Water, Air, & Soil Pollution最新文献

The cultivation of wheat cultivar with low metal(loid) accumulation efficiently mitigated the transfer of soil metal(loid) to the food chain, thus contributing to ensuring food security. However, current research has focused on the identification of wheat cultivars with low accumulation of a single-metal(loid). The aim of this study was to screen wheat cultivars exhibiting low co-accumulation of multi-metal(loid) (Cd, Pb, and As) (LCAM) and high yield for cultivation and application. In this study, a field experiment was conducted using 16 wheat cultivars to evaluate their accumulation capacities and identify special cultivars by cluster analysis and weighting method. Results showed that the bioconcentration factor (BCF) across 16 wheat cultivars were 0.17 ± 0.05–0.32 ± 0.02 for Cd, (0.39 ± 0.02) × 10⁻³–(1.22 ± 0.58) × 10⁻³ for Pb, and (1.07 ± 0.14) × 10⁻³–(1.96 ± 0.20) × 10⁻³ for As. Cluster analysis based on BCF values revealed cultivars (J5265, YN15, TS21, WN14, and JM22) with LCAM were preliminary selected. WN14 and JM22 were identified as the most suitable wheat cultivars, through comprehensive screening using the multifactor (LCAM, quality and yield) weighting method, demonstrating LCAM, high yields, and good quality. Cd and Pb accumulation were closely related to the conversion of Cd and Pb in soil, Cd and As accumulation was closely related to fatty acid accumulation and ash composition, respectively. Therefore, this study provided valuable insights for cultivar selection (WN14 and JM22) and technical support for ensuring the quality and safety of wheat grain.

Graphic Abstract

Since 1990s, activated carbon (AC) has been used as the main material to remove unwanted chlorine-associated odor and taste from drinking water. Nowadays, many different biochar materials have been proposed in the literature to substitute AC in several applications. This study is testing the possible utilization of biochars to remove chlorine. Different AC, biomaterials, and biochars were tested for their ability to remove chlorine from water solutions. The results for all materials are comparable after a 24-h contact time (87%). The biochar from grape seeds (Gse) showed higher removal efficiency (55% compared to 66% for AC) during the early contact time (1-h) and faster kinetics. Thus, this material, Gse, was further tested in a column study, and thus, was characterized for its surface properties (through SEM, FTIR, equilibrium pH) and for the removal of tap water toxicity. The material characterization techniques were all in agreement or complimentary to each other suggesting that the chlorine removal mechanism is a combination of sorption and oxidation of the surface. The toxicity test suggested 3 times lower water toxicity after the use of Gse as filter material. Overall, the results are promising for the removal of chlorine residues from water, thus, shedding light on sustainable filtering materials (local and robust).

Graphical Abstract

Microplastics (MPs) are increasingly recognized as ubiquitous contaminants, with freshwater systems acting both as sinks and conduits for their transport to marine environments. Yet, data on their occurrence in African freshwater systems—particularly in Nigeria—remain limited. This study assessed their presence in sediments from the River Benue. Samples were collected in December 2023 and processed using NaCl/NaI density separation and H₂O₂ oxidation, while suspected MPs were characterized using FTIR and SEM–EDS. A total of 70 suspected MPs ranging between 0.5–5 mm were recovered, with the southern bank exhibiting higher abundance (43 items kg⁻¹) than the northern bank (27 items kg⁻¹). Fragments and films were the dominant morphotypes. Surface sediments from the southern bank recorded mean particle and mass concentrations of 2.8 ± 1.9 items kg⁻¹ and 20.3 ± 10.8 mg kg⁻¹ d.w, decreasing to 0.8 ± 1.0 items kg⁻¹ and 3.0 ± 4.3 mg kg⁻¹ d.w in deeper layers. On the northern bank, surface layers contained 1.9 ± 2.6 items kg⁻¹ and 17.1 ± 20.7 mg kg⁻¹ d.w, dropping to 0.3 ± 0.58 items kg⁻¹ and 4.2 ± 9.9 mg kg⁻¹ d.w at depth. Tentatively identified polymers included polystyrene, polyethylene terephthalate, and polyamide. Preliminary risk assessment revealed contamination factor values of 1–19 and pollution load index values of 1–4.36, with a PLI_zone of 2.28, indicating polluted conditions. The findings highlight anthropogenic influence on MP contamination and provide critical data on Nigeria’s freshwater systems, underscoring the need for expanded monitoring and implementation of abatement strategies.

Nanotechnology is an emerging field with potential benefits in the environment, medicine, and industry. Among the various nanomaterials, titanium dioxide (TiO₂) nanoparticles are particularly notable for their photocatalytic activity, as well as their biocompatibility and chemical stability. This research aimed to synthesize TiO₂ nanoparticles using green synthesis methods through the use of Pittosporum tobira leaf extracts, where the phytochemicals from the plant served as natural reducing and stabilizing agents for the synthesis. The synthesis was verified through UV–visible spectroscopy, which showed a peak at 375 nm. FTIR analysis revealed the presence of hydroxyl, aromatic, and Ti–O functional groups, confirming the expected structure. SEM images indicated a nanoparticle size of around 30–40 nm, while EDX confirmed that Ti and O were present as primary elements, indicating successful synthesis. The biological evaluation revealed strong activity, with DPPH inhibition reaching 92.5%, anti-inflammatory activity showing 86.9% inhibition of protein denaturation, and anti-hemolytic activity achieving 91.4% inhibition. In addition, green-synthesized TiO₂ nanoparticles degraded PCBs by 91% within five days at a nanoparticle-to-PCB ratio of 1:1. This study presents the first report of TiO₂ nanoparticles synthesized using P. tobira extract, highlighting the novelty and unique potential of this plant in nanoparticle fabrication. Overall, the findings demonstrate that P. tobira-mediated TiO₂ nanoparticles are sustainable, highly active, and multifunctional nanomaterials with significant promise for both environmental detoxification and biomedical applications.

Graphical Abstract

Although the negative impact of contaminants of emerging concern (CECs) on the aquatic environment is a threat, their occurrence and removal in Brazilian wastewater treatment plants (WWTPs) remain largely unknown. This study monitored 225 CECs from multiple classes in two WWTPs applying different treatments and their efficiency in removing CECs was compared. Both WWTPs promoted a large reduction in CECs concentration, 81% and 97% of the total load for WWTP-A (aerated lagoon + sedimentation lagoon) and WWTP-B (activated sludge + sodium hypochlorite disinfection), respectively, with the latter also promoting 78% total organic carbon removal. The concentration of CECs ranged from 39 to 374,610 ng L⁻¹ in the raw influent and from 2 to 36,416 ng L⁻¹ in the effluent. The Principal Component Analysis score plot shows three agglomeration tendencies based on CECs concentration, with caffeine and metformin appearing isolated due to their high incidence. The hierarchical clustering dendrogram highlights similarities between influents (80%) but clear differences in effluents (50%), indicating distinct treatment efficiencies. Although residual concentrations were detected in the effluent, Environmental Risk Assessment indicated no significant risk to fish, Daphnia magna, or green algae if a dilution factor is considered. These findings highlight the higher efficiency of activated sludge–based systems and provide useful data on the occurrence and efficiency of different treatments toward removal of microcontaminants in urban WWTPs, supporting future monitoring and regulatory initiatives.

Graphical Abstract

The operation of sluices alters river hydrological conditions, thereby influencing the migration and degradation coefficients of pollutants. However, research focusing on the quantitative correlation between sluice operations and pollutant degradation coefficients, particularly in the unique context of the Loess Plateau, remains insufficient. To address this gap, this study investigated the Danhe River, a typical sluice-controlled system on the Loess Plateau, by combining field monitoring (water mass tracking method) with indoor simulation experiments. Key findings reveal that flow velocity is the dominant factor, exhibiting a significant positive correlation with the degradation coefficients of COD, BOD₅, NH₄⁺-N, and TP (p < 0.01). We established linear regression models (K (COD) = − 1.629 + 6.941v, R = 0.778; K (BOD₅) = − 0.981 + 3.934v, R = 0.754; K (NH₄⁺-N) = − 1.753 + 5.894v, R = 0.869; K (TP) = − 3.454 + 15.151v, R = 0.859) to quantitatively predict degradation coefficients based on flow velocity. Furthermore, river morphology significantly modulates this relationship; the straight river reach demonstrated higher degradation efficiencies than the curved reach. Notably, sluice opening enhanced degradation coefficients in the straight reach (e.g., COD increased by 0.94 d⁻¹) but reduced them in the curved reach, likely due to bank erosion and sediment re-suspension. Consequently, constructing sluices in straight reaches is more conducive to improving the river pollutant degradation coefficient. Temperature also significantly influenced degradation, with coefficients for COD, BOD₅, and NH₄⁺-N increasing markedly from 10 °C to 30 °C. Critically, degradation coefficients under natural hydrodynamic conditions were substantially larger than under static conditions, underscoring the crucial role of hydrodynamics. This study provides novel quantitative models and fundamental data for optimizing sluice operations to enhance the self-purification capacity and improve water quality in river networks of the Loess Plateau and similar regions.

This paper presents the effect of hydraulic retention times (HRT) variations while treating the rice mill wastewater (simulated) in the aerobic inverse fluidized bed biofilm reactor (AIFBBR). For the current AIFBBR system, low-density K5 media was used as the bio-support. The aspects related to hydrodynamic parameters (minimum fluidization velocity (U_mf), gas hold up (ε_g), and superficial airflow velocity (U_g)) of the K5 media concerning the AIFBBR system were furnished in the study. The present AIFBBR system resulted in a minimum U_mf of 0.000231 m/s for the bio-support. HRT values of 6 h, 12 h, 18 h, and 24 h were considered for the current study with 30% bed volume. Maximum removal of 92.74% and 94.42% of chemical oxygen demand (COD) and total organic carbon (TOC) was observed for 24 h HRT. A good amount of NH₄⁺-N removal was observed in the study; however, the PO₄³⁻-P was not removed much. The study has also yielded the attached biomass of 16.63–25.79 mg/bioparticle, 508–672 mg/L of suspended biomass, and a sludge volume index value (SVI) of 43.31–156.25 ml/g. Parameters such as NO₃⁻-N and lignin were also monitored throughout the study.

Graphical Abstract

Runoff from agricultural land often contains pesticide residues that can contaminate surface and groundwater, posing risks to ecosystems and human health. Therefore, there is a need to develop low-cost, effective, and environmentally friendly methods to mitigate this contamination directly at its source. This present study evaluates the efficiency of biofilters composed of biochar, vermiculite, and wood chips in removing pesticides from drainage waters in agricultural settings. A field-scale experimental setup was established using three different substrate configurations, including a vegetated mixture of sorbents with alder seedlings. Five commonly used pesticides (glyphosate, diflufenican, flufenacet, pyridate, and tebuconazole) were tested in exposure experiments simulating runoff events. Results showed that biofilters containing the planted mixture achieved the highest removal efficiencies, with glyphosate removal reaching up to 99.98%. Diflufenican and flufenacet were also effectively reduced, with the lowest removal still exceeding 96%. Pyridate was not detected after filtration, but its metabolite pyridafol was present in all setups, with the planted biofilter showing the lowest response. Tebuconazole demonstrated a significant reduction in vegetated substrates, likely due to root uptake and rhizosphere microbial degradation. The study confirms that combining natural sorbents with vegetation enhances pesticide retention through synergistic effects such as increased sorption and biological activity. This approach offers a low-cost, sustainable alternative to conventional water treatment technologies and may serve as a valuable tool for mitigating pesticide pollution in small agricultural watershed meeting goals of SDG 6 on Clean Water and Sanitation.

Graphical Abstract

To ensure the safe cultivation of Brassica parachinensis, the Cd accumulation trait of Cd pollution-safe cultivar (Cd-PSC), SJ19, was evaluated by comparison with the high-Cd-accumulation cultivar, CX4, under hydroponic condition with gradient Cd treatments. Shoot Cd concentrations in SJ19 were higher than those in CX4 shoots under high Cd concentration (3.0 mg/L), contrary to its low-Cd-accumulation observed under low Cd treatments (0.5 and 1.0 mg/L). Meanwhile, no differences in root and xylem sap Cd concentrations were observed between SJ19 and CX4 under 3.0 mg/L treatment, which allowed higher Cd transportation capacity in SJ19 under high Cd conditions. Additionally, an elevation in phytochelatins (PCs) concentrations was observed in both cultivars as the duration of exposure to 3.0 mg/L Cd increased. PCs profiles varied in shoots and roots, with low-molecular-weight PC₂ being predominant in shoots and high-molecular-weight PC₄ dominating in roots. Simultaneously, PCs related to Cd detoxification and root-to-shoot transportation were higher in SJ19 roots than those in CX4 roots. Furthermore, the PC₄ concentration was linearly correlated with Cd concentration in roots of both cultivars and was higher in SJ19 than that in CX4 under high Cd treatment, thus confirming that PC₄ was the key PCs for cultivar-dependent Cd accumulation trait of B. parachinensis. Our results revealed that PCs biosynthesis was the dominant strategy to cope with Cd stress in B. parachinensis, and Cd accumulation trait of Cd-PSC was reversed via high Cd induction and PCs mediation.

Graphical Abstract

The development of industry has promoted the economic growth, but the centralized development of industrial agglomeration has caused certain problems to the environment. In this study, a typical coastal economic development zone in eastern China is taken as the research area, and bimonthly water sampling was conducted at 48 locations within the Xichao River Basin from January to August 2022, with supplemental sediment samples collected at 9 monitoring sites in July 2022. The aquatic environment and ecosystem of the study area were investigated using an integrated approach combining field sampling, numerical modeling, and high-throughput sequencing techniques. The results show that the water quality in the park exceeds the standard seriously in the case of insufficient sewage treatment capacity, the exceedance rates of COD_Cr, BOD, petroleum pollutant, TN and As are all over 70% and the pollution degree tends to be heavier the closer to the estuary. The Canonical Correlation Analysis (CCA) method indicates that the first two axes together account for 59.76% of the community variation. Fluoride, a major pollutants from the photovoltaic industry, was identified as the key environmental factor driving microbial community changes. Ecosystem stability decreased with increasing pollution levels. Simulations using a one-dimensional water quality model confirmed that both proposed wastewater treatment plants (60,000 and 120,000 t/d capacity) would meet effluent standards. This study provides foundational research methodologies for water environmental management coastal economic development zones and offers practical insights for coastal ecosystem conservation and restoration.