To investigate the chemical composition, size distribution, and mixing state of aerosol particles on heavy pollution days, single-particle aerosol mass spectrometry was conducted during 9–26 October 2015 in Xi’an, China. The measured particles were classified into six major categories: biomass burning (BB) particles, K-secondary particles, elemental carbon (EC)–related particles, metal-containing particles, dust, and organic carbon (OC) particles. BB and EC-related particles were the dominant types during the study period and mainly originated from biomass burning, vehicle emissions, and coal combustion. According to the ambient air quality index, two typical episodes were defined: clean days (CDs) and polluted days (PDs). Accumulation of BB particles and EC-related particles was the main reason for the pollution in Xi’an. Most types of particle size were larger on PDs than CDs. Each particle type was mixed with secondary species to different degrees on CDs and PDs, indicating that atmospheric aging occurred. The mixing state results demonstrated that the primary tracers were oxidized or vanished and that the amount of secondary species was increased on PDs. This study provides valuable information and a dataset to help control air pollution in the urban areas of Xi’an. Graphical abstract

Energy state and environmental impacts of production systems are of main criteria to reach sustainability. In the present research, ostrich was compared with a broiler production system based on the criteria. The required data was gathered in Boukan Township, West Azerbaijan, Iran, by a questioner method. The total input energy in ostrich and broiler systems was calculated as 150,419.81 MJ (1 ton of bird year)⁻¹ and 344,579.58 MJ (1 ton of bird year)⁻¹, respectively. Diesel fuel and feed (41.39% and 36.95%, respectively) in broiler and electricity (45.87%) in the ostrich production system had the highest energy shares. Eleven impact categories were estimated by SimaPro software in the studied systems. Except for human toxicity, fresh water aquatic ecotoxicity, and terrestrial ecotoxicity, the amounts of other environmental impacts in the ostrich production system were lower than those of the poultry production system. The amount of global warming indicator for the production of 1 ton of broiler chicken was 17,400 kg CO₂ eq year⁻¹ that was equal to 4350 kg CO₂ eq period⁻¹. This value was obtained as 1.68 × 10⁴ kg CO₂ eq year⁻¹ for the production of ostrich meat. In both production systems, feed was the main factor responsible for almost all studied environmental impacts.

This paper complements existing literature by assessing the conditional relationship between renewable energy and environmental quality in a sample of 40 African countries for the period 2002 to 2017. The empirical evidence is based on fixed effects regressions and quantile fixed effects regressions. The findings from both estimation techniques show that renewable energy consistently decreases carbon dioxide (CO₂) emissions. Moreover, the negative effect is a decreasing function of CO₂ emissions or the negative effect of renewable energy on CO₂ emissions decreases with increasing levels of CO₂ emissions. In other words, countries with higher levels of CO₂ emissions consistently experience a less negative effect compared with their counterparts with lower levels of CO₂ emissions. Policy implications are discussed.

Selective removal of trace arsenic is crucial for obtaining safe drinking water. Here, the selective adsorptive performance of arsenate (As(V)) on a hybrid ZMAE (nanoscale zirconium molybdate embedded a macroporous anion exchange resin) was examined. It was found that the As(V) adsorption efficiency of ZMAE was almost retained in the presence of competing ions (NO₃⁻ or SO₄²⁻) up an [SO₄²⁻]/[As] or [NO₃⁻]/[As] ratio of 150/1, whereas that of bare AE (anion exchange resin) was negligible for [SO₄]/[As] over 15/1. In addition, the As(V) maximum adsorption capacity of ZMAE was found to be 41.2 mg/g, which is in contrast with the negligible adsorption of bare AE under sulfate-rich condition. The enhanced arsenate selectivity of ZMAE can be attributed to the excellent selectivity of ZM NPs (zirconium molybdate nanoparticles), which contributed up to 45% of the adsorption capacity of ZMAE. The behavior of ZMAE towards arsenate was compared with that towards phosphate showing similar adsorption performances between them, which indicates the similar affinity of ZMAE towards arsenate and phosphate. Finally, ZMAE examined for fixed-bed column adsorption for As(V) removal from synthetic As(V) water was effective for up to 5100 BVs, treating As(V) from 0.1 mg/L to below 0.01 mg/L (meeting the WHO guidelines).

From 2014 to 2016, individuals of the principal non-target arthropod (NTA) species in a field of Bt maize expressing the Cry1Ac protein (Bt38) were compared to those in a control field of the corresponding non-transformed near isoline (Z58). For all 3 years, the population dynamics and biodiversity of NTAs were analyzed to determine if any differences might be attributable to the genetically modified (GM) maize being evaluated. The main NTAs in these fields were Aphidoidea, Pentatomidae,Araneae, and Coccinellidae. Temporal variation in NTA diversity across sample dates within a year showed no significant differences between the Bt maize and the non-Bt maize field in the total number of individuals of the dominant arthropod species per 25 plants, the Shannon index (H), Pielou index (J), Simpson index (D), and Bray-Curtis index. The cultivation of Bt corn failed to show any detrimental evidence on individuals, H, J, D, and Bray-Curtis index of NTAs, and these parameters were identical in Bt and non-Bt corn plots. These results provide further evidence of the lack of ecological impact of GM maize.

As an important environmental regulation tool, does the environmental information disclosure have the pollution haven effect and adversely affect Chinese export? Research on such topics can provide implications for Chinese policymakers to formulate realistic environmental policies and employ information disclosure environmental regulation tools to coordinate the economic-environmental development. Using the 2003–2013 Annual Survey of Industrial Firms Database and difference-in-difference identification, we examine the effect of environmental information disclosure policy on firm exports and its impacting mechanisms. The empirical results show that the Chinese environmental information disclosure policy has reduced the scale of industrial firms’ exports in the regulated regions, indicating the existence of the pollution heaven effect in China. And also, we find that this policy mainly inhibits export activities of enterprises in coastal areas. Considering enterprise heterogeneity, the policy plays an inhibitory role in the exports of the non-state-owned firms, large firms, and low-productivity firms. Furthermore, the impact mechanism test shows that corporate financing constraint and production costs are important channels for environmental information disclosure policy affecting corporate export activities. It implies that, in developing countries such as China, policymakers and enterprises need to adopt forward-looking strategies to reduce the negative influence of environmental constraints on corporate exports and coordinate environmental governance and sound development of enterprises.

Environmental policies are a significant cornerstone of a developed economy, but the question that arises is whether such policies lead to a sustainable growth path. It is clear that the energy sector plays a pivotal role in environmental policies, and although the current literature has focused on examining the link between energy consumption and economic growth through an abundance of studies, it does not explicitly consider the role of institutional or governance quality variables in the process. Both globalization and democracy are important drivers of sustainability, while environmentalism is essential for the objective of gaining a “better world.” Governance quality is expected to be the key, not only for economic purposes but also for the efficiency of environmental policies. To that end, the analysis in this paper explores the link between governance quality and energy efficiency for the EU-28 countries, spanning the period 1995 to 2014. The findings document that there is a nexus between energy efficiency and income they move together: the most efficient countries are in the group with higher GDP per capita. Furthermore, the results show that governance quality is an important driver of energy efficiency and, hence, of environmental policies.

The odor problem caused by the decay of aquatic plants is widespread in many freshwater lakes. In this study, the spatial distributions of seven taste and odor (T&O) compounds (dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, 2-methylisoborneol, geosmin, β-cyclocitral, and β-ionone) in the sediments and overlying water of the east of Taihu Lake were investigated. The effects of plant and physico-chemical parameters on the release of T&O compounds were also analyzed. The results showed that high concentrations of T&O compounds were detected in the area where Eichhornia crassipes was flourishing. Volatile organic sulfur compounds were not found in the water source area, which was not covered by aquatic plants. High plant biomass and aquiculture activities might increase the release of the taste and odor compounds. The correlation between the concentrations of odorous compounds and nutrients in the sediment was also analyzed. The production of odorants was positively correlated with the nitrogen, and they may migrate from sediment to overlying water. The result suggested that controlling the plant density and aquaculture activities could reduce the release of odorous compounds.

Novel adsorbent, diethylenetriamine-grafted Spirodela polyrhiza (DSP), was synthesized via modifying natural S. polyrhiza (SP) with diethylenetriamine by cross-linking with epichlorohydrin and applied to adsorb Ni²⁺ and Pb²⁺ from water. The effecting parameters on adsorption of Ni²⁺ and Pb²⁺ such as adsorbent dosage, pH, contact time, temperature, and initial concentration were studied through equilibrium experiments. The adsorption of Ni²⁺ and Pb²⁺ followed the pseudo-second-order model and the Langmuir isotherm adsorption model. The study discusses thermodynamic parameters, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Ni²⁺ and Pb²⁺ on DSP, and revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum Ni²⁺ and Pb²⁺ adsorption capacities of DSP were 33.02 and 36.50 mg/g, respectively. The newly prepared materials were characterized through scanning electron microscopy (SEM), mapping analysis, and zeta potential analysis. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that functional groups (-OH and N-H) were involved in Ni²⁺ and Pb²⁺ adsorption. Notably, DSP can be easily regenerated and reused for multiple cycles. Therefore, DSP is a promising adsorbent for effective Ni²⁺ and Pb²⁺ removal.

As much wind power is connected to the power system, the accommodation of the wind power in the power grids becomes a huge challenge to the operation model of China’s power system. Releasing and improving the flexibility of the power system will be necessary and important to enable the accommodation of power generated with renewable energy sources, which is connected to the power grids on a large scale and accounts for a high proportion. The paper, with North Hebei as an example, discusses the relationship between the demand for the flexibility of thermal power units and the accommodation of wind power. This paper further analyzes the demand for peak load regulation in North Hebei at both the present and the future as well as the characteristics of power sources in the power grids of North Hebei and the technical potential of power generation. It also compares the quantity of curtailed power before and after the flexibility-oriented transformation of thermal power units in North Hebei and calculates the minimum technical output of thermal power under different levels of accommodation of wind power. The research shows that the peak load regulating resources in the power grids of North Hebei boast huge potential, but in the long term, to achieve the objective of a 10% curtailment rate of power generated with renewable energy sources, the minimum technical output of condensing units must be lower than the internationally advanced level of 25%. So, it is difficult to fulfill the said objective solely relying on the strengthened transformation of generating units. To reach the level of 5% curtailment rate of power generated with renewable energy sources, the minimum technical output must achieve breakthrough improvement, which requires continuous technological innovation and power flexibility in close coordination.