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Nowadays, the harm of antibiotics residues in environments to human health and ecological safety has been causing more and more attention. In this paper, a biochar based iron material (MBC) was used to activate persulfate (PS) for the removal of sulfadiazine (SDZ) from aqueous solution. Experiment results indicate that the degradation and mineralization of SDZ by MBC/PS system reached 91.79 and 60 % within 60 min under the optimal reaction conditions, respectively. MBC/PS system exhibited a better performance on SDZ removal compared with MBC/H2O2 system. The addition of Cu2+ ion could enhance the degradation of SDZ by MBC/PS system. PO43-, Cl- and SO42- had a certain degree of inhibitory effect on the SDZ degradation. Both radicals and non-radical species such as SO4•-, •OH and 1O2 participated in the degradation reaction of SDZ by MBC/PS system, but •OH was the main radical species responsible for SDZ degradation. The liquid chromatograph-mass spectrometer (LC-MS) technique was used to identify the intermediate products of SDZ, and it was proposed that the degradation of SDZ might be achieved through hydrolyzation, hydroxylation, deamination and amino-oxidization processes. A possible reaction mechanism involving a synergistic effect between PS homogeneous and heterogeneous activation processes as well as both radicals and non-radicals reactions was finally proposed.

Nowadays, environmental problems caused by residual antibiotics are getting increasing attention. In the present work, peroxymonosulfate (PMS) was firstly employed for the enhanced degradation of norfloxacin (NOF) by a calcium-based Ag3PO4 composite (Ca-Ag3PO4) under visible light irradiation. Experiment results show that NOF removal in Ca-Ag3PO4/PMS/visible light process was higher than the sum of that in Ca-Ag3PO4/visible light and Ca-Ag3PO4/PMS processes. This significant enhancement of NOF removal was mainly due to a synergistic effect between photocatalysis of Ca-Ag3PO4/visible light process and Fenton reaction of Ca-Ag3PO4/PMS process. The inhibitory effects of water quality components on NOF removal followed: Humic acid (HA) > PO43-> HCO3−> NO3−> Cl−. NOF and co-existing heavy metals (ie., Cr(VI) and Ni(II)) or organic compounds like tetracycline (TC) could be simultaneously removed. Both PMS and H2O2 exhibit positive effects on the removal of NOF, but PMS could more effectively improve NOF removal compared with H2O2. An excellent PMS decomposition had been achieved in Ca-Ag3PO4/PMS/visible light process. HO•, SO4•− and 1O2 all took part in NOF degradation by Ca-Ag3PO4/PMS/visible light process, but both HO• and SO4•− might be primary species for NOF degradation. A plausible degradation pathway of NOF in Ca-Ag3PO4/PMS/visible light process was thereby proposed to proceed through ring-opening cracking hydroxylation and elimination reactions reactions. The enhanced reaction mechanism for the degradation of NOF in Ca-Ag3PO4/PMS/visible light process was also proposed.

In this study, FeS2@SiO2 microspheres were firstly employed as a heterogeneous catalyst to activate persulfate (PS) for the degradation of bisphenol A (BPA) from aqueous solutions. The most relevant findings revealed that UV irradiation induced a significant improvement in the degradation of BPA by the FeS2@SiO2 microspheres/PS system. Nearly 100% of BPA degradation by the FeS2@SiO2 microspheres/PS/UV system was achieved within 120 min at reaction conditions of 1 mM PS, 0.066 mM BPA, 1.0 g/L FeS2@SiO2 microspheres and pH 3.0. A high performance on the degradation of BPA might be attributable to a synergistic effect between the PS/UV and the FeS2@SiO2 microspheres/PS catalytic processes. It was found that the BPA degradation could be inhibited by the coexisting anions like Cl−, HCO3− and PO43− to different extents at much higher concentrations, whereas NO3− had a negligible effect. Organic acids such as ethylene diamine tetra-acetic acid (EDTA) and oxalic acid (OA) would lead to an enhancement with a lower dosage, whereas a significantly negative effect was observed at much higher dosages. Radical scavenging tests revealed that the SO4 − radicals prevailed over HO . A total of seven intermediates during the degradation of BPA were identified by GC/MS, and a possible reaction pathway and mechanism of BPA degradation by the FeS2@SiO2 microspheres/PS/UV system was proposed. This study demonstrated a simple water treatment method involving the use of low cost natural iron minerals for organic pollutants removal.

Dissolved phosphorus (P), an important bioavailable nutrient element, is one of the key indicators of eutrophication levels, and has been routinely measured for decades in aquatic environments. The current EPA recommended colorimetric method has been criticized for its time-consuming step of sample preparation and generation of toxic waste through the use of heavy metal catalysts. In this study, a fast, accurate, and interference-free method for the determination of dissolved P in environmental waters based on inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was developed. This ICP-MS/MS was operated in the MS/MS mode to provide an interference-free measurement. The developed method exhibited excellent linearity (R2 = 0.9999) over a concentration range of 0.5–500 μg L−1, with a limit of detection of 8.1 ng L−1 in 5% nitric acid solutions. The recoveries (90%–105% in water samples) and the concentrations determined by this method were in good agreement with those determined using the recommended colorimetric method. Comparing with the colorimetric method, the proposed method for determination of dissolved P exhibited great advantages such as shorter experiment time, lower limit of detection and higher sample throughput.

Composition and types of triacylglycerols (TAGs) in edible oils are closely related to our health. It is of vital significance to develop fast and high-efficiency methods for determination of TAGs. In this manuscript, qualitative analysis of TAGs was demonstrated using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). 2,5-Dihydroxybenzoic acid (DHB) was employed as matrix and dichloromethane was used as solvent for dissolving the edible oils. With laser power of 15%, laser frequency of 100 Hz, and 100 laser shots, relative standard deviation (RSD) less than 9% was obtained. Different kinds of edible oils could be directly distinguished from each other using MS and tandem MS (MS/MS) results. With confidence level of 95%, principal component analysis (PCA) results showed that 34 different kinds of edible oils were clearly classified. Moreover, down to 5% of doped canola in olive was identified directly, indicating that MALDI-FTICR-MS has the potential for rapid analysis and screening of edible oils.

In recent years, a serious threat of antibiotic residues in aquatic environments to human health and ecological security has become increasingly widespread attention. In this study, this is the first report on an alternative strategy on enhanced degradation of amoxicillin (AMX) and norfloxacin (NOF) by TiO2@nZVI/persulfate (PS) process under UV irradiation. Results revealed that a signficantly synergistic effect on AMX degradation had been achieved in TiO2@nZVI/PS/UV process due to the photocatalysis and Fenton-like reactions. NO3–, HCO3–, PO43- and humic acid exhibited inhibitory effects on AMX degradation, whereas Cl- was negligible on that. The degradation of AMX decreased as the addition of Cr(VI) concentrations increased, whereas the correspond values were enhanced when a low Cu(II) concentration was introduced. TiO2@nZVI/PS/UV process was the most efficient for activating PS decomposition. HO•, SO4•− and 1O2 were all generated in TiO2@nZVI/PS/UV process, but HO• and SO4•− were the dominant radical species for AMX degradation. The AMX intermediates products identified by LC-MS system confirmed AMX was effectively degraded through hydroxylation and deamination reactions. A better performance on the simultaneous removals of AMX and NOF by TiO2@nZVI/PS/UV process could be achieved at lower concentration conditions, and the simultaneous reaction mechanism was thereby proposed base on expriment results.

Magnesium slag is a byproduct of the magnesium industry. It has not been commonly used in the construction industry due to the poor hydration reactivity and soundness risk induced by a high content of MgO. However, magnesium slag has hydraulic potential for similar mineral compositions to Portland cement. This study aims to investigate the potential use of magnesium slag as a mineral admixture in cement concrete. The influence of magnesium slag content and fineness on the workability, mechanical properties and durability of concrete was discussed. Results showed that the concrete fluidity increased with increasing magnesium slag content. The fineness of magnesium slag in this study showed a slight influence on the fluidity. Magnesium slag was not beneficial to the early strength development of the concrete due to the retarding effect on hydration, but it had a positive effect on the later strength. It could also optimize the long-term properties of concrete with reduced drying shrinkage and an improvement of sulfate- and frost- resistant properties. Finally, as a mineral admixture in concrete, magnesium slag with an optimum content of 30% and a specific surface area of 485 m2/kg was suggested.

The study characterized the enrichment, ecological risk and possible source of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in sediments from a typical mariculture bay. The concentrations of the metals were analyzed in sediments collected from Zhelin bay. The distribution variation was examined during the past decade, which had an increase tendency till 2011. The enrichment factor and geoaccumulation indices suggested Pb, As, Cu and Zn were minor enrichment and unpolluted to moderately polluted, and Ni at cage mariculture area was moderately-severe enrichment and strongly polluted. This area had medium to high ecological risk, especially at the northwest coastal area of semi-closed bay, with high-medium to high ecological risk. Correlation and principal component analyses indicated that most of heavy metals, especially for As, Pb and Ni, primarily resulted from the combustion of gasoline and diesel fuel and the ship protective layer.

Three new indole diketopiperazine alkaloids, aspergillines A-C (1–3), together with one new polyketide, aspergillone A (4), were isolated from the solid cultures of an endophytic fungus Aspergillus cristatus. Aspergilline A is the first bicyclo[2.2.2] diazaoctane indole alkaloid where the diketopiperazine structure is constructed from tryptophan and alanine. The structures were determined by spectroscopic analysis and their absolute configurations were determined through single-crystal X-ray diffraction and electronic circular dichroism (ECD) spectroscopy. Aspergillone A exhibited moderate antibacterial activities against Bacillus subtilis and Staphylococcus aureus with MIC50 values of 8.5 and 32.2 μg/mL, respectively.

Nowadays, nanoscale zero valent iron (nZVI) has been extensively applied for the decontamination of various pollutants, but passivation of nZVI severely affects its reactivity in use. In this study, ultrasound (US)-assisted catalytic reduction of Cr(VI) by an acid mine drainage based nZVI (AMD-nZVI) coupling with FeS2 system was systematically examined. Results show that the presence of FeS2 and US induced a synergistic enhancement of Cr(VI) removal by AMD-nZVI. Nearly 98% of Cr(VI) removal was achieved by AMD-nZVI/FeS2/US process within 60 min under optimal reaction conditions. Several coexisting substances with lower concentration including Pb(II), Ni(II), bisphenol A (BPA) and 2,4-diclorophenol (2,4-DCP) could be effectively removed in simultaneous manner with Cr(VI) removal. The inhibitory order of water matrix species on Cr(VI) removal was NO3− > PO43− > HCO3− > Ca2+ > Mg2+ > Cl−, and a serious suppression effect was induced by humic acid (HA). Addition of ethylene diamine tetra-acetic acid (EDTA) and citric acid (CA) could enhance Cr(VI) removal rate. An enhanced reaction mechanism was proposed, which involved the regeneration of more Fe2+ and H+ by AMD-nZVI/FeS2/US process, leading to the reduction of Cr(VI) by AMD-nZVI and FeS2 into Cr(III) species inculding Cr2O3 and Cr(OH)3. This study well demonstrates that AMD-nZVI/FeS2/US process is considered as a potential candidate for the remediation of Cr(VI) in real wasterwater.

Titanium dioxide (TiO2) photoelectrodes that offer high light absorption and efficient charge separation hold great promise in photocatalysis. In this study, a simple and controllable method for fabricating hierarchical TiO2−x photoelectrodes by coupling femtosecond laser processing and anodization is proposed. The fabricated photoelectrodes consist of microcones (approximately 150,000 per square centimetre) covered with large quantities of nanotubes. The hierarchical structures possess significant light-trapping effect, meanwhile, oxygen vacancies were simultaneously introduced through laser processing with anodization, which can be attributed to the fs-laser mediated lattice phase transformation (polycrystalline and amorphous layer) of titanium. With the synergistic effects of hierarchical structures and oxygen vacancies, the hierarchical TiO2−x electrode exhibited a narrowed bandgap (1.95 eV) and remarkable light absorption. Especially under visible light, this photoelectrode demonstrated 15-fold photocurrent enhancement and double the usual photodegradation rate of methylene blue. This morphological control and defect introduction method may be extensively used in efficient solar utilisation.