Biosorption Process Research Articles

Biosorption of Chromium and Nickel from Industrial Oil Mill Wastewater Using Groundnut Pod Waste Activated Carbon

Groundnut shell activated carbon was developed and characterized by chemical activation using phosphoric acid (H3PO4) for the uptake of Cr and Ni in a batch biosorption process. The purpose of this study was to reduce the spread of heavy metals in industrial oil mill wastewater. In this study characterization of activated carbon using, surface chemistry (FTI-IR), surface area (BET), surface morphology, and elemental identification (SEM/EDX) were all carried out, and the BET surface area was 689.41 m2/g for groundnut shell activated carbon. This study was also executed to determine the optimum biosorption efficiency parameters for Cr and Ni removal using Response Surface Methodology (RSM) to obtain maximum biosorption efficiency. The factors considered were temperature (25-55oC), adsorbent dosage (1-3 g) and contact time (1-2 hrs). Biosorption efficiency was the response. ANOVA analysis was carried out to analyse the most effective factor in experimental design response. The optimum conditions for removal of Cr and Ni were adsorbent dosage 0.40 g, contact time 1.1 hr and temperature 42.02 oC, which shows the maximum biosorption efficiency of 97.1% for Cr removal and 94.8% for Ni removal. Isotherm models analyses showed that the biosorption process was best fitted to Langmuir model and was physical. Results of the kinetic studies and thermodynamic parameters revealed that the biosorption process followed a pseudo-second-order, endothermic, and spontaneous in nature.

Development of New Biosorbent Based on Crosslinked Chitosan Beads with High Brilliant Blue FCF Removal Efficiency.

Effluents containing synthetic anionic dyes can pose a risk to ecosystems, and they must be treated before their release to the environment. Biosorption, a simple and effective process, may be a promising solution for treating these effluents. In this work, chitosan beads were crosslinked with epichlorohydrin to produce a highly stable and performant biosorbent to remove Brilliant Blue FCF dye. The biosorbent was characterized by determining the functional groups on its surface, as well as its elemental composition, crystallinity, and surface morphology. Crosslinking with epichlorohydrin significantly improved the biosorption capacity of chitosan beads. A maximum biosorption capacity of 600 mg/g corresponding to 99% removal efficiency was observed at pH 3.0, a biosorbent dose of 0.5 g/L, an initial dye concentration of 300 mg/L, a contact time of 10 h, and a temperature of 323 K. The biosorption of Brilliant Blue FCF dye in chitosan beads crosslinked with epichlorohydrin was well described by the Langmuir isotherm and followed an adsorption kinetic of pseudo second order. The thermodynamic parameters indicate a spontaneous biosorption process. The presence of anions such as NO3- and SO42- could interfere with the biosorption of Brilliant Blue FCF on the chitosan crosslinked beads, but Cl- did not interfere in biosorption process. Over three biosorption/desorption cycles, the biosorbent showed a removal efficiency of 97% and a desorption rate of over 98%. Chitosan is available worldwide and is a low-cost biomaterial, presenting high potential to be used as a biosorbent to treat industrial effluents containing anionic compounds, such as dyes.

Dictyota bartayresiana a sustainable biosorbent for the decolorization of reactive blue 19 – optimization, equilibrium, desorption and toxicological studies

The present study aims to investigate the dye decolorization efficiency of the brown seaweed Dictyota bartayresiana against reactive blue 19 (RB19) dye. The process variables namely dye and biosorbent concentration, pH and incubation time were optimized through BBD based RSM for achieving enhanced dye decolorization. The experimental data well fitted into Freundlich isotherm and proving the heterogenous adsorption of RB19. The Temkin and Dubinin – Radushkevich isotherm models showcased the endothermic and chemisorption mediated adsorption of RB19 onto D. bartayresiana. The pseudo second order kinetic model exhibited the chemisorption assisted adsorption and the Weber Morris kinetic model proved that the intra particle diffusion was not the rate limiting step in the adsorption of RB19 onto D. bartayresiana. Thermodynamic studies revealed the spontaneous, feasible and endothermic process of biosorption. Interaction between the dye and the biosorbent was assessed through UV-Vis, FT-IR and SEM which confirmed the process of decolorization. Desorption and regeneration studies revealed that 73% of the dye was desorbed in the first cycle using 0.1 M NaOH as eluent with regeneration efficiency of 68% which reduced in subsequent cycles highlighting the reusability of the biosorbent. Toxicity assessments of untreated and D. bartayresiana treated RB19 dye solution were examined on the microflora, brine shrimp and fenugreek and the results revealed the nontoxic nature of D. bartayresiana treated RB19 solution. Thus, this study provides valuable insights on utilization of D. bartayresiana as an eco-friendly biosorbent for the decolorization of RB19 and affirms its safe use in various biological applications.

Removal of Ampicillin with Nitrifying Cultures in a SBR Reactor.

The presence of antibiotics in wastewater discharges significantly affects the environment, mainly due to the generation of bacterial populations with multiple antibiotic resistances. The cometabolic capacity of nitrifying sludge to simultaneously remove ammonium (NH4+) and emerging organic contaminants (EOCs), including antibiotics, has been reported. In the present study, the removal capacity of 50mg ampicillin (AMP)/L by nitrifying cultures associated with biosorption and biotransformation processes was evaluated in a sequencing batch reactor (SBR) system. The contribution of nitrifying enzymes (ammonium monooxygenase (AMO) and nitrite oxidoreductase (NOR)) and β-lactamases in AMP biodegradation was evaluated using specific inhibitors in batch cultures. AMP was 100% eliminated after 5h since the first cycle of operation. The sludge maintained its ammonium oxidizing capacity with the total consumption of 102.0 ± 2.5mg NH4+-N/L in 9h, however, the addition of AMP altered the nitrite-oxidizing process of nitrification, recovering 30 cycles later at both physiological and kinetic level. The kinetic activity of the nitrifying sludge improved along the operating cycles for both AMP removal and nitrification processes. The elimination of 24% AMP was attributed to the biosorption process and 76% to biotransformation, wherein the AMO enzyme contributed 95% to its biodegradation. Finally, the repeated exposure of the sludge to AMP for 72 operating cycles (36days) was not sufficient to detect β-lactamase activity. The cometabolic ability of ammonium-oxidizing bacteria for biodegrading AMP could be employed for bioremediation of wastewater.

Optimization of biosorption process for activated biomass preparation using statistical method: kinetic, equilibrium, and thermodynamics

Optimization of biosorption process for activated biomass preparation using statistical method: kinetic, equilibrium, and thermodynamics

Batch biosorption studies of ammonical nitrogen (NH3-N) ions from aqueous solutions using the ubiquitous bacteria Klebsiella sp.: equilibrium, kinetic, and thermodynamic studies

BackgroundThe ubiquity of ammonical nitrogen (NH3-N) in aquatic habitats is a contradictory phenomenon since it serves a crucial function in maintaining these ecosystems, yet when levels are too high, they can have adverse effects on ecological balance and human welfare. An extensive set of batch tests were used in this study to see how well the bacterial species Klebsiella sp. broke down ammonical nitrogen (NH3-N).ResultsThe research results established that Klebsiella sp. has a remarkable capacity to adapt to ammonical nitrogen concentrations of up to 125 mg/l over a long period of time. The adaptation process depends on several factors such as biomass abundance, ammonical nitrogen concentration, pH, and temperature. This study identified the optimal method for the absorption of ammonical nitrogen (NH3-N) from a solution at a concentration of 100 parts per million (ppm), achieving an efficiency of 89 ± 1.5% mg/g under specified conditions. At a pH of 6.5, the adsorbent dosage was 0.3 g in 50 milliliters of NH3-N at a temperature of 26 degrees C. We used an extensive range of analytical techniques, such as Scanning Electron Microscopy, Xray diffraction, Brunauer-Emmett-Teller analysis, Transmission Electron Microscopy, and Fourier-Transform Infrared Spectroscopy, to confirm the accuracy of our results. The study also showed that the biosorption process closely followed pseudo-second-order kinetics and the Langmuir model, which propose that both physical and chemical processes were involved. The thermodynamic studies also showed that this process can happen on its own and can be used in industry.ConclusionThis study emphasizes the great ability of Klebsiella sp. to reduce NH3-N, providing important knowledge for water quality management and aquatic ecosystem preservation.Graphical

The sorption of algal organic matter by extracellular polymeric substances: Trade-offs in disinfection byproduct formation influenced by divalent ions.

Disinfection by-products (DBPs), formed from biofilm extracellular polymeric substances (EPS) and organic matter during regular disinfection practices in drinking water distribution systems, poses a potential threat to drinking water safety. However, the diverse DBP formations induced by the intertwined algal organic matter (AOM) and bacterial EPS remains elusive. In this study, we show substantial variations in EPS and DBP formation patterns driven by AOM biosorption with divalent ions (Ca2+ and Mg2+). Divalent ions in bulk water can significantly inhibit carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs) formation. Mechanistically, divalent ions promote the complexation of negative charged groups and thus inhibit C-DBP formation, while the hindering chlorine substitution of hydrogen atoms on α‑carbon and amine groups reduces N-DBP formation. Conversely, Ca2+ and Mg2+ could facilitate biosorption processes that increased the yields of C-DBPs and N-DBPs. Both EPS and AOM provide halogenated reactive sites for DBP formation, exhibiting diverse aromatic substances and unsaturated (lignin and tannins) compounds. Our results highlight divalent ions acting as a fundamental driving force in DBP formation, suggesting the need for cautious monitoring of divalent ions in karst water.

Removing drug residues from water using biosorbents: a review of academic works

Water pollution by emerging contaminants (EC) is one of today's most significant environmental problems. Among these are pharmaceutical compounds, which are increasingly being discarded into watercourses. Due to the toxicity caused by residues of these substances, it is essential to develop techniques to remove these contaminants. Thus, through bibliographic research, this study investigates Brazilian academic works such as theses and dissertations that report studies on removing pharmaceutical residues from water using biosorption processes as a high-potential, low-cost alternative for decontamination. An advanced search was carried out in the Brazilian Digital Library of Theses and Dissertations, using the words "adsorption" and "pharmaceuticals," considering all the works documented on this database until 2024. After selective reading, the search resulted in 55 academic works on the field. Most of the research investigated the use of activated carbon produced from coconut shell waste, avocado pits, sugarcane bagasse, and sewage sludge as biosorbents, as well as chitosan-based composites, magnetic hybrid materials, wood sawdust, algae biomass, and grape pomace. As for the pharmaceutical residues, the most common contaminants studied were sodium diclofenac, amoxicillin, paracetamol, and ciprofloxacin. Although promising results have been reported using these alternatives for remediating water contaminated by pharmaceuticals, biosorption processes still require further development before they can be fully applied to treat wastewater or supply and spring waters.

Minimum-Run Resolution IV Design for Optimized Bio Removal of Fe2+ Using Enteromorpha intestinalis Aqueous Extract and Its Extract-Coated Silver Nanoparticles.

Biosorbents have demonstrated considerable potential for the remediation of metals in aqueous environments. An aqueous extract of Enteromorpha intestinalis L. (EiE) and its extract-coated silver nanoparticles have been prepared and employed for the removal of iron. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-visible spectroscopy, transmission electron microscopy (TEM), gas chromatography-mass spectroscopy (GC-MS), and zeta potential were employed to characterize the prepared biosorbents. The adsorption properties of the biosorbents were investigated in batch experiments, with a range of factors taken into account, including pH, contact time, initial ion concentrations, biosorbent dosage, and temperature. A minimum-run resolution IV design (MRR-IV) was developed with the objective of optimizing the removal efficiency. The mechanisms of adsorption were investigated using both the Langmuir and Freundlich isotherms. Kinetic studies were conducted using the pseudo-first-order and pseudo-second-order models. A variety of active constituents, including organic acids, lipids, alcohols, and terpenes, were identified through the use of GC-MS, with the findings supported by FTIR spectra. Transmission electron microscopy (TEM) revealed that the nanoparticle size ranged from 5 to 44 nm, while X-ray diffraction (XRD) demonstrated a high degree of crystallinity. A screening study employing the MRR-IV methodology, facilitated by the Design-Experiment, Ver 13., indicates that three factors exert a considerable influence on the biosorption process. The study demonstrated that the biosorption mechanism is pH-dependent, with an optimal pH of 5. The adsorption performance was found to follow Freundlich isothermal models and pseudo-first-order kinetics.

Agro-industrial wastes and their application perspectives in metal decontamination using biocomposites and bacterial biomass: a review.

Contamination of water bodies is a significant global issue that results from the deliberate release of pollutants into the environment, especially from mining and metal processing industries. The main pollutants generated by these industries are metallic wastes, particularly metals, which can cause adverse effects on the environment and human health. Therefore, it is crucial to develop effective and sustainable approaches to prevent their discharge into the environment. Biofiltration is a technique used to remediate contaminated fluids using biological processes. Microorganisms and agro-industrial wastes have been used successfully as biosorbents. Hence, this review emphasizes the innovative use of agro-industrial waste reinforced with microbial biomass as bioadsorbents, highlighting their dual capacity for metal removal through various bioremediation mechanisms. The mechanisms at play in these biocomposite materials, which offer enhanced sustainability, are also analyzed. This study contributes to the advancement of knowledge by suggesting new strategies for integrating reinforced materials in biosorption processes, thus providing a novel perspective on the potential of lignocellulosic-based systems to improve decontamination efforts. On the other hand, it shows some studies where the optimization and scaling-up of biosorption processes are reported. Additionally, the implementation of multisystem approaches, leveraging multiple bioremediation techniques simultaneously, can further enhance the efficiency and sustainability of metal removal in contaminated environments.

Enhanced Lead and Zinc Removal via Prosopis Cineraria Leaves Powder: A Study on Isotherms and RSM Optimization

This study investigates the potential of Prosopis cineraria Leaves Powder (PCLP) as a biosorbent for removing lead (Pb) and zinc (Zn) from aqueous solutions, optimizing the process using Response Surface Methodology (RSM). Prosopis cineraria, commonly known as Khejri, is a drought-resistant tree with significant promise in environmental applications. The research employed a Central Composite Design (CCD) to examine the independent and combined effects of key process variables, including initial metal ion concentration, contact time, pH, and PCLP dosage. RSM was used to develop mathematical models that explain the relationship between these factors and the efficiency of metal removal, allowing the determination of optimal operating conditions. The experimental results indicated that the Langmuir isotherm model was the most appropriate for describing the biosorption of both metals, suggesting favorable adsorption characteristics. Additionally, the D-R isotherm confirmed that chemisorption was the primary mechanism involved in the biosorption process. For lead removal, the optimal conditions were found to be 312.23 K temperature, pH 4.72, 58.5 mg L−1 initial concentration, and 0.27 g biosorbent dosage, achieving an 83.77% removal efficiency. For zinc, the optimal conditions were 312.4 K, pH 5.86, 53.07 mg L−1 initial concentration, and the same biosorbent dosage, resulting in a 75.86% removal efficiency. These findings highlight PCLP’s potential as an effective, eco-friendly biosorbent for sustainable heavy metal removal in water treatment.

Biosorption, Recovery and Reuse of Cu(II) by Penicillium sp. 8L2: A Proposal Framed Within Environmental Regeneration and the Sustainability of Mineral Resources

The copper contamination of terrestrial and aquatic ecosystems is a major global environmental problem. Copper is a metal used in many industrial and agricultural processes that is bioaccumulative and highly toxic, making its elimination, recovery and reuse of great interest for environmental sustainability. At the same time, the use of ubiquitous microorganisms is presented as a crucial tool in the field of the sustainability of mineral resources, which in many cases end up as bioaccumulative pollutants, since they can allow the recovery of metallic ions present in low concentrations and, in parallel, the reconversion of these into crystalline species that can be used in other technological fields. The potential of a ubiquitous microorganism, Penicillium sp. 8L2, to retain Cu(II) ions was investigated, as well as the ability of its cellular extract to synthesize CuO nanoparticles, which were subsequently evaluated as biocidal agents against five microorganisms. A response surface methodology was used to determine the optimal operating conditions of the biosorption process, setting the pH at 4.8 and the biomass concentration at 0.8 g/L and obtaining a maximum biosorption capacity at equilibrium of 25.79 mg/g for the Langmuir model. Different analytical techniques were used to study the biosorption mechanisms, which revealed the presence of surface adsorption and intracellular bioaccumulation phenomena involving different functional groups. The fungal cell extract allowed the successful synthesis of CuO-NPs with an average size of 22 nm. The biocidal tests performed with the nanoparticles showed promising values of minimum inhibitory concentrations between 62.5 and 500 µg/mL. Penicillium sp. 8L2 showed good potential for its application in the field of heavy metal bioremediation and for the green synthesis of nanoparticles useful in biomedicine.

The application of artificial neural network (ANN) to validate biosorption of Zn+2 ions onto chemically modified Hevea brasiliensis sawdust

The study examined the biosorption of Zn+2 by chemically modified Hevea brasiliensis sawdust using a batch adsorption system. The influence of concentration, pH, contact time, and adsorbent dose in a batch biosorption process were analyzed and the maximum Zn+2 uptake capacity was found as 36.8 mg/g. The Langmuir and Temkin model was found to be the most accurate when the experimental data were analyzed using the different adsorption isotherms models. This study presents an experimental modeling approach for the biosorption process based on artificial neural networks (ANN). Data from biosorption experiments were utilized to train and validate the ANN model. The ANN model can effectively represent the biosorption process, as demonstrated by the significant correlation (R 2 = 0.998) established between the model and experimental data. A kinetic study revealed that the Zn+2 biosorption was favored by the pseudo-first-order and pseudo-second-order models. The process is feasible, spontaneous, and endothermic, according to thermodynamic study. The H. brasiliensis sawdust underwent chemical carbonization, and its characteristics were examined using energy EDX, BET surface area analyzer, SEM, XRD, and FTIR.

Eliminating aqueous effluents with low-cost bioadsorbents: adsorbent characterization and mechanistic removal studies

This study focused on the synthesis and preparation of cationic and anionic biomaterials. These materials were used as adsorbents in waters polluted by various adsorbates likely to be present in the environment. Using a batch adsorption approach, this work interprets biomass Pumpkin Seed Shells (PS) as an inexpensive, environmentally benign, and promising adsorbent for 4-nitrophenol (4NP) adsorption from aqueous solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer Emmett Teller (BET) spectroscopy were among the methods used to characterize the produced biosorbent. Batch experiments were conducted based on various process factors, such as temperature, pH, concentration, contact time, and material dose. Very excellent results were obtained with a pH of 6.5, a biosorbent dosage of 0.030 g, an initial 4-nitrophenol concentration of 30 mg/L, and a temperature of 25°C.and 298 K, which were ideal for removing 4NP. 97.95% sorption was the maximum. Adsorption data better fit the Freundlich, Temkin, Liu, and Langmuir isotherms. It was demonstrated that the biosorption process is spontaneous and exothermic and that the rate of sorption obeys the Elovich and pseudo-second-order kinetics.This article explains how to create inexpensive, environmentally friendly adsorbents and looks at how well they can remove 4-nitrophenol from wastewater. The unaltered biochar-based pumpkin seed shells were characterized using basic analysis, FTIR, SEM, and BET.

Identification of cadmium-tolerant plant growth-promoting rhizobacteria and characterization of its Cd-biosorption and strengthening effect on phytoremediation: Development of a new amphibious-biocleaner for Cd-contaminated site

The use of plant growth-promoting rhizobacteria (PGPR) in decontaminating cadmium-contaminated soil and water is a sustainable and eco-friendly approach. This study aimed to isolate a PGPR strain from the rhizosphere soil of Solanum nigrum and evaluate its potential and mechanisms in remediating Cd-contaminated environments. The results showed that the isolated strain, Klebsiella sp. AW2, can tolerate 240mg/L Cd2+. Batch biosorption experiments indicated that the optimal conditions for PGPR biosorption were a pH of 5.0, a biosorbent dosage of 1.0g/L, and a Cd2+ concentration of 10mg/L, resulting in a biosorption rate of 40.99%. Model fitting results revealed that the Cd biosorption process followed a uniform surface monolayer chemisorption mechanism, likely involving complexation with functional groups such as -NH, -OH, and -C=O, according to Fourier transform infrared spectrometer and desorption experiments. Furthermore, pot experiments demonstrated that PGPR application significantly enhanced the phytoremediation efficiency of Cd-contaminated soil, increasing the phytoextraction ratio by 32.41%. This improvement was primarily achieved by promoting S. nigrum growth and facilitating Cd horizontal transfer from rhizosphere soil to plants through influencing the rhizosphere soil physicochemical properties and Cd2+ influx in roots. In addition, the copy number of the 16S rRNA gene of the PGPR revealed that the PGPR was predominantly localized in the rhizosphere soil, directly leading to increased availability of Cd for plant uptake. Overall, these findings indicate that Klebsiella sp. AW2 is a promising biocleaner for Cd-contaminated environments and provide valuable insights into the application of biosorbents in phytoremediation efforts.

Effect of Blue Light Color on Zn (II) and Cu (II) Metal Biosorption Using Tetraselmis chuii Microalgae

Direct release of inorganic compounds Cu (II) and Zn (II) into water bodies can disrupt ecosystems. Using microalgae biosorbent Tetraselmis chuii (T. chuii) is a promising approach for removing these metals from wastewater. This study investigated the effect of blue light on the absorption of Cu (II) and Zn (II) by analyzing the contact time and initial concentration. Statistical analysis (MANOVA) revealed differences in the biosorption process due to the contact time and Cu (II) concentration (P <0.05). The results showed that the most effective Cu (II) removal occurred with a 60-minute contact time at a concentration of 5 mg/L, achieving a 67.07% removal rate. Zn (II) removal was also efficient under blue light conditions with a 60-minute contact time at the same concentration, yielding a 56.23% removal rate. Additionally, this process led to a substantial reduction in microalgae T. chuii cell density, by 76% for Cu (II) and 89.2% for Zn(II). Characterization analyses using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy confirmed the presence of functional groups in T. chuii microalgae, which are crucial for the biosorption process. This study underscores the potential of microalgae as effective biosorbents for mitigating inorganic compound pollution in wastewater.

Eco-efficient cadmium(II) removal from water using alcohol distillate waste: A study of life cycle assessment

Eco-efficient cadmium(II) removal from water using alcohol distillate waste: A study of life cycle assessment

Uptake of lead, cadmium and copper by heavy metal-resistant Pseudomonas aeruginosa strain DR7 isolated from soil.

This study highlights the biosorption capacity for Cd (II), Cu (II) and Pb (II) by a locally isolated Pseudomonas aeruginosa DR7. At initial concentrations of 150mg L-1 and 240min of contact time, P. aeruginosa DR7 showed a 62.56mg/g removal capacity for Cd (II) at an optimum pH of 6.0, 72.49mg/g for Cu (II) at an optimum pH of 6.0, and 94.2mg/g for Pb (II) at an optimum pH of 7.0. The experimental data of Cd (II), Cu (II), and Pb (II) adsorbed by the pseudo-second-order kinetic model correlates well with P. aeruginosa DR7, with R2 all above 0.99, showing that the fitting effect was satisfactory. The isothermal adsorption processes of Cd (II) (0.980) and Cu (II) (0.986) were more consistent with the Freundlich model, whereas Pb (II) was more consistent with the Langmuir model (0.978). FTIR analysis suggested the involvement of hydroxyl, carbonyl, carboxyl, and amine groups present in the inner regions of P. aeruginosa cells during the biosorption process. SEM-EDS analysis revealed that after contact with metals, there were slight changes in the surface appearance of the cells, which confirmed the deposition of metals on the bacterial surface. There was also the possibility of the metals being translocated into the bacterial inner regions by the appearance of electron-dense particles, as observed using TEM. As a conclusion, the removal of metals from solutions using P. aeruginosa DR7 was a plausible alternative as a safe, cheap, and easily used biosorbent.

Biosorption of cypermethrin from aqueous solutions by Pediococcus acidilactici: kinetics, isotherms, and mechanisms.

Pediococcus acidilactici is an effective adsorbent for removing of pyrethroid insecticides. This study investigated the biosorption characteristics and mechanisms of P. acidilactici D15 using adsorption measurement, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Isotherm and kinetic models were used to analyze the biosorption process. The Langmuir isotherm model best described the cypermethrin biosorption process, with the maximum adsorption capacity of P. acidilactici D15 being 21.404 mg/g. The biosorption appeared to involve monolayer coverage with uniform forces. The pseudo-second-order model also fits well. The rate-controlling steps involved intraparticle diffusion, film diffusion and chemosorption. The main cellular components involved in cypermethrin biosorption were exopolysaccharides, spheroplast, and cell wall, especially peptidoglycan. The functional groups (-OH, -NH, -CH3, -CH2, -CH, -CONH-, -CO, and -C-O-C-) from proteins, polysaccharides, and peptidoglycan on the cell surface likely played a role in binding cypermethrin. Additionally, P. acidilactici D15 effectively reduced cypermethrin in pickle wastewater. These findings suggest that P. acidilactici D15 could be a potential agent for reducing pesticide residues, laying the groundwork for treating pickle wastewater containing such pesticide residues. © 2024 Society of Chemical Industry.

Comparison of biocrude production and characterization from Persian Gulf Sargassum angustifolium macroalgae, Chlorella vulgaris, and Spirulina sp. microalgae using hydrothermal liquefaction (HTL): Potential of solid residue for heavy metal adsorption.

Biocrude production using the hydrothermal liquefaction (HTL) process is a promising alternative energy source to conventional fossil fuels. Using algal feedstock types in this process has many advantages, such as not needing to dry a high moisture content, which consumes much energy. In this study, the feedstock types of Sargassum angustifolium macroalgae, Chlorella vulgaris, and Spirulina sp. microalgae affected the yield and property of the biocrude products were obtained at 350 °C, 18 MPa, 35 min residence time, and 8.7 wt% feedstock concentration. The biocrude yields from Sargassum angustifolium, Chlorella vulgaris, and Spirulina sp. were 26.15 wt%, 55.8 wt%, and 56.32 wt%, respectively. These values revealed that feedstock's carbon and nitrogen contents have the most effect on the biocrude yield, and increasing these elements increases the biocrude yields. Moreover, the properties of the produced biocrudes revealed that the main components were esters, organic acids, ketones, aldehydes, aromatic rings, amides, amines, alcohol, and phenol. The thermal gravimetric analysis (TGA) results of biocrudes showed the decomposition of more organic components at the 175-600 °C temperature range. Also, the simulated distillation of biocrudes showed that most biocrude components from Sargassum angustifolium and Chlorella vulgaris are the same as heavy naphtha, and the biocrude from Spirulina sp. is similar to kerosene. These results showed that the produced biocrude from Chlorella vulgaris has a higher yield and quality than other resources. The quality of the biocrude produced from Sargassum angustifolium is comparable to other biocrudes. Besides, the higher solid-phase yield produced from Sargassum angustifolium was used as a heavy metal biosorbent. The effect of adsorbent concentration and adsorption time on adsorption efficiency was investigated. Results showed that the maximum adsorption efficiency of Fe2+, Zn2+, and Mn2+ was 47.07 wt%, 48.93 wt%, and 42.47 wt%, respectively, at 2 g/L adsorbent concentration and 60 min adsorption time, and the structure destruction of the solid phase was carried out under the biosorption process.