To estimate the variability of pesticide residue levels present in cauliflower units, a total of 142 samples were collected from a field trial of a cooperative farmer, and 120 samples were collected from different market places in Thessaloniki, Greece. The collected samples were extracted using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction technique, and the residues were determined by liquid chromatography–tandem mass spectrometry. The developed method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD), and limit of quantification (LOQ). The average recoveries for all the analytes, derived from the data of control samples fortified at 0.01, 0.05, 0.1, and 0.2 mg/kg, ranged from 74 to 110% with a relative standard deviation of ≤8%. The correlation coefficient (R2) was ≥0.997 for all the analytes using matrix-matched calibration standards. The LOD values ranged from 0.001 to 0.003 mg/kg, and the LOQ was determined at 0.01 mg/kg for all the sought analytes. The matrix effect was found to be at a considerable level, especially for cypermethrin and deltamethrin, amounting to +90% and +145%, respectively. For the field samples, the unit-to-unit variability factors (VFs) calculated for cypermethrin and deltamethrin were 2.38 and 2.32, respectively, while the average VF for the market basket samples was 5.11. In the market basket samples, residues of cypermethrin, deltamethrin, chlorpyrifos, and indoxacarb were found at levels ≥LOQ and their respective VFs were 7.12, 5.67, 5.28, and 2.40. 相似文献
This paper reports on recycling of industrial wastes (three pharmaceutical industrial sludges) into environmental friendly value-added materials. Stabilization/Solidification (S/S or bricks) process was applied to make a safer way for the utilization of pharmaceutical waste. The additives in this study include binders (cement, lime and bentonite) and strengthening material (pulverized fuel ash (PFA), silica fume and quarry dust) was used at different compositions. Bricks were cured for 28 days, and the following analysis-like compressive strength, leachability of heavy metals, mineralogical phase identity by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermal behaviour by thermogravimetric-differential thermal analysis (TG-DTA) had done. All the bricks were observed to achieve the standard compressive strength as required for construction according to BIS standards. Metal concentration in the leachate has reached the dischargeable limits according to Brazilian standards. Results of this study demonstrate that production of bricks is a promising and achievable productive use of pharmaceutical sludge. 相似文献
Various human activities like mining and extraction of mineral oils have been used for the modernization of society and well-beings. However, the by-products such as petrochemical wastes generated from such industries are carcinogenic and toxic, which had increased environmental pollution and risks to human health several folds. Various methods such as physical, chemical and biological methods have been used to degrade these pollutants from wastewater. Advance oxidation processes (AOPs) are evolving techniques for efficient sequestration of chemically stable and less biodegradable organic pollutants. In the present review, photocatalytic degradation of petrochemical wastes containing monoaromatic and poly-aromatic hydrocarbons has been studied using various heterogeneous photocatalysts (such as TiO2, ZnO and CdS. The present article seeks to offer a scientific and technical overview of the current trend in the use of the photocatalyst for remediation and degradation of petrochemical waste depending upon the recent advances in photodegradation of petrochemical research using bibliometric analysis. We further outlined the effect of various heterogeneous catalysts and their ecotoxicity, various degradation pathways of petrochemical wastes, the key regulatory parameters and the reactors used. A critical analysis of the available literature revealed that TiO2 is widely reported in the degradation processes along with other semiconductors/nanomaterials in visible and UV light irradiation. Further, various degradation studies have been carried out at laboratory scale in the presence of UV light. However, further elaborative research is needed for successful application of the laboratory scale techniques to pilot-scale operation and to develop environmental friendly catalysts which support the sustainable treatment technology with the “zero concept” of industrial wastewater. Nevertheless, there is a need to develop more effective methods which consume less energy and are more efficient in pilot scale for the demineralization of pollutant. 相似文献
A multi-disciplinary approach was used to evaluate the health of yellow perch (Perca flavescens) in the St. Lawrence River (Quebec, Canada), which is experiencing a severe population decline in the downstream portion of the river. Physiological parameters, liver alterations, trace metal concentrations, parasite prevalence and abundance, stable isotope composition, and the presence/absence of the viral hemorragic septicemia virus (VHSV) were evaluated in perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island, and Lake St. Pierre (north and south). Trace metal concentrations in surface water were higher in Lake St. Louis and downstream of a major urban wastewater treatment plant discharge, indicating that this effluent was a significant source of Cu, As, Ag, Zn, and Cd. Levels of Pb in surface water exceeded thresholds for the protection of aquatic life in Lake St. Louis and were negatively correlated with body condition index in this lake. In Lake St. Pierre, Cu, Ag, and Cd bioaccumulated significantly in perch liver and lower body condition index and greater liver damage were observed compared to upstream sites. Parasite analyses indicated a higher abundance of metacercariae of the trematodes Apophallus brevis and Diplostomum spp. in Lake St. Louis, and VHSV was not detected in the liver of yellow perch for all studied sites. Overall, results suggested that the global health of yellow perch from Lake St. Pierre is lower compared to upstream studied sites, which could contribute to the documented population collapse at this site. 相似文献
In early April 2011, radiostrontium was accidentally released from the Fukushima Daiichi Nuclear Power Plant to the Pacific coast of eastern Japan. We developed a simple procedure to analyze radiostrontium levels in marine mussels (Septifer virgatus) and seawater using crown ether (Sr Resin; Eichrom). Then, we used our method to describe the spatial and temporal distribution of radiostrontium in mussels and seawater on the Pacific coast of eastern Japan from 2011 to 2013 and for 2015. Activity of 90Sr in mussels and seawater decreased with distance from the Fukushima Daiichi Nuclear Power Plant and between 2011 and 2013 tended to be higher in areas south of the Fukushima Daiichi Nuclear Power Plant than to the north of it. Activity in mussels and seawater also tended to decrease from 2011 to 2013 and by 2015 had reached levels experienced prior to the Fukushima accident. Our results suggest that radiostrontium discharged from the Fukushima Daiichi Nuclear Power Plant was dispersed by coastal currents in a southerly direction along the Pacific coast of eastern Japan from 2011 to 2013, following which its activity decreased to background levels by 2015. 相似文献
Laser-induced breakdown spectroscopy (LIBS) is a laser-based optical technique particularly suited for in situ surface analysis. A portable LIBS instrument was tested to detect surface chemical contamination by chemical warfare agents (CWAs). Test of detection of surface contamination was carried out in a toxlab facility with four CWAs, sarin (GB), lewisite (L1), mustard gas (HD), and VX, which were deposited on different substrates, wood, concrete, military green paint, gloves, and ceramic. The CWAs were detected by means of the detection of atomic markers (As, P, F, Cl, and S). The LIBS instrument can give a direct response in terms of detection thanks to an integrated interface for non-expert users or so called end-users. We have evaluated the capability of automatic detection of the selected CWAs. The sensitivity of our portable LIBS instrument was confirmed for the detection of a CWA at surface concentrations above 15 μg/cm2. The simultaneous detection of two markers may lead to a decrease of the number of false positive. 相似文献
Silicon-based fertilizers and soil amendments can have direct and indirect positive influences on cultivated plants. The solid forms of Si-based substances, the most widespread in use, are efficient only at high application rates due to their low level of solubility. Several types of Si-based substances such as fumed silica, slags from the iron and steel industry, modified slags, and a Si-rich product were tested using barley and pea as silicon accumulative and non-accumulative plants, respectively, at two application rates. The plants were grown under toxic concentrations of heavy metals in a greenhouse. Si-rich materials high in water-soluble Si had a positive effect at both the low and high application rates, and for both plant species. This type of substance can be regarded as Si fertilizer, demonstrating greater efficiency at a low application rate and lessened efficiency at a high application rate for protection of the cultivated plants against accumulation of the heavy metals.
The measurement of hydrochloric acid (HCl) on a continuous basis in coal-fired plants is expected to become more important if HCl standards become implemented as part of the Federal Mercury and Air Toxics Standards (MATS) standards that are under consideration. For this study, the operational performance of three methods/instruments, including tunable diode laser absorption spectroscopy (TDLAS), cavity ring down spectroscopy (CRDS), and Fourier transform infrared (FTIR) spectroscopy, were evaluated over a range of real-world operating environments. Evaluations were done over an HCl concentration range of 0–25 ppmv and temperatures of 25, 100, and 185 °C. The average differences with respect to temperature were 3.0% for the TDL for values over 2.0 ppmv and 6.9% of all concentrations, 3.3% for the CRDS, and 4.5% for the FTIR. Interference tests for H2O, SO2, and CO, CO2, and NO for a range of concentrations typical of flue gases from coal-fired power plants did not show any strong interferences. The possible exception was an interference from H2O with the FTIR. The instrument average precision over the entire range was 4.4% for the TDL with better precision seen for concentrations levels of 2.0 ppmv and above, 2.5% for the CRDS, and 3.5% for the FTIR. The minimum detection limits were all on the order of 0.25 ppmv, or less, utilizing the TDL values with a 5-m path. Zero drift was found to be 1.48% for the TDL, 0.88% for the CRDS, and 1.28% for the FTIR.
Implications: This study provides an evaluation of the operational performance of three methods/instruments, including TDL absorption spectroscopy (TDLAS), cavity ring down spectroscopy (CRDS), and FTIR spectroscopy, for the measurement of hydrochloric acid (HCl) over a range of real-world operating environments. The results showed good instrument accuracy as a function of temperature and no strong interferences for flue gases typical to coal-fired power plants. The results show that these instruments would be viable for the measurement of HCl in coal-fired plants if HCl standards become implemented as part of the Federal Mercury and Air Toxics Standards (MATS) standards that are under consideration. 相似文献