Effluent from wastewater treatment plants (WWTP) is an important source of organophosphate esters (OPEs) in the receiving rivers. In this paper, the concentration and distribution of seven OPEs in the water samples were determined, and the discharge was estimated. The results showed that the total removal rate of Σ₇OPEs in water phase in WWTP was 57.2%. The average concentrations of Σ₇OPEs in influent and effluent of the WWTP during rainy period were 3956.1 ± 1897.3 ng/L and 1461.9 ± 846.3 ng/L, respectively, which were about 4 times larger than those in influent water (978.2 ± 166.5 ng/L) and effluent (418.3 ± 12.0 ng/L) during non-rainy period, indicating that rainfall has a marked impact on the load of OPEs in WWTP and the receiving water. It was estimated that the average daily discharge of Σ₇OPEs in the effluent of WWTP was 157.9 g, and the daily per capita contribution of the population in the area to the OPEs in the influent was 0.414 mg. During the shift of labour-intensive manufacturing from the coastal developed areas to inland regions, OPEs were widely used and produced in Southwest China. The total amount of OPEs emissions and its control should be taken into consideration.

Determining the circularity of a system through a criteria and indicators approach has been the focus of research in many branches of science. In this way, this work aims to review multiple criteria decision-making (MCDM) methods employed for measuring circular economy (CE) indicators and CE aspects at different levels (micro, meso, and macro). For this purpose, a systematic literature review (SLR) was conducted in ISI Web of Science and Scopus databases. Further, the results summarized 22 MCDM techniques, 27 CE aspects, and 36 CE indicators The SLR provides a concept map highlighting the relation of the level of circularity implementation (subdivided into micro-, meso-, and macro-levels) and MCDM techniques and demonstrates the interaction between CE aspects and indicators. The review provides an outline as to how MCDM techniques can solve problems related to CE aspects and marks the relevance in the use of CE indicators to support circularity aspects and to construct criteria in the methodologies applied.

Regional carbon emission paths have an important impact on the realization of China’s carbon emission peak target. Due to the uncertainty of future development model, the change of carbon emissions will also face uncertainty, which will make achieving the peak target challenging. Taking Shandong, Henan, and Guangdong, three of China’s most populous provinces, as examples, this study analyzed the impacts of uncertainties in carbon accounting principles, driving factors, and simulation mechanism on achieving the peak target. The results show that (1) under the baseline scenario, the accounting principles based on primary energy consumption and IPCC sector consumption will make the peaking time of Guangdong be evaluated as 2018 and 2030, respectively, and the simulation based on IPCC sector accounting will advance the peaking time of Shandong by at least 5 years, while Henan will be less affected. (2) When considering the impact of the energy structure, Guangdong and Henan are estimated to peak in 2011 and 2018, while without considering the impact of the energy structure, the peak in the two provinces may be after 2035. Energy structure has no effect on the estimation of peaking time for Shandong. In addition, the k value in the ridge regression method also has no effect on the peaking time for the three provinces; it only affects the simulations of annual carbon emissions. This study also presented the carbon emission trajectory under different scenarios; from the simulation results, environmental regulation measures such as accelerating industrial structure transformation and increasing energy consumption intensity may help to achieve the peak carbon emission target as soon as possible. It also suggests that uncertainty should be included in future carbon assessments to present a more complete carbon emission trajectory.

The site selection process for municipal solid wastes (MSW) plays an important role in environmental impact studies by allowing the use of environmental design criteria in city and country planning. This process also includes the subject of urban planning due to its impact on the economy, ecology, and environmental health of the region. Urban growth is a phenomenon that is difficult to stop or limit in line with environmental, social, and economic changes and development. Therefore, the selection of solid waste landfill is of great importance in terms of ensuring a sustainable urban future. In the study, Landsat 5 and Landsat 8 satellite images, base map, soil, and geology maps were used for the integration of geospatial data. Each layer specified in the map has been formed using the spatial analysis potential of the ArcGIS10.5 software. In these digitized layers, weight scoring was made using the comparison matrix and the final suitability map was produced. All digital layers established in the generated maps were arranged according to the analytical hierarchy method (AHP) and subjected to the simple additive weighting (SAW) method. The results indicated that 13.51% of the total area was suitable for a sanitary landfill. As a result of this study, urban growth, population projection, and domestic solid waste volume of Sanliurfa province were determined. According to the 25-year population projection, the population in 2045 was approximately 4,471,938 people, and the cumulative waste volume was 27,415,627 m³. In addition, as a result of accepting the wastes of three metropolitan districts and seven district municipalities to the sanitary landfill, only “first candidate area” is the most and has been deemed appropriate. Given the ecological and environmental challenges (proximity to the city center, etc.) associated with the existing MSW sanitary landfill facility in Sanliurfa, the results of this study show that the geographic information system (GIS) integrated AHP and SAW method is an effective tool to assist decision makers to properly plan towards achieving a sustainable environment.

The impact of landscape structures on the water environment has attracted great attention recently. Studying the effects of landscape structure on nutrient and heavy metals at different spatial division scales positively affect ecological protection. The Xiangjiang River Basin, with few external disturbances and light pollution, is the research object, and 16 sampling points were set up on the major stream and tributaries of the Xiangjiang River. The water-quality indicators were divided into conventional water quality indicators and heavy metal indicators. Eleven research scales were set up, including circular buffer zones (100 m, 200 m, 300 m, 500 m, and 1000 m) upstream monitoring points, riparian buffer zones (100 m, 200 m, 300 m, 500 m, and 1000 m), and sub-basin scales. The impacts of landscape structures on conventional indicators and heavy metals in water were quantified at different spatial division scales based on methods, such as principal component analysis and redundancy analysis. The results show the following: (1) the land structure of the Xiangjiang River Basin is dominated by forests, grasslands, and croplands, accounting for more than 97%. The difference in land-use structure is the largest in the circular buffer zone. (2) Settlement, croplands, PRD, grasslands, and COHESION were the main landscape structure indexes affecting the nutrient content in the water. Alternatively, ENN_MN, grassland, PD, LPI, and SHEI are the main landscape structure indicators affecting the heavy metal content in water. (3) For the riparian buffer zone and the circular buffer zone, the landscape structure at 300-m scale has the highest interpretation rate for conventional water quality indicators (93.6% and 85.45%, respectively). The landscape structure at 200-m riparian buffer zones has the highest interpretation rate for heavy metal indicators (93.8%), the landscape structure at 1000-m circular buffer zones has the highest interpretation rate for heavy metal indicators (88.65%). (4) The division of riparian buffer zones helps enhance the interpretation ability of landscape structures on the changes in conventional indicators and heavy metals in water. The 300-m and 200-m riparian buffer zones is the key scales affecting conventional indicators (93.6%), and the 200-m riparian buffer zones is the key scales affecting heavy metals indicators (93.8%). (5) The interpretation rate of landscape structures on conventional water quality indicators was higher in the rainy season than in the dry season; furthermore, the interpretation rate of landscape structures on heavy metals in the rainy and dry seasons is not too different. According to different pollution types, using different division methods and buffer scales helps enhance the accuracy of quantitative analysis. The conclusions can provide a scientific basis for water environment protection, landscape optimization, and Xiangjiang River Basin management.

This paper deals with the study on the influence of the effects of iron oxide nanoparticle additives when added to ternary fuel (diesel + mahua methyl ester + pentanol) on the emission, combustion, and performance characteristics of a four stroke, single cylinder, common rail direct injection diesel engine working at a constant speed and varying operating scenarios. Doping is done in various proportions to the nanoparticle additives with the help of a homogenizer and ultrasonicator where the cationic surfactant used is CTAB (cetyl trimethyl ammonium bromide). Iron oxide nanoparticles were used as additives in fuel in the dosages of 40 ppm, 80 ppm, and 120 ppm respectively and TF (ternary fuel) is obtained by mixing 10% pentanol, 20% mahua, and 70% diesel together is used for the experimental study. The experimental study revealed that while using the nanoparticle additives blended ternary fuel (i.e., TF80), the number of harmful pollutants like smoke (5.38%), HC (6.39%), carbon monoxide (10.24%), and NOₓ has reduced to a considerable extent and there was a commendable improvement in the BTE by 8.8%. So, we can summarize that when ternary fuel and nano additives are blended together the combustion and performance of the engine was improved considerably and pollutant emissions were decreased.

Few studies have evaluated the short-term association between hospital admissions and individual exposure to ambient particulate matter (PM₂.₅). Particularly, no studies focused on hospital admissions for chronic obstructive pulmonary disease (COPD) at the individual level. We assessed the short-term effects of PM₂.₅ on hospitalization admissions for COPD in Guangzhou, China, during 2014–2015, based on satellite-derived estimates of ambient PM₂.₅ concentrations at a 1-km resolution near the residential address as individual-level exposure for each patient. Around 40,002 patients with COPD admitted to 110 hospitals were included in this study. A time-stratified case-crossover design with conditional logistic regression models was applied to assess the effects of PM₂.₅ based on a 1-km grid data of aerosol optical depth provided by the National Aeronautics and Space Administration on hospital admissions for COPD. Further, we performed stratified analyses by individual demographic characteristics and season of hospital admission. Around 10 μg/m³ increase in individual-level PM₂.₅ was associated with an increase of 1.6% (95% confidence interval [CI]: 0.6%, 2.7%) in hospitalization for COPD at a lag of 0–5 days. The impact of PM₂.₅ on hospitalization for COPD was greater significantly in males and patients admitted in summer. Our study strengthened the evidence for the adverse effect of PM₂.₅ based on satellite-based individual-level exposure data.

Estuaries in the world are affected by different contamination sources related to urbanisation and port/industrial activities. Identifying the substances responsible for the environmental toxicity in estuaries is challenging due to the multitude of stressors, both natural and anthropogenic. The Toxicity Identification and Evaluation (TIE) is a suitable way of determining causes of toxicity of sediments, but it poses difficulties since its application is labour intensive and time consuming. The aim of this study is to evaluate the diagnosis provided by a TIE based on microscale embryotoxicity tests with interstitial water (IW) to identify toxicants in estuarine sediments affected by multiple stressors. TIE showed toxicity due to different combinations of metals, apolar organic compounds, ammonia and sulphides, depending on the contamination source closest to the sampling station. The microscale TIE was able to discern different toxicants on sites subject to different contamination sources. There is good agreement between the results indicated in the TIE and the chemical analyses in whole sediment, although there are some disagreements, either due to the sensitivity of the test used, or due to the particularities of the use of interstitial water to assess the sediment toxicity. The improvement of TIE methods focused on identifying toxicants in multiple-stressed estuarine areas are crucial to discern contamination sources and subsidise management strategies.

The Weihe River Basin (WRB), the largest tributary of the Yellow River Basin (YRB), is located in the northwest of China. As the “mother river” of the Guanzhong Plain, it plays an important role in the development of Guanzhong City Group. Based on pH, electric conductivity (EC), total dissolved solids (TDS), and major ionic concentrations of 227 samples collected from the main stream (MS), northern tributaries (NT), and southern tributaries (ST) of the WRB, we explored spatial differential characteristics of hydrochemistry and their controlling factors, solute sources, and water quality of surface water. The results revealed mildly alkaline pH and much higher TDS values than the global average with mean values of 7.9 and 1037.7 mg L⁻¹, respectively. Except NO₃⁻, the concentrations of major ions in the MS and NT were higher than those of the ST, with similar spatial distribution patterns of Ca²⁺, Na⁺, Mg²⁺, SO₄²⁻, and Cl⁻. Na⁺ and SO₄²⁻ were the most dominant cation and anion in the MS and NT controlled by both rock weathering and evaporation-crystallization processes. Ca²⁺ and HCO₃⁻ were the most dominant cation and anion in the ST mainly controlled by rock weathering process. Evaporite dissolution contributed the most to dissolved solutes in the MS and NT, while carbonate weathering dominated dissolved solutes in the ST. These findings were confirmed by the results of correlation matrix, principal component analysis (PCA), stoichiometric plots, and different water types identified as Na-SO₄·Cl in the MS and NT, and Ca-HCO₃ in the ST. Atmospheric and anthropogenic inputs had a minor effect on the surface water chemistry. However, human activities could not be ignored in the ST accounting for 10.9% of the total dissolved solutes, mainly because of the fertilizer application. And the surface water of the ST was more suitable for irrigation and drinking purposes than that of the MS and NT. Knowledge of our findings could contribute new insights to the solute geochemistry and sustainable management of water resources in the lithologically distinct segments of the WRB and other similar areas.

Synergistic effect of biochar and microbes in soil enhances performance of plants. Hazardous tannery solid waste can be reduced by one-third in volume by conversion to biochar. A greenhouse trial was set up with soil having different doses of metal resistant microbe-impregnated biochar (MIBC) prepared from tannery solid waste. Consortia of autochthonous strains of Trichoderma and Bacillus were inoculated on BC and the behavior and fate of metals were evaluated for their bioavailability to sunflower. Sunflower was grown in pots for 80 days having six different amendments of tannery solid waste biochar (0–10% w/w) with and without Trichoderma and Bacillus consortia and its morphological and biochemical attributes as well as metal uptake were observed. The results illustrated that application of BC at 2% rate without inoculation increased the shoot length and dry biomass by 19.8% and 77.4%, respectively, while plant growth and performance were reduced at higher amendments of BC. However, application of MIBC with Trichoderma or/and Bacillus consortium significantly improved the plant attributes at all levels of amendment. The results indicated that MIBC having Trichoderma and Bacillus consortia at 10% rate increased shoot length and dry biomass by 65.3% and 516% compared to control without BC. Application of BC without inoculation reduced the uptake of Cu, Fe, and Ni and increased the mobilization of all other metals for uptake in sunflower. Mobilization and uptake of Cd, Cr, Cu, Ni, Pb, and Zn decreased with MIBC having Trichoderma and Bacillus consortia whereas that of Fe and Mg were noted. A considerable decrease in proline and total phenolic content was demonstrated by MIBC-grown sunflower. The data of metal fractionation in BC also supported the above findings. Therefore, MIBC can be used as a promising option for enhancing growth performance and ensuring the physiological safety of sunflower as an energy crop.