The Three Gorges Dam’s construction and industrial transfer have resulted in a new air pollution pattern with the potential to threaten the reservoir eco-environment. To assess the impact of socioeconomic factors on the pattern of air quality vairation and economical risks, concentrations of SO₂, NO₂, and PM₁₀, industry genres, and meteorological conditions were selected in the Three Gorges Reservoir of Chongqing (TGRC) during 2006–2015. Results showed that air quality had improved to some extent, but atmospheric NO₂ showed an increased trend during 2011–2015. Spatially, higher atmospheric NO₂ extended to the surrounding area. The primary industry, especially for agriculture, had shown to be responsible for the remarkable increase of atmospheric NO₂ (p < 0.01) due to the direct burning of agricultural straws and the emission of livestock breeding. The improvement of regional industrial structure and industrialization benefited air pollutant reductions, but construction industries had inhibited the improvement of regional air quality. In the tertiary industry, the cargo industry at ports had significantly decreased atmospheric NO₂ as a result of eliminating the obsoleted small ships. Contrarily, the highway transportation had brought more air pollutants. The relative humidity was shown to be the main meteorological factor, which had an extremely remarkable relation with atmospheric SO₂ (p < 0.01) and a significant correlation with atmospheric NO₂ (p < 0.05), respectively. In the future, the development of agriculture and livestock breeding would make regional air quality improvement difficult, and atmospheric SO₂, NO₂, and PM₁₀ deposition would aggravate regional soil and water acidification and reactivate heavy metal in soil and sediment, further to pose a high level of ecological risk in the TGRC and other countries with reservoirs in the world.

Without an engineering risk assessment for emergency disposal in response to sudden water pollution incidents, responders are prone to be challenged during emergency decision making. To address this gap, the concept and framework of emergency disposal engineering risks are reported in this paper. The proposed risk index system covers three stages consistent with the progress of an emergency disposal project. Fuzzy fault tree analysis (FFTA), a logical and diagrammatic method, was developed to evaluate the potential failure during the process of emergency disposal. The probability of basic events and their combination, which caused the failure of an emergency disposal project, were calculated based on the case of an emergency disposal project of an aniline pollution incident in the Zhuozhang River, Changzhi, China, in 2014. The critical events that can cause the occurrence of a top event (TE) were identified according to their contribution. Finally, advices on how to take measures using limited resources to prevent the failure of a TE are given according to the quantified results of risk magnitude. The proposed approach could be a potential useful safeguard for the implementation of an emergency disposal project during the process of emergency response.

Immune system is critical to protecting human health from toxic substances. Our previously published research had found an important link between polycyclic aromatic hydrocarbons (PAHs) in ambient air and changes at the DNA level in immune cells that led to impaired function of regulatory T (Treg) cells in children living in California, USA. But molecular and cellular pathways of these changes remain unclear. The present study aims to explore whether exposure to PAHs leads to changes in Treg cells functions of children living in Gansu, China, where ambient air pollution levels are much higher than those in California, and to explore potential mechanisms of PAH-induced immunological dysfunctions. Air pollutions in Lanzhou and Lintao, Gansu Province, were measured from December 2015 to June 2016. Healthy children were recruited from both cities and enrolled in this pilot study. Demographic information was collected by questionnaires. Blood samples were collected. Peripheral blood Treg cells were analyzed for Treg cells percentage by flow cytometry. Gene expression of forkhead box transcription factor 3 (Foxp3), transforming growth factor-β (TGF-β), and interleukin 35 (IL35) were examined by reverse transcription-polymerase chain reaction (RT-PCR). The results indicated PAH concentration (as sum of 16 PAHs) in Lintao was over two times higher than that was in Lanzhou (707 vs. 326 ng/m³), whereas PM₂.₅ concentration was comparable in two cities (55.3 in Lintao vs. 65.7 μg/m³ in Lanzhou). Notably, we observed lower gene expressions for Foxp3 (P < 0.05), IL35 (P < 0.05), and TGF-β, in children living in Lintao, suggesting an impairment of Treg cells function potentially associated with higher PAH exposure in Lintao. However, no significant difference was observed in Treg cells % among CD4⁺ T cells between Lanzhou and Lintao groups.

The agricultural waste, date palm leaflets, was carbonized chemically using sulfuric acid treatment. Produced dehydrated carbon (DC) was subjected to surface functionalization using ethylene diamine producing chelating dehydrated carbon (CDC). In the process, ∼80 % of the carboxylic content on DC was converted to amide successfully. DC acts as a cation exchanger because of the high content of carboxylic groups on its surface showing acidic nature. However, CDC possesses amine and amide groups showing basic nature. Both amine and amide groups are capable of chelating Zn²⁺ at high pH; however, at low pH, the amine group becomes protonated acting as anion exchanger. Sorption of Zn²⁺ and SO₄ ²⁻ was investigated in terms of contact time, initial pH, concentration, and carbon reuse. Zn²⁺ shows maximum sorption at initial pH 5; however, maximum sorption of SO₄ ²⁻ takes place at initial pH 2. Kinetic and equilibrium studies were carried out at initial 5 and 2 for Zn²⁺and SO₄ ²⁻, respectively. Sorption kinetics data follow well the pseudo second-order model. The equilibrium sorption data follow the Langmuir isotherm more than the Freundlich isotherm. CDC shows better sorption performance for Zn²⁺ and SO₄ ²⁻ than DC. DC and CDC show combined equimolar removal of both Zn²⁺ and SO₄ ²⁻ at initial pH 2.3 and 2.6, respectively, with efficient recycle properties. Combined removal of Zn²⁺ and SO₄ ²⁻ from spiked municipal wastewater shows less uptake on both carbons than from deionized water.

The present study investigated the comprehensive chemical composition [organic carbon (OC), elemental carbon (EC), water-soluble inorganic ionic components (WSICs), and major & trace elements] of particulate matter (PM₂.₅) and scrutinized their emission sources for urban region of Delhi. The 135 PM₂.₅ samples were collected from January 2013 to December 2014 and analyzed for chemical constituents for source apportionment study. The average concentration of PM₂.₅ was recorded as 121.9 ± 93.2 μg m⁻³ (range 25.1–429.8 μg m⁻³), whereas the total concentration of trace elements (Na, Ca, Mg, Al, S, Cl, K, Cr, Si, Ti, As, Br, Pb, Fe, Zn, and Mn) was accounted for ∼17% of PM₂.₅. Strong seasonal variation was observed in PM₂.₅ mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons. The chemical composition of the PM₂.₅ was reconstructed using IMPROVE equation, which was observed to be in good agreement with the gravimetric mass. Source apportionment of PM₂.₅ was carried out using the following three different receptor models: principal component analysis with absolute principal component scores (PCA/APCS), which identified five major sources; UNMIX which identified four major sources; and positive matrix factorization (PMF), which explored seven major sources. The applied models were able to identify the major sources contributing to the PM₂.₅ and re-confirmed that secondary aerosols (SAs), soil/road dust (SD), vehicular emissions (VEs), biomass burning (BB), fossil fuel combustion (FFC), and industrial emission (IE) were dominant contributors to PM₂.₅ in Delhi. The influences of local and regional sources were also explored using 5-day backward air mass trajectory analysis, cluster analysis, and potential source contribution function (PSCF). Cluster and PSCF results indicated that local as well as long-transported PM₂.₅ from the north-west India and Pakistan were mostly pertinent.

Rapid economic development and increasing population in China have exerted tremendous pressures on the coastal ecosystems. In addition to land-based pollutants and reclamation, fast expansion of large-scale intensive mariculture activities has also brought about additional effects. So far, the ecological impact of rapid mariculture development and its large-scale operations has not drawn enough attention. In this paper, the rapid development of mariculture in China is reviewed, China’s effort in the application of ecological mariculture is examined, and the vulnerability of marine ecosystem to mariculture impact is evaluated through a number of examples. Removal or reduced large and forage fish, due to both habitat loss to reclamation/mariculture and overfishing for food or fishmeal, may have far-reaching effects on the coastal and shelf ecosystems in the long run. Large-scale intensive mariculture operations carry with them undesirable biological and biochemical characteristics, which may have consequences on natural ecosystems beyond normally perceived spatial and temporal boundaries. As our understanding of possible impacts of large-scale intensive mariculture is lagging far behind its development, much research is urgently needed.

Sediment microbial fuel cells (SMFCs) are devices that generate electrical energy through sediments rich in organic matter (OM). The present study assessed the potential of sediments collected at two sites in Yucatan, Mexico, (the swamp of Progreso port and Yucalpetén dock) to be used in these electrochemical devices. Sediments were collected during the rainy and winter seasons and were monitored in the SMFC for 120 days through electrochemical and physicochemical characterization. OM removal in the SMFC ranged from 8.1–18.01%, generating a maximum current density of 232.46 mA/cm² and power density of 95.85 mW/cm². SUVA analysis indicated that with a young soil, the ratio E4/E6 presented evidence directly related to the degradation of aromatic and aliphatic compound formation, implying humification and, therefore, sediment enrichment.

This study evaluated the toxicity potential of ZnO and TiO₂ nanoparticles under pre-UV-A irradiation and visible light condition on Artemia salina. The nanoparticle suspension was prepared in seawater medium and exposed under pre-UV-A (0.23 mW/cm²) and visible light (0.18 mW/cm²) conditions. The aggregation profiles of both nanoparticles (NPs) and dissolution of ZnO NPs under both irradiation conditions at various kinetic intervals (1, 24, 48 h) were studied. The 48-h LC₅₀ values were found to be 27.62 and 71.63 mg/L for ZnO NPs and 117 and 120.9 mg/L for TiO₂ NPs under pre-UV-A and visible light conditions. ZnO NPs were found to be more toxic to A. salina as compared to TiO₂ NPs. The enhanced toxicity was observed under pre-UV-A-irradiated ZnO NPs, signifying its phototoxicity. Accumulation of ZnO and TiO₂ NPs into A. salina depends on the concentration of particles and type irradiations. Elimination of accumulated nanoparticles was also evident under both irradiation conditions. Other than ZnO NPs, the dissolved Zn²⁺ also had a significant effect on toxicity and accumulation in A. salina. Increased catalase (CAT) activity in A. salina indicates the generation of oxidative stress due to NP interaction. Thus, this study provides an understanding of the toxicity of photoreactive ZnO and TiO₂ NPs as related to the effects of pre-UV-A and visible light irradiation.

Heavy metal concentrations in soil, wheat, and scalp hair exposed to Beijing sewage discharge channel sewage irrigation area (BSIA) in Tianjin were studied to evaluate the influence of sewage irrigation. Results showed that the continuous application of wastewater has led to an accumulation of heavy metals in the soil, with 55.2 and 8.62% of soil samples accumulating Cd and Zn, respectively, at concentrations exceeding the permissible limits in China. Concentrations of heavy metals in wheat grain from BSIA were higher than these from the clean water irrigation area by 63.2% for Cd, 3.8% for Cu, 100% for Pb, 6.6% for Zn, and 326.7% for Cr. The heavy metal bioaccumulation factor (BAF) of wheat/soil in BSIA showed the following order: Zn > Cd > Cu > Pb > Cr. Interestingly, these accumulation of heavy metals in soil after sewage irrigation could increase the migration ability of heavy metals (particularly Zn and Cd) from soil to wheat. Mean concentrations of heavy metals in the hair of residents followed the decreasing trend of Zn > Cu > Pb > Cr > Cd, which were higher than the control area by 110.0% for Cd, 20.0% for Cu, 55.9% for Zn, 36.6% for Pb, and 64.6% for Cr. Concentrations of heavy metals in male human hair in BSIA were higher than those of females. And the concentrations of heavy metals except for Pb in human hair increased with their increasing ages. The heavy metal BAF values of wheat/soil in BSIA showed the trend of Zn (98.0057) > Pb (7.0162) > Cr (5.5788) > Cu (5.4853) > Cd (3.5584); heavy metals had obvious biological amplification from wheat to human hair. These results indicated that local population health was potentially exposed to the heavy metal risk via wheat consumption.

In the current study, we used micromodel experiments to study three-phase fluid flow in porous media. In contrast to previous studies, we simultaneously observed and measured pore-scale fluid behavior and three-phase constitutive relationships with digital image acquisition/analysis, fluid pressure control, and permeability assays. Our results showed that the fluid layers significantly influenced pore-scale, three-phase fluid displacement as well as water relative permeability. At low water saturation, water relative permeability not only depended on water saturation but also on the distributions of air and diesel. The results also indicate that the relative permeability–saturation model proposed by Parker et al. (1987) could not completely describe the experimental data from our three-phase flow experiments because these models ignore the effects of phase distribution. A simple bundle-of-tubes model shows that the water relative permeability was proportional to the number of apparently continuous water paths before the critical stage in which no apparently continuous water flow path could be found. Our findings constitute additional information about the essential constitutive relationships involved in both the understanding and the modeling of three-phase flows in porous media.