Addition Of Biosurfactant Research Articles

Effect of surfactant type and concentration on the gas-liquid mass transfer in biotrickling filters used for air pollution control

Volatile organic compounds (VOCs) emitted into the atmosphere negatively affect the environment and human health. Biotrickling filtration, an effective technology for treating VOC-laden waste gases, faces challenges in removing hydrophobic VOCs due to their low water solubility and therefore limited bioavailability to microorganisms. Consequently, the addition of (bio)surfactants has proven to be a promising strategy to enhance the removal of hydrophobic VOCs in biotrickling filters (BTFs). Yet, up to now, no single study has ever performed a mass transfer characterization of a BTF under (bio)surfactants addition. In this study, the effect of (bio)surfactant addition on the gas-liquid mass transfer characteristics of two BTFs was measured by using oxygen (O2) as a model gas. Through an empirical correlation, the mass transfer coefficients (kLa) of two hydrophobic VOCs, toluene and hexane, which are of industrial and environmental significance, were estimated. One BTF was filled with expanded perlite, while the other with a mixture of compost and wood chips (C + WC). Both BTFs were operated under different liquid velocities (UL: 0.95 and 1.53 m h−1). Saponin, a biological surfactant, and Tween 80, a synthetic surfactant, were added to the recirculating liquid at different critical micelle concentrations (CMCs: 0–3 CMC). The higher interfacial and surface area of the perlite BTF compared to the C + WC BTF led to higher kLaO2 values regardless of the operational condition: 308 ± 18–612 ± 19 h−1 versus 42 ± 4–177 ± 24 h−1, respectively. Saponin addition at 0.5 and 1 CMC had positive effects on the perlite BTF, with kLaO2 values two times higher compared to those at 0 CMC. Tween 80 exhibited a neutral or slightly positive effect on the mass transfer of both BTFs under all conditions. Overall, the CMC, along with the physical characteristics of the packing materials and the operational conditions evaluated explained the results obtained. This study provides fundamental data essential to improve the performance and design of BTFs for hydrophobic VOCs abatement.

The Study of Biosurfactant Stability and The Effect on Lipase Activity

Lipase is one of hydrolase enzyme that catalyzed hydrolysis reaction of triacylglycerols into free fatty acids and monoglycerides or glycerol. These biocatalysts are widely used in several industries, namely food and pharmaceutical industry. The activity of lipase can increase significantly if the substrate forms an emulsion. Since biosurfactant has been known to have emulsification characteristic, the effect of biosurfactant addition into lipase is necessary to be investigated. It is the first report that evaluate the effect of microbial surfactant on lipase activity. The purpose of this research is to analyze the stability of biosurfactant emulsion under various conditions, such as salinity and pH as well as their potential to enhance lipase activity. Biosurfactant used was Halomonas elongata BK-AG18 from the collection of Biochemistry Research Group ITB, Bandung, Indonesia. It was found that after the addition of NaCl, there was no significant decrease in the emulsification activity of the biosurfactant. The emulsification index (IE24) of biosurfactant with several NaCl concentrations (2, 5, 10, 15, 20, and 25%) was obtained around 50%. Stability test of biosurfactant at pH range 4-10 showed the highest IE24 of biosurfactant was obtained at pH 6. The effect of biosurfactants on lipase hydrolysis activity is also discussed in this article. Lipase hydrolysis activity was tested using p-nitrophenyl palmitate substrate. The highest lipase activity was obtained after the addition of 70% biosurfactant (v/v) at 0.026 units. This study shows that biosurfactant from H. elongata BK-AG18 has the potential to increase lipase activity.

Enhanced Removal of Hydrocarbons from Crude Oil Sludge through Phytoremediation with Biosurfactant-producing Rhizobacteria

Discharge of crude oil (or its products) during the extracting, refining, and transporting into the environment have caused serious environmental distress due to their highly hydrophobic resistance, and persistence in nature and very difficult to be remediated from the environment. Therefore, an environmentally conscious approach to enhance the bioavailability (or solubility) of petroleum hydrocarbon pollutants in soil involves the utilization of biosurfactants. Biosurfactants play a crucial role in enhancing the desorption and solubilization of petroleum hydrocarbons, facilitating their assimilation by microorganisms. This research investigated the application of biosurfactant supplementation derived and purified from rhizobacteria of Scirpus grossus, which are capable of producing biosurfactants and degrading hydrocarbons, in the context of phytoremediation. The crude oil sludge used in this study was obtained from an industrial area containing 56,600±3;900 mg/kg of total petroleum hydrocarbon (TPH). The crude oil sludge was inoculated with biosurfactant, sodium dodecyl sulfate (SDS) as commercial surfactant and only with the presence of S. grossus in the vegetated tanks and monitored for 90 days in a greenhouse. The results indicated that the growth of S. grossus with the addition of biosurfactant was improved and new saplings were produced. After a 90-day exposure period, the removal efficiency of TPH from the soil demonstrated significant increases, reaching 90.3%, 84.1%, and 73.7% when treated with biosurfactant+S. grossus, SDS+S. grossus, and S. grossus only respectively. These percentages were notably higher compared to the non-planted control crates (CC) where the removal efficiency was only 17.9%. These results provide evidence that the introduction of biosurfactant through inoculation can elevate the bioavailability of organic pollutants, consequently augmenting their microbial degradation in the soil.

The potency of spores and biosurfactant of Bacillus clausii as a new biobased sol-gel coatings for corrosion protection of carbon steel ST 37 in water cooling systems

The structures of water cooling systems are prone to microbially-influenced corrosion (MIC) due to the favorable conditions for microbial growth. Biofilm formation accelerates corrosion, leading to reduced system efficiency, structural damage, and significant financial losses. Encapsulating viable bacterial spores and biosurfactant within a silica-based sol-gel coating offers an eco-friendly approach to prevent this type of corrosion. Bacillus clausii, known for its antimicrobial biosurfactant production capability, was utilized in this study to investigate the impact of spores and biosurfactant addition to silica-based sol-gel coatings in inhibiting biofilm formation and preventing corrosion in water cooling systems. Microbiological analysis of the biofilm was conducted using the total plate count method, while the corrosion process was analyzed through electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The viability of B. clausii spores within the sol-gel matrix was determined to be 20.8 %. The presence of bacterial spores and biosurfactant significantly increased the hydrophobicity of the sol-gel coating. Incorporating spores within the sol-gel matrix delayed biofilm formation for up to 12 days, while biosurfactant addition showed the smallest biofilm abundance (2.23×105 CFU/mL) at its maturation phase compare to others. After 180 days of incubation, analysis of Bode and Tafel plots demonstrated that the sol-gel coating containing biosurfactant maintained excellent anti-corrosion performance, exhibiting an impedance of 104 Ω cm2, Ecorr of -0.398 V vs SCE, and icorr of 0.51 µA/cm2. SEM-EDS analysis of the surface sample revealed a comparably smooth and uniform surface with a minimal abundance of exposed Fe atoms at 0.12 %. In conclusion, this study demonstrated the high potency of the sol-gel coating supplemented with biosurfactant in inhibiting biofilm formation and corrosion on metals in water cooling systems.

Efficient and eco-friendly mixed bacterial consortium for petroleum wastewater treatment: Effect of the bio-augmentation and biosurfactant addition on hydrocarbon biodegradation

In the present investigation, we aimed to study biological petroleum wastewater treatment. A bioprocess based on the use of a mixed bacterial consortium along with the addition of Biosurfactant (BioS) and bioaugmentation with BioS producing strains were evaluated. The consortium was the combination of two bacterial strains with the capacity to metabolize hydrocarbons, Baci and B201. Two other strains BH1 and BSS2 selected for their ability to degrade hydrocarbons as well as to produce BioS were also exploited. The effect of ex-situ and in-situ produced BioS on hydrocarbon biodegradation were compared. Obtained results demonstrated a moderate capacity to remove crude oil from contaminated water of about 47% for the consortium. The best improvement of hydrocarbon biodegradation of about 84% was obtained when adding BH1 derived BioS solely. However, ex-situ produced BioS exhibited better results. Regarding the wastewater characteristics, we note a decrease of the COD/BOD5 Ratio to reach 2.64. Thus, the wastewater became easily biodegradable. The described bioprocess is of great interest for the bioremediation of petroleum effluents. BioS addition as well as bioaugmentation enhanced crude oil removal.

Pulse galvanostatic electrodeposition of biosurfactant assisted brushite-hydroxyapatite coatings on 316 L stainless steel with enhanced electrochemical and biological properties

In this study, a novel microbial green surfactant (lipopeptide surfactin) was utilized to facilitate the pulse electrodeposition of brushite (CaHPO4·H2O) and hydroxyapatite (Ca10(PO4)6(OH)2) coatings on stainless steel (316 L SS). The addition of the biosurfactant and change in the current density (CD) affect the coating composition and its structural morphology. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were performed to analyse the composition of the coatings. Without biosurfactant addition, the brushite phase is prevalent in the coatings with a minor content of hydroxyapatite. However, in the coatings deposited with biosurfactant as an additive, only the brushite phase is prominent suggesting that the biosurfactant inhibits the growth of the hydroxyapatite phase. Scanning electron microscopy (SEM) analysis reveals well-defined flower-like morphology for biosurfactant-assisted coatings, while the other coatings show a broom-like morphology. The addition of biosurfactant reduces the crystallite size along with the increased surface roughness and adhesion strength of the coatings. The cytocompatibility of the developed coating was assessed using the MTT assay with fibroblast cells (L929). Further, the cell adhesion, morphology the of cell and cell-coating interactions were evaluated using SEM. The corrosion resistance, in vitro degradation, antibacterial, antioxidant and antibiofouling properties, and hemocompatibility are improved due to the addition of biosurfactant to the electrolytic solution. Collectively, these results imply that the biosurfactant-aided brushite-coated surfaces can be used for bone regeneration, tissue engineering and biomedical applications.

Optimization of textile effluent bacterial treatment and improvement of the process efficiency through SPB1 biosurfactant addition.

The current work aims to optimize biological textile effluent treatment through the use of newly selected bacterial consortia composed of two strains: Citrobacter sedlakii RI11 and Aeromonas veronii GRI. We assessed the effect of SPB1 biosurfactant addition on color removal (CR). The process was optimized by a Box-Bhenken by examining the effect of pH, consortia density and biosurfactant value on treatment efficiency. Firstly, physicochemical analyses of the studied effluent revealed an alkaline pH along with a high content of suspended materials and large amounts of organic matter. Optimal CR and a chemical oxygen demand abatement of about 94 and 86% were obtained when treating the textile effluent at pH 5 with a total optical density of 0.4 and by incorporating 0.01% SPB1 biosurfactant. Additionally, an abolishment of phytotoxicity was registered after treatment optimization. The evaluations of the action mode of both selected bacteria during textile effluent treatment suggested the occurrence of biodegradation phenomena of dyes through enzymatic activities.

Enhancing Biodegradation of Pyridine with Trehalose Lipid in Rhodococcus pyridinivorans sp. Strain HR-1-Inoculated Microbial Fuel Cell

A Gram-positive exoelectrogen Rhodococcus pyridinivorans sp. strain HR-1 was cultivated from leachate-fed microbial fuel cell (MFC) to study the biodegradation effect of pyridine. In the comparison with mixed cultured MFC, HR-1 presented a remarkable electrical capacity with a maximum output of 4.33 W/m3 under 30 °C in neutral anolyte with 1 g/L acetate as a substrate. Further, HR-1 demonstrated the environmental resistance as a Gram-positive strain. Microbial metabolism was evident at pH between 5–9 and temperature in the range of 20–40 °C, whereas optimal condition for pyridine degradation was observed at 30 °C. This is the first study reporting the degradation of pyridine in the bio-electrochemical system that achieved a 42% ± 5% degradation rate in a full operation cycle at 2 g/L of the concentration. Considering the nonnegligible internal resistance of HR-1-inoculated MFC, trehalose lipid was also introduced as a bio-surfactant to reduce the charge transfer obstacle between the microbes and the electrodes. The surface morphology illustrated that the strain had a plump shape with a high specific area. Accordingly, bio-surfactant addition promoted the anode biomass (1.2 ± 0.1 mg/cm2 to 1.7 ± 0.2 mg/cm2) and achieved a higher degradation rate (68% ± 4%). The feasibility of electrochemical disposal on pyridine and eminent adaptability of strain sp. HR-1 as a Gram-positive exoelectrogen makes MFC a practical approach for real application.

Decolorization of methyl red using Bacillus thuringiensis RI16 strain: Enhanced bacterial treatment by SPB1 biosurfactant addition

Abstract In this work, we evaluate the ability of a novel isolated bacteria identified as Bacillus thuringiensis RI16 (KM111604) to decolorize methyl red. Results showed its efficiency for the treatment of azo-dye-contaminated wastewaters under static conditions at pH values ranging from 7 to 9. The isolated bacteria could tolerate higher doses of dyes as it was able to decolorize up to 1000 mg/L. For better methyl red decolorization, we evaluate the potential use of Bacillus subtilis SPB1-derived lipopeptide biosurfactant. The study showed its ability to accelerate the decolorization rate and slightly maximized the decolorization efficiency at an optimal concentration of 0.025%. Compared with synthetic surfactants, the bacterial surfactant was more efficient as we observe a drastic decrease and an inhibition of methyl red decolorization by cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) additions. Also, studies ensured that methyl red removal by this strain could be due to extracellular enzymatic activities. SPB1 biosurfactant could improve enzyme activities and/or enzyme synthesis and diffusion.

Effects of regular addition and discontinuation of biosurfactant on hydrocarbon biodegradation and microorganisms in heavy oily sludge

Effects of regular addition and discontinuation of biosurfactant on hydrocarbon biodegradation and microorganisms in heavy oily sludge

Potential Application of Biosurfactant-Producing Bacteria for Bioremediation of Oil Polluted Marine Intertidal Sediments

The removal of oil contaminants in marine intertidal sediments under cold climate is an urgent issue. Although the bioavailability of petroleum hydrocarbons decreases at low temperatures, biosurfactants can promote oil biodegradation. In this study, characteristics of biosurfactants produced by cold-adapted oil-degrading bacteria Planococcus sp. XW-1 were studied. Adding the XW-1 biosurfactant could effectively facilitate the solubility of phenanthrene, pyrene, diesel oil, and crude oil. The solubilization was limited by the number of rings and the molecular weight (WSRphenanthrene = 0.0234; WSRpyrene = 0.0165; WSRdiesel oil = 0.0027; WSRcrude oil = 0.0015). Additional biosurfactants significantly washed out crude oil adsorbed to the sand (reduction from 17.1%, 22.7% to 87.9% and 94.28% in 24 h). With the increase in particle size, the removal efficiency increased from 87.9% to 94.28%. After the addition of biosurfactant, the effect of degradation increased by 20% in 20 days. The results suggest that the biosurfactant-producing bacteria Planococcus sp. XW-1 is a promising candidate used in the in situ bioremediation of petroleum-contaminated intertidal sediment.

Impact of biosurfactant and iron nanoparticles on biodegradation of polyaromatic hydrocarbons (PAHs)

Polycyclic aromatic hydrocarbons (PAHs) are hazardous toxic contaminants and considered as primary pollutants due to their persistent nature and most of them are carcinogenic and mutagenic. The key challenge in PAHs degradation is their hydrophobic nature, which makes them one of the most complex materials and inaccessible by a broad range of microorganisms. This bioavailability can be increased by using a biosurfactant. In the present study mixed PAHs were degraded using the biosurfactant producing bacterial strains. In addition, iron nanoparticles were synthesized and the impact of iron nanoparticles on the growth of the mixed bacterial strains (Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3) was optimized. The mixed PAHs (anthracene, pyrene, and benzo(a)pyrene) degradation was enhanced by addition of biosurfactant (produced by Bacillus subtilis A1) and iron nanoparticles, resulting in 85% of degradation efficiency. The addition of the biosurfactant increased the bioavailability of the PAHs in the aqueous environment, which might help bacterial cells for the initial settlement and development. The addition of iron nanoparticles increased both bacterial biomass and PAHs adsorption over their surface. These overall interactions assisted in the utilization of PAHs by the mixed bacterial consortia. This study illustrates that this integrated approach can be elaborated for the removal of the complex PAHs pollutants from soil and aqueous environments.

Optimization of conditions for a surfactant-producing strain and application to petroleum hydrocarbon-contaminated soil bioremediation

Petroleum hydrocarbon-contaminated sites have been mainly remediated through the surfactant-enhanced soil leaching method. However, the commonly used chemical surfactants have poor biocompatibility and are prone to form residues in fields. Therefore, the purpose of this research is to establish an effective system of biosurfactant remediation in the field and provide instructions for common bioremediation challenges. First, wild-type Bacillus amyloliquefaciens A3, which produced lipopeptide biosurfactant, was used to improve the production of biosurfactant by atmosphere and room temperature plasma (ARTP) mutagenesis. Second, the mutant 1–24 was selected from a total of 174 mutants due to the outstanding yield. Subsequently, 1–24 was applied in the soil column leaching experiments and removed 45.44% of petroleum hydrocarbons by changing the relevant enzyme activities. Biosurfactant addition and 1–24 inoculation effectively activated a portion of the petroleum hydrocarbons in the soil columns, and 1–24 presented potential as a desired candidate for bioremediation. This is the first report of using ARTP mutagenesis to improve the production of biosurfactants. Simultaneously, we first propose a theoretical system in which the yield of biosurfactant was increased using ARTP mutagenesis for strains and applied the mutants in situ soil bioremediation. This research indicated that the theoretical system was useful in soil columns to simulate field remediation conditions, providing practical references for the bioremediation of contaminated soil.

Assessment of antibacterial properties of electrospun fish collagen/poly (vinyl) alcohol nanofibers with biosurfactant rhamnolipid

The emulsion electrospinning has gained interest in the fabrication of collagen-poly (vinyl) alcohol (PVA) nanofiber scaffold as it enables the production of a non-woven fibrous membrane with a similar organization of extracellular matrix. Fish collagen (FC) along with poly (vinyl) alcohol and rhamnolipids (biosurfactant) was utilized to produce beadless and smooth nanofiber mat. Rhamnolipid biosurfactants were incorporated into FC-PVA polymer solution and fabricated through emulsion electrospinning. The influence of biosurfactants on the physical and morphological features of nanofiber mat was characterized by FT-IR, XRD, UTM, TGA-DSC, and FE-SEM. The addition of biosurfactant on nanofiber results in the enhancement of the spin ability, stability towards degradation, and reduction in the diameter of the fiber (254.89 ± 6.42 nm) with high conductivity (14.43 ± 2.45 mS/cm) of a polymer solution. The incorporation of biosurfactant rhamnolipid into the polymer mixture of FC-PVA enhanced its antibacterial properties to 63.23 ± 3.23% in the case of E.coli ATCC-25922 and 57.32 ± 4.19% towards B.cereus ATCC-11778. Hence by the addition of biosurfactant rhamnolipid in an emulsion, a fiber diameter was reduced without ant beads in it and leads to the enhancement of the bactericidal properties of electrospun nanofiber mat.

An experimental design approach investigating the effects of operating variables on the viscosity of heavy crude oil-in-water emulsions using lecithin as a natural surfactant

This work investigates the effects of the addition of biosurfactant (lecithin) for the reduction of heavy crude-oil viscosity. Response surface methodology was employed to study the effect of three experimental factors: temperature, water to oil ratio (WOR) and emulsifier concentration (EC). All factors were found to have a high significant effect on the viscosity of the heavy crude oil. The interaction between temperature and WOR had more impact compared to that between WOR and EC. Yet the interaction between temperature and EC was not significant. Moreover, lecithin concentration seemed to have more effect on the viscosity reduction at low WOR. A model was developed for the viscosity with respect to the investigated factors and proved its goodness of fit with R2 of 96.03% at 95% confidence level. A good agreement between predicted and experimental values was achieved. The optimum conditions for achieving a targeted viscosity value based on industrial recommendations were determined and experimentally verified.

Field Test of U-Champ Biosurfactant in Oil Spill Bioremediation

One of the serious environmental problems of the oil and gas industry is handling oil spills. Oil spills can be managed by using bioremediation in the form of biosurfactants. In this research, biosurfactants called U-Champ were used which can impact in remediation of oil spills. The research conducted was testing the effectiveness of biosurfactants on Cepu Field contaminated soil in reducing TPH and heavy metals. The method is done by stirring the contaminated soil with various concentrations of biosurfactant product in an artificial tank. Based on the test results, a decline in TPH and TCLP along with the increase in U-Champ biosurfactant concentration was used. The addition of 6 Liters of biosurfactant gave the most significant reduction. Some of the heavy metals in the soil decrease, but some also have increased. As an example, it can be seen in Ba metal, the addition of U-Champ biosurfactant as much as 1.5 L (0.3% v / v) resulted in a decrease in TCLP of 11.085%. The qualitative result is evidenced by the growth of various plants in each artificial tank.

Role of surfactant in affecting photo-fermentative bio-hydrogen production performance from corncob

Surfactant addition can cause a significant change in the interface state of the solution system, which is helpful to avoid agglomeration and sedimentation of solid state, and improve the mass transfer capacity. Hence, the performance of high-solid photo-fermentative bio-hydrogen production system with bio-surfactant addition was evaluated in this work. Corncob was selected as raw material, and cumulative hydrogen yield (CHY) was taken as reference. The effect of Rhamnolipids (RLs) and Tea Saponin (TSn) addition on hydrogen yield capacity was investigated. The results showed that CHY was effectively increased by the addition of RLs and TSn, the highest CHY of 356.42 ± 16.5 mL and 265.38 ± 7.5 mL appeared when the concentrations of surfactant addition were 0.08 g/L RLs and 1.5 g/L TSn, which were 67.85% and 24.97% higher than control group, respectively. The maximum energy conversion efficiency reached 5.47% and 4.08% with an increase of 67.8% and 25.2%.

Optimization Approach for Solvent Extraction Process of Oily Contaminated Soil with Addition of Biosurfactant

Objectives : Solvent extraction is a process in which not only enable to reduce oil contaminant from soil residue, but also capable to recover oil from soil matrix of oily contaminated soil which has opportunity to be reutilized. Optimization process has been simulated by previous studies related to type and dosage of solvents, variances of temperature, additional of surfactants, and other related parameters to increase oil removal from oily contaminated soil. This study seeks an approach of optimization for solvent extraction process to oily contaminated solid waste by conducting statistical analysis into laboratory experimentation from perspective of Total Petroleum Hydrocarbon (TPH) removal.Method : Biosurfactant became single extractors for multistage extraction process and also combined with other solvents which are acetone and toluene. Mixing method that utilized during the study was combination between horizontal shaking at 150 rpm in 15 min duration and centrifugation force at 1,570 g in 10 min duration. Statistical analysis were conducted to seek its multiple regression.Result : Study describing biosurfactant performance single extractor by using multistage extraction process achieve 77% TPH removal, while combination of biosurfactant and solvent extraction by using toluene and acetone also capable to increase TPH removal 7% higher from original performance of both toluene and acetone at solvent extraction.Conclusion : Surfactant and solvents combination is promising to improve TPH removal, while statistics analysis that implemented to observed extraction process has possibility to be used for engineering higher efficiency of extraction process.

Screening and Optimization of Carbon Source to Increase High Thermostabile Biosurfactant Production for Microbial Enhanced Oil Recovery (MEOR) Application

Petroleum, is by far, one of the world’s major energy sources. However, its production continues to decline every year. One of the effort developed to increase crude oil production is biosurfactant addition. This research aimed to optimize carbon source as substrate used to produce bacterial biosurfactant. The first stage of the study was carbon source screening with based on biosurfactant’s dry weight, IFT value, and emulsification index parameters. The carbon source candidates were crude oil, glucose, molasses, and palm oil mil effluent (POME). Screening stage of crude oil, glucose, molasses, and POME resulted in (a) biosurfactant yield of 0.58, 3.18, 1.47, and 1.38 g/L; (b) IFT decrease of 6.9, 7.7, 4.6, and 6.1 dyne/cm; and (c) emulsification index of 62.5, 72.5, 47.5, and 58.75% for respective treatments. POME was chosen as the best carbon source in consideration that it was readily available in large quantities and lower cost compared to crude oil, glucose, and molasses. Treatments of 1, 3, 5, and 7% POME treatment yielded biosurfactant in the concentrations of 1.08, 1.28, 0.7, and 0.98% g/L respectively. Treatment of 3% POME was chosen as the best concentration to stimulate biosurfactant production. Biosurfactant produced was subsequently applied to sand-pack column simulation and additional oil recovery (AOR) of 20-40% was obtained. Functional group characterization using FTIR showed that biosurfactant produced in this study belonged to lipopeptide group.

Statistical analyses of the effect of rhamnolipid biosurfactant addition on the enzymatic removal of Bisphenol A from wastewater

Abstract Bisphenol A (BPA), a major phenolic pollutant, is hazardous, toxic, and mutagenic. Although there are some chemical and physical processes to treat wastewater polluted with BPA, most of these methods are either costly or detrimental to the environment (i.e., generate serious secondary pollution). Unlike chemical and physical treatment methods, enzymatic treatment is environmentally friendly, more selective towards the targeted phenolic pollutant(s) and uses sustainably produced materials (i.e., enzymes). In this work, a clean process based on enzyme (i.e., laccase) and biosurfactant (i.e., rhamnolipid) is developed in order to study the removal of BPA from wastewater. Several statistical analyses of the effect of rhamnolipid (RL) addition on the enzymatic removal of BPA under different process conditions have been performed. The results revealed a positive correlation between RL addition and BPA removal irrespective of the initial BPA concentration, reaction time, reaction temperature, pH of the reaction medium, and wastewater salinity. The statistical analyses also revealed that the two-way interactions between RL addition and reaction time and between RL addition and the initial BPA concentration are significant. However, the two-way interactions between RL addition and the reaction temperature, RL addition and the pH of the reaction medium, and RL addition and the wastewater salinity are insignificant, unlike the significant effects of the individual factors.