Biosorption Capacity Research Articles

Exploring biosorption potential of cow dung derived novel strain Cellulosimicrobium cellulans KHP3 in the remediation of Chromium (Cr), Copper (Cu) and Zinc (Zn)

The present work reports the bioremediation ability of cow dung isolated bacterial strain Cellulosomicrobium cellulans KHP3 identified by applying PCR amplification and rRNA gene sequencing. The potential of C. cellulans KHP3 to tolerate different concentrations of heavy metals was investigated by growing the novel strain on nutrient agar medium supplemented with increasing concentrations (in ppm) of heavy metals i.e., Chromium (50–1500) Copper (50–200), and Zinc (50–200). The strain KHP3 displayed maximum tolerable concentration (MTC) of 1500 ppm against Chromium while 200 ppm was observed for Copper and Zinc. The strain KHP3 was found to be very effective in the removal of Chromium as indicated by 59.8% removal percentage followed by Zinc (36.6%) and Copper (20.4%) after 72 h of incubation at 37 °C. The higher biosorption capacity of our strain was achieved against Chromium (349.6 mg/g) followed by Zinc (198.8 mg/g) and Copper (58.6 mg/g) which reflects the potential of bacterial strain to absorb a greater amount of heavy metal ions. Following bioremediation assay, the strain C. cellulans KHP3 was subjected to FE-SEM coupled with EDS and FTIR to confirm surface morphological and physiochemical changes resulting from heavy metal adsorption. FE-SEM observation provided substantial information on the immobilization ofChromium, Copperand Zincions on the bacterial cell surface while EDS peaks revealed surface bio-sorption of these heavy metals. The binding of heavy metals on the surface of C. cellulans KHP3 was proved through FTIR study which revealed the involvement of various functional groups acting as surface ligand such as hydroxyl, carbonyl, and amine present on bacterial surface. Moreover, studies based on Freundlich, Langmuir, and Temkin isotherm models were also done to further validate the adsorption mechanism of our strain. The significant R 2 values of 0.9983 and 0.9852 observed in case of Chromium and Zinc respectively depicted monolayer adsorption. On the other hand, R 2 value 0.7959 in case of Copper significantly revealed multilayer adsorption mechanism. The findings highlight the biosorption ability of Cellulosomicrobium cellulans KHP3 for heavy metals that may be explored in the remediation of environmental pollutants.

Efficient biosorption of Zn(II), Cd(II), and Pb(II) by Aspergillus brasiliensis in industrial wastewater coupled with electrochemical monitoring via sensor enhanced with modified silver nanoparticles.

This work investigates the use of Aspergillus brasiliensis, this particular species of Aspergillus, as a biosorbent for the first time. It is employed to biosorption Zn(II), Cd(II), and Pb(II) and combines the biosorption experiments with electrochemical measurements for in situ analysis. For the experiments, a batch system was employed with the dead biomass. In order to determine the biosorption capacity, the impact of several operational parameters was examined, including pH, temperature, agitation speed, contact time, and initial metal concentration, and the optimum values were 5, 30°C, 150rpm, 2h, and 150ppm, respectively. Using 0.2g biomass in 100mL solution, the maximal uptake of Zn(II), Cd(II), and Pb(II) at ideal conditions was determined to be 33.67, 24.51, and 36.76, respectively. The Langmuir and Freundlich isotherm model was studied for the biosorption process. An electrochemical sensor using nanomaterials is designed and constructed to monitor the concentration of these metals. The silver nanoparticles functionalized with thiosemicarbazide and 6-mercaptohexanoic acid (mercaptohexanoylhydrazinecarbothioamide-coated silver nanoparticles, MHHC-AgNPs) linked to the carboxylated multi-walled carbon nanotubes (MWCNTs) were utilized for glassy carbon electrode modification (MHHC-AgNPs/MWCNTs/GCE). The concentration range of Zn(II) is 0.7-173µg/L, Cd(II) is 1.18-293µg/L, and Pb(II) is 2.17-540µg/L. The detection limits for Zn(II), Cd(II), and Pb(II) are 0.036µg/L, 0.15µg/L, and 0.16µg/L, respectively. Under optimized conditions, these results were obtained using the differential pulse anodic stripping voltammetry method (DPASV). The successful detection of Zn(II), Cd(II), and Pb(II) was achieved by effectively preventing interference from other common ions. It was effectively employed for measuring ions in industrial wastewater, and the results obtained aligned with those acquired from an atomic absorption spectrometer (AAS). Thus, Aspergillus brasiliensis species, along with this electrochemical sensor, can be used to remediate and monitor environmental pollution, Zn(II), Cd(II), and Pb(II), successfully.

Effectiveness of Musa Balbisiana bract toward chromium removal from industrial tannery effluent: optimization, kinetics, isotherms, regeneration, and cost estimation

Eradicating chromium from industrial effluent is essential for environmental security and economic reasons. This study investigates the potency of activated Musa balbisiana bract biomass as a biosorbent to remove hexavalent chromium (Cr6+) from real industrial tannery effluent (ITE). The characterization study exemplifies the existence of irregular structures and excessive cavities, and the occurrence of functional groups (hydroxyl, carboxyl, esters, and alkynes) are benefitting the deposition of Cr6+ on the biosorbent. A maximum biosorption capacity of 42.75 ± 0.21mg/g was observed at an optimum pH of 6.5, biosorbent dosage of 0.3g, initial Cr6+ concentration of 50mg/L, and contact time of 120min. The validation experiment confirmed the removal efficiency of total chromium, trivalent chromium, and Cr6+ 92.56 ± 0.80%, 98.63 ± 0.20%, and 96.21 ± 0.50%, respectively. Among the models, Langmuir isotherm (R2: 0.9992) and pseudo-second order (R2: 0.9999) kinetic models greatly correlate with the equilibrium data. A 2-tier membrane module was examined for continuous study and reached 88.23 ± 0.60% Cr6+ removal. Statistical analysis was performed to confirm the significance of adsorption results. The likelihood of the desorption and regeneration of the treated biosorbent was investigated. The estimated cost per volume of ITE treated and unit of pollutant removal from ITE employing Musa balbisiana bract biosorbent is around $3.08/m3 and $3.75/kg.

Uranium and arsenic bioremediation potential of plastic associated multi-metal tolerant Bacillus sp. EIKU23

Plastic waste accumulation is a significant environmental concern as it promotes microbial growth and acts as a carrier for heavy metals. This study focuses on a Bacillus sp. strain isolated from the surface of a used plastic bottle, tolerant to various potential toxic elements (PTEs) such as chromium, nickel, cobalt, copper, zinc, arsenite [As(III)], but sensitive to uranium (U) and arsenate [As(V)] toxicity. The strain demonstrates growth under different abiotic stress conditions, with the optimal pH range of 5.0-8.0 and a temperature of 30 °C. It shows remarkable removal capabilities, removing >23.3% of U, >38% of As(III)), and >22.6% of As(V) from an initial dose of 100mgL−1 in an aqueous solution. The biosorption capacity for U, As(III), and As(V) is 3.12, 3.1, and 1.8mgg−1 of biomass, respectively. Kinetic modelling suggests that the biosorption of U and As(V) follows a pseudo-second-order mechanism, while As(III) biosorption follows a pseudo-first-order mechanism. Moreover, the strain has the ability to precipitate >38.1% and ~67% of U using bacterially released phosphate from inorganic and organic sources, respectively. These findings highlight the strain's potential for bioremediation of PTE-contaminated environments, providing valuable insights for optimizing metal removal and immobilization processes in future research.

Mitigating Health Risks Through Biosorption: Effective Removal of Nickel (II) and Chromium (VI) from Water with Acid-Treated Potato Peels

Introduction: Nickel (Ni(II)) and chromium (Cr(VI)) are associated with serious health risks, including respiratory problems, kidney damage, and cancer, along with potential threats to ecosystems. Given their persistence and significant toxicity, effective removal from contaminated water is essential to mitigate these health risks. This study explores the efficacy of acid-treated potato peels (ATPP) as an economical and readily accessible biosorbent for the removal of Ni(II) and Cr(VI) from water solutions. Methods: The study explored two biosorbents: raw potato peels (RPP) and ATPP. Fourier Transform Infrared (FTIR) spectroscopy was utilized to analyze changes in surface functional groups. Batch biosorption experiments were performed using distinct contact times (30-180min), pH (3–11), and biosorbent dosages (0.1–0.5 g). The Mann-Whitney U test was applied for the statistical analysis. Results and Discussion: The FTIR analysis indicated an enhancement in carboxyl groups on the ATPP surface after acid treatment, with stronger transmittance peak at 1645 cm⁻¹. ATPP showed significant improvements in biosorption capacity compared to RPP, removing 18.23% of 10 mg/L Ni(II) at pH 5 in 120minutes using 0.5 g of ATPP. For Cr(VI), 52.28% removal was achieved at pH 7 with 0.2 g of ATPP within the same time frame. Statistical analysis confirmed the superior performance of ATPP in removing Ni(II) (p = 0.024) and Cr(VI) (p = 0.004). Conclusion: ATPP offers significantly higher biosorption capabilities than RPP attributed to the increased presence of carboxyl groups on the modified surface, indicating potential for eco-friendly effective material in mitigating the heavy metal pollution's health risks.

Efficient Removal of Brilliant Cresyl Blue from Solution Using Inula Racemosa: Experimental Insights, DFT Modeling, and Docking Simulation

AbstractThis study examined the efficacy of Inula Racemosa leaves in the adsorption of Brilliant Cresyl Blue (BCB) from aqueous solutions. The study uses both experimental and theoretical research, including Density Functional Theory (DFT), to gain a better understanding of how the adsorbent and Brilliant Cresyl Blue molecules interact with each other. We determined the point zero value of the charged powder of Inula Racemosa and characterized the functional groups using FTIR spectroscopy. The experimental results indicate a significant ability of our adsorbent to adsorb the cationic dye Brilliant Cresyl Blue, and we have identified optimal conditions for its effective removal. The results suggest that the most effective amount of our biosorbent was 0.1 g. The equilibrium period for biosorption was 10 min, and the biosorbent capacity for biosorption improved with increasing pH. The Pseudo‐second‐order model accurately predicts the retention of Brilliant Cresyl Blue using Inula Racemosa. The Freundlich model was found to be better suitable for analyzing the isotherm data, revealing a maximum adsorption capacity of 3.49 mg g−1, achieving an efficiency removal of 89.95 %. We compared Density Functional Theory (DFT) calculations with experimental observations to validate the theoretical predictions and improve our understanding of the adsorption mechanism. Docking simulations show how the molecules of Inula Racemosa and Brilliant Cresyl Blue interact with each other, including the interactions of hydrogen bonds and electrostatic forces.

Alginate–Bentonite Encapsulation of Extremophillic Bacterial Consortia Enhances Chenopodium quinoa Tolerance to Metal Stress

This study explores the encapsulation in alginate/bentonite beads of two metal(loid)-resistant bacterial consortia (consortium A: Pseudomonas sp. and Bacillus sp.; consortium B: Pseudomonas sp. and Bacillus sp.) from the Atacama Desert (northern Chile) and Antarctica, and their influence on physiological traits of Chenopodium quinoa growing in metal(loid)-contaminated soils. The metal(loid) sorption capacity of the consortia was determined. Bacteria were encapsulated using ionic gelation and were inoculated in soil of C. quinoa. The morphological variables, photosynthetic pigments, and lipid peroxidation in plants were evaluated. Consortium A showed a significantly higher biosorption capacity than consortium B, especially for As and Cu. The highest viability of consortia was achieved with matrices A1 (3% alginate and 2% bentonite) and A3 (3% alginate, 2% bentonite and 2.5% LB medium) at a drying temperature of 25 °C and storage at 4 °C. After 12 months, the highest viability was detected using matrix A1 with a concentration of 106 CFU g−1. Further, a greenhouse experiment using these consortia in C. quinoa plants showed that, 90 days after inoculation, the morphological traits of both consortia improved. Chemical analysis of metal(loid) contents in the leaves indicated that consortium B reduced the absorption of Cu to 32.1 mg kg−1 and that of Mn to 171.9 mg kg−1. Encapsulation resulted in a significant increase in bacterial survival. This highlights the benefits of using encapsulated microbial consortia from extreme environments, stimulating the growth of C. quinoa, especially in soils with metal(loid) levels that can be a serious constraint for plant growth.

Biosorption of heavy metal ions using a wood-rot fungus Schizophyllum commune

In this study, the ability of live mycelia of Schizophyllum commune to remove heavy metals from aqueous solution was investigated. The influence of various experimental parameters, such as pH, temperature, and contact time on the biosorption process was investigated. The maximum biosorption capacity using live biomass was found as 81.5, 90.71, 70.18, and 66.18 mg/g for Pb(II), Sr(II), Zn(II), and Cd(II), respectively, at optimized conditions. The biosorption process reaches equilibrium between 180 and 240 min for the tested metal ions. The experimental data were used to study biosorption isotherm and kinetics models. The thermodynamic parameters, ΔG°, ΔH°, and ΔS°, showed that the biosorption process was endothermic and spontaneous at 303–343 K. SEM images revealed that the presence of metal ions altered the morphology of fungal hyphae. The presence of Pb(II), Sr(II), Zn(II), and Cd(II)on the fungal mycelia was confirmed using SEM-EDX. FTIR spectroscopy of biomass showed the involvement of functional groups like, -CH, amino acid, fatty acid, carboxyl group, and alkane and alkyl groups in adsorption of heavy metal ions. The adsorption capacity of S. commune for removal of heavy metals under the optimized conditions was Sr(II) > Pb(II) > Zn(II) > Cd(II). Thus, the study demonstrated an application of Schizophyllum commune for efficient removal of heavy metals from metal-contaminated water or industrial effluents.

Intensification and characterization of biosorption of microalgal cells on filamentous fungal pellets as effective tools for harvesting of microalgal biomass

Microalgae are promising resources with a variety of advantages and applications. However, their harvesting cost in large-scale cultivation may account for 20–30 % and in some instances up to 50 % of the overall production cost. This study then aimed to apply biosorption of microalgal cells by using fungal pellets as an alternative low-cost and practical harvesting technique. Among the fungal strains screened, Aspergillus tubingensis TSIP9 formed spherical, mycelium packed and consistent in size. The biosorption of microalgal cells process was optimized through response surface methodology (RSM). The maximum harvesting efficiency of 98.3 ± 1.2 % was achieved when using pellet loading of 60 % and pH 5.0. The biosorption process can be explained by Langmuir isotherm model with the maximum biosorption capacity (qmax) of 0.338 g/g and the Langmuir constant (K) of 0.999 L/g. Pseudo-first-order model is suitable for describing the biosorption kinetics of microalgal cells on fungal pellets. The application of fungal pellets in downstream process for microalgae cultivation was attempted. The fungal pellets could harvest microalgal cells as high as 3.70 × 1011 cells/g after 5 cycles of repeated harvesting process. FTIR analysis revealed the possible functional groups involved in fungi-microalgae interaction are CO, CO, CN, and CH. These results indicated that the potential of fungal pellets as effective tools for harvesting/immobilizing microalgal cells and their practical applications in harvesting on a large scale and resource recycling.

Aspergillus versicolor mediated biofabrication of zinc phosphate nanosheets for exploring their antimycotic activity and development of alginate-based nanocomposite for enhanced dye degradation

The production of novel, suitable, and cost-effective nanocomposites are highly required for its prospective application in the remediation of environmental pollutants and as antimycotic agents. Zinc phosphate nanosheets (ZP-ns) were fabricated by harnessing the exometabolites of Aspergillus versicolor and then incorporated within an alginate biopolymer (ZP-ns@Alg) to improve the biosorptive removal of the methyl orange (MthO) dye from its aqueous solution. For the very first time, the antimycotic activity of the green synthesized ZP-ns was unveiled. The mycelial growth inhibition was obtained in a dose-dependent manner with significant (P < 0.05) behavior compared to the control plates. The biosorption conditions using ZP-ns@Alg microbeads were optimized using the response surface methodology-based central composite design (RSM-CCD) to maximize the biosorption efficiency. The highest biosorptive efficiency was achieved at pH 4.0, biosorption dosage 0.07 g, contact time 50 min, dye concentration 100 mg/l, and shaking speed 100 rpm. The equilibrium data were more tailored to the pseudo-second order (PS) model with an R2 of 0.9955 and a Langmuir isotherm (R2 = 0.9945) with a maximum biosorptive capacity (qmax) of 166.95 mg/g and an average RL value of 0.0003, indicating favorable biosorption. The removal capacity was reduced to ∼90 % after the 6th cycle, which is a robust signal that the developed biosorbent microbeads could be recycled and regenerated for a prolonged time. These results marked the application of ZP-ns as a novel antimycotic agent with excellent activities. Microbeads, made from low-cost biopolymers, can be applied to remediating environmental pollutants from wastewater.

Revisiting biochemical pathways for lead and cadmium tolerance by domain bacteria, eukarya, and their joint action in bioremediation.

With the advent rise is in urbanization and industrialization, heavy metals (HMs) such as lead (Pb) and cadmium (Cd) contamination have increased considerably. It is among the most recalcitrant pollutants majorly affecting the biotic and abiotic components of the ecosystem like human well-being, animals, soil health, crop productivity, and diversity of prokaryotes (bacteria) and eukaryotes (plants, fungi, and algae). At higher concentrations, these metals are toxic for their growth and pose a significant environmental threat, necessitating innovative and sustainable remediation strategies. Bacteria exhibit diverse mechanisms to cope with HM exposure, including biosorption, chelation, and efflux mechanism, while fungi contribute through mycorrhizal associations and hyphal networks. Algae, especially microalgae, demonstrate effective biosorption and bioaccumulation capacities. Plants, as phytoremediators, hyperaccumulate metals, providing a nature-based approach for soil reclamation. Integration of these biological agents in combination presents opportunities for enhanced remediation efficiency. This comprehensive review aims to provide insights into joint action of prokaryotic and eukaryotic interactions in the management of HM stress in the environment.

Green integrative large scale treatment of tannery effluent, CO2 sequestration, and biofuel production using oleaginous green microalga Nannochloropsis oculata TSD05: An ecotechnological approach

In this present investigation, the freshwater microalga Nannochloropsis oculata TSD05 was used to demonstrate multiforius environmental applications viz., bioremediation of tannery effluent, carbon sequestration, and green renewable biodiesel production from treated microalgal biomass. The microalga Nannochloropsis oculata TSD05 was exhibited unique heavy metal reduction capabilities and reduced significant amount of heavy metals viz., 96.62% of copper (Cu2+), 99.9% of chromium (Cr3+), 98.36% of zinc (Zn2+), 98.71% of cadmium (Cd2+), 97.96% of lead (Pb2+), 98.88% of Cobalt (Co2+), and 98.76% of nickel (Ni2+). The biosorption capacity rate (qmax) of heavy metals reduction and highest R2 of 97.84% exhibited at 12 days of effluent treatment by Langmuir and Freundlich isotherm models. The phytotoxicity analysis was tested againt treated tannery effluent using Vigna radiate, Sapindus muukorossi seeds and 98.45%, 99.05% seeds were germinated. The Nannochloropsis oculata TSD05 microalga was utilized 98.45% of CO2 by biofixation kinetics, 372 mg g−1 of lipid, 3.65 mg mL−1 of biomass and 4.64 mLg−1 of biodiesel were produced. The produced biodiesel was confirmed and identification of 18 fatty acid methyl ester (biodiesel) compounds using GCMS. The recognition of 17 functional groups was identified using FTIR analysis and the microalga Nannochloropsis oculata TSD05 potential for sustainable and renewable green energy production. The potential future application of Nannochloropsis oculata TSD05 is to increase lipid production and biodiesel yield. Scaling up the bioremediation process can also validate these microalga's feasibility for use in wastewater treament. Enhancing heavy metal biosorption and carbon sequestration efficiency through genetic engineering could also maximize environmental benefits.

Performance assessment and characterization of the biosorption of the azo dye reactive Red 2 on thermally inactivated biomass of Trichoderma reesei

The present study evaluated and characterized the performance in the biosorption of the dye azo Reactive Red 2 (RR2) on thermally sterilized biomass of the fungus Trichoderma reesei. An FTIR analysis of unloaded and loaded biomass with RR2 confirmed the interactions between dye molecules and functional groups on the fungal biomass surface. The decrease in the initial pH of 9 to 3 with an increase in the temperature of 20 to 40 °C improved the biosorption, reaching for RR2 a higher removal efficiency of 76.88% at pH 3 and 40 °C. A pseudo-second-order model explained the biosorption kinetics of RR2 (R2≥0.9869), and the intraparticle diffusion model showed that the biosorption process was initially controlled by diffusion rate and later by biomass surface saturation with the dye molecules. The Langmuir isotherm explained the biosorption equilibrium well (R2 ≥ 0.9241), achieving the maximum biomass biosorption capacity (qmax ) value at 61.72 mg g−1. The dimensionless separation factor values (0.0632 ≤ RL ≤ 0.0973) and the thermodynamic evaluation of the process (ΔG° ≤ −24.09 kJ mol−1, ΔH° ≥ 12.39 kJ mol−1, ΔS° ≥ 0.1265 kJ mol−1 K−1) demonstrate that the biosorption was favorable, reversible, spontaneous, and endothermic. The findings in the present study allow it to consider the biomass of Trichoderma reesei thermally sterilized as a biosorbent biomaterial that can be used for bioprocess design in removing the azo reactive dyes from textile wastewater.

Effective application of green nano adsorbent on the removal of carbofuran from wastewater

In this study, carbofuran (CF) was eliminated from wastewater using pomegranate peel nano adsorbent (PPNA). Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) before and after adsorption were used to assess the process efficiency. BET demonstrated that the PPNA has a specific surface area of 356.5 m2/g. The PPNA was tested under some environmental factors, such as contact time, concentration, adsorbent dose, temperature, and pH. Experimental work was done within the range of 10–50 mg/l initial concentration and the best biosorption capacities were found at 30 min contact time, 0.7 g adsorbent dose, 25 °C, and pH 2. The Freundlich isotherm was the best-fitting isotherm model. The pseudo-second-order model provided the best fit to the process kinetics and indicated that the intra-particle diffusion stage is the rate-limiting step for the process. The study of thermodynamics showed that carbofuran adsorption on PPNA was physisorption (ΔG = −3.2334 kJ/mol) and spontaneous at high temperatures (ΔH = 22.2058 kJ/mol, ΔS = 85.0355 J/mol K). Design of a single-stage batch adsorber for the adsorption of CF from aqueous liquors using PPNA was also done.

Nymphaea alba leaf powder effectiveness in removing nisin from fermentation broth using docking and experimental analysis

The accumulation of nisin in the fermentation medium can reduce the process's productivity. This research studied the potential of Nymphaea alba leaf powder (NALP) as a hydrophobic biosorbent for efficient in-situ nisin adsorption from the fermentation medium by docking and experimental analysis. Molecular docking analysis showed that di-galloyl ellagic acid, a phytochemical compound found in N. alba, had the highest affinity towards nisin. Enhancements in nisin adsorption were seen following pre-treatment of NAPL with HCl and MgCl2. A logistic growth model was employed to evaluate the growth dynamics of the biosorption capacity, offering valuable insights for process scalability. Furthermore, optimization through Response Surface Methodology elucidated optimal nisin desorption conditions by Liebig's law of the minimum, which posits that the scarcest resource governs production efficiency. Fourier Transform Infrared (FTIR) spectroscopy pinpointed vital functional groups involved in biosorption. Scanning electron microscopy revealed the changing physical characteristics of the biosorbent after exposure to nisin. The findings designate NALP as a feasible adsorbent for nisin removal from the fermentation broth, thus facilitating its application in the purification of other biotechnological products based on growth and production optimization principles.

Cu(II) Biosorption and Synthesis of CuO Nanoparticles by Staphylococcus epidermidis CECT 4183: Evaluation of the Biocidal Effect

Copper contamination of natural waters is a global problem that affects ecosystems and public health, yet this metal is an essential micronutrient and has important applications. The efficacy of Staphylococcus epidermidis CECT 4183 as a Cu(II) biosorbent in synthetic solutions and its potential ability to synthesize CuO nanoparticles (CuO-NPs) from its cellular extract was investigated. In addition, the biocidal potential of the nanoparticles was evaluated against five microorganisms. Using response surface methodology, the optimal operating conditions were determined to be biomass dose, 0.2 g/L, and pH 5.5. Equilibrium tests were performed, and biosorption isotherms were obtained for four models with a maximum biosorption capacity of 48.14 mg/g for the Langmuir model. Different spectroscopic and microscopic techniques were used to determine the mechanisms involved in the biosorption process, which was dominated by surface physicochemical interactions with strong involvement of methyl, methylene, carbonyl, amino, and phosphate groups. The techniques also allowed for characterizing the obtained nanoparticles, which had a quasi-spherical morphology and an average size of 14 nm. Finally, biocidal tests showed that the CuO-NPs had a good inhibitory capacity for the microorganisms tested, with minimum inhibitory concentrations (MIC) between 62.5 and 500 µg/mL for bacteria and between 1000 and 2000 µg/mL for yeasts. S. epidermidis CECT 4183 showed good potential for Cu(II) bioremediation and for the synthesis of CuO-NPs with biocidal capacity. S. epidermidis CECT 4183 showed good potential for use in Cu(II) biosorption, and its cell extract presented a high capacity for the green synthesis of CuO-NPs, which at the same time turned out to be good biocidal agents.

Optimization and mechanism studies for the biosorption of rare earth ions by Yarrowia lipolytica.

Research on the recovery of rare earth elements from wastewater has attracted increasing attention. Compared with other methods, biosorption is a simple, efficient, and environmentally friendly method for rare earth wastewater treatment, which has greater prospects for development. The objective of this study was to investigate the biosorption behavior and mechanism of Yarrowia lipolytica for five rare earth ions (La3⁺, Nd3⁺, Er3⁺, Y3⁺, and Sm3⁺) with a particular focus on biosorption behavior, biosorption kinetics, and biosorption isotherm. It was demonstrated that the biosorption capacity of Y. lipolytica at optimal conditions was 76.80mg/g. It was discovered that the biosorption process complied with the pseudo-second-order kinetic model and the Langmuir biosorption isotherm, indicating that Y. lipolytica employed a monolayer chemical biosorption process to biosorb rare earth ions. Characterization analysis demonstrated that the primary functional groups involved in rare earth ion biosorption were amino, carboxyl, and hydroxyl groups. The cooperative biosorption of rare earth ions by Y. lipolytica was facilitated by means of surface complexation, ion exchange, and electrostatic interactions. These findings suggest that Y. lipolytica has the potential to be an effective biosorbent for the removal of rare earth elements from wastewater.

Sorption of chromium from aqueous solutions using Fucus vesiculosus algae biosorbent

The presence of heavy metals in wastewater is an environmental concern and the current treatment procedures are very expensive so it is necessary to find effective and inexpensive biosorbents. In this study, Fucus vesiculosus was used as a biosorbent for the biosorption of Cr(III) ions from the aqueous solutions. Biosorption parameters, such as pH, adsorbent dose, contact time, and initial concentrations of Cr(III) had the most impact on the sorption process. The required pH value for sorption was 5, the biosorbent dose was 4.0 g/L, the contact time was seen to occur after 90 min, and the Cr(III) removal decreased from 98.9 to 92%. The maximum biosorption capacity of chromium was 14.12 mg/g. FTIR analysis of Fucus vesiculosus biomass before the sorption process contains carboxyl, amino, hydroxyl, alkyne, and carbonyl groups, and according to the analysis after the sorption process, it was found that Cr(III) metal ions were incorporated within the sorbent during the interaction with (=C–H) active functional groups. The biosorption data were found to be perfectly suited by Langmuir equilibrium isotherm model. According to the results of this study, Fucus vesiculosus is an effective biosorbent for the removal of Cr(III) from aqueous solutions.

A critical review on hydrothermal liquefaction screening using Microalgae as a two-way approach to sewage water treatment and biofuel production

&lt;p&gt;Hydrothermal liquefaction (HTL) is involved in concurrently treating both sewage water and generating biofuels. It involves the analysis of various operating parameters, such as pressure, catalyst temperature, and reaction time, to determine the productivity and physiochemical properties of the resulting bio-oil. The critical assessment of over 100 algal strains, compared on the basis of their growth kinetics in different wastewater environments and their HTL-based yields, identified Auxenochlorella pyrenoidosa and Microchaete spirulina strains as the most suitable ones for optimised municipal wastewater treatment. Additionally, other strains like Chlorella sorokiniana, Tetradesmus obliquus, and Desmodesmus abundance are found to be effective for heavy metal remediation in municipal wastewater due to their high biosorption capacities. Furthermore, certain microalgal strains, namely Auxenochlorella pyrenoidosa, Botryococcus braunii, Microchloropsis gaditana, and Microchaete spirulina, were described as promising microalgae in the production of high crude oil yields through the HTL technique. The current review highlights the integrated approach of sustainable and economical HTL techniques using the best microalgal strains as a technologically and environmentally feasible solution selected through a systematic protocol for sewage water treatment and biofuel production.&lt;/p&gt;

Water Hyacinth Leaves Are an Efficient, Green, and Cost-Effective Biosorbent for the Removal of Metanil Yellow from Aqueous Solution: Kinetics, Isotherm, and Thermodynamic Studies.

Excessive water hyacinth growth in aquatic environments and metanil yellow (MY) dye in industrial wastewater pose severe environmental and public health challenges. Therefore, this study evaluated the effects of various process factors on batch MY biosorption onto water hyacinth leaves (LECs) and MY biosorption kinetics, equilibrium, and thermodynamics. The optimal pH for MY biosorption by LECs was 1.5-2.0. The initial MY concentration affected the equilibrium MY biosorption capacity but not the LEC particle size and solution temperature. However, the LEC particle size and solution temperature affected the MY biosorption rate; the biosorption rate was higher at a lower particle size (0.15-0.3 mm) and a higher temperature (62 °C) than at higher particle sizes and lower temperatures. The pseudo-second-order model adequately described the biosorption kinetics of MY by LECs at the different levels of the process factors, whereas the Sips and Redlich-Peterson models satisfactorily represented the biosorption isotherm of MY. The Sips model predicted a maximum MY biosorption capacity of 170.8 mg g-1. The biosorption of MY by LECs was endothermic and not spontaneous. These findings demonstrate that LECs exhibit great potential for bioremediating MY-contaminated wastewater, thereby providing valuable insights for effective water treatment and pollution control strategies.