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Abstract Mobile in situ concentration and meteorology data were collected for the Chino Dairy Complex in the Los Angeles Basin by AMOG (AutoMObile trace Gas) Surveyor on 25 June 2015 to characterize husbandry emissions in the near and far field in convoy mode with MISTIR (Mobile Infrared Sensor for Tactical Incident Response), a mobile upwards-looking, column remote sensing spectrometer. MISTIR reference flux validated AMOG plume inversions at different information levels including multiple gases, GoogleEarth imagery, and airborne trace gas remote sensing data. Long-term (9-yr.) Infrared Atmospheric Sounding Interferometer satellite data provided spatial and trace gas temporal context. For the Chino dairies, MISTIR-AMOG ammonia (NH 3) agreement was within 5% (15.7 versus 14.9 Gg yr−1, respectively) using all information. Methane (CH 4) emissions were 30 Gg yr−1 for a 45,200 herd size, indicating that Chino emission factors are greater than previously reported. Single dairy inversions were much less successful. AMOG-MISTIR agreement was 57% due to wind heterogeneity from downwind structures in these near-field measurements and emissions unsteadiness. AMOG CH 4 , NH 3 , and CO 2 emissions were 91, 209, and 8200 Mg yr−1, implying 2480, 1870, and 1720 head using published emission factors. Plumes fingerprinting identified likely sources including manure storage, cowsheds, and a structure with likely natural gas combustion. NH 3 downwind of Chino showed a seasonal variation of a factor of ten, three times larger than literature suggests. Chino husbandry practices and trends in herd size and production were reviewed and unlikely to add seasonality. Higher emission seasonality was proposed as legacy soil emissions, the results of a century of husbandry, supported by airborne remote sensing data showing widespread emissions from neighborhoods that were dairies 15 years prior, and AMOG and MISTIR observations. Seasonal variations provide insights into the implications of global climate change and must be considered when comparing surveys from different seasons. Graphical abstract Eight-plume informed (8I) Gaussian inversion model for I-15 downwind (north to south) transect with respect to arbitrary lateral distance (y) for A) ammonia anomaly (NH 3 ') and winds (u) versus relative northing (x). Plume peaks labeled. Arrows show transect features modeled that indicated the six-plume uninformed model (not shown). B) In situ NH 3 and u data superimposed on Mako column ammonia (XNH 3) data for 25 Jul. 2014, 1820-1846 UTC (1020-1046 LT), and the 8I model-projected plumes' origins in the Google Earth environment. Selected transect plume features labeled. White arrows bracket the transect line onto which transect data are projected. Data key on figure. Shown in the Google Earth environment. Image 1 Highlights • Herd size from three different trace gases converge to ±20% of the average value. • Seasonality is observed in NH 3 and CH 4 satellite data, affecting annualized rates. • Seasonality must be considered when comparing campaigns in different seasons. • NH 3 seasonality was 900%; proposed legacy soil emissions, observed in airborne data. • Midsummer Chino dairy emissions were 15.7 Gg NH 3 yr−1 and 30 Gg CH 4 yr−1. Where sufficient information from multiple gases and number of likely sources, high emissions accuracy can be achieved for in situ data plume inversion. [ABSTRACT FROM AUTHOR]

The production of oil from oil sands in northern Alberta has led to the generation of large volumes of oil sands process-affected water (OSPW) that was reported to be toxic to aquatic and other living organisms. The toxicity of OSPW has been attributed to the complex nature of OSPW matrix including the inorganic and organic compounds primarily naphthenic acids (NAs: C n H 2n+Z O x ). In the present study, granular activated carbon (GAC) adsorption was investigated for its potential use to treat raw and ozonated OSPW. The results indicated that NA species removal increased with carbon number (n) for a fixed Z number; however, the NA species removal decreased with Z number for a fixed carbon number. The maximum adsorption capacities obtained from Langmuir adsorption isotherm based on acid-extractable fraction (AEF) and NAs were 98.5 mg and 60.9 mg AEF/g GAC and 60 mg and 37 mg NA/g GAC for raw and ozonated OSPW, respectively. It was found that the Freundlich isotherm model best fits the AEF and NA equilibrium data (r 2  ≥ 0.88). The adsorption kinetics showed that the pseudo-second order and intraparticle diffusion models were both appropriate in modeling the adsorption kinetics of AEF and NAs to GAC (r 2  ≥ 0.97). Although pore diffusion was the rate limiting step, film diffusion was still significant for assessing the rate of diffusion of NAs. This study could be helpful to model, design and optimize the adsorption treatment technologies of OSPW and to assess the performance of other adsorbents. [ABSTRACT FROM AUTHOR]

This paper describes the sensor technology, measurement methodology and data analysis algorithms that are used to characterize gaseous emissions observed with a large-area coverage longwave-infrared (LWIR) hyperspectral imaging (HSI) sensor. In so doing the demonstrated capability is expanded well beyond the small number of gas species that have typically been reported and also sets these observations within a definitive, comprehensive framework that documents in detail the procedures used for detection, identification, and quantification of atmospheric trace gases using LWIR HSI systems, along with the methodology for determining their respective detection limits. Examples are provided for a 530 km 2 region of the Los Angeles Basin collected on July 22, 2014. [ABSTRACT FROM AUTHOR]

Humans are exposed to arsenic (As) from various sources such as food, drinking water, and air, thus, treatment of water matrices contaminated with As is a worldwide challenge. In this work, H 3 PO 4 and FeCl 3 treated canola straw biochar (CSB) was assessed for its adsorption efficiency for arsenite, As(III), and arsenate, As(V), in water. The main factors in determination of an optimal CSB (OCSB) included microwave (MW) power for the creation of the biochar and FeCl 3 modification. For both As(III) and As(V), the highest performing biochar was found to be at the highest MW power (1000 W) and lowest FeCl 3 concentration (0.1 M). It was found that biochar surface area was enhanced by biomass activation using FeCl 3 and no crystalline phases of FeCl 3 were identified, potentially a consequence of the low iron concentrations considered. Modification parameters were studied and showed that pH 7 was more favorable for As(V) adsorption, while pH 10 favored As(III) adsorption. Additionally, isotherm and kinetic analysis indicated that a physical adsorption mechanism took place for As(III) and As(V) which may have resulted from surface complexation. Life cycle assessment (LCA) results showed that OCSB production is environmentally friendly, generating − 0.298 kg CO 2 eq/kg of biochar. For an economic perspective, a life cycle cost analysis (LCCA) of OCSB found a cost of $5.14/kg (USD) of biochar that is mainly impacted by materials. Overall, OCSB shows potential for As adsorption and environmental evaluation shows promising results for consideration of this biochar as an adsorbent. [Display omitted] • Arsenic (As) contaminates waters worldwide and can be treated by adsorption. • Modified canola straw biochar (CSB) is an effective As adsorbent. • Optimal microwave power and iron chloride doses can improve CSB adsorption. • Life cycle assessment found − 0.298 kg CO 2 eq/kg of biochar. • Life cycle cost analysis found a cost of $5.14 kg/biochar (USD). [ABSTRACT FROM AUTHOR]

Methane (CH 4 ) and ammonia (NH 3 ) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal InfraRed (TIR) that can be studied by remote sensing, with NH 3 allowing discrimination of husbandry from other CH 4 sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH 4 , carbon dioxide (CO 2 ) and NH 3 data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20 km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1 × 10 5 kg CH 4 , 2.2 × 10 5 kg NH 3 , and 2.3 × 10 7 kg CO 2 , suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42 Gg CH 4 and 8.4 Gg NH 3 implying ∼200k cows, ∼30% more than Peischl et al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH 3 occurs within the confines of the Los Angeles Basin on a four to six h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others. [ABSTRACT FROM AUTHOR]

This review covers the characterization and distribution of metals and nonmetals in the Alberta oil sands region (AOSR) of Canada. The development of the oil sands industry has resulted in the release of organic, metal and nonmetal contaminants via air and water to the AOSR. For air, studies have found that atmospheric deposition of metals in the AOSR decreased exponentially with distance from the industrial emission sources. For water, toxic metal concentrations often exceeded safe levels leading to the potential for negative impacts to the receiving aquatic environments. Interestingly, although atmospheric deposition, surface waters, fish tissues, and aquatic bird eggs exhibited increasing level of metals in the AOSR, reported results from river sediments showed no increases over time. This could be attributed to physical and/or chemical dynamics of the river system to transport metals to downstream. The monitoring of the airborne emissions of relevant nonmetals (nitrogen and sulphur species) was also considered over the AOSR. These species were found to be increasing along with the oil sands developments with the resultant depositions contributing to nitrogen and sulphur accumulations resulting in ecosystem acidification and eutrophication impacts. In addition to direct monitoring of metals/nonmetals, tracing of air emissions using isotopes was also discussed. Further investigation and characterization of metals/nonmetals emissions in the AOSR are needed to determine their impacts to the ecosystem and to assess the need for further treatment measures to limit their continued output into the receiving environments. [ABSTRACT FROM AUTHOR]

Naphthenic acids (NAs) from oil sand process-affected water (OSPW) were liquid–liquid extracted using six organic solvents (n-pentane, n-hexane, cyclohexane, dichloromethane, ethyl ether, and ethyl acetate) at three pHs (2.0, 8.5, and 12.0). The NAs exist in ionic (ions) and non-ionic (molecules) forms in the water phase depending on their dissociation constants and the solution pH. Results showed the extractability of NA molecules depends on the solvent polarity and the extractability of NA ions on the water solubility in solvent. The organic solvent type and solution pH were found to not only impact the extracted amounts of each NA species, but also the NAs distribution in terms of molecule carbon number and hydrogen deficiency. Overall, it is concluded that ethyl ether can be used as an alternative to dichloromethane (DCM) given their similar extraction efficiencies and extracted NA profiles. This is important since DCM is known to have metabolic toxicity and transitioning to the safer ethyl ether would eliminate laboratory DCM exposures and risk to human health. Despite the higher extraction efficiency of NAs at pH 2.0, extraction at pH 12.0 could be useful for targeted extraction of low-concentration nonpolar organic compounds in OSPW. This knowledge may assist in the determination of the specific NAs species that are known to have chronic, sub-chronic and acute toxicity to various organisms, and the potential targeting of treatment to these NAs species. [ABSTRACT FROM AUTHOR]

Airborne thermal-infrared (TIR) imaging spectrometry techniques have been used to detect and track methane and other gaseous emissions from a variety of discrete sources in diverse environmental settings, and to enable estimation of the strength of each plume. The high spatial resolution (1–2 m) permits attribution of chemical plumes to their source, while the moderate spectral resolution (44 nm across the 7.5–13.5 μm TIR band) enables identification and quantification of the gaseous plume constituents, even when one is present in considerably greater concentration than the others. Raw imagery was quantitatively analyzed using matched filtering and adaptive coherence techniques. Experiments under controlled conditions demonstrated successful detection of methane point sources at release rates as low as 2.2 kg/h (~ 1 dm 3 /s at NTP). [ABSTRACT FROM AUTHOR]

Abstract: Henry’s law constant (HLC) is an important factor used in environmental risk assessment and fate and transport models to describe mass transfer of chemical between water and air. HLCs and structure–property relationships were assessed for 1,2,4,5-tetrachlorobenzene (TeCB), pentachlorobenzene (PeCB), and hexachlorobenzene (HCB). HLCs were determined using the volatilization rate (kv ) of sparged chemical at 25°C. Despite the assumption that kv should be constant throughout the stripping duration, results indicated that kv decreased over time according to three separate slope regions. Results of ANCOVA indicate that kv is statistically different in the third slope region, which leads to the conclusion that use of the entire stripping data set would lead to biased HLCs. This decrease in kv may be attributed to desorption from sparger surfaces, which has not been considered widely in the literature. Statistical analysis was possible because of the robustness of the current experimental procedure which included numerous replications (15 total spargers) and extensive data points available to discern key slope changes. HLCs determined using the gas stripping technique were 57, 33, and 30Pam3 mol−1 for 1,2,4,5-TeCB, PeCB, and HCB, respectively. In comparison to literature values, current TeCB and HCB HLCs were within wide reference ranges spanning approximately an order of magnitude for each chemical. PeCB HLC of the current study was two times lower than the lowest reference data. [Copyright &y& Elsevier]

Abstract: The sorption behaviour of hydrophobic organic compounds (HOCs) 1,2,4,5-tetrachlor-obenzene (TeCB), pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) to Aldrich humic acid (AHA) and municipal wastewater treatment plant (MWTP) influent colloidal organic carbon (COC) was investigated using the gas-stripping technique. Gas stripping assumptions of gas/water equilibrium and a constant volatilization rate were validated prior to calculation of partitioning parameters. The logK COC coefficients determined for MWTP influent COC were 3.86, 3.89 and 3.19 for TeCB, PeCB and HCB, respectively. Due to the presence of COC, the mass transfer of TeCB, PeCB and HCB with the primary effluent to the secondary biological stage was predicted to increase 8.7%, 9.6% and 1.2%, respectively, based on the measured COC concentration and logK COC values. The calculated increases in apparent solubility for TeCB, PeCB and HCB in the primary effluent were 14.4%, 22.0% and 6.5%, respectively. This partitioning did not follow the expected trend (TeCB < PeCB < HCB) based on hydrophobicity predicted by octanol/water partitioning. The trend observed differed from the current AHA standard and correlation-based trends derived from natural COCs. More experiments with other HOCs are needed to better understand and predict the magnitude and significance of MWTP influent COCs on the fate and transport of HOCs during the MWTP process. [Copyright &y& Elsevier]

Abstract: The ac–dc–ac accelerated testing method is an unconventional method that involves subjecting organic coatings on metallic substrates to cycles of cathodic potential. The ac–dc–ac degradation associated with a standard Army epoxy primer on a steel substrate is reported. The ac–dc–ac procedure was modified to include wetting and drying stages. Experimental results demonstrated the influence that the method had on the barrier property, the diffusion of water, and saturated condition of the primer. A quantitative analysis of the transient potential profile that followed the cathodic potential was performed to address processes of charge transfer, transport, and coating relaxation during this step. [Copyright &y& Elsevier]

Abstract: Cathodic protection models for pipeline and other metallic structures developed to address the presence of coating flaws or holidays do not account explicitly for the presence of a delaminated region surrounding a holiday. The potential drop in the delaminated region was obtained by solving the coupled, non-linear, partial differential, governing equations that describe transport and electrochemical reactions within the delaminated region. The results were used to develop an analytic expression for the potential drop across the delaminated region as a function of delaminated region length and the resistivity of the bulk environment exterior to the holiday. Expressions developed using this approach can be utilized by existing cathodic protection models to deliver improved potential distributions along protected metallic surfaces. The simulations were used to test the commonly employed assumption that transport by diffusion can be neglected in the delaminated region. The influence of diffusion on current was shown to be significant. [Copyright &y& Elsevier]

Abstract: Embedded sensors were used as an in situ corrosion-sensing device for aircraft and vehicular structures protected by organic coatings. Results are presented where changes associated with standard air force aircraft and army vehicle coatings were monitored by embedded sensors. These coatings consisted of a polyurethane topcoat and an epoxy primer, however are formulated to provide different characteristics. The ac–dc–ac testing method was used to accelerate the degradation of these coatings while being immersed in a NaCl medium. Electrochemical impedance spectroscopy and electrochemical noise measurement experiments were used to monitor the induced changes. A comparison of the results between coatings subjected to the ac–dc–ac exposure and coatings subjected to only constant immersion in the NaCl medium is presented. The results were used to demonstrate the effectiveness of the ac–dc–ac method at accelerating the degradation of an organic coating without observably changing the normal mechanism of degradation. The data highlights the different features of the coating systems and tracks them while the coating is being degraded. The aircraft coating was characterized by a high-resistant topcoat that can mask corrosion/primer degradation at the primer/substrate interface whereas the vehicle coating was characterized by a low-resistant topcoat with an effective corrosion inhibiting primer. Details of the ac–dc–ac degradation were evaluated by using an equivalent circuit to help interpret the electrochemical impedance data. [Copyright &y& Elsevier]

Abstract: A standard Air Force polyurethane topcoat/epoxy chromate pigmented primer system was characterized using the thermal cycling method. This method is an accelerated test method for organic coatings that involves exposing the coating to alternating room temperature and elevated temperature cycles under constant immersion. Electrochemical properties were monitored using electrochemical impedance spectroscope for the total topcoat/primer system, the inner layer of primer, and the outer layer of the topcoat. The individual layers were monitored using platinum sensors embedded between the layers. Characterization of a system comprising of two layers of the epoxy chromate pigmented primer was also performed using EIS monitoring, and embedded sensors. The systems were cycled between room temperature, and set temperatures up to 80°C. The barrier property of the topcoat and the bulk resistance of the primer were consistent with Arrehenius behavior. The results obtained were consistent with the intended design of the polyurethane topcoat and chromate primer with the former providing the significant barrier protection, whereas the primer providing the passivating chromate to the metal/coating interface. Analysis of the EIS data obtained from the sensor with an equivalent circuit decoupled the bulk primer properties from the metal/coating interface properties. [Copyright &y& Elsevier]

Screening level risk assessment models are used by many countries to assess the treatability of organic chemicals during the sewage treatment process, especially those that are new to commerce. The performance of one such model, the sewage treatment plant model, is evaluated in the current study by comparing model predictions with actual measurement data collected at various stages of a typical full-scale activated sludge type sewage treatment plant. A suite of ten polycyclic aromatic hydrocarbons (PAHs) with widely varying physico–chemical properties were monitored for the comparison. Model predicted removal efficiencies were in very good agreement with those measured for all ten PAHs. Observed chemical concentrations and their trends at various stages of the sewage treatment process were also well simulated by the model. Results also suggest that a reasonable first approximation estimate of a range for the biodegradation half-life needed for the model may be obtained by dividing reported aqueous biodegradation half-life by scaling factors of 50 and 150. [Copyright &y& Elsevier]

Abstract: A mathematical model was developed to simulate the transient propagation of the cathodic delamination on a coated metal. The model employed porosity and the polarization kinetics at the metal-coating interface that were assumed to be dependent on the local pH. The simulations provided qualitative agreement with published experimental results for a zinc coated system characterized by extremely rapid cathodic delamination. The mathematical model described in this work provides a foundation on which more sophisticated models can be constructed. [Copyright &y& Elsevier]

Species’ rarity is expressed and measured at a variety of spatial scales, and rarity at different scales could be correlated. Considerable empirical evidence has supported a positive correlation between spatial distribution and local numerical abundance of species, which could create a syndrome of rarity for species limited in geographic distribution and occurring at low densities even in their primary habitats. We used auditory-count data and range information for birds in the Tilarán mountains of Costa Rica to examine the abundance–distribution relationship in cloud forest species and to determine if endemic species (limited to Costa Rican–Panamanian highlands or Central America) are locally rare or restricted in ecological distribution. We found a positive correlation between abundance and distribution at the smallest spatial scale: species occupying few sites in the study area had low abundances where they occur. At larger scales, geographical distribution measured categorically was correlated with local ecological amplitude (zones occupied). Local abundance, however, was not correlated across all species with estimates of range size (km2), although most endemics exhibited below-median abundance. Within families with endemics and cosmopolitan species, 72% of narrow endemics were among the rarest species. For most narrow endemics, we rejected the possibility that they are sufficiently specialized within their habitats to reach relatively high densities. A conclusive test of the abundance–distribution relationship at large spatial scales and evaluation of global population size for endemics will require a comprehensive analysis using abundance data from throughout species’ ranges. Such analyses for tropical species will be a long time coming, but it is meanwhile prudent to recognize that many endemics are threatened at several spatial scales, including the risks of small local populations. [Copyright &y& Elsevier]

Abstract: The measurement model technique was used to analyze impedance data associated with Cronidur 30 and M50 steel samples in new and degraded jet engine oil. The analysis for the degraded oil included both determining the error structure associated with the data and evaluating the consistency of the data with Kramers–Kronig relations. Voigt measurement model parameters were used to identify characteristic time constants for new and degraded oils. This information was used to differentiate the impedance responses into bulk oil and alloy-oil interfacial contributions. The analysis presented here represents a step toward understanding the physical processes involved. [Copyright &y& Elsevier]

Sulfamethoxazole (SMX) was effectively removed from aqueous solution via adsorption to a chemically modified biochar created using a simple and rapid microwave (MW) pyrolysis of activated municipal wastewater sludge. Response surface methodology (RSM) was used to maximize SMX adsorption capacity optimizing three independent synthesis parameters including ZnCl 2 concentration (0.5–1.5 mol/L), MW time (3–10 min), and MW power (400–1000 W). ZnCl 2 modified biochar (ZnBC) synthesized under the optimized conditions (ZnCl 2 concentration = 1.5 mol/L, MW time = 8 min, and MW power = 915 W) was analyzed by different characterization techniques including Brunauer Emmett and Teller (BET) surface area analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS), and point of zero charge (pH pzc). ZnCl 2 impregnation coupled with a homogenous MW heating profile led to improved accessibility of surface functional groups with a specific surface area of 214 m2/g and robust porous structure with an average pore volume of 0.127 cm3/g. Adsorption experiments using the optimized ZnBC resulted in a 89% SMX removal efficiency and maximum SMX adsorption capacity of 50.6 mg/g. Isotherm and kinetic analysis suggested multilayer chemical adsorption of SMX over a heterogeneous biochar surface followed by heterogenous pore diffusion into the ZnBC pores. Results showed that acidic pH favors SMX removal through a spontaneous and exothermic process. The application of modified activated sludge-based biochar introduces a new sustainable method for treating pharmaceuticals and recycling waste sludges from wastewater treatment plants. [Display omitted] • Municipal wastewater activated sludge biomass was pyrolyzed via microwave. • Microwave pyrolysis conditions were optimized using response surface methodology. • Improved morphology of modified biochar led to increased specific surface area. • Isotherm models suggested multilayer adsorption of sulfamethoxazole on biochar. • Sulfamethoxazole sorption capacity is pH-dependent peaking at pH= 3 (50.6 mg/g). [ABSTRACT FROM AUTHOR]

Longwave-infrared (LWIR) spectral imaging offers a means for detecting and sourcing halocarbon emissions with high sensitivity, with the principal halocarbon classes of environmental concern being detectable at flux rates of ~0.2–2 kg/h. Broad-area airborne LWIR surveys efficiently locate and speciate halocarbon emissions on local to regional scales and can promote more effective compliance efforts. Similar approaches can also contribute to the effective situational awareness and mitigation of releases resulting from infrastructure damage following catastrophic events of natural origin or occurring as a consequence of human action. Three U.S. urban domains were surveyed: Greater Los Angeles, San Francisco East Bay, and New York City. In each of the California conurbations the most frequently observed halocarbons were HFC-134a, HCFC-22, and HFC-152a while in New York HCFC-22, HFC-32, and HFC-134a were prevalent. The most common radiatively important non-halocarbon agents observed in each locale were carbon dioxide and methane. • Infrared spectral imaging is a high-sensitivity technique for halocarbon detection. • Airborne surveys identify and locate emission hotspots on local to regional scales. • Infrared spectral imaging can facilitate more effective regulatory compliance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Froth reagent scheme for complex base-metal sulphide ore. • Recoveries of 84.0% and 83.8% for chalcopyrite and sphalerite. • Optimum recovery at 3 min grinding and pH 6. • SEM images show co-occurring copper and zinc. Generating a flotation reagent scheme for a complex base-metal sulphide ore using reagents that are commonly found in mineral processing can be a challenging, complex process. Ensuring that optimum operating conditions including particle size, pH, types of reagents, and dosages of reagents are found is critical in establishing a foundation for future research. A modified xanthate reagent scheme was chosen using potassium amyl xanthate (PAX) as the collector, methyl isobutyl carbinol (MIBC) as the frother, copper sulphate as activator, carboxy methyl cellulose (CMC) and zinc sulphate as depressants. The operating conditions that generated the highest recoveries and grades for copper and zinc were found using a grinding time of 3 min and a slightly acidic medium of pH 6 achieving maximum recoveries of 84.0% and 83.8% for chalcopyrite and sphalerite, and grades of 3.9 and 21.0, respectively. These results allow for comparisons to industrial results with ore of a similar composition while simultaneously providing a baseline in which to evaluate the results of future, innovative research. [ABSTRACT FROM AUTHOR]

The Salton Trough lies in the transition between the San Andreas Fault and oblique spreading centers and transform faults in the Gulf of California. The Salton Sea Geothermal Field is the northernmost expression of those spreading centers. In ~ 2007 two ammonia-emitting fumarole fields that had been submerged beneath the Salton Sea were exposed for the first time in nearly 50 years. As the sea level continued to drop these fields have developed a number of boiling pools, mud pots, gryphons and a unique suite of ammonium sulfate minerals. These have been studied over time with long-wave infrared remote sensing coupled with ground truth surveys backed by laboratory analyses of the minerals. Many vents lie at the center of concentric rings of mineralization with systematic occurrence of different minerals from center to edge. Three semi-concentric zones (fumarole, transition and evaporite) have been defined with respect to ammonia-emitting vents and bubbling pools. The scale of these zones range from several meters, localized around individual vents, to that of the fumarole fields as a whole. The fumarole zone is closest to the vents and locally contains cavernous sulfur crystals and significant deposits of gypsum, mascagnite, boussingaultite and other ammonium sulfates. The transition zone comprises a dark brown surficial band of inconspicuous sodium nitrate underlain by anhydrite/bassanite that is thought to have formed by ammonia-oxidizing microbes interacting with the ammonium sulfates of the outer fumarole zone. The evaporite zone is the outermost and contains blödite, thenardite and glauberite, which are typical of the sulfates associated with the shoreline of the Salton Sea. Remote sensing has shown that the mineral zones have remained relatively stable from 2013 to 2017, with minor variations depending on rainfall, temperature and levels of agricultural runoff. [ABSTRACT FROM AUTHOR]

Porous polyvinylidene fluoride (PVDF) polymeric membranes with inclusion of Fe 2 O 3 nanoparticles and multi-walled carbon nanotubes (MWCNTs) were developed for the Fenton-like catalytic degradation of organic contaminants at neutral pH. The PVDF was modified by in situ polymerization with methyl methacrylate to improve its hydrophilicity, and a range of membranes with different Fe 2 O 3 and MWCNTs loadings were casted. The effect of these compositions on membrane morphology, surface functionality and hydrophilicity was investigated by microscopic, spectroscopic and surface characterization techniques. Contact angle measurements showed that MWCNTs did not change the membrane hydrophilicity, while the Fe 2 O 3 was effective in increasing hydrophilicity. The optimum combination of 0.2% MWCNTs and 1% Fe 2 O 3 induced pore formation and improved membrane permeability. The removal efficiency of cyclohexanoic acid (CHA) and humic acids (HAs) were evaluated. Batch studies revealed that 48% of CHA was degraded after 24 h of membrane exposure with H 2 O 2 . For HAs, removal with H 2 O 2 addition was significantly higher than without at 53.1±4.4% and 28.1±4.1%, respectively. These membranes also showed a significant reduction in membrane fouling. Overall, the permeate flux achieved with H 2 O 2 was four times higher as compared to without H 2 O 2 addition which is ascribed to the catalytic oxidation of organic molecules which accumulated at the membrane surface. [ABSTRACT FROM AUTHOR]

Extensive use of pharmaceuticals in public health and animal husbandry has resulted in their frequent detection in a wide variety of environmental water matrices. Lincomycin (LIN) is a widely used lincosamide antibiotic that is relatively persistent in the environment given its chemically stable structure. Biochar-based adsorbents are eco-friendly and inexpensive materials that can be used to remove contaminants from water. This study investigated the interactions between LIN and a microwave-activated biochar (BC) in batch and dynamic adsorption processes. The BC activation process was optimized with consideration of the molarity of the activation agent (H 3 PO 4), microwave heating time, and microwave power. The results indicated the effectiveness of the applied activation process in the BC production with a BET surface area of 1452 m2/g at the optimized condition, exceeding 2 m2/g for the raw biomass. The maximum adsorption capacity of BC for LIN was 190 mg/g, with experiments suggesting that electrostatic interaction may be the dominant factor affecting the adsorption of LIN on BC. In addition, thermodynamic analyses indicated the thermodynamically spontaneous and favorable adsorption of LIN on BC. The results indicate that microwave pyrolysis is an efficient method for creating an effective BC-adsorbent for removing LIN from different water matrices. [Display omitted] • Microwave-activated biochar was prepared to remove lincomycin from water. • The biochar activation process was optimized using the response surface methodology. • Activated biochar was used in batch and dynamic adsorption processes. • The specific surface area of activated biochar was 1452 m2/g. • Electrostatic interaction may be the dominant factor affecting the adsorption of lincomycin. [ABSTRACT FROM AUTHOR]

Arsenite [As(III)] is more mobile and toxic than arsenate [As(V)], making it more difficult and more critical to remove from water. The oxidative adsorption of As(III) is preferred due to its cost and time effectiveness. The chemical mixing process is a common method for preparation of biochar composites, but it is not time-efficient for homogeneous metal impregnation and is challenging to achieve consistent and reproducible physicochemical properties of the composite. The mixing method is even more challenging if two metal oxides are utilized in preparing engineered biochars. The current study proposes a novel microwave- and electrochemical-assisted technique to overcome the shortcomings of the mixing method and create a binary-oxide biochar composite with oxidation and adsorption capabilities. In addition, a new procedure was used to develop a diffusional mass transfer model combined with a genetic algorithm to characterize the adsorption process. Characterization of the fabricated biochar indicated that the deposited Fe and Mn oxides on the biochar surface included a mixture of Mn(II,III,IV) oxides and poorly crystalline α-FeOOH, respectively. The adsorption results suggested a hybrid adsorption mechanism with a high probability of a homogeneous monolayer adsorption process. Based on XANES analyses, no reduction to As(III) was observed for the As(V) adsorbed onto adsorbent, while 79% of the adsorbed As(III) was oxidized to As(V). The intraparticle diffusion and external mass transfer coefficients were estimated using a diffusional mass transfer model. Based on the modeling results, the adsorption of As onto the fabricated adsorbent was mainly controlled by external mass transfer. Overall the As(III) adsorption capacity of untreated biomass increased from 62 to 21,426 μg/g through the modification, indicating the high potential of the proposed procedure for preparation of adsorbents with improved oxidation and adsorption performance. [Display omitted] • Binary oxide biochar composite was prepared using electrochemical modification. • Manganese and iron oxides were formed on the biochar surface. • Deposited manganese oxides oxidized arsenite to arsenate on the biochar surface. • Binary oxide composite was a more efficient adsorbent than single metal oxide. • A mass transfer model combined with genetic algorithm characterized the process. [ABSTRACT FROM AUTHOR]

Abstract: Low concordance of reports across partners has consistently been observed when partners report the frequency of intimate partner violence (IPV) and psychological aggression (PA) in their relationship. Researchers have been unsuccessful in the quest to discover systematic biases across reporters, perhaps due to examining constructs that are not the source of bias (e.g., gender, victim/perpetrator status) or examining potentially fruitful constructs using underpowered statistics or erroneous conceptualizations (e.g., examining variables at a dyadic, rather than an individual, level). We used multilevel modeling with two samples (Ns=88 and 164 couples) to examine husbands'' and wives'' relationship satisfaction as individual-level correlates of husband- and wife-perpetrated IPV and PA reporting concordance. Consistent with prior literature, low to moderate levels of agreement were observed, and gender and victim/perpetrator status were not consistently associated with reporting concordance. In contrast, for both husbands and wives, relationship satisfaction was associated with reporting concordance such that high relationship satisfaction was related to reporting less of one''s partner''s PA than the partner reported, whereas low relationship satisfaction was related to reporting more of one''s partner''s PA than the partner reported. A similar pattern of results emerged for the reporting of IPV, but results did not cross validate between samples. These findings suggest that relationship satisfaction may lead to either reluctance, or increased willingness, to attribute negative relationship events to partner behavior, potentially due to partner blame and relationship schemas. In addition, the influence of individual-level factors may be occluded when aggregated across partners to examine correlates of interpartner reporting concordance. [Copyright &y& Elsevier]

Abstract: Mg-rich primers have been proven to be an adequate alternative for chromate-based coatings for the protection of aluminum alloys from corrosion. The performance of a Mg-rich primer on aluminum 2024-T3 under Prohesion® exposure (ASTM G85) has been monitored using an embedded sensor placed at the surface of the primer and below the topcoat. Electrochemical impedance spectroscopy and noise measurements were conducted to monitor the electrochemical properties of the system beneath the topcoat. The data analysis demonstrates that the sensor is able to detect change in the barrier properties of the topcoat in response to the exposure conditions. [Copyright &y& Elsevier]

In this study, the Fe(III)/WS 2 /peroxymonosulfate (PMS) system was found to remove up to 97% of cyclohexanecarboxylic acid (CHA) within 10 min. CHA is a model compound for naphthenic acids (NAs), which are prevalent in petroleum industrial wastewater. The addition of WS 2 effectively activated the Fe(III)/PMS system, significantly enhancing its ability to produce reactive oxidative species (ROS) for the oxidation of CHA. Further experimental results and characterization analyses demonstrated that the metallic element W(IV) in WS 2 could provide electrons for the direct reduction of Fe(III) to Fe(II), thus rapidly activating PMS and initiating a chain redox process to produce ROS (SO 4 •−, •OH, and 1O 2). Repeated tests and practical exploratory experiments indicated that WS 2 exhibited excellent catalytic performance, reusability and anti-interference capacity, achieving efficient degradation of commercial NAs mixtures. Therefore, applying WS 2 to catalyze the Fe(III)/PMS system can overcome speed limitations and facilitate simple, economical engineering applications. [Display omitted] • Fe(III)/WS 2 /PMS system can achieve 97% removel rate of CHA within 10 min. • •OH, SO 4 •−, and 1O 2 are main ROS in the Fe(III)/WS 2 /PMS system. • W(IV) contained in WS 2 can promoting Fe(III)/Fe(II) cycle by providing electrons. • Fe(III)/WS 2 /PMS system can achieve efficient degradation of commercial NAs. • Fe(III)/WS 2 /PMS system exhibits excellent reusability and anti-interference. [ABSTRACT FROM AUTHOR]

Much of the toxicity in oil sands process-affected water in Athabasca oil sands tailings has been attributed to naphthenic acids (NAs) and associated naphthenic acid fraction compounds (NAFCs). Previous work has characterized the environmental behaviour and fate of these compounds, particularly in the context of constructed treatment wetlands. There is evidence that wetlands can attenuate NAFCs in natural and engineered contexts, but relative contributions of chemical, biotic, and physical adsorption with sequestration require deconvolution. In this work, the objective was to evaluate the extent to which prospective wetland substrate material may adsorb NAFCs using a peat-mineral mix (PMM) sourced from the Athabasca Oil Sands Region (AOSR). The PMM and NAFCs were first mixed and then equilibrated across a range of NAFC concentrations (5–500 mg/L) with moderate ionic strength and hardness (∼200 ppm combined Ca2+ and Mg2+) that approximate wetland water chemistry. Under these experimental conditions, low sorption of NAFCs to PMM was observed, where sorbed concentrations of NAFCs were approximately zero mg/kg at equilibrium. When NAFCs and PMM were mixed and equilibrated together at environmentally relevant concentrations, formula diversity increased more than could be explained by combining constituent spectra. The TOC present in this PMM was largely cellulose-derived, with low levels of thermally recalcitrant carbon (e.g., lignin, black carbon). The apparent enhancement of the concentration and diversity of components in PMM/NAFCs mixtures are likely related to aqueous solubility of some PMM-derived organic materials, as post-hoc combination of dissolved components from PMM and NAFCs cannot replicate enhanced complexity observed when the two components are agitated and equilibrated together. [Display omitted] • Naphthenic acid fraction compounds (NAFCs) were mixed and equilibrated with peat-mineral mix (PMM). • Low sorption of NAFCs to PMM was observed, in contrast to previous reported measurements of NAFCs soil sorption. • Spectral diversity and number of ions were enhanced for NAFC-PMM mixtures relative to spectra from individual mixtures. [ABSTRACT FROM AUTHOR]