Identification of tolerance levels on the cold-water coral Desmophyllum pertusum (Lophelia pertusa) from realistic exposure conditions to suspended bentonite, barite and drill cutting particles.

Cold-water coral (CWC) reefs are numerous and widespread along the Norwegian continental shelf where oil and gas industry operate. Uncertainties exist regarding their impacts from operational discharges to drilling. Effect thresholds obtained from near-realistic exposure of suspended particle concentrations for use in coral risk modeling are particularly needed. Here, nubbins of Desmophyllum pertusum (Lophelia pertusa) were exposed shortly (5 days, 4h repeated pulses) to suspended particles (bentonite BE; barite BA, and drill cuttings DC) in the range of ~ 4 to ~ 60 mg.l-1 (actual concentration). Physiological responses (respiration rate, growth rate, mucus-related particulate organic carbon OC and particulate organic nitrogen ON) and polyp mortality were then measured 2 and 6 weeks post-exposure to assess long-term effects. Respiration and growth rates were not significantly different in any of the treatments tested compared to control. OC production was not affected in any treatment, but a significant increase of OC:ON in mucus produced by BE-exposed (23 and 48 mg.l-1) corals was revealed 2 weeks after exposure. Polyp mortality increased significantly at the two highest DC doses (19 and 49 mg.l-1) 2 and 6 weeks post-exposure but no significant difference was observed in any of the other treatments compared to the control. These findings are adding new knowledge on coral resilience to short realistic exposure of suspended drill particles and indicate overall a risk for long-term effects at a threshold of ~20 mg.l-1.

Supramolecular dynamic binary complexes with pH and salt-responsive properties for use in unconventional reservoirs.

Hydraulic fracturing of unconventional reservoirs has seen a boom in the last century, as a means to fulfill the growing energy demand in the world. The fracturing fluid used in the process plays a substantial role in determining the results. Hence, several research and development efforts have been geared towards developing more sustainable, efficient, and improved fracturing fluids. Herein, we present a dynamic binary complex (DBC) solution, with potential to be useful in the hydraulic fracturing domain. It has a supramolecular structure formed by the self-assembly of low molecular weight viscosifiers (LMWVs) oleic acid and diethylenetriamine into an elongated entangled network under alkaline conditions. With less than 2 wt% constituents dispersed in aqueous solution, a viscous gel that exhibits high viscosities even under shear was formed. Key features include responsiveness to pH and salinity, and a zero-shear viscosity that could be tuned by a factor of ~280 by changing the pH. Furthermore, its viscous properties were more pronounced in the presence of salt. Sand settling tests revealed its potential to hold up sand particles for extended periods of time. In conclusion, this DBC solution system has potential to be utilized as a smart salt-responsive, pH-switchable hydraulic fracturing fluid.

Preparation and properties of aflatoxins imprinted polymer grafted onto the surface of mesoporous silica SBA-15 functionalized with double bonds.

Mesoporous silica Santa Barbara-15 was functionalized by methacryloxypropyl trimethoxysilane. Taking this as the carrier material, a new mesoporous silica surface imprinted polymer was synthesized by using the C=C bond, functional monomer α-methacrylic acid, and crosslinker ethylene glycol dimethacrylate, which was used to extract aflatoxin from grain efficiently. It is different from the preparation of surface imprinted polymers which is physically wrapping carrier materials with polymer layers. The chemical grafting method makes the coating of the polymer layer more controllable. A new method for selective separation, enrichment, and determination of trace aflatoxin in grain was established by using the polymers as the filter of the solid-phase extraction column and high-performance liquid chromatography. The linear range of the method was 0.5-100 µg/kg, R2  = 0.9990-0.9993. The recovery of aflatoxin G2, G1, B2, and B1 was 98.9-119.7% and the relative standard deviation was 3.07-5.76%. By comparing the self-made column with the immunoaffinity column, it was found that the self-made column had better extraction performance for aflatoxins than the immunoaffinity column. It can be used for the analysis and detection of aflatoxins in cereal.

Single-crystal ordered macroporous metal-organic framework as support for molecularly imprinted polymers and their integration in membrane formant for the specific recognition of zearalenone.

Zearalenone is a fungal contaminant that is widely present in grains. Here, a novel molecularly imprinted membrane based on SOM-ZIF-8 was developed for the rapid and highly selective identification of zearalenone in grain samples. The molecularly imprinted membrane was prepared using polyvinylidene fluoride, cyclododecyl 2,4-dihydroxybenzoate as a template and SOM-ZIF-8 as a carrier. The factors influencing the extraction of zearalenone using this membrane, including the solution pH, extraction time, elution solvent, elution time, and elution volume, were studied in detail. The optimized conditions were 5 mL of sample solution at pH 6, extraction time of 45 min, 4 mL of acetonitrile:methanol = 9:1 as elution solvent, and elution time of 20 min. This method displayed a good linear range of 12-120 ng/g (R2  = 0.998) with the limits of detection and quantification of this method are 1.7 and 5.5 ng/g, respectively. In addition, the membrane was used to selectively identify zearalenone in grain samples with percent recoveries ranging from 87.9 to 101.0% and relative standard deviation of less than 6.6%. Overall, this study presents a simple and effective chromatographic pretreatment method for detecting zearalenone in food samples.

LSTM-based approach for predicting periodic motions of an impacting system via transient dynamics.

Dynamically impacting systems are characterised with inherent instability and complex non-linear phenomena which makes it practically difficult to predict the steady state response of the system at transient periods. This study investigates the ability of a data driven machine learning method using Long Short-Term Memory networks to learn the complex nonlinearity associated with co-existing impact responses from limited transient data. A one-degree-of-freedom impact oscillator has been used to represent the bit-rock interaction for percussive drilling. Simulated data results show velocity measurements to contribute most to predicting steady state responses from transient dynamics with most of the network models reaching an accuracy of over 95%. Limitations to practically measurable variables in dynamic systems warranted the development of a feature based network model for impact motion classification. Experimental data from a two-degrees-of-freedom impacting system representing percussive bit penetration has been used to demonstrate the effectiveness of this method. The study thus provides a precise and less computational means of detecting and avoiding underperforming impact modes in percussive drilling.

Subcritical Water Extraction of Valuable Metals from Spent Lithium-Ion Batteries.

The leaching of valuable metals (Co, Li, and Mn) from spent lithium-ion batteries (LIBs) was studied using subcritical water extraction (SWE). Two types of leaching agents, hydrochloric acid (HCl) and ascorbic acid, were used, and the effects of acid concentration and temperature were investigated. Leaching efficiency of metals increased with increasing acid concentration and temperature. Ascorbic acid performed better than HCl, which was attributed to ascorbic acid's dual functions as an acidic leaching agent and a reducing agent that facilitates leaching reactions, while HCl mainly provides acidity. The chemical analysis of leaching residue by X-ray photoelectron spectroscopy (XPS) revealed that Co(III) oxide could be totally leached out in ascorbic acid but not in HCl. More than 95% of Co, Li, and Mn were leached out from spent LIBs' cathode powder by SWE using 0.2 M of ascorbic acid within 30 min at 100 °C, initial pressure of 10 bar, and solid-to-liquid ratio of 10 g/L. The application of SWE with a mild concentration of ascorbic acid at 100 °C could be an alternative process for the recovery of valuable metal in spent LIBs. The process has the advantages of rapid reaction rate and energy efficiency that may benefit development of a circular economy.

The Role of Extracting Solvents in the Recovery of Polyphenols from Green Tea and Its Antiradical Activity Supported by Principal Component Analysis.

Green tea contains a variety of biologically active constituents that are widely used in the pharmaceutical and food industries. Among them, simple catechins constitute a major group of compounds that is primarily responsible for the high biologic activity of green tea extracts. Therefore, the application of optimized extraction conditions may result in obtaining high value extracts. The main purpose of the study was to compare the content of polyphenols, mainly catechins, and the antioxidant activity of green tea extracts obtained by three different extraction methods: simple maceration, ultrasound extraction and accelerated solvent extraction using six various solvent systems. The quality of the extracts was evaluated by LC-ESI-Q-TOF-MS methodologies and spectrophotometric determinations. The obtained results revealed that catechins' extraction efficiency was identical for the three techniques studied. However, larger quantitative differences among the samples were observed when using different solvents. The total content of major catechins and gallic acid was within a very wide range of 10.2-842 mg/L. Ethyl acetate was by far the least effective extractant, regardless of the extraction technique used. After all, the solvent system composed of ethanol:water (1:1 v/v) was proven to be the best to recover catechins and to deliver extracts with the highest antiradical activity.

Developmental exposure to chemicals associated with unconventional oil and gas extraction alters immune homeostasis and viral immunity of the amphibian Xenopus.

Although aquatic vertebrates and humans are increasingly exposed to water pollutants associated with unconventional oil and gas extraction (UOG), the long-term effects of these pollutants on immunity remains unclear. We have established the amphibian Xenopus laevis and the ranavirus Frog Virus 3 (FV3) as a reliable and sensitive model for evaluating the effects of waterborne pollutants. X. laevis tadpoles were exposed to a mixture of equimass amount of UOG chemicals with endocrine disrupting activity (0.1 and 1.0 µg/L) for 3 weeks, and then long-term effects on immune function at steady state and following viral (FV3) infection was assessed after metamorphosis. Notably, developmental exposure to the mixture of UOG chemicals at the tadpole stage affected metamorphic development and fitness by significantly decreasing body mass after metamorphosis completion. Furthermore, developmental exposure to UOGs resulted in perturbation of immune homeostasis in adult frogs, as indicated by significantly decreased number of splenic innate leukocytes, B and T lymphocytes; and a weakened antiviral immune response leading to increased viral load during infection by the ranavirus FV3. These findings suggest that mixture of UOG-associated waterborne endocrine disruptors at low but environmentally-relevant levels have the potential to induce long-lasting alterations of immune function and antiviral immunity in aquatic vertebrates and ultimately human populations.

Dynamics of metals in backfill of a phosphate mine of guiyang, China using a three-step sequential extraction technique.

Phosphate rock in Guiyang (Southwest of China) is used for the phosphate production, and hence generating a by-product phosphogypsum (PG). From 2007, part of the PG was used as main raw material for cemented backfill. The main objective of this paper is to investigate the geochemical evolution of metals before and after the PG inclusion into the backfill matrix. A sequential extraction procedure was selected to determine the chemical speciation of metals in phosphate rock, PG, binder and field backfill samples. Dynamics of metals going from phosphate rock and PG to backfill have been evaluated. The results showed that almost all the metals in the PG and binder had been effectively transferred to the backfill. Furthermore, compared to metals taken out along with phosphate rock exploitation, PG-based cemented backfill might bring some metals back but with only little metals in mobile fraction. Additionally, in order to determine the long-term behavior of metals in PG-based cemented backfill, the field samples which were backfilled from 2007 to 2016 were collected and analyzed. The results showed that total amounts of metals in backfill were all within similar range, indicating that the cemented PG backfill could be an effective method to solidify/stabilize metals in PG. Nevertheless, Due to the high water-soluble fractions detected, the concentrations of As, Mn and Zn should be continuously monitored.

Contamination Control for Scientific Drilling Operations.

Drilling is an integral part of subsurface exploration. Because almost all drilling operations require the use of a drill fluid, contamination by infiltration of drill fluid into the recovered core material cannot be avoided. Because it is impossible to maintain sterile conditions during drilling the drill fluid will contain surface microbes and other contaminants. As contamination cannot be avoided, it has to be tracked to identify those parts of the drill core that were not infiltrated by the drill fluid. This is done by the addition of tracer compounds. A great variety of tracers is available, and the choice depends on many factors. This review will first explain the basic principles of drilling before presenting the most common tracers and discussing their strengths and weaknesses. The final part of this review presents a number of key questions that have to be addressed in order to find the right tracer for a particular drilling operation.

Challenges for critical raw material recovery from WEEE - The case study of gallium.

Gallium and gallium compounds are more frequently used in future oriented technologies such as photovoltaics, light diodes and semiconductor technology. In the long term the supply risk is estimated to be critical. Germany is one of the major primary gallium producer, recycler of gallium from new scrap and GaAs wafer producer. Therefore, new concepts for a resource saving handling of gallium and appropriate recycling strategies have to be designed. This study focus on options for a possible recycling of gallium from waste electric and electronic equipment. To identify first starting points, a substance flow analysis was carried out for gallium applied in integrated circuits applied on printed circuit boards and for LEDs used for background lighting in Germany in 2012. Moreover, integrated circuits (radio amplifier chips) were investigated in detail to deduce first approaches for a recycling of such components. An analysis of recycling barriers was carried out in order to investigate general opportunities and risks for the recycling of gallium from chips and LEDs. Results show, that significant gallium losses arose in primary production and in waste management. 93±11%, equivalent to 43,000±4700kg of the total gallium potential was lost over the whole primary production process until applied in electronic goods. The largest share of 14,000±2300kggallium was lost in the production process of primary raw materials. The subsequent refining process was related to additional 6900±3700kg and the chip and wafer production to 21,700±3200kg lost gallium. Results for the waste management revealed only low collection rates for related end-of-life devices. Not collected devices held 300 ± 200 kg gallium. Due to the fact, that current waste management processes do not recover gallium, further 80 ± 10 kg gallium were lost. A thermal pre-treatment of the chips, followed by a manual separation allowed an isolation of gallium rich fractions, with gallium mass fractions up to 35%. Here, gallium loads per chip were between 0.9 and 1.3mg. Copper, gold and arsenic were determined as well. Further treatment options for this gallium rich fraction were assessed. The conventional pyrometallurgical copper route might be feasible. A recovery of gold and gallium in combination with copper is possible due to a compatibility with this base-metal. But, a selective separation prior to this process is necessary. Diluted with other materials, the gallium content would be too low. The recycling of gallium from chips applied on printed circuit boards and LEDs used for background lighting is technically complex. Recycling barriers exist over the whole recycling chain. A forthcoming commercial implementation is not expected in nearer future. This applies in particular for chips carrying gallium.

Oil recovery from petroleum sludge through ultrasonic assisted solvent extraction.

The effect of ultrasonic assisted extraction (UAE) process on oil recovery from refinery oily sludge was examined in this study. Two types of UAE treatment including UAE probe (UAEP) system and UAE bath (UAEB) system were investigated. Their oil recovery efficiencies were compared to that of mechanical shaking extraction (MSE). Three solvents including cyclohexane (CHX), ethyl acetate (EA), and methyl ethyl ketone (MEK) were examined as the extraction solvents. The influence of experimental factors on oil and solvent recovery was investigated using an orthogonal experimental design. Results indicated that solvent type, solvent-to-sludge (S/S) ratio, and treatment duration could have significant effects on oil recovery in UAE treatment. Under the optimum conditions, UAEP treatment can obtain an oil recovery of 68.8% within 20 s, which was higher than that (i.e., 62.0%) by MSE treatment after 60 min' extraction. UAEB treatment can also obtain a promising oil recovery within shorter extraction duration (i.e., 15 min) than MSE. UAE was thus illustrated as an effective and improved approach for oily sludge recycling.

Effects of thermal treatments on the characterisation and utilisation of red mud with sawdust additive.

Extremely large amounts of red mud (bauxite residue) are generated globally every year from alumina refining industries, which are being disposed of on engineered landfills. The objective of this study is to investigate the effects of thermal treatments on red mud for development of utilisation strategies. Thermal treatments of red mud samples and their characterisations were investigated under inert (N2) and oxidative (air) conditions with and without sawdust addition at 200-600°C. After calcination, the resulting samples were analysed using thermogravimetric-infrared spectroscopy (TG-IR) for functional group transformations, thermogravimetric analysis (TGA) for thermal loss profiles and X-ray diffraction (XRD) for mineral transformations. The characterisation results showed that in N2 environment, boehmite in red mud was transferred to transition alumina at around 400°C while losing water from structural components. The addition of sawdust for incubation and calcination of red mud in air increased the surface area, whereas that in nitrogen atmosphere lead to reduction of hematite to magnetite at around 500°C. The incorporated carbon materials played a major role in increasing the surface area especially for pore size less than 2.5 nm. This treated red mud with altered mineral composition and improved properties for binding contaminants can be used for environmental remediation and in the process of metal recovery such as iron.

[Heavy metals and hydrocarbons content in soils of settlements of the Yamal-Nenets autonomous region].

In August 2015 there were executed investigations on the study of the soils diversity of the Yamal-Nenets Autonomous Okrug. One of the directions of this work got be the study of urban soils of settlements of the Yamal-Nenents Autonomous Okrug. The sectors for the observation were settlement of Harsaim, village Aksarka, city of Salekhard, settlement Harp and city of Labytnangi. About 20 soil samples were collected during the field work. Samples were collected from a depth of 0-5 cm and 5-20 cm. Heavy metals (HM) were detected with the use of X-ray fluorescent analyzer "Spectroscan-MAX". The HM content values were compared with the corresponding Approxible Permissible Concentrations and Maximum Allowable Concentrations (MAC) adopted in Russia. Hydrocarbons content was determined by gravimetric method. Values of the hydrocarbons content in studied soils were compared with the existing regulations of the Russian Federation. The levels of soil contamination by hydrocarbons were determined. The study of soil samples from different settlements allowed to reveal characteristic features of soil contamination of separate settlements by HM and hydrocarbons and to compare them against each other. The vast majority of samples are characterized by arsenic exceedance of MAC, which should indicate to a high regional background of this element. For a more adequate assessment of the Zc meaning as the value of the total pollution index of soils there were used not only arithmetical average values of the coefficients of the chemical composition concentration (Kc), but also their average geometric values. According to levels of total soil contamination most of soil samples are characterized as non-hazardous (Zc<16). Calculation of soil pollution index showed that the most of soil samples have values less than 1. It characterizes soils as unpolluted. Statistical processing of obtained data in the media of the analytical software interface STATISTICA 10 showed a statistically significant difference in the content ofHM and hydrocarbons for the layer of 0-20 cm of the soils for three elements (Cu, Zn, Ni).

[Choice of informative laboratory biomarkers for the early identification of changes in neurohumoral regulation and carbohydrate exchange in workers of the mining and mechanical engineering industry].

The diagnostic significance of hormones and integral indices of pituitary-adrenal, pituitary-thyroid and pituitary-gonadal system and carbohydrate metabolism (ACTH (corticotropin), aldosterone, cortisol, TSH (thyroid-stimulating hormone), free triiodothyronine (fT3), free thyroxine (fT4), luteinizing hormone (LH), follicle-stimulating hormone (FSH), total and free testosterone, insulin, integral pituitary-adrenal index (IPAI), the pituitary-thyroid index (PTI), indices of carbohydrate metabolism (Caro and HOMA-IR) was studied for the early diagnostics of disorders of neurohumoral regulation in workers of mining and mechanical engineering industries. The most informative indices, permitting to identify disorders of carbohydrate metabolism are established to be indices of insulin resistance (index Caro and index NOMA-IR) and the determination of insulin in serum. For the identification of changes in pituitary adrenal, pituitary-thyroid and pituitary-gonadal system in patients with vibration disease, sensory-neural hearing loss, comorbidity indexes IGNI, ITI, concentrations of LH and total testosterone are of the most diagnostically significance.

Estimation of methane emission from California natural gas industry.

UNLABELLED: Energy generation and consumption are the main contributors to greenhouse gases emissions in California. Natural gas is one of the primary sources of energy in California. A study was recently conducted to develop current, reliable, and California-specific source emission factors (EFs) that could be used to establish a more accurate methane emission inventory for the California natural gas industry. Twenty-five natural gas facilities were surveyed; the surveyed equipment included wellheads (172), separators (131), dehydrators (17), piping segments (145), compressors (66), pneumatic devices (374), metering and regulating (M&R) stations (19), hatches (34), pumps (2), and customer meters (12). In total, 92,157 components were screened, including flanges (10,101), manual valves (10,765), open-ended lines (384), pressure relief valves (358), regulators (930), seals (146), threaded connections (57,061), and welded connections (12,274). Screening values (SVs) were measured using portable monitoring instruments, and Hi-Flow samplers were then used to quantify fugitive emission rates. For a given SV range, the measured leak rates might span several orders of magnitude. The correlation equations between the leak rates and SVs were derived. All the component leakage rate histograms appeared to have the same trend, with the majority of leakage rates<0.02 cubic feet per minute (cfm). Using the cumulative distribution function, the geometric mean was found to be a better indicator than the arithmetic mean, as the mean for each group of leakage rates found. For most component types, the pegged EFs for SVs of ≥10,000 ppmV and of ≥50,000 ppmV are relatively similar. The component-level average EFs derived in this study are often smaller than the corresponding ones in the 1996 U.S. Environmental Protection Agency/Gas Research Institute (EPA/GRI) study. IMPLICATIONS: Twenty-five natural gas facilities in California were surveyed to develop current, reliable, and California-specific source emission factors (EFs) for the natural gas industry. Screening values were measured by using portable monitoring instruments, and Hi-Flow samplers were then used to quantify fugitive emission rates. The component-level average EFs derived in this study are often smaller than the corresponding ones in the 1996 EPA/GRI study. The smaller EF values from this study might be partially attributable to the employment of the leak detection and repair program by most, if not all, of the facilities surveyed.

Evaluating a groundwater supply contamination incident attributed to Marcellus Shale gas development.

High-volume hydraulic fracturing (HVHF) has revolutionized the oil and gas industry worldwide but has been accompanied by highly controversial incidents of reported water contamination. For example, groundwater contamination by stray natural gas and spillage of brine and other gas drilling-related fluids is known to occur. However, contamination of shallow potable aquifers by HVHF at depth has never been fully documented. We investigated a case where Marcellus Shale gas wells in Pennsylvania caused inundation of natural gas and foam in initially potable groundwater used by several households. With comprehensive 2D gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS), an unresolved complex mixture of organic compounds was identified in the aquifer. Similar signatures were also observed in flowback from Marcellus Shale gas wells. A compound identified in flowback, 2-n-Butoxyethanol, was also positively identified in one of the foaming drinking water wells at nanogram-per-liter concentrations. The most likely explanation of the incident is that stray natural gas and drilling or HF compounds were driven ∼ 1-3 km along shallow to intermediate depth fractures to the aquifer used as a potable water source. Part of the problem may have been wastewaters from a pit leak reported at the nearest gas well pad-the only nearby pad where wells were hydraulically fractured before the contamination incident. If samples of drilling, pit, and HVHF fluids had been available, GCxGC-TOFMS might have fingerprinted the contamination source. Such evaluations would contribute significantly to better management practices as the shale gas industry expands worldwide.

Air contaminants associated with potential respiratory effects from unconventional resource development activities.

Unconventional natural gas development uses horizontal drilling in conjunction with hydraulic fracturing to gain access to natural gas deposits which may be tightly held in shale deposits and unavailable to conventional vertical drilling operations. The intensive work required to extract this source of energy results in higher than usual numbers of vehicles involved, potential release of emissions from those vehicles in congested zones surrounding the drill site, and release of other contaminants from materials drawn back out of the borehole after fracturing of the shale. Typical contaminants would be diesel exhaust particulate and gases, volatile organic compounds and other hydrocarbons both from diesels and the drilling process, crystalline silica, used as part of the hydraulic fracturing process in kiloton quantities, and methane escaping from the borehole and piping. A rise in respiratory disease with proximity to the process has been reported in nearby communities and both silica and diesel exposures at the worksite are recognized respiratory hazards. Because of the relatively short time this process has been used to the extent it is currently being used, it is not possible to draw detailed conclusions about the respiratory hazards that may be posed. However, based on the traffic volume associated with each drill site and the number of drill sites in any locale, it is possible at least to compare the effects to that of large traffic volume highways which are known to produce some respiratory effects in surrounding areas.

[Chemical hazards arising from shale gas extraction]. / Zagrozenia chemiczne zwiazane z eksploatacja gazu lupkowego.

The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extreiely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest, concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction.