In the present investigation seaweeds of macroalgae like Kappaphycus alvarezii, Gracilaria salicornia and Gracilaria edulis used as novel biosorbent in native (KA, GS, GE) and ethanol modified (EKA, EGS, EGE) for Rhodamine B (RB) removal from aqueous solution in batch process. Effect of various biosorption parameters such as pH, initial concentration of RB, biosorbent dosage and contact time were studied. The maximum biosorption capacity determined as 9.84 (KA), 11.03 (GS), 8.96 (GE), 112.35 (EKA), 105.26 (EGS) and 97.08 mg/g (EGE), respectively towards the removal of RB from aqueous solutions. Better removal of RB was observed using EKA, EGS, and EGE biosorbents at 2.0 pH. The characterizations of the biosorbents were performed using Scanning Electron microscope and Fourier Transform Infrared Spectroscopy. Biosorption equilibrium data evaluated using Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Jovanovic isotherm model. The Langmuir isotherm model best suited the equilibrium data for all the biosorbents studied. The rate of RB removal subjected to kinetic analysis using pseudo-first-order, pseudo-second-order, intra-particle diffusion and Elovich models. Pseudo-second-order kinetic model better described the experimental data of the RB biosorption. Desorption studies performed using 0.1 M sodium hydroxide as eluting agents for regeneration and recycle analysis. The recyclability of the six biosorbents showed consistent biosorption capacity towards RB removal up to the entire three cycles. The studied biosorbents sourced from large volume and easily available, further biosorption performance indicated that the KA, GS, GE, EKA, EGS and EGE could be used as efficient, alternative and eco-friendly biosorbents for the removal of harmful dyes in the environment.

Alternative transportation fuels (ATFs) can reduce air pollution. However, the influence of conventional fuels—diesel and gasoline, and particularly ATFs on photochemical air pollution is not well-characterized, limiting assessments of ATFs and air quality. This is mainly due to frequent use of lumped chemical mechanisms by related atmospheric modeling. Here we hypothesized that applying a chemical mechanism that is specifically developed according to both emission fractions and photochemical ozone creation potential of volatile organic compounds (VOCs) is key to gaining reliable insights into the impact of transportation fuels on photochemistry. We used a heterogeneous chemical mechanism with 927 reactions and relatively detailed emission inventories to specifically meet the requirements for reliable simulation of the effect of exhaust emissions from vehicles fueled by selected model fuels—diesel, gasoline, and mixtures of 15% gasoline with 85% ethanol (E85) or 85% methanol (M85)—on photochemistry. These dispersion-box model simulations revealed a strong influence of atmospheric background balance between VOCs and nitrogen oxides (NOX = [NO] + [NO2]) on the impact of exhaust emissions on photochemistry, with higher tendency toward ozone (O3) formation or destruction for more VOC-limited or NOX-limited conditions, respectively. Accordingly, higher [NOX]/[VOC] exhaust emission, such as from diesel and M85, resulted in lower O3, not only locally but also downwind of the emission. This offers a new perspective and measure for transportation fuel assessment. Rapid conversion of O3 to hydroxyl and hydroperoxyl radicals downwind of the exhaust emission indicates the importance of simulating the impact of road transportation on photochemistry at high spatial and temporal resolution. Peroxyacetyl nitrate formation was more sensitive to VOC emission under VOC-limited conditions than to NOX emission under NOX-limited conditions. Secondary formaldehyde dominated over primary emitted formaldehyde several minutes after emission. These findings should be verified using a 3D modeling study under varying meteorological conditions.

The government of China has announced an ambitious plan to expand the mandatory use of ethanol blended gasoline fuels by 2020. Given the dissimilarity in fuel properties between China and other countries with ethanol blending practices, it is necessary to assess the energy and environmental impacts of ethanol blending. In this study, we prepared two types of ethanol blended fuels (E10, with ethanol contents of approximately 10%) with lower contents of aromatics (ELA) and olefins (ELO), respectively, compared with the market China 5 gasoline. Nine in-use gasoline vehicles varying by manufacturer, engine technology, model year, and emission standard level were analyzed using a chassis dynamometer, which followed the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). Two major positive effects from using E10 fuels could be observed in this study. First, tested turbocharged gasoline direct injection (GDI) vehicles could gain reductions in CO₂ emission, fuel consumption and energy consumption by switching to the higher-octane-number ELO. This finding, along with the engine development trends in the automotive industry (e.g., downsizing and higher compression ratio), may have a synergistic effect to deliver greater energy efficiency in the future. Second, the two ethanol blended fuels could be more effective in reducing the particle mass (PM) and particle number (PN) emissions than the levels of using China 5 gasoline. Notably, the benefit of using ELO was more significant, with average emission reductions of 35% for the PM and of 44% for the PN. However, ELA and ELO possibly increased emissions of gaseous pollutants for certain vehicles in the study, but the intra-vehicle differences between the various fuel groups were not statistically significant (not significant, p > 0.05, t-test). We suggest that more measurements under various environmental conditions and comprehensive air quality simulations should be conducted to better understand the environmental impacts of ethanol blending in China.

While (N-ethyl perfluorooctanesulfonamido ethanol)-based phosphates (SAmPAPs) have been proposed as a group of perfluorooctanesulfonate (PFOS) precursors, investigation of their occurrence and fate has been limited to SAmPAP diester. In this study, SAmPAP diester and triester were simultaneously determined in freshwater sediment from Taihu Lake using a newly developed UPLC-MS/MS method, and their biotransformation to PFOS in lake sediment was investigated. SAmPAP diester and triester were detected in sediments with a detection frequency of 56% and 88%, and their mean concentrations were 0.24 ± 0.11 ng/g dry weight (dw) and 0.12 ± 0.03 ng/g dw, respectively. The SAmPAP diester/triester ratio in sediment was 1.1 ± 4.2, much lower than that (6.7) observed in the technical product, and the positive correlation was found between the concentrations of SAmPAP diester and PFOS in sediments (r² = 0.45, p = 0.01), suggesting that SAmPAP diester would be biotransformed to PFOS in the lake sediment. The microbial degradation test in the lake sediments further clarified that SAmPAP diester was biodegraded to PFOS, but SAmPAP triester was highly recalcitrant to microbial degradation. This study suggests that the occurrence of SAmPAP diester in freshwater lake sediments may be an important precursor of PFOS.

Hydrocarbons, CO, NOx, NH₃, N₂O, CO₂ and particulate matter emissions affect air quality, global warming and human health. Transport sector is an important source of these pollutants and high pollution episodes are often experienced during the cold season. However, EU vehicle emissions regulation at cold ambient temperature only addresses hydrocarbons and CO vehicular emissions. For that reason, we have studied the impact that cold ambient temperatures have on Euro 6 diesel and spark ignition (including: gasoline, ethanol flex-fuel and hybrid vehicles) vehicle emissions using the World-harmonized Light-duty Test Cycle (WLTC) at −7 °C and 23 °C. Results indicate that when facing the WLTC at 23 °C the tested vehicles present emissions below the values set for type approval of Euro 6 vehicles (still using NEDC), with the exception of NOx emissions from diesel vehicles that were 2.3–6 times higher than Euro 6 standards. However, emissions disproportionally increased when vehicles were tested at cold ambient temperature (−7 °C). High solid particle number (SPN) emissions (>1 × 10¹¹ # km⁻¹) were measured from gasoline direct injection (GDI) vehicles and gasoline port fuel injection vehicles. However, only diesel and GDI SPN emissions are currently regulated. Results show the need for a new, technology independent, procedure that enables the authorities to assess pollutant emissions from vehicles at cold ambient temperatures.Harmful pollutant emissions from spark ignition and diesel vehicles are strongly and negatively affected by cold ambient temperatures. Only hydrocarbon, CO emissions are currently regulated at cold temperature. Therefore, it is of great importance to revise current EU winter vehicle emissions regulation.

We evaluated three types of functionalized, graphene-based materials for activating persulfate (PS) and removing (i.e., sorption and oxidation) sulfamethoxazole (SMX) as a model emerging contaminant. Although advanced oxidative water treatment requires PS activation, activation requires energy or chemical inputs, and toxic substances are contained in many catalysts. Graphene-based materials were examined herein as an alternative to metal-based catalysts. Results show that nitrogen-doped graphene (N-GP) and aminated graphene (NH2-GP) can effectively activate PS. Overall, PS activation by graphene oxide was not observed in this study. N-GP (50 mg L−1) can rapidly activate PS (1 mM) to remove >99.9% SMX within 3 h, and NH2-GP (50 mg L−1) activated PS (1 mM) can also remove 50% SMX within 10 h. SMX sorption and total removal was greater for N-GP, which suggests oxidation was enhanced by increasing proximity to PS activation sites. Increasing pH enhanced the N-GP catalytic ability, and >99.9% SMX removal time decreased from 3 h to 1 h when pH increased from 3 to 9. However, the PS catalytic ability was inhibited at pH 9 for NH2-GP. Increases in ionic strength (100 mM NaCl or Na2SO4) and addition of radical scavengers (500 mM ethanol) both had negligible impacts on SMX removal. With bicarbonate addition (100 mM), while the catalytic ability of N-GP remained unaltered, NH2-GP catalytic ability was inhibited completely. Humic acid (250 mg L−1) was partially effective in inhibiting SMX removal in both N-GP and NH2-GP systems. These results have implications for elucidating oxidant catalysis mechanisms, and they quantify the ability of functionalization of graphene with hetero-atom doping to effectively catalyze PS for water treatment of organic pollutants including emerging contaminants.

Rapid temperature rise in Arctic permafrost impacts not only the degradation of stored soil organic carbon (SOC) and climate feedback, but also the production and bioaccumulation of methylmercury (MeHg) toxin that can endanger humans, as well as wildlife in terrestrial and aquatic ecosystems. Currently little is known concerning the effects of rapid permafrost thaw on microbial methylation and how SOC degradation is coupled to MeHg biosynthesis. Here we describe the effects of warming on MeHg production in an Arctic soil during an 8-month anoxic incubation experiment. Net MeHg production increased >10 fold in both organic- and mineral-rich soil layers at warmer (8 °C) than colder (−2 °C) temperatures. The type and availability of labile SOC, such as reducing sugars and ethanol, were particularly important in fueling the rapid initial biosynthesis of MeHg. Freshly amended mercury was more readily methylated than preexisting mercury in the soil. Additionally, positive correlations between mercury methylation and methane and ferrous ion production indicate linkages between SOC degradation and MeHg production. These results show that climate warming and permafrost thaw could potentially enhance MeHg production by an order of magnitude, impacting Arctic terrestrial and aquatic ecosystems by increased exposure to mercury through bioaccumulation and biomagnification in the food web.

To investigate the chemical components, sources, and interactions of particulate matter (PM) and volatile organic compounds (VOCs), a field campaign was implemented during the spring of 2018 in nine cities in northwestern (NW) China. PM was mainly contributed by organic matter and water-soluble inorganic ions (41% for PM₁₀ and approximately 60% for PM₂.₅ and PM₁). Two typical haze patterns were observed: anthropogenic pollution type (AP-type), wherein contributions of sulfate, nitrate, and ammonium (SNA) increased, and dust pollution type (DP-type), wherein contributions of Ca²⁺ increased and SNA decreased. Source appointment suggested that regional sources contributed close to half to PM₂.₅ pollution (40% for AP-type and 50% for DP-type). Thus, sources from regional transport are also important for haze and dust pollution. The ranking of VOC concentrations was methanol > acetaldehyde > formic acid + ethanol > acetone. Compared with other cities, there are higher oxygenated VOCs (OVOCs) and lower aromatics in NW China. The relationships between VOCs and PM were discussed. The dominating secondary organic aerosols (SOA) formation potential precursors were C₁₀–aromatics, xylene, and styrene under low–nitrogen oxide (NOx) conditions, and benzene, C₁₀–aromatics, and toluene dominated under high–NOx conditions. The quadratic polynomial was the most suitable fitting model for their correlation, and the results suggested that VOC oxidations explained 6.1–10.8% and 9.9–20.7% of SOA formation under high–NOx and low–NOx conditions, respectively.

Particulate matter exposure and related chemical changes in drinking water have been associated with health problems and inflammatory disorders. This study aimed to examine the effect of orally administered ash-water dilution on the gut of mice under normal and inflammatory conditions.Balb/c mice received ash-released soluble and dust-suspended components in the drinking water for 14 days. On day 7, animals were intrarectally instilled with TNBS in ethanol or flagellin from Salmonella typhimurium in PBS. At sacrifice, colon segments were collected and histologic damage, mRNA expression and cytokine levels in tissue were evaluated. In addition, these parameters were also evaluated in IL-10 null mice.We found that mice that received 5% w. fine-ash dilution in the drinking water worsened colitis signs. Weight loss, shortening of the colon, tissue edema with mucosa and submucosa cell infiltration and production of pro-inflammatory cytokines and chemokines were enhanced compared to control mice. A more pronounced inflammation was observed in IL-10 null mice. In addition, markers of NLRP3-dependent inflammasome activation were found in animals exposed to ash.In conclusion, ingestion of contaminated water with dust-suspended particulate matter enhanced the inflammatory response in the gut, probably due to alteration of the gut barrier and promoting an intense contact with the luminal content. This study critically appraises the response for fine particulate matter in uncommon illnesses reported for volcanic ash pollution. We suggest actions to enable better prediction and assessment the health impacts of volcanic eruptions.

Benzothiazoles (BTHs), benzotriazoles (BTRs), and benzenesulfonamides (BSAs) are chemicals used in several industrial and household applications. Despite these compounds are emerging pollutants, there is still a lack of information about their presence in outdoor air samples. In this paper, we developed a new method for the quantification of BTHs, BTRs, and BSAs in airborne particulate matter (PM₁₀). The extraction of fourteen analytes from PM₁₀ was accomplished by microwave-assisted extraction (MAE) using an environmentally friendly mixture of water and ethanol. SPME was used to analyze the target compounds from the MAE extract by gas chromatography-tandem mass spectrometry (SPME-GC-MS/MS), eliminating additional sample clean-up steps. The best working conditions for MAE and SPME were examined multivariately by experimental design techniques. The target compounds were quantified in selected reaction monitoring acquisition mode. The proposed method was carefully validated, and the achieved results were satisfactory in terms of linearity, lower limit of quantification (picograms per cubic meter), intra- and inter-day accuracy (81–118% and 82–114%, respectively), and precision (repeatability and reproducibility in the range 2.3–17% and 7.4–19%, respectively). The application in a real monitoring campaign showed that the developed protocol is a valuable and eco-friendly alternative to the methods proposed so far.