Suchergebnisse

AbstractThe issue of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has created enormous threat to global health. In an effort to contain the spread of COVID-19, a huge amount of disinfectants and antibiotics have been utilized on public health. Accordingly, the concentration of disinfectants and antibiotics is increasing rapidly in various environments, including wastewater, surface waters, soils and sediments. The aims of this study were to analyze the potential ecological environment impacts of disinfectants and antibiotics by summarizing their utilization, environmental occurrence, distribution and toxicity. The paper highlights the promoting effects of disinfectants and antibiotics on antibiotic resistance genes (ARGs) and even antibiotic resistant bacteria (ARB). The scientific evidences indicate that the high concentration and high dose of disinfectants and antibiotics promote the evolution toward antimicrobial resistance through horizontal gene transformation and vertical gene transformation, which threaten human health. Further concerns should be focused more on the enrichment, bioaccumulation and biomagnification of disinfectants, antibiotics, antibiotic resistance genes (ARGs) and even antibiotic resistant bacteria (ARB) in human bodies.

Abstract
Background
Screen the priority of emerging contaminants (ECs) from sediments is essential for risk assessment to aquatic environment and human health. Currently, priority approaches mainly focus on contaminant identification, exposure analysis, risk assessment, and hazard properties. However, there is still far from the reality due to, for instance, limitations on lack of occurrence data and uncertainty analysis. In this study, the multi-criteria screening method on the basis of hazard potential (HP) and exposure potential (EP) integrating with uncertainty analysis was developed for prioritization of 185 ECs, which have been reported to be widely found in the Yangtze River sediment. The HP based on the ecological risk and human health, and the EP according to the occurrence were both quantitatively analyzed. The priority index of these 185 chemicals was the product of the normalized HP and the normalized EP.

Results
According to the priority ranking scheme, 20 chemicals were identified as the top-priority, and 58 compounds as high-priority, respectively. After uncertainty scoring for each chemical based on data availability, there were 7 compounds (5 pesticides and 2 PFASs) recommended as the major priority ECs. In addition, the current study also emphasized that necessary for further studying some ECs, such as PFAS alternatives, as the data limitation may lead to reduce accurate prioritization.

Conclusions
Overall, this study provides an efficient approach for screening priority ECs, which is useful for river ecosystem health management.

Abstract
Background
While a dam is constructed to adjust and store water resources, it has negative impacts on biodiversity of the corresponding ecosystems. In particular, the dam regulation induces water-level fluctuations (WLFs), resulting in remarkable effects on the riparian vegetation succession of the drawdown zone ecosystem. These riparian plant responses play important roles in the biodiversity conservation. However, in-depth investigative adequate studies are still lacking. The objective of this study was to assess the community assembly under the anti-seasonal WLFs of China's Three Gorges Reservoir (TGR). To analyze the WLFs' impacts on plant community, the drawdown zone of the TGR was divided into four sub-zones (zone I, II, III, and IV) according to the inundation periods. The community biomass, height, total coverage, and species diversity in each sub-zone were surveyed. To detect the response of individual plant to the WLFs, dominant plants of Echinochloa crusgalli, Setaria viridis, Bidens pilosa, and Xanthium sibiricum were selected as targeted species to compare the plant's morphological and physiological traits between non-flooded area and the moderately inundated area.

Results
The peaks of community biomass (1859.62 ± 663.77 g), total coverage (103.93 ± 11.81%), and diversity indexes were found in zone II that experienced 90 days of inundation. Community height and total coverage were both significantly negatively correlated to the inundated gradients. Generalized linear models and quadratic regression analyses revealed that community biomass, height, and total coverage were strongly related to the inundated gradients, implying that the inundation is the major factor contributing to the variation of the riparian vegetation patterns. The values of morphological traits (plant height and biomass) in the zone II were higher than those in the non-flooded zone, and were significantly positively correlated with physiological traits.

Conclusions
Community structure, diversity, and functional traits analysis indicated that the drawdown zone referencing to the 90-day inundation was suitable for the plant community establishment. Results on plant functional traits suggest the adaption of riparian plants to the TGR hydrological regime. However, further investigative studies with more plant species are necessary to elucidate their adaptation mechanisms.

Abstract
Background
Urbanization process around the world has not only changed the patterns of land use, but also fragmented the habitat, resulting in significantly biodiversity loss. Urban rivers, serve as one of the natural corridors in urban ecosystems, are of importance for urban ecosystem stability. However, few studies have been done to explore the relationship between vegetation and pollinators in urban river segments. In this study, two urban streams in the city of Chongqing were selected as the study area, riparian vegetation, butterflies and bees were investigated along all four seasons of a year to illustrate the spatial and temporal distribution patterns. Simultaneously, the ecological functions of the river corridor were analyzed.

Result
In this study, 109 plant species belonging to 95 genera of 39 families were recorded; the number of sampled species for butterflies and bees were 12 and 13, respectively. The temporal and spatial patterns of species diversity among vegetation, butterfly, and bee are different, but the trends of variation among them are similar between the two streams. Bees were found to be more closely correlated with native flowering plants in riparian zone, rather than with cultivated riparian vegetation.

Conclusions
The native riparian vegetation in urban rivers plays an important role in urban biodiversity conservation by serving as a corridor. This study provides data supporting the protection of the remaining natural patches and restoration of damaged habitats in the city. The survey has accumulated data on native riparian vegetation and pollinators in urban rivers.

Abstract
Background
The gaps between estrogenic effect and its effect-active compounds exist frequently due to a large number of compounds that have been reported to induce this effect and the occurrence of pollutants in environments as mixtures. Therefore, identifying the estrogen-active compounds is of importance for environmental management and pollution treatment. In the current study, the effect-directed analysis (EDA) and non-targeted screening (NTS) were integrated to identify the estrogen-active compounds in soils of the rural area with different socioeconomic types (industrial, farming and plantation village) in Northeast China.

Results
The cytotoxicity results indicated that the industrial and farming villages showed cytotoxic effects. The detection rates of estrogenic effects for samples of winter and summer were 100% and 87%, respectively. Of which, the effects were found to be stronger in summer than in winter, with significant difference observed from the farming village (0.1–11.3 EEQ μg/kg dry weight). A total of 159 chemicals were detected by NTS. By integrating EDA, triphenyl phosphate (TPhP) and indole were successfully identified from a raw sample and its fraction, explaining up to 19.31% of the estrogen activity.

Conclusions
The present study demonstrates that the successful identification of seven estrogen-active compounds in rural areas of northeastern China can be achieved through the combination of effect-directed analysis (EDA) and non-targeted screening (NTS). This finding is beneficial for risk monitoring and pollution management.

Abstract
Background
Flood events increase the risk of sediment erosion and hence the release of particle-bound pollutants besides other processes that can be observed during such events like transportation, lateral distribution and other. Macropollutants, such as acids, salts, nutrients, and natural organic matter, are usually diluted by flooding, while the effect of floods on micropollutants is still unclear. To fill this gap, Qingshui Stream, a tributary of the Jialing River in the city of Chongqing that suffered 75,000 m3·s−1 flood in August 2020 was selected in the current study to clarify effects of flood-induced pollution transportation. 14 surface water samples and 14 sediment samples were collected to analyze the occurrence of micropollutants (including 21 organochlorine pesticides (OCPs), 34 organophosphorus pesticides (OPPs) and 3 estrogenic compounds) before, during and after the flood. Finally, the environmental risks were evaluated by risk quotient (RQ).

Results
The concentrations of total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD) in the surface water decreased from upstream to downstream, and the amounts were diluted by flooding from 0.08 to 0.05 mg·L−1 for TP, from 0.06 to 0.02 mg·L−1 for TN and from 132 to 27 mg·L−1 for COD, respectively. The concentration of estrogenic compound was up to 90 ng·g−1, which was reduced to be lower than the limit of detection during flood. Alpha-endosulfan, delta-BHC, mirex, dichlorvos, phosdrin, thionazine, tetraethyl pyrophosphate, diazinon, methyl parathion, malathion, chlorpyrifos, famphur, and EPN were diluted by flooding, i.e., the concentration of delta-BHC reduced from 6.67 to 0.09 ng·g−1; whereas, pp'-DDD, heptachlor epoxide, o,o,o-triethylphosphorothioate, dimethoate, rabon and fensulfothion were enriched after the flood. The environmental risk was observed to be mainly arise from the presence of OPPs, which increased after flooding. The RQ values of OPPs and OCPs increased after the flood, and the potential environmental risk of OPPs accounted for the majority portion of the risk.

Conclusions
The concentrations of macropollutants in surface water and sediments, and 14 micropollutants in sediments were diluted, while pesticides such as pp′-DDD, heptachlor epoxide, o,o,o-triethylphosphorothioate, dimethoate, rabon and fensulfothion were enriched after the flood. These results suggested management on urban river should focus on potential risk of OPPs. The current study therefore could provide scientific evidence and regulatory reference for urban river ecosystem protection.

Abstract
Background
In rural areas, the surface water quality is seriously threatened by pollution from agriculture, breeding, industrial and tourism activities. Even though many strategies and programs were launched for rural environment management, it is challenging to tackle the serious surface water pollution in villages. Since pollution status varies with the type of villages, there is no single parameter that defines environment quality completely. Until recently, most of rural surface water quality monitoring programs focus only on the conventional parameters, while can these conventional parameters reflect comprehensive status of water quality? To study how much the conventional parameters contribute to biological toxicity of surface water in villages, the in situ parameters of pH, DO, EC, ORP, laboratorial parameters of COD, TN, NO3−-N, NO2−-N, NH4+-N, TP, and PO43−-P and acute toxicity were analyzed for the surface water samples those were collected from six types of villages, named breeding, agricultural, handicraft, industrial, agricultural and breeding, and tourism. The correlation analysis was applied to establish the linkages and contributions of each parameter.

Results
The results showed that all detected surface waters were alkaline, and the concentration of TN and most of COD concentrations in all six types of villages were higher than the Class V limits specified in environmental quality standards for surface water (GB3838-2002). Pearson's correlation analysis showed that significantly positive correlations were found for the acute toxicity effects and laboratorial parameters of NO2−-N, NH4+-N and PO43−-P in agricultural villages, and negative correlations were found for the acute toxicity effects and laboratorial parameters of TN and NO3−-N. No significant correlation was observed in breeding villages and industrial villages.

Conclusion
The problems of nitrogen pollution and aerobic pollution are still serious in villages, and more attention should be paid in further rural environment management. NH4+-N could contribute to the acute toxicity of surface water in the most of investigated villages, while no significant correlation was observed between acute toxicity and conventional parameters in industrial villages and tourism villages. Environmental monitoring programs focusing just on the classical conventional parameters are far from sufficient, since the main toxic contributors are quite different in diverse villages. The outcomes of the present study contribute to demonstrate the performance and usefulness of bioanalytical techniques for water quality assessment.

Abstract

Background
Urban river pollution risks to environments and human health are emerging as a serious concern worldwide. With the aim to achieve the health of urban river ecosystem, numerous monitoring programs have been implemented to investigate the spectral characteristics of contamination. While due to the complexity of aquatic pollutants, the linkages between harmful effects and the spectral characteristics of contamination are still a major challenge for capturing main threats to urban aquatic environments. To establish these linkages, surface water (SW), sediment pore water (SDPW), and riparian soil pore water (SPW) were collected from five sites of the seriously polluted Qingshui Stream, China. The water-dissolved organic carbon (DOC), total nitrogen (TN), total phosphate (TP), fluorescence excitation–emission matrix, and specific ultraviolet absorbance were applied to analyze the spectral characteristics of urban river contamination. The Photobacterium phosphorem 502 was used to test the acute toxicity of the samples. Finally, the correlations between acute toxicity and concentrations of DOC, TN, TP, and the spectral characteristics were explored.


Results
The concentrations of DOC, TN, and TP in various samples amounted from 11.41 ± 2.31 to 3844.67 ± 87.80 mg/L, from 1.96 ± 0.06 to 906.23 ± 26.01 mg/L and from 0.06 ± 0.01 to 101.00 ± 8.29 mg/L, respectively. The florescence index (FI) amounted from 1.54 to 3.14, the biological index (BIX) were between 0.94 and 1.57. The distribution patterns of specific ultraviolet absorbance at 254 nm (SUVA254) showed that the highest aromaticity and hydrophobicity were found in SDPW and the lowest ones were in SW. All samples showed significantly inhibition on luminescent bacteria. Particularly, the highest acute toxicity was found in site 1 with an EC50 value of 6.023-fold dilution for the raw SDPW sample. In addition, the highest fluorescence intensity was also observed from SDPW of site 1.


Conclusions
Tryptophan-like and protein-like substances could be important DOC fractions contributing remarkably to the acute toxicity in the seriously polluted river. In addition, the significant reduction on acute toxicity was found with the treatment of surface water flow constructed wetland, revealing that constructed wetland could be an effective approach for toxicant degradation. These observations are useful for water treatments, and meaningful for urban sustainable development.

AbstractRural development, as one of the biggest challenges facing human beings recently, has attracted widely attention in the world, among which rural environment protection is essential for sustainable development. In response to the call to build "green livable villages", the environmental monitoring and remediation in rural project (EMR-rural project) is launched. EMR-rural (2019 to 2022) is funded by the Ministry of Science and Technology of the People's Republic of China (MOST). The project aims to develop key techniques and devices for contamination classification, risk assessment, pollution sources tracing and environmental remediation with regard to soil, underground and surface water quality in rural area. To this end, a new generation of physical, chemical and biological tools is integrated with intelligent management platform. The project follows a problem-oriented approach by in situ investigation, lab/pilot-scale mechanism exploration and field determination. EMR-rural takes advantage of the access to the applicable techniques and devices to investigate and to restore soil and water pollution in river network areas, mountainous areas as well as cold areas of China.