A novel modified fenton-like process for efficient remediation of anthracene-contaminated soils before analysis by ultraviolet–visible spectroscopy

Due to the persistence of polycyclic aromatic hydrocarbons (PAHs) in soil and sediments, and their toxic, mutagenic, and carcinogenic effects, the remediation of PAH-contaminated sites is an important role for environment pollution. In this study, the chemical oxidative remediation of anthracene-contaminated soils was investigated by magnetite nanoparticles (Fe3O4) catalyzed Fenton-like oxidation in the presence of hydrogen peroxide 30% (H2O2) and urea-hydrogen peroxide (UHP) at neutral pH. Urea-hydrogen peroxide (UHP), as a safer oxidizing agent, is used for the first time in the Fenton process. The magnetite nanoparticles improved the production of hydroxyl radicals, and the removal of polycyclic aromatic hydrocarbons (anthracene as a model compound) from the soil samples. The structure of Fe3O4 nanoparticles was characterized by FT-IR, XRD, SEM, and vibrating sample magnetometer (VSM). The removal efficiency of anthracene at an initial concentration 2500 (mg kg-1) was 95% for 2.5 mmol by using hydrogen peroxide and 93% for 0.1 mmol of UHP at the optimum oxidation condition. The anthracene reaction was analyzed by ultraviolet-visible spectroscopy (UV-Vis). The UHP safety and efficiency, neutral pH condition, the limited iron leaching and its easy magnetic separation makes magnetite nanoparticles-UHP a promising catalytic system in remediation of polycyclic aromatic hydrocarbons in contaminated soils.

Influence of Oxidation Temperature on Structure and Mechanical Properties of Titanium

Surface oxidation of pure titanium was performed in the atmosphere to increase the mechanical properties. The effect of oxidation temperature (650-900°C) for 2 h on the microstructure, composition, and mechanical properties of the treated samples was investigated using X-ray diffraction, hardness tester and indentation modulus tester, respectively. The diffusion rate of oxygen in grade-2 pure Ti with different processing temperatures discussed in present research. Based on a result of the examination, the surface hardness was increased first and then decreased as the processing temperature increased. And when the processing temperature at 850°C, the surface hardness reached the maximum value. In addition, the Young's modulus of the treated samples also showed a maximum value of 198.9 GPa for a processing temperature of 850°C. An oxidation condition of 850°C is considered optimal as it provides sufficiently high hardness during practical use.

Mass spectral characterization of secondary organic aerosol from urban lifestyle sources emissions

In the present work, we conducted experiments of secondary organic aerosol (SOA) formation from urban lifestyle sources (cooking and vehicle) to characterize the mass spectral features of primary organic aerosol (POA) and SOA using an high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Our results showed that the cooking styles have greater impact on aged COA mass spectra than oxidation condition. However, the oxidation conditions affect the aged HOA spectra more significantly than vehicle operation conditions. In our study, we use mass spectra similarity analysis and positive matrix factorization (PMF) analysis to establish the POA and SOA mass spectra of these two typical lifestyle sources. These mass spectra are used as source constraints in a multilinear engine (ME-2) model to apportion the OA sources in the atmosphere. Comparing with the traditional ambient PMF results, the improved ME-2 model can better quantify the contribution of POA and SOA from life-style sources. Our work, for the first time, establishes the vehicle and cooking SOA source profiles, and can be further used in the OA source apportionment in the ambient atmosphere.

Paleogeographic Characteristics of the Mengyejing Formation in the Simao Basin during Its Depositional Period and Its Indication of Potash Mineralization: A Case Study of MZK-3 Well

In China, pre-Quaternary solid potash deposit has only been discovered in the Simao Basin, and the Lower Cretaceous Mengyejing (MYJ) Formation (Fm.) is the productive layer of potash deposit. In this study, we investigated the clay conglomerates which are distributed in upper and lower members of the potash-bearing salt rock layer. We analyzed the relative contents of major elements (Al2O3, Fe2O3T, MgO, CaO, Na2O, K2O) and trace elements (B, Ba, Co, Cr, Cu, Ga, Mn, Ni, Rb, Sr, V, Zn, Zr) in the samples. The results show that MgO and CaO in the major elements are rich relative to Post Archean Australian Shale (PAAS), whose average enrichment factor values of the MgO (EFMgO) is 2.61 and CaO (EFCaO) is 4.57, and the others major elements are relatively minor; trace elements (B, Ga, Mn, Zr) are rich relative to PAAS, and the others trace elements are minor relative to PAAS. The study of paleogeographic conditions using various parameters shows that the paleoclimate is generally dry and hot during the period of clay conglomerate deposition, but it was warm and humid in certain periods; the main sedimentary environment is weak oxidation condition with strong oxidation conditions in individual periods; the average value of paleosalinity is ~21‰, and the highest is no more than ~92‰. The significance of the paleogeographic characteristics of MYJ Fm. to potash mineralization are as follows: (1) they indicates that the clay conglomerates of MYJ Fm. are not clastic sediments in brine formed by seawater, because the paleosalinity of clay conglomerates deposition period is obviously lower than that of seawater; (2) MYJ potassic salt ore is not formed by evaporation and concentration of seawater in clay conglomerates in the sedimentary basin, because there is no carbonate rock and sulfate rock of corresponding scale after the deposition of clay conglomerates in the basin; (3) clay conglomerates of MYJ Fm. were deposited in continental shallow water basin; (4) the matter source of potash minerals is deep marine strata; (5) in the MYJ Fm. sedimentation period, deep source salt moved to the surface under the background of extensional structure, and the subsequent sedimentary clastic rock formed a protective layer of potash-bearing rock, thus completing the “deep source and shallow mineralization” metallogenic process.

Enrichment Mechanisms of Gallium and Indium in No. 9 Coals in Anjialing Mine, Ningwu Coalfield, North China, with a Preliminary Discussion on Their Potential Health Risks

To provide a comprehensive insight into the enrichment mechanism of gallium and indium in No. 9 coals, eighteen samples were collected from Anjialing mine, Ningwu Coalfield, Shanxi Province for coal petrological, mineralogical and geochemical analyses. The results suggested that Ga and In enrichment mainly hosted in the top horizons, with average concentration coefficients of 8.99 and 2.73 respectively, compared with the rest of horizons (2.46 for Ga and 1.69 for In). Source apportionment indicated that Ga and In were mainly derived from bauxite of Benxi Formation in Yinshan Oldland, while In could originate from felsic magmatic rocks in Yinshan Oldland as well. In addition, weak oxidation condition, medium to intensive weathering, transgression and input of terrestrial higher plants had positive effects on Ga and In enrichment. With the rapid expansion of emerging electronics manufacturing, Ga and In, of which potential risks on human health were neglected previously, were recently considered as hazardous elements. Therefore, this paper also discussed the potential pathways that these elements threatened human health. We suggested that potential risks on environment and human health caused by Ga and In enrichment in coals and coal-related products should be taken into account besides their economic value.

Development and validation of stability indicating assay method for estimation of lumefantrine in bulk and tablet dosage form

Simple, precise, accurate, sensitive, economical, and rapid stability indicating method was developed for the estimation of Lumefantrine in bulk and tablets. Chromatographic analysis was performed on A Hibar C18 (4.6×250 mm, 5μm) column and mobile phase made up of acetonitrile: methanol (50:50 v/v); used for this study. The flow rate of the mobile phase was to 1.2 ml/min; the temperature of the column was adjusted to 40°C and UV analysis was carried out at 234 nm. The degradation studies were performed and the analytical method was validated as per ICH Q2R1 guideline. The Retention time of Lumefantrine was found to be 8.8 min. The developed method was found to be linear in the concentration range of 10-60 μg/ml. The value of the correlation coefficient between peak area and concentration was found to be 0.995. The value of % RSD was found to be within prescribed limits for precision studies which indicate reproducibility of the method. The values of LOD and LOQ were obtained at 14.54 and 44.07 μg/ml, respectively. The results of degradation studies indicate that the drug was found to be stable in acidic, basic, neutral, photolytic, and neutral conditions while degraded in oxidation condition.