A fragment constant QSAR model for evaluating the EC50 values of organic chemicals to Daphnia magna.

The quantitative relationship between the median effective concentration (EC50) of organic chemicals to Daphnia magna and the number of molecular fragments was investigated based on experimental EC50 values for 217 chemicals derived from the literature. A fragment constant model was developed based on a multivariate linear regression between the number of fragments and the logarithmically transformed reciprocal values of EC50. Functional correction factors were introduced into the model. The model was verified using an independent set of randomly selected data. The mean residual of the final model was 0.4 log-units. The robustness of the model was discussed based on the results of three jackknife tests.     

Human exposure and health risk of alpha-, beta-, gamma- and delta-hexachlorocyclohexane (HCHs) in Tianjin, China

The dynamic exposures to HCHs of individuals born between the years 1913 and 1993 in Tianjin have been simulated by connecting a fugacity model (IV) with a multimedia exposure model. Ingestion is the most important pathway for human beings to take up HCHs, and concentrations in the human body correlate with body weight changes. Accumulations of HCHs were derived assuming that the degradation in human body behaved linearly. The health risk of exposure to HCHs was measured using cancer risk and loss of life expectancy (LLE), and LLE was modified from its original definition to incorporate a dynamic calculation that takes variances in exposure into account. Monte-Carlo simulations were run to analyze the uncertainties of the model.     

农林生物质在含铬废水处理中的应用

农林生物质作为低成本吸附剂在环境污染治理中日益受到重视。综述了农林生物质在含铬废水处理中的应用研究进展，分析了生物质处理含铬废水的机理、影响因素，指出了生物质法处理含铬废水的发展方向。     

改性粉煤灰及其处理废水的机理

应用正交设计的基本理论,研究了PDMDAAC(聚二甲基二烯丙基氯化铵)改性粉煤灰的最佳条件,并将改性粉煤灰用于模拟印染废水的处理,探索了改性粉煤灰处理废水的机理。结果表明,在原PDMDAAC的pH下．控制PDMDAAC的浓度为40g／L,恒温30℃．反应1h为最佳改性工艺,改性粉煤灰处理废水的机理以吸附电中和为主。     

Research status,challenges and future prospects of renewable synthetic fuel catalysts for CO2 photocatalytic reduction conversion

Environmental Science and Pollution Research - In recent years, with global climate change, the utilization of carbon dioxide as a resource has become an important goal of human society to achieve...     

Removal and recovery of uranium (VI) from aqueous solutions by residual sludge and its biochars

Environmental Science and Pollution Research - The removal and recovery of uranium (VI) from water solutions are critical for energy and environmental security. In this study, hydrochar at 100,...     

The associations of air pollution exposure during pregnancy with fetal growth and anthropometric measurements at birth: a systematic review and meta-analysis

Environmental Science and Pollution Research - Fetal growth has been demonstrated to be an important predictor of perinatal and postnatal health. Although the effects of maternal exposure to air...     

In situ hydrothermal fabrication of visible light-driven g-C3N4/SrTiO3 composite for photocatalytic degradation of TC

Environmental Science and Pollution Research - A series of g-C3N4/SrTiO3 (CN/SrTiO3) composites with the different mass ratio of g-C3N4 were prepared by facile in situ hydrothermal growth method,...     

Characteristics of single atmospheric particles in a heavily polluted urban area of China: size distributions and mixing states

To investigate the chemical composition, size distribution, and mixing state of aerosol particles on heavy pollution days, single-particle aerosol mass spectrometry was conducted during 9–26 October 2015 in Xi’an, China. The measured particles were classified into six major categories: biomass burning (BB) particles, K-secondary particles, elemental carbon (EC)–related particles, metal-containing particles, dust, and organic carbon (OC) particles. BB and EC-related particles were the dominant types during the study period and mainly originated from biomass burning, vehicle emissions, and coal combustion. According to the ambient air quality index, two typical episodes were defined: clean days (CDs) and polluted days (PDs). Accumulation of BB particles and EC-related particles was the main reason for the pollution in Xi’an. Most types of particle size were larger on PDs than CDs. Each particle type was mixed with secondary species to different degrees on CDs and PDs, indicating that atmospheric aging occurred. The mixing state results demonstrated that the primary tracers were oxidized or vanished and that the amount of secondary species was increased on PDs. This study provides valuable information and a dataset to help control air pollution in the urban areas of Xi’an.

Graphical abstract

     

Effects of taxonomy,sediment, and water column on C:N:P stoichiometry of submerged macrophytes in Yangtze floodplain shallow lakes,China

Carbon (C), nitrogen (N) and phosphorus (P) are the three most important essential elements limiting growth of primary producers. Submerged macrophytes generally absorb nutrients from sediments by root uptake. However, the C:N:P stoichiometric signatures of plant tissue are affected by many additional factors such as taxonomy, nutrient availability, and light availability. We first revealed the relative importance of taxonomy, sediment, and water column on plant C:N:P stoichiometry using variance partitioning based on partial redundancy analyses. Results showed that taxonomy was the most important factor in determining C:N:P stoichiometry, then the water column and finally the sediment. In this study, a significant positive relationship was found between community C concentration and macrophyte community biomass, indicating that the local low C availability in macrophytes probably was the main reason why submerged macrophytes declined in Yangtze floodplain shallow lakes. Based on our study, it is suggested that submerged macrophytes in Yangtze floodplain shallow lakes are primarily limited by low light levels rather than nutrient availability.