Water, Air, & Soil Pollution最新文献

Emamectin benzoate based insecticide and glyphosate based herbicides are widely used in developing countries for agricultural purposes. The problem lies in the total lack of knowledge of data on their uses as well as the absence of scientific data on the potential effects on local biodiversity. This study evaluates the acute and chronic effects of two commercial formulations EMACOT^® and SUNPHOSATE-G^® on juveniles of a prawn species (Macrobrachium macrobrachion) native of large watersheds in Benin. Juveniles with an average weight of 1.49 ± 0.2 g were subjected to six and seven lethal doses of EMACOT^® and SUNPHOSAT-G^® respectively. Thus, swimming behavior, loss of mobility and mortality were monitored every hour for 72 h. Then, sub-lethal effects on molting effectiveness, weight and size gain as well as survival were evaluated on juveniles individually exposed to nominal concentrations of 0.06 and 0.11 mg.L^-1 of EMACOT, and 13.99 and 27.98 mg.L^-1 of SUNPHOSATHE-G. The results showed that the LC₅₀-72 h of the herbicide formulation on juveniles is 279.76 mg.L^-1 which corresponds to 211.78 mg.L^-1 of glyphosate. That of the insecticide is 1.14 mg.L^-1 corresponding to 0.06 mg.L^-1of emamectin benzoate. As for the chronic effects, both concentrations of emamectin benzoate prevented the prawn from molting (1 molt at the start of the experiment against 3 molts for the control subjects in 28 days). As a result, weight gain in these two treatments was very low (0.06 and 0.19 g, respectively) compared to 0.66 g in the controls. For glyphosate, findings with 13.99 mg.L^-1 are similar to those of both doses of emamecin benzoate. On the other hand, no significant effect was observed on the effectiveness of molts within 27.98 mg.L^-1 treatment (3 molts in 28 days). The weight gain was 0.11 g and 0.46 g respectively for both glyphosate sub-lethal doses. The results of this study indicate a significant sensitivity of the prawn juveniles to emamectin benzoate (EMACOT) and a relatively low sensitivity to glyphosate (SUNPHOSATE-G). But the risk is significant when these two pesticides are used in the flood plains of large rivers. In developing countries such as Benin, measures must be taken to review current pesticide use practices in large watersheds.

Desalination is the most promising technology to resolve present water scarcity issues and improvement is required to increase its productivity and various other drawbacks including lower water flux, membrane fouling, and high-energy requirements. Currently available desalination membranes exhibits a water flux of 18–34 L/m².h. Modification of the existing membranes can enhance its performance and thereby makes it efficient for desalination. In this investigation, introduction of Polyvinyl pyrrolidone was aimed to enhance the permeability of the Polysulfone membrane, given that the membrane’s water flux is predominantly influenced by its porosity. Further modification of the membrane was done by adding functionalized multi-walled carbon nanotubes onto the polyamide layer over the polysulfone membrane to improve the salt removal efficiency. The fabricated membranes were characterized by its swelling, porosity, water uptake, surface roughness, contact angle, morphology and surface chemistry. The performance of the fabricated membrane for desalination was evaluated using a cross flow filtration experimental setup. The characterization studies confirmed the modification of hydrophobic polysulphone membrane to hydrophilic by the addition of functionalised multi-walled carbon nanotubes (MWCNTs). The findings demonstrated that the membrane with 0.01% w/v of MWCNTs exhibited enhanced water flux at 42 L/m².h with a salt rejection of 92%. The performance of the used membrane was retained by conducting regeneration study using acid cleaning. This study will be helpful for water managers to come out with a better method to fabricate membranes for desalination.

In the present study, radon concentrations were measured in soil samples collected from different sites in Kadhimiya district center in Baghdad, Iraq. A CR-39 passive nuclear track detectors was used to assess the radon concentrations through the sealed can technique. This study include an assessment of various radiation hazard parameters in 25 soil samples, including the annual effective dose, excess lifetime cancer risk, radium activity, uranium concentration, as well as surface and mass exhalation rates. The mean values were found to be 282.29 ± 3.83 Bq m⁻³ for radon concentration, 7.12 ± 0.096 mSv y⁻¹ for annual effective dose, 24.93 for excess lifetime cancer risk, 0.39 ± 0.002 Bq kg⁻¹ for radium activity, 135.75 ± 1.84 mBq m⁻²h⁻¹ for surface exhalation rate, 3.14 ± 0.04 mBq kg⁻¹h⁻¹ for mass exhalation rate, and 5.91 ± 0.079 PPb for uranium concentration. Consequently, the mean radon concentration exceeded the suggested limits, typically ranging between 200 and 600 Bq m⁻³, and the annual effective dose exceeded the recommended threshold of 1 mSv y⁻¹. However, the radium content was below the recommended limit of 30 Bq kg⁻¹. A significant direct correlation was observed between the radium concentration and both the surface and mass exhalation rates. It is recommended to expand this study to measure radon and thoron gas concentrations within buildings of the study area to enhance the understanding of indoor exposure risks. Additionally, it would be beneficial to estimate the concentrations of other radionuclides, such as ²³²Th and ⁴⁰K, as well as the major cations and anions in the soil to elucidate their potential impact on radon levels. Further actions to control radon exposure in the community to prevent lung cancer is important.

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.