[Influencing Mechanism of Precipitation Pollution Intensity in Qinhuai River Basin Based on Random Forest].

Analyzing the distribution characteristics of precipitation pollution intensity in the basin and identifying the main factors affecting the precipitation pollution intensity are the important basis for realizing the accurate management of diffused pollution. Based on the surface water quality data from four typical sections of the main stream of Qinhuai River Basin and rainfall data collected from 2021 to 2022, the distribution characteristics of precipitation pollution intensity in the basin were analyzed, and representative natural and social factors were selected to construct models of the precipitation pollution intensity of ammonia nitrogen （NH-N）, permanganate index, and total phosphorus （TP） based on random forest algorithm. Additionally, the main driving factors of precipitation pollution intensity were identified, and the influencing mechanism was analyzed.

Occurrence, distribution, and ecological risks of antibiotics and antibiotic resistance genes in the surface waters of Gaoyou Lake, China.

This work examined the occurrence characteristics and ecological risks of 31 antibiotics across five classes and seven ARGs in the surface waters of Gaoyou Lake. A total of 27 antibiotics, spanning four classes, were detected in the surface waters of Gaoyou Lake, with an overall concentration ranging from 57.5 to 114 ng/L and an average of 78.

[Determination of nine aromatic amines in water by cloud point extraction-gas chromatography-mass spectrometry].

Aromatic amines are a class of compounds bearing amino groups on their benzene rings; these compounds are important raw materials for the industrial production of rubber chemicals, pesticides, dyes, pharmaceuticals, photosensitive chemicals, and agricultural chemicals. Research has revealed that some aromatic amines teratogenetic, carcinogenic, and mutagenic properties. Given the high toxicity and potential harm caused by aromatic amines, monitoring their levels in water sources is critical.

[Seasonal Variations, Size Distributions, and Sources of Chemical Components of Submicron Particulate Matter in Nanjing].

Size-segregated particulate matter (PM) samples were collected in different seasons from 2016 to 2017 at the Xianlin Campus of Nanjing University. Mass concentrations of water-soluble inorganic ions, carbonaceous components, and elements were analyzed for PM with an aerodynamic diameter ≤ 1.1 μm (PM; <0.

Evaluating the influence of constant source profile presumption on PMF analysis of PM by comparing long- and short-term hourly observation-based modeling.

Hourly PM speciation data have been widely used as an input of positive matrix factorization (PMF) model to apportion PM components to specific source-related factors. However, the influence of constant source profile presumption during the observation period is less investigated. In the current work, hourly concentrations of PM water-soluble inorganic ions, bulk organic and elemental carbon, and elements were obtained at an urban site in Nanjing, China from 2017 to 2020.

[Transport Influence and Potential Sources of Ozone Pollution for Nanjing During Spring and Summer in 2017].

In this study, the 24-hour backward trajectories of air mass at ground level(10 m)in Nanjing were calculated by using the HYSPLIT model with the NCEP global reanalysis data from April 1st to October 31st, 2017. The backward trajectories were then combined with the hourly concentration data of O in Nanjing for trajectories clustering analysis and potential pollution sources analysis. The results show that in 2017, the maximum daily 8 h running average O level in Nanjing was around 12-261 μg·m with 58 days of O pollution in Nanjing, mainly in the spring and summer.

High time-resolved PM composition and sources at an urban site in Yangtze River Delta, China after the implementation of the APPCAP.

In this study, hourly concentrations of PM water-soluble inorganic ions, bulk organic carbon (OC), and elemental carbon (EC) were monitored from 1/1/2017 to 12/31/2017 and validated using filter-based offline analysis at an urban site in Nanjing, China. Compared with 2013 or before, the annual average of PM concentration (36.5 ± 32.