A novel non-toxic hybrid BiVO₄-GO-TiO₂-polyaniline (PANI) (BVGT-PANI) composite with superior photocatalysis was successfully prepared via a one-pot hydrothermal reaction. The structural and morphological characterizations of the synthesized compounds were analyzed by a series of techniques. We found excellent photocatalytic efficiencies for methylene blue (MB) and phenol degradation under visible light irradiation after adhering the PANI to the photocatalyst. The degradation rates of MB and phenol reach up to approximately 85% and 80%, respectively, after 3 h of irradiation. For photodegradation MB, BVGTA exhibit the highest kₐₚₚ rate constant of about 1.06 × 10⁻² min⁻¹, which is about 1.63-fold faster than BVG and 2.94-fold faster than BVGT. For photodegradation of phenol, BVGTA exhibits the highest kₐₚₚ rate constant, of about 8.86 × 10⁻³min⁻¹, which is about 1.2-fold faster than BVG and 1.96-fold faster than BVGT. Furthermore, vitro toxicity test against Bacillus subtilis and Staphylococcus aureus demonstrated that the nanophotocatalyst is non-toxic.

The use of banana peel as a sustainable and low-cost precursor for the fabrication of effective biochar was exploited. Here, calcined magnetic biochar (CMB) was fabricated and characterized. CMB possesses surface acidic functional groups (–OH and COO⁻), porous structures, high saturation magnetization (39.55 emu/g), and larger surface area than the non-magnetic biochar (CB). The CMB adsorption performance (72.8, 75.9, and 83.4 mg/g for Zn²⁺, Cu²⁺, and Hg²⁺, respectively at pH 6) in a single component was described suitably by pseudo-second order kinetic model, Langmuir, and Redlich-Peterson adsorption isotherms. Notably, the selectivity factor values in the extended Langmuir isotherm indicated that CMB has higher adsorption affinity toward Hg²⁺ than Cu²⁺ and Zn²⁺ in the multi-component system. Owing to its high adsorption efficiency and fast and easy separation, the calcined magnetic biochar is considered promising and effective for the purification of heavy metal–bearing wastewater.

Complex land use patterns and intense human activities significantly affect the spatial distribution of heavy metals in soils. This is especially true in peri-urban areas. The land use in peri-urban areas is complex and the risk of heavy metal pollution is relatively high. Identifying the correlations between land use patterns and spatial distribution of heavy metals in peri-urban soils is important for enhancing soil security and sustaining soil ecosystem services in areas undergoing rapid urbanisation. In this study, soil samples were collected from 82 experimental sites in a typical peri-urban watershed in eastern China. Copper (Cu), zinc (Zn), cadmium (Cd), nickel (Ni), arsenic (As), chromium (Cr), lead (Pb) and mercury (Hg) concentrations at different soil depths were analysed. Results showed that heavy metal concentrations in peri-urban soils were significantly affected by land use type and varied with soil depth. Farmland had the highest heavy metal concentrations, whereas forestland had the lowest concentrations; the concentrations in soils decreased with increasing soil depth. Spatial analysis of heavy metals in soils showed that their concentrations rapidly increased with the increasing percentage of town areas in buffer zones. This indicated that land use structure influenced the heavy metal concentrations in peri-urban soils and the influences were correlated to the locations of towns and villages. Correlation analysis showed that Cu, Zn, Cd, Pb and Hg concentrations in soils were significantly affected by altitude, distance from roads, distance from towns and villages and soil clay content. Interestingly, historic land use was also found to affect heavy metal concentrations in forestland. These results can provide scientific guidance for designing effective soil management practices for peri-urban areas.

Crocin (C₄₄H₆₄O₂₄) is an isolated bioactive molecule of saffron extract. It has different pharmacological effects such as antioxidant and anti-inflammatory activities. In the present study, radioprotective property of crocin was investigated in the rat liver. Thirty-two rats were equally divided into four groups: (1) control (normal saline), (2) crocin (200 mg/kg), (3) γ-rays (6Gy), and (4) crocin plus γ-rays-treated groups. The liver histopathology, serum transaminases (ALT and AST), alkaline phosphatase (ALP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and hepatic lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) have been assessed. The histopathological result of hepatic tissue in group 3 showed hydropic degeneration and this progressed to focal or spotty necrosis through the lobule. Moreover, some sinusoids are distended with blood or with leukocytic infiltrations. Other cases in group 3 showed periportal leukocytic infiltrations and necrosis extended out from the portal tract to involve hepatic lobules with fibrinous necrosis in portal vessels, while the examination of hepatic tissues of group 4 showed reduced deformities, irregular arrangement, congested hepatic vessels, and necrosis in hepatocytes. The results also showed significant decreased level of liver function activities, inflammatory markers, lipid peroxidation, and increased levels of liver antioxidants enzymes in group 4. Crocin showed moderate protective effect against γ-rays-induced liver toxicity. The antioxidant effect of crocin may be a major reason for its positive impact on liver parameters. Graphical abstract .

Quantitative identification of anthropogenic trace metal sources in surface river sediments is vital for watershed pollution control and environmental safety. In this study, we developed a reliable approach by integrating enrichment factor (EF), multiple linear regression of absolute principal component scores (MLR-APCS), and Pb stable isotopes, and applied it to a typical hilly agricultural watershed in Eastern China. Results showed that trace metals have accumulated in the river sediments during long-term agricultural development, with special concern of Cu, Ni, Pb, and Cr that may pose adverse biological effects. Among them, Pb was the most anthropogenically impacted trace metal due to its high EF value, but its excessive concentration still did not exceed background concentration. Based on the excessive trace metal concentrations, atmospheric deposition, livestock manure, and chemical fertilizer were identified as the three major anthropogenic pollution sources, and their respective contributions were further estimated by using MLR-APCS model. Together with natural contributions, atmospheric deposition contributed on average 35.3%, 43.1%, and 30.4% of total Ni, Pb, and Cr concentrations in the sediments, respectively. Similarly, livestock manure contributed 41.0% of total Cu and 40.6% of total Zn concentrations, while chemical fertilizer was responsible for 44.3% of total Cd concentration. For Pb, the source contribution of atmospheric deposition to sediment pollution was also quantitatively assessed by isotopic analysis, which was generally close to the value of 43.1% and therefore verified the EF and MLR-APCS results.

Microcystis aeruginosa, a species of freshwater cyanobacteria, is known to be one of the dominant species causing cyanobacterial harmful algal blooms (CyanoHABs). M. aeruginosa blooms have the potential to produce neurotoxins and peptide hepatotoxins, such as microcystins and lipopolysaccharides (LPSs). Currently, technologies for CyanoHAB control do not provide any ultimate solution because of the secondary pollution associated with the control measures. In this study, we attempted to use the peptide HPA3NT3-A2, which has been reported to be nontoxic and has antimicrobial properties, for the development of an eco-friendly control against CyanoHABs. HPA3NT3-A2 displayed significant algicidal effects against M. aeruginosa cells. HPA3NT3-A2 induced cell aggregation and flotation (thereby facilitating harvest), inhibited cell growth through sedimentation, and eventually destroyed the cells. HPA3NT3-A2 had no algicidal effect on other microalgal species such as Haematococcus pluvialis and Chlorella vulgaris. Additionally, HPA3NT3-A2 was not toxic to Daphnia magna. The algicidal mechanism of HPA3NT3-A2 was intracellular penetration. The results of this study suggest the novel possibility of controlling CyanoHABs using HPA3NT3-A2.

In this paper, we synthesized a polyglycerol(PG)-mediated superparamagnetic graphene oxide nanocomposite called MGON, consisting of PG-modified superparamagnetic iron oxide nanoparticles (SPION) covalently bonded to PG-functionalized graphene oxide (GO). MGON exhibits better dispersibility and colloidal stability in aqueous solution than the magnetic graphene oxide reported in the literature. The physicochemical properties of MGON were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and UV-vis spectroscopy. Applied to the adsorption of tetracycline (TC) in aqueous solution as an adsorbent, the MGON showed excellent adsorption performance with the maximum adsorption capacity of 684.93 mg/g at 298 K. Adsorption kinetics and isotherm results indicate that the adsorption process conforms to the pseudo-second-order kinetics and Langmuir isotherm models. Adsorption thermodynamics has confirmed that the adsorption process of TC on MGON is spontaneous and endothermic. With the increase of temperature, the adsorption capacity of MGON increases continuously, and the adsorption capacity of MGON is the largest when the pH value is 7. Furthermore, the π-π and cation-π interaction, amidation reaction, and hydrogen bonding can be used to explain the adsorption mechanism of TC on MGON. Desorption and regeneration experiments showed that MGON still had 67.65% regenerative performance after five cycles. Hence, MGON is a promising adsorbent in the removal of tetracycline from wastewater.

This paper explores the impact of shale gas and oil fracking wells on infants’ health at birth across Oklahoma counties. The empirical analysis makes use of the Dumitrescu-Hurlin causality test, as well as the (long-run) Pooled Mean Group method. The results clearly document that there is a unidirectional relationship between fracking activities and three alternative indexes of infants’ health at birth, as well as a significant impact of fracking on infants’ health indicators. In addition, the results illustrate the substantial role of fracking through the drinking water quality channel.

Oxidative stress is an imbalance between free radicals and antioxidants which leads to reactive oxygen species (ROS) production in cells. Reactive oxygen species contains oxygen radicals that easily react with other molecules in the biological system. For decades, lead acetate (Pb(C₂H₃O2)₂) is used as an additive for many widely used chemical products such as insecticides, hair dyes, and cosmetics; however, contact with lead acetate may irritate skin, eyes, and mucous membranes.In the present study, the antioxidant and anti-inflammatory effect of using ferulic acid to inhibit lead acetate-induced toxicity in rats is investigated. Lead acetate was orally given at a dose of 20 mg/kg body weight for 10 days, either alone or with ferulic acid at dose 25 mg/kg. Serum luteinizing hormone (LH), total testosterone, and follicle-stimulating hormone (FSH) levels were measured. Also, reactive oxygen species (ROS), lipid peroxidation (LPO), total antioxidant capacity (TAC), and catalase (CAT) activities were determined. In addition, histopathological changes of testes and kidney were examined. Results showed that administration of lead acetate induced oxidative stress through attenuation of luteinizing hormone, total testosterone, and follicle-stimulating hormone levels in serum. Moreover, the kidney and testes of lead acetate-treated animals exhibited elevation of ROS level, lipid peroxide levels, as well as lysosomal enzyme activity such acid phosphatase and N-acetyl-β-glucosminidase. DNA fragmentation and histological changes were also observed in lead acetate-treated group. In contrast, ferulic acid treatment reduced the deleterious effects induced by lead acetate in both testes and kidney tissues. These results illustrated that ferulic acid has a protective action against toxicity caused by lead acetate in rats. In conclusions, ferulic acid may have future therapeutic relevance in the prevention of lead acetate-induced testicular and renal toxicity in rats.

In recent years, as environmental degradation has become more and more serious, the Chinese government has formulated a series of environmental policies and regulations aimed at improving environmental quality. Does environmental regulation significantly inhibit environmental pollution? Environmental regulation will not only directly affect environmental pollution but also have an indirect impact on environmental pollution. This paper uses Bayesian posterior probability, the optimal model structure selection method, based on join 112 kinds of spatial econometric model structure, and the panel data of 30 provinces in China from 2003 to 2016 to study the effects of environmental regulation on environmental pollution base on the industrial agglomeration mechanism of synergy effect. The research covers the national level and four regions, including the eastern, central, western, and northeastern regions of China. The research shows that: (1) environmental regulation at the national level and in the eastern, central and northeastern regions can significantly curb environmental pollution, but the environmental pollution in the western region shows a significant trend of enhancement. (2) Increased industrial agglomeration across China has significantly worsened environmental pollution. (3) Environmental regulation and industrial agglomeration form a significant synergy effect, which has a significant positive impact on environmental pollution in regions other than northeast China, and a significant negative impact on environmental pollution intensity in northeast China.