Search Results (153)

The Adiabatic Sonic Evaporation and Crystallization (ASEC) technology was developed as a disruptive zero-liquid discharge system to treat contaminated mining effluents. This study evaluates its ecotoxicological efficacy using Lemna minor, a freshwater macrophyte, as a sensitive bioindicator. Acute growth inhibition tests were conducted using OECD Guideline 221. Lemna minor was exposed for 7 days to untreated and treated effluents from the Tharsis mine and the Tinto River in southern Spain. The results revealed 100% inhibition of frond growth and biomass in untreated samples (pH < 2.6), indicating acute toxicity. In contrast, effluents treated with ASEC showed growth and biomass accumulation statistically indistinguishable from the control, confirming the system’s efficiency in reducing toxicity and restoring water quality. These findings support the environmental viability of ASEC technology for mine and port effluent treatment. Full article

This study aims to evaluate the potential of Lemna minor (common duckweed) for the removal of galaxolide (HHCB) from polluted water, a compound commonly used in consumer products such as perfumes and detergents. The focus was to identify the optimal conditions for removal, determine the removal efficiency, and elucidate the mechanisms involved. The experiment was conducted by cultivating Lemna minor using as a cultivation medium synthetic sewage and laboratory solutions (MilliQ water) containing galaxolide at two levels of concentration (1034 µg·L⁻¹ and 2326 µg·L⁻¹). The plants were exposed to light for 16 h a day and grown at pH 5. Removal efficiency was assessed through liquid chromatography (HPLC) with fluorescence detection (FLD). Kinetics of observed process was modelled using a pseudo-first-order equation. The study of the HHCB decay mechanism included determining the contributions to the final effect of the following processes occurring simultaneously: sorption on the plant surface, photodegradation, and uptake by Lemna. The removal efficiency (RE%) of galaxolide by Lemna minor was 99.7% when aqueous standard solution was used as the cultivation medium after 14 days, and between 97.8% and 98.6% in the case of wastewater samples. Sorption onto plants surface, photodegradation, and uptake by the plants were identified as the primary mechanisms for HHCB removal. Toxicity studies revealed that galaxolide exposure adversely affected Lemna minor growth, altering photosynthetic pigments (chlorophyll and carotenoid) levels. Full article

4-Aminodiphenylamine (4-ADPA) is a common additive in rubber tires, known for its antioxidant properties. It plays a crucial role in enhancing tire durability by preventing issues such as drying, cracking, and degradation from prolonged exposure to environmental factors like heat, oxygen, and ozone. However, despite its advantages in extending tire lifespan, the use of 4-ADPA raises significant environmental concerns. As tires wear down, microscopic tire wear particles (TWPs) containing 4-ADPA are released into the environment with substantial leaching, contaminating the waterways. The 4-ADPA leachates pollute and pose a threat to aquatic ecosystems, affecting various forms of marine life. The current study investigates the ecotoxicological effects of 4-ADPA on the aquatic plant Lemna minor (L. minor), focusing on its impact on relative growth and physiological biomarkers. Several parameters were assessed to evaluate ecotoxicity, including frond morphology, fresh biomass, total frond number, chlorophyll content, and starch accumulation. L. minor was grown for 7 and 14 days under controlled laboratory conditions using Hoagland media with varying concentrations of 4-ADPA (10–100 μg/L), while a control group was maintained in media without 4-ADPA. The results indicate that exposure to 4-ADPA led to a dose-dependent reduction in fresh biomass, total frond number, and chlorophyll levels. Lugol’s staining revealed increased starch accumulation in the fronds after exposure to 4-ADPA. The biological effects observed in L. minor following exposure to 4-ADPA, even at environmentally relevant concentrations, demonstrate a significant ecotoxicological impact on aquatic ecosystems. Further research involving additional species and investigating the mechanisms behind 4-ADPA toxicity is recommended to better understand its long-term consequences. Full article

The work aims to apply cheap and widely accessible tools based on artificial intelligence to analyze, group, and categorize a large amount of available research literature (from a massive bibliographic search) on the use of Lemna minor for animal feed, not only comprehensively and objectively, but also in a more effective and less time-consuming way. In addition, a comprehensive and critical summary was conducted to highlight recent applications of L. minor in animal feed. The Scopus database was used for the original bibliographic search. Then, a newly developed online and freely available tool called “Jupyter Notebook on Google Colab” was applied to cluster the large volume of bibliographic data (1432 papers) obtained in the basic search, which allowed their reduction until only 148 papers. These papers were reviewed in a traditional way obtaining relevant information about L. minor production, nutritional value, composition, and its application as animal feed. In this sense, the most successful applications were for fish and poultry feeding, reaching levels of inclusion of 15–20% in fish and 5–15% in poultry. It is of great interest because of the expected increase in prices of conventional sources of protein for animal feed. Full article

The production of duckweed (Lemnaceae) as a novel protein source could make a valuable contribution to human nutrition. The greatly reduced habitus of duckweed enables simple cultivation with extremely low space requirements, making this free-floating freshwater plant ideal for substrate-free and vertical cultivation in controlled environment agriculture. Of particular importance in the design of a plant-producing Indoor Vertical Farming process is the determination of light intensity, as artificial lighting is generally the most energy-intensive feature of daylight-independent cultivation systems. In order to make the production process both cost-effective and low emission in the future, it is, therefore, crucial to understand and mathematically describe the primary metabolism, in particular the light utilization efficiency. To achieve this, a growth model was developed that mathematically describes the combined effects of plant density and light intensity on the growth rate of Lemna minor L. and physiologically explains the intraspecific competition of plants for light through mutual shading. Furthermore, the growth model can be utilized to derive environmental and process parameters, including optimum harvest quantities and efficiency-optimized light intensities to improve the production process. Full article

This study evaluates the effects of caffeine (CAF) on the bacteria Aliivibrio fischeri, the microalga Raphidocelis subcapitata, the macrophyte Lemna minor, and the larvae of Chironomus riparius, aiming to understand its environmental impact and contribution to ecological risk assessment. Bioluminescence inhibition in A. fischeri (EC₅₀ = 998.5 mg/L) and growth inhibition in R. subcapitata and L. minor (EC₅₀ = 60.1 mg/L and EC₅₀ = 649.2 mg/L, respectively) were observed. For L. minor, reduced catalase (CAT) activity and non-linear responses in glutathione S-transferases (GSTs) were recorded. No significant changes were observed in proline, malondialdehyde (MDA), and pigment contents. In C. riparius, acute mortality (LC₅₀ = 644.5 mg/L) was observed, and growth was significantly affected after 10 days of CAF exposure (EC₅₀ = 81.62 mg/L for fresh biomass). After 10 days of exposure, there was an increase in CAT activity and thiobarbituric acid reactive substances, with TBARS levels both at concentrations ≥82.64 mg/L, and a decrease in GSTs (92.18 mg/L) and acetylcholinesterase (AChE) (≤62.09 mg/L) activities of C. riparius. The results show that CAF exposure affects organisms’ metabolic and physiological functions, with varying sensitivities among species, potentially leading to ecological disturbances in aquatic ecosystems. The hazardous concentration for 5% of species was 4.42 mg/L. Long-term studies are necessary to understand the risk of caffeine under more realistic scenarios. Full article

The constant increase in industrialization and urbanization has led to the regular discharge of wastewater into the environment in excessive amounts, which has caused significant impacts on both human and wildlife ecosystems. The sustainable management and treatment of wastewater, whether of industrial or domestic origin, represents a crucial challenge in this century. In this study, phytoremediation was employed as a wastewater treatment strategy using two species of aquatic macrophytes: water hyacinth (Eichhornia crassipes) and duckweed (Lemna minor). The study was conducted over seven consecutive evaluation periods, with five-day intervals between each. The objective was to apply the multivariate HJ-Biplot methodology to evaluate the effects of phytoremediation of two species of aquatic microphytes on the physicochemical characteristics of wastewater from Milagro canton, Ecuador. Additionally, a microbiological analysis was conducted to determine the effectiveness of the floating macrophytes. The analysis was based on the measurement of various physicochemical parameters, such as pH, electrical conductivity (EC), dissolved oxygen (DO), oxidation–reduction potential (ORP), salinity, total dissolved solids (TDSs), biochemical oxygen demand (BOD), chemical oxygen demand (COD), hardness, and temperature. The results showed that the highest efficiency in pollutant removal was achieved with duckweed (Lemna minor) in five out of nine measured parameters, suggesting that this species was the most effective compared to the control sample and Eichhornia crassipes. The capacity of these macrophytes for wastewater treatment was confirmed by this study. To ensure effective water purification, timely extraction of aquatic macrophytes from water bodies is recommended. If this collection is not properly carried out, the nutrients absorbed and stored in the plant tissues may be released back into the aquatic environment due to plant decomposition. Full article

This review seeks to highlight the issue of utilizing a widely distributed aquatic species within the broader context of the transition from a linear to a circular economy and the growing emphasis on environmental sustainability. To promote a cleaner aquatic environment and ensure compliance with current regulations, the use of bioindicators and plant bioaccumulators presents a viable alternative. Lemna minor, a small aquatic species, serves as a noteworthy example that warrants greater consideration. A review of specialized literature was conducted to provide a comprehensive overview of these issues, drawing from the most relevant sources. This paper offers a broad discussion on bioeconomy and water management, along with an in-depth examination of L. minor, its characteristics, and its practical applications. The biological characteristics, ecological significance, and useful applications of L. minor in wastewater treatment, bioenergy, and bioproduct production are summarized in this research. The analysis also identifies research gaps for further investigation and looks at how this plant fits into new frameworks for the circular economy. Full article

The ozonation of norfloxacin (NOF), a widely used fluoroquinolone antibiotic, in the presence of Na⁺, Fe²⁺, Cu²⁺, Ni²⁺, and Co²⁺ cations and their montmorillonite-supported counterparts was investigated. The NOF degradation and the toxicity of the ozonized mixtures towards an aquatic organism (Lemna minor) were evaluated in terms of changes in its frond number, chlorophyll content, photosynthesis efficacy, and production of reactive oxygen species (ROS). The evolution over time of the NOF degradation grade and the toxicity were discussed in terms of i. the observed changes in the interactions of the cation and clay catalyst with NOF molecules; ii. the pH decay, during ozonation. Ion-exchange and Lewis acid–base interactions appear to govern NOF adsorption and clay catalyst dispersion in correlation with the progressive formation of acidic species in the aqueous media. These findings reveal promising prospects for tailoring optimum oxidative water treatments with minimum toxicity and for predicting their environmental impacts on aquatic media. Full article

Although the coking industry is a major polluter, it is still an important and irreplaceable industry in many countries. Wastewater from the coking industry typically contains large amounts of various hazardous substances, including phenols, cyanides, and thiocyanates; we conducted a comprehensive study on their ecotoxicity. This included five different toxicity tests with common species from different trophic levels: the bacteria Aliivibrio fischeri and Pseudomonas putida, the microalgae Chlorella sp., the duckweed Lemna minor, and the onion plant Allium cepa. These tests have rarely or never been used for these three toxicants. The results show that cyanide generally has the highest toxicity, while phenol has a relatively equal or higher toxicity than thiocyanate, depending on the test. Since no data on the joint toxic action of these three toxicants can be found in the literature, and although their joint occurrence in the aquatic environment is very likely, we performed joint toxic action analysis. The analysis was performed for binary and ternary mixtures of the toxicants using the Aliivibrio fischeri test. The concentration addition model was used as a reference model for the toxic behavior of these mixtures. The results obtained showed a synergistic deviation from the concentration addition model for combinations of phenol with cyanide and with thiocyanate, while the combination of cyanide and thiocyanate led to additive toxic behavior. Full article

Effective wastewater management is a critical environmental challenge, particularly in industrial regions like Faisalabad, where untreated textile effluents contribute to severe water pollution. This study evaluates the potential of phytoremediation using floating aquatic plants—Eichhornia crassipes (water hyacinth), Pistia stratiotes (water lettuce), and Lemna minor (common duckweed)—for the treatment of industrial textile wastewater. A controlled laboratory-scale experiment was conducted to assess pollutant removal efficiency over a 10-day retention period. The initial effluent concentrations of key parameters were measured before treatment to establish baseline conditions. The results demonstrated that Eichhornia crassipes exhibited the highest removal efficiency, achieving reductions of 36.12% (TDS), 36.14% (EC), 36.30% (salinity), 6.12% (pH), 34.30% (total hardness), and 44.52% (chloride). Furthermore, Pistia stratiotes and Lemna minor were particularly effective in removing nitrate (99.76%), ammonium (52.11%), and sodium adsorption ratio (46.29%), indicating species-specific phytoremediation potential. These findings highlight the viability of a low-cost, eco-friendly, and sustainable nature-based solution for wastewater treatment in industrial clusters, offering a practical alternative to conventional treatment technologies. Full article

This study aimed to evaluate the degree of contamination of water matrices (deionised water, spring water, tap water) in a 14-week experiment using film samples from commercial bags printed with water- and solvent-based inks. The effect of different lighting conditions on leaching and ecotoxicity was also investigated. Samples were exposed for 24 h to natural sunlight and to no light in a darkroom. A significant increase in contaminants in the aqueous matrices was observed in regard to the 12-week leaching potential of the components from the films in regard to all the lighting variants and aqueous matrices analysed: an increase in dissolved organic carbon (DOC), total organic carbon (TOC), and total suspended solids (TSS). Based on the procedures carried out, the relationship between the lighting conditions and the amount of the constituents released into the aqueous matrices was not confirmed. The concentration of total organic carbon in all the samples peaked between weeks 6 and 9 of the study, followed by a gradual reduction in leaching. This phenomenon could be linked to the gradual depletion of the substances present in the samples or to the achievement of a concentration equilibrium between the aqueous matrix and the sample and/or to the formation of deposits on the surface of the films, which hindered the migration of the substances into the solutions. Ecotoxicity tests performed between 7 and 14 weeks showed most samples’ toxic and highly toxic effects on the growth of Lemna minor fronds and Sinapis alba/Lepidium sativum roots. In contrast, no toxic effects were observed in regard to most of the samples during screening mortality tests on Daphnia magna and Artemia salina. This study highlights the need for further research into the effects of plastic pollution on the aquatic environment. Full article

Potentially toxic metals contaminate the environment and threaten human health. This study investigated the effect of chelator citric acid (CA) on enhancing metals (Cu, Ni and/or Pb) accumulation in duckweed (Lemna minor). Lemna minor were cultured in solutions with single or mixed metals (Ni 50 ppm, Cu 50 ppm and/or Pb 10 ppm) added with different levels of CA (0 ppm, 10 ppm, 50 ppm or 100 ppm CA) for 4 weeks, then harvested, dried and digested. For single-metal solutions, duckweed treated with higher levels of CA (50 ppm or 100 ppm CA) accumulated more Ni or Cu; 100 ppm CA increased Cu and Ni accumulation in plants by 96% and 120%. Meanwhile, 10 ppm CA, 50 ppm or 100 pm CA had similar effects on improving Pb accumulation in duckweed, which enhanced Pb accumulation in duckweed by 100%. For duckweed cultured in mixed-metals solutions, 50 ppm and 100 ppm CA still significantly increased the amounts of Cu and Ni in duckweed by 50% and 100%, while Pb sequestration was not enhanced. The role of CA in increasing metal accumulation in duckweed depended on the levels of CA, the concentrations and types of metals. Future studies are needed to further investigate the potential of CA to assist phytoremediation of different metals contaminated environment. Full article

The addition of carbon nanotubes (CNTs) to cement matrix brings multiple beneficial effects ranging from improving mechanical and physical properties to the creation of smart materials. When subjected to an erosive environment or as end-of-life waste, mortars with CNT addition might get released into the environment and come in contact with surface waters. The assessment of the environmental impact of mortars reinforced with carbon nanotubes is an important factor concerning their sustainability, as it has not yet been addressed in the literature. The presented paper aims to assess the water toxicity of cement mortars with various dosages of 0.05 wt.%, 0.1 wt.%, and 0.2 wt.% of carbon nanotube. The effect of the quality of water dispersion of CNTs was also considered through two sonication times of the suspension: 20 min and 60 min. Tests using indicator organisms, Aliivibrio fischeri, Daphnia magna, and Lemna minor, were conducted on shredded and non-shredded mortars. The results reveal no to low toxicity for all tested mortars under the assumed framework of toxicity assessment. The toxicity results for samples containing CNTs were comparable to those without CNTs, indicating that the toxicity of mortars incorporating CNTs is not greater than that of conventional cement-based materials. The water toxicity of the cement mortars is rather connected with the washing away of the hydration products more than with the presence of carbon nanotubes. Full article

Duckweeds—a group of floating leaf macrophytes from the family of Lemnaceae—have become a major area of interest in the fields of basic and applied aquatic sciences in recent decades, including their use in water purification. Aiming to fulfill one of the gaps in the role of light intensity in duckweed efficiency in organic matter removal, we carried out a laboratory experiment with the use of two duckweed species: Lemna minor and Spirodela polyrhiza. Our main finding was that the intensity of light has a positive effect on the process of water purification from organic compounds by Lemna minor. However, this was not applicable to Spirodela polyrhiza due to the fact that the growth of the species was inhibited by high light intensities. Full article