Biomass Dosage Research Articles

Efficient and sustainable approach of heavy metal adsorption from wastewater using algal biomass of Hypnea valentiae (Turner) Montagne, 1841

The biosorption of heavy metals especially, Cd2+, Pb2+, and Zn2+ from wastewater were evaluated using the biomass of macroalgae, Hypnea valentiae found in coastal waters of Rameshwaram, Tamil Nadu, India. The probable functional groups involved in the biosorption process was analyzed by Fourier transform infrared spectroscopy. The specific surface area, pore volume and pore diameter of prepared biosorbent was determined by Brunauer–Emmett–Teller (BET) analysis and it was found to be 59.993 m2 g−1, 0.292 cc g−1 and 1.429 nm, respectively. The scanning electron microscopy images after the biosorption revealed that the heavy metals have been adsorbed on to the surface of biosorbent. The optimization study was performed using Box–Behnken design and the optimum parameters used were initial concentration of metal ions (10–500 mg L−1), biomass dose (5–25 g L−1), contact time (10–120 min), temperature (25–45 °C), agitation speed (60–120 rpm) and pH (2–14). The heavy metal uptake (biosorption) was assessed by isotherm models including Dubinin–Radushkevich (D–R), Freundlich and Langmuir models. The maximum sorption of metal ions was observed in Langmuir isotherm model (R L 0.1773 and K F 2.2030 L mg−1) with an R 2 value close to 0.99 clearly indicating the chemical mode of metal ion adsorption. Also, the sorption of Cd2+, Pb2+, and Zn2+ on to the surface of algal biomass followed pseudo-second-order kinetics with a rate constant, k2 being 9.627 × 10−3 g (mg min) −1 and qe being 93.98496 mg g−1, strongly supporting the chemisorption mechanism. The computed thermodynamic parameters (ΔG°, ΔH, and ΔS) demonstrated an endothermic, spontaneous biosorption that was feasible. The maximum removal efficiency was achieved for Pb (92.86%) followed by Cd (91.48%) and Zn (87.32%). The biosorbent can be reused and regenerated up to four cycles efficiently. There was a significant reduction in the biological oxygen demand, chemical oxygen demand, total dissolved solids, and pH of wastewater after treatment with the biosorbent. From this study, it is assessed that the biomass from red algae can be utilized for the biosorption of heavy metals from polluted water which is cost-effective and eco-friendly.

Biosorption of Pb2+, Cd2+ and Zn2+ from aqueous solutions by Agrobacterium tumefaciens S12 isolated from acid mine drainage

Heavy metal pollution is a global environmental issue, and microorganisms play a crucial role in the bioremediation of heavy metal-contaminated wastewater. The study isolated heavy metal-resistant bacterium and observed their absorption ability toward Pb2+, Cd2+ and Zn2+. We isolated Agrobacterium tumefaciens S12 from acid mine drainage. The various factors influencing its adsorption performance, including pH, biomass dosage, initial metal ion concentration, and adsorption temperature, were investigated in detail. Chemisorption controls the adsorption rate due to the results better fitted by pseudo-second order kinetics. The maximum adsorption capacities of Pb2+, Cd2+ and Zn2+ on A. tumefaciens S12 were 234, 58 and 51 mg g−1 at 30 °C from Langmuir isotherm, respectively. The adsorption processes for the three heavy metal ions were spontaneous and exothermic in nature. In bimetallic systems, biosorption of Pb2+ ions was preferential to that of Cd2+ and Zn2+. Furthermore, scanning electron microscopy coupled to energy dispersive spectroscopy, Fourier-transform infrared spectra and X-ray photoelectron spectroscopy analysis demonstrated that the adsorption mechanisms include ion-exchange, complexation interaction between the heavy metal ions and the functional groups on the surface of biomass. The obtained results indicated that A. tumefaciens S12 can be applied as an efficient biosorbent in bioremediation technology to sequestrate heavy metal ions from aqueous solution.

Biosorption of thorium onto Chlorella Vulgaris microalgae in aqueous media

Thorium biosorption by a green microalga, Chlorella Vulgaris, was studied in a stirred batch reactor to investigate the effect of initial solution pH, metal ion concentration, biomass dosage, contact time, kinetics, equilibrium and thermodynamics of uptake. The green microalgae showed the highest Th adsorption capacity at 45 °C for the solution with a thorium concentration of 350 mg L−1 and initial pH of 4. The amount of uptake raised from 84 to 104 mg g−1 as the temperature increased from 15 to 45 °C for an initial metal concentration of 75 mg L−1 at pH 4. Transformation Infrared Spectroscopy (FTIR) was employed to characterize the vibrational frequency changes for peaks related to surface functional groups. Also, the scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to determine the morphological changes and elemental analysis of the biosorbent before and after the sorption process. The Langmuir isotherm was in perfect agreement with the equilibrium empirical data of thorium biosorption and the highest sorption capacity of the Chlorella Vulgaris microalgae was determined as 185.19 mg g−1. Also, the results of kinetic studies show that the thorium biosorption process follows a pseudo-second-order kinetic model. The negative value of ΔG0 indicates spontaneity and the positive values of ΔH0 indicate the endothermic nature of the adsorption process.

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.

Biosorption of Cu+ 2 by Green Algae, Ulva fasciata: Optimization by Response Surface Methodology

AbstractU. fasciata biomass, a green algae was used as adsorbent, investigated and optimized the environmental parameters using central factorial design for the Cu+ 2 removal. Biosorption of Cu+ 2 involves the functional groups –CO, –OH, and N–H of U. fasciata biomass. Various parameters were estimated using Response Surface Methodology (RSM), including pH (4–6), initial Cu+ 2 concentration (60–140 mg L− 1), biomass dosage (0.08–0.40 g L− 1) and temperature (20–40 °C). It was found that the uptake of Cu+ 2 by U. fasciata was 62.31 mg L− 1 at an initial concentration of 80 mg L− 1, a temperature of 35 °C, and a pH of 5.245. In order to analyze the equilibrium data, applied Langmuir, Freundlich, Langmuir-Friendly (L-R), and Redlich-Peterson (L-R) isotherm models. The multiple mechanisms were involved in the removal of Cu+ 2 including chelation, ion-exchange and adsorption on UF biomass. It is believed that the U. fasciata biomass is a suitable material for the removal of Cu+ 2 ions from wastewaters.

A statistical optimization for almost-complete methylene blue biosorption by Gracilariabursa-pastoris

In this study, the dried biomass of four marine algae, namely Porphyra sp., Gracilaria bursa-pastoris, Undaria pinnatifida and Laminaria sp., were screened for their ability to remove methylene blue (MB) dye from aqueous solutions. Statistical approaches of the Plackett-Burman Design (PBD) and Box-Behnken Design (BBD) were applied to optimize different environmental conditions in order to achieve the maximum MB removal percentage by Gracilaria bursa-pastoris. The biosorbent was characterized before and after adsorption process using FTIR, XRD and SEM analysis. Additionally, isotherms, kinetics and thermodynamics studies were conducted to investigate the adsorption behavior of the adsorbent. The results showed that Gracilaria bursa-pastoris achieved the highest dye removal efficiency (98.5 %) compared to 96.5 %, 93.5 % and 93.9 % for Undaria pinnatifida, Porphyra sp. and Laminaria sp., respectively. PBD analysis revealed that the agitation speed, pH, and biomass dose were found to be the significant parameters affecting MB removal onto Gracilaria dried biomass. According to the BBD results, the maximum dye removal percentage (99.68 %) was obtained at agitation speed of 132 rpm, pH 7 and biomass dose of 7.5 g/L. FTIR, XRD and SEM analysis demonstrated the participation of several functional groups in the adsorption process and changes in the cell surface morphology of the adsorbent following the dye adsorption. The adsorption isotherms showed better fit to Freundlich model (R2 = 0.9891) than the Langmuir, Temkin, and Dubinin-Radushkevich models. The adsorption kinetics were best described by the pseudo-second-order model (R2 = 0.9999), suggesting the chemical interactions between dye ions and the algal biomass. The thermodynamic parameters indicated that the adsorption of MB onto Gracilaria dried biomass was spontaneous, feasible, endothermic and random. These results indicate that dried biomass of Gracilaria bursa-pastoris is an attractive, environmentally friendly, cheap and effective agent for MB dye removal from environmental discharges.

Evaluation of resistance patterns and bioremoval efficiency of hydrocarbons and heavy metals by the mycobiome of petroleum refining wastewater in Jazan with assessment of molecular typing and cytotoxicity of Scedosporium apiospermum JAZ-20

Jazan Industrial Economic City (JIEC) is located on the Red Sea coast in the province of Jazan, southwest of Saudi Arabia anchors diverse heavy and secondary industries in the energy, water desalination, petroleum, aluminum, copper, refineries, pharmaceuticals and food manufacturing fields. These various industries generate a large quantity of industrial wastewaters containing various toxicants. The present work represents ecologically beneficial alternatives for the advancement of environmental biotechnology, which could help mitigate the adverse impacts of environmental pollution resulting from petroleum refining effluents. The mycobiome (32 fungal strains) isolated from the industrial wastewater of the refinery sector in Jazan were belonged to five fungal genera including Fusarium, Verticillium, Purpureocillium, Clavispora and Scedosporium with a distribution percentage of 31.25, 21.88, 15.63, 12.50 and 18.75 %, respectively.These isolates showed multimetals tolerance and bioremoval efficiency against a large number of heavy metals (Fe2+, Ni2+, Cr6+, Zn2+, As3+, Cu2+, Cd2+, Pb2+, Ag+ and Hg2+) along with potent bioremediation activity toward crude oil and the polycyclic aromatic hydrocarbons. Interestingly, the mycobiome resistance patterns obtained against different classes of fungal antibiotics including azole (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole and ketoconazole), echinocandin (anidulafungin, caspofungin and micafungin) and polyene (amphotericin B) drugs proved the prevalence of antibiotic resistance among the mycobiome of refinery industry in Saudi Arabia is relatively low. The fungal isolate under isolation code JAZ-20 showed the highest bioremoval efficiency against heavy metals (90.8–100.0 %), crude oil (89.50 %), naphthalene (96.7 %), phenanthrene (92.52 %), fluoranthene (100.0 %), anthracene (90.34 %), pyrene (85.60 %) and chrysene (83.4 %). It showed the highest bioremoval capacity ranging from 85.72 % to 100.0 % against numerous pollutants found in a wide array of industrial effluents, including diclofenac, ibuprofen, carbamazepine, acetaminophen, sulfamethoxazole, bisphenol, bleomycin, vincristine, dicofol, methyl parathion, atrazine, diuron, dieldrin, chlorpyrifos, profenofos and phenanthrene. The isolate JAZ-20 was chosen for molecular typing, cytotoxicity assessment, analysis of volatile compounds and optimization investigations. Based on phenotypic, biochemical and phylogenetic analysis, strain JAZ-20 identified as Scedosporium apiospermum JAZ-20. This strain is newly discovered in industrial effluents in Saudi Arabia. Fungal strain JAZ-20 consistently produced various types of saturated and unsaturated fatty acids. the main fatty acids were C14:0 (1.95 %), iso-C14:0 (2.98 %), anteiso-C14:0 (2.13 %), iso-C15:0 (9.16 %), anteiso-C15:0 (11.75 %), C15:0 (7.42 %), C15:1 (2.37 %), anteiso-C16:0 (3.4 %), C16:0 (10.3 %), iso-C16:0 (9.5 %), C17:1 (1.36 %), anteiso-C17:1 (8.64 %), iso-C18:0 (11.0 %), C18:0 (3.63 %), anteiso-C19:0 (3.78 %), anteiso-C20:0 (2.0 %), iso-C21:0 (2.44 %), C23:0 (1.15 %), and C24:0 (2.17 %). These fatty acids serve as natural and eco-friendly antifungal agents, promoting fungal resistance and inhibiting the production of mycotoxins in the environment. Despite being an environmental isolate, its cytotoxicity was assessed against both normal and cancerous human cell lines. The IC50 values of JAZ-20 extract were 8.92, 10.41, 20.0, 16.5, and 40.0 μg/mL against WI38, MRC5, MCF10A, HEK293 and HDFs normal cells and 43.26, 33.75, and 40.0 μg/mL against liver (HepG2), breast (A549) and cervix (HeLa) cancers, respectively. Based on gas chromatography-mass spectrometry (GC-MS), analysis the extract of S. apiospermum JAZ-20 showed 47 known volatile compounds (VOCs) for varied and significant biological activities. Enhancing the bioremoval efficiency of heavy metals from actual refining wastewater involves optimizing process parameters. The parameters optimized were the contact time, the fungal biomass dosage, pH, temperature and agitation rate.

Phycoremediation of Phenolphytalein, Indigo Carmine, Methyl Orange and Eriochrome Black T By Using Chlamydomonas and Chlorella sp. (Chlorophyta)

This work aimed to evaluate the decolorization of phenolphthalein (PP), indigo carmine (IC), methyl orange (MO) and eriochrome black T (EBT) by using Chlorella and Chlamydomonas as a biosorbent. This experiment used the batch adsorption method to study the adsorption effect of pH, biomass dosage, contact time, initial dye concentration and temperature on the dyes. The adsorption of the dyes onto the cells were fitted with the Langmuir and Freundlich isotherms. The results showed that the optimum conditions for PP removal (99%) was obtained at pH 4, contact time of 120min, 35°C, algal dosage of 0.5 mg/mL and dye concentration of 100 mg/L on to the cells. The sample prepared at 25°C, 120 min, 1 mg/mL algal dosage, 25 mg/L dye concentration and at pH 4 had the best adsorption effect on IC on to the both of cells (99-98%). In addition, the optimum conditions for MO and EBT removal (99-97%) was obtained at pH 2-4, contact time of 30 min, 25°C, algal dosage of 0.5mg/mL and dye concentration of 100mg/L. The results of this study reveal that the algae cells can be utilized as an efficient and eco-friendly biosorbent for the removal of the indicator dyes from aqueous solution.

EVALUATION OF THE BIOSORPTION OF Mn²⁺ AND Zn²⁺ BY PASSION FRUIT PEEL: STUDY OF DOSAGE AND CONTACT TIME

Objective: The objective of this study is to investigate he effectiveness of Mn2+ and Zn2+ biosorption by passion fruit peel as a sustainable and economically viable alternative to the biosorption process. Method: The methodology adopted for this research comprises the characterization of the biomass and batch tests. Tests were carried out with different masses of biomass in standard solutions of the metals investigated. The biosorption capacity of the biomass and the removal efficiency were calculated based on the differences in concentration of the metal ions. Results and Discussion: The results obtained revealed that the biomass showed high efficiency (close to 100%) for both cations. The contact time of 30 minutes was sufficient to reach equilibrium in the biosorption capacity of the metals, indicating the speed and effectiveness of the process. Research Implications: The practical and theoretical implications of this research provide valuable information on the application of passion fruit peel as a biosorbent in the removal of potentially toxic metals from contaminated wastewater. These results may influence practices in the field of environmental remediation and environmental engineering, as well as in agro-industrial waste management. Originality/Value: This study contributes to the literature by highlighting the originality of using passion fruit peel in natura as a biosorbent, presenting an innovative and sustainable approach to the remediation of contaminated effluents. The high efficiency of ion removal with low biomass dosages and short contact times adds knowledge to the field of biosorption using agro-industrial waste.

Removal of cadmium ions from aqueous solution by raw, pretreated, and immobilized Pterocladia capillacea biomass

The adsorption of Cd (II) by Pterocladia capillacea in a batch system is the topic of the current investigation. Different pH (3–8) and starting Cd (II) concentrations were examined to determine the biosorption effectiveness for Cd (II) removal (20-100 ppm), period (5–120 min), agitation rate (50–250 rpm), and dose of biomass (0.01–0.1 g/50 ml of metal solution). At ideal conditions, the highest capability for bioadsorption was 8.407 mg g−1 dwt. The highest adsorption efficiency (96.047%) was attained by pretreating algal biomass using an autoclave. According to the findings, utilizing 0.1 g of alga produced the maximum removal efficiency compared to a control. Fourier transform infrared analysis of raw and processed algal biomass showed that hydroxyl, amide with hydrogen link, and carbonyl stretching before and during cadmium biosorption, carboxyl groups significantly contributed to biosorption. According to the findings, Pterocladia capillacea is an effective bioagent for removing cadmium from aqueous solutions.

Optimization of Pb (II) Ion Removal from Synthetic Wastewater Using Dead (Chlorophyta) Macroalgae: Prediction by RSM Method

The Pb2+ ions biosorption removal onto dead biomass of Chlorophyta algae is optimized by employing response surface methodology (RSM). Central composite design (CCD)-based experiments were carried out, and RSM was used to evaluate the results. The effects of contact time (15-120min), with pH solution (2-7), initial lead concentration (25-100 mg/L), biomass dose (0.01-1 g/100 mL), agitation speed (100-300 rpm) on the biosorption process were investigated. The optimal conditions of the experimental, data were pH (5), metal concentration (50mg/L), dosage (0.2g/100mL), agitation speed (200 rpm), and contact time of 120 min with constant particle size (63 mm), which gave 98.88% removal efficiency. All the variables and reactions in the biosorption experiments were evaluated using the desirability function to determine the optimal point at which the desired parameters may be attained. The promising results obtained indicate the potential use of Chlorphyta green macroalgae to treat industrial wastewater polluted with toxic metals.

Chloride ion sequestration by vetiver root biosorption: isotherm, kinetic, and thermodynamic analyses and ANN prediction

ABSTRACT The present research investigates the potential of activated vetiver root powder as a bioadsorbent for removing chloride ions from saline aqueous environments, especially relevant for addressing agricultural water scarcity. Factors such as pH, biomass dosage, contact duration, and initial salt ion concentration were examined. Thermodynamic analysis provided insights into the adsorption process, demonstrating the feasibility, non-spontaneous behavior, and exothermic nature of chloride ion adsorption onto activated vetiver root powder. The batch adsorption of chlorides adhered to the Langmuir equation and a pseudo-second-order kinetic model, demonstrating a monolayer adsorption capacity of 17.58 mg/g for activated vetiver powder. An artificial neural network (ANN) was used to develop a predictive model for estimating the percentage removal of chloride ions. The values of R2 and mean squared error were used to determine the predictive performance of the ANN. In the near term, prospective commercial uses of activated vetiver powder merit further investigation through in-depth research using real wastewater containing salinity-inducing ion.

Ecofriendly Application of Calabrese Broccoli Stalk Waste as a Biosorbent for the Removal of Pb(II) Ions from Aqueous Media

A new biosorbent obtained from Calabrese broccoli stalks has been prepared, characterised and used as an effective, low-cost and ecofriendly biomass to remove Pb(II) from aqueous solutions, without any complicated pretreatment. Structural and morphological characterisation were performed by TGA/DGT, FTIR and SEM/EDX; the main components are hemicellulose, starches, pectin, cellulose, lignin and phytochemicals, with important electron donor elements (such as S from glucosinolates of broccoli) involved in Pb(II) sorption. The biosorbent showed values of 0.52 and 0.65 g mL−1 for bulk and apparent densities, 20.6% porosity, a specific surface area of 15.3 m2 g−1, pHpzc 6.25, iodine capacity of 619 mg g−1 and a cation exchange capacity of 30.7 cmol kg−1. Very good sorption (88.3 ± 0.8%) occurred at pH 4.8 with a biomass dose of 10 g L−1 after 8 h. The Freundlich and Dubinin–Radushkevich isotherms and the pseudo-second-order kinetic models explained with good fits the favourable Pb(II) sorption on the heterogeneous surface of broccoli biomass. The maximum adsorption capacity was 586.7 mg g−1. The thermodynamic parameters evaluated showed the endothermic and spontaneous nature of the Pb(II) biosorption. The chemical mechanisms mainly involved complexation, ligand exchange and cation–π interaction, with possible precipitation.

Performance optimization for Pb(II) -containing wastewater treatment in constructed wetland-microbial fuel cell triggered by biomass dosage and Pb(II) level.

Three identical sets of constructed wetland-microbial fuel cells (CW-MFCs) fabricated with biomass carbon source addition were constructed and underwent the short- and long-term experiments. For this, the efficacy of biomass dosage and Pb(II) concentration towards Pb(II) removal and concurrent bioelectricity production of CW-MFCs were systematically explored. From the perspective of integrated capabilities and economic benefits, the solid biomass carbon sources equivalent to 500mg/L COD was regarded as the optimal dosage, and the corresponding device was labeled as CW-MFC-2. For the short-term experiment, the closed-circuit CW-MFC-2 produced maximum output voltages and power densities in a range of 386-657mV and 1.55 × 103-6.31 × 103 mW/m2 with the increasing Pb(II) level, respectively. Also, Pb(II) removal up to 94.4-99.6% was obtained in CW-MFC-2. With respect to long-term experiment, Pb(II) removal, the maximum output voltage, and power density of CW-MFC-2 ranged from 98.7 to 99.2%, 322 to 387mV, and 3.28 × 102 to 2.26 × 103 mW/m2 upon 200mg/L Pb(II) level, respectively. The migration results confirmed the potential of substrate and biomass for Pb(II) adsorption and fixation. For the cathode, Pb(II) was fixed and removed via binding to O. This study enlarges our knowledge of effective modulation of CW-MFCs for the treatment of high-level Pb(II)-containing wastewater and bioelectricity generation via adopting desirable biomass dosage.

The effect of different doses of dry biomass of chlorella vulgaris microalgae on the dairy productivity of Zaanen goats

Dairy goat breeding is a new developing branch of animal husbandry in Russia. The prospects for processing goat’s milk are very wide, which is due to an increase in consumer demand for it. Obtaining the maximum amount of products and maintaining animal health is possible with the use of modern feed products. Therefore, an important and urgent task of scientific research is to study the productivity of dairy goats when feeding dry biomass of microalgae Chlorella Vulgaris, which was the purpose of this work. The objects of the study were dairy goats in the type of Zaanen breed. To conduct an experiment based on the principle of groups of analogues, taking into account live weight and age, four groups of female goats (three experimental and one control) of 20 animals each (according to the Ovsyannikov method) were formed. The animals of the control group received the basic household ration, and dry biomass of Chlorella Vulgaris microalgae was introduced into the diet of the experimental groups in doses of 4; 6; 8 g / kg of body weight / day. As a result of the experiment, it was found that the introduction of an experimental drug into the diet of goats increased the average daily milk yield of goats of the first experimental group by 0.02%, the second experimental group by 1.66 and the third experimental group by 3.27%, which allows us to determine the most optimal dose of the introduction of an experimental probiotic drug into the diet of goats, which amounted to 6 g / kg of body weight.

Механизм биосорбции металлов из электронных отходов микроскопическими водорослями

The development of technologies for extracting metals from waste is an urgent task. In this study, a poorly studied technology for the extraction of metals from electronic waste by microscopic algae, based on the biosorption method, was considered. The efficiency of the technology is determined both by the parameters of the biosorption process (properties and dose of biomass, temperature, pH, contact time of the adsorbate with the biosorbent), and the chemical composition of the solution obtained during the leaching of prepared electronic waste and containing metals. In the course of the study, the presence of functional groups in the biosorbent that could enter into chemical interaction with the recovered metals, the chemical properties of metals in the test solution were identified, and the leaching of the sorbed metals from the biosorbent was assessed. Microscopic algae of the species Chlorella sorokiniana, Chlorella vulgaris, Chlorella spirulina, and the genus Scenedesmus sp. were used as a biosorbent. The metal was sourced from mobile phone/smartphone screens and computer monitors. Analysis of the component composition of screens and monitors showed that it is represented by more than 10 different metals belonging to the group of basic metals and 7 metals belonging to the group of rare earth, rare and precious metals. Using the method of IR spectroscopy, the presence of the following functional groups in the cell walls and organoids of microscopic algae was proved: amino groups, hydroxyl and carboxyl groups. The results of experimental studies have established a mixed mechanism of biosorption, including physical sorption and chemisorption. As evidence, we used data on the partial leaching of sorbed metals from microscopic algae after the completion of the process.

Sustainable biosorption of Methylthioninium Chloride in wastewaters using new Cystoseira barbata seaweed: Equilibrium isotherm, kinetic modeling and mechanism analysis

Due to its climatic diversity and geographical position, Morocco is one of the most productive countries of seaweed in the world. This work aims to study the Methylthioninium Chloride (referred to as Methylene Blue) adsorption from wastewater using raw marine seaweed C.barbata that are considered as one of the important algae that are responsible for pollution in the Mediterranean Sea. different factors such as biomass dose, pH, and contact time were examined to demonstrate their impact on the biosorption process. The contact time studied revealed that biosorption of Methylene Blue reached equilibrium in 55 min. The biosorption data was subjected to the kinetic models Pseudo-first and pseudo-second order. Pseudo second order model was aligned with the adsorption data, whereas data didn’t fit pseudo first order model. Adsorption data were modelled with Freundlich and Langmuir isotherm equations at room temperature. The maximum adsorption capacity estimated was 29.56 mg/g based on Langmuir isotherm model. Thus, C. barbata can be regarded as a valuable natural biosorbent for the treatment of wastewaters containing toxic dyes.

Modeling and biosorption potential of Aspergillus heteromorphus for treatment of lead contaminated wastewater

Dead biomass of the fungus species Aspergillus heteromorphus was used to remove Pb (II) ions from electroplating industrial effluents. The optimum process variables for biosorption of Pb (II) ions from aqueous and lead contaminated wastewater were determined using Response Surface Methodology (RSM). These variables included temperature (20–40 °C), metal ions concentration (20–100 mg/L), pH (2.0–6.0), and biomass dose (0.5–2.5 g/L). A total of 29 Box–Behnken design matrix RSM experiments were undertaken for this purpose. The studies were designed using a quadratic model to investigate the interacting effects of process variables. The significance of independent variables was 0.0001, indicating that they are important in the biosorption process. Model terms that have a value of "Prob > F" < 0.0500 are significant for biosorption. The best temperature was observedas 32 °C, along with a biomass dose of 2.4 g/L at pH 5.0, and with the initial concentration of Pb (II) ions (65 mg/L) was found to be optimum for biosorption. A. heteromorphus was able to remove Pb (II) ions up to 91% from aqueous solution under above mentioned ideal conditions. However, from electroplating industrial effluent the Pb (II) ions removal efficiency of A. heteromorphus was observed as 32%.

Utilization of Waste Straw Biomass in Suspension Magnetization Roasting of Refractory Iron Ore: Iron Recovery, Gas Analysis and Roasted Product Characterization

The straw-type biomass, as a green and alternative reductant for the suspension magnetization roasting (SMR) of iron ores, is proposed. The roasted products are investigated at a roasting temperature of 750 °C, the roasting time of 7.5 min and the biomass dose of 25%. The iron phase results indicate that hematite ores were reduced to magnetite by the biomass, and the magnetization transformation increased from 0.64 A·m2·g−1 to 36.93 A·m2·g−1. The iron ore microstructure evolutions of holes and fissures are detected by SEM-EDS. The biomass pyrolyzed to form CO2, CO, CH4, H2O, H2, C=O, benzene skeleton, C-Hand C-O compounds at 200–450 °C, while the mass loss of the magnetization roasting process occurred at 450–750 °C by using TG-FTIR. The GC/MS results showed that the organic gases preferred to produce the O-heterocycles at 329 °C while the hydrocarbons were dominant at the high temperature of 820 °C for the hematite ore and biomass mixture. The gas composition analysis explained that the reducing gaseous products (CO, CH4 and H2) were used as a reductant and consumed obviously by hematite ore in the SMR process. The innovative utilization of biomass waste was effective for iron recovery of hematite ore and contributes to the reduction of greenhouse gases and the protection of the environment.

Malachite green sequestration from aqueous system by untreated &lt;i&gt;Dacryodes edulis&lt;/i&gt; seed

This paper presents an assessment of the kinetics and thermodynamics of malachite green (MG) abstraction from an aqueous system onto untreated pear seed (Dacryodes edulis) biomass as an adsorbent at pH 12. The experiments were conducted in batches at 25 °C, with a biomass dose of 0.5 g, and at different durations (5 to 240 minutes) using a 50 mg/L malachite green dye solution. The kinetics data were examined using four models: pseudo-first-order, pseudo-second-order, intraparticle, and Elovich models. The fallouts indicated that the pseudo-second-order model represented the process’ kinetics well, with R2 values of 0.9998, rate constant, 0.346 g/mg/min, and a 90% adsorption efficiency. Thermodynamics study revealed a negative free energy change, ΔGº, indicating a feasible and spontaneous process that is endothermic, having a positive ΔHº. Comparing the findings with the findings of others reveals that malachite green adsorption onto various adsorbents is usually endothermic and follows the Pseudo-second-order mechanism most times. Overall, untreated pear seed biomass has the potential as an alternative to traditional adsorbents for extracting malachite green from an aqueous medium.