Water, Air, & Soil Pollution最新文献

This study assessed spatiotemporal water quality, hydrogeochemical characteristics, and heavy metal contamination level of anthropogenically impacted an ancient artificial freshwater wetland, Bhojtal, India, which is crucial for drinking water supply and aquatic biodiversity. The study revealed significant (p < 0.05) seasonal variations in pH, magnesium, and dissolved oxygen levels exceeding permissible limits. Hydrogeochemical classification indicated Cl^‒-Ca²⁺/Mg²⁺ facies dominance post-monsoon. Entropy-based WQI results showed excellent water quality during the monsoon, which declined to good (67% samples) and medium (33% samples) post-monsoon. The trophic state index (TSI) indicated hyper-eutrophication, with values of 81.81 and 82.61. Heavy metals were within safe limits during the monsoon, but high cadmium and lead concentrations were found post-monsoon in the western (Karballa) and southeastern sides (Hallalpur) of the Bhojtal wetland. The study emphasizes the need for land use management to protect water quality, especially post-monsoon. The study signifies the anthropogenic impact on historically significant artificial freshwater wetlands regarding water quality, hydrogeochemistry, and heavy metal pollution, emphasizing the crucial role of effective land use management to sustain these freshwater wetlands for better human health and livelihood.

Water pollution is a growing concern, particularly hexavalent chromium, a toxic pollutant that poses serious environmental and health risks due to its persistence and bioaccumulation. In this study, zeolite A–X was synthesized using an ultrasonic-alkali fusion hydrothermal method, with coal fly ash serving as the source of silica and aluminum, to treat chromium-containing wastewater. The zeolite A–X was successfully synthesized at an alkali-to-ash ratio of 1.5, a hydrothermal temperature of 90 °C, and a hydrothermal time of 12 h. Batch adsorption experiments showed that zeolite A–X achieved optimal adsorption of Cr (VI) at 13.73 mg g⁻¹ under a pH of 3.

Due to the problems of high difficulty and cost of sludge treatment and disposal, the residual sludge with high water content was treated by lysis to realize the reduction. The sludge lysis was conducted by ultravio-sonication (UVS). The effects of wavelength and power of ultraviolet (UV), and sludge concentration and alkali treatment were investigated. The results found that the power of the UV impacted the sludge lysis degree (DD_COD) more strongly than the wavelength, which could increase the amount of TP, PO₄³⁻-P, TN, NH₄⁺-N, protein and polysaccharides in the supernatant but reduce the percentage of carbon, nitrogen and phosphorus. During the lysis by UV-ultrasound, DD_COD increased slightly as the sludge concentration increased, and alkali treatment was more conducive to the dissolution of substances. Under the conditions of ultrasonic power 400 W and frequency 40 kHz, UV power 16 W and wavelength 185 nm, sludge concentration 12,000 mg·L⁻¹, pH = 11 (alkali treatment), the contents of TP, PO₄³⁻-P, TN, NH₄⁺-N were 297.1 mg·L⁻¹, 183.9 mg·L⁻¹, 522.3 mg·L⁻¹, and 58.9 mg·L⁻¹, respectively, with DD_COD reaching up to 63.02%. The improvement of sludge lysis degree was conducive to the release of substances and the reduction the moisture content, which facilitated the subsequent sludge disposal and resource utilization.

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In the study synergic impacts of two amendments included biochar and iron nanoparticles were assessed to monitor the natural polluted soil by gasoil. Contaminated soil samples were collected in a polluted site in southern Iran by gasoil about 3 mg kg⁻¹ of soil. Soil samples were treated with 0, 1, 5 and 10% by weight of biochar and 0, 2 and 10 g kg⁻¹ synthetized iron nanoparticles under the incubation at 28 ± 2 °C and 70% field capacity moisture for 35 days. According to the results, the first order kinetic model fitted well with an R² value of 0.934–0.98 for the soils treated with different levels of biochar and nanoparticles. A significant and positive correlation (r = 0.774, P < 0.01) derived from a polynomial equation was observed between cumulative respiration rate and change percentage of gasoil during biodegradation (ΔTPH). Increasing of biodegradation because of higher biochar is mainly related to improvement of circumstance for higher microbial activity, while inhibition effects of iron nanoparticles on decreasing microbial activities in 10 g kg⁻¹ is related to toxicity of nanoparticles on microbes. After 35 days of incubation, the highest ΔTPH was observed for 10% biochar and 2 g kg⁻¹ iron nanoparticles, as well this treatment showed that the greatest constant of degradation (K = 0.0628) and lowest half-life (t_1/2 = 11.3 days). In overall, the results showed that combined remediation strategies profoundly improve the bioremediation rate by indigenous microorganisms and further studies needs to evaluate different level of iron nanoparticles or even in combined with other remediation technologies. The results highlight the potential of combining biochar and iron nanoparticles for bioremediation, but the observed toxicity of nanoparticles at higher concentrations raises important questions. Further research should focus on understanding the underlying mechanisms of nanoparticle toxicity and their long-term effects on soil ecosystems.

In the context of environmental concerns, microplastic (MPs) pollution emerges as one of the burning issues. The goal of this multifaceted analysis is to provide an up-to-date picture of MPs in the aquatic system with an emphasis on the marine environment. As of now, the growing concern of MP is due to high level fragmentation. The high surface area to volume ratio, crystallinity, and functional groups of MPs allows them to interact with a broad assortment of pollutants, including heavy metals, antibiotics, and persistent organic compounds. Understanding the origin, source, and fate of MPs in the marine environment is challenging, however, crucial for better management and regulation of MPs. Various spectroscopic and microscopic techniques can be applied to analyze MPs. This review article demonstrates the concept of MP lifecycle and footprint covering transport mechanism and pathways, possible characterization, degradation, and remediation processes. Additionally, the ecological and environmental impacts of MPs along with future directions were also highlighted. Thus, fostering global collaboration and innovative research and development can pave the path towards a healthier and cleaner earth for future generations.

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Metal roofs are common in urban areas due to their cost-effectiveness and durability, yet stormwater runoff from building roofs is a major contributor of heavy metals to urban waterways. This study investigated the field performance of a downpipe treatment system (DPTS) using waste seashells to remove aluminium, zinc, and copper from roof runoff. First-flush runoff samples were collected before and after treatment during 30 events over 18 months. Results showed that Zn (85–97%) and Cu (59%) in runoff were predominantly dissolved, while Al (71–90%) was mainly particulate. Metal concentrations were largely influenced by the roof material, and weak correlations were observed with climate characteristics. The DPTS effectively removed particulate metals from copper (76 ± 48% Cu, 80 ± 41% Al) and galvanised (75 ± 49% Zn, 74 ± 27% Al) roof runoff. It also removed dissolved metals from Zincalume® (53 ± 32% Zn, 60 ± 30% Al) and Aluminium (96 ± 5% Zn) roof runoff, sustaining performance over 542 days of operation. Metal removal was linked to initial concentrations, partitioning, and metal affinity for the filter media, with precipitation, where metals formed insoluble compounds, and adsorption, where metals bound to the surface of the shells, as potential mechanisms. This study demonstrates that repurposing waste seashells in roof runoff treatment offers a low-cost, scalable and easily retrofittable solution for treating heavy metal pollution at its source, directly supporting Sustainable Development Goals (SDG), particularly Clean Water and Sanitation (SDG 6), Responsible Consumption and Production (SDG 12), and Sustainable Cities and Communities (SDG 11).

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Wastewater from wheat starch industries is the one with high chemical oxygen demand (COD) level that has adverse effects on the environment and thus special attention to its treatment for the discharge limits satisfaction is crucial. Biological treatment methods have challenges such as requiring extensive space and process time, high sludge production, and efficient management and operation demands. To overcome these challenges, electrochemical methods such as electrocoagulation (EC) and electro-Fenton (EF) can be efficient approaches due to their higher process speeds, minimal facility requirements, and easy operation which make them economically viable. In this study, electrochemical processes, including EC and EF methods were applied for wastewater treatment of a wheat starch industry. After preliminary experiments to identify the effective factors and ranges, the response surface method (RSM) was applied to design the experiments. In RSM seven factors were considered including initial COD, pH, electrode distances, process time, temperature, current intensity, and hydrogen peroxide concentration along with the COD removal efficiency as the response. Statistical analysis showed that hydrogen peroxide concentration and initial COD had the most significant impact, while pH had the least effect on COD removal in the electrochemical process. The optimum results showed that for synthetic wastewater with an initial COD range of 2000–4000 mg/L a COD removal of 75–85% for EC and 89–93% removal for EF were obtained. The results were validated for raw natural wastewater with 88% removal for EC and 92% for EF. In conclusion, while the removal efficiency of the EF process was superior to EC, the former incurs higher costs due to the use of hydrogen peroxide.

Biochar nanoparticles can act as carriers of pollutants in the groundwater, posing a threat to the environment. This study explored the transport and retention behavior of wood-based (NWBCs) and corn-residues-based (NCBCs) acid-modified biochar nanoparticles produced at different pyrolysis temperatures (at 400 °C and 700 °C). The effects of feedstock type, pyrolysis temperature, and input concentration on the mobility of nanoparticles in a saturated sand column were evaluated. Additionally, sequential transport and co-transport experiments were conducted to assess the nanoparticles' ability to remobilize pre-adsorbed Pb²⁺ and the transport of the nanoparticle-Pb²⁺ complex. HYDRUS-1D simulations using depth-dependent and Langmuirian models were applied to evaluate nanoparticles' retention. Nanoparticles produced at the pyrolysis temperature of 400 °C were more mobile than those produced at 700 °C. The highest nanoparticle mobility was observed when acid-modified wood-based biochar nanoparticles produced at 400 °C (NWBC400) were applied at an input concentration of 100 mg L⁻¹, while the lowest mobility was observed at an input concentration of 300 mg L⁻¹. The sequential transport and co-transport experiments revealed that NWBC400 quickly removed the pre-adsorbed Pb²⁺ from the sand. Also, Pb²⁺ in the metal-nanoparticle complex was highly mobile. Moreover, depth-dependent retention was detected as the dominant process describing nanoparticles' retention. As biochar nanoparticles increased the Pb²⁺ mobility in the porous media, adopting policies eliminating such conditions is essential for the environment. Also, understanding and managing biochar nanoparticle mobility can help protect water resources and public health from pollution risks.

Face masks serve as protective measures against pathogens and environmental pollutants. However, microplastic and phthalate pollutants present in the structure of masks may enter the nasal passages, potentially leading to health issues. In this study, we quantified microplastics and phthalate acid esters in masks used by hospital employees in various departments and in the nasal lavage fluid of these personnel before and after mask use. There were 200 participants, and the number of used masks was 160. The results indicated that the highest levels of microplastics (861.21 MP/mask) and Σ phthalate acid esters (3578.99ng/mL) were found in used masks from the laboratory. The amount of microplastics and phthalate acid esters in both masks and nasal lavage samples in the hospital departments were ranked as Laboratory > Physiotherapy > Emergency > Endoscopy. In nasal lavage samples, the amounts of these two pollutants decreased after mask use compared to the no-mask condition. Among the target phthalate acid esters, DEHP was the most prevalent in all mask and nasal lavage samples. These findings can be used for health risk assessment purposes.