predicated based on the average sedimentation rate (0.92 ± 0.08 cm year⁻¹) derived using depth-wise ¹³⁷Cs concentration profile in core of bottom sediment. The results of the analysis showed that MHB had received excess inputs of Cu, Ni and Zn in the year 1981, 1988 and 1982, respectively. Surface concentration of Cu, Ni, Zn and Fe compared to the reference site indicates moderate pollution in the recent years whereas for elements K, Ca, Ti and Mn, the values are normal indicating MHB unpolluted for the latter elements.     

Modeling of 137Cs migration in cores of marine sediments of Mumbai Harbor Bay

The vertical concentration profile of ¹³⁷Cs in cores of marine sediment of Mumbai Harbor Bay has been studied by the compartment and the diffusion-convection models. Based on the measured concentrations of ¹³⁷Cs in the sediment layers, the various transport parameters such as sedimentation rate, residence half- time, effective migration velocity, diffusion coefficient and the convective velocities were determined. The sedimentation rate was determined to be 1.61, 1.03 0.69 and 1.25 cm year^?1 from the slope of lines obtained from the depth profile of ¹³⁷Cs in cores using a least-square fitting method at site 1, 2, 3 and 4 respectively. The mean residence half-times, ranging from 11 to 35 years were observed to be the highest at the upper layers (up to 8 cm) of all sites and decreased with sediment depth. Subsequently, the ranges of mean value of effective vertical migration velocity in the same layers were between 0.15 and 0.46 cm year^?1. As expected, the vertical migration in the upper sediment layers was very slow and thereafter increased slowly in the succeeding layers (12 cm onwards) of all sites with a mean ranging from 1.11 to 4.13 cm year^?1. The obtained migration velocities were quite higher than those reported in literatures for global fallout. The convective velocity and diffusion coefficient at each site were assumed to be constant in the whole depth and calculated under the assumption of steady state. Using a depth-zoned bioturbational mixing model, the estimated biological diffusion coefficients ranged from 7 × 10^?7 to 3.8 × 10^?6 cm² s^?1 which were within the literature values reported for shallow coastal environments and deep sea.     

Assessment of elemental contamination in road dust using EDXRF

Road dust samples were collected in different locations of heavy traffic, medium traffic, express way and industrial areas of Mumbai. The concentrations of various elements (Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb) in road dust samples were analyzed using EDXRF. The average elemental profile of road dust in Mumbai was comparable with studies carried out in other countries with slight variations. The estimated geo accumulation indices and enrichment factors indicated moderate elemental contamination and enrichment of anthropogenic elements in road dust samples. Factor analysis of elemental data resolved four sources namely crustal, tyre wear, vehicular/industrial emissions and break wear.     

Natural and fallout radioactivity measurement in Indian soils

The paper presents the results of high resolution gamma-spectrometric measurements of ¹³⁷Cs, ⁴⁰K, ²³²Th and ²³⁸U in Indian soils collected from 24 different places from normal natural radiation background areas. The depth profile of ¹³⁷Cs was studied at sampling sites. The paper also presents ¹³⁷Cs levels in top soil at Mumbai during 1986 to 2000. The results in Mumbai soil indicate clearly the accumulation from fallout only on the top soil and seasonal peaking during the beginning of the monsoon season.     

Large sample neutron activation analysis of dross for gold and silver

Large sample neutron activation analysis of dross from India Government Mint, Mumbai was carried out for quantification of gold (Au) and silver (Ag) using graphite reflector position of Advanced Heavy Water Reactor critical facility at Bhabha Atomic Research Centre, Mumbai. The k ₀-based internal monostandard NAA was used to calculate concentration ratios of Au and Ag with respect to sodium (Na), which was used as an internal monostandard. The concentration ratio values of Au to Na of varying mass of dross showed that mass ≥2 g was the representative sample size for analysis. Concentrations of gold and silver were found to be in the range of 200–400 and 1200–1700 mg kg^?1, respectively in three different samples.     

电化学学术会议年历

中国化学会第30届学术年会 时间：2016-07-01~2016-07-04 地点：辽宁 大连 主办单位：中国化学会 承办单位：大连理工大学 联系人：邓春梅 联系地址：北京市海淀区中关村北一街2号中国化学会 E-mail：cmdeng@iccas.ac.cn 网址：http://www.chemsoc.org.cn/meeting/30th/     

Studies of kidney stones using INAA,EDXRF and XRD techniques

Four kidney stones collected from patients being treated in the Advance Urology Centre of PGIMR, Chandigarh were characterized using instrumental neutron activation analysis (INAA), energy dispersive X-ray fluorescence (EDXRF) and X-ray diffraction (XRD) techniques. For INAA, samples were irradiated in tray rod facility of Dhruva reactor, Mumbai and pneumatic fast transfer system of KAMINI reactor, IGCAR, Kalpakkam. Radioactive assay was carried out using HPGe detector coupled to 8k channel analyzer. Elements determined in the samples by INAA are Zn, Sr, Co, Fe, Cr, Sc, Se, Na and Mn. EDXRF was used for the quantification of Ca. XRD patterns showed that three of the kidney stones are calcium oxalate stone and the other one is uric acid stone. The concentrations of trace elements in general were found to be higher in calcium oxalate stones and positive correlation was observed in the concentrations of Ca with Sr and Zn.     

Production and separation of no-carrier-added <Superscript>208,209,210</Superscript>At produced from heavy ion activation on natural thallium target

No-carrier-added (nca) ^208,209,210At was produced for the first time from ⁹Be induced reaction on thallium carbonate target at BARC-TIFR pelletron, Mumbai, India. The target of 4 mg/cm² thickness was prepared by centrifugation technique. Nca At was separated from the thallium target by liquid–liquid extraction using liquid cation exchanger HDEHP dissolved in cyclohexane and liquor ammonia.     

Foreword of the Fifth Symposium on Nuclear Analytical Chemistry (NAC-V)

The Fifth Symposium on Nuclear Analytical Chemistry (NAC-V) was organized at BARC, Mumbai during January 20–24, 2014 with more than 300 participants. It was sponsored by the Board of Research in Nuclear Sciences, Department of Atomic Energy (DAE), India and organized in cooperation with the IAEA and coorganized by the IANCAS. A total of 240 contributed abstracts along with 27 invited talks and 10 invited short talks were presented in 15 technical sessions. Selected 54 full papers of NAC-V have been accepted after review for publication in special issue of JRNC.     

Trace element study of kidney stones from subjects belonging to stone belt region of India

Kidney stones obtained from six patients belonging to the stone belt region of India (Punjab) were analyzed for inorganic constituents using instrumental neutron activation analysis (INAA) and energy dispersive X-ray fluorescence (EDXRF) techniques. For INAA, samples were irradiated along with IAEA RM Soil 7 as reference standard in CIRUS reactor, BARC, Mumbai. Gamma activity of irradiated samples was measured using a 45% relative efficiency HPGe detector coupled to 8?k channel analyzer. EDXRF method was used for determination of concentration of Ca. The concentrations of ten elements namely Ca, Na, K, Mn, Co, Cr, Zn, Br, Sm and Cl, are reported and discussed.     

Concentration levels and temporal variations of heavy elements in the urban particulate matter of Navi Mumbai, India

Coarse and fine fractions of particulate matter (PM) were collected and analysed for trace elements using Instrumental Neutron Activation Analysis and Energy Dispersive X-ray Fluorescence techniques. The result showed high concentrations of Fe, S, Zn and Pb in both the size fractions. The elemental data obtained is used to analyze the temporal and seasonal variations. The trend showed maximum concentrations of PM and metals during winter and minimum during the monsoon season. Enrichment Factor (EF) and source analysis was performed for the same data set to identify the strength of contribution of anthropogenic sources and the possible contributing sources in the study area. EF studies showed high enrichments of Zn, Pb and As in the fine fraction particles. Crustal, vehicular and industrial emissions are identified as the major contributing sources of PM in the study area.     

Method for determination of radium in seawater using MnO<Subscript>2</Subscript> co-precipitation technique

Radium is considered to be a useful tracer for studying various physical processes of seawater. There are several methods for analysis of radium; however, analysis of radium in seawater by those analytical techniques is a tedious job. Thus a new methodology was optimized for analysis of radium in sea water using MnO₂ co-precipitation followed by gamma spectrometry. The method produced good yield which ranged from 85–98%. The method is simple and requires less amounts of chemicals and no use of acids. Seawater from different western Indian coastal environments viz. Tarapur, Mumbai and Goa were collected and analysed for ²²⁶Ra and ²²⁸Ra using this method.     

Track etch membranes (TEMs) for separation sciences from BARC-TIFR Pelletron accelerator

Track etch membranes (TEMs) program at 14 UD Pelletron accelerator at TIFR, Mumbai, India using 25 micron thick polyethylene terepthalate film is described. Large scale preparation of TEMs by scanning heavy ion beams using a electromagnetic scanner and rolling mechanism using a geared D.C. motor and vacuum rotary feed through are presented. The selection of ions of suitable energy and etching parameters for making various pore sizes were investigated using Rutherford scattered beam from Pelletron accelerator. Pore size and pore density were measured using scanning electron microscope. Scanning width up to 35 cm and irradiation up to 22 m were successfully carried out using this facility. Some applications carried out using these membranes are also mentioned.     

Distribution of uranium in sediment of creek ecosystem

The present study was carried on distribution of uranium isotopes and Thorium in marine sediment from creek of Mumbai Harbour Bay (MHB) using radiochemical separation followed by alpha spectrometry. The activity concentration of uranium and thorium in sediment of MHB has ranged between 1–4 and 1.8–4.5 ppm respectively. The activity ratio of ²³⁴U/²³⁸U in sediment was found close to unity at most of the locations of creek suggesting a conservative behaviour. The observed Th/U ratio (0.9) in comparison to global Th/U ratio (?3.5) in the creek sediment indicates that it receives low radiogenic nature of terronenous input.     

Determination of fluorine concentrations in soil samples using proton induced gamma-ray emission

A non-destructive, in situ current normalized particle induced gamma-ray emission methodology has been standardized for quantification of fluorine (F) in soil samples from Punjab state, India. The samples were irradiated using 4 MeV proton beam from the Folded Tandem Ion Accelerator at BARC, Mumbai. The gamma rays of energies 197 and 478 keV arising from ¹⁹F(p, p′γ)¹⁹F and ⁷Li(p, p′γ)⁷Li nuclear reactions were measured using high resolution gamma-ray spectrometry. The concentration of fluorine in soil samples was found to vary between 414 and 5,746 mg kg^?1.