In the contemporary era, it is evident that consumption-based carbon emissions (CCO2e), adjusted for international trade, are a more accurate and robust measure of environmental pollution than production-based emissions. Therefore, many studies have focused on exploring the determinants of CCO2e; however, the literature could not yet discern environment-related R&D budget (ERRD) and political risk index (PRI) as a new driver. To fill this gap, the current paper aims to divulge the dynamic effects of ERRD and PRI on CCO2e while taking imports, exports, and GDP as control regressors. To do so, the G7 nations’ data from 1990 to 2020 is utilized, and several advanced econometric tests and techniques are deployed to tackle the advanced issues (i.e., cross-section dependence, heterogeneity, and endogeneity) in econometrics. The CS-ARDL estimates suggest that PRI and ERRD significantly lessen the environmental quality by disrupting the detrimental effects of CCO2e. Likewise, the rise in exports possesses a negative association with the ratio of CCO2e. However, CCO2e significantly tends to surge on account of an increase in GDP and imports. GDP squared exhibits the negative link with CCO2e, confirming the EKC hypothesis in G7 nations. Besides, the AMG technique and causality test validate the robustness of our findings. In addition, the policies related to CCO2e by authorities will take approximately more than a year to absorb their effects.

Cadmium, lead, mercury, and arsenic are among the most toxic environmental contaminants. Serum alanine aminotransferase (ALT) is the most common liver biomarker. This analysis aimed to explore the associations between blood cadmium, lead, mercury, urinary total arsenic, and dimethylarsinic acid and ALT elevation in adults. Data were extracted from 5 National Health and Nutrition Examination Survey cycles (NHANES) 2007–2016. Patients with chronic viral hepatitis and excessive alcohol consumption were excluded. ALT elevation was defined according to the 2017 American College of Gastroenterology Clinical Guideline. Logistic models and restricted cubic splines were adopted to assess the exposure–response relationships. Comparing the highest to lowest quintile of exposure, the multivariable-adjusted odds ratios (95% confidence intervals) of ALT elevation were 1.38 (1.07–1.78) for blood lead (Pfₒᵣ ₜᵣₑₙd = 0.01), 1.37 (1.16–1.62) for blood mercury (Pfₒᵣ ₜᵣₑₙd < 0.01), 0.94 (0.78–1.14) for blood cadmium (Pfₒᵣ ₜᵣₑₙd = 0.64), 1.07 (0.79–1.45) for urinary total arsenic (Pfₒᵣ ₜᵣₑₙd = 0.81), and 1.25 (0.94–1.66) for urinary dimethylarsinic acid (Pfₒᵣ ₜᵣₑₙd = 0.18). The associations between blood lead and mercury and ALT elevation were only observed in women. In addition, the associations between urinary total arsenic [1.53 (1.02–2.29), Pfₒᵣ ₜᵣₑₙd = 0.02] and dimethylarsinic acid [2.17 (1.05–4.49), Pfₒᵣ ₜᵣₑₙd = 0.02] and ALT elevation were also observed in women. Dose–response analysis showed that there was no safe exposure threshold of blood lead and mercury’s toxic effect on ALT elevation, respectively. In conclusion, lead, mercury and arsenic were associated with ALT elevation in adults, and the associations were mainly observed in women.

In order to effectively analyze and explore the socio-economic impact of haze pollution, the article constructs a comprehensive two-stage decomposition model to verify that technological progress plays a key role in controlling haze pollution. And for the first time, a macro-level research framework for the rebound effect of haze pollution has been constructed to compare and analyze the heterogeneity of the rebound effect of technological progress in different industries in different regions. The study found that (1) during the period 2000–2017, haze pollution situation deteriorated. Economic effects were the main reasons for haze pollution. Among these effects, technological progress was the main driving force for haze control, followed by the emission intensity during 2000–2011 and the reduction of industrial structure since 2014. (2) The significant drive of emission reduction is in the secondary industry, showing a trend of first increasing and then decreasing. Besides, there was a difference in spatial distribution, which shows an increased trend from east to west. (3) The rebound effect of haze pollution at the macro level in China presented high-level fluctuations, and there were certain spatial distribution differences. However, due to the convergence of technological development stages, regional differences have a gradual convergence trend. In the future, in the process of haze control, it is necessary to increase support for technological innovation, implement energy total control and price reform, promote technological progress, and implement differentiated haze reduction policies to solve problems according to local conditions.

This study investigated the isotope effects of δ¹³C and δ¹⁵N and microbial response during biodegradation of hydrocarbons by biostimulation with nitrate or compost in the petroleum-contaminated soil. Compost and KNO₃ amendments promoted the total petroleum hydrocarbon (TPH) removal accompanied by a significant increase of Actinobacteria and Firmicutes phyla. Soil alpha diversity decreased after 90 days of biostimulation. An inverse significant carbon isotope effect (εc = 16.6 ± 0.8‰) and strong significant nitrogen isotope effect (εN = −24.20 ± 9.54‰) were shown by the KNO₃ supplementation. For compost amendment, significant carbon and nitrogen isotope effect were εc = 38.8 ± 1.1‰ and εN = −79.49 ± 16.41‰, respectively. A clear difference of the carbon and nitrogen stable isotope fractionation was evident by KNO₃ or compost amendment, which indicated that the mechanisms of petroleum degradation by adding compost or KNO₃ may be different.

Due to the increasing concerns of heavy metal contamination in greenhouse soil, the safe production of vegetables, especially leafy vegetables, is largely limited. In this study, the cadmium (Cd) concentration and major nutritional qualities of 23 main celery cultivars from China were compared in a greenhouse experiment. Large genotypic differences in biomass, cadmium accumulation and nutrition traits were observed. The biomass of cultivars Hongqin (HQ), Jialifuniyadiwangxiqin (JZ), Jinhuangqincai (JH) and Shanqincai (SQ) was significantly higher than that of the others. The Cd concentration in the edible part ranged from 0.53 to 2.56 mg·kg⁻¹ DW, of which SQ exhibited the lowest Cd concentration. In addition, SQ had the lowest Cd transport factor (TF) and bioconcentration factor (BCF), followed by Liangfengyuqin (LF). Simultaneously, both genotypes had a relatively higher chlorophyll content and vitamin C concentration and lower cellulose content. Therefore, the two genotypes SQ and LF were selected as promising candidates for growth in a moderately Cd-contaminated greenhouse to achieve safe production. Further correlation analysis and redundancy analysis showed that the Cd concentration in the edible part was positively correlated with the cellulose content but negatively correlated with the vitamin C concentration. The results of celery variety screening provide a safe production strategy for moderately polluted greenhouse vegetable soils.

Urban water pollution has been well controlled by strict management in the past few decades in China. Thus, the central government started to place emphasis on rural water pollution, and increasing number of sewage treatment facilities have been constructed, and currently, they are operating in China. Therefore, thoroughly assessing the operating conditions and the performance of these facilities is important. This article analyzes life cycle assessment and life cycle cost to evaluate the environmental and economic performance of four common technologies to determine how the emerging rural sewage treatment facilities in China are running. The results showed that the plant-adopted anaerobic-anoxic–oxic process was an optimal scheme for lower environmental impact that was also cost-effective. All technologies had similar impacts on eleven environmental categories. Due to cement consumption during the construction phase and electricity consumption during the operation phase, the marine aquatic ecotoxicity potential was the greatest contributor, accounting for approximately 90% of the total potential impact. In addition, this research revealed that electricity consumption during the operation phase was responsible for almost all environmental impact categories, except for eutrophication potential and ozone layer depletion potential categories. Lastly, scenario analysis indicated that reusing treated water and adjusting power structure could be useful measures to promote the sustainable development of rural water environments.

When old corrugated cardboard (OCC) is returned to the paper mill for repulping and reuse, the starch, which is added to the paper surface as a reinforcement agent, is dissolved into the pulping wastewater. Most of the OCC pulping wastewater is recycled to save precious water resources; however, during the water recycling process, the accumulation of dissolved starch stimulates microbial reproduction, which causes poor water quality and putrid odor. This problem seriously affects the stability of the papermaking process and product quality. In this study, phosphomolybdic acid (H₃PMo₁₂O₄₀, abbreviated as PMo₁₂) was utilized to catalyze the waste starch present in papermaking wastewater to monosaccharides, realizing the resource utilization of waste starch. The results showed that the optimized yield of total reducing sugar (78.68 wt%) and glycolic acid (12.83 wt%) was achieved at 145 °C with 30 wt% PMo₁₂ at pH 2, which is equivalent to 91.51 wt% starch recovered from wastewater for resource utilization. In addition, the regeneration of the reduced PMo₁₂ was realized by applying a potential of 1 V for 2 h. Overall, this study has theoretical significance and potential application value for resource utilization of waste starch in OCC pulping process and cleaner management of OCC waste paper.

This research investigated the impact of aluminum sulfate (AS) as amendment to different types of litter (new, reused, and mixed litters) for reducing ammonia emission and improving productive performance of local dual-purpose breeding hens. A total of 450 hens and 60 cocks from the Inshas strain were randomly assigned to six groups (five replicates each of 15 hens + 2 cocks) raised in pen floor furnished with a wheat straw litter. The groups included: (1) new, (2) reused, (3) mixed (50% new + 50% reused) litter; the other groups (4, 5 and 6) were respectively housed on the same litter as groups 1, 2 and 3 but with the addition of 495 g of AS/m² litter. The feed conversion ratio was better for layers raised on new litter with or without AS than other groups. Different kinds of litter had different moisture (p < 0.05) and pH (p < 0.05) values. Birds raised on litter types treated with AS significantly (p < 0.05) decreased intestinal pH and decreased total bacterial count compared to the same litter types without AS at the end of the experiment. Birds raised on new litter supplemented with AS had the highest plasma T3, total protein, globulin, Hgb, and PCV% and the lowest levels of uric acid and cholesterol at the end of the experimental period. Therefore, litter amendment with AS, also the mixed or reused one, could be recommended to reduce ammonia and, in turn, increasing plasma T3 and decreasing total bacterial count, leading to increasing bird’s performance.

Paddy-upland rotation and/or straw return could improve soil structure and soil nutrient availability. Different previous crops (wheat and/or oilseed rape) and straw return methods (straw mulching and/or returning) might increase soil organic carbon (C) and total nitrogen (N) content, and further affected the ammonia (NH₃) volatilization, nitrous oxide (N₂O), and methane (CH₄) emissions. A comparison study was carried out in a located field experiment started from 2014 in Central China, aiming to exam seasonal and annual NH₃, N₂O, and CH₄ emissions under the wheat-rice (WR) and oilseed rape-rice (OR) rotations. Three treatments were chosen, i.e., (i) no chemical N fertilizer application (PK), (ii) chemical nitrogen-phosphorus-potassium combination (NPK), and (iii) chemical NPK with straw returning (NPK+St). We found that after 3 years of cultivation, treatment with straw return increased soil total N content and organic C by 15.57% and 17.11% on average as compared with the NPK treatment, respectively. Straw return did not generate additional NH₃ and N₂O losses during the rice season after improving soil fertility. However, CH₄ emissions increased by 45.35% on average after straw return in summer. In winter, straw return increased NH₃, N₂O, and CH₄ emissions by 70.12–85.23%, 16.93–22.97%, and 7.18–9.17%, respectively. The stimulation of NH₃ volatilization mainly occurred in the topdressing stage. Compared with WR rotation, OR rotation had no significant effect on NH₃ and CH₄ emissions, and the change of N₂O emission might be related to the increase of soil C and N pools. The retention of residues in the process of straw decomposition may be the main factor leading to the difference of gas emission between the paddy-upland rotation and straw return.

The imminent arrival of nanoparticles (NPs) to the wastewater treatment plants (WWTP) brings concern about their effects, which can be related to the wastewater composition. In this work, the effects of titanium dioxide (TiO₂) NPs in the removal of carbon, nitrogen, and phosphorus by activated sludge bioreactors during the treatment of synthetic, raw, and filtered wastewaters were evaluated. Floc size, compaction of sludge, and morphological interactions between sludge and NPs were also determined. The main effect of TiO₂ NPs was the inhibition of up to 22% in the removal of ammonia nitrogen for all types of wastewaters. This effect is strong dependent on combined factors of TiO₂ NPs concentration and content of organic matter and ammonia in wastewater. The removal of dissolved organic carbon was affected by TiO₂ NPs in lower level (up to 6%) than nitrogen removal for all types of wastewaters. Conversely to adverse effects, the removals of orthophosphate in the presence of TiO₂ NPs were improved by 34%, 16%, and 55% for synthetic, raw, and filtered wastewater, respectively. Compaction of the sludge was also enhanced as the concentrations of NPs increased without alterations in the floc size for all types of wastewaters. Based on TEM and STEM imaging, the main interaction between TiO₂ NPs and the activated sludge flocs was the adsorption of NPs on cell membrane. This means that NPs can be attached to cell membrane during aerobic wastewater treatment, and potentially disrupt this membrane. The effects of TiO₂ NPs on macronutrient removal clearly depended on wastewater characteristics; hence, the use of realistic media is highly encouraged for ecotoxicological experiments involving NPs.