Understanding the pivotal role of ubiquitous Yellow River suspend sediment in efficiently degrading metronidazole pollutants in water environments.

Sulfite-based advanced oxidation technology has received considerable attention for its application in organic pollutants elimination. However, the potential of natural sediments as effective catalysts for sulfite activation has been overlooked. This study investigates a novel process utilizing suspended sediment/sulfite (SS/S(IV)) for degradation of metronidazole (MNZ). Our results demonstrate that MNZ degradation efficiency can reach to 93.1 % within 90 min with 12.0 g SS and 2.0 mM sulfite. The influencing environmental factors, including initial pH, SS dosage, S(IV) concentration, temperature, and co-existing substances were systematically investigated. Quenching experiments and electron paramagnetic resonance analyses results indicate that SO3•- is the primary active substance responsible for MNZ degradation, with involvement of SO4•-, SO5•-, and •OH. X-ray photoelectron spectroscopy and Mössbauer spectra reveal that Fe (III)-silicates play a crucial role in activating S(IV). Furthermore, analysis of degradation intermediates and pathways of MNZ is conducted using liquid chromatography with mass spectrometry (LC -MS). The toxicity of MNZ and its intermediates were also systematically evaluated by the T.E.ST. program and wheat seeds germination test. This study offers valuable insight into the activation of sulfite by natural sediments and could contribute to the development of SS-based advanced oxidation processes (AOPs) for the in-situ remediation of antibiotics-contaminated water environments.

The Fate of Microplastics, Derived from Disposable Masks, in Natural Aquatic Environments.

This paper mainly reviews the fate of microplastics, released from used face masks, in the water environment. Through previous experiments, the amount of fiber microplastics released from used face masks into aqueous environments was not negligible, with the maximum microplastics releasing amount reaching 10,000 piece·day-1 for each mask. Microplastic derived from these masks often occurred in the shape of polymeric fibers that resulted from the breakage of the chemical bonds in the plastic fibers by the force of water flow. The potential contact forces between microplastics (originating from face masks) with other pollutants, primarily encompass hydrophobic and electrostatic interactions. This critical review paper briefly illustrates the fate of microplastics derived from disposable face masks, further devising effective strategies to mitigate the environmental impact of plastic particle release from the used personal protective equipment.

Incorporating carbon sequestration toward a water-energy-food-carbon planning with uncertainties.

Water-energy-food nexus (WEFN) is the core content in the United Nations 2030 Agenda for Sustainable Development. However, the value of soil and crops' carbon sink function has not yet been fully considered in the managment practices of WEFN system. Here, we developed a water-energy-food-carbon nexus (WEFCN) planning framework that incorporates carbon sequestration and multiple mathematical optimization methods into the practical WEFN management for Henan Province, which is one of major grain-producing areas in China. Uncertainties from multiple objectives, scenarios, and different stakeholder interests are captured. We found that wheat has the largest carbon sequestration, followed by corn and oil-bearing crops, while other crops have implicit carbon sequestration. Since chemical fertilizer produces the most carbon emissions, the usage of chemical fertilizer needs to be reasonably controlled. Overall, the proposed framework supports optimal decision-making for regional-scale WEFCN management and further unlocks the hidden value of agricultural carbon mitigation.

Study of the adsorption behavior of tetracycline onto suspended sediments in the Yellow River, China: Insights into the transportation and mechanism.

The increasing usage of household drugs has contributed to the widespread distribution of antibiotic pollutants in the aquatic environment. Although previous studies have proven that sediments could act as an important transport vector of antibiotic pollutants, the crucial impact of suspended sediments (SS) on the migration and fate of antibiotics in water bodies remains unclear. This study systematically investigated the performance and potential mechanism of adsorption of tetracycline (TC) on SS in the Yellow River. The results show that physisorption (pore filling, hydrogen bonding) and chemisorption (π-π interaction, surface complexation, and electrostatic interaction) activities contributed to the adsorption of TC onto SS. The mineral components (SiO2, Fe2O3, and Al2O3) of SS were found to be the main active sites for TC adsorption. The contribution of SiO2, Fe2O3, and Al2O3 to the overall TC adsorption could reach up to 5.6 %, 0.4 %, and 73.3 %, respectively. Interestingly, the DFT results suggesting that SiO2 tends to form intermolecular hydrogen bonds with TC, while Fe-O and Al-O play predominant roles in TC adsorption on SS. The MIKE simulations showed that river temperature, initial pH, and SS concentration would significantly affect the concentration of dissolved TC during SS transport. In addition, the presence of humic acid and more acidic environments favored the adsorption of TC on SS. Conversely, the introduction of inorganic cations inhibited the adsorption of TC on SS. This study provides new insights into the adsorption mechanism and migration of antibiotics in rivers with high SS content.

Synthesis and Peroxide Activation Mechanism of Bimetallic MOF for Water Contaminant Degradation: A Review.

Metal-organic framework (MOF) materials possess a large specific surface area, high porosity, and atomically dispersed metal active sites, which confer excellent catalytic performance as peroxide (peroxodisulfate (PDS), peroxomonosulfate (PMS), and hydrogen peroxide (H2O2)) activation catalysts. However, the limited electron transfer characteristics and chemical stability of traditional monometallic MOFs restrict their catalytic performance and large-scale application in advanced oxidation reactions. Furthermore, the single-metal active site and uniform charge density distribution of monometallic MOFs result in a fixed activation reaction path of peroxide in the Fenton-like reaction process. To address these limitations, bimetallic MOFs have been developed to improve catalytic activity, stability, and reaction controllability in peroxide activation reactions. Compared with monometallic MOFs, bimetallic MOFs enhance the active site of the material, promote internal electron transfer, and even alter the activation path through the synergistic effect of bimetals. In this review, we systematically summarize the preparation methods of bimetallic MOFs and the mechanism of activating different peroxide systems. Moreover, we discuss the reaction factors that affect the process of peroxide activation. This report aims to expand the understanding of bimetallic MOF synthesis and their catalytic mechanisms in advanced oxidation processes.

Application and Comparison of Different Models for Quantifying the Aquatic Community in a Dam-Controlled River.

In order to develop a better model for quantifying aquatic community using environmental factors that are easy to get, we construct quantitative aquatic community models that utilize the different relationships between water environmental impact factors and aquatic biodiversity as follows: a multi-factor linear-based (MLE) model and a black box-based 'Genetic algorithm-BP artificial neural networks' (GA-BP) model. A comparison of the model efficiency and their outputs is conducted by applying the models to real-life cases, referring to the 49 groups of seasonal data observed over seven field sampling campaigns in Shaying River, China, and then performing model to reproduce the seasonal and inter-annual variation of the water ecological characteristics in the Huaidian (HD) site over 10 years. The results show that (1) the MLE and GA-BP models constructed in this paper are effective in quantifying aquatic communities in dam-controlled rivers; and (2) the performance of GA-BP models based on black-box relationships in predicting the aquatic community is better, more stable, and reliable; (3) reproducing the seasonal and inter-annual aquatic biodiversity in the HD site of Shaying River shows that the seasonal variation of species diversity for phytoplankton, zooplankton, and zoobenthos are inconsistent, and the inter-annual levels of diversity are low due to the negative impact of dam control. Our models can be used as a tool for aquatic community prediction and can become a contribution to showing how quantitative models in other dam-controlled rivers to assisting in dam management strategies.

The Potential of Spent Coffee Grounds @ MOFs Composite Catalyst in Efficient Activation of PMS to Remove the Tetracycline Hydrochloride from an Aqueous Solution.

The efficient removal of Tetracycline Hydrochloride (TC) from wastewater, which is a difficult process, has attracted increasing attention. Aiming to synchronously achieve the goal of natural waste utilization and PMS activation, we have combined the MOFs material with waste coffee grounds (CG). The catalytic activity of the CG@ZIF-67 composite in the TC removal process was thoroughly evaluated, demonstrating that the TC removal rate could reach 96.3% within 30 min at CG@ZIF-67 composite dosage of 100 mg/L, PMS concertation of 1.0 mM, unadjusted pH 6.2, and contact temperate of 293.15 K. The 1O2 and ·SO4- in the CG@ZIF-67/PMS/TC system would play the crucial role in the TC degradation process, with 1O2 acting as the primary ROS. The oxygen-containing functional groups and graphite N on the surface of CG@ZIF-67 composite would play a major role in efficiently activating PMS and correspondingly degrading TC. In addition, the CG@ZIF-67/PMS/TC system could withstand a wide pH range (3-11). The application of CG in preparing MOF-based composites will provide a new method of removing emerging pollutants from an aqueous solution.

A Comprehensive Exploration on Occurrence, Distribution and Risk Assessment of Potentially Toxic Elements in the Multi-Media Environment from Zhengzhou, China.

Road dust (RD), roadside soils (RS) and river surface sediments (sediments) are important materials for evaluating contaminant levels in urban areas. This study aims to investigate the contaminant characteristics, pollution levels and ecological risks of RD, RS and sediments of potentially toxic elements (PTEs), including Cr, Ni, Cu, Zn, As, Cd, Hg and Pb, in the central urban area of Zhengzhou. Results reveal that RD shows a higher concentration of PTEs when compared to the other two environments. The spatial distribution characteristics suggest that PTEs in RD, RS and sediments may come from different sources. The geo-accumulation index (Igeo) was used to describe that the RD was moderately to extremely contaminated with Cd and Hg, while both RS and sediments were significantly enriched with Cd and Hg. For RD, RS and sediments, the potential ecological risk (RI) demonstrates a high potential ecological risk from Cd and Hg. Overall, PTEs in Zhengzhou road dust present a moderate risk.

Evaluation of aquatic ecological health of sluice-controlled rivers in Huai River Basin (China) using evaluation index system.

The aquatic ecological health status was focused on the Huai River Basin (HRB) from the aspects of water quantity, water quality, water ecology, river connectivity, and riparian habitat environment. Ten monitoring sections were set up in the middle and upper reaches of HRB, and 5 experiments of each section were conducted in July and December from 2012 to 2014. Thus, relevant data on the species, the density of phytoplankton, zooplankton and benthic animals, the concentration of water physicochemical variables, and riparian habitat quality were obtained. Eleven key impact factors were chosen using frequency statistics, theoretical analysis, and correlation analysis methods, forming the evaluation index system of aquatic ecological health. Then, the indicator weight value was determined by the combined weight method, and the health degree was evaluated by the comprehensive index method. On the whole, the aquatic ecological health degree of the upper sections (D1 ~ D3) of the Shaying River ranges from 0.334 to 0.927, which is generally in a "sub-healthy" state. The aquatic ecological health degree of the main section of the Huai River (D8 ~ D10) ranges from 0.362 to 0.777, which is in the "critical" or "sub-healthy" state. The Huaidian Sluice (D5) and Fuyang Sluice (D6) in the middle and lower reaches of the Shaying River had the worst aquatic ecological health. Its water ecological health range is 0.283-0.523, and most of them are under "sub-pathologic." The research results have important theoretical and practical significance. They can enrich the evaluation theories and methods of river aquatic ecological health, help to grasp the aquatic ecological health status in HRB, and provide basic support for aquatic ecological protection and water pollution control in sluice-controlled rivers.

Water ecological security assessment and spatial autocorrelation analysis of prefectural regions involved in the Yellow River Basin.

To have a more comprehensive understanding of the water ecological security status of the Yellow River Basin, this paper constructs a water ecological security evaluation index system founded on the Pressure-State-Response (PSR) model. The indicators are selected by considering factors such as meteorological conditions, population, economy, water resources, water environment, water ecology, land ecology, ecological service functions, pollution control, and capital investment. Then, the "single index quantification-multiple indices syntheses-poly-criteria integration (SMI-P) method was used to determine the water ecological security index (WESI) of 62 cities in the Yellow River Basin, to classify the safety levels, and combined with the spatial autocorrelation analysis to study the regional characteristics. The results prove that: (a) The overall water ecological security of the Yellow River Basin is relatively poor. Half of the 62 cities have reached the second-level warning level, and most of them are concentrated in the upper and middle reaches of the basin. (b) Wetland area is a long-term key factor in the construction of water ecological safety, and the greening rate of built-up areas has an increasing impact on water ecological safety. (c) The overall water ecological security index shows a slow upward trend, with the annual average growth rate was 0.59%. (d) The water ecological security of 62 cities in the Yellow River Basin shows significant spatial autocorrelation. The findings can offer a practical basis for the water ecological management to promote the high-quality development of the Yellow River Basin.

A comprehensive exploration on distribution, risk assessment, and source quantification of heavy metals in the multi-media environment from Shaying River Basin, China.

Comprehensively understand the distribution of pollutants in the multi-media environment at basin scale is of major importance to the ecological risk assessment and pollution control. In this study, multi-media contamination characteristics of eight heavy metals in the water, soil, and sediment from the Shaying River Basin of China have been analyzed to probe their ecological risks and potential sources. Results revealed that heavy metal concentrations in pore water were higher than those in surface water. While the mean concentrations of most heavy metals increased follow the order of bankside soil (BS)

The potential of green biochar generated from biogas residue as a heterogeneous persulfate activator and its non-radical degradation pathways: Adsorption and degradation of tetracycline.

Advanced oxidation aided by sulfate radicals (SO4-) is an effective option for the treatment of refractory pollutants from aqueous solutions. In this work, a metal-free biochar catalyst was prepared using pyrolyzed biogas residue as the raw material. The biogas residue carbon (BRC) obtained at 800 °C showed excellent catalytic activity and adsorption capacity for the removal of tetracycline (TC) with 97.9% of removal efficiency. Such performance is accounted for by the rich pores and accelerated electron transformability conferred by its defect structure with the crucial role of pyrolysis temperature in regulating catalyst properties. The BRC-800/peroxymonosulfate (PMS) system worked predominantly through non-radical pathways with high stability/recyclability without being interfered by organic/inorganic compounds in an actual water environment. The exceelent removal performance is also supported by the kinetic reaction rate of the BRC-800/PMS system as estimated to be 0.03017 min-1. This work provides a simple and effective path for modifying biogas residue waste for versatile applications.

The Potential for PE Microplastics to Affect the Removal of Carbamazepine Medical Pollutants from Aqueous Environments by Multiwalled Carbon Nanotubes.

Microplastics are ubiquitous in aquatic environments and interact with other kinds of pollutants, which affects the migration, transformation, and fate of those other pollutants. In this study, we employ carbamazepine (CBZ) as the contaminant to study the influence of polyethylene (PE) microplastics on the adsorption of CBZ pollutants by multiwalled carbon nanotubes (MCNTs) in aqueous solution. The adsorption capacity of CBZ by MCNTs in the presence of PE microplastics was obviously lower than that by MCNTs alone. The influencing factors, including the dose of microplastics, pH, and CBZ solution concentration, on the adsorption of CBZ by MCNTs and MCNTs-PE were thoroughly investigated. The adsorption rate of CBZ by MCNTs decreased from 97.4% to 90.6% as the PE microplastics dose increased from 2 g/L to 20 g/L. This decrease occurred because the MCNTs were coated on the surface of the PE microplastics, which further decreased the effective adsorption area of the MCNTs. This research provides a framework for revealing the effect of microplastics on the adsorption of pollutants by carbon materials in aqueous environments.

The potential of microplastics as adsorbents of sodium dodecyl benzene sulfonate and chromium in an aqueous environment.

Considering the omnipresence of microplastics (MPs) in aquatic environments, they are expected to exert significatn impacts as carriers for diverse waterborne pollutants. In this work, the adsorptive behavior of two ionic components (i.e., sodium dodecyl benzene sulfonate (SDBS) and Cr(VI)) has been explored against the two types of MPs as model adsorbents, namely poly (ethylene terephthalate) (PET) and polystyrene (PS). The influence of key variables (e.g., pH, particle size, and dose of the MPs) on their adsorption behavior is evaluated from various respects. The maximum adsorption capacity values of SDBS on PET and PS are estimated to be 4.80 and 4.65 mg⋅g-1, respectively, while those of Cr(VI) ions are significantly lower at 0.080 and 0.072 mg⋅g-1, respectively, The adsorptive equilibrium of SDBS is best described in relation to pH and MP size by a Freundlich isotherm. In contrast, the adsorption behavior of Cr(VI) is best accounted for by a Langmuir isotherm to indicate its adsorption across at least two active surface sites.

Iodine Modifies the Susceptibility of Thyroid to Fluoride Exposure in School-age Children: a Cross-sectional Study in Yellow River Basin, Henan, China.

Excessive fluoride exposure has detrimental effects on the thyroid gland, which may be modified by iodine. However, the role of iodine in it remains unclear. This study aims to evaluate the role of iodine in thyroid abnormalities caused by fluoride exposure in school-age children. A total of 446 children aged 7-12 years were recruited from Tongxu County, Henan province, in 2017 (ZZUIRB 2017-018). We obtained demographic information through questionnaire surveys. The concentrations of urinary fluoride (UF) and urinary iodine (UI) were determined by the ion-selective electrode method and the catalytic spectrophotometric method, respectively. The radiation immunoassay was used to determine the serum concentrations of total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH). The B-mode ultrasound was performed to assess thyroid volumes (Tvols). The associations between fluoride exposure and thyroid-related indicators were tested by linear regression models. We found that Tvols increased by 0.22 (95% CI: 0.14, 0.31) cm3 with each standard deviation increment of UF. Moreover, Tvols in boys were more susceptible to fluoride exposure than those in girls, and the Tvols of children with high urinary iodine are less susceptible to fluoride exposure (P for interaction < 0.05). We also observed that TT3 levels were negatively related to UF concentrations at moderate urinary iodine levels (≤ 300 µg/l). Fluoride exposure can elevate the Tvols of school-age children, especially in boys, and high levels of iodine may alleviate this effect to some extent.

Effects of filtration-induced size change on the subsequent transport and fate of graphene oxide in saturated porous media.

A particle size change occurs ubiquitously during transport of nanoparticles in the subsurface and is likely to influence nanoparticle fate and transport behaviours. The effects of this size change on the subsequent transport of eluted graphene oxide (GO) in saturated media were therefore investigated under various ionic strength (IS) and filtration degree conditions. Aggregation kinetics revealed that size change after filtration only occurred at relatively high IS conditions. As the filtration column length increased from 15 cm to 30 cm, sizes of aggregates in filtrates for large-sized and small-sized GO populations decreased and increased, respectively, and both approached to their steady aggregate sizes. Aggregation, straining, sedimentation, bridging, DLVO interactions, or a combination of these mechanisms were involved in the size change process during filtration. After passing through the 30 cm filtration column, filtered GO, in comparison with original GO, exhibited stronger mobility than expected, suggesting neglecting size change will result in underestimation of the nanoparticle mobility in porous media.

Effect of biochar on Cd and pyrene removal and bacteria communities variations in soils with culturing ryegrass (Lolium perenne L.).

Organic contaminations and heavy metals in soils cause large harm to human and environment, which could be remedied by planting specific plants. The biochars produced by crop straws could provide substantial benefits as a soil amendment. In the present study, biochars based on wheat, corn, soybean, cotton and eggplant straws were produced. The eggplant straws based biochar (ESBC) represented higher Cd and pyrene adsorption capacity than others, which was probably owing to the higher specific surface area and total pore volume, more functional groups and excellent crystallization. And then, ESBC amendment hybrid Ryegrass (Lolium perenne L.) cultivation were investigated to remediate the Cd and pyrene co-contaminated soil. With the leaching amount of 100% (v/w, mL water/g soil) and Cd content of 16.8 mg/kg soil, dosing 3% ESBC (wt%, biochar/soil) could keep 96.2% of the Cd in the 10 cm depth soil layer where the ryegrass root could reach, and it positively help root adsorb contaminations. Compared with the single planting ryegrass, the Cd and pyrene removal efficiencies significantly increased to 22.8% and 76.9% by dosing 3% ESBC, which was mainly related with the increased plant germination of 80% and biomass of 1.29 g after 70 days culture. When the ESBC dosage increased to 5%, more free radicals were injected and the ryegrass germination and biomass decreased to 65% and 0.986 g. Furthermore, when the ESBC was added into the ryegrass culture soil, the proportion of Cd and pyrene degrading bacteria Pseudomonas and Enterobacter significantly increased to 4.46% and 3.85%, which promoted the co-contaminations removal. It is suggested that biochar amendment hybrid ryegrass cultivation would be an effective method to remediate the Cd and pyrene co-contaminated soil.

A novel chitosan-vanadium-titanium-magnetite composite as a superior adsorbent for organic dyes in wastewater.

In this research, a novel chitosan (CS)-vanadium-titanium-magnetite (VTM) composite was designed and synthesized. The interaction between CS-VTM and Congo red (CR) dye conformed to a pseudo-second-order model to support the potent involvement of chemisorption. The effects of adsorbent dosage, reaction temperature, and initial solution pH on adsorption of CR were investigated. Approximately 99.1% of CR (100 mg/L) was adsorbed at a CS-VTM dose of 2.0 g/L or above, while such a reaction was favored at temperatures of 65 °C and pH of 6.0. Thermodynamically, the adsorption of CR proceeded spontaneously (ΔG < 0) above 35 °C. According to scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer, and zeta potential analysis, its adsorption on CS-VTM can be attributed to electrostatic attraction and hydrogen bonds. The prepared CS-VTM exhibited superior adsorption performance on removal of CR as evidenced by significantly large partition coefficient of 108.3 mg g-1 µM-1 (equilibrium adsorption capacity of 62.2 mg/g at CR dose of 100 mg/L). Overall, the CS-VTM proved to be a promising and environmentally friendly adsorbent for the highly efficient and effective removal of organic dyes among the comparable sorbents studied to date.

Fe3O4 nanoparticles loading on cow dung based activated carbon as an efficient catalyst for catalytic microbubble ozonation of biologically pretreated coal gasification wastewater.

Cow dung based activated carbon was successfully modified by Fe3O4 nanoparticles as the novel catalyst (Fe3O4 nanoparticles@CDAC) to improve the microbubble ozonation treating biologically pretreated coal gasification wastewater (BPCGW). When the pH, ozone dosage, ozone bubble diameter and catalyst dosage of the ozonation were 7, 0.4 L/min, 5 µm and 3 g/L, the chemical oxygen demand (COD) removal efficiency reached 74% and the ratio of biochemical oxygen demand in five days/COD (BOD5/COD) increased from 0.04 to 0.52, which were attributed to the electron transfer of Fe2+ and Fe3+ in Fe3O4 and enhanced hydroxyl radicals generation by the reaction of iron ions and ozone. Meanwhile, benzene derivatives, naphthalene and aromatic proteins were significantly removed while multiple chain hydrocarbons and their derivatives composed the main residual organic matters. The catalytic activity was slightly decreased even the catalyst has been reused for five times. Therefore, catalytic microbubble ozonation using Fe3O4 nanoparticles@CDAC represented excellent performance treating BPCGW and it is a promising process for wastewater advanced treatment.

Toxicological Assessment of Ammonia Exposure on Carassius auratus red var. Living in Landscape Waters.

To understand the toxic mechanism of ammonia and identify effective biomarkers on the oxidative stress for the fish Carassius auratus red var., acute and chronic toxicity tests were conducted. The 96-h LC50 of total ammonia nitrogen (TAN) for C. auratus was 135.4 mg L-1, the corresponding unionized ammonia (NH3) concentration was 1.5 mg L-1. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione-peroxidase (GSH-Px) and glutathione (GSH) showed an increase with a subsequent falling, while the malondialdehyde (MDA) increased during the chronic test. The SOD, MDA, and GSH could be effective biomarkers to evaluate the TAN oxidative stress, the maximum acceptable toxicant concentration (MATC) was 11.3 mg L-1 for TAN. To our knowledge, this is the first study to propose biomarkers to evaluate potential environmental risk and establish a risk threshold for TAN in C. auratus.