Biomass Dosage Research Articles

RETRACTED: Elimination of Lead by Biosorption on Parthenium stem powder using Box-Behnken Design

Reports on the presence and toxicity of Pb2+ in various chemical industrial effluents energized researchers to investigate several feasible, efficient, precise, and sensitive techniques for determining and removing Pb2+ from aqueous systems. The current work proposes the adsorption of Pb2+ onto the stem of parthenium as a continuation of a series of investigations. In order to find the ideal circumstances for the most effective removal of lead, optimization of Pb2+ sorption potential-affecting factors, such as pH, contact duration, temperature, adsorbent dosage, and concentration of Pb2+ as sorbate, were investigated. The response surface approach was used to assess experiments that were carried out using a rotatable Box-Behnken design (BBD) (RSM). The influence of three independent variables—the pH of the precursor solution (4–5), the initial lead content (15–25 mg/l), and the dose of biomass (20–40 g/l)—were assessed in response to the biosorption process. The optimum pH, lead ion concentration, and biomass dosage for lead biosorption were ascertained to be 5 pH, 20 mg/L, and 30 g/L, respectively. The Parthenium stem powder can reduce the concentration of lead in an aqueous solution by up to 72.74% for 20 mg/l at pH=5 and 260 °C. It has been shown that 1.5 g/100 ml of parthenium stem powder and a 50-minute equilibrium duration are the most effective parameters. The amount of lead absorbed from the aqueous solution increases with an increase in the adsorbent's dosage. Freundlich and Langmuir models in both linear and nonlinear variants were used to comprehend the nature of the adsorption process. By analysing the kinetics and thermodynamics of the process, the feasibility and viability of the sorption process were assessed. The adsorption process was quite rapid, according to the kinetic analyses, and equilibrium was attained after 50 min of contact time. The spontaneous nature of the adsorption process was revealed by the negative values of free energy change. Studies on thermodynamics showed that reactions were exothermic, although research on kinetics revealed that reactions is indeed pseudo-second order.

Application of Central Composite Design for Optimization of Adsorption of Chromium(VI) by Spirulina platensis Algae Biomass

Algal biomass from Spirulina platensis has been tested for the adsorption of chromium (VI) in aqueous effluents. The study was conducted using a central composite experimental design. The selected variables were: biomass (0.25–0.75 mg), initial chromium concentration (100–500 mg/L), and contact time (3–8 h). This study proved that spirulina biomass shows good adsorption capacity in the experimental space selected for the central composite experimental design (CCD). The maximum adsorption capacity was 40 mg Cr/g of biomass in the tests with 500 mg/L of Cr(VI) and 0.25 g of spirulina. The statistical analysis confirmed that the adsorption capacity can be modelled using a linear equation that only depends on the initial chromium concentration and the biomass dose. These results suggest that the adsorption of Cr in spirulina raw biomass can be considered in the development of large-scale applications.

Biosorption of lead by a soil isolate Aspergillus neoalliaceus.

This study focused on Pb (II) elimination from aqueous solutions using fungal soil isolate which is identified as Aspergillus neoalliaceus. The sorption of lead with fungal mass studies was performed as a function of pH, biomass dose, contact time, and initial dye concentration. The solution pH value strongly affected the sorption of lead fungal mass. To examine the effect of hydrogen ions on biosorption in solutions containing lead, solutions with different pH values were used and pH 5 was found to be the most suitable pH value for lead removal. Lead biosorption remained very low below pH 4 because of the competing effect of hydrogen ions in the solution. It has been observed that the removal of lead ions based on biosorption with Aspergillus neoalliaceus is better explained by Langmuir isotherm and pseudo-second-order kinetic models compared to other used models. The biosorption of Pb (II) was determined as a spontaneous and endothermic process.

Understanding the effects of low enzyme dosage and high solid loading on the enzyme inhibition and strategies to improve hydrolysis yields of pilot scale pretreated rice straw

The commercial viability of 2G bioethanol production is dependent on cost-effective and efficient enzymatic hydrolysis of biomass at low enzyme and high dry solid loadings. In the present study, rice straw was subjected to a dilute acid pretreatment in a continuous pilot plant (250 kg/day).It was observed that, the glucan conversion yields were reduced by 26% at high solid loading (20% w/w) with low enzyme dosage of 3 FPU/g w/w of in-house developed enzyme (MRJ16). Thus, multiple approaches were investigated to enhance the glucan conversion yields, a) fed batch approach (splitting biomass or enzyme dosage during process), b) additives supplementation (surfactants, metal ions, non-enzymatic proteins and activated charcoal) and c) enzyme blending with accessory enzymes. Results showed that, the 3-stage fed-batch approach enhanced the hydrolysis yield by 12% in comparison to 14.3% increase with the selected surfactant (0.5% w/w Ecosurf). The selected metal salt (NiCl2, 1 mM) increased the glucan conversion by 13.2%, while, the non-enzymatic proteins (5% w/w yeast hydrolysate and yeast extract) improved the yields to 14.8% and 14.4%, respectively. The activated charcoal at a concentration of 0.5% w/w enhanced the hydrolysis yields by 14.4%. Further, 15.1% increase in sugar yield was obtained by supplementing the in-house produced enzyme (MRJ16) with xylanase from Thermomyces lanuginosus and BGL from Penicillium janthinellum EMS-UV-8. Finally, a unique optimized strategy was developed on the basis of selected approaches and parameters which demonstrated 24.7% higher saccharification in comparison to control. To the best of our knowledge, this is the only study available in literature where; a wide range of strategies were studies on a single feedstock (i.e. rice straw) pretreated at pilot-scale and determine its effect for improved enzymatic hydrolysis. Furthermore, developed process helps us to save (almost 2X) expensive enzyme to achieve same level of glucan conversion (∼62.0%) to make the overall process cost effective by using cheap and easily available additives. The current study also provided an in-depth understanding of enzyme inhibition at low enzyme dosages and high solid loadings in an industrially relevant scenario.

Bioremoval of some heavy metals from aqueous solutions by two different indigenous fungi Aspergillus sp. AHM69 and Penicillium sp. AHM96 isolated from petroleum refining wastewater

Myco-remediation of heavy metals using indigenous fungi of different petroleum refining areas in Egypt was applied. Among the physicochemical parameters determined in these refineries effluents, the highest levels of heavy metals were recorded for the most toxic heavy metals Fe3+ and Co2+. The fungal isolates under the isolation codes AHM69 and AHM96 isolated from the mycobiome of Mostorod and Tanta refineries, respectively showed the best bioremoval efficiency toward heavy metals from the real wastewater mixture and polycyclic aromatic hydrocarbons from aqueous solutions. Based on phenotypic and genotypic analysis they were identified as Aspergillus sp. AHM69 and Penicillium sp. AHM96. The optimum conditions for the best bioremoval of Fe3+ and Co2+ from aqueous solutions by Aspergillus sp. AHM69 were live biomass, temperature 45–55 °C, pH 4.5–5.0, contact time 180 min, metal concentration equal to 1000 and 400 mg/L of Fe3+ and Co2+ with live fungal biomass dose of 0.5% and 0.4% with Fe3+ and Co2+, respectively. Concerning to the biomass of Penicillium sp. AHM96, the optimum operation conditions for the best removal of Fe3+ and Co2+ were 45 °C, pH 5.0 and 400 mg/L of Fe3+ with 1.0% biosorbent dosage or 1000 mg/L of Co2+ with 0.5% biosorbent dosage for 180 min as process time. Furthermore, FTIR analysis showed masking, shifting, creating and absenting of different functional groups in the fungal biomass surface of AHM96 and AHM69 strains in the presence of Fe3+ and Co2+ compared to unloaded biomasses. Microscopy with Energy Dispersive X-ray analysis (SEM-EDX) indicated that the removal of Fe3+ and Co2+ by fungi AHM69 and AHM96 was via biosorption and bioaccumulation on the biomass surface. Our results suggested that in the near future, fungal treatment is likely to outperform and replace other chemical and biological treatments in industrial wastewater treatment for oil refining.

Chemical seed treatment and mycorrhizal inoculation provide better development and nutrition of common bean plants.

Chemical seed treatment is an established practice in agriculture to protect crops from soil-borne pathogens and pests. Arbuscular mycorrhizal fungi (AMF) benefit plants by extending soil exploration as well as water and nutrient uptake. The objective of this work was to analyze the effects of combinations of seed treatments with doses of inoculant containing Rhizoglomus intraradices on vegetative development, root colonization and nutrition of Phaseolus vulgaris plants and soil microbiota. Seed treatment benefited the vegetative development and nutrition of beans, with the treatments metalaxyl + fludioxonil + tiabendazole and pyraclostrobin + thiophanate methyl + fipronil standing out regarding the contents of nitrogen (N), phosphorus (P), iron (Fe) and zinc (Zn) of the aerial parts. Mycorrhizal inoculation linearly increased dehydrogenase activity, root biomass and total plant biomass, with increments reaching 27%. There was an interaction between seed treatment and inoculation dose for aboveground biomass and the contents of potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), manganese (Mn) and root colonization, with expressive results for the combination of the two highest doses of inoculant with metalaxyl + fludioxonil + tiabendazole or pyraclostrobin + methylthiophanate + fipronil in the seeds. Chemical seed treatment and mycorrhizal inoculation benefited bean plants and their nutritional status. The best combinations for the bean crop were metalaxyl + fludioxonil + tiabendazole with 41.4mg of the inoculant per 100 seeds and pyraclostrobin + thiophanate methyl + fipronil with 62.1mg of the inoculant per 100 seeds. © 2022 Society of Chemical Industry.

Experimental Modeling Investigations on the Biosorption of Methyl Violet 2B Dye by the Brown Seaweed Cystoseira tamariscifolia

Methyl violet 2B dye is a major contaminant that is detrimental to both humans and aquatic microorganisms, thus it should be eliminated from water. In the current investigation, the biosorption of methyl violet 2B dye onto the brown seaweed Cystoseira tamariscifolia biomass as a sustainable low-cost biosorbent was examined by varying biosorption parameters. Biomass dosage of 7 g/L, pH 6, a temperature of 45 °C, a 60 min contact time, and a 30 mg/L initial dye concentration were determined to be the optimum biosorption conditions. Data obtained were interpreted by thermodynamic, isothermal, and kinetic models. The thermodynamic studies demonstrated that the process of dye biosorption was random and endothermic. The data were best described by Langmuir, Dubinin–Radushkevich, and Temkin models. According to the Langmuir equation, the maximal biosorption capacity (qmax) was 10.0 mg/g. Moreover, the pseudo-second-order mechanism is dominant, and chemical biosorption might represent the rate-controlling stage in the biosorption process. However, intraparticle diffusion revealed a boundary layer effect. A scanning electron microscope, energy-dispersive X-ray spectroscopy, the point of zero charge, and Fourier Transform Infra-Red were applied to characterize the algal biomass, exhibiting its remarkable structural properties and the availability of several functional groups. Additionally, ion exchange, electrostatic force, and hydrogen bonding formation are all proposed as biosorption mechanisms. As a result, C. tamariscifolia was evaluated to be a sustainable biosorbent for dye biosorption from aqueous solutions.

Adsorption Capacity of Lead (II) (Pb2+) in Aqueous Solution by Brown Seaweed (Fucus spiralis)

The sorption uptake of lead by marine brown alga Fucus spiralis was investigated in bimetallic solutions. The experimental data fitted very well to Langmuir model. In bimetallic systems, the affinity of biomass for lead and cadmium increased and the sorption uptake of these metals was not affected by increasing concentrations. However, in solutions with both metals there was a significant mutual decrease of their sorption levels at high concentrations of the other metal. There is practical removal up to 100 ± 4% for biomass dosage 4.0 ±0.1 g which correspond to lowest adsorbed amount of 0.25 ± 0.1 mg/g. The highest adsorbed value was recorded with biomass dosage 0.25 ± 0.1 g but with the lowest percentage removal of 92.50 ± 6%. In this study at initial metal concentration of 10 mg/L the highest metal removal of 96% was achieved.

Histopathological changes in root and stem of mungbean exposed to Macrophomina phaseolina and dry biomass of Chenopodium quinoa.

Mungbean production is affected by a fungal pathogen Macrophomina phaseolina. A pot experiment was carried out to check the effect of quinoa (Chenopodium quinoa Willd.) dry biomass on the histopathological features of mungbean exposed to M. phaseolina. For this, 1%, 2% and 3% (wt/wt) of C. quinoa dry biomass was mixed in the soil inoculated with M. phaseolina. The highest disease incidence (36%) was recorded in the positive control (only M. phaseolina). Different treatments of quinoa dry mass reduced disease incidence to 4-7%. After 4 weeks of germination, stem and root sections were stained in phloroglucinol-HCl, ferric chloride and Lugol's iodine stains for the detection of lignin, polyphenols and starch granules, respectively, and studied under light microscope. Plants of positive control showed damaged cells, and heavy deposition of lignin, phenolics and starch granules as compared to plants of the negative control and those grown in the soil amended with different doses of dry biomass of quinoa. For better understanding, plant root and stem sections were studied under a scanning electron microscope. Plant sections from positive control exhibited the presence of M. phaseolina sclerotial bodies and hyphal growth, whereas in negative control normal cell structures were observed. However, C. quinoa amended stem and root sections revealed the presence of high gel deposition with normal cell structures and no pathogen establishment. This study concludes that application of C. quinoa is an effective and natural remedy to activate the resistance mechanism in plants and to combat the adverse effects of M. phaseolina. HIGHLIGHTS: Macrophomina phaseolina causes charcoal rot in mungbean. Chenopodium quinoa amendment significantly reduced incidence of charcoal rot disease. M. phaeolina increased concentrations of polyphenols, lignin and starch granules in mungbean.

The Efficiency of Moringa oleifera seed biomass in the Removal of lead (II) ion in aqueous solution Adsorption capacity of Moringa oleifera in the removal of Pb(II) ion from polluted water

This study was based on the evaluation of the efficiency and applicability of Moringa oleifera seed biomass (MOSB) as adsorbent in the removal of Lead (Pb) in water. The study was justified by the toxic nature of the study metal as the current conventional processes of heavy metals’ removal are not environmentally friendly and chemical coagulant very exorbitant. Fourier transform Infrared (FTIR) analysis was used to characterise the Moringa oleifera seeds biomass functional groups that may be present in the adsorption of metal ions. The observed components were the carboxylic acid and amine functional groups (-COOH and -NH). The effects of contact time, adsorbent dosage, metal ion concentration and pH were studied. Pb (II) ion had a maximum adsorption capacity of 90% at pH 5, room temperature, and 0.8 g dose of Moringa oleifera seeds biomass. The adsorption data fit better with the Langmuir than Freundlich isotherm models. From the Langmuir model, the sorption capacity (qm) of MOSB for Pb (II) ion was 6.19 mg/g. The results showed that Moringa oleifera seed biomass is an effective adsorbent in the removal of the studied heavy metal in water.

Characterization of biosorption potential of Brevibacillus biomass isolated from contaminated water resources for removal of Pb (II) ions.

Various activities of different industries are found to be the main reason for water pollution with heavy metals. Use of microorganisms that are tolerant even of a high concentration of metal ions could be a valuable tool for remediation of contaminated water resources. In the present study, microorganisms that showed high resistance to lead ions were isolated and evaluated for biosorption efficiency for removal of lead ions from waste water. Biochemical identification and 16S rRNA gene sequence analysis indicated that the isolated strain was Brevibacillus. The conditions of pH, biomass concentration, temperature, time, agitation and Initial concentration of metal for biosorption of Pb (II) were optimized. Based on induction coupled plasma optical emission spectroscopy (ICP-OES) analysis, the biosorption efficiency of Brevibacillus at optimized conditions of initial metal concentration of 150 μg/mL, 1 g/L of biomass dose, pH 6.0, 40 °C, for 12 h at 80 rpm was 78.58% and the biosorption capacity (qe) is 128.58 mg/g of the biosorbent. Of the three isotherm models investigated, the Freundlich isotherm model was identified as a good fit with high correlation coefficient, while kinetic data followed the pseudo first order model as best fit. Surface characterization by scanning electron microscopy (SEM) analysis revealed morphological changes with a bulged rod-shape cell having metal depositions and rough texture. The presence of lead within the cell was detected by transmission emission microscopy (TEM). The key functional groups that participate in biosorption were analyzed by Fourier transform infrared (FTIR) spectroscopy and were found to be carboxyl, hydroxyl, amino and phosphate groups. From the real-time study, it proves that the biomass of Brevibacillus can be used as a promising biosorbent for removal of metals including lead from waste water.

Biosorption of Acid dye by Jackfruit Leaf Powder: Isotherm, kinetics and Response surface methodology studies

A green adsorbent derived from Jackfruit leaf powder (JLP) was used to eliminate Acid Yellow 99 (AY 99) dye from an aqueous medium in this study. We checked the effect of pH, biomass dosage, and temperature (process parameters) on the adsorption potential of AY 99 was explored using the CCD model integrating the RSM approach. At a pH of 2.5, biosorbent dosage of 4 gL-1, and a 30°C temperature, maximum removal was preferred. ANOVA was incorporated to observe the importance of experimental variables and their interactions. The solution pH (A) and biomass dose (C) had the greatest effects on the decolorization of AY 99, according to the findings. ANOVA was used to identify the most important factors, which included two independent variables (A and C) and two quadratic model terms (A2 and C2). The kinetic data were effectively interpreted using a pseudo 2nd order with film diffusion model combination, indicating the chemisorptions phenomenon. Following the model of Langmuir isotherm, the utmost capacity for adsorption was determined to be 418.15 mg g-1 in terms of initial dye concentration. The findings of the maximum adsorption capacity showed that JLP could be employed as a useful adsorbent to eliminate AY 99 from its aqueous medium.

Potential application of Fusarium fungal strains (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) for removal of Tl (I) ions from water.

Water pollution caused by heavy metals poses a serious threat to the ecosystem and human health. Among the various treatment techniques for water remediation, adsorption is an efficient method due to its high capacity, low cost, and simplicity. Thallium (Tl) is highly toxic to mammals and its removal from water is gaining increasingly prominent attention. In this study, three fungal strains (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) were tested for removal of Tl (I) from aqueous solutions and showed excellent removal performance. The prepared inactive fungal strains were characterized by XRD, FT-IR, SEM, and XPS analyses. The effects of pH, contact time, biomass dosage, and reaction temperature on the removal efficiency of Tl (I) were systematically investigated. The results indicated that the adsorption isotherm data fit well with the Langmuir model, and the pseudo-second-order model was more consistent with the kinetic data description. The maximum adsorption capacity of the fungal strain (Fusarium sp. FP, Arthrinium sp. FB, and Phoma sp. FR) for Tl (I) was found to be 94.69mg/g, 66.97mg/g, and 52.98mg/g, respectively. The thermodynamic data showed that the sorption process was spontaneous and endothermic. The present study showed that the inactive fungal strains could be a promising adsorbent material for Tl (I) removal.

Biosorption of uranium from aqueous solutions by Azolla sp. and Limnobium laevigatum.

The main goal of this study was to assess alternatives to the current challenges on environmental quality and circular economy. The former is here addressed by the treatment of radioactively contaminated solutions, and the latter by using abundant and low-cost biomass. In this paper, we examine the biosorption of hexavalent uranium (U(VI)) in a batch system using the macrophytes Limnobium laevigatum and Azolla sp. by three operational parameters: biomass dose, metal ion concentration, and contact time. Simulated solutions were firstly addressed with two biomasses, followed by studies with real liquid organic radioactive waste (LORW) with Azolla sp. The batch experiments were carried out by mixing 0.20g biomass in 10mL of the prepared solution or LORW. The total contact time employed for the determination of the equilibrium times was 240min, and the initial U(VI) concentration was 0.63mmol L-1. The equilibrium times were 15min for L. laevigatum and 30min for Azolla sp. respectively. A wide range of initial U(VI) concentrations (0.25-36mmol L-1) was then used to assess the adsorption capacity of each macrophyte. Isotherm models validated the adsorption performance of the biosorption process. Azolla sp. presented a much higher U(VI) uptake (0.474mmolg-1) compared to L. laevigatum (0.026mmolg-1). When in contact with LORW, Azolla sp. removed much less uranium, indicating an adsorption capacity of 0.010mmolg-1. In conclusion, both biomasses, especially Azolla sp., can be used in the treatment of uranium-contaminated solutions.

Optimizing agricultural biomass application to enhance nitrogen removal in vertical flow constructed wetlands for treating low-carbon wastewater

Agricultural biomass waste in rural areas has been identified as an economical solid carbon sources in constructed wetlands (CWs) for treating low C/N ratio domestic sewage. However, little information is available regarding its optimal utilization as a media amendment for enhancing nitrogen removal in CWs. In this study, vertical flow CWs with different walnut peel amendment proportions (0%, 25%, 50%, 75%) were developed to explore the effects of biomass dosage on the treatment performance, nitrous oxide (N2O) emission and microbial metabolites. Results showed that the addition of biomass significantly enhanced the denitrification performance in all CWs, and the higher total nitrogen (TN) removal efficiency (91.14–97.16%) was achieved in CWs with the optimal dosage of 25%. While the addition of biomass resulted in a slight increase in N2O emission (20.56–270.13 μg m−2 h−1) compared with control systems. Additionally, the biomass addition increased the accumulation of extracellular polymeric substances (EPS) by facilitating microbial processes. Higher total EPS production was observed in CW with 25% biomass, and the proportion of tightly bound EPS (48%) dominated in the total EPS in different CWs.

Effect of the optimal combination of bituminous coal with high biomass content on particulate matter (PM) emissions during co-firing

The co-firing of bituminous coal with woody biomass provided an available approach for cutting carbon emissions. In this work, a study on the application of high blending ratios of biomass with coal in co-firing was experimentally conducted in a lab-scale drop tube furnace (DTF) to reduce CO2 emissions and control deposition and corrosion due to the particulate material (PM) yield on the heating surface. Two kinds of woody biomass were blended with two kinds of bituminous coals at dosages of 5 wt%, 15 wt% and 30 wt% to investigate the PM emissions of different combinations during co-firing. With the addition of biomass, the experimental results show that the PM emission during co-firing may greatly increase or remain approximately stable compared with that during the single combustion of coal, which is dominantly determined by the combination of coal and biomass. To quantitively understand this effect, a mathematical method for the prediction and verification of PM yield during co-firing was developed by using a FactSage calculation based on the computer‐controlled scanning electron microscopy (CCSEM) analysis of raw fuel and fly ash. The predicted proportions of sticky particles with a liquid amount of >70 wt% demonstrate a significant difference with the variation in fuel type and biomass dosage during co-firing. According to predictions, 45.3% more sticky particles can be produced due to the diversity of added biomass when co-fired with the same kind of coal, conversely resulting in a 54.8% suppression of particles with an aerodynamic diameter of 2.5 μm or less (PM2.5) emissions. The morphological and elemental distribution of PM further validates that the liquid substance formed can be the decisive factor in generating sticky particles to control the formation of precursors by adsorption of alkali vapor or agglomeration of fine grains, thus inhibiting the PM yield with the addition of woody biomass during co-firing. The optimal combination for the co-firing of coal with high concentrations of biomass can be ascertained to simultaneously realize the reduction of carbon and PM emissions, which could provide a novel approach for the survival and development of coal-fired plants.

Biosorption of arsenite (As[III]) using Saccharomyces cerevisiae SRCM 501804 isolated from Korean turbid rice wine

The potentiality of Saccharomyces cerevisiae SRCM 501804 to remove arsenite (As[III]) in an aqueous solution was investigated in this study. The S. cerevisiae SRCM 501804 was isolated from Korean turbid rice wine (Makgeolli). The S. cerevisiae SRCM 501804 was characterized by phylogenetic analysis, Fourier transform infrared (FT-IR) spectroscopy, visual minerals technologies (MINTEQ) model, and point of zero charge (pHpzc). The relationship between the factors (pH, biosorbent dosage, contact time, and concentration) and biosorption capacity was investigated. The S. cerevisiae SRCM 501804 was removed 31.1–90.1% of the As(III) depending on the initial biomass dosage within 1 h. Co-existing anions in aqueous solution showed a negative influence on the biosorption performance of As(III) in the order Cl− > NO3 − > SO4 2− > CO3 2−. The results of isotherms and kinetics suggested the Langmuir (R 2 > 0.95) and Pseudo-second order (R 2 > 0.99) models fit well with the equilibrium experimental data. The maximum biosorption capacity (qm ) of S. cerevisiae SRCM 501804 biomass for As(III) was found to be 113.9 mg/g from Langmuir isotherm. Based on the results, it can be concluded that the biomass of S. cerevisiae SRCM 501804 could be used as an effective bio-sorbent for As(III) biosorption in an aqueous solution.

Batch studies of hexavalent chromium biosorption from mining wastewater using Aspergillus niger

The effects of selected process parameters in the biosorption of chromium (VI) ions for wastewater treatment using Aspergillus niger were studied whilst keeping temperature and pH constant. The biosorption capacity was observed to be optimum at 15 h contact time, 2.8 g biomass dose and 200 rpm agitation speed. The Jovanovic isotherm model best represented the biosorption equilibrium data, and the equilibrium biosorption capacity was found to be 0.0574 mg/g. The biosorption kinetics was investigated, and the pseudo-second-order kinetic model gave the best fit concerning the generated biosorption data according to linear regression analysis. Thermodynamic study of the biosorption process ascertained the values of standard thermodynamic parameters, including ΔGo, ΔHo, ΔSo, which helped characterize the biosorption process to be exothermic, physical, and spontaneous.

Removal of minocycline from high concentrated aqueous medium by nonliving and lipid-free Chlorella sp. biomass

This work evaluated the removal of minocycline (MC) by the nonliving Chlorella sp. biomass (NLB) and modified by a lipid extraction procedure (LEB). Both biomasses have different morphology (NLB: globular-like; LEB: flakes and blocks) and size distribution. The pH showed a significant synergistic influence on MC removal (p < 0.05). MC initial concentration (C0) and biomass dosage significantly interact, suggesting that LEB agglomeration decreased removal. NLB removed 90.8 ± 1.3% of MC and LEB 80.8 ± 1.4% at C0 = 53.89 mg/L, 50 mg of biomass and pH 10. The adsorption kinetics and isotherms suggested multilayer formation by physical and chemical adsorption on heterogeneous and macroporous surfaces. According to results, NLB as an adsorbent had an economic disadvantage because of production costs despite good removal efficiency. However, it is possible to take advantage of the biomass after removing value-added compounds (LEB) as a zero-waste strategy.

SIMULTANEOUS ADSORPTION OF TETRACYCLINE AND AMOXICILLIN BY CLADOPHORA AND SPIRULINA ALGAE BIOMASS

Adsorption studies were performed at different initial Tetracycline (TC) and Amoxicillin (AMO) concentration, different biomass dosage and type, contact time, agitation speed, and initial pH. In the batch mode were investigated. The optimum pH of solutions is 6.5 for TC and 5 for AMO, agitation speed 200 rpm and concentration 50 ppm. The results in FTIR showed that there were -OH and amides (N-H) and other functional groups on the surface of Cladophora and Spirulina algae. The equilibrium isotherm data were modeled with Freundlich, Temkin, and Langmuir isotherm models. The data best fitted with the Langmuir model. The maximal adsorption capacity from the Langmuir model was (9.86, 20. 5 mg/g) for TC and (7.89, 17.4 mg/g) for AMO on Cladophora and Spirulina algae, respectively. Finally, the pseudo-second-order kinetic model was best fitted the experimental kinetic data of TC and AMO onto Cladophora and Spirulina algae biomass with a high coefficient of determination between 0.97 and 0.99. Cladophora and Spirulina algae, low-cost and eco-friendly adsorbents, can be used to adsorb the TC and AMO from the solution.