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1.
Arch Environ Contam Toxicol ; 78(4): 579-588, 2020 May.
Article in English | MEDLINE | ID: mdl-32123946

ABSTRACT

The occurrence and potential sources of pharmaceuticals and personal care products (PPCPs) in surface waters from a large coastal city Qingdao, North China, were investigated. Forty-five compounds were analyzed by high-performance liquid chromatography-tandem mass spectrometry. The results showed that 28 compounds of PPCPs were detected. The most frequently detected compounds were atrazine, clarithromycin, nonylphenol, and bisphenol A with the detection rates > 90%. Paracetamol showed the highest concentration up to 4400 ng/L (mean 152.5 ng/L), followed by ampicillin (max. 2980 ng/L) with the highest mean concentration (229.3 ng/L), iopromide (max. 1744 ng/L, mean 74.5 ng/L), atrazine (max. 1612 ng/L, mean 96.1 ng/L), and bisphenol A (max. 1384 ng/L, mean 78.3 ng/L). The contamination levels and composition profiles of PPCPs along the rivers flowing through rural and urban areas and in seawater showed large spatial variability. Typical source markers and principle component analysis were used to track and differentiate the potential PPCP sources. The emphases of the study were the influence of animal farming in rural areas on PPCP composition profiles and the ecological risk. The results indicated that PPCPs in Qingdao surface water mainly came from three potential sources, i.e., treated wastewater (effluents from WWTPs), untreated wastewater, and nonpoint sources in agricultural areas.


Subject(s)
Cosmetics/analysis , Environmental Monitoring/methods , Pharmaceutical Preparations/analysis , Rivers/chemistry , Water Pollutants, Chemical/analysis , Agriculture , China , Cities , Risk Assessment , Seawater/chemistry , Wastewater/chemistry
2.
Chem Commun (Camb) ; 56(14): 2206-2209, 2020 Feb 18.
Article in English | MEDLINE | ID: mdl-31976501

ABSTRACT

Reported herein is a visible-light-catalyzed photoredox atom-transfer radical cyclization (ATRC) halo-alkylation of 1,6-dienes with α-halo-ketones as the ATRC reagent. This process exhibits high atom economy, high step economy, and high redox economy, which can directly construct a 4-bromo-3,3-dialkyl-octahydro-indol-2-one core under mild conditions in one pot, and lutidine is found to be the key promoter for this ATRC process.

3.
Org Lett ; 21(21): 8615-8619, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31613111

ABSTRACT

A method using aroyl chlorides as atom-transfer radical cyclization agents in a novel visible-light photocatalytic aroylchlorination reaction is developed. The overall transformation involves the formation of two new C-C bonds and one new C-Cl bond in a one-pot process. The advantages of this reaction include high atom/step/redox economy, mild conditions, operational simplicity, and broad substrate scopes.

4.
Huan Jing Ke Xue ; 36(2): 457-63, 2015 Feb.
Article in Chinese | MEDLINE | ID: mdl-26031070

ABSTRACT

Estuary is an important area contributing to the global carbon cycle. In order to analyze the spatial-temporal distribution characteristics of the dissolved inorganic carbon (DIC) in the surface water of Yellow River estuary. Samples were collected in spring, summer, fall, winter of 2013, and discussed the correlation between the content of DIC and environmental factors. The results show that, the DIC concentration of the surface water in Yellow River estuary is in a range of 26.34-39.43 mg x L(-1), and the DIC concentration in freshwater side is higher than that in the sea side. In some areas where the salinity is less than 15 per thousand, the DIC concentration appears significant losses-the maximum loss is 20.46%. Seasonal distribution of performance in descending order is spring, fall, winter, summer. Through principal component analysis, it shows that water temperature, suspended solids, salinity and chlorophyll a are the main factors affecting the variation of the DIC concentration in surface water, their contribution rate is as high as 83% , and alkalinity, pH, dissolved organic carbon, dissolved oxygen and other factors can not be ignored. The loss of DIC in the low area is due to the calcium carbonate sedimentation. DIC presents a gradually increasing trend, which is mainly due to the effects of water retention time, temperature, outside input and environmental conditions.


Subject(s)
Carbon/analysis , Environmental Monitoring , Estuaries , Seasons , Calcium Carbonate , Carbon Isotopes , China , Chlorophyll , Chlorophyll A , Rivers , Spatio-Temporal Analysis , Temperature
5.
Ying Yong Sheng Tai Xue Bao ; 26(11): 3554-60, 2015 Nov.
Article in Chinese | MEDLINE | ID: mdl-26915215

ABSTRACT

Methyl halides are the major carrier of halogens in the atmosphere, and they play an important role in tropospheric and stratospheric ozone depletion. Meanwhile, methyl halides can act as greenhouse gases in the atmosphere, and they are also environmentally significant because of their toxicity. Coastal salt marshes, the important intertidal ecosystems at the land-ocean interface, have been considered to be a large potential natural source of methyl halides. In this paper, the research status of the natural source or sink of methyl halides, the mechanisms of their emission from coastal salt marshes and affecting factors were summarized. In view of this, the following research fields need to be strengthened in the future: 1) Long time-scale and large region-range researches about the emission of methyl halides and the evaluation of their source and sink function, 2) Accurate quantification of contribution rates of different plant species and various biological types to fluxes of methyl halides, 3) Further researches on effects of the tidal fluctuation process and flooding duration on methyl halides emission, 4) Effects of the global change and human activities on methyl halides emission.


Subject(s)
Air Pollutants/chemistry , Wetlands , Atmosphere , Human Activities , Plants , Salinity
6.
Huan Jing Ke Xue ; 33(2): 370-8, 2012 Feb.
Article in Chinese | MEDLINE | ID: mdl-22509569

ABSTRACT

Understanding the chemical characteristics of groundwater in the Yellow River Delta is very important. It can provide a useful reference for the development and construction of the Yellow River Delta High-efficiency Ecological Economic Zone and ecological regulation in the lower Yellow River. Based on partitioning the sediment environment and the recharge-runoff-discharge system, we studied the hydrochemical features and causes of shallow groundwater in the Yellow River Delta by mathematical statistics and geostatistics, Piper diagram, ion ratios and so on. Following results are obtained: 1) Major cations and anions such as Na+, Mg2+, Ca2+, Cl(-), SO4(2-), HCO3(-) and TDS concentrations range from 0.1-25.0 g x L(-1), 3.6-3 815.0 mg x L(-1), 5.6-3 377.0 mg x L(-1), 0.1-45.1 g x L(-1), 24.2-4 947.0 mg x L(-1), 62.6-850.0 mg x L(-1) and 0.4-80.7 g x L(-1). Average ion concentrations further indicate that Cl(-), Na+ and TDS concentrations are high while HCO3(-), CO3(2-) and K+ concentrations are very low in the study area. 2) The Cl(-) and TDS concentrations of shallow groundwater possess conspicuous directional spatial variability and gradually increase along the groundwater flow direction, showing that Cl(-) is the most critical ion of shallow groundwater. 3) From the recharge area to the discharge area, shallow groundwater changes from the Na+ -Mg2+ -Ca2+ -Cl(-) -SO4(2-) facies to the Na -Mg2 + -Ca2+ -Cl(-), Mg2+ -Na+ -Ca2+ -Cl(-) and Na+ -Mg2+ -Cl(-) facies, finally evolves into Na+ -Cl(-) facies in the coast. 4) Ion ratios indicate that the following main hydrochemical processes are inferred to control the shallow groundwater chemical composition: mixing, evaporation concentrating, mineral dissolution, cation exchange and adsorption and human activities. These findings strongly suggest that changes of the Yellow River water course and seawater intrusion are key drivers to form the chemical characteristics of shallow groundwater in the region.


Subject(s)
Environmental Monitoring , Groundwater/chemistry , Magnesium/analysis , Sodium/analysis , China , Chlorides/analysis , Groundwater/analysis , Oceans and Seas , Rivers , Seawater/chemistry
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