Search Results (61)

Textile wastewater contains recalcitrant dyes and organic matter, requiring efficient, scalable treatment technologies. This study optimized an aluminum-based electrocoagulation (EC) process to maximize color removal (Y₁) and chemical oxygen demand (COD) reduction (Y₂) using synthetic textile wastewater (SWW), and evaluated the practical transferability of the optimized conditions using real textile wastewater (RTW). A rotatable central composite design (CCD) coupled with response surface methodology (RSM) was used to assess the effects of treatment time, NaCl concentration, and applied voltage on both responses. From a modeling perspective, the results reveal the coexistence of symmetric and asymmetric response behaviors; quadratic effects define locally symmetric regions around the optimum, while interaction terms introduce asymmetry due to coupled electrochemical phenomena. Under the optimized conditions (16.5 min, 2.9 g·L⁻¹ NaCl, 18 V), removal efficiencies reached 99% for color and 97% for COD reduction, with a specific energy consumption of 6.6 kWh·m⁻³ and sludge moisture content of 92–94%. To assess applicability beyond bench scale, the optimized voltage, current, and electrolyte concentration were applied to a 50 L batch of RTW collected from the final rinsing stage of a denim dyeing process. Treatment time was extended to 84 min to compensate for the lower current density at the larger scale; under these conditions, 95% color removal and 80% COD reduction were achieved. Full article

This study presents a comprehensive investigation of exact fractional wave solutions and bifurcation analysis for the (3 + 1)-dimensional extended shallow water wave (3D-eSWW) equation with $\beta$-derivative, which models nonlinear wave phenomena in fluid dynamics and coastal engineering. Leveraging the flexibility of the fractional derivative, the model provides a more generalized and adaptable framework for describing shallow water wave propagation. The Modified Extended Direct Algebraic Method (MEDAM) is systematically employed to derive a broad spectrum of novel exact analytical solutions. These include the following: dark solitary waves, singular solitons, singular periodic waves, periodic solutions expressed via trigonometric and Jacobi elliptic functions, polynomial solutions, hyperbolic wave patterns, combined dark–singular structures, combined hyperbolic–linear waves, and exponential-type wave profiles. Each solution family is presented with explicit parameter constraints that ensure both mathematical consistency and physical relevance, thereby offering a robust classification of wave regimes under diverse conditions. A thorough bifurcation analysis is conducted on the reduced dynamical system to examine parametric dependence and stability transitions. Critical bifurcation thresholds are identified, and distinct solution branches are mapped in the parameter space spanned by wave numbers, nonlinear coefficients, external forcing, and the fractional order $\beta$. The analysis reveals how solution dynamics undergo qualitative transitions—such as the emergence of solitary waves from periodic patterns or the appearance of singular structures—driven by the interplay of nonlinearity, dispersion, and fractional-order effects. These insights are crucial for understanding wave stability, predictability, and the onset of extreme events in shallow water contexts. Graphical representations of selected solutions validate the analytical results and illustrate the influence of $\beta$ on wave morphology, propagation, and stability. The simulations demonstrate that varying the fractional order can significantly alter wave profiles, highlighting the role of fractional calculus in capturing complex real-world behaviors. This work demonstrates the efficacy of the MEDAM technique in handling high-dimensional fractional nonlinear PDEs and provides a systematic framework for predicting and classifying wave regimes in real-world shallow water environments. The findings not only enrich the solution inventory of the 3D-eSWW equation but also advance the analytical toolkit for studying complex spatio-temporal dynamics in fractional mathematical physics and fluid mechanics. Ultimately, this research contributes to the development of more accurate models for coastal protection, tsunami forecasting, and marine engineering applications. Full article

Nutrients recovered from municipal and dairy wastewaters in a bioelectrochemical system constructed with terracotta and biochar were used in different soil amendments. These amendments included addition of terracotta (TS), biochar (BS), terracotta and biochar nutrient-rich mixtures from bioelectrochemical systems, DWW (dairy wastewater), and SWW (synthetic wastewater), respectively. Corn growth affected by these amendments was compared with control, termed straight soil (SS). The first experimental setup consisted of 60 plants, four replications per group, and nutrient loadings (0%, 50%, and 100% Hoagland Nutrient Solution, HNS) in the fall season. After harvesting, the plants and soil were analyzed for agro-physical characteristics by various methods. At the 100% nutrient treatment, the TS soil had the best yielding plants. Overall, plants grown in DWW and SWW soil amendments with 0% and 50% nutrient treatments had the best results in plant height, total plant dry weight, the average number of leaves per plant, leaf surface area, shoot dry weight, root/shoot ratio, root surface area, and NBI when compared to the control group. Another test was carried out with 80 corn plants grown using five different soil mediums and using four different nutrient treatments in the spring season. Twenty of the plants were put through a simulated drought to evaluate drought resistance (as measured by plant growth) in different soil amendments. In this test, the SWW soil amendment had a negative effect at 0% HNS and in warm weather. The SWW soil medium had large retention in soil moisture, which had a negative growth effect. It is recommended that the irrigation be monitored closely when applying the SWW soil amendment to avoid overwatering. This research provides critical insights into nutrient reuse in crop production. Full article

At 47° S in Argentine Patagonia, the interaction between the Southern Westerly Winds (SWW) and the Andean barrier generates a steep climatic gradient, providing an ideal setting to evaluate Holocene vegetation responses. This study focuses on the extra-Andean sector, where new pollen records from La Tapera (LTap) and Cisne 7 provide insights into steppe vegetation dynamics under dry conditions. These sequences are contrasted with previously studied records further west (LF, ZB, CMN1, CMN2, and COCU) to assess west–east gradients in vegetation change and moisture availability throughout the Holocene. Western records indicate that the Early Holocene was dominated by grass–dwarf-shrub steppe under arid conditions, followed by increased humidity around 7600 cal yr BP that promoted the development of forest–steppe ecotonal environments. The Middle Holocene was characterised by aridity, reflected in shrub dominance and reduced forest signals, whereas the Late Holocene included a humid pulse between ~1750 and 1000 cal yr BP, followed by renewed aridity over the last millennium. In contrast, eastern records show persistent shrub–dwarf-shrub steppes since ~4700 cal yr BP, with vegetation changes expressed mainly as shifts in the relative dominance of shrubs and dwarf–shrubs rather than floristic replacements. Archaeological sites corroborated and complemented the continuous records, strengthening the reconstruction of environmental variability across different temporal windows. Overall, this west–east comparison highlights the differential sensitivity of ecosystems to SWW fluctuations, reinforcing their role as an important forcing of hydrological balance and vegetation dynamics in mid-latitude Patagonia. Full article

Currently, natural resources are rapidly depleting as a result of increasing construction facilities. Increasing energy consumption with increasing construction is another serious issue. In addition, many problems that threaten the environment and human health arise during the disposal and storage of waste materials obtained in different sectors. The main objective of this study is to investigate the substitution of cotton (CW), chicken feather (CFF) and stone wool waste (SWW) from pumice aggregate in the production of environmentally friendly hollow blocks. To achieve this, CW, CFF and SWW were substituted for pumice at ratios of 2.5–5–7.5–10% in mass, and hollow blocks were produced with this mixture under low pressure and vibrations in a production factory. Various characterization methods, including a size and tolerance analysis, unit volume weight test, thermal conductivity test, durability test, water absorption test and strength tests, were carried out on the samples produced. This study showed that waste fibers of chicken feather and stone wool are suitable for the production of sustainable and environmentally friendly hollow blocks that can reduce the dead load of the building, have sufficient strength, provide energy efficiency due to low thermal conductivity and have a high durability due to a low water absorption value. Full article

In this paper, the production of biomass, pigments, lipids, and carbohydrates and the elimination of ammonium and orthophosphate by the microalgae Chlorella vulgaris, grown in synthetic wastewater (SWW), were studied under different light intensities (3000–10,000 lux), pH (7.5–9.5) and daily illumination time (8–16 h). The best conditions for the autotrophic culture of microalgae were predicted using response surface methodology (RSM). The results showed that the adaptation of the microalgae for this nutrient source was effective. The best conditions for the cultivation of Chlorella vulgaris in SWW were 8.44 pH and a light intensity of 8433 lux in the daily illumination time of 16 h. Under optimal conditions, the production of microalgal biomass, chlorophyll-a, chlorophyll-b, carotenoids, lipids and carbohydrates was 0.534 g/L, 7.46 mg/mL, 3.53 mg/mL, 2.01 mg/mL, 21.40% and 28.46%, respectively. The removal efficiencies of ammonium and orthophosphate from SWW were 97.66% and 58.78% in autotrophic cultures. This investigation introduces a new aspect by verifying the optimized cultivation conditions with real municipal wastewater, indicating that the procedure could be utilized for sustainable production of bioproducts and efficient treatment of municipal wastewater. Full article

Selective water withdrawals (SWWs) are frequently used to minimize the downstream effects of dams by blending water from different depths to achieve a desired temperature regime in the river. In 2010, an SWW was installed on the outlet structure of the primary hydropower reservoir on the Deschutes River (Oregon, USA) to increase spring temperatures by releasing a combination of surface water and bottom waters from a dam that formerly only had a hypolimnetic outlet. The objective of increasing spring river temperatures was to recreate pre-dam river temperatures and optimize conditions for the spawning and rearing of anadromous fish. The operation of the SWW achieved the target temperature regime, but the release of surface water from a hypereutrophic impoundment resulted in a number of unintended consequences. These changes included significant increases in river pH and dissolved oxygen saturation. Inorganic nitrogen releases decreased in spring but increased in summer. The release of surface water from the reservoir increased levels of plankton in the river resulting in changes to the macroinvertebrates such as increases in filter feeders and a greater percentage of taxa tolerant to reduced water quality. No significant increase in anadromous fish was observed. The presence of large irrigation diversions upstream of the reservoir was not accounted for in the temperature analysis that led to the construction of the SWW. This complicating factor would have reduced flow in the river leading to increased river temperatures at the hydropower site during the measurement period used to develop representations of historical temperature. The analysis supports the use of numerical models to assist in forecast changes associated with SWWs, but the results from this project illustrate the need for greater consideration of complex responses of aquatic communities caused by structural modifications to dams. Full article

This study investigated the use of ultrafiltration for sustainable protein recovery and the treatment of shrimp washing wastewater (SWW). Three ultrafiltration membranes with molecular weight cut-offs of 5, 10, and 50 kDa were tested using a combined ultrafiltration–diafiltration process (UF-DF). The performance of each membrane was assessed based on protein recovery efficiency, chemical oxygen demand (COD) reduction, turbidity, fouling behavior, and cleaning efficiency. The 5 kDa membrane showed superior performance, achieving over 90% protein and COD rejection and producing the highest protein-enriched retentate. It also exhibited the lowest fouling index and best cleaning recovery, confirming its suitability for protein concentration and wastewater treatment. This research highlights UF-DF as a promising, eco-efficient technology for valorizing seafood processing effluents by recovering high-value proteins and reducing environmental discharge loads. Full article

Slaughterhouses generate a huge amount of highly polluted wastewater; if left untreated, this effluent could seriously threaten the environment and human health. In the present study, Ag₂O/Ba/TiO₂ nanocomposite was synthesized using the precipitation method, and its efficacy was investigated for the remediation of real slaughterhouse wastewater (SWW) under visible light. Its performance was assessed for the inactivation of bacterial strains identified in SWW and for the degradation of total organic solids, volatile solids, fixed solids, and heavy metals. The results indicated an excellent photocatalytic performance of the synthesized Ag₂O/Ba/TiO₂ nanocomposites, confirmed by 87.3% volatile solids, 30% total organic solids, and 40% fixed solids removal from SWW. The zone of inhibition runs from 4 to 9 mm, and the nanocomposites have demonstrated outstanding bacterial inactivation activity in this range. It has been shown that the synthetic Ag₂O/Ba/TiO₂ nanocomposites can function as an effective photocatalyst for the remediation of SWW and other waste products produced by various industries worldwide. Full article

One of the most pressing environmental problems contemporary civilizations confront is the ever-increasing amount of plastic waste. Because of their impact on every living thing, these wastes are seen as a major issue on a global scale. To counteract the harmful environmental effects caused by conventional disposal methods, it is critical to show that eco-friendly alternatives are viable. Biodegradation is one of the best eco-friendly methods for removing plastic waste. In this study, we aimed to identify bacteria from sewage wastewater treatment plants (SWWs) that could degrade low-density polyethylene (LDPE). Bacterial strains isolated from sewerage wastewater were incubated for 120 days in 50 mL of minimal salt media (MSM) containing 60 mg of low-density polyethylene (LDPE). After four months, our research revealed that Bacillus tropicus (SH4) demonstrated significant potential, degrading the LDPE up to 21.6%. We observed the changes after biodegradation using FTIR, GC-MS, and SEM analysis. In conclusion, microorganisms extracted from sewage wastewater possess the ability to mitigate plastic contamination in aquatic ecosystems. Future proteomics and genome investigations are necessary to elucidate the enzymes and metabolic processes implicated in plastic breakdown. Full article

Urban wastewater (UWW) and landfill leachate (LL) co-treatment using membrane bioreactors (MBRs) is a valuable method for managing LL in cities. Coagulants can enhance the filterability of mixed liquor (ML), but the assessment of fouling is still needed. This research aimed to investigate the effects of co-treating synthetic wastewater (SWW) and real LL on an MBR, as well as the impact of adding poly-aluminum chloride (PACl) and Tanfloc SG. Cell-ultrafiltration experiments were conducted with four different feeds: synthetic wastewater, co-treatment with LL (20% v/v), and co-treatment with the addition of 30 mg L⁻¹ coagulants (either PACl or Tanfloc). Co-treatment aggravated flux loss and reduced the recovery rate; however, Tanfloc and PACl improved recovery after cleaning (by 11% and 9%, respectively). Co-treatment also increased cake and irrecoverable/irremovable inorganic resistances, though coagulants reduced the latter, despite a lower fit of the Hermia models during the first hour of filtration. Co-treatment reduced the removal efficiencies of almost all pollutants analyzed, with the most significant impacts observed on the organic fraction. Coagulants, particularly Tanfloc, enhanced overall performance by improving flux recovery and reducing irreversibility, thus benefiting membrane lifespan. In conclusion, Tanfloc addition yielded the best results in terms of filterability and pollutant removal. Full article

In this paper, soliton solutions, lump solutions, breather solutions, and lump-solitary wave solutions of a (2+1)-dimensional variable-coefficient extended shallow-water wave (vc-eSWW) equation are obtained based on its bilinear form. By calculating the vector field of the potential function, the interaction between lump waves and solitary waves is studied in detail. Lumps can emerge from the solitary wave and are semi-localized in time. The analytical solutions may enrich our understanding of the nature of shallow-water waves. Full article

On 5 September 2022, a Ms 6.8 earthquake struck Luding County, Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China. This seismic event triggered over 16,000 landslides and caused serious casualties and infrastructure damages. The aim of this study is to perform the detailed landslides susceptibility mapping associated with this event based on an updated landslide inventory and logistic regression (LR) modeling. Firstly, we quantitatively assessed the importance of different controlling factors using the Jackknife and single-variable methods for modeling landslide occurrence. Subsequently, four landslide susceptibility assessment models were developed based on the LR model, and we evaluated the accuracy of the landslide susceptibility mappings using Receiver Operating Characteristic (ROC) curves and statistical measures. The results show that ground motion has the greatest influence on landslides in the entire study area, followed by elevation, while distance to rivers and topographic relief have little influence on the distribution of landslides. Compared to the NEE plate, PGA has a greater impact on landslides in the SWW plate. Moreover, the AUC value of the SWW plate significantly decreases for lithological types and aspect, indicating a more pronounced lithological control over landslides in the SWW plate. We attribute this phenomenon primarily to the occurrence of numerous landslides in Permian basalt and tuff in the SWW plate. Otherwise, the susceptibility results based on four models indicate that high-susceptibility areas predicted by different models are distributed along both sides of seismogenic faults and the Dadu Rivers. Landslide data have a significant impact on the model prediction results, and the model prediction accuracy based on the landslide data of the SWW plate is higher. Full article

The global concern about the use of disposable plastics has fed the research on sustainable packaging for food products. Among the virtuous materials, chitosan emerges as a valid alternative to conventional polyethylene films because of its abundance in nature. In this work, a novel film for food wrapping was developed by exploiting shellfish waste according to a vision of circular economy. Compared to previous studies, here, novel ingredients, such as polyvinyl alcohol (PVA), fibroin, and essential oils, were used in a synergistic combination to functionally postpone cheese deterioration. The fermentative procedure applied for the obtainment of chitin contributes to filling the existing gap in the literature, since the majority of studies are based on the chemical pathways that dramatically impact the environment. After pretreatment, the shrimp shell waste (SSW) was fermented through two bacterial strains, namely Lactobacillus plantarum and Bacillus subtilis. A deacetylation step in an alkaline environment transformed chitin into chitosan, yielding 78.88 g/kg SWW. Four different film formulations were prepared, all containing chitosan with other ingredients added in order of decreasing complexity from the A to D groups. The novel films were tested with regard to their physico-mechanical and antioxidant properties, including the tensile strength (12.10–23.25 MPa), the elongation at break (27.91–46.12%), the hardness (52–71 Shore A), the film thickness (308–309 μm), and the radical scavenging activity (16.11–76.56%). The performance as a cling film was tested on two groups of cheese samples: the control (CTR), wrapped in conventional polyethylene (PE) film; treated (TRT), wrapped in the chitofilm formulation deemed best for its mechanical properties. The volatiles entrapped into the headspace were investigated by means of the SPME-GC technique. The results varied across soft, Camembert, and semi-hard cheeses, indicating a growing abundance of volatiles during the conservation of cheese. The bacterial growth trends for mesophilic, enterobacteriaceae, and lactic acid bacteria were expressed as the mean colony forming units (CFU)/mL for each type of cheese at different sampling times (day 2, day 8, and day 22): the highest load was quantified as 8.2 × 10⁶ CFU/mL at day 22 in the CTR Camembert cheese. The TRT samples generally exhibited inhibitory activity comparable to or lower than that observed in the CTR samples. The sensory analysis revealed distinctions in cheese taste between the TRT and CTR groups. Full article

Background and Objectives: Job strain is a psychological, physical, and behavioral stress that occurs at the workplace. Job strain is associated with more than double the normal risk of coronary artery disease (CAD). The main aim of this study was to determine the association between job strain and the following parameters: high-sensitivity C-reactive protein (hs-CRP), the albumin urine excretion rate (AUER), and secondary-level testing. Materials and Methods: This study was a descriptive cross-sectional study conducted on patients who underwent cardiological assessment between October 2023 and February 2024 at the Promedicanon Cardiology Center. This study comprised 210 participants, with two groups: 105 chronic coronary syndromes (CCS) patients and 105 no-CCS patients. The baseline characteristics collected were age, gender, education, rural/urban environment, traditional CAD risk factors, hs-CRP, and AUER. The secondary-level testing included an electrocardiogram (ECG), echocardiography, and enhanced contrast computed tomography (ECCT). Psychological questionnaires comprised the tertiary-level testing, including the PHQ-9 depression questionnaire, and the satisfaction with work scale (SWWS) for job strain (Likert score). Results: The baseline characteristics were all significantly different between the groups (p < 0.05) except for total cholesterol. The hs-CRP level had a mean value of 0.4837 ± 0.19082 in the CCS group; for the no-CCS group, the hs-CRP mean value was 0.2289 ± 0.11009; p-value < 0.001. The AUER had a mean value of 42.770 ± 12.8658 for the CCS group and 26.432 ± 9.7338 for the no-CCS group; p-value < 0.001. For the associations between secondary-level testing and job strain: p < 0.001 for ST depression, negative T-waves, and q-waves; p = 0.415 for atrial fibrillation (AF); p = 0.018 for wall motion studies; p = 0.005 for ECCT. The association between job strain and AF had no statistical significance. The contractility of left ventricle walls and coronary calcification score were associated with job strain, with statistical significance. The p-value was 0.013 for the relationship between depression and the ECCT; for the association between depression and CCS status, the p-value was 0.021. Depression is usually diagnosed in job strain. The association between depression, and coronary calcification, as well as depression and CCS status had statistical significance. Conclusions: Job strain increased the hs-CRP level and AUER in both the CCS and no-CCS patients. The primary and secondary prevention of CHD could also include interventions to reduce job strain. Full article