Phytodegradation potential of bisphenolA from aqueous solution by Azolla Filiculoides

Three-Dimensional Printed Filters Based on Poly(ethylene glycol) Diacrylate Hydrogels Doped with Silver Nanoparticles for Removing Hg(II) Ions from Water

Nowadays, due to water pollution, more and more living beings are exposed to dangerous compounds, which can lead to them contracting diseases. The removal of contaminants (including heavy metals) from water is, therefore, a necessary aspect to guarantee the well-being of living beings. Among the most used techniques, the employment of adsorbent materials is certainly advantageous, as they are easy to synthesize and are cheap. In this work, poly(ethylene glycol) diacrylate (PEGDA) hydrogels doped with silver nanoparticles (AgNPs) for removing Hg(II) ions from water are presented. AgNPs were embedded in PEGDA-based matrices by using a photo-polymerizable solution. By exploiting a custom-made 3D printer, the filters were synthesized. The kinetics of interaction was studied, revealing that the adsorption equilibrium is achieved in 8 h. Subsequently, the adsorption isotherms of PEGDA doped with AgNPs towards Hg(II) ions were studied at different temperatures (4 °C, 25 °C, and 50 °C). In all cases, the best isotherm model was the Langmuir one (revealing that the chemisorption is the driving process and the most favorable one), with maximum adsorption capacities equal to 0.55, 0.57, and 0.61 mg/g, respectively. Finally, the removal efficiency was evaluated for the three temperatures, obtaining for 4 °C, 25 °C, and 50 °C the values 94%, 94%, and 86%, respectively.

Advanced oxidation process (AOP) combined biological process for wastewater treatment: A review on advancements, feasibility and practicability of combined techniques

Complexity of wastewater is the most challenging phenomenon on successful degradation of pollutant via any wastewater treatment regime. Upon availability of numerous techniques, Advanced Oxidation Processes (AOP) is the most promising technique for treating industrial wastewater. Higher operating cost is the most promising factor that possess challenge for the industrial scale usage of the AOP process. Combination of biological process with AOP helps in achieving sustainable degradation of toxic pollutant in the wastewater. AOP result in complete or partial degradation of toxic emerging pollutants with the help of free radicals like hydroxyl, superoxide, hydroperoxyl and sulphate radicals. In addition to this the presence of bio-enzymes and microorganisms helps in sustainable degradation of pollutant in an economical and environmentally friendly strategy. In this review, a detailed discussion was conducted on various AOP, focusing on catalytic ozonation, electrochemical oxidation, Sono chemical and photocatalytic processes. With the need for sustainable solutions for wastewater treatment, the use of AOP in conjunction with biological process has innumerous opportunities for not only wastewater treatment but also the production of high value by-products. Further, the effect of AOP combined biological processes needs to be analyzed in real time for the different concentration of industrial wastewater and their benefits needs to be explored in future towards achieving SDGs.

Evaluation of Azolla filiculoides potential in pyrene and phenanthrene accumulation and phytoremediation in contaminated waters

Polycyclic aromatic hydrocarbons (PAHs) are a serious threat to the health of the environment. This study investigated the potential of Azolla filiculoides for the uptake, accumulation, and biodegradation of phenanthrene and pyrene. A- filiculoides plants were treated with 10 and 30 mg L-1 concentrations of phenanthrene and pyrene for the experimental duration of ten days. Phenanthrene and pyrene concentrations were measured using the high-performance liquid chromatography (HPLC) technique. Identification of the intermediate by-products resulting from the biological degradation of PAHs was performed by gas chromatography-mass spectrometry (GC/MS). The quantities of phenanthrene and pyrene in the ten-day treatments with 10 and 30 mg L-1 were 0.007 and 0.011 mg g-1 FW, and 0.048 and 0.079 mg g-1 FW, respectively. The growth parameters in the plants such as fresh weight, dry weight and RFN as well as the content of photosynthetic pigment of the plant decreased significantly compared to the control sample (p < 0.05). Ten compounds were identified from the plant tissue during the decomposition of pyrene and phenanthrene, and none of the PAHs were identified in the aquatic environment. Therefore, the use of A-filiculoides for phytoremediation of water resources contaminated with PAHs is an effective and promising method.

Visible-light-driven photocatalytic dual-layer hollow fibre membrane ameliorates the changes of bisphenol A exposure in gastrointestinal tract

Various treatments of choice are available to overcome contamination of bisphenol A (BPA) in the environment including membrane technologies; however, the treatment still releases contaminants that threaten the human being. Therefore, the present study is conducted to investigate the degradation of BPA by recently developed visible-light-driven photocatalytic nitrogen-doping titanium dioxide (N-doped TiO₂) dual-layer hollow fibre (DLHF) membrane and its efficiency in reducing the level of BPA in contaminated water. Fabricated with suitable polymer/photocatalyst (15/7.5 wt.%) via co-extrusion spinning method, the DLHF was characterized morphologically, evaluated for BPA degradation by using submerged photocatalytic membrane reactor under visible light irradiations followed by the investigation of intermediates formed. BPA exposure effects were accessed by immunohistochemistry staining of gastrointestinal sample obtained from animal model. BPA has been successfully degraded up to 72.5% with 2 intermediate products, B1 and B2, being identified followed by total degradation of BPA. BPA exposure leads to the high-intensity IHC staining of Claudin family which indicated the disruption of small intestinal barrier (SIB) integrity. Low IHC staining intensity of Claudin family in treated BPA group demonstrated that reducing the level of BPA by N-doped TiO₂ DLHF is capable of protecting the important component of SIB. Altogether, the fabricated photocatalytic DLHF membrane is expected to have an outstanding potential in removing BPA and its health effect for household water treatment to fulfil the public focus on the safety of their household water and their need to consume clean water.

Phytoremediation potential, antioxidant response, photosynthetic behavior and rhizosphere bacterial community adaptation of tobacco (Nicotiana tabacum L.) in a bisphenol A-contaminated soil

Bisphenol A (BPA) is an emerging organic pollutant, widely distributed and frequently detected in soil in recent years. BPA toxicity is a problem that needs to be solved in terms of both human health and agricultural production. Up to now, the toxic effect of BPA and its mechanism of action on plants, as well as the possibility of using plants to remediate BPA-contaminated soil, remain to be explored. In this study, six treatment groups were set up to evaluate the effects of different concentrations of BPA on the germination and growth of tobacco (Nicotiana tabacum L.) by medium experiments. Furthermore, the representative indexes of photosynthetic and antioxidant system were determined. Meanwhile, tobacco seedlings were cultivated in soil to further explore the effects of BPA on rhizosphere soil enzyme activity and bacterial community structure with or without 100 mg/kg BPA exposure. The enhancement of BPA removal efficiency from soil by phytoremediation using tobacco plants would also be estimated. Our results showed that high doses of BPA in solid medium remarkably inhibited tobacco seedling growth, and its toxicology effect was positively correlated with BPA concentration, while lower BPA exposure (< 20 mg/L) had little limitation on tobacco growth and induced hormesis effect, which was reflected mainly in the increase of root length. In pot experiments, the reducing of chlorophyll content (36.4%) and net photosynthetic rate (41.2%) meant the inhibition of tobacco photosynthetic process due to high concentration of BPA exposure (100 mg/kg) in soil. The increase of H2O2 and O2- content suggested that BPA could destroy the balance of reactive oxygen species (ROS) in plants. However, tobacco plants still presented a high removal efficiency of BPA at the concentration of 100 mg/kg in soil, which could reach to 80% within 30 days. Furthermore, it was indicated that tobacco cultivation changed the structure of rhizosphere soil bacterial communities and the relative abundance of some valuable strains, including Proteobacteria, Acidobacteria and other strains, which might be participated in the BPA removal process. In addition, the tobacco-soil microbial system had the potential to reverse the negative effects caused by BPA through stimulating microorganism associated with soil nutrient cycling. In summary, tobacco is a competitive plant in phytoremediation of BPA-contaminated soil, though the growth of tobacco could be inhibited at high concentration of BPA. Moreover, tobacco might promote the removal efficiency of BPA by regulating the rhizosphere bacteria communities.

Bisphenol-A incite dose-dependent dissimilitude in the growth pattern, physiology, oxidative status, and metabolite profile of Azolla filiculoides

Bisphenol-A (BPA) is a ubiquitous environmental pollutant affecting the growth and development of aquatic macrophytes. The present study was designed to evaluate the toxic effect of BPA on Azolla filiculoides. The plants were exposed to different concentrations of BPA and the effect was evaluated in terms of plant growth, physiological and oxidative status, responses of the antioxidative system, and changes in key metabolites. The results have shown that BPA (≥ 20 mg L^-1) incites a significant reduction in frond number, frond surface area, and growth rate of the plants along with severe frond damage, membrane peroxidation, and electrolyte leakage. Moreover, at higher concentrations, a significant reduction in the content of chlorophylls and carotenoids was observed, which was further amplified with the duration of treatments. Furthermore, excessive generation of O₂^•- and H₂O₂ invoked the antioxidative machinery under BPA exposure. However, sufficient activity of the antioxidative enzymes was observed in plants treated with ≤ 10 mg L^-1 of BPA. The untargeted metabolome profile revealed modulation of 29 metabolites including amino acids, sugar alcohols, organic acids, and phenolics in response to BPA. An increased amount of asparagine, lysine, serine, tryptophan, tyrosine, and valine after 3 days of BPA exposure indicates their role in providing better stress tolerance. Therefore, the experimental findings suggest that A. filiculoides responds differently to BPA exposure. Higher BPA concentrations (≥ 20 mg L^-1) documented a greater impact in terms of plant physiology and metabolism whereas, the effect was minimal at lower concentrations (≤ 10 mg L^-1).

Adsorptive Removal of Azithromycin Antibiotic from Aqueous Solution by Azolla Filiculoides-Based Activated Porous Carbon

Due to the shortage of freshwater availability, reclaimed water has become an important source of irrigation water. Nevertheless, emergent contaminants such as antibiotics in reclaimed water can cause potential health risks because antibiotics are nonbiodegradable. In this paper, we report the adsorptive removal of azithromycin (AZM) antibiotics using activated porous carbon prepared from Azolla filiculoides (AF) (AFAC). The influence of the adsorption process variables, such as temperature, pH, time, and adsorbent dosage, is investigated and described. The prepared AFAC is very effective in removing AZM with 87% and 98% removal after the treatment of 75 min, at 303 and 333 K, respectively. The Langmuir, Temkin, Freundlich, and Dubinin–Radushkevich isotherm models were used to analyze the adsorption results. The Freundlich isotherm was best to describe the adsorption isotherm. The adsorption process follows second-order pseudo kinetics. The adsorption was endothermic (ΔH°= 32.25 kJ/mol) and spontaneous (ΔS° = 0.128 kJ/mol·K). Increasing the temperature from 273 to 333 K makes the process more spontaneous (ΔG° = −2.38 and −8.72 KJ/mol). The lower mean square energy of 0.07 to 0.845 kJ/mol confirms the process’ physical nature. The results indicate that AFAC can be a potential low-cost adsorbent of AZM from aqueous solutions.

Modeling of wastewater treatment by Azolla filiculoides using response surface methodology

INTRODUCTION

Due to the population growth and reduction of water resources, wastewater treatment and reuse vital. As the secondary wastewater treatment processes enable removes a significant amount of P and N, nutrient-rich effluents can cause eutrophication in water bodies. On the other hand, nutrients removal in sewage treatment using mechanical methods is costly and complex. The aquaculture method using Azolla filiculoides could be an appropriate option for removing total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD) from wastewater.

MATERIALS AND METHODS

Synthetic wastewater has been prepared in the typical range of municipal wastewater. Two g fresh weight of an acclimatized A.filiculoides was floated in sample bowls each one containing 500 CC prepared wastewater. Total nitrogen, TP, and COD removal by Azolla filiculoides for 21-days were optimized and investigated using the response surface methodology (RSM). For this aim, the D-optimal method was used to optimize the three independent variables (TP concentration (10.8-84.6 mg l- 1), TN concentration (20-99 mg l- 1), and COD concentration (66.26-415 mg l- 1)) for their maximum removal efficiency of them. Experiments were performed on 28 runs in which independent variables were measured using a HACH DR 5000 spectrometer.

RESULTS

Predicted R-squared for COD, TP, TN removal, and Azolla mass (responses) have been equal to -0.0897, 0.8514, 0.7779, and 0.5645, respectively. The model was used to maximize Azolla growth and maximize removal efficiency of nitrogen, phosphorus, and COD that occurred in minimum concentrations of TN (20 mg l- 1), TP (10.8 mg l- 1), and COD (66.26 mg l- 1). The removal efficiency of Azolla was obtained 77.5 % for COD, 66.8 % for TP, and 78.1 % for TN in the optimum condition of independent variables. Also, increase of Azolla mass was 239 %, with desirability of 0.66. The difference between model prediction and model validation testing for Azolla mass increase, COD, TN, and TP removal was equal to ± 11.6 %, ± 7.9 %, ± 0.0 %, and ± 1.9 %, respectively.

CONCLUSIONS

Azolla could remove phosphorus in nitrogen deficiency or even lack of nitrogen. Results indicate that removal efficiency has an upward trend as the Azolla growth increases. This kind of fern has a significant effect on removing nitrogen, phosphorus, and COD from an aqueous solution. The removal efficiency of TN, TP, and COD at optimum operating conditions showed good agreement with model-predicted removal efficiency.

Enhanced Phytoremediation of Bisphenol A in Polluted Lake Water by Seedlings of Ceratophyllum demersum and Myriophyllum spicatum from In Vitro Culture

Bisphenol A (BPA) is a typical endocrine disruptor that causes problems in waters all around the world. In this study, the effects of submerged macrophytes (Ceratophyllum demersum and Myriophyllum spicatum) cultured in vitro on the removal of BPA at two initial concentrations (0.5 mg L⁻¹ vs. 5.0 mg L⁻¹) from Donghu lake water were investigated, using different biomass densities (2 g L⁻¹ vs. 10 g L⁻¹) under different nutrient conditions (1.85 mg L⁻¹ and 0.039 mg L⁻¹ vs. 8.04 mg L⁻¹ and 0.175 mg L⁻¹ of the total nitrogen and phosphorus concentration, respectively), together with the effect of indigenous microorganisms in the water. The results showed that indigenous microorganisms had limited capacity for BPA removal, especially at higher BPA initial concentration when its removal rate amounted to about 12% in 12 days. Addition with plant seedlings (5 cm in length) greatly enhanced the BPA removal, which reached 100% and over 50% at low and high BPA initial concentration in 3 days, respectively. Higher biomass density greatly favored the process, resulting in 100% of BPA removal at high BPA initial concentration in 3 days. However, increases in nutrient availability had little effect on the BPA removal by plants. BPA at 10.0 mg L⁻¹ significantly inhibited the growth of M. spicatum. Therefore, C. demersum may be a candidate for phytoremediation due to greater efficiency for BPA removal and tolerance to BPA pollution. Overall, seedlings of submerged macrophytes from in vitro culture showed great potential for use in phytoremediation of BPA in natural waters, especially C. demersum.

Bisphenol A removal by the Chlorophyta Picocystis sp.: optimization and kinetic study

The Chlorophyta Picocystis sp. isolated from a Tunisian household sewage pond appears promising for effective removal of Bisphenol A (BPA). Efficient and cost-effective technology for contaminants remediation relies on a tradeoff between several parameters such as removal efficiency, microorganism growth, and its tolerance to contaminant toxicity. This article demonstrates the optimum conditions achieving the highest removal rates and the minimal growth inhibition in batch cultures of Picocystis using response surface methodology. A central composite face-centered (CCF) design was used to determine the effects on removal and growth inhibition of four operating parameters: temperature, inoculum cell density, light intensity, and initial BPA concentration. Results showed that the maximal BPA removal was 91.36%, reached the optimal culture conditions of 30.7 °C, 25 × 10⁵ cells ml^-1 inoculum density, 80.6 µmol photons m^-2 s^-1 light intensity, and initial BPA concentration of 10 mg l^-1. Various substrate inhibition models were used to fit the experimental data, and robustness analysis highlighted the Tessier model as more efficient to account for the interaction between Picocystis and BPA and predict removal efficiency. These results revealed how Picocystis respond to BPA contamination and suggest that optimization of experimental conditions can be effectively used to maximize BPA removal in the treatment process.HighlightsSurface response methodology was applied for optimization of BPA removal by the Chlorophyta Picocystis sp.Temperature, light intensity, inoculum cell density and initial BPA concentration were selected as factors that may affect BPA removal and microalgae growth.The optimal conditions for the maximum BPA removal and minimum growth inhibition were 30.7 °C; 80.6 µmol photons m^-2 s^-1; 25 × 10⁵ cells ml^-1 and 10 mg l^-1 BPA.Teissier model was selected to fit the kinetic of BPA removal by Picocystis with R² = 0.92.

Visible-Light Active Photocatalytic Dual Layer Hollow Fiber (DLHF) Membrane and Its Potential in Mitigating the Detrimental Effects of Bisphenol A in Water

The presence of bisphenol A (BPA) in various water sources has potentially led to numerous adverse effects in human such as increased in blood pressure and derangement in liver function. Thus, a reliable treatment for the removing BPA is highly required. This present work aimed to study the efficiency of visible light driven photocatalytic dual-layer hollow fiber (DLHF) membrane for the removal of BPA from water and further investigated its detrimental effects by using an in-vivo model. The prepared membranes were characterized for their morphology, particles distribution, surface roughness, crystallinity and light absorption spectra. The removal of 81.6% and 86.7% in BPA concentration was achieved for N-doped TiO₂ DLHF after 360 min of visible and UV light irradiation, respectively. No significant changes for all three groups were observed in liver function test meanwhile the rats-exposed to untreated BPA water shows significance blood pressure increment contrary to rats-exposed to treated BPA water. Similarly, the normal morphology in both jejunum and ileum were altered in rats-exposed to untreated BPA water group. Altogether, the presence of N-doped TiO₂ in DLHF are shown to significantly enhance the photocatalytic degradation activity under visible irradiation, which effectively mitigates the effect of BPA in an in-vivo model.

Phytoremediation potential of switchgrass (Panicum virgatum), two United States native varieties, to remove bisphenol-A (BPA) from aqueous media

Plastic wastes burdening Earth’s water and accumulating on land, releasing toxic leachates, are one of the greatest global threats of our time. Bisphenol-A (BPA), a potent endocrine disrupting compound, is a synthetic ingredient of the polycarbonate plastics and epoxy resins used in food containers, cans, and water bottles. Bisphenol-A’s rising concentrations in the environment require a sustainable alternative to current removal practices, which are expensive and/or ecologically unsafe. Switchgrass offers a safe alternative. To investigate its potential for BPA removal, two United States native switchgrass varieties where tested in hydroponic media. Results show minimal hydrolysis and photolysis of BPA over 55 days, confirming its persistence. Both generic and heavy metal switchgrass exhibited statistically significant (p < 0.0001) BPA removal (40% and 46%, respectively) over approximately 3 months, underscoring switchgrass’s effectiveness for BPA removal. Significantly higher (p < 0.005) BPA accumulation in roots than shoots and nonsignificant variances in biomass, chlorophyll (p > 0.19), and peroxidase between BPA-treated and untreated plants indicates substantial BPA tolerance in both varieties. Kinetic parameters of BPA removal and translocation factors were also determined, which will inform the design of BPA removal phytotechnologies for a variety of soil conditions, including landfills where BPA accumulation is greatest.

Removal of emerging contaminants daidzein and coumestrol from water by nanozeolite beta modified with tetrasubstituted ammonium cation

In present research, a simplistic hydrothermal method was adopted for one-step synthesis of nanozeolite beta (NZB) having an average particle size of 18nm with Si/Al ratio 46.67, surface area 328m²/g, pore volume 0.287cm³/g, and pore diameter 3.5nm. The surface of the synthesized NZB was modified with 0.5wt% hexadecyltrimethylammonium bromide (HDTMA-Br) and used as an adsorbent for the removal of two phytoestrogens daidzein and coumestrol from aqueous solutions. The surface properties and surface charge of NZB considerably changed after modification with HDTMA-Br, which resulted in enhanced removal of daidzein (92-98% from 7 to 27%) and coumestrol (93.5-99% from 5 to 9.2%). The surface modified zeolite beta (SMZB) has similar physical characteristics as of NZB with an average particle size of 20nm, surface area 299.8m²/g, pore volume 0.263cm³/g, and pore diameter 3.51nm. The influence of various parameters was examined by conducting a sequence of batch experiments. The adsorption equilibrium was achieved in less than 3h with saturation capacity of 40.74mg/g and 42.87mg/g for daidzein and coumestrol, respectively. The Freundlich isotherm and fractional order kinetic models represented the adsorption data very closely. The thermodynamic parameters indicated that sorption of both phytoestrogens onto SMZB is spontaneous and exothermic.

Bisphenol A Removal by Submerged Macrophytes and the Contribution of Epiphytic Microorganisms to the Removal Process

Bisphenol A (BPA), a typical endocrine disruptor, has been found in global aquatic environments, causing great concern. The capabilities of five common submerged macrophytes to remove BPA from water and the contributions of epiphytic microorganisms were investigated. Macrophytes removed 62%-100% of total BPA (5 mg/L) over 12 days; much higher rates than that observed in the control (2%, F = 261.511, p = 0.000). Ceratophyllum demersum was the most efficient species. C. demersum samples from lakes with different water qualities showed no significant differences in BPA removal rates. Moreover, removal, inhibition or re-colonization of epiphytic microorganisms did not significantly change the BPA removal rates of C. demersum. Therefore, the contributions of epiphytic microorganisms to the BPA removal process were negligible. The rate of BPA accumulation in C. demersum was 0.1%, indicating that BPA was mainly biodegraded by the macrophyte. Hence, submerged macrophytes, rather than epiphytic microorganisms, substantially contribute to the biodegradation of BPA in water.