Iron (III) co-precipitation with dissolved organic matter (DOM) is pervasive in many natural environments. However, the effects of DOM on the formation of Fe(III) hydroxysulfate (FHS) and its environmental implications are poorly understood. In this study, fulvic acid (FA) was used as a model DOM compound, and experiments were devised to investigate the effects of FA on the formation of FHS. In addition, the Pb(II) adsorption capabilities of FHSs biosynthesized under various FA dosages, including kinetics and sorption isotherm experiments, were conducted. These experiments showed that co-precipitation of FA promoted the formation of Fe-FA composites, FA-doped schwertmannite, and small particles of jarosite. Co-precipitates are more enriched in carboxyl (–COOH) functional groups due to their preferential binding with FHS. The adsorption kinetics, isotherms and mechanisms of Pb onto the biosynthesized FHSs were then comprehensively characterized and modeled. Though the specific surface area decreased with increasing FA loading, the introduction of FA into FHSs increased Pb(II) adsorption, with the highest concentration of FA addition improving the removal capacity of Pb(II) to 91.54%. Kinetics studies and intra-particle diffusion models indicated that the adsorption of Pb(II) onto the FHSs was correlated with the number of active sites, and two adsorption steps: surface adsorption and the diffusion of Pb(II) in channels inside the biosynthesized FHSs, are suggested. The adsorption mechanism was attributed to cation exchange between Pb(II) and –OH and –COOH functional groups, and the co-precipitated FA provided additional sites for Pb(II) adsorption by FHS.

The long-term groundwater contamination risks posed by steroidal estrogens (SEs) in animal-manured agricultural soils are closely associated with the soil organic matter (SOM) content and composition. In this study, the bioavailability of estrone (E1) and 17β-estradiol (17β-E2) under different sorption mechanism in humic acids (HA1 and HA2) and humin (HM) extracted with sequential alkaline-extraction technique (SAET) were examined. These SOMs extracted by SAET showed various properties and sorption characteristics for SEs. The alkyl carbon and condensed SOM increased during SAET, but aromatic carbon decreased and the same trend for polarity. Quick sorption was the major SEs sorption mechanism on HA1 and HA2, which contributed more than 69%; whilst slow sorption rate was about 50% in soil and HM. The logKₒc values were proportional to the TOC of SOM according to Freundlich fitting, and the sorption capacity of sorbent for E1 and 17β-E2 was related to the logKₒw values, indicating that the main mechanism controlling the SEs sorption was hydrophobic interaction. The larger micropore volume of HM and soil was more conducive to the micropore filling of SEs. Meanwhile, the specific sorption of SEs on condensed domain of SOM was the main reason for the strong desorption hysteresis and slow sorption in HM and soil. The SEs degradation rate was positively correlated with the contribution rate of quick adsorption and negatively correlated with the contribution rate of slow adsorption, indicating that the bioavailability of SEs sorbed by hydrophobic interaction was higher than that of micropore filling or specific sorption, which was also the reason for the low bioavailability of SEs in HM and soil. This work confirms the regulation of on-site SOM compositions and their properties on SEs sorption and bioavailability. Characterization of these details is crucial for the improved prediction of long-term risks to groundwater.

The widespread presence and persistence of perfluorooctane sulfonate (PFOS) in wastewater treatment plants, as well as its toxicity and bioaccumulation potential, necessitates the investigation on their impact on bioreactor performance. A 48-day exposure test was adopted to study the effects of low (10 μg L-1) and high (1000 μg L-1) PFOS concentrations in a sequencing batch reactor on the performance, composition, and microbial community of activated sludge. The results suggested that adding PFOS at low and high concentrations lowered the removal efficiency of total nitrogen by 22.48% (p < 0.01) and 16.30% (p < 0.01) respectively, while enhanced that of total phosphorus by 1.87% (p > 0.05) and 7.07% (p < 0.05) respectively, compared with the control group. The addition of PFOS also led to the deterioration of activated sludge dewatering performance. Composition and spectroscopic measurements revealed that the PFOS dosage changed the composition of the activated sludge. Furthermore, the PFOS altered the structure and function of the activated sludge microbial community as well as key enzyme activities.

The oceanic production and release of volatile halocarbons (VHCs) to the atmosphere play a vital role in regulating the global climate. In this study, seasonal and spatial variations in VHCs, including trichlorofluoromethane (CFC-11), methyl iodide (CH₃I), dibromomethane (CH₂Br₂), and bromoform (CHBr₃), and environmental parameters affecting their concentrations were characterized in the atmosphere and seawater of the Yangtze River Estuary and its adjacent marine area during two cruises from October 17 to October 26, 2019 and from May 12 to May 25, 2020. Significant seasonal variations were observed in the atmosphere and seawater because of seasonal differences in the prevalent monsoon, water mass (Yangtze River Diluted Water), and biogenic production. VHCs concentrations were positively correlated with Chl-a concentrations in the surface water during autumn. The average sea-to-air fluxes of CH₃I, CH₂Br₂, and CHBr₃ in autumn were 19.7, 4.0, and 7.6 nmol m⁻² d⁻¹, respectively, while those in spring were 6.3, 6.4, and −3.6 nmol m⁻² d⁻¹. In the ship-based incubation experiments, ocean acidification and dust deposition had no significant effects on VHCs concentrations. The concentrations of CH₂Br₂ and CHBr₃ were significantly positively correlated with phytoplankton biomass under lower pH condition (M3: pH 7.9). This result indicated that CH₂Br₂ and CHBr₃ concentrations were mainly related to the biological release.

In this study the persistence (based on extractable, Cₜₒₜ) and bioavailability (based on freely dissolved content, Cfᵣₑₑ) of polycyclic aromatic hydrocarbons (PAHs) in biochar-amended soil was investigated. Biochar produced at 500 or 700 °C from sewage sludge (BC) or sewage sludge and willow (W) mixture (BCW) in an atmosphere of nitrogen (N₂) or carbon dioxide (CO₂) was evaluated. The biochars were applied to the real soil (podzolic loamy sand) at a dose of 2% (w/w). The content of Cₜₒₜ and Cfᵣₑₑ PAHs was monitored for 180 days. The biochar production conditions determined the Cₜₒₜ and Cfᵣₑₑ PAHs in the soil. A change of carrier gas from N₂ to CO₂ caused an increase in Cₜₒₜ PAH losses in the soil from 19 to 75% for the biochar produced from SL and from 49 to 206% for the co-pyrolyzed biochar. As regards Cfᵣₑₑ PAHs, the change from N₂ to CO₂ increased the losses of Cfᵣₑₑ PAHs only for the biochar derived from SL at a temperature of 500 °C (by 21%). In the soil with the other biochars (produced at 700 °C from SL as well as at 500 and 700 °C from SL/W), the Cfᵣₑₑ increased from 17 to 26% compared to the same biochars produced in an atmosphere of N₂.

Ice is an important physical and chemical sink for various pollutants in cold regions. The photodegradation of emerging fluoroquinolone (FQ) antibiotic contaminants with dissolved organic matter (DOM) in ice remains poorly understood. Here, the photodegradation of ciprofloxacin (CIP) and fulvic acid (FA) in different proportions as representative FQ and DOM in ice were investigated. Results suggested that the photodegradation rate constant of CIP in ice was 1.9 times higher than that in water. When CFA/CCIP ≤ 60, promotion was caused by FA sensitization. FA increased the formation rate of cleavage in the piperazine ring and defluorination products. When 60 < CFA/CCIP < 650, the effect of FA on CIP changed from promoting to inhibiting. When 650 ≤ CFA/CCIP ≤ 2600, inhibition was caused by both quenching effects of 143.9%–51.3% and light screening effects of 0%–48.7%. FA inhibited cleavage in the piperazine ring for CIP by the scavenging reaction intermediate of aniline radical cation in ice. When CFA/CCIP > 2600, the light screening effect was greater than the quenching effect. This work provides new insights into how DOM affects the FQ photodegradation with different concentration proportions, which is beneficial for understanding the environmental behaviors of fluorinated pharmaceuticals in cold regions.

Agriculture is one of the foremost significant human activities, which symbolizes the key source for food, fuel and fibers. This activity results in a lot of ecological harms particularly with the excessive usage of chemical fertilizers and pesticides. Different agricultural practices have remained industrialized to advance food production, due to the growth in the world population and to meet the food demand through the routine use of more effective fertilizers and pesticides. Soil is intensely embellished by environmental contamination and it can be stated as “universal incline.” Soil pollution usually occurs from sewage wastes, accidental discharges or as byproducts of chemical residues of unrestrained production of numerous materials. Soil pollution with hazardous materials alters the physical, chemical, and biological properties, causing undesirable changes in soil fertility and ecosystem. Engineered nanomaterials offer various solutions for remediation of contaminated soils. Engineered nanomaterial-enable technologies are able to prevent the uncontrolled release of harmful materials into the environment along with capabilities to combat soil and groundwater borne pollutants. Currently, nanobiotechnology signifies a hopeful attitude to advance agronomic production and remediate polluted soils. Studies have outlined the way of nanomaterial applications to restore the eminence of the environment and assist the detection of polluted sites, along with potential remedies. This review focuses on the latest developments in agricultural nanobiotechnology and the tools developed to combat soil or land and or terrestrial pollution, as well as the benefits of using these tools to increase soil fertility and reduce potential toxicity.

Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most popular and frequently consumed leafy vegetables. It was found that atmospheric PM₂.₅-Pb contributes to Pb accumulation in the edible leaves of Chinese cabbage via stomata in North China during haze seasons with high concentrations of fine particulate matter in autumn and winter. However, it is unclear whether both stomata and trichomes co-regulate foliar transfer of PM₂.₅-Pb from atmospheric deposition to the leaf of Chinese cabbage genotypes with trichomes. Field and hydroponic experiments were conducted to investigate the effects of foliar uptake of PM₂.₅-Pb on Pb accumulation in leaves using two genotypes of Chinese cabbage, one without trichomes and one with trichomes. It was verified that open stoma is a prominent pathway of foliar PM₂.₅-Pb transfer in the short-term exposure for 6 h, contributing 74.5% of Pb accumulation in leaves, whereas Pb concentrations in the leaves of with-trichome genotype in the rosette stage were 6.52- and 1.04-fold higher than that of without-trichome genotype in greenhouse and open field, respectively, which suggests that stomata and trichomes co-regulate foliar Pb uptake of from atmospheric PM₂.₅. Moreover, subcellular Pb in the leaves was distributed in the following order of cytoplasm (53.8%) > cell wall (38.5%)> organelle (7.8%), as confirmed through high-resolution secondary ion mass spectrometry (NanoSIMS). The Leadmium™ Green AM dye manifested that Pb in PM₂.₅ entered cellular space of trichomes and accumulated in the basal compartment, enhancing foliar Pb uptake in the edible leaves of cabbage. The results of these experiments are evidence that both stomata and trichomes are important pathways in the regulation of foliar Pb uptake and translocation in Chinese cabbage.