New insights into the effects of antibiotics and copper on microbial community diversity and carbon source utilization.

Residual antibiotics (ABs) and heavy metals (HMs) are continuously released from soil, reflecting their intensive use and contamination of water and soil, posing an environmental problem of great concern. Relatively few studies exist of the functional diversity of soil microorganisms under the combined action of ABs and HMs. To address this deficiency, BIOLOG ECO microplates and the Integrated Biological Responses version 2 (IBRv2) method were used to comprehensively explore the effects of single and combined actions of copper (Cu) and enrofloxacin (ENR), oxytetracycline (OTC), and sulfadimidine (SM2) on the soil microbial community. The results showed that the high concentration (0.80 mmol/kg) compound group had a significant effect on average well color development (AWCD) and OTC showed a dose-response relationship. The results of IBRv2 analysis showed that the single treatment group of ENR or SM2 had a significant effect on soil microbial communities, and the IBRv2 of E1 was 5.432. Microbes under ENR, SM2, and Cu stress had more types of available carbon sources, and all treatment groups were significantly more enriched with microorganisms having D-mannitol and L-asparagine as carbon sources. This study confirms that the combined effects of ABs and HMs can inhibit or promote the function of soil microbial communities. In addition, this paper will provide new insights into IBRv2 as an effective method to evaluate the impacts of contaminants on soil health.

Key emergency response technologies for abrupt air pollution accidents in China.

Abrupt air pollution accidents can endanger people's health and destroy the local ecological environment. The appropriate emergency response can minimize the harmful effects of accidents and protect people's lives and property. This paper provides an overview of the key emergency response technologies for abrupt air pollution accidents around the globe with emphasis on the major achievements that China has obtained in recent years. With decades of effort, China has made significant progress in emergency monitoring technologies and equipment, source estimation technologies, pollutant dispersion simulation technologies and others. Many effective domestic emergency monitoring instruments (e.g., portable DOAS/FT-IR systems, portable FID/PID systems, portable GC-MS systems, scanning imaging remote sensing systems, and emergency monitoring vehicles) had been developed which can meet the demands for routine emergency response activities. A monitoring layout technique combining air dispersion simulation, fuzzy comprehensive evaluation, and a post-optimality analysis was proposed to identify the optimal monitoring layout scheme under the constraints of limited monitoring resources. Multiple source estimation technologies, including the forward method and the inversion method, have been established and evaluated under various scenarios. Multi-scale dynamic pollution dispersion simulation systems with high temporal and spatial resolution were further developed. A comprehensive emergency response platform integrating database support, source estimation, monitoring schemes, fast monitoring of pollutants, pollution predictions and risk assessment was developed based on the technical idea of "source identification - model simulation - environmental monitoring" dynamic interactive feedback. It is expected that the emergency response capability for abrupt air pollution accidents will gradually improve in China.

Atmospheric environment monitoring technology and equipment in China: A review and outlook.

Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources, chemical mechanisms, and transport processes of air pollution and carbon emissions in China, and for regulatory and control purposes. This study gives an overview of atmospheric environment monitoring technology and equipment in China and summarizes the major achievements obtained in recent years. China has made great progress in the development of atmospheric environment monitoring technology and equipment with decades of effort. The manufacturing level of atmospheric environment monitoring equipment and the quality of products have steadily improved, and a technical & production system that can meet the requirements of routine monitoring activities has been initiated. It is expected that domestic atmospheric environment monitoring technology and equipment will be able to meet future demands for routine monitoring activities in China and provide scientific assistance for addressing air pollution problems.

A coupled framework for estimating pollutant emissions from open burning of specific crop residue: A case study for wheat.

Crop residue open burning is considered to be one of the main sources of pollutant emissions from rural areas. It is necessary to accurately establish an emissions inventory of specific crops which could reflect the specific spatiotemporal distribution characteristics of crop residue burning emissions. However, the information for emission estimation of specific crop in each province and year is seriously data-deficient, resulting in a large uncertainty in the emissions inventory. In this study, taking the open burning of wheat residue as an example, we propose a framework for estimating pollutant emissions for specific crop residue by combining phenological information, land use data, field investigation/statistical data, and fire detection information. The wheat residue open burning proportion (OBP) and the corresponding pollutant emissions were estimated for each province in mainland China from 2003 to 2019. The national average OBP and emissions of wheat crop residue open burning first increased and then decreased during this period, with the peak in 2012. The gridded spatial distribution showed that high-emission areas were mainly concentrated in central-eastern China, and the emission areas gradually shifted from south to north from April to September. The change of daily emissions from large-scale concentrated emissions to small-scale emissions demonstrated that straw open burning prohibition policies were effective in reducing the annual emissions and peak daily emissions. This study provides a promising method for the combination of data from multiple sources to estimate open burning of crop residues. The method can be used to obtain accurate and detailed emissions data to support research into biomass burning and the development of targeted mitigation strategies.

Improving source inversion performance of airborne pollutant emissions by modifying atmospheric dispersion scheme through sensitivity analysis combined with optimization model.

Estimating accurately airborne pollutant emissions source information (source strength and location) is important for achieving effective air pollution management or adequate emergency responses to accidents. Inversion method is one of the useful tools to identify the source parameters. The atmospheric dispersion scheme has been proven to be the key to determining the source inversion performance by influencing the accuracy of the dispersion models. Modifying the atmospheric dispersion scheme is an important potential method to improve the inversion performance, but this has not been studied previously. To fill this gap, a novel approach for parameter sensitivity analysis combined with an optimization method was proposed to improve the source inversion performance by optimizing empirical scheme. The dispersion coefficients σy and σz of the typical BRIGGS scheme under different atmospheric dispersion conditions were optimized and used for air pollutant dispersion and source inversion. The results showed that the prediction performance of the air pollutant concentrations was greatly improved with statistical indices |FB| and NMSE decreased by 0.22 and 2.07, respectively; FAC2 and R increased by 0.10, and 0.08, respectively. For source inversion, the results of the significance analysis suggested that the accuracy in the source strength and location parameter (x0) were both significantly improved by ∼271% (relative deviation reduced from 60.0% to 16.2%) and ∼121% (absolute deviation reduced from 27.6 to 12.5 m). The improvement of source strength inversion accuracy was more significant under unstable atmospheric conditions (stability class A, B, and C); the mean absolute relative deviation was reduced by 97.5%. These results can help to obtain more accurate source information and to provide reliable reference for air pollution managements or emergency response to accidents. This study provides a novel and versatile approach to improve estimation performance of pollutant emission sources and enhances our understanding of source inversion.

Effects of interaction between enrofloxacin and copper on soil enzyme activity and evaluation of comprehensive toxicity.

Antibiotics are detected in association with heavy metals in the soil. However, interactions between antibiotics and heavy metals on soil enzyme activity have yet to been studied thoroughly. In this study, soil enzyme activity (urease, sucrase, phosphatase, and Rubisco) were measured after exposure to soils dosed with copper (Cu) and/or enrofloxacin (ENR) over 28 days. Enzyme responses to ENR only treatments varied, but Cu exhibited a strong negative response from all soil enzymes except Rubisco. An interaction between the effects of the two pollutants on soil enzymes was observed in the combined contamination treatments. Greater comprehensive toxicity to soil enzyme activity was observed in combined treatment groups compared to other groups. We anticipate our studies can provide a scientific theoretical basis for the combined pollution of antibiotics and heavy metals in soil.

Dose and time-dependent response of single and combined artificial contamination of sulfamethazine and copper on soil enzymatic activities.

The widespread contamination of antibiotics and heavy metals results in imbalance in the ecosystem. However, the effect of the interaction between sulfamethazine (SM2) and copper (Cu) on soil enzymatic activities is unclear. Therefore, this study investigated the effect of single and combined artificial contamination of SM2 and Cu (0, 1.6 mmol kg-1 Cu and 0, 0.05, 0.2, 0.8 mmol kg-1 SM2) on soil enzymatic activities (urease, sucrose, phosphatase, and RubisCO). A single application of Cu at a concentration of 1.6 mmol kg-1 inhibited the urease, phosphatase and sucrase activities, while a stimulating effect on RubisCO activity was observed on day 7, 21, and 28 of incubation. The individual application of SM2 at higher concentration exhibited significant inhibition of sucrase, phosphatase, and urease activities while a stimulatory effect on RubisCO activity was observed on day 14 and 21 of incubation. The combined contamination of SM2 and Cu significantly inhibited the activities of urease, sucrase, and phosphatase. The effect of combined contamination of SM2 and Cu on the activity of RubisCO was different. The analysis results of interaction types show that there are synergistic or antagonistic effects between Cu and SM2, and these effects can amplify or reduce the effect of Cu or SM2 on soil enzyme activities. Integrated biological responses version 2 (IBRv2) analysis showed that the combined contamination of Cu and SM2 had a greater inhibitory or stimulatory effect on soil enzyme activities than the single contamination of Cu and SM2, depending upon dose and time.

A framework for investigating the air quality variation characteristics based on the monitoring data: Case study for Beijing during 2013-2016.

In this study, an analysis framework based on the regular monitoring data was proposed for investigating the annual/inter-annual air quality variation and the contributions from different factors (i.e., seasons, pollution periods and airflow directions), through a case study in Beijing from 2013 to 2016. The results showed that the annual mean concentrations (MC) of PM2.5, SO2, NO2 and CO had decreased with annual mean ratios of 7.5%, 28.6%, 4.6% and 15.5% from 2013 to 2016, respectively. Among seasons, the MC in winter contributed the largest fractions (25.8%~46.4%) to the annual MC, and the change of MC in summer contributed most to the inter-annual MC variation (IMCV) of PM2.5 and NO2. For different pollution periods, gradually increase of frequency of S-1 (PM2.5, 0~75 µg/m3) made S-1 become the largest contributor (28.8%) to the MC of PM2.5 in 2016, it had a negative contribution (-13.1%) to the IMCV of PM2.5; obvious decreases of frequencies of heavily polluted and severely polluted dominated (44.7% and 39.5%) the IMCV of PM2.5. For different airflow directions, the MC of pollutants under the south airflow had the most significant decrease (22.5%~62.5%), and those decrease contributed most to the IMCV of PM2.5 (143.3%), SO2 (72.0%), NO2 (55.5%) and CO (190.3%); the west airflow had negative influences to the IMCV of PM2.5, NO2 and CO. The framework is helpful for further analysis and utilization of the large amounts of monitoring data; and the analysis results can provide scientific supports for the formulation or adjustment of further air pollution mitigation policy.