Water, Air, & Soil Pollution最新文献

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.

In recent years, due to the rapid development of industrialisation, plasticisers can be commonly detected in the aqueous environment, and diethyl phthalate (DEP), as an o-phenyl plasticiser, is an emerging pollutant in the aqueous environment, which endangers human health and damages the environment. In this study, a double grounded dielectric barrier discharge (DBD) plasma was utilised for the degradation of DEP wastewater, and a packed-bed reactor was designed so that the degradation rate of DEP was enhanced by the enhanced discharge effect. This paper compares the investigation of the packing performance of different packing materials in the DBD plasma discharge space, optimising a conventional DBD plasma, and testing the filling of different filling materials (glass spheres and glass tubes) in a DBD reactor. Response surface method was used to determine the effect of different materials between size, packing volume and through air flow rate and optimisation experiments were carried out. When glass spheres are used as filler material, the removal rate of the response output optimum can reach 96.62%; When the glass tube is used as filler material, the response output optimum value of 89.78% removal can be achieved. The degradation of DEP by various active particles within the filled-bed DBD discharge system was investigated by free radical inhibition experiments. The removal rates were 17.81%, 48.30% and 17.81% after 40 min of discharge treatment with 5 mmoL/L IPA, BQ and PS, respectively.

One of the produced water treatment methods is adsorption, however, the use of commercial activated carbon as an adsorbent, in industrial scale, makes the process expensive. An alternative for replacing commercial activated carbon is the use of bioadsorbents, which have been gaining emphasis in recent decades, high performance, and low production costs. The objective of this work is to develop an efficient and low cost bioadsorbent by reusing the charcoal from the cashew nutshell (Anarcadium accidentale L.) for the removal of metal ions (Cu²⁺, Pb²⁺ and Cr³⁺), oil and grease content (OGC). The bioadsorbent was pretreated with NaOH and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), point of zero charge (pHpzc) and Boehm titration. The adsorption tests involved adsorption kinetics and equilibrium experiments in a batch system using metallic solution and in a fixed bed column using multi-element metallic and semi-synthetic OGC solution. The characterization results revealed the presence of hydroxyl, carboxyl and carbonyl groups, as well as an irregular and heterogeneous structure, which are favorable characteristics for the adsorption process. The bioadsorbent was able to remove 98.9; 90.9, 77.1 and 100% for Cu²⁺, Pb²⁺, Cr³⁺ and OGC, respectively, in a fixed bed adsorption column. It is concluded that bioadsorbent developed has high potential for removing metals and OGC, in addition to being an abundant product in nature, renewable, biodegradable and its reuse contributes to reduce environmental pollution, waste production and improves the local circular economy through the recovery of the by-product.

In this study, microplastics (MPs) contaminations in Kodek Bay, North Lombok, West Nusa Tenggara, Indonesia, were investigated from water, sediment, and marine animal samples to evaluate the impact of waste discharges from anthropogenic activities and river run-off around the bay. The samples were collected from three site categories: port, residential area, and aquaculture floating net cages. Water quality in each site was also observed. Three marine animals with different feeding regimes were selected to assess MPs contamination, including pompano (Trachinotus blochii), crab (Ocypode kuhlii), and oyster (Crassostrea sp.). A series of extraction protocols followed by stereomicroscope observation were conducted to identify the MPs' abundance, form type, and color. Next, the MPs polymer type was characterized using Fourier Transform Infra Red (FT-IR) at a frequency range 4000–400 cm-1 resolution 4.0 with Bruker Alpha II spectrometer. The results showed no significant difference (P < 0.5) in MPs abundance in water (15.75–20 part.L⁻¹) and sediment (10.25–12.3 part.kgDW⁻¹) samples between the sites as well as between marine animals (23.20–27.03 part.ind⁻¹). Various MPs types and color proportions were observed from water and sediment from different sampling locations and marine animal body parts. The MPs form types found include fragment (6–58%), film (7–49%), fiber (2–25%), and pellet (20–78%), while based on the MPs particle colors, the proportion were black (14–78%), yellow (7–33%), blue (2–25%), red (8–30%) and green (2–30%). Analysis of functional groups and polymers from water, sediments, and marine animal samples indicated the presence of PS (Polystyrene) and PE (Polyethylene). The study results indicated widespread MP contamination in the Kodek Bay area. The results serve as a scientific-based recommendation for policymaking to further prevent MPs contamination in the area.

Aquaculture wastewater (AW) is contaminated with nitrate (NO₃⁻) and nitrite (NO₂⁻), which can cause eutrophication if discharged without treatment. This study explores using coffee grounds biosorbent (CGB) to recover NO₃⁻ and NO₂⁻ ions from AW and reutilize the spent sorbent as a soil conditioner. The process study, adsorption isotherms and kinetics of the adsorption of NO₃⁻ and NO₂⁻ were deduced using several parameters and models. Spent sorbents were also compared with the commercial potting soil based on Okra plant growth metrics. The highest recovery efficiency for NO₃⁻ and NO₂⁻ was 98.6% and 95.0%, respectively, using 5 g/L of CGB with a 2-h contact time at pH 11. Adsorption followed the Freundlich isotherm and pseudo-first-order model, indicating multilayer adsorption on a heterogeneous surface. Optimal Okra growth was observed with 10% spent CGB (SCGB). This study highlights the potential of waste biosorbents for nutrient recovery and subsequent use as soil conditioners.

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This study aims to assess groundwater quality and the human health risks associated with nitrate contamination using a human health risk assessment model. 45 groundwater samples were collected in 2016 and 2023 in the Angads aquifer. According to the findings, the groundwater was brackish (TDS > 1000 mg/L), extremely hard (TH > 450 mg/L CaCO₃), and contained ions in the sequence Na⁺  > Ca²⁺  > Mg²⁺  > K⁺  > NH₄⁺ for cations, and Cl⁻ > HCO₃⁻ > SO₄²⁻ > NO₃⁻ for anions. The TH-TDS graph and the groundwater quality index (GWQI) show that the majority of samples are unfit for consumption. Based on NO₃⁻ concentrations most often observed in the south of the research area, where many activities are likely to be sources of nitrates, the human health risk assessment reveals high non-carcinogenic risks for people living in the region, particularly for infants (71.1% on 2016 and 93.3% on 2023). Consumption of groundwater contaminated with nitrates over a long period could present a potential risk to human health.

Sunflower bottom ash (SBA), rich in potassium (K) and low in heavy metals, making it a potential solution for cadmium (Cd)-polluted acidic farmland. Field experiments were conducted to investigate the effects of adding different concentrations of SBA (0%, 0.1%, 0.3%, 0.5%, 1.0%) to Cd-contaminated acidic soil on heavy metal bioavailability, soil fertility, and bacterial community structure. The results showed that the bioavailability of Cd decreased from 0.29 mg/kg in the CK treatment to 0.08 mg/kg in the 1% treatment, and the pH increased from 5.7 to 8.1. Notably, in the 0.3% treatment, catalase, urease, and alkaline phosphatase activities reaching 20, 560, and 4.3 (a.u), respectively, and 16S rRNA sequencing analysis revealed that the Shannon index of the 0.3% treatment was the highest at 5.364, indicating the most favorable soil environment with the greatest microbial diversity. Terrabacter was significantly positively correlated with heavy metal availability, while Dyella exhibited significant positive correlations with the availability of phosphorus (P), K, and soil pH, and Terrabacter and Dyella in the acidic Cd-contaminated soil contributed to reducing heavy metal toxicity and enhancing soil fertility. This study offers a promising approach for resource utilization of SBA, and provides a new technology for improving Cd-polluted acidic farmland.

Soluble electron shuttles have been found to facilitate the biodecolorization of azo dyes, yet their loss due to water flow can escalate costs and risk secondary pollution. This issue can be mitigated by immobilizing the shuttles. In this study, we immobilized phenazine-1-carboxylic acid (PCA) using a chitosan/polyvinyl alcohol gel carrier and investigated its effect on the degradation of disperse red S-R (DR S-R) by Shewanella oneidensis FJAT-2478. Both free and immobilized PCA significantly increased the decolorization rate within a 50–400 mg/L concentration range for DR S-R, without affecting the final efficiency. Immobilized PCA was slightly less effective than free PCA (4.18-fold at 100 mg/L DR S-R), but was 3.63-fold more effective than the control group without PCA. It also demonstrated excellent reusability, retaining 83% of its initial activity after 10 cycles. Unlike free PCA, which reduced flavin secretion of FJAT-2478 by 36.4%, immobilized PCA increased it by 19.5%, indicating potential differences in their electron transfer modes. This study highlights the potential of immobilized phenazine-based electron shuttles in biologically decolorizing disperse dye wastewater.

Graphical Abstract

This paper is focused on an overview of developments and validation procedures in analytical methods for the detection and quantification of emerging contaminants from multiple groups of environmental contaminants in the environment: polyaromatic hydrocarbons (PAHs), phthalate esters (PEs), alkylphenol ethoxylates (APEOs), alkylphenols (APs), and butylated hydroxytoluene (BHT) in river sediments. Especially, the simultaneous extraction of several analyte groups from sediment samples is currently uncommon, but from the perspective of green analytical chemistry, it is highly desirable. In simultaneous analysis, multiple groups of substances are determined at once instead of through several individual analyses, saving energy, time, and chemicals while significantly increasing laboratory throughput. This review reports different approaches for monitoring the presence of environmental contaminants from four different groups of contaminants from river sediments. There are plenty of sampling techniques, with the core and grab sampling being the most employed at present. Sample preparation is a challenging part of the whole analytical method, providing ample opportunity for optimization in accordance with green analytical chemistry principles. Various extraction schemes, including ultrasound-assisted extraction techniques, accelerated solvent extraction, and microwave-assisted extraction are energy-intensive techniques but may be considered "green" due to their possibility to reduce the consumption of organic solvents, which are usually considered toxic. Quick, Easy, Cheap, Effective, Rugged and Safe extraction (QuEChERS) in the case of satisfactory validation parameters is well-evaluated and utilized. The most recent developments in extraction and clean-up techniques for simultaneous analysis of two, three or four groups of contaminants are showing promising results. Separation and detection techniques are shortly discussed. Further optimizations of analytical methodologies are needed, and future developments in the field of analytical methods for sediment samples are expected for more efficient and faster acquisition of data on the presence of contaminants in real monitoring samples.

Predicting air quality is essential for environmental monitoring and public health. In this work, we suggest a novel method for time series forecasting that uses Long Short-Term Memory (LSTM) networks and the Model-Agnostic Meta-Learning (MAML) algorithm to explicitly target air quality factors. The dataset employed includes features such as carbon monoxide concentration, sensor responses, and meteorological variables. Through extensive experimentation, our MAML-enhanced LSTM model demonstrates improved adaptability to new air quality forecasting tasks, particularly when data is limited. We present comprehensive results, including comparisons with traditional LSTM models, highlighting the efficacy of the proposed approach. This research contributes to the advancement of meta-learning techniques in the domain of environmental monitoring and offers insights into the potential of MAML for enhancing time series forecasting models.