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Vertical distribution of phytoplankton is crucial for assessing the trophic status and primary production in inland waters. However, there is sparse information about phytoplankton vertical distribution due to the lack of sufficient measurements. Here, we report, to the best of our knowledge, the first Mie–fluorescence–Raman lidar (MFRL) measurements of continuous chlorophyll a(Chl-a) profiles as well as their parametrization in inland water. The lidar-measured Chl-aduring several experiments showed good agreement with the in situ data. A case study verified that MFRL had the potential to profile the Chl-aconcentration. The results revealed that the maintenance of subsurface chlorophyll maxima (SCM) was influenced by light and nutrient inputs. Furthermore, inspired by the observations from MFRL, an SCM model built upon surface Chl-aconcentration and euphotic layer depth was proposed with root mean square relative difference of 16.5% compared to MFRL observations, providing the possibility to map 3D Chl-adistribution in aquatic ecosystems by integrated active–passive remote sensing technology. Profiling and modeling Chl-aconcentration with MFRL are expected to be of paramount importance for monitoring inland water ecosystems and environments.

Although nanoplastics (NPs) are recognized as emerging anthropogenic particulate pollutants, the occurrence of NPs in the environment is rarely reported, partly due to the lack of sensitive methods for the concentration and detection of NPs. Herein, we present an efficient method for enriching NPs of different compositions and various sizes. Alkylated ferroferric oxide (Fe3O4) particles were prepared as adsorbents for highly efficient capture of NPs in environmental waters, and the formed large Fe3O4–NP agglomerates were separated by membrane filtration. Detection limits of 0.02–0.03 μg/L were obtained for polystyrene (PS) and poly(methyl methacrylate) (PMMA) NPs by detection with pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). When analyzing real water samples from different sources, it is remarkable that PS NPs were detected in 11 out of 15 samples with concentrations ranging from <0.07 to 0.73 μg/L, while PMMA were not detected. The wide detection of PS NPs in our study confirms the previous speculation that NPs may be ubiquitous in the environmental waters. The accurate quantification of PS NPs in environmental waters make it possible to monitor the pollution status of NPs in aquatic systems and evaluate their potential risks.

Through precursor-directed biosynthesis, feeding halogenated (F-, Cl-, Br-, I-) or methoxy-substituted 4-methyl-3-hydroxyanthranilic acid (4-MHA) analogues to the acnGHLM-deleted mutant strain of Streptomyces costaricanusSCSIO ZS0073 led to the production of ten new actinomycin analogues (4–13). Several of the actinomycin congeners displayed impressive antimicrobial activities, with MIC values spanning 0.06–64 μg/mL to clinically derived antibiotic resistant pathogens, including Staphylococcus aureus, Enterococcus faecium, and Candida albicans, with low cytotoxicity.

Members of the abyssomicin class of natural products are characterized by a novel vinylic bridged ether ring. In this study, in vivo gene inactivation, structure elucidation of the accumulated intermediate abyssomicin 6, and in vitro enzyme assays enabled the identification of a cytochrome P450 enzyme, AbmV. AbmV carries out domino reactions involving bridged ether installation and C-11 hydroxylation during the biosynthesis of neoabyssomicins/abyssomicins in S. koyangensisSCSIO 5802.

As a group of new persistent organic pollutants, short-chain chlorinated paraffins (SCCPs) and medium-chain CP (MCCPs) have attracted extensive worldwide interest in recent years. However, the data regarding to the environmental behavior, especially in atmospheric transfer and air–seawater exchange, are still sparse. In this study, seasonal marine boundary layer air and seawater samples were collected from Chinese Bohai sea and a fugacity model was built to evaluate the air–seawater diffusion and deposition flux of CPs. Generally, the total CP levels in atmosphere and seawater samples in summer were higher than those in spring, and CPs existed mostly in the gaseous phase in air and the dissolved phase in seawater. For SCCPs, C10and C11components were the most abundant homologue groups. For MCCPs, the C14homologue dominated in the particle phase of atmosphere and particulate phase of seawater. The logarithmic fugacity ratios (log fa/fw) of higher chlorinated congeners (Cl8to Cl10: 0.71 to 1.32 in May and 1.38 to 2.29 in August) indicated that net deposition was the predominant process, whereas lower chlorinated congeners, especially Cl5homologue groups in August, showed a trend of net volitization (log fa/fw< −0.5). The results of diffusion and dry deposition fluxes indicated that air–seawater gas exchange of CPs was significantly higher than dry deposition in the sampling areas.

Although brominated disinfection byproducts (Br-DBPs) have been reported to form from reactions between bromide, dissolved organic matter (DOM), and disinfectants, their formation during the disinfection of aquaculture seawater via chlorination has been rarely studied. Herein, after 5 days of disinfection of raw aquaculture seawater samples with sodium dichloroisocyanurate (NaDDC), trichloroisocyanuric acid (TCCA) and chlorine dioxide (ClO2), 181, 179, and 37 Br-DBPs were characterized by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Sunlight irradiation of the chlorinated aquaculture seawater with TCCA and NaDDC was found to reduce the formation of Br-DBPs, possibly due to the photodegradation of the important HBrO/HClO intermediate and the degradation of formed Br-DBPs. The formation of Br-DBPs chlorinated by ClO2increased under sunlight irradiation. The number of Br-DBPs formed during chlorination processes agreed well with the total organic bromine (TOBr) content measured by inductively coupled plasma mass spectrometry (ICP-MS). Most of the Br-DBPs were highly unsaturated and phenolic compounds, which were primarily generated through electrophilic substitution by bromine coupled with other reactions. In addition, some emerging aromatic Br-DBPs with high relative intensities were also assigned, and these compounds might be highly lipophilic and could potentially accumulate in marine organisms. Our findings call for further focus on and investigation of the Br-DBPs produced in chlorinated aquaculture seawater.

ABSTRACTSince bacterial quorum sensing system has been verified to regulate many microbial physiological activities, such as virulence factor production and biofilm formation in pathogens, blocking quorum sensing has being recognized as a viable approach for the development of novel therapeutics in treating bacterial infections. In this study, quorum quenching activities of marine actinomycetes isolated from seawater sample were investigated. Out of 56 morphological different strains, 5 strains had been found exhibiting anti-quorum sensing activity against the violacein production of Chromobacterium violaceum12472. One highly active strain HY026 was identified as Streptomyces parvulusbased on the 16S rDNA sequence analysis and morphological features. Spent culture medium of HY026 could also significantly inhibit the biofilm formation of four bacteria. One major active compound named F1-4, accounting for 26.3% of crude extracts, was obtained from HY026 cultures and identified as actinomycin D based on the analysis of the NMR and MS. F1-4 could significantly inhibit the violacein production of C. violaceumwith the inhibition rate of 64.9% but not affect the bacterial growth at the concentration of 12.5 µg/mL. F1-4 could also inhibit the prodigiosin production of Serratia proteamaculans657 with the pigment inhibition zone of 13.5 mm at concentration of 25 µg/disc without affecting the bacterial growth. Another pure compound, cyclic (4-hydroxy-Pro-Phe) was also isolated and identified from this actinomycetes strain. The higher production and easier isolation of actinomycin D from S. parvulusHY026 indicated that this strain could be a potential source of quorum sensing inhibitors.

The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection. Metal organic frameworks (MOFs) have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics, including adjustable structure, strong stability and porosity. Herein, pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions. Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal—organic frameworks. Furthermore, the material exhibits excellent adsorption capacity, with a theoretical maximum copper uptake of 247 mg/g. As proven by XPS and FT-IR analysis, the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66. This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions, and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.

This paper describes a rapid method for the determination of 14 kinds of sulfonamides (SAs) in wastewater using SPE, and LC‐MS/MS with positive ESI (ESI(+)) and selected reaction monitoring (SRM) mode. The SPE was performed on an Oasis hydrophilic‐lipophilic‐balanced (HLB) cartridge. Chromatographic separation on a C18 column was achieved using a binary eluent containing methanol and water with 0.2% formic acid. Typical recoveries of the analytes ranged from 22.3 to 87.0% at a fortification level of 100 ng/L. The LODs in wastewater except sulfathiazole (3 ng/L) could be detected and quantified at levels as low as 1 ng/L. Finally, the method was applied to water from the municipal outlet and the aquaculture wastewater effluent. Sulfamethazine (SM2), sulfamethoxypyridazine (SMP), and sulfamethoxazole (SMZ) were most frequently found in wastewater in a concentration range between 1.2 and 31.7 ng/L.

A comprehensive method was developed for the sensitive and fast determination of trace levels of methyltin compounds in aqueous samples. Tin compounds in aqueous solution at pH 5 were converted to the corresponding volatile hydrides: CH3SnH3, (CH3)2SnH2, and (CH3)3SnH, by reaction with potassium borohydride. A CP-4010 purge and trap injector (PTI) was used to purge analyte species from water directly. The volatile derivatives were base-line separated on a capillary column in an Angilent-6890 gas chromatograph by a suitable temperature program and were detected by a flame photometric detector (FPD). The detection limits were 18 ng L−1for monomethyltin, 12 ng L−1for dimethyltin, and 3 ng L−1for trimethyltin, respectively. This method was successfully applied to the determination of methyltin compounds in different aqueous samples.