A feasible and rapid analysis for the simultaneous determination of sulfonamides (SAs), tetracyclines (TCs), fluoroquinolones (FQs), macrolides (MACs) and nitrofurans (NFs) in livestock manure and soils was established by solid-phase extraction (SPE)-ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS). A total of 32 manure and 17 amended soil samples from the Liaoning and Tianjin areas in Northern China were collected for analysis. The largest detected frequencies and concentrations in manure samples were those of TCs (3326.6 ± 12,302.6 μg/kg), followed by FQs (411.3 ± 1453.4 μg/kg), SAs (170.6 ± 1060.2 μg/kg), NFs (85.1 ± 158.1 μg/kg), and MACs (1.4 ± 4.8 μg/kg). In general, veterinary antibiotics (VAs) were detected with higher concentrations in swine and chicken manure than in cattle manure, reflecting the heavy usage of VAs in swine and chicken husbandry in the studied area. Furthermore, higher residues of antibiotics were found in piglet and fattening swine manure than in sow manure. In addition, TCs were the most frequently (100 %) detected antibiotics in amended soil with higher concentrations (up to 10,967.1 μg/kg) than any other VAs. The attenuation of SAs was more obvious than TCs in amended soil after fertilization, which can most likely be attributed to the stronger sorption of TCs than SAs to soil organic matter through cation exchange. This study illustrated the prevalence of TCs detected in both animal manure and fertilized agricultural soils in Northern China, which may increase the risk to human health through the food chain. Thus, TCs should be given more attention in the management of veterinary usage in livestock husbandry.

Toxic elements present in airborne particulate matter (PM) are associated with human health effects; however, their toxic characteristics depend on the source of their origins and their concentrations in ambient air. Twenty four elements (Al, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Se, Sr, Te, Tl, and Zn) in 12 different size fractions of PM ranging from 10 nm to 10 μm were characterized in Singapore during two different atmospheric conditions (smoke haze and non-haze periods) in 2012 for the first time. In addition, their possible sources were identified based on backward air trajectory analysis and principal component analysis (PCA). The health implications of inhalable particles were assessed using a human airway deposition model, the Multiple-Path Particle Dosimetry model (MPPD). The results concerning particle-bound trace elements are interpreted in terms of coarse (PM₂.₅₋₁₀), fine (PM₂.₅), ultrafine (PM₀.₀₁₋₀.₁, 0.01 μm < Dp < 0.10 μm), and nano (PM₀.₀₁₋₀.₀₅₆, 0.01 μm < Dp < 0.056 μm) particles. The ratios of elemental concentrations measured between the smoke haze episode and the non-haze period in coarse, fine, ultrafine, and nano particles varied from 1.2 (Bi) to 6.6 (Co). Both the PCA and backward trajectory analysis revealed that trans-boundary biomass-burning emissions from Indonesia were primarily responsible for enhanced concentrations of particulate-bound elements during the smoke haze episode. The particle depositions in the respiratory system were higher during the smoke haze episode compared to the non-haze period. The study finds that ultrafine and nano particles present in the atmosphere have higher tendencies to be deposited into the deeper parts of the respiratory system, compared to coarse and fine particles.

The novel catalysts of Mn/Ti-doped carbon xerogel (CX) were synthesized for efficient degradation of microcystin-LR (MC-LR) in the water surface discharge plasma reactor. The degradation efficiency of 79.7 % was obtained in 6 min with 0.5 wt% Ti impregnation of CX, and it would be increased with higher amount of Ti. In particular, Mn-doped CX resulted in larger mesoporous particle diameter and higher porosity in the matrix, and thereby, the highest efficiency of 88.6 % was achieved for CX-Ti-Mn. The possible degradation pathway of MC-LR was elucidated on the basis of the LC-MS analysis. It demonstrated that Adda chain was cleaved from the MC-LR cyclic peptide by OH radical attack after plasma discharge in the presence of catalysts, and the generated nontoxic products can be further easily degraded in the biological treatment. Therefore, Mn/Ti-doped carbon xerogel is promising as the catalyst for the improvement of MC-LR degradation in the water surface discharge plasma reactor.

Microbial control agents offer alternatives to chemical pest control, as they can be more selective than chemical insecticides. The present study evaluates the mosquito larvicidal and pupicidal potential of fungus mycelia using ethyl acetate and methanol solvent extracts produced by Aspergillus terreus against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti. The A. terreus mycelia were extracted after 15 days from Sabouraud dextrose broth medium. The ethyl acetate extracts showed lethal concentration that kills 50 % of the exposed larvae (LC₅₀) and lethal concentration that kills 90 % of the exposed larvae (LC₉₀) values of the first, second, third, and fourth instar larvae of An. stephensi (LC₅₀ = 97.410, 102.551, 29.802, and 8.907; LC₉₀ = 767.957, 552.546, 535.474, and 195.677 μg/ml), Cx. quinquefasciatus (LC₅₀ = 89.584, 74.689, 68.265, and 67.40; LC₉₀ = 449.091, 337.355, 518.793, and 237.347 μg/ml), and Ae. aegypti (LC₅₀ = 83.541, 84.418, 80.407, and 95.926; LC₉₀ = 515.464, 443.167, 387.910, and 473.998 μg/ml). Pupicidal activity of mycelium extracts was tested against An. stephensi (LC₅₀ = 25.228, LC₉₀ = 140.487), Cx. quinquefasciatus (LC₅₀ = 54.525, LC₉₀ = 145.366), and Ae. aegypti (LC₅₀ = 10.536, LC₉₀ = 63.762 μg/ml). At higher concentration (500 μg/ml), mortality starts within the first 6 h of exposure. One hundred percent mortality occurs at 24-h exposure. The overall result observed that effective activity against selected mosquito larvae and pupae after 24 h was a dose and time-dependent activity. These ensure that the resultant mosquito population reduction is substantial even where the larvicidal and pupicidal potential is minimal. The FTIR spectra of ethyl acetate extract reflect prominent peaks (3448.32, 3000.36, 2914.59, 2118.73, 1668.21, 1436.87, 1409.02, 954.33, 901.13, and 704.67 cm⁻¹). The spectra showed a sharp absorption band at 1314.66 cm⁻¹ assigned to wagging vibration of the C–H group. The band at 1023.59 cm⁻¹ developed for C–O and C=N, respectively, and was commonly found in carboxylic acid and amine groups. GC–MS analysis of ethyl acetate extracts showed the presence of six compounds, of which the major compounds were identified as n-hexadecanoic acid (15.31 %) and methyl 12,15-octadecadienoate (31.989 %), based on their peak molecular weight. The HPLC analysis result highlights that the A. terreus ethyl acetate extract was compared with pure n-hexadecanoic acid which resulted in similar retention time of 19.52 and 19.38, respectively. Thus, the active compound produced by this species would be more useful against vectors responsible for diseases of public health importance. This is the first report on mosquito larvicidal and pupicidal activity of ethyl acetate extract produced by A. terreus species.

Steady-state and transient-state photolysis experiments were conducted to investigate the degradation of organic ultraviolet filter diethylamino hydroxybenzoyl hexyl benzoate (DHHB) in the aqueous solution by UV/H₂O₂. Results showed that the obvious degradation of DHHB was not observed under UV irradiation (λ = 254 nm), and the DHHB degradation was conducted due to the oxidation by hydroxyl radical (HO·). While the H₂O₂ concentration was between 0.05 and 0.10 mol L⁻¹, the highest DHHB degradation efficiency was obtained. The lower solution pH favored the transformation of DHHB, and the coexisting Cl⁻ and NO₃ ⁻ ions slightly enhanced the conversion. The degradation of DHHB by HO· followed a pseudo-first-order kinetic model with different initial DHHB concentrations. By intermediate products during DHHB oxidation and laser flash photolysis spectra analysis, a primary degradation pathway was proposed.

The concentrations of total petroleum hydrocarbons (TPH), n-alkanes (n-C₈ through n-C₄₀), and 16 polycyclic aromatic hydrocarbons (PAHs) in soils were determined to assess the level of organic contamination in soils from the Da-gang Petrochemical Industry Park with several big state-run enterprises, a recent rapid flourishing park in China. The results showed that the concentration of TPH in soil was high, up to 20 ng/g–12.8478 %; in particular, the content in most sites ranged from 1 to 2 %. Thus, it is clear that soil environment in the Da-gang Petrochemical Industry Park has been seriously polluted by TPH according to the Nemerow pollution index method. Furthermore, the average concentration of Σ(n-C>₁₆ through n-C₃₄) in 30 sampling sites was above the maximum limit set for F3 under all the conditions in the Canada-wide standards for petroleum hydrocarbons (PHC CWS) with 43.33–93.33 % soil samples exceeding F3 standards, and n-alkanes possessing higher concentrations were proved much abundant alkanes in this study. Besides, the predominance of even n-alkanes and lower carbon preference index (CPI) demonstrated that n-alkanes in surface soils were mainly caused by anthropogenic inputs, while the concentration of Σ₁₆-PAHs was in the range of 1652.5–8217.3 ng/g and the BaA/(BaA + Chr) and Flu/(Flu + Pyr) ratios indicated that pyrogenic PAHs may be the dominant PAHs in most soils with the contribution of petrogenic hydrocarbons in some sites.

The purpose of this work was to study the efficiency of different treatments, based on the combination of O₃, H₂O₂, and TiO₂, on fresh surface water samples fortified with wild strains of Escherichia coli. Moreover, an exhaustive assessment of the influence of the different agents involved in the treatment has been carried out by kinetic modeling of E. coli inactivation results. The treatments studied were (i) ozonation (O₃), (ii) the peroxone system (O₃/0.04 mM H₂O₂), (iii) catalytic ozonation (O₃/1 g/L TiO₂), and (iv) a combined treatment of O₃/1 g/L TiO₂/0.04 mM H₂O₂. It was observed that the peroxone system achieved the highest levels of inactivation of E. coli, around 6.80 log after 10 min of contact time. Catalytic ozonation also obtained high levels of inactivation in a short period of time, reaching 6.22 log in 10 min. Both treatments, the peroxone system (O₃/H₂O₂) and catalytic ozonation (O₃/TiO₂), produced a higher inactivation rate of E. coli than ozonation (4.97 log after 10 min). While the combination of ozone with hydrogen peroxide or titanium dioxide thus produces an increase in the inactivation yield of E. coli regarding ozonation, the O₃/TiO₂/H₂O₂ combination did not enhance the inactivation results. The fitting of experimental values to the corresponding equations through non-linear regression techniques was carried out with Microsoft® Excel GInaFiT software. The inactivation results of E. coli did not respond to linear functions, and it was necessary to use mathematical models able to describe certain deviations in the bacterial inactivation processes. In this case, the inactivation results fit with mathematical models based on the hypothesis that the bacteria population is divided into two different subgroups with different degrees of resistance to treatments, for instance biphasic and biphasic with shoulder models.

Mercury from anthropogenic activities is a pollutant that poses significant risks to humans and the environment. In soils, mercury remediation can be technically challenging and costly, depending on the subsurface mercury distribution, the types of mercury species, and the regulatory requirements. This paper introduces the chemistry of mercury and its implications for in situ mercury remediation, which is followed by a detailed discussion of several in situ Hg remediation technologies in terms of applicability, cost, advantages, and disadvantages. The effect of Hg speciation on remediation performance, as well as Hg transformation during different remediation processes, was detailed. Thermal desorption, electrokinetic, and soil flushing/washing treatments are removal technologies that mobilize and capture insoluble Hg species, while containment, solidification/stabilization, and vitrification immobilize Hg by converting it to less soluble forms. Two emerging technologies, phytoremediation and nanotechnology, are also discussed in this review.

Sorption of volatile organic compounds on the inner surface of polymer sampling bags leads to important underestimations of the real headspace concentration. Introducing a wide range of volatiles in a two-phase system containing Nalophan revealed that recoveries decreased down to 57 % in a period of 22 h. In this work, a phase ratio variation approach is investigated to quantify the degree of scalping, and thus enabling to compensate for sorption phenomena. This method requires limited measurements, without the need for time-consuming calibrations. By spiking identical amounts of volatiles in three two-phase systems, each having unique polymer volume/mass ratios β (β ₁ = 0, β ₂ = 80.9, β ₃ = 161.9), individual partitioning coefficients could be experimentally determined for a wide range of compounds. Additionally, a correlation was found between these partitioning coefficients and the liquid molar volume for a number of aliphatic, aromatic, and oxygenated compounds.

Mercury (Hg) contamination is a global issue due to its anthropogenic release, long-range transport, and deposition in remote areas. In Kejimkujik National Park and National Historic Site, Nova Scotia, Canada, high concentrations of total mercury (THg) were found in tissues of yellow perch (Perca flavescens). The aim of this study was to evaluate a possible relationship between THg concentrations and the morphology of perch liver as a main site of metal storage and toxicity. Yellow perch were sampled from five lakes known to contain fish representing a wide range in Hg concentrations in fall 2013. The ultrastructure of hepatocytes and the distribution of Hg within the liver parenchyma were analyzed by transmission electron microscopy (TEM) and electron energy loss spectrometry (EELS). The relative area of macrophage aggregates (MAs) in the liver was determined using image analysis software and fluorescence microscopy. No relation between general health indicators (Fulton’s condition index) and THg was observed. In line with this, TEM examination of the liver ultrastructure revealed no prominent pathologies related to THg accumulation. However, a morphological parameter that appeared to increase with muscle THg was the relative area of MAs in the liver. The hepatic lysosomes appeared to be enlarged in samples with the highest THg concentrations. Interestingly, EELS analysis revealed that the MAs and hepatic lysosomes contained Hg.