Biosorption of heavy metals Research Papers (original) (raw)

In this study, a renewable biosorbent material was prepared from biological waste of widespread coastal plant, Zostera marina and employed for the biosorption of heavy metal pollution from water environment in green way. Manganese was selected as a model heavy metal to evaluate the treatment efficiency of prepared biosorbent. The batch biosorption behavior of biosorbent was investigated by the characterization, parameters evaluation, kinetic and equilibrium studies. The characterization study showed that the biosorbent has a rough surface and various binding groups for the heavy metal ions. The heavy metal concentration of 30 mg L⁻¹, time of 60 min, pH of 6 and biosorbent amount of 10 mg were determined as the optimum biosorption conditions. The pseudo-second-order equation was found to be the best among kinetic models applied. The equilibrium data were best explained by Freundlich isotherm. The maximum biosorption efficiency based on Langmuir model was predicted as 58.426 mg g⁻¹. Hence, the current work presents a renewable alternative biosorbent substance for the green treatment of heavy metal pollution from water medium.

The equilibrium and thermodynamics of the biosorption of Pb(II), Zn(II), Cu(II), and Cd(II) onto activated carbon prepared from olive branches were studied under different parameters of pH, initial concentration, and temperature. The batch biosorption procedure was used to find the optimum conditions. The biosorption of each metal ion was found to be pH-dependent. The maximum metal ion biosorption was achieved at pH value 5 for Pb, Cu, and Cd ions and at pH 3 for Zn ions. The extent of the metal ion biosorption increased with temperature (indicating the endothermic character) and initial metal ion concentration. The experimental data of metal ion biosorption were analyzed by Freundlich and Langmuir isotherm models. For all metal ions, the Freundlich isotherm model gave a better fit with higher correlation (R 2) to equilibrium data than Langmuir model. The adsorption capacity values were 41.32, 34.97, 43.10, and 38.17 (mg/g) for Pb(II), Zn(II), Cu(II) and Cd(II), respectively. Thermodynamically parameters, like Gibbs free energy (ΔG˚), enthalpy (ΔH˚), and entropy (ΔS˚) were calculated. The biosorption of each metal ion was non-spontaneous and the order of non-spontaneity of the biosorption process being Zn(II) > Cu(II) > Cd(II) > Pb(II). Likewise, change in entropy was noticed for each metal ion and the order of disorder was Pb(II) > Cd(II) > Cu(II) > Zn(II).

The equilibrium and thermodynamics of the biosorption of Pb(II), Zn(II), Cu(II), and Cd(II) onto activated carbon prepared from olive branches were studied under different parameters of pH, initial concentration, and temperature. The batch biosorption procedure was used to find the optimum conditions. The biosorption of each metal ion was found to be pH-dependent. The maximum metal ion biosorption was achieved at pH value 5 for Pb, Cu, and Cd ions and at pH 3 for Zn ions. The extent of the metal ion biosorption increased with temperature (indicating the endothermic character) and initial metal ion concentration. The experimental data of metal ion biosorption were analyzed by Freundlich and Langmuir isotherm models. For all metal ions, the Freundlich isotherm model gave a better fit with higher correlation (R2) to equilibrium data than Langmuir model. The adsorption capacity values were 41.32, 34.97, 43.10, and 38.17 (mg/g) for Pb(II), Zn(II), Cu(II) and Cd(II), respectively. Thermodynamically parameters, like Gibbs free energy (ΔG˚), enthalpy (ΔH˚), and entropy (ΔS˚) were calculated. The biosorption of each metal ion was nonspontaneous and the order of non-spontaneity of the biosorption process being Zn(II) > Cu(II) > Cd(II) > Pb(II). Likewise, change in entropy was noticed for each metal ion and the order of disorder was Pb(II) > Cd(II) > Cu(II) > Zn(II)

في هذا البحث أستخدم مسحوقي القهوة والشاي كمادة مازة طبيعية لأيونات الحديد، النحاس، والكوبلت. وجد أن عملية الامتزاز تعتمد بشكل كبير على مجموعة من المتغيرات وهي الرقم الهيدروجيني، كمية المادة المازة، والتركيز الأولي لأيون المعدن. أستخدم نموذجي لانجماير وفرويندليش من أجل دراسة عملية الاتزان لهذه الأنظمة، حيث وجد أن نموذج لانجماير أكثر ملائمة لتفسير هذه الأنظمة وذلك من خلال قيمة معاملات الارتباط R ( 2 ( والتي كانت أكبر من 1.77 . قيم سعة الامتزاز المحسوبة من خلال نموذج لانجماير كانت لمسحوق القهوة 344،36،32.2 ملجم/جم، وبالنسبة لمسحوق الشاي 344،409،326 ملجم/جم، وذلك لأيونات الحديد، النحاس، والكوبلت، على التوالي. وفقا للنتائج المتحصل عليها فإن مسحوقي القهوة والشاي يعتبر من المواد المازة الفعالة، غير المكلفة، والصديقة للبيئة في ازالة العناصر الثقيلة من المحاليل المائية

- by Chemistry International and +2
- •
- Thermodynamics, Kinetics, Biosorption, Adsorption

This study presents the isolation and screening of manganese (II) oxidizing bacteria from
wastewater samples of electroplating industrial effluent and its application as a potential biosorbent to
remove Mn(II) ions from aqueous solution in a batch system. A statistical approach, the response surface
methodology is used to determine the optimum conditions for the generation of biogenic manganese oxides
and manganese removal using manganese oxidizing bacterial strain Mn 21. Based on the statistical analysis;
the maximum biogenic manganese oxide formation and manganese removal was obtained 64.90% and
96.90% at pH 8, temperature 300C and 10 days incubation time. We can achieve a maximum removal and
Mn oxide formation upto 108.9% and 71.1% respectively at optimal conditions of pH 8.0, temperature
31.70C and incubation time of 9.7 days having maximum desirability. The analysis of variance (ANOVA)
of Box–Behnken design showed that the proposed quadratic model fitted experimental data very well with
coefficient of correlation r2 to be 0.9821, 0.9744 for manganese removal and manganese oxide formation
respectively.

- by Shaalu Duddi
- •
- Biosorption of heavy metals, Biogenic Manganese Oxides

In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concentration, temperature and agitation speed was studied. Thermodynamic parameters, equilibrium isotherms and kinetic data have been evaluated. The functional groups and surface morphology of SH adsorbent were characterized by FTIR and SEM. Adsorption equilibrium isotherms were expressed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models and it was found that Langmuir adsorption model fits the experimental data better than Freundlich and D-R models. The adsorption can be best described by the pseudo second-order kinetic model. The maximum adsorption capacity of SH was compared to that of other reported adsorbents.

- by Haitham Ahmed El-Araby Mohammed and +1
- •
- Thermodynamics, Kinetics, Water and wastewater treatment, Biosorption

The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility.► A number of groundwater treatment technologies for heavy metal remediation have been reviewed. ► Iron based techniques, Biological Sulphate Reduction and Permeable Reactive Barriers were most successful in the past decade. ► Biosorption is the emerging field mostly experimented in laboratories. ► More than one techniques can be coupled for site specific problems for better performance.

Bioflocculant Biopolymer Exopolysaccharide FTIR and NMR LC–MS and SEM Flocculation Heavy metals a b s t r a c t Optimization of process parameters enhanced bioflocculating activity of 'Achromobacter xylosoxidans strain TERI L1' from 75% to 83.3% in absence of heavy metals, which decreased to 73% in presence of multi-metals. 'TERI L1' could adsorb 90% of multi-metals when grown in presence of 1250 mg L −1 Zn, 2 mg L −1 Cd, 30 mg L −1 Pb, 200 mg L −1 Ni and 90 mg L −1 Cu and could adsorb 1100 mg L −1 of Pb when grown in presence of 1500 ppm lead nitrate. The bioflocculant was purified and characterized. Bioflocculant yield was 5 g L −1. Fourier transform infrared spectrum indicated presence of carboxyl, hydroxyl, amino groups, typical of glycoprotein. Spectroscopic analysis of bioflocculant by nuclear magnetic resonance revealed that it is a glycoprotein. LC–MS analysis confirmed the bioflocculant as a carbohydrate hetero polymer. Biofloc-culant was composed of 75% total sugar with 72.9% neutral sugar and 11.5% protein. Scanning Electron Micrography revealed effective flocculation of kaolin clay by purified exopolysaccharide bioflocculant.

- by Neha Batta
- •
- Biosorption of heavy metals, Biofloculant

The utilization of microorganisms as biosorbents for the removal and recovery of heavy metals from industrial wastewaters has become a major alternative to conventional methods. Biosorption is one of those methods which implement microorganisms for that purpose. Microorganisms, active or inactive, can adsorb dissolved metals by courtesy of their special membrane characteristics. The design of the appropriate equipment and the estimation of optimum process input values have a great importance concerning the analysis and synthesis of the process under investigation. In order to obtain a dependable optimization scheme, the evaluation of a wide collection of biosorption data is required. Instead of using a time consuming and expensive database matrix, the development of a suitable mathematical model depending on process principles and a truncated experimental data may be more efficient approach to establish an optimization result.A satisfactorily accurate model of a system can be used to predict outcomes under varying conditions without the need for actual experimentation and observation. In this study, the inactiveand dried biomass of Schizosaccharomycespombe, a species of unicellular yeasts, was used as biomass for the bioremoval of Ni2+.S.pombe (972) was grown at its optimum media.Biosorption experiments were done at varying experimental conditions such as pH, temperature, metal concentration. The biomass was added to a 100 mL Ni (II) solution at predetermined initial metal (1, 2, 5, 10, 50 mg g-1), temperature(25, 30, 35, 50 C°)and pH (4.0, 5.0, 6.0) values to get a mixture of 1 g L-1sorbent content. Biosorption operations were performed in 250 mL Erlenmeyer flasks which were agitated in an incubator shaker at 150 rpm for a total period of 2 h. As a result, effects of temperature, starting metal concentration and pH were investigated during the experiments. Autofit 3.0 program was used for the equilibrium studies by trying different isotherms running with different algorithms such as Levenberg-Marquardtand Maximum Inherit Optimization.A mathematical model was developed to evaluate the relevant data. Reliability and accuracy of the model were tested using chi-square statistical method. This approach is a significant simulated description of examined process.

- by Rumeysa Ozen
- •
- Mathematical Modelling, Biosorption of heavy metals

Heavy metal removal from water is an important issue of environmental concern. This study demonstrates the application of endophytic bacterium Kocuria rhizophila (gene bank No: KF875448) isolated from hyperaccumulator Oxalis corniculata for the adsorption of Cd(II) and Cr(III) from aqueous solution. Minimum inhibitory concentration of Cd and Cr for the selected strain was found to be 6 and 8 mM, respectively. The effects of certain parameters like pH, contact time, and initial metal concentration on biosorption were assessed at a temperature of 35 ± 2˚C. The optimum pH values for Cd and Cr biosorption were found to be 8 and 4, respectively. Maximum biosorption for both the metals was obtained after 60 min. Biosorption equilibrium was described by Langmuir and Freundlich isotherms. The Langmuir model showed maximum adsorption capacity (Qmax) for Cd and Cr as 9.07 and 14.4 mg g−1, respectively. Kinetic data indicated that biosorption of the selected heavy metals on K. rhizophila follows pseudo-second-order rate equation. FTIR analysis showed that functional groups like OH, C=O, C=N, N–H, CH2, PO2, C–O, C–O–C and C–H on K. rhizophila surface might be responsible for heavy metals biosorption. Results suggested that K. rhizophila has potential for the removal of metal ions from aqueous solution. Therefore, current research presents novelty in terms of evaluating endophytic K. rhizophila as a biosorbent for Cd and Cr.

- by Fazal Haq and +1
- •
- Endophytes, Biosorption of heavy metals, Plant-Microbe Interactions, Microbial Cleaning of Water

In general, the biosorption of heavy metals by various types of non-living organisms appears to be a very effective, low-cost and innovative method for their removal from aquatic environments. The aim of this study was to determine the applicability of adsorption isotherms and kinetic models during the biosorbent activity of non-living Chlorella to the removal of Cd, Cu and Pb. Dead cells of Chlorella vulgaris were used to remove these heavy metals from aqueous solution in experimental conditions, i.e. under various condition of pH, biosorbent dosage and contact time. Afterwards, the Langmuir and Freundlich adsorption isotherm models and the sorption kinetics (pseudo-first and pseudo-second order models, and intraparticle diffusion) were applied to the experimental data to check the effectiveness of the removal process. The removal of heavy metals on C. vulgaris following the order of Pb +2 > Cu +2 > Cd +2 was confirmed by the maximum biosorption capacities (q max), the Langmuir constant (b), separation factor (R L) and Freundlich intensity parameter (1/n) values. The equilibrium data were well fitted with the Langmuir and Freundlich isotherm models. The adsorption process followed the pseudo-second-order model and it suggested that such kinetics is the most effective. The present results confirmed highly efficient biosorbent activity of C. vulgaris in the removal of heavy metals, especially Cd, Cu and Pb, from aqueous solution. The environmentally friendly origin indicates that non-living cells of C. vulgaris could find many broad-scale, cost-effective and alternative applications.

Three sets of experiments (Laboratory, diallel and stability)
were conducted at the Faculty of Agriculture, Zagazig
University, during the winter successive growing seasons
2012/2013 and 2013/2014 to generate informations about the
impact of heavy metals (Zn, Pb and Cd) on seed germination,
seedling growth, performance, heterosis, combining ability,
genetic behavior and stability of some bread wheat genotypes.

Heavy metal pollution is a major environmental problem, especially around highways with high traffic density.
This study investigates the levels of Pb, Cd, Zn and Cu in roadside soils of Wukari section of the Wukari-Jalingo
highway, Taraba state, Nigeria. Samples were randomly collected and analyzed using standard methods. The
mean concentrations (μg/g) of Pb, Cd, Zn and Cu from all sample sites ranged: 89.6-247.0, 0.15-5.3, 26.8-163.0
and 7.1-61.2 respectively. The extent of the heavy metals contamination was assessed, as analytical data were
subjected to pollution calculation methods. The contamination factors (CF) reveal extreme contamination of the
sites and an increasing trend in the heavy metals concentrations was observed in sites with more human
activities. The pollution load index (PLI) showed that the sites are severely polluted as the PLI of the metals from
each sample site exceeded the PLI of the background (control) sample (0.7). Spearman’s rank correlation
analysis showed clear correlations (p<0.001) amongst the metals suggesting a common source. It can be
concluded that the study sites pollution is mostly due to automobile emissions. This study provides awareness
for residents to avoid activities such as farming, trading etc very close to the highway due to exposures to these
toxic metals.

- by Lamiaa Mohamedein
- •
- Algae, Biosorption of heavy metals
- by Suresh Mahiya
- •
- Heavy Metal Pollution, Biosorption of heavy metals

Seven species of brown, green, and red seaweeds were examined for their abilities to sequester cadmium ions from aqueous solution. Although all the seaweed types investigated were capable of binding appreciable amounts of cadmium, considerable variability in their biosorption performance was observed. Maximum cadmium uptake capacities at pH 5 ranged from the highest value of 0.74 mmol/g for the brown seaweed Sargassum baccularia to the lowest value of 0.16 mmol/g for the red seaweed Gracilaria salicornia, representing a 363% difference. In general, brown seaweeds were found to exhibit the best overall cadmium ion removal. Additional experiments were conducted to evaluate the biosorption characteristics of the brown seaweed S. baccularia. The equilibrium uptakes of cadmium were similar within the pH 3–5 range but decreased significantly when the solution pH was reduced to pH 2. The presence of background cations such as sodium, potassium, and magnesium and anions such as chloride, nitrate, sulphate, and acetate up to a concentration of 3.24 mmol/l was found to have no significant effect on the equilibrium uptake of cadmium. However, the biosorbent uptake of cadmium was markedly inhibited in the presence of calcium ions at 3.24 mmol/l. Kinetic studies revealed that cadmium uptake was fast with 90% or more of the uptake occurring within 30–40 min of contact time.

- by Mohd Ali
- •
- Chemical Engineering, Kinetics, Calcium, Algae

Bioremediation of heavy metal pollution remains a major challenge in environmental Biotechnology. Some industrial processes results in the release of heavy metals into aquatic systems. This has led to increasing concern about the effect of toxic heavy metals as environmental pollutants. One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers, as a more economical, effective and safe alternative to processes such as precipitation, coagulation, ion exchange, electrochemical and membrane processes. Many bacterial polysaccharides have been revealed to join heavy metals with changeable degrees of specificity and resemblance The adsorption of heavy metals by extracellular polymeric substances (EPS) is energy independent, non-metabolism, and can be caused by contact between negative charge and metal cations of acidic functional groups of EPS. Isolated biopolymers have not been practical on a huge range for heavy metal remediation

- by Tamer Alslaibi
- •
- Environmental Engineering, Chemical Engineering, Water quality, Water resources

A new procedure for the determination of chromium species in polluted environmental samples by flame atomic absorption spectrometry was developed in this work. A new material containing 1,5-diphenylcarbazone included in a polymeric matrix was prepared and employed as a solid-phase extraction material for selective separation of Cr(III) ions under dynamic conditions. Chromium(III) ions were retained on this sorbent with high efficiency and repeatability (95 %, RSD = 1 %) from solutions with pH 9.0. The quantitative recovery of analyte was obtained with 0.1 mol L −1 EDTA. The concentration of Cr(VI) ions was calculated from the difference between the concentration of total chromium and Cr(III) ions. The prepared sorbent exhibits good chemical and mechanical stability, sorption capacity and selectivity towards Cr(III) ions in the presence of Cu(II), Ni(II), Mn(II) and Ca(II) ions. The accuracy of the separation method was proved by analysis of reference material of wastewater RES 10.2. The developed procedure was applied for chromium speciation analysis in municipal sewage samples.

- by Beata Godlewska-Żyłkiewicz and +1
- •
- Sorbents, Metal speciation, Atomic Absorption Spectrometry, Biosorption of heavy metals

BACKGROUND: Bacterial strains belonging to the genus Bacillus, isolated from Cr- polluted soil (tannery sludge)were employed
as consortium for Cr(III) removal from tannery effluents. Kaolin clay, a natural adsorbent, was used as supporting material for
bacterial biofilm formation. The use of clay-supported bacterial biofilm has not previously been employed for the treatment of
tannery effluents containing Cr(III) salt.
RESULTS: Commercial tannery effluent containing 1000 ppm initial metal ion concentration was treated in stages. The initial
Cr(III) concentration of 1000 ppm was brought down to 2 ppm, a permissible level for discharge, after the fourth stage. The
bacterial isolates were found to be Bacillus subtilis VITSCCr01 and Bacillus cereus VITSCCr02 by 16s rRNA gene sequencing. Batch
assay and confocal laser scanning microscopy results revealed the role of kaolin as a support material in biofilm formation.
Best fit was obtained with the Freundlich adsorption isotherm. Themechanism of sorption was confirmed by Fourier transform
infrared (FT-IR) spectroscopy and scanning electronmicroscopy–energy dispersive X-ray spectroscopy (SEM-EDS).
CONCLUSION: Cr(III) removal from tannery effluent using low cost adsorbents such as kaolin and bacteria proved to be effective
for metal concentrations ≤1000 ppm; this is normally not possible using conventional treatment methods. This work has
demonstrated feasible sorption of Cr(III), especially during post-tanning operations.

- by Aafreen Fathima
- •
- Heavy Metal Pollution, Biosorption of heavy metals
- by Angelyn Sager
- •
- Biosorption, Biosorption of heavy metals

The present work evaluates the performance of the yeast Saccharomyces Cerevisiae to remove heavy metals from aqueous solutions. The effect of pH, temperature, initial concentration, contact time, and biosorbent dosage on biosorption capacity is studied. Experiment results show that metal uptake is a rapid process at pH values (5.0–6.0), and the order of accumulated metal ions is Pb > Zn > Cr > Co > Cd > Cu. The biosorption process obeys Freundlich and the Langmuir adsorption isotherms. The kinetics of metal ions biosorption could be described by Lagergren and Ho models. Nitric acid with low concentration of 0.05 N is effective in desorbing the biosorbed metal ions. Sodium hydroxide solution of 0.2 M is effective in regenerating the yeast; the regenerated yeast could be used for at least six cycles of biosorption, without losing its metal removal capacity. Carboxyl, amine, and phosphate groups present in the yeast were found to be the main biosorption sites for metal ions.

- by Anees Khadom
- •
- Chemical Engineering, Chemistry, Biosorption, Environmental Chemistry

Mosses sampling were collected from 10 sampling sites within Erbil governorate in October 2015 during dry condition, The samples were air dried and crushed to fine particulates using rotary, then after the heavy metals concentration were determined by XRF spectrophotometer (Sky Instrument Genius). Map of selected mosses distribution were made. The results revealed that the mean values of Pb:52.25 mg/kg , Hg:0.01 mg/kg, Mn:162.8 mg/kg, Fe:1.655%, Cu:8.27 mg/kg, Zn:162 mg/kg, Ti:851.1 mg/kg, Co:6.28 mg/kg, Ni:57.57 mg/kg, As:6.84 mg/kg, Se:0.19 mg/kg and Cr:9.73 mg/kg, The data was statistically analyzed. And the results indicated The significant deference (0.05) between sites and mosses species, The data obtained in this study was compared with that of European countries, reveled that The concentration of studied were less than of WHO recommendation.

- by Soran Rawandze
- •
- Air Quality, Bioindicators, Environmental Monitoring, Air pollution
- by Chemistry International and +1
- •
- Biomass, Adsorption, Heavy metals, Biosorption of heavy metals

The coconut fibers produced in large quantities in Brazil, even though very small quantities are being used by some industries, mainly cordage mats and handicrafts. An alternative usage would be the use these fibers in biosorption of heavy metals from aqueous solutions. This present study aimed to evaluate the potentiality of cadmium sorption by coconut fiber. The coconut fibers were used at kinetic analysis, influence of pH and adsorption isotherms were carried out. It can be concluded that there is a greater potential for the use of coconut fiber, and the ideal pH for adsorption was around 5.0. The adsorption kinetics is fast and equilibrium occurs below 120 minutes. The isotherm Langmuir was considered more correlated with the experimental data.

- by Rasiah Ladchumananandasivam
- •
- Biosorption of heavy metals

The biosurfactant production process was optimized using raw orange peel extract (ST reduction = 33.04 dyne cm − 1 ; biosurfactant yield =~3.7 g L − 1) and the extracted metabolite was characterized in terms of its nature, and class/family. To the best of our knowledge, a first report utilizing biowaste as a sole carbon substrate for simultaneous biosurfactant production and Pb 2+ removal under submerged fermentation by Bacillus haynesii strain E1. The results depicted the extracted biosurfactant to be of lipopeptide nature belonging to surfactin family having 50 mg L − 1 of CMC. The crude biosurfactant was found to be tensioactive at temperature 70 • C, 6% salt concentration, and varying pH range. The biosurfactant-producing bacterium effectively remediated Pb 2+ (high MIC = 2200 mg L − 1) with a maximum adsorption capacity of 196.08 mg g − 1. The biosorption mechanism followed Langmuir (R 2 = 0.9724) and Pseudo second-order adsorption kinetics (R 2 = 0.9996; 200 mg L − 1).

The coffee and tea powders were investigated to be as a novel low-cost non-conventional biosorbent for the removal of Fe (III) from aqueous solutions. Biosorption isotherms and kinetics were also assessed. The studied operating parameters were initial Fe (III) concentration, contact time, pH, and biosorbent dose. The adsorption capacity was significantly increased from 9.18 mg/g to 54.14 mg/g when the initial metal ion concentration increased from 20 to 120 ppm. However, the adsorbed amount of Fe was improved from 2.29 to 23.31 mg/g when the biosorbent dose decreased from 1.0 to 0.1 g. Biosorption isothermal data could be well simulated by Langmuir, Freundlich, and then Temkin models denoted by high correlation coefficient values (R2 > 0.95). However, the Dubinin-Radushkevich isotherms model gives the least fit to experimental data. Langmuir adsorption capacities of coffee and tea were 85.5 and 285 mg/g, respectively. The kinetic data fitted very well to the pseudo-second-order kinetic model. As indicated by the biosorption capacity, coffee and tea powder are considered to be an efficient, low cost, and environmentally friendly biosorbent for the removal of Fe (III) ions from aqueous solutions.

This work evaluated the potential of Aspergillus nidulans biomass in cadmium removal process. The biomass obtained by heat inactivation, and treated with formaldehyde was used to remove cadmium in aqueous solutions, at concentrations of 1mM, 2mM and 3mM, and at pH values of 4, 5 and 6. The results indicate that the isolated displays potential for metal removal. The efficiency depended of pH and treatment. The highest removal rates were obtained at pH 6.0 and with biomass submitted to heat inactivation. The results showed the possibility of application of the isolated biomass in cadmium remediation processes even in high concentrations.

- by Layla C Mahnke
- •
- Microbiology, Biotechnology, Biosorption of heavy metals

The objective of this study is to investigate the effects of contact time (0–48 hrs) and initial concentration of metal ions (5 ppm in 50 mL, 150 mL and 250 mL) to the percentage removal and uptake capacity of by Gramineae Saccharum... more

- by Zamri Abdullah
- •
- Heavy Metal Pollution, Biosorption of heavy metals, Sugarcane Bagasse
- by Nagy Boldizsar
- •
- Biosorption of heavy metals
- by Ivan Traykov and +1
- •
- Heavy Metal Pollution, Biosorption of heavy metals

The chromium bioaccumulation potential in Sinapis alba L. was studied in experimental hydroponic conditions. Mustard seedlings were grown in nutrient solution containing 50, 100, 250 and 500 ppm Cr. After 10 days, seedlings were analyzed for shoot length, biomass, leaf pigment (chlorophylls and carotenoids) and tissular Cr concentration. The Biological Accumulation Coefficients (BAC) were also determined. Cr content in S. alba dry mass reached 415-2,064 ppm, depending on ambient Cr concentration. BAC ranged between 8.30 to 4.13, with a peak at 100 ppm and lowest values at higher concentrations. Shoot length, biomass and pigment concentration values showed an average decrease at high Cr concentrations (mostly, at 500 ppm), without a definite statistical significance. Results indicate that S. alba is tolerant to high Cr levels and has hyperaccumulative abilities.

- by Dan Razvan Popoviciu
- •
- Botany, Plant Physiology (Biology), Plant Physiology, Heavy metals

This study focuses on the investigation of the performance of Litchi chinensis sonn peels in a simulated fixed bed column in sequestering Cr(VI) by breakthrough curve analysis using Aspen Adsorption® V8.4. The breakthrough curve analysis was conducted by: 1) varying initial concentration at a constant flow rate and constant bed height, 2) varying flow rate at a constant initial concentration and constant bed height, and 3) varying bed height at constant flow rate and constant initial concentration. The good adsorption capacity was implied by a longer breakthrough time so as to make use of the peels of Litchi chinensis sonn for a longer period of time before there was a need to replace or to regenerate. Increasing the volumetric flow rate at constant initial sorbate concentration and bed height increased the breakthrough time. Increasing the initial sorbate concentration at constant volumetric flow rate and bed height decreased the breakthrough time. Increasing the bed height at a constant volumetric flow rate and initial sorbate concentration increased the breakthrough time. Longer breakthrough time denotes a better adsorption capacity. The longest breakthrough time was 335 s with volumetric flowrate at 1x10-3 L s-1 , initial sorbate concentration at 20 mg L-1 , and a bed height of 0.7 m. The shortest was 6.63 s with a volumetric flow rate at 1x10-2 L s-1 , initial sorbate concentration at 200 mg L-1 , and a bed height of 0.2m.

- by Ronnel Garcia and +1
- •
- Chemical Engineering, Biosorption, Adsorption, Adsorption and wastewater treatment

In this study, cadmium (Cd), nickel (Ni), and lead (Pb) contents were analyzed in sixteen banana composite samples from different commercial establishments from eleven Ecuadorian production provinces using graphite furnace atomic absorption spectrophotometry. The concentrations (fresh weight) in the samples collected (9.3-47.3 µg·kg −1 for Cd, 16.1-105.6 µg·kg −1 for Ni, and 36.9-538.0 µg·kg −1 for Pb) were used to calculate the estimated daily intake (EDI), target hazard quotient (THQ), and target carcinogenic risk (CR) associated with dietary exposure to these potentially toxic metals. Cd and Ni results showed that every sample had EDIs lower than the oral reference dose and THQ values lower than 1, demonstrating that there was no non-carcinogenic risk related to the exposure to Cd and Ni. In the case of Pb, two EDIs results were higher than the reference dose, also their corresponding THQ values were higher than 1. The lead CR in all samples was less than 1 × 10 −4 , the upper limit used for acceptable cancer risk. Thus, there is no significant health risk to the consumer associated with bananas with contamination levels of Cd, Ni, but there is Pb risk for toddlers (12 kg of body weight) intake comparable to the one detected in the present study.

Biphasic apatite-carbon biochar-type materials were prepared from pyrolysed cod fish bones and were assessed for the adsorption of persistent organic pollutants (pharmaceuticals diclofenac and fluoxetine), and heavy metals (Pb(II)). The materials, prepared with a simple pyrolysis process at different temperatures (200–1000 °C), were characterised with XRD, FTIR, Raman and SEM. Results showed that the pyrolysis temperature had a significant effect on the features / composition of the materials: up to 800 °C, carbonate apatite Ca10(PO4)6(CO3) was the main component, while for higher temperatures oxyapatite Ca10(PO4)6O was the dominant phase. Graphitic carbon was also detected. The mixed apatite-carbon products (bone char) exhibited high adsorption efficiency. Graphite carbon was the main adsorber for the pharmaceuticals, the best performing material being that pyrolysed at 1000 °C. X m values of 43.29 and 55.87 mg/g were observed (Langmuir fitting), while K F values of 5.40 and 12.53 (mg/g)(L/mg) n F were obtained with the Freundhlich model (diclofenac and fluoxetine respectively). This is the first time that a biochar-like material has been used for fluoxetine adsorption. For Pb (II), the powder pyrolysed at 600 °C was the most effective, with the apatite playing a key role (X m = 714.24 mg/g). This work shows that a by-product of the fish industry could be converted into efficient materials for environmental remediation; according to the pyrolysis conditions, powders effective in the removal of either organics or heavy metals can be obtained. Moreover, with pyrolysis at intermediate temperatures, materials capable of adsorbing both kinds of pollutants can be produced, even if less efficient.

The ability of non-living biomass of Penicillium citrinum has been explored for removal and recovery of Ni (II) from aqueous solutions. Biosorption potential of immobilized and free biomass of fungus P. citrinum was studied in batch system for metal removal. The influence of different experimental parameters such as pH, contact time, metal ion concentration and biosorbent dose were investigated. P. citrinum exhibited highest Ni (II) sorption i.e. 97.5 % at pH 6.0, contact time of 30 minutes and biosorbent dose of 0.1 g/100 mL using immobilized biomass whereas maximum removal of 90.2 % was observed with free biomass at 6.0, pH, 40 minutes, contact time and 0.2 g/100mL, biosorbent dose. The biosorption potential of immobilized biomass was higher than that of free biomass of P. citrinum. The adsorption process complied with Langmuir and Freundlich isotherms exhibited very high correlation coefficients which confirmed suitability of model and biosorption process.

- by Shaalu Duddi
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- Bioremediation of wastewater, Biosorption of heavy metals
- by Gökben Başaran
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- Thermodynamics, Kinetics, Biosorption, Environmental Management

Level of a selected heavy metal, cadmium (Cd), emitted from the chimneys of brick manufacturing works and its consequences on surrounding soil and wheat plant were studied Two brick kilns located along the ring road in the area of Sufaid Dheri, Peshawar were selected. Samples
of soil and plant were collected from eighteen different sites at 100, 200 and 300 m distances from brick kiln chimney in all four directions to measure cadmium deposition effect of distance and wind direction. In addition 8 dust samples in duplicate were also collected in plastic buckets installed at
3m height and 50 m distance from the chimney to estimate the dust fall rate and extent of Cd load from brickworks. Results showed higher dust fall rate in all four directions ranging from 23.8 to 46.0 g/m 2 month -1 at 50m distance form the chimney. Taking averages across all direction, higher dust from brick works caused addition of Cd with 0.08 mg/kg. Coal analysis showed that burning of coal may add a huge quantity of Cd in short perod. Such substantial amounts of Cd from dust and coal induced accumulation of this heavy metal in soil and plants around the brick kiln. Plants around the kilns also showed higher accumulation of Cd (up to 7.83 mg/kg) with the distance from chimney.
The study was of high importance showing significant addition of heavy metals from brick works emission and indicates its harmful effect on soils, plants, heritage and human beings, residing in the vicinity of the brickworks. To summarize, the data obtained in this study would present a baseline for the planners, health authorities, scientists and consumers to adopt appropriate remedial measure.

- by Muhammad Iqbal Hashmi
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- Environmental Pollution, Heavy metals, Wheat, Biosorption of heavy metals

Low-cost local plants (eucalyptus bark, moringa pods, pine cones) have been successfully used to remove heavy metals from simulated wastewater. Two types of heavy metals were chosen to study the removal capacity, nickel (Ni) and chrome (Cr), with a concentration of 400, 600, 900 ppm. The results show that moringa pods have the best removal capacity for heavy metals with percentages of 90–99% for both metals, Ni and Cr, for the eucalyptus bark the removal capacity percentages reach 50–98%, while for the pine cones revealed a lower removing capacity with percentages of 40–99%, indicating that this is the lowest removal capacity. The data has been best fitted to the Langmuir adsorption model for all plants, while the Freundlich adsorption model could not fit the obtained results at the experimental conditions. The kinetic study has revealed that the first-order kinetic model successfully describes the kinetics of Ni adsorption, while the second-order describes the kinetics of Cr adsorp...

- by Mohammed Matouq
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- Waste water treatment, Biosorption of heavy metals
- by Maria Saleem and +1
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- Kinetics, Energy Consumption, Titanium, Removal Of Heavy Metals In Contaminated Soils

The most tolerant bacterial strain for copper, lead and cadmium was isolated from El-Manzala Lake, Egypt and it was identified using biochemical tests and confirmed by 16S r RNA gene to be Pseudomonas putida. The optimum conditions for biosorption of the tested metals was investigated by using the bacterial strain. The equilibrium time for copper, lead and cadmium was 25, 30 and 40 minutes, respectively. However, the optimum pH for copper and cadmium biosorption by Pseudomonas putida was 6 , while it was 5 for lead. The experimental biosorption data was fitted towards the models postulated by Langmuir and Freundlich isotherm equations. The maximum biosorption capacities (q max) from the Langmuir equation for copper, lead and cadmium obtained by using Pseudomonas putida were 125, 250 and 333.3 mg metal/g biomass, respectively with high values of correlation coefficients (r 2) 0.95, 0.97 and 0.95, respectively. Biosorpitve mechanism was confirmed by IR analysis and from the identification nature of acidic and basic sites. Moreover, the postulated mechanism was depended mainly on ionic interaction and complex formation. The results demonstrated that the bacterial isolate of Pseudomonas putida could be used as a promising biosorbent for the removal of copper, lead and cadmium ions from aqueous solutions.

- by Dr. Usama Tahoun
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- Microbiology, Biotechnology, Biosorption, Biosorption of heavy metals

In recent years interest in new microbiological methods for wastewaters purification of heavy metal has increased. Cr (VI) sorption was investigated for non-pigmented yeast Saccharomyces cerevisiae 1968, Candida krusei 61t, Williopsis californica 248, pink-pigmented Rhodotorula mucilaginosa 1776, R. aurantiaca 1198, R. aurantiaca 1195, Rhodotorula sp.4 and black yeast Cryptococcus sp. WT. The use of tested yeast as biosorbents for Cr (VI) offers a potential alternative to existing methods for chromium decontamination or recovery from the environment. The sorption isotherms obtained in these experiments for non-living yeast biomass showed that the maximal sorption capacity (Q max) was 1100 and 1000 µmol·(g sorbent)-1 for Rhodotorula sp.4 and R. mucilaginosa 1776, respectively. In the case of living biomass, the highest maximal uptake capacity was found for yeasts C. krusei 61t and W. californica 248. These cultures also demonstrated the high sorption affinity, which makes them especially efficient biosorbents at low concentrations of hexavalent chromium. Some cultures of pigmented yeasts sorbed Cr (VI) better for non-living biomass, than living biomass. In general, non-pigmented yeasts were more tolerant to hexavalent chromium than tested pigmented strains. The high efficiency of hexavalent chromium elution was shown with 0.1N EDTA.

The aim of the present study is to investigate the efficiency of palm leaves activated carbon on the removal of lead (Pb), zinc (Zn), copper (Cu), and cadmium (Cd) from the aqueous solution. The effect of various process parameters such as pH (2 – 10), initial metal ion concentration (50 – 1000 mg/L), particle size (125, 500, 800 μm), and temperature (303, 313, 323 K) was studied using batch adsorption technique. Thermodynamic parameters were also evaluated. The maximum metal ion removal efficiency of 94.5, 94.1, 87.4, and 90.7% for Pb, Cd, Zn, and Cu, respectively, was reached at an optimum pH of 5, biosorbent dosage of 1.0 g, and initial metal ion concentration of 50 ppm. The Freundlich adsorption isotherm model best described the removal of metal ions
on palm leaves activated carbon with high correlation coefficients (0.98 – 1.00). The adsorption process was
found to be favorable since the intensity of adsorption, n lies within 1 to 10. The adsorption capacity values were 40.0, 38.3, 38.0, and 40.00 mg/g for lead (Pb), zinc (Zn), copper (Cu), and cadmium (Cd), respectively. The metal ion adsorption was also found to be endothermic in nature. The efficiency was increased with an increase in temperature implying the process should be performed at a controlled temperature