环境科学最新文献

As an emerging pollutant, microplastics exist widely in the environment. At present, the research on microplastics mainly focuses on the atmosphere, ocean, river, and other environmental media. Soil-groundwater has become a significant sink and has received increased interest in recent years. However, the understanding of the transformation behavior and environmental effects of microplastics in the soil-groundwater environment is not yet well understood. Therefore, this review mainly focused on： ① the present research status and progress of microplastics in the soil-groundwater； ② the source and distribution of microplastics； ③ the biological and non-biological transformation of microplastics； and ④ the non-biological enrichment, biological enrichment, and transport effects of microplastics. Additionally, in order to better understand the transformation behavior and environmental effects of microplastics in soil-groundwater in the future, this review systematically summarized and analyzed the shortcomings and limitations of microplastics research status and supplemented and prospected future research directions.

Trace organic contaminants （TrOCs） in reclaimed water can pose potential ecological and health risks during long-term reuse, but the current water quality standards have not restricted their limits. For preventing and controlling the potential risks from TrOCs, an integrated method EHL for identifying priority pollutants in reclaimed water was proposed. This method followed three steps： First, a meta-analysis was performed to assess the exposure of TrOCs in reclaimed water, and a database of TrOCs exposure （E） was established. Then, those hazardous pollutants of particular concern were selected from the E database based on the consensus mechanism, and a dataset of hazardous TrOCs （H） in reclaimed water was established. Finally, the risk quotient of candidates in the H dataset was calculated, and according to the risk-based prioritizing, a final list of priority TrOCs （L） in reclaimed water was recommended. To determine the procedure of EHL, the priority pollutants for reclaimed water in China were identified. Based on literature data from the past 30 years, a total of 32 TrOCs of high concern were selected. Six TrOCs with the highest risk were recommended as an executive priority list for reclaimed water management, including formaldehyde, bis（2-ethylhexyl） phthalate （DEHP）, 17β-estradiol, erythromycin, sulfamethoxazole, and ibuprofen. The EHL method could effectively identify the priority pollutants in reclaimed water and other water environments, and it is expected to play a crucial role in water quality safety evaluation and management.

To investigate the spatial and temporal distribution characteristics and assess the ecological risks associated with emerging contaminants （ECs） in the Beijiang drinking water source, non-targeted screening was conducted using the ultra-high performance liquid chromatography-mass spectrometry technique （UPLC-MS） for one year （June 2022 to May 2023）. This study also involved the quantitative detection of eight typical ECs. The results showed that through the non-targeted screening, a total of 346 pollutants were identified, with industrial materials, pharmaceuticals, and pesticides being the predominant pollutants, collectively accounting for 88.2%. Concentrations of eight representative ECs ranged from n.d （undetected） to 180 ng·L^-1, with detection rates exceeding 80% for six of them. Notably, higher concentrations were found in endocrine disruptors such as bisphenol A （BPA） and 4-nonylphenol （4-NP）, along with the pesticides atrazine （ATZ） and propisochlor （PPS）, with median concentrations ranging from 8.12 to 35.58 ng·L^-1. The concentrations of ATZ, PPS, roxithromycin （ROX）, and ibuprofen （IBU） were significantly higher in the spring season compared to those in other seasons （P<0.05）. Elevated ecological risk levels （RQ>1） were observed at sampling point 1 （S1） and sampling point 3 （S3） for ATZ and Lomefloxacin （LOM）, while for 4-NP, it was determined to be high only at sampling site 2 （S2）. Given their high detection rates and ecotoxicity, particular attention should be paid to ATZ and 4-NP. The concentration level of ATZ exhibited significant seasonal variation due to its agricultural origin, so it is recommended to strengthen control during spring. Overall, this research provides critical insights into a comprehensive understanding of the presence and impact of ECs in this specific region.

Cities are gathering places for residents, industries, and energy consumption, and the carbon emissions generated by urban residents' consumption are becoming increasingly prominent. Under the "dual carbon" goal, how to effectively guide the transformation of urban households' lifestyles and achieve consumption side carbon reduction has become an important issue. Based on questionnaire surveys and face-to-face interviews in the main districts of Hangzhou, the total amount and component of household consumption carbon reduction potential in Hangzhou were calculated by adopting a carbon emission coefficient model, and the relevant factors influencing various types of household consumption behaviors and carbon reduction potential were analyzed through virtual regression models and binary logistic regression. Our results showed that the consumption carbon reduction potential of different groups of residents in the four dimensions of food, clothing, housing, and transportation was significantly different, and electricity consumption had significant direct and indirect impacts on household consumption behaviors and carbon reduction potentials. Age and income were the key factors leading to significant differences in the carbon reduction potential of household consumption. Economic interests and environmental emotional factors were the main factors that affected the transformation of residents' family lifestyle, and their strengths and weaknesses were different. Personal habits, demonstration effects of surrounding people, time costs, etc., were the main reasons affecting residents' willingness to transform their lifestyles. The findings therefore had important implications for climate change mitigation and policy measures associated with lifestyle. On the premise of ensuring stable economic development and improving the well-being of residents, differentiation guides the lifestyle choices of community residents providing reference for better realization of the "double carbon" goal.

Promoting the efficient synergy between low-carbon economy and high-quality development is of great significance for achieving the "dual carbon" strategy on schedule. Taking the panel data from 13 cities of the Beijing-Tianjin-Hebei urban agglomeration from 2006 to 2021 as the research subjects, the coupling coordination degree model, panel vector autoregressive model, and factor analysis model were constructed to explore the spatial and temporal differentiation and driving mechanism of coupling and coordination between low-carbon economy and high-quality development. The results showed that： ① From a temporal perspective, the degree of coupling and coordination in the Beijing-Tianjin-Hebei urban agglomeration had been slowly increasing but remained in a state of mild imbalance. From a spatial perspective, the synergistic effect formed a typical 'core-sphere' structure with Beijing and Tianjin as the core. ② There was a synergistic effect between low-carbon economy and high-quality development, but this effect had a certain lag and would gradually weaken in the long run. ③ From the perspective of the driving force, the role of economic development and resource utilization was significantly stronger than that of scientific and technological innovation. Although the overall driving force during the study period was constantly improving, there was still a big gap in spatial distribution, and it is necessary to strengthen the role of driving force according to local conditions.

Based on Ozone （O₃） Monitoring Instrument satellite remoting sensing data and reanalysis meteorological data, an analysis was conducted on the spatiotemporal distribution and trends of tropospheric nitrogen dioxide （NO₂） and formaldehyde （HCHO） in Guangdong Province from 2015 to 2020. The study also examined the changing characteristics of O₃ generation sensitivity in relation to meteorological parameters. The results indicated that during 2015-2020, the tropospheric NO₂ column concentration in Guangdong Province exhibited a distribution pattern with the Pearl River Delta （PRD） Region as the high-value center gradually decreasing towards the surrounding areas, with the most substantial decline observed in the Pearl River Delta. The HCHO column concentration showed a pattern of higher values in the PRD and lower values in the other regions. While most areas exhibited a decreasing trend in HCHO column concentration, the spatial distribution was more dispersed compared to that of NO₂. In most regions, the ratio of HCHO to NO₂ （FNR） showed an increasing trend. The area under VOCs-NO_x synergistic control decreased, whereas the area under NO_x control increased. By 2020, the proportions of VOCs control area, VOCs-NO_x synergistic control area, and NO_x control area in Guangdong Province were 0.5%, 13.1%, and 86.4%, respectively. The FNR value showed an increasing trend； a positive correlation with 2 m temperature, relative humidity, downward surface shortwave radiation, and boundary layer height； and a negative correlation with 10 m wind speed and sea level pressure. The three most influential meteorological factors were downward surface shortwave radiation（DSSR）, relative humidity, and 2 m temperature, impacting the FNR value the most.

The urban belt along the Yellow River in Ningxia, located in the middle and upper reaches of the Yellow River, serves as the population and economic center of Ningxia. Quantitatively analyzing the spatiotemporal distribution characteristics of the fraction of vegetation cover （FVC） in this region and its driving factors is of great significance for promoting ecological protection and the construction of a leading area for high-quality development in the Yellow River Basin. In this study, Landsat satellite remote sensing data were utilized to derive the vegetation cover from 2001 to 2020 in the cities along the Yellow River in Ningxia using a pixel-based binary model. The spatial pattern and spatiotemporal changes were analyzed. Additionally, meteorological data and topographic information for the same period in this region were combined. Sen+Mann-Kendall trend analysis, Hurst index, and parameter-optimized geographical detector models were used to analyze the driving factors. The results indicated： ① From 2001 to 2020, there was a significant overall increasing trend in vegetation cover in the urban belt along the Yellow River in Ningxia （P<0.01）, with a growth rate of 0.25% per annum. The 20-year average FVC was 33.38%, and the vegetation cover was at a relatively low level. In terms of spatial distribution, the vegetation was high in the northeast and low in the southwest, and the main types were very low vegetation coverage and low vegetation coverage. ② During the 20 years, the vegetation condition of the urban belt along the Yellow River in Ningxia had been significantly improved, and the portion of the area with improved vegetation cover accounted for 62.60%, which was much larger than that of the degraded area, and the average coefficient of variation of FVC was 0.098, which was good for the overall stability. ③ The area with H value of FVC less than 0.5 accounted for 66.15%, which showed strong anti-continuance, the area of FVC with improving trend accounted for 34.84%, the area of continuously stable and unchanged area accounted for 7.8%, the area with degrading trend accounted for 52.9%, and the future trend of FVC was uncertain in 9.0% of the area. ④ The analysis of driving factors revealed that land use type was the primary factor influencing the spatial distribution of vegetation cover in the urban belt along the Yellow River in Ningxia. The explanatory power （Q value） of interactions among various factors was higher than that of individual factors, demonstrating synergistic and nonlinear relationships among them, with no independent relationships. Risk detection showed that each driving factor had its appropriate range for impacting vegetation growth in the study area.

Different vegetation types may affect the accumulation and transformation of soil organic carbon （SOC）, but it is unclear whether the organic carbon fixation is realized by litter input and/or root control of environmental factors and dissolved organic matter （DOM） of soils. In this study, the spatial distribution characteristics of easily oxidizable organic carbon （EOC）, dissolved organic carbon （DOC）, particulate organic carbon （POC）, mineral-bound organic carbon （MAOC）, and their seasonal variations in the surface soil （0-10 cm） were studied in different vegetation zones of the arbor forest （at the upper position）, the mixed forest of arbor and shrub （at the middle position）, and the waterfront vegetation （at the bottom position） in the ecological embankment of Duliujian River, Tianjin, China. The spatial distribution characteristics of soil DOM components and their seasonal changes were also analyzed by combining UV-visible spectroscopy and 3D fluorescence spectroscopy. The results showed that： ① The accumulation of SOC was significantly higher in the waterfront vegetation than in the arbor forest and the mixed forest of arbor and shrub in summer, whereas the opposite was true during the spring season. It was indicated that the root input of the soil was the key driving factor for determining the accumulation of SOC in summer, whereas the input quality of above-ground litters was more important for the sequestration of SOC in spring. ② Differences in DOM fractions explained the fixation and transformation pathways of SOC in different seasons, with humus-derived DOM in spring promoting the transformation of DOC to POC and MAOC and microbial-derived DOM in summer advancing the transfer of EOC to MAOC under the action of microorganisms. ③ Soil physicochemical properties had less direct influences on SOC, which preferentially affected SOC accumulation by regulating the composition as well as the chemical structure of soil DOM. ④ The structural equation modeling indicated that water content （MC） and total phosphorus （TP） were directly involved in SOC transport and transformation, whereas ammonium nitrogen （NH₄⁺-N）, nitrate nitrogen （NO₃^--N）, electrical conductivity （EC）, available phosphorus （AP）, pH, K⁺, and Na⁺ indirectly affected SOC accumulation mediated by DOM from humus and microbial sources. In summary, the present study elucidated that the trade-off mechanisms affecting SOC sequestration in the critical functional zone along the land-river ecotone, and the results can provide theoretical support for further exploring the constructive methods of ecological corridors and the pathways of carbon sequestration and sink enhancement in the "watershed-estuary-offshore" system of the coastal rivers.

By collecting the atmospheric precipitation, surface water, and groundwater in the Inner Mongolia section of the Yellow River Basin in July 2021 （wet season）, October （normal season）, and April 2022 （dry season）, stable isotope technology was used to analyze the temporal and spatial changes in hydrogen and oxygen stable isotopes in the "three rivers" of the basin, and the MixSIAR mixing model was used to reveal the water body transformation relationship. The results showed that the mean difference in the groundwater isotope was small in the abundance period, flat period, and dry period in the Mongolia section of the Yellow River Basin. The groundwater regeneration was slow, the retention time was long, the seasonal variation was not obvious, and the δD value of surface water was higher in the abundance period than in the normal period and dry period. According to the δ¹⁸O and δD diagrams, the slope and intercept of surface water lines in the three periods were smaller than those of local precipitation lines, and surface water was affected by evaporative fractionation after receiving precipitation recharge. The δD values of surface water on the north bank of the Yellow River showed a trend of first increasing and then decreasing from upstream to downstream, while the δD values of surface water on the south bank of the Yellow River showed a trend of gradually decreasing from upstream to downstream. The recharge contribution of groundwater in surface water in the high-water period accounted for 2.9%, precipitation accounted for 97.1%, surface water accounted for 5.0%, atmospheric precipitation accounted for 95.0%, surface water accounted for 56.6%, and precipitation accounted for 43.4%, and the recharge contributions of precipitation and surface water to groundwater in the high water period were 47.6% and 52.4%, respectively. Those in the normal period were 30.7% and 69.3%, and those in the dry period were 37.8% and 62.2%, respectively. Atmospheric precipitation was the main replenishment source of surface water, showing that the replenishment ratio in the wet season was larger than that in the normal season and dry season, which was closely related to the total precipitation and its distribution in each period. Surface water was the main replenishment source of groundwater, showing that dry season > normal season > wet season.

The application of exogenous substances has important effects on soil greenhouse gas emissions and phytoremediation of soil contaminated by heavy metals. Pennisetum americanum×Pennisetum purpureum and Helianthus annuus were used as remediation plants in this study. The effects of different exogenous substances on phytoremediation and greenhouse gas emissions of heavy metal-contaminated soil were studied. The results showed that the application of exogenous substances had little effect on the pH value of P. americanum×P. purpureum soil but significantly reduced the pH value of H. annuus soil compared with that of the background soil. The application of potassium fertilizer （KCl） increased the biomass of plants, enhanced the activities of superoxide dismutase （SOD） and peroxidase （CAT）, and improved the stress resistance of H. annuus. The application of gibberellin （GA₃） and indole butyric acid （IBA） decreased the antioxidant enzyme activity and the content of malondialdehyde （MDA） and alleviated the stress of heavy metals in H. annuus. The KCl and EDDS treatments affected the accumulation of Cd and Pb in plants, respectively. The application of KCl significantly increased the accumulation of Cd in P. americanum×P. purpureum and H. annuus and the accumulation of Cd in P. americanum×P. purpureum roots, and the application of EDDS significantly increased the accumulation of Pb in H. annuus shoots and H. annuus roots. Compared with those in the CK treatment, the application of KCl and EDDS could reduce the cumulative CO₂ emissions in soil, which were 20.4% and 5.0% in P. americanum×P. purpureum planting soil and 15.8% and 45.9% in H. annuus planting soil, respectively. However, the application of GA₃ and IBA could increase the cumulative CO₂ emissions. Exogenous substance treatment increased the cumulative N₂O emissions of P. americanum×P. purpureum soil but decreased the cumulative N₂O emissions of H. annuus soil to different degrees. Compared with those in the CK treatment, the application of KCl and GA₃ significantly reduced the cumulative N₂O emissions of H. annuus by 40.5% and 43.5%, respectively. The application of EDDS and IBA reduced the cumulative N₂O emissions by 20.1% and 28.4%, respectively. In conclusion, the application of GA₃ and IBA alleviated the heavy metal stress of H. annuus, and the KCl and EDDS treatments enhanced phytoremediation efficiency and reduced soil greenhouse gas emissions to varying degrees.