Vanadium (V) has been progressively studied due to its potential toxicity in the environment as a trace metal. A coexistence system of humic acid (HA) and silica was employed to simulate the main organic and inorganic components of soil. The adsorption and desorption characteristics of V by the system and the effects of several environmental conditions were investigated. The adsorption data were well described by the Langmuir and Freundlich models, illustrating that the adsorption of V on HA + silica was a monolayer adsorption. The kinetic study indicated that the main adsorption controlling step was a chemical reaction. The thermodynamic study showed that the adsorption was exothermic and spontaneous. The adsorption-desorption process was strongly dependent on the solution pH and HA concentration, while temperature (4–75 °C) and ionic strength (< 1 mol L⁻¹) showed limited effect on overall adsorption performances. In general, the results revealed a considerable V fixation ability of HA-silica coexistence system. The mobility and bioavailability of V in soil was effectively reduced by coexisting HA and silica.

17β-Estradiol (E2) is one of the main compounds responsible for estrogenic activities in sewage and natural waters and has been found in these matrices all around the world, thereby justifying the development of technologies for its removal. In this work, pure or TiO₂-containing molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were prepared using E2 as template. The materials were characterized by infrared spectroscopy, X-ray diffraction, adsorption/desorption of N₂, and scanning electron microscopy (SEM). The characterization analyses showed that TiO₂ was incorporated in the polymers and that all materials could be characterized as mesoporous and had surface areas ranging from 238 to 279 m²g⁻¹. Adsorption studies showed MIP-TiO₂ had a high capacity to adsorb E2 from the water phase leading to qₘₐₓ values of 15.16 to 26.49 mg g⁻¹ at temperatures from 25 to 45 °C, respectively. In addition, the thermodynamic study showed that the adsorption process is endothermic, spontaneous, and entropically driven. The results also showed that the presence of TiO₂ decreases the adsorption performance of MIP-TiO₂ when compared with MIP (without the photocatalyst) during the adsorption. However, the application of MIP-TiO₂ in a process of adsorption followed by photocatalysis resulted in 100% of E2 removal allowing the reuse of adsorbent. In addition, MIP-TiO₂ maintained its E2 removal capacity even after five cycles of regeneration–reuse, which shows the ability of UV light to regenerate the specific adsorption sites. The results presented in this paper show MIP-TiO₂ has potential to be applied in water treatment systems to remove E2.

Water pollution is exacerbated due to irrational human activities in China. Restoring and rebuilding river basin ecosystems are major ecological strategies at present. Controlling the non-point source pollution (NPSP) by reasonable management of land use in the basin and phytoremediation of contaminated waters is the optimum approach. Thus, it is significant to study on the relationship that between landscape change and the aquatic environment, as well as further to analyze on the combined effect of the landscape and water quality. This paper describes the application and development of the “source–sink” landscape theory in China, and the role of the theory in controlling NPSP. From this perspective, a landscape capable of generating NPSP would be a “source” landscape, such as farmland, while another capable of preventing NPSP would be a “sink” landscape, such as forests and wetland. Applying the source-sink landscape theory, it is possible to exert the ecological benefits of the landscape while playing the esthetic value of the landscape. Also, the purification mechanism of plants in contaminated water is discussed. Besides, it is vital that research on water body restoration should focus not only on single discipline but also on integration and coordination between various ones such as ecology, environmental science, and geography to jointly push up researches related to water body phytoremediation. Hopefully, this paper could help to control water pollution from a new perspective, also to improve water environment and benefit human lives.

The effects of microplastic exposure in aquatic organisms have been widely reported. Nonetheless, there is limited evidence of the effects of exposure in soil systems. Thus, the objective of this study was to evaluate the effects of microplastic exposure using as a bioindicator the species Lumbricus terrestris, exposed to different concentrations of microplastic (2.5%; 5%, and 7% w/w). Avoidance bioassays were carried out for 48 h in soil with and without microplastic; the gastrointestinal tract—crop/gizzard, foregut, and midgut—was dissected and acetylcholinesterase (AChE) was used as a biomarker of neurotoxicity stress. In parallel, bioassays of microplastic ingestion were carried out, and after 48 h of initiating the ingestion assay, using a stereo and fluorescence microscope, the microplastic distribution was observed in the different earthworm segments. The results obtained in the avoidance assay indicated a lack of preference for either soil type; however, upon moving, the earthworms lost surface mucus, resulting in burns and lesions on their bodies, which were reflected in the increase in AChE enzyme levels, which was not directly related to microplastic ingestion, but rather likely acts as an external physical stress agent. The results of the ingestion bioassay showed that microplastic was present in all the earthworm segments, with a higher number of particles in the hindgut. The Lumbricus terrestris did not distinguish microplastics from soil particles, and given the high exposure concentrations, microplastics produced physical lesions on the mucus membranes of earthworms. Lumbricus terrestris showed to be a suitable bioindicator for testing the exposure to microplastic contamination in soil.

Tidal groundwater dynamics and hydrochemistry can play important roles in influencing nearshore ecological and environmental systems. However, the potential relationship between the groundwater dynamics and the hydrochemical characteristics was not well understood. In this study, we conducted an integrated investigation by field work and numerical simulations to explore the potential effect of tidal groundwater dynamics on hydrochemistry in an intertidal mudflat in Daya Bay, China. The time series of groundwater level were monitored over a spring-neap tidal cycle along a 200-m-long intertidal transect, which had a mud-sand-layered aquifer. The shallow groundwater samples were collected to analyze the spatial distributions of hydrochemical characteristics, including major ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄²⁻, HCO₃⁻, and Cl⁻), heavy metals (As and Cu), and short-lived radium isotopes (²²³Ra and ²²⁴Ra). The groundwater transport process along the transect was simulated for understanding the groundwater flow field and quantifying the groundwater-seawater exchange rates across the water-sediment interface. The integrated results indicated that the seawater-groundwater interactions play a great influence on the groundwater hydrochemistry. For example, the major ions showed various degrees of enrichment and loss, such as losses of SO₄²⁻ due to microbial sulfate reduction, and enrichment of HCO₃⁻, Ca²⁺, and Mg²⁺ under the water-rock interactions. Heavy metals were transported by groundwater and accumulated in the intertidal sediments. In addition, there was a negative correlation between short-lived radium isotope activities and oxidation-reduction potential. However, the relationship between seawater-groundwater exchange rates and the short-lived radium isotope activities was not significant.

Under natural conditions, the dissolved inorganic carbon (DIC) in river water is dominantly derived from carbonate or silicate dissolution by carbonic acid. However, sulfuric and nitric acids produced by human activities provide additional acidity for chemical weathering, which would affect the DIC flux and change its isotopic composition. To identify the natural and anthropogenic impacts on DIC, the major ion concentrations and stable carbon isotopes of the DIC (δ¹³C-DIC) of river waters were measured in the Pearl River Delta (PRD) region, which is one of the most developed and populated areas in China. The mass balance calculations for DIC-apportionment showed that carbonate dissolution by carbonic acid was the dominant origin of DIC in the Beijiang (BJ) River (67%) and Xijiang (XJ) River (78%) and silicate dissolution by carbonic acid was the dominant origin of DIC in the Guangzhou (GZ) Channel (37%) and Dongjiang (DJ) River (50%), which was related to the lithology of the catchment. The contribution of carbonate dissolution by sulfuric and nitric acids, which represented the contribution of human activities to the total DIC concentrations in river water, showed high proportions in the GZ Channel and DJ River, with averages of 42% and 34%, respectively, which were associated with a high degree of urbanization. Evidence of hydrochemical parameters and δ¹³C-DIC signatures indicated that human activities had impacts on the DIC pool. Carbonate dissolution by sulfuric and nitric acids caused by human activities changed DIC apportionments rather than the DIC flux, and this part of DIC would ultimately become a source of CO₂ to the atmosphere on the geological timescale and affects the CO₂ budget. An increase in nutrient concentration due to increased sewage discharge in the urbanized area could promote phytoplankton photosynthesis, which could change the DIC pool and increase the δ¹³C-DIC value. This study quantitatively highlights the influence of human activities on DIC apportionment in river water, suggesting that anthropogenic impacts should be seriously considered when evaluating the evolution of DIC.

Increasing the uses of molybdenum (Mo) nanoparticles in a wide range of applications including food, industry, and medicine, resulted in increased human exposure and necessitated the study of their toxic effects. However, almost no studies are available on their genotoxic effects, especially on pregnant females and their fetuses. Therefore, this study was undertaken to estimate the possible induction of genotoxicity and fetal abnormalities, especially fetal malformations and skeletal abnormalities by Mo nanoparticle administration in mice. Oral administration of Mo nanoparticles resulted in significant decreases in the maternal body weight, the number and length of fetuses as well as skeletal abnormalities mainly less ossification and less chondrification. Administration of Mo nanoparticles also caused DNA damage induction which elevated the expression levels of p53, the vital gene in maintaining the genomic stability and cell differentiation in both maternal and fetus tissues. Similarly, the expression levels of E-Cad and N-Cad genes that control skeleton development have also been increased in the tissues of female mice administered Mo nanoparticles and their fetuses. Thus, we concluded that oral administration of Mo nanoparticles induced genotoxic effects and fetal abnormalities that necessitated further studies on the possible toxic effects of Mo nanoparticles.

Amendment with treated biosolids can increase soil fertility and plant nutrition to the soil, but the fertilization value compared with other commercial soil amendments on the soil ecosystem is poorly understood. The effects of different proportions (0%, 5%, 10%, and 15%) of thermal and pH-treated biosolid applications on the growth performance, nutrient contents, and toxicity performance of carrots (Daucus carota L.) and choy sum (Brassica chinensis var. parachinensis) were studied. Different commercial organic soil amendments, such as biochar, chicken manure (CM), and food waste compost (FWC), were also used as a comparison in the experiment to determine the feasibility of biosolid application on agricultural use. All four soil amendments resulted in similar growth trends for the carrots and choy sum, and this information can be applied in selecting the appropriate species of plants. Through thermal and pH treatments, the treated biosolids decreased environmental risks and resulted in higher amounts of N and P in comparison to the other soil amendments. The results showed that 10% biosolid-amended soil performed best in terms of plant growth, biomass, and nutrient content for both carrots and choy sum. Nutrient analysis (N, P, and K) and heavy metal analysis (As, Cd, and Pb) on both soil and plants were conducted. It was proven that biosolid application was as functional as CM application and could be used as organic fertilizer to replace biochar and FWC for agricultural use. No heavy metals were found in the pure biosolids, which were safe to use as fertilizers. Utilizing biosolids as fertilizers could be an effective way to address the problem of waste disposal and landfill loading for the environment.

This study focuses on the synthesis of carbon nanotubes decorated with nickel-zinc ferrites and fabrication of polyurethane (PU) nanofiber containing CNT-ferrite composites as highly efficient adsorbents for removal of hydrogen sulfide. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transformed infrared (FTIR) spectroscopy, and powder X-ray diffraction (PXRD) are used to perform microstructural and morphological characterization of the electrospun nanofibrous composites. To show the efficiency of the composite as an adsorbent, a breakthrough test is carried out. It is shown that the PU-CNT-ferrite composites are fabricated almost uniformly with an average fiber diameter of 320 nm and exhibit significant H₂S breakthrough capacity (498 mgH₂S/g) compared to both the pristine PU and PU-CNT nanofibers. These electrospun nanofibers based on CNT-ferrite composites, already studied for H₂S adsorption with promising results, open up new and interesting perspective into the design and fabrication of highly efficient membrane for practical application in the processes of air purification.