This paper uses static and dynamic panel regression to measure the effect of energy consumption on air quality of 20 heavily polluted cities in the Yangtze River Delta of China. Further, the influence of the relevant policies on the relationship between energy consumption and air quality is tested with the method of regression discontinuity. This study concluded the following: (1) When energy consumption structure, industrial structure, and energy efficiency are taken into account, the effect coefficient of energy consumption on air quality is 0.4579, meaning that controlling energy consumption tends to improve the air quality positively. (2) The emission of sulfur dioxide is characterized by inertia; the annual increase in sulfur dioxide emissions in the previous year will lead to an increase of 0.427% in the annual emissions. (3) The relationship between energy consumption and air quality of different cities varies, and these cities can be divided into four categories. (4) The relevant policies for improving air quality are effective to some extent. This study indicates that the Yangtze River Delta should focus on actively changing the mode of energy development.

Phytoremediation potential of duckweeds (Lemna minuta, Lemna minor) to remove nutrients from simulated wastewater was analyzed. In two separate experiments, the two species were grown for 28 days in waters enriched with nitrate and phosphate to simulate nutrient concentrations of domestic wastewater. Water physical and chemical measurements (temperature, pH, conductivity, oxygen) and plant physiological and biochemical analysis (biomass, relative growth rate–RGR, nutrient and chlorophyll contents, peroxidative damage, bioconcentration factor–BCF) were made to test and compare the phytoremediation capacity of the two Lemna species. L. minuta biomass increased almost tenfold during the time-course of the treatment resulting in a doubling of the mat thickness and a RGR of 0.083 ± 0.001 g/g day. Maximum frond content of phosphate was reached by day 21 (increase over 165%) and nitrate by day 7 (10%). According to the BCF results (BCF > 1000), L. minuta was a hyperaccumulator for both nutrients. On the other hand, L. minor biomass and mat thickness decreased continuously during incubation (RGR = − 0.039 ± 0.004 g/g day). In L. minor fronds, phosphate content increased until day 14, after which there was a decrease until the end of the incubation. Frond nitrate content significantly decreased by day 7, but then remained relatively constant until the end of the experiment. L. minor proved to be hyperaccumulator for phosphates, but not for nitrates. Results indicated L. minuta has a greater potential than L. minor to remove both nutrients by bioaccumulation, especially phosphates, demonstrated also by better physiological and biochemical responses. However, during the incubation, the chlorophyll content of L. minuta mat did continuously decrease and peroxidative damage had increased until day 14, indicating that the system was under some kind of stress. Strategies to avoid this stress were discussed.

Manure-based fertilizer is usually applied to agricultural soils to increase soil fertility and improve soil quality. However, this practice has an impact on the soil environment, e.g., increasing heavy metal contents. The aim of this study was to evaluate and estimate the accumulation tendencies of eight heavy metals, including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), manganese (Mn), and zinc (Zn) in a soil fertilized continuously with dairy manure through a 5 years’ field-scale experiment. Contents of the As, Cd, Cr, Cu, Mn, and Zn gradually increased with the fertilization time of dairy manure at the stable rate of around 326 t hm⁻² year⁻¹, leading to annual mean increases of 3.6%, 2.4%, 3.9%, 3.8%, 4.2%, and 6.1%, respectively. Based on the prediction of a dynamic mass balance model using the current practice, the contents of Cd and Zn in the fertilized soil would reach the Chinese standard values for agricultural soils in 48 and 35 years. The mitigation measures, such as lower application rates, for the environmental risk of heavy metal accumulation should be considered.

A facile solution processing strategy has been developed for the formation of Ag-modified ZnO microneedles at various calcination temperatures such as 300, 500, and 700 °C (AZ3, AZ5, and AZ7 respectively). Due to the heavy doping of AgNO₃, Ag⁺ ions have been incorporated in to the crystal lattice of ZnO in all the Ag-ZnO samples, which facilitated the formation of Ag-ZnO microneedle morphology with minimized defect states, and obviously, the plasmon peaks were observed due to Ag modification. These Ag-ZnO microneedle structures have been evaluated for their photocatalytic performance using methylene blue as model target contaminant and their activity was compared with the commercially available titania P25 photocatalyst. The photoactivity of all the Ag-ZnO microneedle structures was significantly higher than that of the commercially available P25 photocatalyst with the most active Ag-ZnO material having a photocatalytic activity ~ 1.4 times greater than that of P25 titania.

Due to a technologic progress, a growth in the renewable energy markets including a high number of manufactures coming to being, the Renewable Energy Sources (RES) are both a tool for mitigating climate changes and investments that can provide direct economic profits and reduce a political or economic dependence resulting from import of fossil fuels. One of the many key solutions toward fulfilling the global increasing demand for energy and reduction of CO₂ emissions is applying solar technologies. This paper presents the results of the analysis conducted for a small public office building located in Bialystok (Poland), where solar collectors were considered as the RES for domestic hot water (DHW) system, on the understanding that existing oil boiler would be an additional source. Low values of recommended water consumption in office buildings resulted in a low energy demand. However, concerning a potential of all office governmental buildings in Poland, it would be possible to reduce CO₂ emission by 17,248 tonnes. In the comprehensive analysis, the same building in two more locations (Cordoba (Spain) and Kaunas (Lithuania)) was considered using simulation tools delivered within the framework of VIPSKILLS project as well as EnegyPlus software. The results allow to compare the mean monthly efficiency of systems or number of collectors necessary to deliver similar amount of solar energy.

Thiamethoxam (TMX) is a widely used neonicotinoid insecticide for its effective potential for controlling insects from the agricultural field, which might induce toxicity to the aquatic biota. In this study, the role of the probiotic Bacillus subtilis (BS) and a phytogenic oil extract of Thymus vulgaris essential oil (TVEO) in the modulation of thiamethoxam (TMX)-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus) has been evaluated. Fish were subjected to TMX (5 mg L⁻¹) and fed with a diet either supplemented with BS (1000 ppm) or TVEO (500 ppm). The experiment lasted for 1 month. By the end of the experiment, blood was sampled for biochemical analysis and fish organs and tissues were collected for histopathological and immunohistochemical examinations. Results showed a substantial increase of serum markers of hepatorenal damage such as the activities of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) and levels of blood urea nitrogen (BUN) and creatinine with an obvious decrease of serum protein levels in the TMX-intoxicated group. Also, there was a considerable increase in malondialdehyde (MDA) levels and glutathione-S-transferase (GST) activity. TMX remarkably suppressed serum lysozyme activity, respiratory burst activity, and phagocytosis with a conspicuous elevation of the levels of interleukins (interleukin-1 beta (IL-1β) and interleukin-6 IL-6). The histopathological findings showed that TMX induced degenerative changes and necrosis in the gills, liver, head kidneys, and spleen of the intoxicated fish. Significant alterations of frequency, size, and area percentage of melanomacrophage centers (MMCs), decreased splenocyte proliferation, and increased number of caspase-3 immunopositive cells were also observed. Contrariwise, the concurrent supplementation of either BS or TVEO in the diets of catfish partially mitigated both the histopathological and histomorphometric lesions of the examined tissues. Correspondingly, they improved the counts of proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive splenocytes. In conclusion, the co-administration of either BS or TVEO in catfish diets partially diminished the toxic impacts of TMX. Nonetheless, the inclusion of TVEO in the diets of catfish elicited better protection than BS against TMX-induced toxicity in response to its potential anti-inflammatory, antioxidant, anti-apoptotic, and immune-stimulant effects.

This work aimed to explore a new technique for improving the performance of solar stills (SSs) through utilizing three different types of a new hybrid structure of heat localization materials (HSHLM) floating on the water surface to increase the evaporation rate as well as water production and minimize heat losses. The three types were exfoliated graphite flakes with wick (type A), carbon foam with wick (type B), and exfoliated graphite flakes with wick and carbon foam (type C). These hybrid structures had good features such as high absorption and hydrophilic capillary forces to interconnected pores for fluid flow through the structure. Two identical SSs were designed, fabricated, and investigated to assess SSs’ performance with and without HSHLM (modified and conventional SSs). The obtained results showed that the daily productivity was enhanced by 34.5, 28.6, and 51.8% for type A, type B, and type C, respectively, relative to the conventional one. Moreover, the efficiency of the SS reached about 37.6% for type C; while, it reached about 27% for the conventional SS. Contrary to conventional SSs, the use of HSHLM resulted in increasing the productivity proportional to water depth.

Pontederia cordata is a heavy metal accumulator, while the heavy metal tolerance mechanisms of this plant are not well understood. Hydroponic experiments were used to assess the effects of Cd²⁺ on antioxidative activities, osmoregulatory substances and photosynthesis in leaves. Exposure of 5 mg L⁻¹ Cd²⁺ for 7 days, the photosynthetic apparatus functioned normally and sustained a relatively high photosynthetic rate, and good growth was observed. Under 50 and 75 mg L⁻¹ Cd²⁺, accelerated lipid peroxidation and increased peroxidase activity (POD; E.C.1.11.1.7) were detected, while no significant differences were observed in superoxide dismutase (SOD; E.C.1.15.1.1) and catalase (CAT; E.C.1.11.1.6) activities, as well as in lutein, ascorbic acid, and glutathione contains of leaves. Proline content increased, while soluble sugar and soluble protein contents decreased under 75 mg L⁻¹ Cd²⁺. Cd²⁺ at different concentrations induced a reduction in carotenoid, total carotenoid, and ascorbic acid-dehydroascorbate contents. A significant increase in phytochelatin content was induced by 75 mg L⁻¹. Chlorophyll content decreased under Cd stress and disturbed photosynthesis, causing dramatic reductions in photosynthetic parameters. Stomatal closure was responsible for a reduced photosynthetic rate under Cd²⁺ exposure. Cd²⁺ concentrations of no less than 25 mg L⁻¹ disorganized the photosynthetic apparatus, induced the partial closure, and decreased activity of the photosystem II (PS II) reaction center, thus disturbing light conversion and utilization, thereby decreasing the photosynthetic efficiency in PS II.

Heavy metals have a separate precaution in the air pollution components as they are not easily deteriorated in nature, they tend to bioaccumulate, they are carcinogenic or poisonous, and they can be toxic even at low concentrations. Therefore, monitoring of heavy metal pollution is of great importance. Plants are frequently used as biomonitors to monitor the heavy metal pollution. However, the heavy metal accumulation capacities of plants can vary considerably depending on the plant species, as well as on the organelle basis and the amount of particulate matter in the environment. It is also very important to determine how much of the heavy metal concentrations found in plants are derived from the plant species and how much from the particulate matter on the organ. In this study, it was aimed to determine the change of heavy metal accumulation in some landscape plants grown in the city center of Kastamonu depending on plant type, plant organism, washing status, and traffic density. For this purpose, leaf and branch samples were collected from individuals of Ligustrum vulgare L., Euonymus japonica Thunb., Biota orientalis L., Juniperus sabina L., Berberis thunbergii DC, Mahonia aquifolium (Pursh) Nutt., and Buxus sempervirens L., which are frequently used in urban landscape designs growing in areas with heavy, low dense, and no traffic. Some of the collected samples were washed, and heavy metal analyses were conducted to determine the amount of Pb and Mg concentrations. It was remarkable that Pb concentration was higher in branches than in the leaves for all the species. And the alteration depending on traffic density on the base of the factors studied was in different proportion depending on the metals.

According to the World Health Organization (WHO), in 2016, 91% of the global population was living in places where guidelines on air quality were not met, which results in an estimated figure of seven million deaths annually. The new Brazilian air quality standards, CONAMA 491/2018, was the first revision in over two decades and has as final target the WHO guidelines for air quality, although no deadline has been established for implementation. The goal of this work was to quantify public health gains of this new policy based on hospitalizations due to respiratory diseases, the most studied outcome in Brazilian time series studies, in four Brazilian Southeast capitals: São Paulo (SP), Rio de Janeiro (RJ), Belo Horizonte (MG), and Vitória (ES) for PM₁₀, PM₂,₅, SO₂, CO, and O₃. Population and hospitalizations data for all respiratory diseases for people under 5 years old, over 64 years old, most vulnerable populations, and all ages were analyzed. The air quality monitoring data was analyzed in two different periods: 2016 to 2018 for São Paulo and Vitória; and between 2015 and 2017 for Belo Horizonte and Rio de Janeiro, according to available monitoring data. A literature review was carried out to determine the appropriate relative risk to be used in the estimations, and the public health gains were calculated based on the selected relative risks for each city. The highest estimate was for São Paulo, with 3454 avoidable respiratory hospital admissions (all ages). In total, the four cities accounted for 4148 avoidable hospitalizations, which was associated to $1.1 million public health gains. Results considering the day of exposure (lag 0) were superior to those with the 5-day moving average (lag 5). The results highlighted the importance of adopting more restrictive standards and called for public policies, the necessity of expanding the air quality monitoring network, mapping emission sources, and improve the knowledge about the interaction between air pollution and health outcomes beyond respiratory disease for the region.