Bank filtration (BF) has been employed for more than a century for the production of water with a better quality, and it has been showing satisfactory results in diclofenac attenuation. Considered the most administered analgesic in the world, diclofenac has been frequently detected in water bodies. Besides being persistent in the environment, this compound is not completely removed by the conventional water treatments, drinking water treatment plants (DWTPs) and wastewater treatment plant (WWTPs). BF has a high complexity, whose efficiency depends on the characteristics of the observed pollutant and on the environment where the system in installed, which is why this is a topic that has been constantly studied. Nevertheless, studies present the behavior of diclofenac during the BF process. In this context, this research performed the evaluation of the factors and the biogeochemical processes that influence the efficiency of the BF technique in diclofenac removal. The aerobic conditions, higher temperatures, microbial biomass density, hydrogen potential close to neutrality and sediments with heterogeneous fractions are considered the ideal conditions in the aquifer for diclofenac removal. Nonetheless, there is no consensus on which of these factors has the greatest contribution on the mechanism of attenuation during BF. Studies with columns in laboratory and modeling affirm that the highest degradation rates occur in the first centimeters (5–50 cm) of the passage of water through the porous medium, in the environment known as hyporheic zone, where intense biogeochemical activities occur. Research has shown 100% removal efficiency for diclofenac persistent to compounds not removed during the BF process. However, half of the studies had removal efficiency that ranged between 80 and 100%. Therefore, the performance of more in-depth studies on the degradation and mobility of this compound becomes necessary for a better understanding of the conditions and biogeochemical processes which act in its attenuation.

Numerous epidemiological studies have shown a close relationship between outdoor air pollution and increased risks for cancer, infection, and cardiopulmonary diseases. However, very few studies have investigated the potential health effects of coexposure to airborne particulate matter (PM) and bioaerosols through the transmission of infectious agents, particularly under the current circumstances of the coronavirus disease 2019 pandemic. In this study, we aimed to identify urinary metabolite biomarkers that might serve as clinically predictive or diagnostic standards for relevant diseases in a real-time manner. We performed an unbiased gas/liquid chromatography-mass spectroscopy (GC/LC-MS) approach to detect urinary metabolites in 92 samples from young healthy individuals collected at three different time points after exposure to clean air, polluted ambient, or purified air, as well as two additional time points after air repollution or repurification. Subsequently, we compared the metabolomic profiles between the two time points using an integrated analysis, along with Kyoto Encyclopedia of Genes and Genomes-enriched pathway and time-series analysis. We identified 33 and 155 differential metabolites (DMs) associated with PM and bioaerosol exposure using GC/LC-MS and follow-up analyses, respectively. Our findings suggest that 16-dehydroprogesterone and 4-hydroxyphenylethanol in urine samples may serve as potential biomarkers to predict or diagnose PM- or bioaerosol-related diseases, respectively. The results indicated apparent differences between PM- and bioaerosol-associated DMs at five different time points and revealed dynamic alterations in the urinary metabolic profiles of young healthy humans with cyclic exposure to clean and polluted air environments. Our findings will help in investigating the detrimental health effects of short-term coexposure to airborne PM and bioaerosols in a real-time manner and improve clinically predictive or diagnostic strategies for preventing air pollution-related diseases.

Passivation of soil heavy metals using environmental materials is an important method or important in situ remediation measure. There are more studies on inorganic environmental materials for heavy metal passivation, but not enough studies on organic and their composite environmental materials with inorganic ones. In order to reveal the passivation effect of coal-based ammoniated humic acid (CAHA), biochemical humic acid (BHA), biochar (BC) and other organic types and inorganic environmental materials such as zeolites (ZL) on soil heavy metals and their biological effectiveness. The microstructures of these materials were analyzed by Scanning electron microscope (SEM). The main components of the environmental materials were analyzed by Energy dispersive spectrometer (EDS), Fourier transforms infrared spectroscopy (FT-IR) and X-ray diffraction spectrum (XRD) to elucidate the mechanism of passivation of heavy metals in soil by these environmental materials. The study was conducted to investigate the effects of different types of environmental materials and their combinations on the passivation effect and biological effectiveness of Pb and Cd complex contamination in soil by means of soil incubation and pot experiments using single-factor and multifactor multilevel orthogonal experimental designs. Soil incubation experiments proved that the effective state of soil Pb and Cd in T₇ was reduced by 13.40% and 11.07%, respectively. The extreme difference analysis determined the optimized formulation of soil lead and cadmium passivation as BHA: CAHA: BC: ZL = 3.5:5:20:10. The pot experiment proved that the application of composite environmental materials led to the reduction of lead and cadmium content and increase of biomass of Pak-choi, and the optimal dosage of optimized composite environmental materials was 23.1 g/kg.

Emergency responses to the COVID-19 pandemic led to major changes in travel behaviours and economic activities in 2020. Machine learning provides a reliable approach for assessing the contribution of these changes to air quality. This study investigates impacts of health protection measures upon air pollution and traffic emissions and estimates health and economic impacts arising from these changes during two national ‘lockdown’ periods in Oxford, UK. Air quality improvements were most marked during the first lockdown with reductions in observed NO₂ concentrations of 38% (SD ± 24.0%) at roadside and 17% (SD ± 5.4%) at urban background locations. Observed changes in PM₂.₅, PM₁₀ and O₃ concentrations were not significant during first or second lockdown. Deweathering and detrending analyses revealed a 22% (SD ± 4.4%) reduction in roadside NO₂ and 2% (SD ± 7.1%) at urban background with no significant changes in the second lockdown. Deweathered-detrended PM₂.₅ and O₃ concentration changes were not significant, but PM₁₀ increased in the second lockdown only. City centre traffic volume reduced by 69% and 38% in the first and second lockdown periods. Buses and passenger cars were the major contributors to NO₂ emissions, with relative reductions of 56% and 77% respectively during the first lockdown, and less pronounced changes in the second lockdown. While car and bus NO₂ emissions decreased during both lockdown periods, the overall contribution from buses increased relative to cars in the second lockdown. Sustained NO₂ emissions reduction consistent with the first lockdown could prevent 48 lost life-years among the city population, with economic benefits of up to £2.5 million. Our findings highlight the critical importance of decoupling emissions changes from meteorological influences to avoid overestimation of lockdown impacts and indicate targeted emissions control measures will be the most effective strategy for achieving air quality and public health benefits in this setting.

Biochar was prepared from rice straw and modified with 15% H₂O₂ and 1:1 HNO₃/H₂SO₄, respectively. The unmodified biochars and HCl treated biochars for carbonate removal were used as control. The biochars were added to the acid paddy soil collected from Langxi, Anhui Province, China at the rate of 30 g/kg. The paddy soil was flooded and then air-dried, and soil pH and Eh were measured in situ with pH electrode and platinum electrode during wet-dry alternation. Soil pH buffering capacity (pHBC) was determined by acid-base titration after the wet-dry treatment. Then, the simulated acidification experiments were carried out to study the changing trends of soil pH, base cations and exchangeable acidity. The results showed that soil pHBC was effectively increased and the resistance of the paddy soil to acidification was apparently enhanced with the incorporation of H₂O₂- and HNO₃/H₂SO₄-modified biochars. Surface functional groups on biochars were mainly responsible for enhanced soil resistance to acidification. During soil acidification, the protonation of organic anions generated by dissociation of these functional groups effectively retarded the decline of soil pH. The modification of HNO₃/H₂SO₄ led to greater increase in carboxyl functional groups on the biochars than H₂O₂ modification and thus HNO₃/H₂SO₄-modified biochars showed more enhancement in soil resistance to acidification than H₂O₂-modified biochars. After a wet-dry cycle, the pH of the paddy soil incorporated with HNO₃/H₂SO₄-modified biochar increased apparently. Consequently, the addition of HNO₃/H₂SO₄-modified biochar can be regarded as a new method to alleviate soil acidification. In short, the meaning of this paper is to provide a new method for the amelioration of acid paddy soils.

The impact of CeO₂ nanoparticles (NPs) on plant physiology and soil microcosm and the underlying mechanism remains unclear to date. This study investigates the effect of CeO₂ NPs on plant growth and soil microbial communities in both the rhizosphere of cucumber seedlings and the surrounding bulk soil, with CeCl₃ as a comparison to identify the contribution of the particulate and ionic form to the phytotoxicity of CeO₂ NPs. The results show that Ce was significantly accumulated in the cucumber tissue after CeO₂ NPs exposure. In the roots, 5.3% of the accumulated Ce has transformed to Ce³⁺. This transformation might take place prior to uptake by the roots since 2.5% of CeO₂ NPs was found transformed in the rhizosphere soil. However, the transformation of CeO₂ NPs in the bulk soil was negligible, indicating the critical role of rhizosphere chemistry in the transformation. CeO₂ NPs treatment induced oxidative stress in the roots, but the biomass of the roots was significantly increased, although the Vitamin C (Vc) content and soluble sugar content were decreased and mineral nutrient contents were altered. The soil enzymatic activity and the microbial community in both rhizosphere and bulk soil samples were altered, with rhizosphere soil showing more prominent changes. CeCl₃ treatment induced similar effects although less than CeO₂ NPs, suggesting that Ce³⁺ released from CeO₂ NPs contributed to the CeO₂ NPs induced impacts on soil health and plant physiology.

Eutrophication is an important water environment issue facing global lakes. Diversion of water from external watersheds into lakes is considered as effective in ameliorating eutrophication and reducing algal blooms. Nevertheless, the changes in lake water environment caused by external water diversion, especially the influence of water diversion on the characteristics of dissolved organic matters (DOM), are still poorly understood. We therefore used a combination of EEM-PARAFAC, Principal Component Analysis (PCA), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to investigate the effects of water diversion from the Niulan River on DOM characteristics in Lake Dianchi. The results showed that the water diversion from the Niulan River significantly improved the water quality of Lake Dianchi, the concentrations of TN, TP, COD and Chla decreased rapidly, and the degree of humification of dissolved organic matter (DOM) increased, which was in sharp contrast with that of pre-implementation. Firstly, the diversion of water from the Niulan River mainly led to changes in the structure of pollution sources. The load of influent rivers and sewage treatment plants rich in lignin and tannins increased, and the input of terrestrial humus increased. Second, the improved water quality reduced algal enrichment and frequency of blooms, and reduced the release of lipid- and protein-riched algal-derived DOM. Finally, the hydraulic retention time of Lake Dianchi caused by water diversion was shortened, the hydrodynamic conditions were significantly improved, and the dissolved oxygen (DO) level gradually recovered, which played a positive role in improving the humification degree of DOM. Our findings provide new insights for exploring the improvement of eutrophic lake eco-environmental quality caused by water diversion projects.

There is little information available to decipher the interaction between molybdenum (Mo) and nitric oxide (NO) in mitigating arsenic (Asⱽ) stress in plants. The present work highlights the associative role of exogenous Mo and endogenous NO signaling in regulating Asⱽ tolerance in wheat seedlings. Application of Mo (1 μM) on 25-day-old wheat seedlings grown in the presence (5 μM) or absence of Asⱽ stress caused improvement of photosynthetic pigment metabolism, reduction of electrolytic leakage and reactive oxygen species (ROS), and higher accumulation of osmolytes (proline and total soluble sugars). The molybdenum treatment upregulated antioxidative enzymes, such as superoxide dismutase, ascorbate peroxidase and glutathione reductase. In addition, the accumulation of nonenzymatic antioxidants (ascorbate and glutathione) was correlated with an increase in ascorbate peroxidase and glutathione reductase activity. The application of cPTIO (endogenous NO scavenger; 100 μM) reversed the Mo-mediated effects, thus indicating that endogenous NO may accompany Mo-induced mitigation of Asⱽ stress. Mo treatment stimulated the accumulation of endogenous NO in the presence of Asⱽ stress. Thus, it is evident that Mo and NO-mediated Asⱽ stress tolerance in wheat seedlings are primarily operative through chlorophyll restoration, osmolytes accumulation, reduced electrolytic leakage, and ROS homeostasis.

Pesticide contamination is a threat to many aquatic habitats, and runoff from residential homes is a major contributor of these chemicals in urban surface streams and estuaries. Improved understanding of their fate and transport can help identify areas of concern for monitoring and management. In many urban areas, runoff water congregates in numerous underground catch basins before draining into the open environment; however, at present essentially no information is available on pesticide presence in these systems. In this study, we collected water samples from a large number of underground urban catch basins in different regions of California during the active pest management season to determine the occurrence and profile of the widely used pyrethroid insecticides. Detectable levels of pyrethroids were found in 98% of the samples, and the detection frequency of individual pyrethroids ranged from no detection for fenpropathrin to 97% for bifenthrin. In the aqueous phase, total pyrethroid concentrations ranged from 3 to 726 ng/L, with a median value of 32 ng/L. Pyrethroids were found to be enriched on suspended solids, with total concentrations ranging from 42 to 93,600 ng/g and a median value of 2,350 ng/g. In approximately 89% of the samples, whole water concentrations of bifenthrin were predicted to have toxic units >1 for sensitive aquatic invertebrates. The high detection frequency of bifenthrin and overall pyrethroid concentrations, especially for particle-bound residues, suggest that underground urban catch basins constitute an important secondary source for extended and widespread contamination of downstream surface waters by pesticides such as pyrethroids in urban regions.

Biochemical oxidation and reduction are key processes in treating biological wastewater and they require the presence of electron acceptors. The functional impact of electron acceptors on microbiomes provides strategies for improving the treatment efficiency. This research focused on two of the most important electron acceptors, nitrate and oxygen. Molecule ecological network, null model, and functional prediction based on high-throughput sequencing were used to analyze the microbiomes features and assembly mechanism. The results revealed nitrate via the homogeneous selection (74.0%) decreased species diversity, while oxygen via the homogeneous selection (51.1%) and dispersal limitation (29.6%) increased the complexity of community structure. Microbes that were more strongly homogeneously selected for assembly included polyphosphate accumulating organisms (PAOs), such as Pseudomonas and variovorax in the nitrate impacted community; Pseudomonas, Candidatus_Accumulibacter, Thermomonas and Dechloromonas, in the oxygen impacted community. Nitrate simplified species interaction and increased the abundance of functional genes involving in tricarboxylic acid cycle (TCA cycle), electron transfer, nitrogen metabolism, and membrane transport. These findings contribute to our knowledge of assembly process and interactions among microorganisms and lay a theoretical basis for future microbial regulation strategies in wastewater treatment.