Food waste management (FWM) is considered to be an extremely important social issue besides an environmental one. Worldwide, it is estimated that 1.3 billion t/year of foods are disposed of in landfills (including edible and inedible foods). Moreover, FAO indicated that if food waste (FW) was a country, it could be the 3rd biggest CO₂ producer after China and the USA with more than 3.5–4.2 billion of t equivalence CO₂. Each citizen in the entire EU produces approximately 179 kg/year FW equal more or less with 600 €/year. This paper focuses on the concept of circular economy (CE) and how can we optimize and improve the production of biogas from UASB-R (upflow anaerobic sludge blanket reactor) using FW and natural minerals (clinoptilolite). The study was elaborated through laboratory scale experiments using different mixtures of FW, liquid waste from slaughterhouse (LWS), and natural clinoptilolite (Cli). The amount of biogas produced and the methane content of biogas were used as indicators in order to monitor and asses the performance of the anaerobic digester. The results of the present study were encouraging towards the use of FW in existing anaerobic treatment plants, suggesting selective collection at source of FW, diversion from landfills, and use as a secondary resource for energy recovery through a transition to a CE. The results indicate that the use of FW with zeolite duplicates the production of CH₄ within the same days of production compared with the control sample.

Fluoride is widely distributed in the environment, and excessive fluoride intake can induce cytotoxicity, DNA damage, and cell cycle changes in many tissues and organs, including the kidney. Accumulating evidence demonstrates that selenium (Se) administration ameliorates sodium fluoride (NaF)-induced kidney damage. However, the potentially beneficial effects of Se against NaF-induced cytotoxicity of the kidney and the underlying molecular mechanisms of this protection are not fully understood. At present, in this study, the normal rat kidney cell (NRK-52E) was used to investigate the potentially protective mechanism of Se against NaF-induced apoptosis, by using the methods of pathology, colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blot. The experiment was designed with a control group, two NaF-treated groups (NaF, 5, 20 mg/L), two sodium selenite-treated groups (Na₂SeO₃, 17.1, 34.2 μg/L), and four Se + NaF-treated groups (Na₂SeO₃, 17.1, 34.2 μg/L; NaF, 5, 20 mg/L). The results indicate that selenium can attenuate apoptosis and AMPK phosphorylation in the NRK-52E cell induced with fluoride. These results imply that selenium is capable to modulate fluoride-induced NRK-52E cell apoptosis via regulating the expression levels of the proteins involved in mitochondrial pathway and changes in p-AMPK expressions may also be a key process in preventing fluorosis.

In order to overcome photocatalytic technology application limitations in water due to weak light intensity, it is crucial to synthesize photocatalysts that respond to weak light. In this study, porous and oxygen-doped carbon nitride (CN-MC) was synthesized via supramolecular preassembly technology using melamine and cyanuric chloride. The carbon nitride catalyst produced via this technology has a relatively high surface area (63.2 m² g⁻¹), irregular pores, and oxygen doping characteristics, which enhance the light capture capacity, increase the number of reactive sites, and accelerate electron–hole separation efficiency. Thus, the CN-MC exhibited excellent photocatalytic activity during the degradation of organic pollutants Rhodamine B (RhB, 95% removal within 6 h) and tetracycline hydrochloride (TC-HCl, 70% removal within 6 h) under low-intensity light (the light intensity = 0.8~1.8 mW cm⁻² with a wavelength range of 300–700 nm). Mechanistic analysis showed that ·O₂⁻ and ·OH were the dominant active free radicals during RhB and TC-HCl photocatalytic degradation over CN-MC. The proposed synthesis strategy effectively improves the photocatalytic activity of graphite carbon nitride under weak light by producing a porous morphology and oxygen atom doping.

Today’s climate change is a major problem and challenge for the global environment and human civilization, and it can lead to dramatical floods over specific regions. As climate change intensifies, climate change adaptation strategies, such as flood insurance, energy taxes, and other risky financial strategies, have drawn worldwide attention and discussion. Risk control methods have been widely used to mitigate the impact of climate change on past flood losses, but past risk control strategies on climate change have not focused on the exploration of the relationship between environment, society, and humans. Based on the theoretical model of pro-environmental behavior, this study compares and analyzes four theoretical models and proposes a modified competitiveness model to effectively predict the pro-environmental behavior of college students with partial least squares (PLS) manner. Social norm could play a dominant role of mediator between risk perception, place attachment, and pro-environmental behavior. Although risk perception and local attachment are positively related to risk financial strategy, the promotion of social norms will increase the intention of risk financial strategy. For intention of risk financial strategies within pro-environmental behavior, the efficiency of enhancing local attachment was higher than that of risk perception.

The goal of this work was to evaluate the rice husk ash (RHA) effect on soil phosphorus (P) adsorption and to analyze the probable consequences of these in the parameters that affect P availability to the plants and the risk of soil P loss by superficial run-off. For this, a factorial experiment was conducted in laboratory with samples of two soils (factor A: Hapludult and Hapludox) that were submitted to five doses of RHA (factor B: 0; 25; 50; 75 and 100 g RHA kg⁻¹ of soil). The experimental units were plastic pots with 200 g of air-dry fine earth from horizon A of each soil. The experimental design was completely random with three replications. After 30 days of soils incubation where moisture was maintained in field capacity, the phosphorus adsorption isotherms were made in subsamples of each experimental unit. The RHA decreases sharply the phosphorus adsorption power but decreases very little the maximum soil phosphate adsorption. The RHA increases the soluble silicium and phosphorus contents, but these are not responsible for the decrease in phosphorus adsorption later applied in the soil. The major cause of the negative effect of RHA in the soil phosphate adsorption is the increase in soil pH. As a consequence of these effects, the RHA decreases the buffering ability and increases the phosphorus effective diffusion coefficient in the soil. Moreover, as a consequence of the adsorption power decrease, the RHA increases the risk of environmental contamination by phosphorus by superficial runoff, especially in soils with originally low phosphorus adsorption ability.

The northern Beibu Gulf is one of the major habitats for the Indo-Pacific humpback dolphin (Sousa chinensis) in China. In this habitat, the core distribution zone of humpback dolphins was confined to the Sanniang Bay (SNB) and Dafengjiang River Estuary (DRE) areas. In our present research, the sediments of 14 sampling sites across the SNB and DRE waters were collected and further conducted for microbiomic and environmental analysis to explore the ecosystem characteristics of major humpback dolphin habitats in Northern Beibu Gulf. The environmental condition includes ammonia nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N), dissolved reactive phosphorus (DRP), sulfur content in the form of sulfuric acid (SO₄²⁻-S), Fe, and heavy metals (including Cu, Zn, Cd, Pb, and As). The composition of the bacterial community was characterized by 16S ribosomal DNA analysis of the V3–V4 regions using the Illumina-based sequencing platform. The environmental characteristic of the nutrient elements and heavy metals indicated that SNB suffered more anthropogenic impact than DRE. The comparably higher concentration of NH₄⁺-N, NO₃⁻-N, DRP, Pb, and Cd in the SNB region was detected. The comparably higher nutrients in the SNB may have resulted in higher biomass and lower dissolved oxygen (DO) profile, which was further proved by Landsat thermal image data. The microbiome analysis showed that the DRE region was oligotrophic and SNB reflected an anaerobic environment in the sediments. Environmental factors rather than the spatial distance determined the similarity of bacterial community among different sites. Ecological associations between environmental, oceanographic, and bacterial characteristics were illustrated, which exhibited strong mutual associations. Our findings presented a feasibility that integrates empirical and remote sensing data to distinguish ecological features and evaluate ecosystem healthiness for the humpback dolphin habitats.

With the revitalization of the old industrial bases in Northeast China, the development of the energy industry is particularly significative. The purpose of this paper is analyzing the decoupling of carbon emissions and placing emphasis on Liaoning’s energy industry. The researchers used the logarithmic mean Divisia index (LMDI) decompose model to take into account carbon emissions in each energy industry and used the Tapio decoupling model from 2000 to 2015 to seek the decoupling states. The main completion of this study are as follows: (1) The EGH and OPC industry are the dominating components of the carbon emissions of the energy industry. The coal and crude oil accounted for 95% of energy industrial consumption; there is great potential for electricity to replace coal and crude oil. (2) The direction of the changes in economic growth, investment structure, investment dependence, and energy structure is the same as industrial carbon emissions. Meanwhile, energy intensity and energy technology are the opposite during the period. (3) The CMW and PGE industry occurred strong decoupling between carbon emissions and economic output since 2005; there is weak decoupling state in other industry. And the PGE and OPC industry occurred recessive coupling and weak negative decoupling between carbon emissions and energy intensity except 2011 and 2012.

Passive samplers based on diffusive gradients in thin hydrogel films (DGT) were recently modified for sampling of polar organic compounds in water. However, since the sampling rates of the commonly used DGT design with the surface area of 3.1 cm² are low, we propose to increase them by applying a two-sided design with a larger sampling surface area of 22.7 cm². The sampler design consists of two sorptive hydrogel disks compressed between two diffusive hydrogel disk layers strengthened by nylon netting and held together by two stainless steel rings. Sorbent/water distribution coefficients (KSW) were determined, and the sampler was calibrated for monitoring 11 perfluoroalkyl substances and 12 pharmaceuticals and personal care products in water at laboratory conditions using a closed system with artificial flow generated by submersible pumps. A field performance test was conducted at five locations in the Morava River basin in Czech Republic. The median value of laboratory-derived sampling rates was 43 mL day⁻¹ with extreme values of 2 mL day⁻¹ and 90 mL day⁻¹ for perfluorotridecanoic and perfluoroheptanoic acids, respectively. The log KSW values of tested compounds ranged from 3.18 to 5.47 L kg⁻¹, and the estimated halftime to attain sampler-water equilibrium ranged from 2 days to more than 28 days, which is the maximum recommended exposure period, considering potential issues with the stability of hydrogel. The sampler can be used for assessment of spatial trends as well as estimation of aqueous concentration of investigated polar compounds.

In this study, the validity of the environmental Kuznets curve (EKC) hypothesis is examined with the newly developed bootstrap autoregressive distributed lag (ARDL) approach by incorporating the effects of trade openness for Turkey from 1969 to 2017. The bootstrap ARDL approach results show that there is a long-run relationship between per capita carbon dioxide (CO₂) emissions, per capita real income, and trade openness in the presence of one structural break. The results of the long-run estimators indicate that the inverted U-shaped EKC hypothesis is valid, and trade openness has an increasing impact on CO₂ emissions. However, Turkey has not yet reached the level of income necessary to reduce pollution. The results of the Fourier Toda–Yamamoto Granger causality test also show that unidirectional causality runs through per capita real income and trade openness to per capita CO₂ emissions. In addition to these findings, it has been determined that the decrease in growth rate and production experienced during the 2001 financial crisis in Turkey reduced environmental pollution in both the short and long runs. Consequently, these results show that the scale and composition effects outweigh for economic growth and trade openness in Turkey.

The objective of this study was to investigate the temperature sensitivity of labile and relatively recalcitrant forest soil carbon (C) pools amended with biochar during short-term incubation. Biochars were prepared using sugar cane residue under pyrolysis temperatures of 300 and 700 °C (i.e., BC300 and BC700), respectively. Coarse particulate organic matter and acid hydrolysis residue were separated from a forest soil and treated as the labile and recalcitrant C pools of the soil, respectively. Temperature sensitivity of the soil C pools was characterized using the Q₁₀ values (i.e., the proportional increase in respiration per 10 °C rise). The increased Q₁₀ values of treatments in the earlier stage were attributable to instantaneously increased aromatic C content. The following decreased Q₁₀ values were related to the consumption of labile C. However, the two types of biochars led to similar Q₁₀ values in the same C pools at the later stage of incubation, which was closely related to the nearly humic-like component content in the dissolved organic matter. The different temporal distributions of Q₁₀ values were attributable to changes of aromatic C content and continuous consumption of labile components.