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.

Environmental waters cover a range of water quality characteristics which could greatly affect the behavior and fate of C₆₀ in the aquatic environment. In this study, the dispersion and stability of C₆₀ in several environmental water matrices during a 70-day extended mixing period were investigated to better understand its environmental behavior and fate in environmental waters. Relatively stable nanoscale aggregates in water (aqu/nC₆₀) could be formed in wastewater influent, while unstable suspensions were obtained in river water, wastewater effluent, seawater, and estuarine water. During the extended mixing under sunlight, oxygen-containing moieties were produced on the surface of the C₆₀ aggregates, independent of the kind of environmental water matrices. Once the mixed system went under quiescent condition, aggregation and sedimentation of aqu/nC₆₀ occurred. However, an extremely short-time disturbance could easily resuspend the C₆₀ aggregates deposited and increase the concentration of aqu/nC₆₀ in the overlying water column. Therefore, the effects of resuspension should be considered when investigating the environmental behavior and fate of C₆₀.

Poor removal of many pharmaceuticals and personal care products in sewage treatment plants leads to their discharge into the receiving waters, where they may cause negative effects for aquatic environment and organisms. In this study, electrochemical removal process has been used as alternative method for removal of mefenamic acid (MEF). For our knowledge, removal of MEF using electrochemical process has not been reported yet. Effects of initial concentration of mefenamic acid, sodium chloride (NaCl), and applied voltage were evaluated for improvement of the efficiency of electrochemical treatment process and to understand how much electric energy was consumed in this process. Removal percentage (R%) was ranged between 44 and 97%, depending on the operating parameters except for 0.1 g NaCl which was 9.1%. Consumption energy was 0.224 Wh/mg after 50 min at 2 mg/L of mefenamic acid, 0.5 g NaCl, and 5 V. High consumption energy (0.433 Wh/mg) was observed using high applied voltage of 7 V. Investigation and elucidation of the transformation products were provided by Bruker software dataAnalysis using liquid chromatography-time of flight mass spectrometry. Seven chlorinated and two non-chlorinated transformation products were investigated after 20 min of electrochemical treatment. However, all transformation products (TPs) were eliminated after 140 min. For the assessment of the toxicity, it was impacted by the formation of transformation products especially between 20 and 60 min then the inhibition percentage of E. coli bacteria was decreased after 80 min to be the lowest value.

Solid waste fly ash with low aluminum of Yunnan Province in China was used as pristine material to prepared chitosan-coated Na–X zeolite, and the obtained composite material was employed as As(V) adsorbent. Then, the prepared materials were characterized by XRD, FT-IR, and XPS. And the results suggested that the low aluminum fly ash was successfully convert into Na–X zeolite, and the mineralization between Si–OH of the obtained Na–X zeolite and C–OH of chitosan was the dominated mechanism for coated chitosan over the surface of Na–X zeolite. From the batch experiments of As(V) removal, it has been found that the coated chitosan could significantly improve As(V) performance of Na–X zeolite. The optimal working pH for removal As(V) by chitosan-coated Na–X zeolite was attained at pH 2.1 ± 0.1, and the maximum adsorption capacity was 63.23 mg/g. And the adsorption data at different interval time was excellent fitted by pseudo-second-order kinetic model. From the analyze of XPS, the results suggested that As(V) uptake over adsorbent by the bond of As–N and As–O and the surface hydroxyl group of Al–OH and –NH₂ were involved in uptake As(V) from acid wastewater.

Phytoremediation combined with amendments and stabilization technologies are two crucial methods to deal with soil contaminated with heavy metals. Copper (Cu) contamination in soil near Cu mines poses a serious threat to ecosystems and human health. This study investigated the effect of ethylenediaminetetraacetic acid (EDTA) and biochar (BC) on the accumulation and subcellular distribution of Cu in Amaranthus retroflexus L. to demonstrate the remediation mechanism of EDTA and BC at the cellular level. The role of calcium (Ca) in response to Cu stress in A. retroflexus was also elucidated. We designed a pot experiment with a randomized block of four Cu levels (0, 100, 200, 400 mg kg⁻¹) and three treatments (control, amendment with EDTA, and amendment with BC). The subcellular components were divided into three parts (cell walls, organelles, and soluble fraction) by differential centrifugation. The results showed that EDTA amendment significantly increased (p < 0.05) the concentrations of Cu in root cell walls and all subcellular components of stems and leaves (cell walls, organelles, and the soluble fraction). EDTA amendment significantly increased (p < 0.05) the proportion of exchangeable fraction and carbonate fraction in the soil. While BC amendment significantly decreased (p < 0.05) the concentrations of Cu in root cell walls and the root soluble fraction, it had no significant effects on Cu concentrations in the subcellular components of stems and leaves. The results revealed that EDTA mainly promoted the transfer of Cu to aboveground parts and accumulation in subcellular components of stems and leaves, while BC mainly limited Cu accumulation in root cell walls and the root soluble fraction. Ca concentrations in cell walls of roots, stems, and leaves increased as the Cu stress increased in all treatment groups, indicating that Ca plays an important role in relieving Cu toxicity in Amaranthus retroflexus L.