Search Results (75)

Arsenic contamination in water poses a significant global health risk, necessitating efficient and sustainable remediation strategies. Arsenic contamination affects groundwater in at least 106 countries, potentially exposing over 200 million people to elevated levels, primarily through contaminated drinking water. Among the most affected regions, Bangladesh remains a critical case study, where widespread reliance on shallow tubewells has resulted in one of the largest mass poisonings in history. Bio-based nanomaterials have emerged as promising solutions due to their eco-friendly nature, cost-effectiveness, and high adsorption capabilities. These nanomaterials offer a sustainable approach to arsenic remediation, utilizing materials like biochar, modified biopolymers, and bio-based aerogels, which can effectively adsorb arsenic and other pollutants. The use of environmentally friendly nanostructures provides a potential option for improving the efficiency and sustainability of arsenic remediation from groundwater. This review explores the mechanisms underlying arsenic remediation using such nanomaterials, including adsorption, filtration/membrane technology, photocatalysis, redox reactions, complexation, ion exchange, and coagulation–flocculation. Despite their potential, challenges such as scalability, stability, and regeneration hinder widespread application. We discuss recent advancements in material design, surface modifications, and hybrid systems that enhance performance. Finally, future perspectives are highlighted, including the integration of these bio-derived systems with smart sensing technologies, sustainable water-treatment frameworks, smart design, and life-cycle integration strategies, particularly for use in resource-constrained regions like Bangladesh and other globally impacted areas. Full article

High turbidity in raw water poses a major challenge to drinking water quality and requires effective, sustainable treatment solutions. This work investigates the reduction in turbidity in raw water and the enhancement of overall drinking water quality through the coagulation–flocculation process. The performance of Pine cone extract as a bio-coagulant was evaluated using four different solvent-based extractions (PC-H₂O, PC-HCl, PC-NaCl, and PC-NaOH). The effects of key operational parameters were analyzed, and jar tests were carried out to enhance the coagulation–flocculation process by identifying the optimal conditions. Experimental design was further refined using RSM based on a BBD, incorporating three factors: initial pH, coagulant dosage, and settling time, with turbidity removal efficiency as the response variable. Statistical analysis confirmed that initial pH, coagulant dosage, and settling time significantly influenced turbidity reduction at a confidence level of p-value < 0.05 for all four solvents. Among the extracts tested, PC-HCl demonstrated the highest turbidity removal efficiency. The optimal conditions achieving 78.57% turbidity reduction were a pH of 8.5, a coagulant dosage of 100 mL/L, and a settling time of 120 min. These findings highlight the significant potential of Pine cone extract as an effective, sustainable, and eco-friendly organic coagulant for raw water treatment. Full article

The environmental impacts of industrial processes have increased the demand for sustainable alternatives in wastewater treatment. Conventional chemical coagulants, though widely used, can generate toxic residues and pose environmental and health risks. Biocoagulants, derived from natural and renewable sources, offer a biodegradable and eco-friendly alternative. This review explores their potential to replace synthetic coagulants by analyzing their origins, mechanisms of action, and applications. A total of 15 studies published between 2020 and 2025 were analyzed, all focused on industrial wastewater. These studies demonstrated that biocoagulants can achieve similar, or the superior, removal of turbidity (>67%), solids (>83%), and heavy metals in effluents from food, textile, metallurgical, and paper industries. While raw materials are often inexpensive, processing costs may increase production expenses. However, life cycle assessments suggest long-term advantages due to reduced sludge and environmental impact. A textile industry case study showed a 25% sludge reduction and improved biodegradability using a plant-based biocoagulant compared to aluminum sulfate. Transforming this waste into inputs for wastewater treatment not only reduces negative impacts from disposal but also promotes integrated environmental management aligned with circular economy and cleaner production principles. The review concludes that biocoagulants constitute a viable and sustainable alternative for industrial wastewater treatment. Full article

Natural rubber is a widely used biological polymer material because of its excellent comprehensive performance. Nevertheless, the performance of domestic natural rubber cannot meet the requirements for high-end products such as aviation tires, which has become a constraint on the innovation and upgrading of high-end manufacturing enterprises and the enhancement of global competitiveness in China. To solve the bottleneck problem of natural rubber processing technology, this study systematically analyzed the effects of different varieties of fresh latex ratios on the processing and dynamic properties of bio-coagulated natural rubber. By mixing PR107 and Reyan72059 fresh latex with Reyan73397 fresh latex according to proportion, the fresh latex was coagulated by enzyme-assisted microbials, and the effects of the fresh latex ratio on physical and chemical indexes, molecular weight distribution, vulcanization characteristics, processing properties, cross-link density and physical and mechanical properties of the natural rubber were analyzed. The results showed that the aging resistance of natural rubber coagulated with enzyme-assisted microbial decreased, and the aging resistance of natural rubber increased with the increase in the mixing ratio of PR107 and Reyan72059 fresh latex. The proportion of high molecular weight of the natural rubber coagulated with the enzyme-assisted microbial increased, and the fresh latex mixing had little effect on the molecular weight distribution curve. Under the carbon black formulation, the CRI of the enzyme-assisted microbial coagulated natural rubber compound was relatively larger. Under the same strain conditions, the H-3 compound (PR107:Reyan72059:Reyan73397 = 1:1:3) had the best viscoelasticity and the least internal resistance of rubber molecules. In addition, the cross-link density, tensile strength, elongation at break, and tear strength of H-3 vulcanized rubber were the largest, improved by 23.08%, 5.32%, 12.45% and 3.70% compared with the same H-2 vulcanized rubber. In addition, the heat generation performance was reduced by 11.86%, and the wear resistance improved. Full article

This paper applies a semi-quantitative approach to review the diversity, environmental controls, detection methods, human health risks, and mitigation of cyanotoxins in drinking water systems (DWSs). It discusses the environmental factors controlling the occurrence of cyanotoxins, presents the merits and limitations of emerging methods of their detection (qPCR, liquid chromatography–mass spectrometry, and electrochemical biosensors), and outlines the human exposure pathways and health outcomes with identification of high-risk groups and settings. High-risk groups include (1) communities relying on untreated drinking water from unsafe, polluted water sources and (2) low-income countries where cyanotoxins are not routinely monitored in DWSs. The fate and behavior processes are discussed, including removing cyanotoxins in DWSs based on conventional and advanced treatment processes. The available methods for cyanotoxin removal presented in this paper include (1) polymer-based adsorbents, (2) coagulation/flocculation, (3) advanced oxidation processes, (4) ultra- and nanofiltration, and (5) multi-soil layer systems. Future research should address (1) detection and fate in storage and conveyance facilities and at the point of consumption, (2) degradation pathways and toxicity of by-products or metabolites, (3) interactive health effects of cyanotoxins with legacy and emerging contaminants, (4) removal by low-cost treatment techniques (e.g., solar disinfection, boiling, bio-sand filtration, and chlorination), (5) quantitative health risk profiling of high-risk groups, and (6) epidemiological studies to link the prevalence of human health outcomes (e.g., cancer) to cyanotoxins in DWSs. Full article

The wastewater treatment involves various techniques at different technological levels. Treatment takes place in several stages, of which coagulation and flocculation are the most important. Most suspended solids are indeed eliminated during this stage by the addition of a coagulant. In this research, bio-coagulant was extracted from pumpkin seed (PS) waste after extraction of the essential oils, and used with ferric chloride to treat wastewater from the plant of Chalghoum El Aid-Oued El Athmania Mila. In this study, the Box–Behnken design (BBD) with three factors was used to investigate the effect of pH, organic coagulant dosage Pumpkin seed extract (PSE), and chemical coagulant dosage (FeCl₃) on coagulation–flocculation performance in relation to turbidity, chemical oxygen demand (COD), aromatic organic matter (UV 254), and phosphate. The main characteristics of the raw water were turbidity (250 NTU), COD (640 mg/L), UV 254 (0.893 cm⁻¹), and phosphate (0.115 mg/L). The results obtained were very significant. All the statistical estimators (R² ≥ 97% and p ≤ 0.05) reveal that the models developed are statistically validated for simulating the coagulation–flocculation process. It should be noted that the residual values of turbidity, COD, UV 254, and phosphate after treatment by this process were 0.754 NTU; 190.88 mg/L; 0.0028 cm⁻¹; and 0.0149 mg/L, respectively. In this case, the pH, bio-coagulant dosage, and chemical coagulant dosage values were 4; 17.81 mL/L; and 10 mL/L, respectively. In this study, Fourier-transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) characterization of the bio-coagulant proved the presence of the active functional groups responsible for coagulation, namely carboxyl group. Full article

This study explores the extraction and utilization of tannins from Acacia sp. bark residues for water treatment applications. As a by-product of forest management, Acacia sp. bark is valorized through tannin-based coagulant production, contributing to the circular (bio)economy. A systematic review with bibliometric analysis was first conducted to assess the technical–scientific landscape, identifying methodologies and technologies applied to extract and produce natural tannin-based coagulants from Acacia sp. bark residues for water treatment. From the portfolio of analyzed publications, and which followed the thematic axis addressed and the inclusion criteria, only a single study focuses on performing a life cycle assessment (LCA). Due to the relevance of the topic and the clear lack of existing literature, an environmental assessment of the extraction and production of condensed tannins was performed using the LCA methodology from a gate-to-gate perspective. Among the six process stages, spray drying and adsorption (purification) were the primary sources of environmental impact due to their high energy consumption and makeup ethanol use, respectively. The most effective strategy to enhance environmental performance would be reducing water consumption in extraction, thereby lowering energy demand in spray drying. Since both extraction and spray drying require significant energy, decreasing water use and allowing higher moisture content in the condensed tannin extract would mitigate energy consumption. The LCA study thus proved essential in guiding process development toward a reduced environmental footprint. Full article

Wound and injury healing processes are intricate and multifaceted, involving a sequence of events from coagulation to scar tissue formation. Effective wound management is crucial for achieving favorable clinical outcomes. Understanding the cellular and molecular mechanisms underlying wound healing, inflammation, and regeneration is essential for developing innovative therapeutics. This review explored the interplay of cellular and molecular processes contributing to wound healing, focusing on inflammation, innervation, angiogenesis, and the role of cell surface adhesion molecules. Additionally, it delved into the significance of calcium signaling in skeletal muscle regeneration and its implications for regenerative medicine. Furthermore, the therapeutic targeting of cellular senescence for long-term wound healing was discussed. The integration of cutting-edge technologies, such as quantitative imaging and computational modeling, has revolutionized the current approach of wound healing dynamics. The review also highlighted the role of nanotechnology in tissue engineering and regenerative medicine, particularly in the development of nanomaterials and nano–bio tools for promoting wound regeneration. Moreover, emerging nano–bio interfaces facilitate the efficient transport of biomolecules crucial for regeneration. Overall, this review provided insights into the cellular and molecular mechanisms of wound healing and regeneration, emphasizing the significance of interdisciplinary approaches and innovative technologies in advancing regenerative therapies. Through harnessing the potential of nanoparticles, bio-mimetic matrices, and scaffolds, regenerative medicine offers promising avenues for restoring damaged tissues with unparalleled precision and efficacy. This pursuit marks a significant departure from traditional approaches, offering promising avenues for addressing longstanding challenges in cellular and tissue repair, thereby significantly contributing to the advancement of regenerative medicine. Full article

Poly-γ-glutamic acid (γ-PGA) is a natural polymer whose molecular weight and viscosity are critical for its application in various fields. However, research on super-high-molecular-weight or -viscosity γ-PGA is limited. In this study, the pgdS gene in Bacillus licheniformis WX-02 was knocked out using homologous recombination, and the batch fermentation performances of the recombinant strain WX-ΔpgdS were compared to those of WX-02. Nitrate accumulation was observed in the early fermentation stages of WX-ΔpgdS, and gene transcription analysis and cell morphology observations revealed that nitrite accumulation was caused by oxygen limitation due to cell aggregation. When the aeration and agitation rates were increased to 2.5 vvm and 600 r/min, respectively, and citrate was used as a precursor, nitrite accumulation was alleviated in WX-ΔpgdS fermentation broth, while γ-PGA yield and broth viscosity reached 17.3 g/L and 4988 mPa·s. Scanning electron microscopy (SEM) showed that the γ-PGA produced by WX-ΔpgdS exhibited a three-dimensional porous network structure. At a γ-PGA concentration of 5 mg/L, the fermentation broth of WX-ΔpgdS achieved a flocculation efficiency of 95.7% after 30 min of microalgae settling. These findings demonstrate that pgdS knockout results in super-high-viscosity γ-PGA, positioning it as an eco-friendly and cost-effective biocoagulant for microalgae harvesting. Full article

Reaction Systems (RSs) are a computational framework inspired by biochemical mechanisms. An RS defines a finite set of reactions over a finite set of entities (molecules, proteins, etc). Starting from an initial set of entities (the initial state), a computation is performed by applying all reactions to a state in order to produce the following state, giving rise to a sequence of sets of entities. RSs have shown to be a general computational framework whose application ranges from the modeling of biological phenomena to molecular chemistry and computer science. In this paper, we contribute to research on the application of RSs for modeling biological systems. We consider the problem of modeling hemostasis, for which several models have been defined, starting from the 1960s. Previous models are based on sets of ordinary differential equations, while we develop a discrete model in RSs for pathways of the secondary hemostasis. Then, we implement our model in BioReSolve, a computational framework for RSs that we have previously defined which provides tools for the specification and verification of properties. By using the tools in BioReSolve we derive important observations on the model behaviour for hemostasis, and in particular, we study the role of three important inhibitors, verifying that their presence or absence leads to phenomena such as thrombophilia, or thromboembolism, or excessive coagulation, etc. We can also study computationally the causality relations between the molecules involved in the reactions showing which entities play a fundamental role, thus contributing to the design of more effective and specialized drugs. Our work can hence help to show how to model complex biological systems in RSs and derive computationally and biologically relevant properties of the systems. Full article

Coagulation/Flocculation (C/F) process aims to efficiently eliminate turbidity, TSS, COD, BOD, toxic metals, phosphates, and UV_254nm from wastewater. Both natural and synthetic coagulants, used alone or in conjunction with flocculants, play crucial roles in this treatment. This review summarizes recent trends in coagulants for wastewater treatment, highlighting a wide array of inorganic and organic coagulants that have demonstrated significant efficacy based on reviewed studies. Notably, Crab Shell Bio-Coagulant (CS) excels in turbidity remov5al, achieving a remarkable 98.91% removal rate, while oak leaves protein shows superior performance in TSS and COD removal. Synthetic inorganic coagulants like PALS, PSiFAC_1.5:10:15, and PAPEFAC_1.5-10-15 demonstrate outstanding turbidity removal rates, over 96%. POFC-2 coagulant stands out for efficiently removing TSS and COD from domestic wastewater, achieving up to 93% removal for TSS and 89% for COD. Moreover, the utilization of FeCl₃ as an inorganic coagulant alongside chitosan as an organic flocculant shows promise in reducing turbidity, COD, and polyphenols in wastewater from vegetable oil refineries. PE-2, a novel organic coagulant, demonstrates exceptional efficacy in eliminating turbidity, TSS, COD, and BOD from sugar industry wastewater. Chitosan shows effectiveness in removing TOC and orthophosphates in brewery wastewater. Additionally, CTAB shows high efficiency in removing various toxic metal ions from wastewater. The hybrid coagulants: PAAP_0.1,0.5 and PPAZF accomplish exceptional turbidity removal rates, approximately 98%. Full article

This study evaluated the potential of a biocoagulant produced from prickly pear peel waste valorization and its use as a biocoagulant aid mixed with aluminum sulfate to remove turbidity in domestic wastewater. A central composite design (CCD) and a simplex lattice design (SLD) of two components (biocoagulant and aluminum sulfate) were developed to determine the optimal doses and pH of the biocoagulant and optimal mixing proportions. Both designs optimized the coagulation process from an analysis of variance to fit the experimental data to mathematical models and an optimization analysis to obtain the highest percentage of turbidity removal. The results showed that a water pH of 4 and a biocoagulant dose of 100 mg/L are optimal conditions for a turbidity removal of 76.1%. The potential decreases to 51.7% when the wastewater pH is maintained at 7.8 and a dose of 250 mg/L is used. This efficiency could be increased to 58.2% by using a mixture with optimal proportions of 30% biocoagulant and 70% aluminum sulfate. The experimental data were fitted to two quadratic models, estimating model prediction errors of 0.42% and 2.34%, respectively. Therefore, these results support the valorization of prickly pear peel waste to produce a biocoagulant, which could be used in acid and alkaline wastewater or as a biocoagulant aid mixed with aluminum sulfate. Full article

Platelet-rich fibrin, the coagulated plasma fraction of blood, is commonly used to support natural healing in clinical applications. The rat calvaria defect is a standardized model to study bone regeneration. It remains, however, unclear if the rat calvaria defect is appropriate to investigate the impact of human PRF (Platelet-Rich Fibrin) on bone regeneration. To this end, we soaked Bio-Gide^® collagen membranes in human or rat liquid concentrated PRF before placing them onto 5 mm calvarial defects in Sprague Dawley rats. Three weeks later, histology and micro-computed tomography (μCT) were performed. We observed that the collagen membranes soaked with rat PRF show the characteristic features of new bone and areas of mineralized collagen matrix, indicated by a median mineralized volume of 1.5 mm³ (range: 0.9; 5.3 mm³). Histology revealed new bone growing underneath the membrane and hybrid bone where collagen fibers are embedded in the new bone. Moreover, areas of passive mineralization were observed. The collagen membranes soaked with human PRF, however, were devoid of histological features of new bone formation in the center of the defect; only occasionally, new bone formed at the defect margins. Human PRF (h-PRF) caused a median bone volume of 0.9 mm³ (range: 0.3–3.3 mm³), which was significantly lower than what was observed with rat PRF (r-PRF), with a BV median of 1.2 mm³ (range: 0.3–5.9 mm³). Our findings indicate that the rat calvaria defect model is suitable for assessing the effects of rat PRF on bone formation, but caution is warranted when extrapolating conclusions regarding the efficacy of human PRF. Full article

The consumption of unsafe water in rural areas is a real public health problem in developing countries. This situation mainly affects children under five years of age and causes several deaths and many cases of malnutrition every year. The objective of this study was to evaluate and optimize the capacity of four local plant extracts in the potabilization of unsafe water. Thus, Moringa oleifera and Boscia senegalensis seeds, or Aloe vera and Opuntia ficus-indica mucilages were prepared in a solution and applied during a jar test as biocoagulants and bioflocculants on three raw water samples of 82.3 NTU, 549.8 NTU and 796.9 NTU. After treatment results showed that 0.9 g/L of Moringa biocoagulant or 1 g/L of Boscia biocoagulant applied with 0.4 mL of Aloe vera bioflocculant or 0.6 mL of Opuntia ficus-indica bioflocculant reduced the turbidity of each water sample to values less than 5 NTU after only 15 min of decanting. Moreover, the sanitary quality of the water treated by these different extracts showed a perfect conformity of the physicochemical and microbiological parameters with the standards of acceptability in drinking water decreed by the World Health Organization. Thus, the application of these local plant extracts has made it possible to considerably improve the quality of unsafe water in record time. Their popularization could be an alternative in the fight against malnutrition related to the consumption of unsafe water, especially in rural areas. Full article

Water extracted from natural sources often requires treatment to meet the quality standards necessary for industrial use, involving physico-chemical processes such as coagulation, flocculation, and sedimentation. Inorganic coagulants, such as aluminum sulfate, are commonly used, although they generate a sludge with residual aluminum, classified as hazardous waste. Given this, biocoagulants, such as natural tannin-based polymers, have emerged as a promising alternative. Thus, the objective of this study was to evaluate the environmental performance of water treatment and sludge disposal at an industrial water treatment plant (WTP) of an oil refinery located in Brazil using aluminum sulfate and biocoagulant. The WTP of this study is located in the state of Bahia, Brazil, and is supplied by a surface water body, the Paraguaçu River—Lago de Pedra do Cavalo—which comes from a semi-arid region, and a lake called Catu Korea. The environmental analysis was carried out using the life cycle assessment (LCA) method, using the methodological framework recommended in ISO 14044, followed by economic analysis and circular economy analysis. The inventory used in the analyses contains field data, company records, related literature, and ecoinvent database version 3.3. The impact assessment considered the ILCD 2011 Midpoint+ method package, the AWARE method, and the cumulative energy demand (CED) method in SimaPro 8.4 software. The comparative results showed the greatest impacts in the Energy Demand, Water Footprint, Eutrophication, and Land Use categories for the biocoagulant scenario, in contrast to the Human Toxicity, Acidification, Ecotoxicity, Particulate Matter, Carbon Footprint, and Abiotic Depletion categories for aluminum sulfate. The economic analysis showed that 65% of the operational costs for material and energy inputs in water treatment are due to the use of electricity, and the water pumping stage is the biggest contributor to this consumption. Even though the price of the biocoagulant was identified as eight times that of aluminum sulfate, the water treatment cost with the biocoagulant was 21% higher compared to that with aluminum sulphate. In this regard, circular economy propositions for sludge valorization are discussed for use, recycling, or proper disposal. Thus, the environmental and economic analysis in this study offers insights into eco-efficiency promotion in water treatment and sludge management. Full article