Multielement analysis of a municipal landfill leachate with total reflection X-ray fluorescence (TXRF). A comparison with ICP-OES analytical results

A complete analysis of a landfill leachate coming from a landfill site of several years old was performed with a total reflection X-ray fluorescence (TXRF) spectrometer in comparison with an inductively coupled plasma optical emission spectroscopy (ICP-OES). The results of the two analytical techniques are compared and advantages and drawbacks emphasized. The TXRF analytical technique appears a reliable, economic, rapid and simpler technique for the everyday monitoring of the composition of the landfill leachate before the purification treatment and after the treatment to check the quality of the resulting purified water. The TXRF and the ICP-OES analytical techniques were also employed in the analysis of three groundwater samples.     

Crystallographic studies of the role of Mg as a stabilizing impurity in β-Ca3(PO4)2. II. Refinement of Mg-containing β-Ca3(PO4)2

The crystal structures of five samples of Mg-containing β-tricalcium orthophosphate, β-Ca₃(PO₄)₂, have been refined and the Mg-impurity distribution has been examined. Typically, ～7500 reflections were measured and merged into a unique set of ～2500. Least-squares refinements with anisotropic temperature factors (and third cumulants for some atoms) produced weighted residuals, R_w(F), in the region of 0.02 to 0.04. Three of the five cation sites are always completely filled with calcium ions, a fourth site with Ca and Mg ions, and the fifth site contains Ca, Mg, and vacancies. Local order may exist because the sizes of the coordinations about the two Mg-containing cation sites are directly related by the orientation of phosphate group P(2)O₄ such that a small ion in one site favors the incorporation of a small ion in the other site.     

Isotopic and hydrochemical approach to the functioning of an aquifer system in the region of Marrakech (Morocco)

A geochemical and isotopic (water and dissolved sulphate) study was performed on groundwater in the region of Marrakech, Morocco, with the aim of better understanding the regional hydrogeological system in order to improve water resources management. Significant differences in stable isotope contents and chemical compositions were observed between groundwater collected in the northern part of the region (Jbilets massif), where the basement schists outcrop, and that sampled in the southern part (Haouz basin), where the basement schists are overlaid by Plio-Quaternary deposits. The stable isotope composition of the groundwater showed that in the southern part the aquifer is mainly recharged from high-altitude precipitation over the High-Atlas Mountains, which may reach 600 mm per year or more, whereas, in the northern part, it is only recharged by lower-altitude local precipitation, which does not exceed 240 mm per year. Because of this limited supply, the groundwater flux in the northern compartment is much lower than in the southern compartment. This affects the water-rock interaction and the modalities of groundwater mineralization: the schist alteration is more developed in the southern compartment than in the northern one, leading to different behaviours of the conservative elements dissolved in groundwater. The observed geochemical and isotopic zonation of the studied area corresponds to a hydrogeological compartmentalisation, where the wells located in the north of the area generally produce less water than those located in the south of the area.     

Thermal analysis (TG-DTA) and drift spectroscopy applied to investigate the evolution of humic acids in forest soil at different vegetation stages

Humic acids (HAs) extracted from soils developed under two Norwegian spruce (Picea abies, (L.) Karst) subalpine forests of northern Italy were characterized using chemical, thermal (TG-DTA) and spectroscopic (DRIFT) analyses. The samples were taken from five sites which differed in orientation (northern and southern exposure) and vegetal cover at different old age: grassland, regeneration, immature and mature stands. In general, the thermal patterns of HAs were similar (three exothermic reactions appeared around at 300, 400 and 500°C) in both sites in grasslands and regeneration while a considerable modification appeared in HA from stands of different age at northern and southern exposure site. DRIFT spectroscopy confirmed the differences observed through TG-DTA analysis. In particular the main structural changes were ascribed to modification of carbonyl group and of CH stretching in aliphatic components in each HAs from different sites.     

Heavy metal concentrations in soil and wild plants growing around Pb-Zn sulfide terrain in the Kohistan region, northern Pakistan

This study investigates the soil and wild plants of the Pb-Zn sulfide bearing mineralized zone of Indian plate (IP) in the Pazang and Lahor sites, Kohistan region, northern Pakistan. Soil and plants were analyzed for major cations (Na, K, Ca, Mg, Fe, Mn) and heavy metals (Pb, Zn, Cd, Cu, Cr, Ni, Co) concentrations by using atomic absorption spectrometer. Metal concentrations were used to quantify pollution contamination factors such as pollution load index (PLI) and plant bioaccumulation in soil and plants developed in mineralized zones in the Lahor and Pazang sites and an unmineralized zone (reference sites) of the Besham area. Soil and plants of the mineralized zone and surrounding areas have higher heavy metal (HM) contamination (P < 0.01) as compared to the reference site, which can be attributed to the dispersion of metals due to mining. Furthermore, in mineralized zones, the Lahor site was more contaminated than the Pazang site. This high HM contamination may pose potential threats to local communities of Kohistan region. The results also showed that plant species (Plectranthus rugosus, Rumex hastatus, Fimbristylis dichotoma, Heteropogon conturtus and Myrsine Africana) were the best HM accumulators.     

Assessment of metal contamination in an urban drainage system (using water and tilapia, Oreochromis spp.) in view of human health effect. A case study of some selected communities in Cape Coast township in Ghana

This research work aimed at studying the metal content of water and tilapia fish sample, Oreochromis spp., from a wastewater-fed pond around the University of Cape Coast community using instrumental neutron activation analysis. The metals studied were Al, As, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, V and Zn. In the water samples the order of elemental concentrations at sampling point 1, in ??g/g, was K (75.96?±?0.92), Na (18.52?±?0.35), Al (6.00?±?0.89), Mn (3.28?±?0.44), As (3.08?±?0.40), Mg (1.56?±?0.17), Ca (0.70?±?0.08), Cu (0.54?±?0.08) and V (0.04?±?0.01). Co, Cr, Fe and Zn were below detection limits of INAA. The order of elemental concentrations in the water at point 2 was as follows: Na (4.99?±?0.14), K (4.82?±?0.89), Mn (4.40?±?0.53), Mg (2.92?±?0.37), Al (1.98?±?0.21), As (0.69?±?0.10), Ca (0.24?±?0.07) and V (0.23?±?0.06) with Co, Cr, Cu, Fe and Zn falling below the detection limit of INAA. The concentrations recorded for Al, As, Cu and Mn in the water samples were all above WHO permissible limits. The mean levels of heavy metals in the soft tissue of tilapia was of the order: K?>?Mg?>?Fe?>?Ca?>?Na?>?Al?>?Mn?>?Zn?>?V?>?Cu?>?Cr?>?Co. Arsenic was below detection limit. The transfer factor values calculated for the metals Al, Ca, K, Mg, Mn, Na and V were all greater than one indicating movement of metals from the water column to the tilapia species. The hazard index (HI) calculated for Al, Fe, Mn and V suggested possible occurrence of adverse health effects (HI?>?1) where as the HI value obtained for Cr, Cu and Zn (i.e., HI?<?1) suggested unlikely adverse effects occurring.     

Titania sol–gel-derived tyrosinase-based amperometric biosensor for determination of phenolic compounds in water samples. Examination of interference effects

For detection of phenolic compounds in environmental water samples we propose an amperometric biosensor based on tyrosinase immobilized in titania sol-gel. The analytical characteristics toward catechol, p-cresol, phenol, p-chlorophenol, and p-methylcatechol were determined. The linear range for catechol determination was 2.2 x 10(-7)-1.3 x 10(-5) mol L(-1) with a limit of detection of 9 x 10(-8) mol L(-1) and sensitivity 2.0 x 10(3) mA mol(-1) L. The influence of sample matrix components on the electrode response was studied according to Plackett-Burman experimental design. The potential interferents Mg(2+), Ca(2+), HCO3(-), SO4(2-), and Cl(-), which are usually encountered in waters, were taken into account in the examination. Cu(2+) was also taken into account, because CuSO(4) is sometimes added to a water sample, as a preservative, before determination of phenolic compounds. It was found that among the ions tested only Mg(2+) and Ca(2+) did not directly affect the electrode response. The developed biosensor was used for determination of catechol in spring and surface water samples using the standard addition method.     

Investigation of methyl tert-butyl ether levels in river-, ground-, and sewage-waters analyzed using a purge-and-trap interfaced to a gas chromatograph-mass spectrometer

River water collected from 27 sites in 21 rivers, groundwater from 66 sites in 34 cities, and 2 sewage plants in the Niigata Prefecture, Japan (total 301 samples) were analyzed for methyl tert-butyl ether (MTBE) using an improved purge-and-trap-GC-MS method. The amount of MTBE found in water samples from the 27 river sites ranged from 0.003 to 5.3 microg l(-1). MTBE was found in all 27 sites during winter but it was found at only 9 sites and 14 sites, respectively, during the summer. MTBE was found most frequently (in 21 sites) at levels ranging from 0.003 to 0.009 microg l(-1) during February. The highest levels of MTBE were always found in the samples collected from the same site. The amount of MTBE found in sewage water samples ranged from <0.003 to 0.025 microgl(-1). No significant differences were observed between the amounts of MTBE recovered from inflow and outflow waters. Relatively high levels (0.02-0.034 microg l(-1) ) of MTBE were found in January at two sites, which were located on the upper course of the Shinano River. MTBE levels ranged from 0.004 to 0.035 microgl(-l) and from 0.005 to 0.041 microgl(-1) at the mouths of the Shinano River and Agano River, respectively. The levels of MTBE in groundwater collected from 66 sites in 34 cities in Niigata Prefecture ranged from <0.003 to 5.9 microg l(-1).     

Understanding the groundwater dynamics in the Southern Rift Valley Lakes Basin (Ethiopia): multivariate statistical analysis method, oxygen (δ 18O) and deuterium (δ 2H)

Multivariate statistical analysis is very important to classify waters of different hydrochemical groups. Statistical techniques, such as cluster analysis, can provide a powerful tool for analyzing water chemistry data. This method is used to test water quality data and determine if samples can be grouped into distinct populations that may be significant in the geologic context, as well as from a statistical point of view. Multivariate statistical analysis method is applied to the geochemical data in combination with δ ¹⁸O and δ ²H isotopes with the objective to understand the dynamics of groundwater using hierarchical clustering and isotope analyses. The geochemical and isotope data of the central and southern rift valley lakes have been collected and analyzed from different works. Isotope analysis shows that most springs and boreholes are recharged by July and August rainfalls. The different hydrochemical groups that resulted from the multivariate analysis are described and correlated with the geology of the area and whether it has any interaction with a system or not.     

Elemental composition of drinking water supplies in three states in Southeastern Nigeria

The levels of some trace elements; Co, Mn, Cu, Zn, Cr, Cd, Pb, Fe, Hg, Se, As, Ni and minor elements; Na, K, Ca and Mg were determined in public drinking water supplies (public taps and groundwaters) in three states in Southeastern Nigeria using energy dispersive X-ray fluorescence spectrometry (EDXRF) and flame atomic absorption spectrometry (FAAS). The mean levels of most of the trace elements in the groundwater samples were below the World Health Organization (WHO) drinking water quality limits, the only exception being Hg whose mean value of 3.69 μg/l exceeded the WHO limit of 1.0 μg/l. Violations of the WHO limits were also observed for Fe, Zn, Se and Pb in some of the groundwater samples. In the public tap samples only Hg violated the WHO limit.     

电感耦合等离子体原子发射光谱法(ICP-OES)测定地下水中多种元素

应用电感耦合等离子体原子发射光谱法(ICP-OES)测定地下水中钾、钠、钙、镁、铁、锰元素的含量,使用分光光度法测定氟的含量,测定的相对标准偏差为0.7%~2.8%,加标回收率为92.1%~105.2%。结果表明,大部分地区地下水中钠和氟化物的含量均偏高,常量与微量元素的组成含量差别不大。     

A method for risk assessment for three contaminated sites in northern Italy

A stepwise human health risk assessment procedure carried out using American Society for Testing and Materials methodology was applied to three contaminated sites located in northern Italy: an uncontrolled landfill, an abandoned industrial site and an industrial waste contaminated land. Two different tiers of analysis were performed by means of the analytical model RBCA Tool Kit and the numerical model API-DSS, respectively. The latter was applied according to both a deterministic and a probabilistic risk analysis. The comparison of the two approaches highlighted the great benefit provided by probabilistic analysis for the risk assessment based on site specific parameters and more complex models, in particular for groundwater exposure route. Finally, the risk-based site specific target levels were compared to the generic regulatory threshold limits fixed by the Italian regulation. The comparison showed the regulatory limits generally too restrictive for non-carcinogenic substances but less protective for carcinogenic chemicals, outlining the need of a site-specific risk assessment especially for carcinogenic substances.     

The application of Westcott Formalism k0 NAA method to estimate short and medium lived elements in some Ghanaian herbal medicines complemented by AAS

The epithermal neutron shape factor, α of the inner and outer irradiation sites of the Ghana Research Reactor-1 (GHARR-1) was determined obtaining results of 0.105 for the inner (Channel 1) Irradiation site and 0.020 for the outer (channel 6) irradiation site. The neutron temperatures for the inner and outer irradiation sites were 27 °C and 20 °C, respectively. The α values used in Westcott Formalism k₀ INAA was applied to determine multi elements in 13 Ghanaian herbal medicines used by the Centre for Scientific Research into Plant Medicine (CSRPM) for the management of various diseases complemented by Atomic Absorption Spectrometry. They are namely Mist. Antiaris, Mist. Enterica, Mist. Morazia, Mist. Nibima, Mist. Modium, Mist. Ninger, Mist Sodenia, Mist. Tonica, Chardicca Powder, Fefe Powder, Olax Powder, Sirrapac powder and Lippia Tea. Concentrations of Al, As, Br, K, Cl, Cu, Mg, Mn, Na and V were determined by short and medium irradiations at a thermal neutron flux of 5×10¹¹ ncm⁻² s⁻¹. Fe, Cr, Pb, Co, Ni, Sn, Ca, Ba, Li and Sb were determined using Atomic Absorption Spectrometry (AAS). Ba, Cu, Li and V were present at trace levels whereas Al, Cl, Na, Ca were present at major levels. K, Br, Mg, Mn, Co, Ni, Fe and Sb were also present at minor levels. Arsenic was not detected in all samples. Standard Reference material, IAEA-V-10 Hay Powder was simultaneously analysed with samples. The precision and accuracy of the method using real samples and standard reference materials were evaluated and within ±10% of the reported value. Multivariate analytical techniques, such as cluster analysis (Q-mode and R-mode CA) and principal component analysis (PCA)/factor analysis (FA), have been applied to evaluate the chemical variations in the herbal medicine dataset. All the 13 samples may be grouped into 2 statistically significant clusters (liquid based and powdered herbal medicines), reflecting the different chemical compositions. R-mode CA and PCA suggest common sources for Co, Mg, Fe, Ca, Cr, Ni, Sn, Li and Sb and Na, V, Cl, Mn, Al, Br and K. The PCA/FA identified 3 dominant factors as responsible for the data structure, explaining 84.5% of the total variance in the dataset.     

Factors governing the substitution of La3+ for Ca2+ and Mg2+ in metalloproteins: a DFT/CDM study

Trivalent lanthanide cations are extensively being used in biochemical experiments to probe various dication-binding sites in proteins; however, the factors governing the binding specificity of lanthanide cations for these binding sites remain unclear. Hence, we have performed systematic studies to evaluate the interactions between La3+ and model Ca2+ - and Mg2+ -binding sites using density functional theory combined with continuum dielectric methods. The calculations reveal the key factors and corresponding physical bases favoring the substitution of trivalent lanthanides for divalent Ca2+ and Mg2+ in holoproteins. Replacing Ca2+ or Mg2+ with La3+ is facilitated by (1) minimizing the solvent exposure and the flexibility of the metal-binding cavity, (2) freeing both carboxylate oxygen atoms of Asp/Glu side chains in the metal-binding site so that they could bind bidentately to La3+, (3) maximizing the number of metal-bound carboxylate groups in buried sites, but minimizing the number of metal-bound carboxylate groups in solvent-exposed sites, and (4) including an Asn/Gln side chain for sites lined with four Asp/Glu side chains. In proteins bound to both Mg2+ and Ca2+, La3+ would prefer to replace Ca2+, as compared to Mg2+. A second Mg2+-binding site with a net positive charge would hamper the Mg2+ --> La3+ exchange, as compared to the respective mononuclear site, although the La3+ substitution of the first native metal is more favorable than the second one. The findings of this work are in accord with available experimental data.     

Radioactive contamination of groundwater at the Andreeva Bay Shore Technical Base,Northwest Russia

The Andreeva Bay Shore Technical Base is one of the largest, most contaminated nuclear legacy sites in Northwest Russia. Radioactive contamination at the site stems from servicing and maintenance activites for Russian Northern Fleet nuclear submarine. Studies of groundwater contamination have been conducted using measurements taken at different boreholes around the site. Results indicate that groundwater contamination has occurred in some areas of the Andreeva Bay facility. These areas are primarily located near Building 5 where accidental releases occurred in 1982 during storage of spent nuclear fuel (SNF) and near the liquid and solid radioactive waste (LRW and SRW) storage facilities which have been infiltrated by precipitation waters.     

Health risk assessment of heavy metals and their source apportionment in drinking water of Kohistan region, northern Pakistan

The present study was conducted to investigate heavy metal (Cu, Co, Cr, Mn, Ni, Pb, Zn and Cd) concentrations of drinking water (surface water and groundwater) samples in Kohistan region, northern Pakistan. Furthermore, the study aimed to ascertain potential health risk of heavy metal (HM) concentrations to local population. HM concentrations were analyzed by using graphite furnace atomic absorption spectrometer (Perkin Elmer, AAS-PEA-700) and were compared with permissible limits set by Pakistan Environmental Protection Agency (Pak EPA) and World Health Organization (WHO). Based on HM concentrations the health risk assessment like chronic daily intake (CDI) and hazard quotient (HQ) was calculated. The values for CDI were found in the order of Zn > Cu > Mn > Pb > Cr > Ni > Cd > Co and the values of HQ were < 1 for all HM in drinking water samples indicating no health risk. Furthermore, multivariate statistical analysis like one-way ANOVA, inter-metal correlation, cluster analysis (CA) and principal component analysis (PCA) results revealed that geogenic and anthropogenic activities were major sources of water contamination in Kohistan region.     

Characterizing the groundwater renewability and evolution of the strongly exploited aquifers of the North China Plain by major ions and environmental tracers

The Yongding River Alluvial Fan is a northwestern part of the North China Plain, at which Beijing is located. Since 1950 and especially 1970, excessive groundwater exploitation has resulted in a significant drop of groundwater table, and it’s believed that groundwater will be intensively used continuously in the future. It’s essential to reveal the renewability and the evolution of the groundwater for reasonable management, which was achieved based on the analyses of the major ions and environmental tracers in groundwater. According to the dating results of ³H, CFCs, and ¹⁴C, the age of the shallow and deep groundwater was from <5 to 60 a and from <4,000 to >12,000 a, respectively. The recharge rate determined by the groundwater age generally had a decreasing trend from the NW (0.40–1.44 m/a) to the SE (0.07–0.48 m/a). Na and HCO₃ accumulated from the NW to the SE and the latter was the dominant anion. Chemical modification occurred progressively along the flow paths. The water type of the shallow and deep groundwater changed from Ca–Mg–HCO₃ to Na–HCO₃ and from Ca–Mg–HCO₃ to Ca–Na–Mg–HCO₃ and Na–Ca–Mg–HCO₃ from the NW to the SE, respectively. The shallow groundwater was vulnerable and susceptible to contamination scattered throughout the region, which would probably further extend to the deep groundwater because of the vertical groundwater flow especially through the preferential pathways due to their increasing hydraulic connections.     

电解液阴极大气辉光放电原子发射光谱检测水硬度

在自制的电解液阴极大气辉光放电原子发射谱(ELCAD-AES)装置上,研究了钙镁标准溶液的特征发射光谱,定量检测了Mg和Ca的含量,两元素的检出限分别为0.2mg/L和0.8mg/L。通过准确性和加标回收实验,以及与乙二胺四乙酸二钠盐络合滴定(EDTA滴定)法测量结果的比较,证明了ELCAD-AES方法测量水硬度的可靠性。测定了沸腾前后的自来水和地下水,以及湖水中Mg和Ca的含量,获得了这些水样的硬度。所建立的ELCAD-AES方法可用于水体硬度或金属元素的快速在线监测。     

Quelques aspects de la connaissance par l'analyse thermique,des residus d'evaporation de solutions mixtes d'hydrogenocarbonates de calcium et de magnesium

Journal of Thermal Analysis and Calorimetry - Les difficultés de l'étude des résidus d'évaporation de solutions mixtes de Ca(HCO3)2 et de Mg(HCO3)2, par les...     

改进的离子色谱系统监测重庆嘉陵江水质（英文）

The w ater quality monitoring operation to evaluate the w ater quality of polluted river is an extremely im po rtant task fo r the river-w atershed m anagem ent/co ntro l based o n the enviro nm ental po licy.In this study,the no vel,sim ple and co nvenient w ater quality m o nito ring o f Jialing-River in Cho ngqing,China w as carried o ut using an advanced io n chro m ato graphy(IC) co nsisting o f io n-ex clusio n/catio n-ex change chro m ato graphy(IEC/CEC) with conductivity detection for determining simultaneously the common anions such as SO 2 4,Cl,and NO 3 and the catio ns such as Na +,NH + 4,K +,Mg 2 +,and Ca 2 +,the ion-exclusion chromatography(IEC) w ith visible detectio n fo r determ ining sim ultaneo usly the nutrient co m po nents such as pho sphate and silicate io ns,and the IEC w ith the enhanced co nductivity detectio n using a po st co lum n o f K +-fo rm catio n-ex change resin fo r determ ining HCO 3-alkalinity as an ino rganic-carbo n so urce fo r bio m ass synthesis in bio lo gical reactio n pro cess under the aero bic co nditio ns.Acco rding to the io nic balance theo ry betw een the to tal equivalent co ncentratio ns o f anio ns and catio ns,the w ater quality evaluatio n o f the Jialing-River w aters taking at different sam pling sites in Cho ngqing m etro po litan area w as carried o ut using the advanced IC system.As a result,the effectiveness o f this no vel w ater quality m o nito ring m etho do lo gy using the IC system w as dem o nstrated o n the several practical applicatio ns to a typical bio lo gical sew age treatm ent plant o n Jialing-River o f Cho ngqing.