环境•农林最新文献

The pollution effects of microplastics (MPs) on the feeding of the heterotrophic dinoflagellate species, Noctiluca scintillans, was investigated. The algal prey species, Dunaliella tertiolecta, was fed to N. scintillans and fluorescent microspheres were used as surrogates for microplastic wastes. Holling's type II functional response model revealed that N. scintillans could reach a maximum prey ingestion rate of 2,242 cells grazer⁻¹ d⁻¹ (~ 214 ngC grazer⁻¹ d⁻¹) under normal conditions. In exposure to a mixture of prey and MPs, N. scintillans showed mean prey ingestion rates of 1,078 and 820 cells grazer⁻¹ d⁻¹ at Prey:MP ratios of 500:1 (i.e., ~ 88 MP particles mL⁻¹) and 5000:1 (i.e., ~ 8 MP particles mL⁻¹), respectively. The number of N. scintillans cells with ingested MP particles increased with decreasing Prey:MP ratios (200:1, 50:1, 10:1, and 1:1), indicating the non-selective feeding between the algal prey and MP particles. This study is the first one to investigate the effects of microplastic pollution on this common red-tide-causing dinoflagellate species. We urge that more research is needed to reveal the ecological implications of microplastic pollution in the marine ecosystems.

Urban land cover changes impose multiple sources of contamination that severely degrade groundwater quality. The present study evaluates the seasonal assessment of groundwater quality in the unplanned urbanized city of Vellore, Tamil Nadu, India using hydrogeochemical analysis, multivariate statistical analysis and LULC map using GIS techniques. A total number of 96 groundwater samples were collected and analyzed in the year 2022. The Piper diagram shows that groundwater is dominated by Mixed Ca-Na-HCO₃, Mixed Ca–Mg–Cl and Na-Cl-SO₄, water types. Exceedances of BIS limits were observed for parameters such as Ca, Mg, K, Cl, NO₃, F and Coliforms during all the seasons in most of the samples. Principal component analysis (PCA) divides the water quality parameters into strong and moderate loading. Q mode of Hierarchical Cluster Analysis (HCA) reveals three clusters: residential, commercial and mixed zones, whereas R modes exhibited dominant parameters such as NO₃, Cl, TDS, Mg, F and Na. Both, high loading in PCA and the samples of Q mode and R mode exceeding the BIS-2012, limits clearly indicates that, the groundwater of this region is highly affected by the indicators of significant urban and geogenic influence. Further, the overlay analysis of Land Use and Land Cover map and groundwater samples, shows clear evident that the indicators present in the groundwater is corresponding to the urban activities of the study area. Therefore, this comprehensive study in Vellore, Tamil Nadu, will shed light on the sources of contaminants affecting groundwater quality and how they change with the seasons through the use of an integrated approach.

The effects of application of olive mill wastewaters (OMW) has been mainly studied in the short-term, while the literature about its impacts after many years has been much lower. This study has monitored some soil physico-chemical parameters after 20 years from OMW application. Two OMW application strategies were tested: intermittent irrigation (i.e., every two years) and continuous irrigation (i.e., each year), both at a dose of 50 m³/ha per year; a non-irrigated soil was assumed as control, since never treated with OMW. Comparisons between long-term and short-term changes (from a previous investigation) were also carried out for key soil properties. In comparison to the control sites, all physico-chemical properties of soils treated with OMW significantly changed, regardless of the irrigation strategy. Noticeable increases were measured for soil salinity (up to + 70%) and content in polyphenols (+ 120%), which suggests paying attention to avoid degradation in soil quality. These effects were lower in the case of intermittent irrigation. The study also evidenced that some short-term undesired effects of OMW application decreased several after irrigation (e.g., increase in soil pH and salinity) down to tolerable values. Therefore, it can be concluded that the annual or inter-annual applications of OMW make the soil fertility stable or even increase it in the short term, but intermittent irrigation is advisable to avoid undesired impacts for crops and ecosystem.

Constructed wetlands are becoming increasingly popular around the world to remove nutrients, organics, trace elements, pathogens, and other contaminants from wastewater and/or runoff water. Generally constructed wetlands can be built considering several designs connected to the flow which can be either saturated or unsaturated, vertical or horizontal, surface or subsurface and all the possible combinations. The CW2D (Constructed Wetlands 2D) multi-component reactive transport module was developed as an extension of the Hydrus-2D. CW2D was created to simulate biochemical transformation and degradation processes for organic matter, nitrogen and phosphorus in constructed wetlands with subsurface flow. The IWA Activated Sludge Models, which use monod-type expressions to describe the process rates, serve as the foundation for the mathematical structure of CW2D. All process rates and diffusion coefficients are temperature dependent. The biochemical components included in CW2D are dissolved oxygen, three fractions of organic matter (readily- and slowly-biodegradable, and inert), four nitrogen compounds (ammonium, nitrite, nitrate, and dinitrogen), inorganic phosphorus, and autotrophic and heterotrophic micro-organisms. Considering the background knowledge, the review provides recent applications of CW2D module with HYDRUS for simulation of wastewater treatment performance of constructed wetlands and suggests the possibility of addition of more features in CW2D module for more realistic simulation outcomes.

Reverse osmosis is a critical step in the pursuit of zero discharge for coal gasification wastewater treatment; however, the high-salt concentrates generated in this process contain refractory organic compounds, such as indole, quinoline, and pyridine, which pose significant challenges for salt recovery. In this study, catalytic ozonation using a novel Cu-Co-Mn/activated carbon catalyst was introduced to efficiently degrade these persistent organic pollutants. The optimized conditions were a pH of 9.0, a catalyst dosage of 1.3 g/L, and an ozone dosage of 1.0 g/L. Our findings reveal that the catalytic effect promotes the accumulation of hydroxyl-free radicals, which provide the necessary energy for effective degradation. The removal efficiencies of indole, quinoline, and pyridine by catalytic ozonation were remarkably high at 92.31%, 90.56%, and 80.63%, respectively. Pyridine, identified as the most resistant compound, had its electronic structure calculated using density functional theory (DFT) with Gaussian 09 software, offering new insights into the underlying degradation processes. The results demonstrate that the novel catalyst significantly boosts ozonation efficiency, offering a promising approach for treating high-salt coal gasification wastewater.

The effects of magnetic biochar (SMBC) prepared from Siraitia grosvenorii residues on the mobility, speciation and bioavailability of Pb and Zn in the soil were studied. SMBC was characterized by N₂ adsorption–desorption isotherm, Scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction. Three different extractions of Pb and Zn by TCLP, CaCl₂ and PBET were used to simulate mobility, availability and bioaccessibility, respectively. SMBC was incubated with contaminated soils at rates of 0, 1, 2.5, and 5.0% by weight for 5 days and 30 days. SMBC was effective for both Zn and Pb immobilization, and the immobilization effect increased with the increase of SMBC dosage. It was observed that there was a slight rebound of TCLP-extractable Pb and CaCl₂-extractable Pb in the SMBC-treated soils after 30 days of incubation. The chemical fractions of Pb and Zn from sequential extractions were used for evaluating mobility and availability. After 30 days of incubation, the chemical species of Pb in the control distributed in the decreasing order of OX (26.5%) > CB (20.99%) > OM (18.52%) > RS (18.02%) > EX (15.95%) and RS (27.35%) > OX (24.88%) > EX (19.95%) > OM (17.42%) > CB (10.38%) for Zn in the soil. Siraitia grosvenorii residues has a broad application prospect in the remediation of heavy metal polluted soil in the future.