环境•农林最新文献

Triclosan (TCS) is widely used in personal care products due to its effective antibacterial properties. However, the increasing frequency of TCS detection in global surface waters, particularly following the heightened use of disinfectants during the COVID- 19 pandemic, underscored the need for careful environmental risk assessment. In this study, we conducted ecological toxicity assays using the model organism Caenorhabditis elegans to investigate the potential risks of environmentally relevant concentrations of TCS. After 72 h of exposure, specific reproductive toxicity, including a decrease in eggs in utero at concentrations ranging from 0.1 to 5 μg L⁻¹ was observed. The predicted no-effect concentration (PNEC) was determined based on a 10% inhibition of egg formation using the Hill and Weibull models. At lower concentrations, TCS inhibited total brood size in C. elegans and increased intracellular ROS levels and sod- 3 antioxidant gene expression. The reproductive risk of TCS in urban freshwater environments was further assessed using predicted environmental concentrations (PEC) from 2019 to 2022 and the PNEC simulated in this study. Risk quotient (RQ) and exceedance risk (ER) analyses indicated a high reproductive risk of TCS (RQ > 1 or inhibition > 10% at ER = 0.5) in urban rivers and lakes, particularly in the post-pandemic period. Given the global concern over the potential hazards of TCS, our findings contributed to understanding its environmental risks in urban freshwater systems and provided a basis for regulatory authorities to develop appropriate control measures and management strategies.

Spring water is one the important source of fresh water in the Himalayan region which is used for drinking, irrigation, and industrial purposes. With the unprecedential rise in the urbanization and industrialization, has posed severe threats to spring water resources. The water quality of springs has severely deteriorated owing to the changes in land use patterns. In the present study, the physiochemical parameters of the spring water of intermountain Doon valley, present at the eastern Himalayan region were assessed in order to simultaneously understand the hydrogeochemistry of the region and the factors controlling the ion chemistry of water. In total nine water samples were collected from three different water springs during three different seasons and were different water quality parameters were analyzed viz. temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), bicarbonate (HCO₃⁻), sulphate (SO₄²⁻), chloride (Cl⁻), nitrate (NO₃⁻), and fluoride (F⁻) total hardness (TH), calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺) and potassium (K⁺). The heavy metal analysis (for Cu, Pb, Ni, Cr and Cd) for all the three seasons was found to be below the BIS threshold for drinking water quality. The total coliform and E. coli tests were conducted and was found to above the BIS standard's permissible limits. The Water Quality Index (WQI) was evaluated to check the suitability of water for drinking purposes and as per WQI index water and was found to be under the good category for drinking purposes. The spring water have fallen under the excellent to good category for irrigation purposes. The high ratio of Ca²⁺ + Mg²⁺ / Na⁺ + K⁺ and a low ratio of Na⁺ + K⁺ /TZ⁺ indicated the dominance of carbonate weathering in the studied area. The piper trilinear diagram indicated the Ca²⁺-Mg²⁺-HCO₃ and Ca²⁺-Mg²⁺–HCO₃^– -SO₄²⁻ were dominant hydro-chemical facies in the study area.

Graphical Abstract

Revegetation is widely recognized as a promising strategy for the large-scale bauxite residue management and disposal. However, its potential ecotoxicological risks, particularly the ecotoxicity of treated bauxite residue leachate on aquatic organisms, remain largely unknown. This study assessed the effects of exposure to bauxite residue leachates from short-term revegetation on oxidative stress and DNA damage in zebrafish (Danio rerio) tissues. The results revealed significant variations in the activities or levels of superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (AChE), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) in zebrafish liver, brain, gill, and muscle tissues after 7, 14, 21, and 28 days of exposure to bauxite residue leachates. The integrated biomarker response (IBR) index indicated that leachate from treated residue exhibited greater toxicity to the liver, gills, and muscle compared to untreated residue, whereas brain tissue exhibited the opposite trend. Correlation analysis revealed significant positive and negative correlations between pH, EC, Al, Na, As, and V in leachates and oxidative stress/DNA damage biomarkers in zebrafish tissues. Despite the neutral pH (7.44 ± 0.26) and low concentrations of Al (0.67 ± 0.01 mg·L⁻¹), As (4.65 ± 0.20 mg·L⁻¹), and V (0.01 ± 0.00 mg·L⁻¹) in the treated residue leachate, the relatively higher Na concentration (22.33 ± 3.61 mg·L⁻¹) and other contaminants introduced by amendments and bauxite residue likely played a key role in inducing oxidative stress and DNA damage in zebrafish tissues. These findings highlight the importance of carefully selecting amendments for revegetation to support plant establishment while minimizing secondary contamination risks. This study provides valuable insights into the environmental risks of short-term bauxite residue revegetation, contributing to the development of more effective and sustainable revegetation strategies.

This study introduces an efficient and environmentally friendly approach by utilizing synthesized ZnO nanoparticles to degrade pharmaceutical contaminants. The structural and optical properties of the nanoparticles were extensively characterized using Fluorescence spectrometry, UV–VIS spectroscopy, FTIR spectroscopy, particle size analysis, Zeta potential, PXRD, FE-SEM, and EDAX techniques. The photocatalytic degradation of paracetamol (PARA) and diclofenac (DCF) was successfully achieved using ZnO in combination with Fenton’s reagent across a wide pH range (2.5, 7.0, and 10.5) and various light sources. Enhanced degradation efficiency was observed at lower pH levels (pH = 2.5) than at higher pH values (pH = 7.0 and 10.5) under all light sources tested. Notably, ZnO achieved complete degradation within 45 min under UV254 exposure at pH 2.5, outperforming other conditions tested. This research highlights the potential of ZnO photocatalysts and their functionalization to effectively mitigate the environmental impact of pharmaceutical pollutants.

Since municipal solid waste incineration fly ash (MSWI FA) contains a large amount of potentially toxic heavy metals that need to be safely treated before landfill, solidification/stabilization chemical stabilization method is one of the most commonly used methods for MSWI FA treatment. To investigate the effects of different inorganic and organic chelating agents on the solidification of heavy metals (such as Pb, Cd, etc.), immobilization, here we selected three inorganic chelating agents (Na₂S, NaH₂PO₄ and Na₃PO₄) and four organic chelating agents (thiourea, diethyl-mercaptan, DDTC and EDTA Na) for a comprehensive comparison of the heavy metal stabilization and immobilization performance. The leaching and BCR results indicate that under the same low addition conditions, diethyl-mercaptan containing double bond groups exhibits a better chelating effect on most heavy metals (such as Pb, Cd, Cr, Cu and etc.), and the addition of Na₂S can better increase the residual state ratio of Cd. Moreover, we further selected inorganic Na₂S and organic diethyl mercaptan for compounding and it was found that the content of cadmium and lead in the leaching product after the composite chelating agent NS-2 solidified the heavy metals was low, and the lead content was far below the safety threshold of the landfill standard of China (GB16889-2008), which can significantly save the cost of chemicals. This work can provide a reference for the selection and design of effective chelators for stabilizing toxic heavy metals.

Graphical Abstract

Biopesticides are increasingly being used as substitutes for conventional pesticides due to their perceived lower environmental impact. To assess this, the behavior of two biopesticides, limonene and trans-cinnamaldehyde, was evaluated in water samples under sunlight and dark conditions. These compounds are the major components of orange oils and cinnamon extracts, respectively. Their degradation was monitored using gas chromatography (GC) and ultra-high-performance liquid chromatography (UHPLC), respectively, both coupled to a high-resolution quadrupole (Q)-Orbitrap mass spectrometer. The degradation of both compounds followed first-order kinetics with 50% degradation values (DT₅₀) ranging from 0.08 and 2.82 days for limonene, and 1.58 and 13.14 days for trans-cinnamaldehyde. Several transformation products or metabolites of these compounds were identified through untargeted analysis using both suspect and unknown screening modes. Some metabolites for limonene, such as carvone, cymene, limonene-1,2-oxide, p-menth-1-en-9-al or myrtenol were tentatively detected, whereas for trans-cinnamaldehyde, cinnamyl alcohol and cinnamic acid were found. Additionally, the toxicity of the metabolites was predictive using the TEST software, revealing that their toxicity were similar to or slightly higher than the parent compound. This suggests that both the biopesticides and their metabolites pose minimal risk to water matrices, as they exhibit low toxicity and rapid degradation, remaining in the aquatic environment for a short period of time.

Various wastewater and substrates are used as media to preserve existing water reserves for algae cultivation and to eliminate or reduce the cost of chemicals used. In this study, the growth, biochemical content, nutrient removal capacity, and antioxidant activity of Chloroidium ellipsoideum isolated from Lake Sapanca was investigated, using the wastewater as a culture medium taken from the Karaman Wastewater Treatment Facility, located within the borders of Sakarya province. While Bg11 medium was used as a control in the study, the growth of C. ellipsoideum was followed for 7 days in wastewater as diluted and undiluted environments with Bg11 medium. Algae grown in the Bg11:Ww had the highest dry biomass amount, and total protein and total carbohydrate percentages. While the most effective removal of nitrate-nitrogen was observed in the Ww, the most effective removal of orthophosphate was observed in Bg11:Ww. The total phenolic content of C. ellipsoideum grown in three environments was determined as 29.2 mg GAE g⁻¹ in Bg11, 18 mg GAE g⁻¹ in Bg11:Ww and 22.4 mg GAE g⁻¹ in Ww. Additionally, antioxidant activity was determined to be related to the amount of total phenolic substances. As a result, this study has demonstrated its usability in algae production by supporting the wastewater environment with standard nutrient media in attempts to improve the high costs of algae cultivation.

The rapid increase in tropospheric ozone levels, exceeding the phytotoxic threshold (40 ppb), threatens crop yields in India's Indo-Gangetic plains, necessitating the exploration of antiozonants. Biochar application offers a promising, low-risk solution to mitigate the harmful effects of ozone and other abiotic stressors on agriculture. This study investigates the ameliorative effects of biochar amendments (2.5 and 5%) on selected mung bean cultivars (HUM-1 and HUM-6) under elevated ozone (ambient + 20 ppb). Biochar amendments improved foliar characteristics and reduced chlorotic and necrotic spots generated by elevated ozone. Reductions led by ozone in the growth and root-shoot ratio were significantly mitigated in biochar-treated plants. Despite decreased nodulation, the size and biomass of individual nodules increased under biochar treatments. Under ozone stress, the HUM-1 cultivar allocated more photosynthetic assimilates to vegetative parts of the plant, whereas, the HUM-6 cultivar directed greater photosynthates to reproductive structures. Floral and fruit characteristics improved in both cultivars after biochar supplementation, indicating enhanced carbon allocation towards reproductive parts. Biochar treatments also alleviated seed shriveling and size reduction observed under ozone stress, improving seed quality. Biochar amendment was more beneficial in yield protection of sensitive cultivar (HUM-1) than less sensitive cultivar (HUM-6). Findings of the present study suggested that biochar applications of 2.5% and 5% have significant potential to mitigate the adverse impact of ozone on mung bean plants. This study underscores the potential of biochar as a viable agronomic intervention to enhance crop resilience against tropospheric ozone, contributing to food security and sustainable agriculture in the context of climate change.