On-site Sampling Research Articles

Distribution of Octylphenol and Nonylphenol in the Sediment of Kaohsiung Harbor, Taiwan

In this research we have set twenty survey stations in Kaohsiung Harbor to conduct on-site sampling and monitoring of sediments. The aim is to analyze their particle diameters, water content, organic matter (OM), total organic carbon (TOC), 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP) in order to understand the concentration distributions and sources of 4-NP and 4-t-OP in the Harbor sediments. The results indicate that the concentrations of 4-NP and 4-t-OP fall within the ranges of 18–27,882 ng/g dw (average 101±3,580 ng/g dw) and 1.1–1,150 ng/g dw (average 44±174 ng/g dw). The concentrations of 4-NP and 4-t-OP in the river mouths’ sediments are apparently higher and gradually decrease nearer the Harbor, especially the 4-NP of the mouth of Jen-Gen River (average 13,236±9,204 ng/g dw) and the 4-t-OP of the mouth of Love River (average 676±411 ng/g dw). This pattern shows that industrial wastewater and untreated municipal wastewater/sewage are the major sources. The correlation analysis indicates that TOC and OM play an important role in controlling the concentration level of 4-NP and 4-t-OP in the sediments. However, in the pollution hotspot, the direct inflow of pollutants would be the crucial factor that determines the concentration and distribution of organic pollutants in sediments.

Construction of a portable sample preparation device with a magnetic poly(methacrylic acid-co-ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples.

A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high-performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3-0.8 and 1.0-2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3-101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on-site simultaneous sampling, purification, and preconcentration within a single step.

Design of X-Ray Fluorescence Spectrum Software Based on Linux

According to the research on analysis software of X fluorescent spectrum under the Linux system, a new algorithm of X fluorescence analyzer has been brought up: use the method of energy dispersive X fluorescence analysis, based on the software that can analyze the material composition under the control of ARM - Linux touch screen. This paper fixes on developing software of X fluorescence analyzer; realize the collection and analysis of multi-channel spectrum data, data storage, sample analysis, qualitative and quantitative analysis of the on-site samples, and the research and implementation of corresponding algorithm.

Economic Value and Impact of Visitation to Cape Hatteras National Seashore: Addressing Onsite Sampling

We examine recreation demand, economic value, and visitor expenditure patterns for Cape Hatteras National Seashore (CHNS) on the Outer Banks, North Carolina. CHNS is one of the largest protected barrier islands on the East Coast and is remote, accessible only by ferry or a single stretch of road running along the island chain. We present a unified approach to correcting for avidity bias due to onsite sampling in descriptive statistics and demand modeling, extending the Shaw (1988) correction to the Generalized Negative Binomial model. We demonstrate the effects of avidity bias in descriptive statistics; correcting expenditure estimates increases economic impact by 17%, reflecting larger magnitude in spending patterns of less avid users that live further from CNHS. Correcting for avidity bias in recreation demand lowers welfare estimates, which are still, however, quite large at $403/household, per trip (2002 USD).

Development of needle trap technology for on-site determinations: active and passive sampling.

This study presents a thorough evaluation of new prototypes of extended tip needle trap devices (NT), as well as their application to in situ sampling of biological emissions and active/passive on-site sampling of indoor air. A new NT prototype was constructed with a side hole above the sorbent and an extended tip that fits inside the restriction of the narrow neck liner to increase desorption efficiency. New prototype needles were initially packed with divinylbenzene particles at SGE Analytical Science for the purpose of studying biogenic emissions of pine trees. Prior to their final application, they were evaluated in terms of robustness after multiple use (n > 10), as well as amount extracted of volatile organic compounds (VOCs). An ANOVA test for all the probes showed that at a 95% level of confidence, there were not statistical differences observed among the 9 NTs tested. In addition, the needles were also packed in laboratory with synthesized highly cross-linked PDMS as a frit to immobilize carboxen (Car) particles for spot sampling. For passive sampling, the needles were packed with Car particles embedded in PDMS to simplify calculations in passive mode. The use of NTs as spot samplers, as well as a passive sampler under controlled conditions in the laboratoryyielded a relative standard deviation of less than 15%. Finally, a new, reusable and readily deployable penlike diffusive sampler for needle traps (PDS-NT) was built and tested. Application of the PDS-NT in combination with NT-spot sampling toward the analysis of indoor air in a polymer synthesis laboratory showed good agreement between both techniques for the analyte studied, yielding averages of 0.03 and 0.025 ng/mL of toluene, respectively.

Microextraction techniques in breath biomarker analysis.

Breath volatile organic compound analysis may open a non-invasive window onto (patho)physiological and metabolic processes in the body. Breath tests require controlled sampling with respect to different breath phases and on-site and point-of-care applicability. Microextraction techniques such as solid phase microextraction (SPME) or needle-trap microextraction (NTME) meet these requirements. Small sample volumes and fast and controlled sample preparation combine on-site sampling and pre-concentration in one step. Detection limits in the low ppbV range and fast and simple processing facilitate the application of distribution-based SPME for screening and targeted analysis. Exhaustive NTME has shown further advantages such as fast and automated sampling, improved stability and reproducibility with improved detection limits. Combinations of different sorbents and thermal expansion desorption have shown most promising properties when applied to water saturated breath samples. This article addresses major challenges and advantages of microextraction techniques in breath analysis. Important progress, current applications and future trends are discussed.

Modeling Willingness to Pay for Coastal Tourism Resource Protection in Ko Chang Marine National Park, Thailand

The value of non-market resources is important information for the nature-based park investment and management. In this paper, we estimate visitors' willingness to pay (WTP) an entrance fee for beach resource protection of the Ko Chang Marine Park in Thailand using a standard contingent valuation method of a single-bounded (SB) and double-bounded (DB) dichotomous choice format. An on-site stratified sampling survey of 409 beach visitors was conducted at the park along the White Sand Beach shoreline. By comparing the two survey methods, the average WTP for a Thai beach visitor is about $12.01 under the SB elicitation survey and $7.27 per adult per visit under the DB elicitation method, respectively. It turns out that the foreign visitors' WTP is twice as much as that of Thai visitors' WTP. These can be translated to the lower and upper bounds of an aggregated value ranging between $10.33 million and $17.41 million per annum. The policy implications for the park management are addressed.

Prediction of global bending stiffness of timber beams by local sampling data and visual inspection

The results of visual inspection according to UNI 11119:2004 and bending tests made on 20 old chestnut (Castanea sativa Mill.) beams according to EN 408:2010 were statistically analyzed in order to provide a consistent and feasible procedure to predict their modulus of elasticity (MOE) in bending. Local data obtained from smaller size specimens was used for the prediction of the global mechanical properties of full structural size members and compared with the results of mechanical tests. The prediction models took into account the visual strength classes and the influence of defects on the determination of the MOE. Moreover, random sampling was considered in order to demonstrate the possibility of using smaller representative samples, thus avoiding excessive need of removal of on-site samples and allowing for a smaller number of mechanical tests. The models using random sampling predicted the behavior of full size scale elements accurately, with strong correlations to the experimental results (coefficient of determination r 2 ranging from 0.70 to 0.79) and a percentage error lower than 20 %, thus allowing a reliable estimation of mechanical characteristics of existing timber members with a combination of visual inspection and local sampling.

Monitoring of heavy metal particle emission in the exhaust duct of a foundry using LIBS

Heavy metals have long been known to be detrimental to human health and the environment. Their emission is mainly considered to occur via the atmospheric route. Most of airborne heavy metals are of anthropogenic origin and produced through combustion processes at industrial sites such as incinerators and foundries. Current regulations impose threshold limits on heavy metal emissions. The reference method currently implemented for quantitative measurements at exhaust stacks consists of on-site sampling of heavy metals on filters for the particulate phase (the most prominent and only fraction considered in this study) prior to subsequent laboratory analysis. Results are therefore known only a few days after sampling. Stiffer regulations require the development of adapted tools allowing automatic, on-site or even in-situ measurements with temporal resolutions. The Laser-Induced Breakdown Spectroscopy (LIBS) technique was deemed as a potential candidate to meet these requirements.On site experiments were run by melting copper bars and monitoring emission of this element in an exhaust duct at a pilot-scale furnace in a French research center dedicated to metal casting. Two approaches designated as indirect and direct analysis were broached in these experiments. The former corresponds to filter enrichment prior to subsequent LIBS interrogation whereas the latter entails laser focusing right through the aerosol for detection. On-site calibration curves were built and compared with those obtained at laboratory scale in order to investigate possible matrix and analyte effects. Eventually, the obtained results in terms of detection limits and quantitative temporal monitoring of copper emission clearly emphasize the potentialities of the direct LIBS measurements.

Factory-level measurements on CO2 emission factors of cement production in China

Cement is a primary component of concrete and is consumed extensively for construction and transportation infrastructures worldwide. Cement is largely produced and consumed locally but has global impact in terms of both energy consumption and greenhouse gas emissions. China is both the largest producer of cement and the biggest emitter of CO2 emissions in the world. It has been widely recognized that uncertainties of China's CO2 emissions were poorly quantified and clear discrepancies can be identified among different sources. These discrepancies arise from many uncertainties, including system boundary and statistical standards, availability of production data (especially for the clinker and cement outputs), and emission factors. We argue that the emission factors (EFs, either default values or adjusted ones) are the most important here and highlight the importance of clearly defining the CO2 accounting and reporting boundaries for determining the emission factors. We therefore developed a factory-level measurement for different types of clinker and cement production, primarily using onsite surveys and sampling, with the objective of distinguishing process-, combustion- and electricity-related emission factors. on a factory level. It is a bottom-up CO2 emission inventory for China using the uniform formula and calculators and the first time factory-level sampling method (BFSM) based on three tiers of production lines, provincial and national integrations. Our results indicate that China's carbon emissions from cement production might be overestimated in the previous estimates because they overlooked the technology transition from the wet process to the dry process, differences in lime content and clinker-to-cement ratios, raw materials and fuels substitutions, and usages of blend additives. (C) 2014 Elsevier Ltd. All rights reserved.

Performance of a Clayey Soil Used for Landfill Liner Material in a Tannery Sludge Disposal Site for Chromium Attenuation

AbstractLaboratory and field investigations were performed in this study to evaluate the efficacy of a fine-grained clayey soil as a low-cost primary liner material for attenuating chrome-laden leachate from a chrome sludge disposal site of a tannery plant. On-site soil and water samples exhibited the existence of Cr6+ in excess of the permissible limit as prescribed for discharging inland surface water. Batch adsorption kinetic results showed that Cr6+ removal in equilibration increases with elevation of temperature. The soil mass in use exhibited reasonable capability of adsorbing Cr6+, and the kinetic results demonstrated that the pseudo second-order kinetic model fitted reasonably well. The triaxial test results revealed a maximum permissible overburden pressure of 3.0 kN/m2 from deposited waste if the clayey soil is to be used as a liner material. The use of a compacted clay soil with a thickness of 600 mm is recommended for effective containment of leachate transmission with regard to a leachable h...

Investigation of off-site airborne transport of lead from a superfund removal action site using lead isotope ratios and concentrations

Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil samples were used to investigate the potential for off-site air transport of Pb from a former white Pb processing facility to neighboring residential homes in a six block area on Staten Island, NY. Surface and subsurface soil samples collected on the Jewett White Pb site were found to range from 1.122 to 1.138 for 206Pb/207Pb and 2.393 to 2.411 for 208Pb/207Pb. The off-site surface soil samples collected from residential backyards, train trestle, near site grass patches and background areas varied from 1.144 to 1.196 for 206Pb/207Pb and 2.427 to 2.464 for 208Pb/207Pb. Two soil samples collected along Richmond Terrace, where Jewett site soils accumulated after major rain events, varied from 1.136 to 1.147 for 206Pb/207Pb and 2.407 to 2.419 for 208Pb/207Pb. Lead concentration for on-site surface soil samples ranged from 450 to 8000ug/g, on-site subsurface soil samples ranged from 90,000 to 240,000ug/g and off-site samples varied from 380 to 3500ug/g. Lead concentration and isotopic composition for the Staten Island off-site samples were similar to previously published data for other northeastern US cities and reflect re-suspension and re-mobilization of local accumulated Pb. The considerable differences in both the Pb isotopic composition and Pb concentration of on-site and off-site samples resulted in the ability to geochemically trace the transport of particulate Pb. Data in this study indicate minimal off-site surface transport of Pb from the Jewett site into the neighboring residential area.

Geochemical Assessment of Two Excavated Mass Graves in Rwanda: A Pilot Study

Necrosols are a unique category of anthropogenic soils that are associated with excavated cemeteries or graveyards. In spite of the growing number of cemeteries and burial sites found across urban and rural areas globally, scientific information regarding the contamination potential of this category of soils is relatively scarce and not properly understood. The purpose of this study is to fill this gap by assessing the contamination significance of trace metal contents in the necrosols associated with two excavated mass graves in Rwanda. For this preliminary geochemical investigation, cemetery soil samples were collected from two excavated mass graves in the Murambi memorial site, Rwanda, and analyzed for trace and major element concentrations. The enrichment factor (EF), chemical index of alteration (CIA), and contamination status of necrosol samples was determined in comparison with the offsite area. The results revealed that the average EF values for both onsite and offsite samples were generally within the class of natural background with only six onsite samples having higher EF values than the offsite or background area. Possible reasons for the progressive depletion of the selected trace element onsite are the relatively low anthropogenic activities and higher weathering intensity of the necrosols in comparison with the background area over time. Even though the mean onsite CIA values for the necrosols were slightly higher than the background area, the index further confirmed that both the necrosols and offsite samples were significantly altered to kaolinic degree. From the resulting pollution index values (PI Nemerow), it can be inferred that the Murambi necrosols were within the range of 0.84 and 1.82, corresponding to the precaution and slightly polluted domain. The current contamination status of the necrosols is likely to have been caused as a result of the anthropogenic input of Cr and Pb onsite relative to the offsite area.

Total mercury in snow and ice samples from Canadian High Arctic ice caps and glaciers: A practical procedure and method for total Hg quantification at low pg g− 1 level

A newly developed procedure and method for studying total Hg (THg) in the High Arctic glaciers and ice caps, including container type selection, on-site sampling, sample protection and storage, and sample decontamination is reported in this study. Two analytical systems for THg quantification were also compared to confirm the accuracy and reproducibility.This study found that container types, storage time, sample protection from exposure to light and environment are all important for precise quantification of THg in snow and ice samples from the Canadian High Arctic glaciers and ice caps.With this newly developed procedure and method, we retrieved 28-year and 73-year archives for atmospheric THg deposition from Mt. Oxford and Agassiz Ice Cap respectively. Our results show that snow and ice samples contain THg concentrations varying from sub pgg−1 to low pgg−1. Comparison of THg concentration trends and fluxes from the two sites demonstrates that quantification of THg from the two locations with similar altitudes and latitudes can be reproducible, which suggests that historical THg information from atmospheric deposition can be preserved in snow and ice in the glaciers and ice caps. The high reproducibility of results achieved by this procedure and method, in return, confirmed its suitability for studies of THg in snow and ice samples from ice caps and glaciers.

Modelling VOC source impacts on high ozone episode days observed at a mountain summit in Hong Kong under the influence of mountain-valley breezes

A top-down approach to evaluate high ozone (O3) formation, attributed to different emission sources, is developed for anti-cyclonic conditions in a region of Hong Kong influenced by meso-scale circulations. A near-explicit photochemical model coupled with the Master Chemical Mechanism (MCMv3.2) is used to investigate the chemical characteristics in the region. Important features have been enhanced in this model including the photolysis rates, simulated by the National Center for Atmospheric Research (NCAR) Tropospheric Ultraviolet and Visible (TUV) Radiation Model, as well as hourly variation of Volatile Organic Compound (VOC) concentration input from on-site sampling. In general, the combined model gives a reasonably good representation of high O3 levels in the region. The model successfully captured a multi-day O3 event in the autumn of 2010. Source apportionment via Positive Matrix Factorization (PMF) was carried out on the sampled VOC data, to determine the major sources in the region. Based on the outcomes of the PMF source apportionment, a sensitivity analysis using the developed photochemical model was conducted and used to estimate O3 reduction under different source removal regimes. Results indicate that vehicular emissions are the dominant VOC source contributing to O3 formation. This study has demonstrated a potentially efficient secondary pollutants control methodology, using a combined field measurements and modelling approach.

Assessing Human Carcinogenic Risk of Heavy Metal Exposure in a Tourist Area

Environmental safety in a tourism area is one of the basic security for tourists health. Thus, it is of great significance to assess the heavy metal-based potential health risk of a tourism area and its surrounding areas. This study mapped the carcinogenic risk of heavy metal polluted soil in a tourism area of XX City through procedures including on-site sampling, exposure dose estimation, toxicity assessment, carcinogenic risk calculation, and GIS (Geographic Information System) spatial interpolation. Results show that the soil of the tourism area was contaminated by heavy metals such as As, Cd. The maximum Cd concentration in soil was 41.60 times more than the second level of Soil Environmental Quality Standard of China (SEQSC). Meanwhile, the carcinogenic risk of heavy metal polluted soil is much higher than the international acceptable limits (i.e. 1.0E-06) with maximum risk value at 148.7E-06. Source contribution analysis also disclosed that the carcinogenic risk in the tourism area is mainly attributed to As. It therefore can be concluded that As and Cd polluted soil in the tourism area of XX City needs to be recovered immediately in order to protect tourists health.

User Effects on Chamber Nitrous Oxide Emissions From Oxisol Soils in No-Tillage Maize Fertirrigated With Anaerobically Digested Swine Manure

Closed static chambers are frequently adopted for estimating gas fluxes across environmental interfaces. In this study we assessed the effects of three gas sampling rates and two methods of chamber placement in fertirrigated soils for estimating nitrous oxide (N2O) emissions, using chambers with similar design and on-site gas chromatography. The soils under analysis were fertirrigated with (liquid) digested swine manure at three different doses. The results indicate that N2O flux estimates are firmly determined by the chosen sampling rate, chamber placement, chamber design, and the emission magnitude itself. N2O fluxes were best estimated by faster sampling rates while gently placing the chamber at the soil surface due to conspicuous N2O emissions and relatively small chamber volume. A generalized chamber accumulation model developed by normalizing the dataset was used to illustrate effects on expected “low unforced-chamber”, “high unforced-chamber” and “high forced-chamber” fluxes. We concluded that it is possible to adopt simple design and low-disturbing chambers with sufficient volume, height, and surface area for determining gaseous emissions across soil-air interfaces. Nevertheless, critical on-site gas sampling rate adjustment (by gas chromatography or other as precise real-time measuring device) is critical to avoid estimation inaccuracies in emission estimates.

Multicommutated Stepwise Injection Analysis as new approach for simultaneous determination of nickel (II), copper (II) and zinc (II) in wet aerosols

Abstract A novel approach – Multicommutated Stepwise Injection Analysis (MCSWIA) – has been suggested for the simultaneous automation spectrophotometric determination of several components. Commutation to the MCSWIA manifold of two solenoid valves, two bidirectional peristaltic pumps and several mixing chambers provides the possibility to carry out several color-forming reactions. Thus, including the step of mixing of the sample with color-forming reagent solutions by gas bubbles in the mixing chambers allows to achieve the homogeneous solution and the completeness of color-forming reactions. The performance of the suggested approach is demonstrated by the MCSWIA spectrophotometric determination of nickel (II), copper (II) and zinc (II) in wet aerosols. The first stage of analysis assumes the on-site sampling of air aerosols by using of fiberglass columns. The second stage assumes spectrophotometric determination of analytes using MCSWIA. The selective color-forming reagents such as dimethylglyoxime, picramin–epsilon and 8-quinolinazo–epsilon were chosen for the spectrophotometric determination of nickel (II), copper (II) and zinc (II), respectively. The appropriate experimental conditions for air sampling and automated MCSWIA spectrophotometric procedure were investigated. The absorbance of colored complex at the wavelengths of 465 nm, 550 nm and 560 nm for nickel (II), copper (II) and zinc (II), respectively, obeys the Beer's law in the range of 1–40 μg/m 3 of nickel (II) and copper (II) and 10–100 μg/m 3 of zinc (II). The LODs, calculated from a blank test based on 3 , are 0.3 μg/m 3 for nickel (II) and copper (II) and 3 μg/m 3 for zinc (II).

Rapid On-Site Air Sampling with a Needle Extraction Device for Evaluating the Indoor Air Environment in School Facilities

A rapid on-site air sampling technique was developed with a miniaturized needle-type sample preparation device for a systematic evaluation of the indoor air environments in school facilities. With the in-needle extraction device packed with a polymer particle of divinylbenzene and activated carbon particles, various types of volatile organic compounds (VOCs) were successfully extracted. For evaluating the indoor air qualities in school facilities, air samples in renovated rooms using organic solvent as a thinner of the paint were analyzed along with measurements of several VOCs in indoor air samples taken in newly built primary schools mainly using low-VOCs materials. After periodical renovation/maintenance, the time-variation profile of typical VOCs found in the school facilities has also been monitored. From the results, it could be observed that the VOCs in most of the rooms in these primary schools were at a quite low level; however, a relatively higher concentration of VOCs was found in some specially designed rooms, such as music rooms. In addition, some non-regulated compounds, including benzyl alcohol and branched alkanes, were detected in these primary schools. The results showed a good applicability of the needle device to indoor air analysis in schools, suggesting a wide range of future employment of the needle device, especially for indoor air analysis in other types of facilities and rooms including hospitals and hotels.

Spatio-temporal variation of trace element contents in Rwanda necrosols

In this study, the spatio-temporal variation of selected trace elements in cemetery soils (necrosols) was investigated. Preliminary results revealed that onsite mean concentration for As, Ba, Cr, Cs, Ga, Ni, Rb, Sc, Th, V, Y, and Zr was generally higher than background offsite values. The trace metal contents of the cemetery soils also showed higher accumulation ratio for As, Cr, Ni, and Sc relative to world averages for soils (Clarke values). Similarly, it was observed that the cemetery soils showed significant enrichment with As and Cr in comparison with world averages for agricultural soils. The exchangeable sodium percentage showed that most of the onsite soil samples are sodic, which may have adverse effect on the growth and yield of crops grown in the study area. The study concludes that decomposition of human remains and grave contents play a significant role in elevating the total trace element contents in soils associated with cemeteries. For this reason, there is need for proactive measures to be taken with respect to the choice of raw materials used for the construction of coffins and funeral materials. There is need for local funeral industries particularly in developing countries and the government to begin to consider and adopt such green or environmental friendly burial options to prevent the potential environmental degradation of cemetery areas.