Development and testing of "Ekosorb" biosorbent based on association of petroleum-oxidizing bacteria for purifying petroleum-polluted soils

A biosorbent containing an association of oil-oxidizing bacteria as a main constituent was developed, in which Lessorb, a product of moss and wood thermal processing, was used as a carrier. Xeroprotectors preserving the cell viability and oil-oxidizing activity in the biosorbent on drying and after long-term storage were selected. The use of this biosorbent for cleaning oil-polluted sod-podzol soils showed a two-threefold cleanup rate acceleration at different pollution levels (8 and 24 l/m2), especially in the presence of a nitrogen-phosphate fertilizer. The biosorbent increased the populations of certain groups of soil microorganisms and the total soil biological activity.     

Creation and use of a liquid substance based on association of petroleum-oxidizing bacteria

An association of four bacterial strains with high oil-oxidizing and bioemulsifying activities, psychrophilicity, resistance to chemical pollutants, and lack of pathogenicity was selected from a collection of natural oil-oxidizing microorganisms. A new liquid preparation containing stabilizers and preservatives that maintain the cell viability and oil-oxidizing activity during long-term storage was developed. A field experiment in oil-polluted sod-podzol and clay sand soils demonstrated that this preparation accelerated the biodegradation of oil and its individual fractions, especially in the presence of mineral and organic fertilizers. Treatment of oil-polluted soil with this preparation and additives decreased the oil-induced suppression of certain groups of soil microflora.     

Development and Application of a Liquid Preparation with Oil-Oxidizing Bacteria

An association of four bacterial strains with high oil-oxidizing and bioemulsifying activities, psychrophilicity, resistance to chemical pollutants, and lack of pathogenicity was selected from a collection of natural oil-oxidizing microorganisms. A new liquid preparation containing stabilizers and preservatives that maintain cell viability and oil-oxidizing activity during long-term storage was developed. A field experiment in oil-polluted sod-podzol and clay sand soils demonstrated that this preparation accelerated the biodegradation of oil and its individual fractions, especially in the presence of mineral and organic fertilizers. Treatment of oil-polluted soil with this preparation and additives decreased the oil-induced suppression of certain groups of soil microflora.     

Purification of soil from oil pollutants with the use of denitrifying hydrocarbon-oxidizing microorganisms

The efficiency of an oil-oxidizing microbial community in the bioremediation of oil-polluted soil was studied under laboratory conditions. A specific feature of the community was its ability to oxidize oil hydrocarbons under both aerobic and anoxic conditions. The degree of oil-hydrocarbon degradation in various bioremediation modes increased as follows: self-remediation (40%) < nitrate application (42%) < introduction of the denitrifying oil-oxidizing community (50%) < introduction of the denitrifying oil-oxidizing community plus nitrate application (60%). The intensification of bioremediation is related to the increase in the population of the hydrocarbon-oxidizing microorganisms, first of all, denitrifying ones, resulting from the introduction of the community.     

Purification of Soil from Oil Pollutants with the Use of Denitrifying Hydrocarbon-Oxidizing Microorganisms

The efficiency of an oil-oxidizing microbial community in the bioremediation of oil-polluted soil was studied under laboratory conditions. A specific feature of the community was its ability to oxidize oil hydrocarbons under both aerobic and anoxic conditions. The degree of oil-hydrocarbon degradation in various bioremediation modes increased as follows: self-remediation (40%) < nitrate application (42%) < introduction of the denitrifying oil-oxidizing community (50%) < introduction of the denitrifying oil-oxidizing community plus nitrate application (60%). The intensification of bioremediation is related to the increase in the population of the hydrocarbon-oxidizing microorganisms, first of all, denitrifying ones, resulting from the introduction of the community.     

Taguchi DoE methodology for modeling of synthetic dye biosorption from aqueous effluents: parametric and phenomenological studies

Abstract

Biosorption technology has been acknowledged as one of the most successful treatment approaches for colored industrial effluents. The problems such as its high manufacturing cost and poor regeneration capability in the use of activated carbon as a biosorbent have prompted the environmental scientists to develop alternative biosorbent materials. In this context, as a sustainable green generation alternative biosorbent source, the discarded seed biomass from pepper (Capsicum annuum L.) processing industry was explored for the biotreatment of colored aqueous effluents in this study. To test the wastewater cleaning ability of biosorbent, Basic red 46 was selected as a typical model synthetic dye. Taguchi DoE methodology was employed to study the effect of important operational parameters, contact time, pH and synthetic dye concentration, on the biosorption process and to develop a mathematical model for the estimation of biosorption potential of biosorbent. The percentage contribution of each of these process variables on the dye biosorption was found to be 19.31%, 41.39%, and 38.74%, respectively. The biosorption capacity under the optimum environmental conditions, contact time of 360?min, pH of 8 and dye concentration of 30?mg L^?1, was estimated to be 92.878?mg g^?1 (R²: 99.45). This value was very close to the experimentally obtained dye removal performance value (92.095?mg g^?1). These findings indicated the high ability of Taguchi DoE technique in the optimization and simulation of dye biosorption system. The kinetic and equilibrium modeling studies showed that the pseudo-second-order and Langmuir models were the best models for the elucidation of dye removal behavior of biosorbent. The thermodynamic studies displayed that the dye biosorption was a feasible, spontaneous and exothermic process. This parametric and phenomenological survey revealed that the discarded pepper seed biomass can be introduced as a potential and efficient biosorbent for the bioremediation of colored industrial effluents.     

Application of a novel phyco-composite biosorbent for the biotreatment of aqueous medium polluted with manganese ions

A composite phyco-biomass including four different marine macroalgae species (Chaetomorpha sp., Polysiphonia sp., Ulva sp., and Cystoseira sp.) was evaluated as a novel biosorbent for the biosorption of manganese ions from aqueous solution. The experimental studies were performed to optimize the operational factors including solution pH, biosorbent amount, initial manganese concentration, and reaction time in a batch-mode biosorption system. The removal yield of the biosorbent for manganese ions increased with increasing pH, manganese ion concentration, and reaction time, while it decreased as the biosorbent dose increased. The obtained kinetic data indicated that the removal of manganese ions by the biosorbent was best described by the pseudo-second-order model and the pore diffusion also contributed to the biosorption process. The results of isotherm and thermodynamic studies showed that the Freundlich model represented the biosorption equilibrium data well and this biotreatment system was feasible, spontaneous, and physical. The maximum manganese uptake capacity of used biosorbent was found to be 55.874 mg g^?1. Finally, a single-stage batch manganese biosorption system was designed and its kinetic performance was evaluated. All these findings revealed that the prepared composite macroalgae biosorbent has a fairly good potential for the removal of manganese ions from the aqueous medium.     

Biosorption of silver ions by processed Aspergillus niger biomass

Summary An alkali treated A. niger biomass was found to efficiently sequester silver ions from dilute as well as concentrated solutions (2.5–1000 ppm Ag⁺), with an ability to bind it to a level of upto 10% of dry weight. Biosorption of silver ions was not influenced by pH between 5–7. The bound Ag⁺ could be fully desorbed by dilute HNO₃ and the biosorbent regenerated by washing with Ca²⁺/Mg²⁺ solution. This biosorbent is unique in that the mechanism of metal ion sorption has been found to be exclusively by stoichiometric exchange with Ca²⁺ and Mg²⁺ of the biosorbent.     

Bioremediation potential of a widespread industrial biowaste as renewable and sustainable biosorbent for synthetic dye pollution

In this study, a model synthetic azo dye (Basic red 46) bioremoval by Carpinus betulus sawdust as inexpensive, eco-friendly, and sustainable biosorbent from aqueous solution was examined in a batch biosorption system. The effective environmental parameters on the biosorption process, such as the value of pH, amount of biosorbent, initial dye concentration and contact time were optimized using classical test design. The possible dye-biosorbent interaction was determined by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The equilibrium, thermodynamic, and kinetic studies for the biosorption of Basic red 46 onto the sawdust biomass were performed. In addition, a single-stage batch dye biosorption system was also designed. The dye biosorption yield of biosorbent was significantly influenced by the change of operating variables. The experimental data were best described by the Freundlich isotherm model and both the pseudo-first-order kinetic and the pseudo-second-order kinetic models. Thermodynamic research indicated that the biosorption of dye was feasible and spontaneous. Based on the Langmuir isotherm model, the biosorbent was found to have a maximum biosorption potential higher than many other biosorbents in the literature (264.915?mg g^?1). Thus, this investigation presents a novel green option for the assessment of waste sawdust biomass as a cheap and effective biosorbent material.     

Modeling of Pb(II) adsorption by a fixed-bed column

Removal of Pb(II) from an aqueous environment using biosorbents is a cost-effective and environmentally benign method. The biosorption process, however, is little understood for biosorbents prepared from plant materials. In this study, the biosorption process was investigated by evaluating four adsorption models. A fixed-bed column was prepared using a biosorbent prepared from the aquatic plant Hydrilla verticillata. The effect of bed height and flow rate on the biosorption process was investigated. The objective of the study was to determine the ability of H. verticillata to biosorb Pb(II) from an aqueous environment and to understand the process, through modeling, to provide a basis to develop a practical biosorbent column. Experimental breakthrough curves for biosorption of 50 mg L^?1 aqueous Pb(II) using a fixed-bed column with 1.00 cm inner diameter were fitted to the Thomas, Adams-Bohart, Belter, and bed depth service time (BDST) models to investigate the behavior of each model according to the adsorption system and thus understand the adsorption mechanism. Model parameters were evaluated using linear and nonlinear regression methods. The biosorbent removed 65% (82.39 mg g^?1 of biosorbent) of Pb(II) from an aqueous solution of Pb(NO₃)₂ at a flow rate of 5.0 ml min^?1 in a 10 cm column. Na₂CO₃ was used to recover the adsorbed Pb(II) ions as PbCO₃ from the biosorbent. The Pb(II) was completely desorbed at a bed height of 10.0 cm and a flow rate of 5.0 ml min^?1. Fourier transform infrared (FT-IR) analysis of the native biosorbent and Pb(II)-loaded biosorbent indicated that the hydroxyl groups and carboxylic acid groups were involved in the metal bonding process. The FT-IR spectrum of Pb(II)-desorbed biosorbent showed an intermediate peak shift, indicating that Pb(II) ions were replaced by Na⁺ ions through an ion-exchange process. Of the four models tested, the Thomas and BDST models showed good agreement with experimental data. The calculated bed sorption capacity N₀ and rate constant k_a were 31.7 g L^?1 and 13.6 × 10^?4 L mg^?1 min^?1 for the C_t/C₀ value of 0.02. The BDST model can be used to estimate the column parameters to design a large-scale column.     

Senna auriculata L. flower petal biomass: An alternative green biosorbent for the removal of fluoride from aqueous solutions

Fluoride contamination in groundwater is a major concern in many parts of India and all over the world. Researches paying attention for the removal of fluoride through the application of biosorbents prepared from different parts of plants are finding greater scope and importance. The present research work focuses on Senna auriculata L., flower petal biomass as biosorbent, and evaluated its feasibility for fluoride ion elimination from aqueous solutions. Batch experiments were conducted to remove fluoride under different experimental conditions have been optimized for the maximum removal of fluoride; 80% removal was observed at pH: 6, sorbent dosage: 0.25 g/100 mL, time of agitation: 90 min, and initial concentration of the fluoride ions: 5 mg/L. Characterization studies of the biosorbent revealed its favorability towards the sorption of fluoride. In the isothermal modeling studies, Langmuir isotherm model was obeyed by the biosorption process with R² value of 0.98 and from a kinetic perspective, the biosorption of fluoride onto the biosorbent observed the pseudo-second-order reaction with R² value of 0.98. The developed biosorbent has been applied to real field fluoride-contaminated water samples and found to be successful.     

A Novel High Biosorbent of Pb-resistant Bacterium Isolate for the Removal of Hazardous Lead from Alkaline Soil and Water: Biosorption Isotherms In Vivo and Bioremediation Strategy

A novel Pb-resistant bacterium was isolated from aged lead-contaminated alkaline soils, and was identified as Bacillus megaterium via the MIDI protocol. The biosorption isotherms and kinetics of Pb(II) associated with B. megaterium in vivo in the alkaline environment were investigated at the first time. All the batch experiments of biosorption demonstrate that the B. megaterium uptake of lead is pH-dependent, exothermic (ΔH° = ?5224.86 KJ mol^?1), spontaneous, and fits well with the Langmuir isotherm, resulting in different kinetics under different examination temperatures. The maximum biosorption capacity is 503.86 mg g^?1 at optimum conditions, which is much better in comparison to the biosorbent reported at the acidic condition in the literature. The Fourier-transform Infrared spectroscopic analysis of lead-loaded biomass confirms that the biosorption between B. megaterium and lead is the chemical adsorption in vivo. A site test indicates that B. megaterium really increases mobility and bioavailability of lead in Pb-contaminated alkaline soil in terms of chemical fractionation in vivo, which will potentially increase its uptake by hyperaccumulated plants in alkaline soils in arid or semi-arid areas of NW, China. Therefore, the novel isolate of B. megaterium with the highest adsorption capacity is a new promising biosorbent for the lead removal in alkaline water and soil.     

Biosorption of inorganic and methyl mercury by a biosorbent from Aspergillus niger

A biosorbent prepared by alkaline extraction of Aspergillus niger biomass was evaluated for its potential to remove mercury species – inorganic (Hg²⁺) and methyl mercury (CH₃Hg⁺) – from aqueous solutions. Batch experiments were carried out to determine the pH and time profile of sorption for both species in the pH range 2–7. The Hg²⁺ exhibited more rapid sorption and higher capacity than the CH₃Hg⁺. Further, removal of both mercury species from spiked ground water samples was efficient and not influenced by other ions. Sorption studies with esterified biosorbent indicated loss of binding of both mercury species (>80%), which was regained when the ester groups were removed by alkaline hydrolysis, suggesting the involvement of carboxyl groups in binding. Further, no interconversion of sorbed species occurred on the biomass. The biosorbent was reusable up to six cycles without serious loss of binding capacity. Our results suggest that the biosorbent from Aspergillus niger can be used for removal of mercury and methyl mercury ions from polluted aqueous effluents.     

Preconcentration with Bacillus subtilis–Immobilized Amberlite XAD-16: Determination of Cu2+ and Ni2+ in River,Soil, and Vegetable Samples

Solid-phase extraction (SPE) method was developed for the preconcentration of Cu²⁺ and Ni²⁺ before their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Bacillus subtilis–immobilized Amberlite XAD-16 was used as biosorbent. Effects of critical parameters such as pH, flow rate of samples, amount of Amberlite XAD-16 and biosorbent, sample volume, eluent type, and volume and concentration of eluent on column preconcentration of Cu²⁺ and Ni²⁺ were optimized. Applicability of the method was validated through the analysis of the certified reference tea sample (NCS ZC73014). Sensitivity of ICP-OES was improved by 36.4-fold for Cu²⁺ and 38.0-fold for Ni²⁺ by SPE-ICP-OES method. Limit of quantitation (LOQ) was found to be 0.7 and 1.1 ng/ml for Cu²⁺ and Ni²⁺, respectively. Concentrations of Cu²⁺ and Ni²⁺ were determined by ICP-OES after application of developed method. Relative standard deviations (RSDs) were lower than 4.9% for Cu²⁺ and 7.9% for Ni²⁺. The Tigris River that irrigates a large agricultural part of Southeast Turkey is polluted by domestic and industrial wastes. Concentrations of Cu²⁺ and Ni²⁺ were determined in water, soil, and some edible vegetables as a biomonitor for heavy metal pollution.     

Biosorption and Desorption of Lead(II) by Hydrilla verticillata

The potential of nonliving biomass of Hydrilla verticillata to adsorb Pb(II) from an aqueous solution containing very low concentrations of Pb(II) was determined in this study. Effects of shaking time, contact time, biosorbent dosage, pH of the medium, and initial Pb(II) concentration on metal-biosorbent interactions were studied through batch adsorption experiments. Maximum Pb(II) removal was obtained after 2 h of shaking. Adsorption capacity at the equilibrium increased with increasing initial Pb(II) concentration, whereas it decreased with increasing biosorbent dosage. The optimum pH of the biosorption was 4.0. Surface titrations showed that the surface of the biosorbent was positively charged at low pH and negatively charged at pH higher than 3.6. Fourier transform infrared (FT-IR) spectra of the biosorbent confirmed the involvement of hydroxyl and C?O of acylamide functional groups on the biosorbent surface in the Pb(II) binding process. Kinetic and equilibrium data showed that the adsorption process followed the pseudo-second-order kinetic model and both Langmuir and Freundlich isothermal models. The mean adsorption energy showed that the adsorption of Pb(II) was physical in nature. The monolayer adsorption capacity of Pb(II) was 125 mg g^?1. The desorption of Pb(II) from the biosorbent by selected desorbing solutions were HNO₃ > Na₂CO₃ > NaOH > NaNO₃.     

Biosorption of iron(III)–cyanide complex anions to Rhizopus arrhizus: application of adsorption isotherms

The biosorption of iron(III)–cyanide complex anions to Rhizopus arrhizus was investigated. The iron(III)–cyanide complex ion binding capacity of the biosorbent was a function of initial pH, initial iron(III)–cyanide complex ion and biosorbent concentration. These results indicated that a significant reduction of iron(III)–cyanide complex ions was achieved at pH 13, a highly alkaline condition. The maximum loading capacity of biosorbent was 612·2 mg g⁻¹ at 1996·2 mg litre⁻¹ initial iron(III)–cyanide complex ion concentration at this pH. The Freundlich, Langmuir and Redlich–Peterson adsorption models were fitted to the equilibrium data at pH 3·0, 7·0 and 13·0. The equilibrium data could be best fitted to by all the adsorption models over the entire concentration range (50–2000 mg litre⁻¹) at pH 13.     

Biosorption characteristics of Aspergillus fumigatus for the decolorization of triphenylmethane dye acid violet 49

This study focuses on the possible use of Aspergillus fumigatus to remove acid violet 49 dye (AV49) from aqueous solution. In batch biosorption experiments, the highest biosorption efficiency was achieved at pH 3.0, with biosorbent dosage of 3.0 gL^?1 within about 30 min at 40 °C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of AV49 onto fungal biomass with maximum dye uptake capacity 136.98 mg g^?1. Biosorption followed a pseudo-second-order kinetic model with high correlation coefficients (R ²?>?0.99), and the biosorption rate constants increased with increasing temperature. Thermodynamic parameters indicated that the biosorption process was favorable, spontaneous, and endothermic in nature, with insignificant entropy changes. Fourier transform infrared spectroscopy strongly supported the presence of several functional groups responsible for dye–biosorbent interaction. Fungal biomass was regenerated with 0.1 M sodium hydroxide and could be reused a number of times without significant loss of biosorption activity. The effective decolorization of AV49 in simulated conditions indicated the potential use of biomass for the removal of color contaminants from wastewater.     

POTENTIAL USE OF LEAF BIOMASS,ARAUCARIA HETEROPHYLLA FOR REMOVAL OF Pb+2

The present investigation attempt to analyze the biosorption behavior of novel biosorbent, Araucaria heterophylla (green plant) biomass, for removal of Pb⁺² from solution as the function of initial metal ion concentration, pH, temperature, sorbent dosage and biomass particle size. The maximum biosorption was found to be 95.12% at pH 5 and biosorption capacity (q_e) of Cd⁺² is 9.643 mg/g. The Langmuir and Freundlich equilibrium adsorption isotherms were studied and observed that Freundlich model is best fit than the Langmuir model with correlation coefficient of 0.9927. Kinetic studies indicated that the biosorption process of Cd⁺² followed well pseudo second order model with R² 0.999. The process is exothermic and, spontaneous. The chemical functional groups –OH, CH₂ stretching vibrations, C?O of alcohol, C?O of amide, P?O stretching vibrations, –CH, were involved in the process. The XRD pattern of the A. heterophylla was found to be mostly amorphous in nature. The SEM studies showed Pb⁺² biosorption on selective grains of the biosorbent. It was concluded that A. heterophylla leaf powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Pb⁺² from aqueous solution.     

Copper biosorption on Lyngbya putealis: Application of response surface methodology (RSM)

The potential use of biosorbent prepared from an indigenously isolated cyanobacterium, Lyngbya putealis, for the removal of copper from aqueous solution has been investigated under optimized conditions in this study. Batch mode experiments were performed to determine the adsorption equilibrium and kinetic behavior of copper in aqueous solution allowing the computation of kinetic parameters and maximum metal adsorption capacity. Influences of other parameters like initial metal ion concentration (10-100 mg l⁻¹), pH (2-8) and biosorbent dose (0.1-1.0 g/100 ml) on copper adsorption were also examined, using Box-Behnken design matrix. Very high regression coefficient between the variables and the response (R² = 0.9533) indicates excellent evaluation of experimental data by second order polynomial regression model. The response surface method indicated that 40-50 mg l⁻¹ initial copper concentration, 6.0-6.5 pH and biosorbent dose of 0.6-0.8 g/100 ml were optimal for biosorption of copper by biosorbent prepared from L. putealis. On the basis of experimental results and model parameters, it can be inferred that the biosorbent which has quite high biosorption capacity can be utilized for the removal of copper from aqueous solution.     

Optimization of the purification of soil and water objects from oil using biosorbents

Oil biosorbents (patents 2299181, 2318736) were obtained using immobilization of oil-oxidizing microorganisms into the hydrophobic sorbent Sorbonaft, which is manufactured using special technology at the Press-Torf Company. Two associations of aboriginal hydrocarbon-oxidizing microorganisms were used for this purpose: a fungal association and a bacterial and yeast association. The application of biosorbents resulted in a substantial acceleration of the process of purification from oil. The decrease in the amount of oil in the water and soil during 1 month was 30–44% in the variants with the products, against 5% in the control.