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1.
Adsorption for heavy metals via biomaterials such as fungal biomass presents a practical remediation technique for polluted water. Among all known filamentous fungi, Penicillium chrysogenum is widespread in nature and can serve as a biosorbent for heavy metals. In the current study, the ability of P. chrysogenum XJ-1 to remove copper (Cu2+) and chromium (Cr6+) from water was evaluated. The maximum biosorption capacity of XJ-1 for Cu2+ reached 42.83 ± 0.57 mg g?1 dry biomass at pH 5.0 after the equilibrium time of 1.5 h. The maximum biosorption capacity for Cr6+ at pH 3.0 reached 52.69 ± 1.68 mg g?1 dry biomass after the equilibrium time of 1.5 h. The biosorption data of XJ-1 biomass were well fitted to the Freundlich isotherm model and the pseudo-second-order Lagergren kinetic model. Laundry powder-treated and HCl-treated XJ-1 biomass significantly enhanced its adsorption capacity to Cu2+ and Cr6+, respectively. HCl and NaOH were suitable desorbents for Cu2+/Cr6+ loading biomass, respectively. Fourier transform infrared spectroscopy analyses revealed that hydroxyl, amine, and sulfonyl groups on the biosorbent contributed to binding Cu2+ and Cr6+ and that carbonyl and carboxyl groups were also vital binding sites of Cu2+. Scanning electron microscopy and energy-dispersive x-ray (SEM-EDX) analyses confirmed that considerable amounts of metals were precipitated on the cell surface of XJ-1. Our results suggested that XJ-1 might be used to purify multimetal-contaminated water. This low-cost and eco-friendly biomass of XJ-1 seems to have a broad use in the restoration of metal-contaminated water.  相似文献   

2.
A fluorescence and absorption chemosensor (SAAT) based on 5-(hydroxymethyl)-salicylaldehyde (SA) and o-aminothiophenol (AT) was designed and synthesized. SAAT in DMSO–HEPES (20.0 mM, v/v, 1:99, pH = 7.0) solution shows a highly selective and sensitive absorption and an ‘on–off’ fluorescence response to Cu2+ ions in aqueous solutions over all other competitive metal ions including Na+, Ag+, Ba2+, Ca2+, Cd2+, Mg2+, Zn2+, Cr3+, Al3+, Hg2+, K+, Mn2+, Ni2+, Sr2+, Tb3+ and Co2+. SAAT exhibits ratiometric absorption sensing ability for Cu2+ ions. Importantly, SAAT also can sense Cu2+ ions using fluorescence quenching, the fluorescence intensity of SAAT showed a good linear relationship with Cu2+ concentration, and the detection limit of Cu2+ was 0.34 μM. The results of Job's plot, Benesi–Hildebrand plot, mass spectra, and density functional theory calculations confirmed that the selective absorption and fluorescence response were attributed to the formation of a 1:1 complex between SAAT and Cu2+. SAAT in test film could identify Cu2+ in water samples using the intuitive fluorescence colour change under a UV lamp. SAAT has great application value as a selective and sensitive chemosensor to discriminate and detect Cu2+ ions.  相似文献   

3.
Macroalgae have received much attention for heavy metal removal in treatment of domestic wastewater. In this report, the uptake capacity of a common freshwater green alga, Cladophora fracta, for heavy metal ions (copper, zinc, cadmium, and mercury) was evaluated. The equilibrium adsorption capacities were 2.388?mg Cu2+, 1.623?mg Zn2+, 0.240?mg Cd2+, and 0.228?mg Hg2+ per gram of living algae at 18°C and pH?5.0. The removal efficiency for Cu2+, Zn2+, Cd2+, and Hg2+ were 99, 85, 97, and 98%, respectively. Greater removal efficiency was achieved when the concentrations of metal ions were at very low level. The results indicated that living algae are suitable for removal and recovery of heavy metal ions from aqueous solutions and can be a potential tool to treat industrial wastewater.  相似文献   

4.
An acidophilic volvocine flagellate, Chlamydomonas acidophila (Volvocales) that was isolated from an acid lake, Katanuma, in Miyagi prefecture, Japan was studied for growth, ultrastructural characterization, and metal tolerance.

Chlamydomonas acidophila is obligately photoautotrophic, and did not grow in the cultures containing acetate or citrate even in the light. The optimum pH for growth was 3.5-4.5. To characterize metal tolerance, the toxic effects of Cd, Co, Cu, and Zn on this alga were also studied. Effective metal concentrations, which limited the growth by 50%, EC50 were measured, after 72h of static exposure. EC50s were 14.4 μM Cd2+, 81.3 μM Co2+, 141μM Cu2+, and 1.16 mM Zn2+ for 72 h of exposure. Thus, this alga had stronger tolerance to these metals than other species in the genus Chlamydomonas.  相似文献   

5.
The present work deals with the biosorption performance of dried and non-growing biomasses of Exiguobacterium sp. ZM-2, isolated from soil contaminated with tannery effluents, for the removal of Cd2+, Ni2+, Cu2+, and Zn2+ from aqueous solution. The metal concentrations studied were 25 mg/l, 50 mg/l, 100 mg/l, 150 mg/l and 200 mg/l. The effect of solution pH and contact time was also studied. The biosorption capacity was significantly altered by pH of the solution. The removal of metal ions was conspicuously rapid; most of the total sorption occurred within 30 min. The sorption data have been analyzed and fitted to the Langmuir and Freundlich isotherm models. The highest Qmax value was found for the biosorption of Cd2+ at 43.5 mg/g in the presence of the non-growing biomass. Recovery of metals (Cd2+, Zn2+, Cu2+ and Ni2+) was found to be better when dried biomass was used in comparison to non-growing biomass. Metal removal through bioaccumulation was determined by growing the bacterial strain in nutrient broth amended with different concentrations of metal ions. This multi-metal resistant isolate could be employed for the removal of heavy metals from spent industrial effluents before discharging them into the environment.  相似文献   

6.
The potential of alginate-immobilized Microcystis packed in a column for maximum removal of Cu2+ at different flow rates, biomass, and initial metal ion concentration was assessed in a continuous flow system. Although Cu2+ removal did occur at all the flow rates tested, it was maximum (54%) at 0.75-ml min−1 flow rate, 30 μg ml−1 initial metal ion concentration and 0.016 g biomass. Cu2+ removal was influenced by inlet metal ion concentration and biomass density. An increase in the biomass concentration from 0.016 to 0.128 g resulted in an apparent increase in percentage removal but the Cu2+ adsorbed per unit dry wt. declined. When the flow rate (0.75 ml min−1) and biomass density (0.064 g) were kept constant and the inlet metal ion concentration was varied from 10 to 150 μg ml−1, a 68% removal of Cu2+ was obtained at 50 μg ml−1 initial concentration in a time duration of 15 min. The metal-laden columns were efficiently desorbed and regenerated following elution with double distilled water (DDW) (pH 2) (89%). This was followed by 1 mm EDTA > 1 mm NTA > 0.1 mm EDTA > 1 mm HCl > 1 mm HNO3 > 5 mm CaCl2 > DDW (pH 7.0) > 1 mm NaHCO3 > 1 mm CaCl2. Of the total (2.83 mg) adsorbed Cu2+, 1.89 mg (67%) was desorbed by DDW (pH 2) within the first 20 min of elution time. Thereafter the desorption rate slowed down and only 22% (0.632 mg) desorption was obtained in the last 20 min. In contrast to water pH 2, the desorption of Cu2+ by 1 mm EDTA was very slow, the maximum being 8% after 40 min of elution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

7.
Complex formation properties of a novel water soluble thiazolyloxime 2-(4-methylthiazol-2-yl)-2-(hydroxyimino)acetic acid (H3L1) with Cu2+ and Ni2+ were investigated in solution by potentiometrical and spectral (UV-Vis, EPR, NMR) methods. All Cu2+ and most of Ni2+ complex species detected in solution were found to have square-planar MN4 core with oxime and heterocyclic nitrogen atoms which was rationalized in terms of destabilizing effect of repulsive interaction between oxygen atom of carboxylic group and nitrogen atom of thiazole ring in N,O-coordinated ligand conformation. It has been found that stability of metal complexes in a series of oxime ligands is dependent upon basicity of nitrogen atom of oxime group. The thiazolyloxime forms less stable complexes with Cu2+ but stronger ones with Ni2+ ions when compared to parent 2-(hydroxyimino)propanoic acid. The lower stability obtained for Cu2+ complexes was elucidated in terms of negative inductive effect of the thiazole and nitrile substituents as well as an effect of intramolecular attractive interaction between thiazolyl sulfur and oxime oxygen atoms in thiazolyloxime. In the case of Ni2+ the complexes formed are square-planar and it is why thiazolyl ligand is more effective in metal ion binding than simple 2-(hydroxyimino)propanoic acid forming only octahedral species. The solid state structure of the Co3+ complex K3[Co(HL1)3]·5.5H2O (1) was studied by X-ray analysis. The thiazolyloxime ligand is coordinated to Co3+ via oxime nitrogen and carboxylate oxygen atoms forming five-membered chelate rings.  相似文献   

8.
Deng L  Zhu X  Wang X  Su Y  Su H 《Biodegradation》2007,18(4):393-402
Biosorption is an effective means of removal of heavy metals from wastewater. In this work the biosorption behavior of Cladophora fascicularis was investigated as a function of pH, amount of biosorbent, initial Cu2+ concentration, temperature, and co-existing ions. Adsorption equilibria were well described by Langmuir isotherm models. The enthalpy change for the biosorption process was found to be 6.86 kJ mol−1 by use of the Langmuir constant b. The biosorption process was found to be rapid in the first 30 min. The presence of co-existing cations such as Na+, K+, Mg2+, and Ca2+ and anions such as chloride, nitrate, sulfate, and acetate did not significantly affect uptake of Cu2+ whereas EDTA substantially affected adsorption of the metal. When experiments were performed with different desorbents the results indicated that EDTA was an efficient desorbent for the recovery of Cu2+ from biomass. IR spectral analysis suggested amido or hydroxy, C=O, and C–O could combine strongly with Cu2+.  相似文献   

9.
Abstract

This study evaluates the biosorption of copper by aerobic biomass that was selected from surface waters of the San Pedro River in Sonora, Mexico. Using a batch system, 73% biosorption of copper was obtained in 75 minutes. Continuous biosorption assays were carried out for 133 days in an ascending flow aerobic reactor packed with zeolite (AFAR-PZ) that was inoculated with a bacterial consortium. Strains were grown until 1g L?1 of biomass was obtained. Tests using continuous biosorption were performed as follows: (i) the addition of 50 mg Cu2+ L?1 without recirculation of biomass; (ii) the addition of 20 mg Cu2+ L?1without recirculation of biomass; and (iii) the biomass were recirculated with the addition of 20 mg Cu2+ L?1 to pH 3 to 4. The fourth and fifth assays varied pH between 4 and 5, with 20 mg Cu2+ L?1and the biomass recirculated. Biosorption capacity of the first and second assays was 96% on the first day of experimentation. During the third trial 97% of biosorption was obtained during 6 days and the process was improved by varying the pH. Copper biosorption equilibrium was investigated under the same operating conditions. Langmuir adsorption isotherms were used to fit experimental data. The biosorption capacity of aerobic biomass was 3.08 mmol g?1. It was demonstrated that this biomass is capable of biosorbing copper and this method has potential for the treatment of industrial effluents contaminated with heavy metals.  相似文献   

10.
An industrial strain of Saccharomyces cerevisiae collected from the waste of a brewing industry was used to remove lead, cadmium and copper from aqueous solutions (1?mm). Metal removal efficiency by using either biomass suspension directly diluted into the metal solutions or biomass previously incubated and washed in distilled water was compared. In all experiments with unwashed biomass a shift in the medium pH from 4.5 to a final value in the 7.0–8.0 range occurred. This pH increase was responsible for a metal precipitation effect associated to the metal biosorption. A very different pH profile was observed when washed biomass was used leading to different removal profiles for Cd2+ and Pb2+ and a similar one for Cu2+. In the absence of biomass, medium components and/or the excreted intracellular products proved to interfere in the metal removal and to be responsible for 80% Pb2+ precipitation, in the pH 4.5–5.0 range. To initial metal solution pH, leading to the lowest residual ion concentrations, after 96?h of contact with unwashed biomass and in the absence of pH adjustment, was 4.5–5.0. Continuous or stepwise adjustment of medium pH to this range during the process was unfavourable for metal removal, being the continuous adjustment the worst procedure. In this case, Cd2+ was not biosorbed and Cu2+ removal decreased from 76 to 33%. However, Pb2+ was always extensively removed (89%) and only slightly affected by pH control. The global results suggest different removal mechanisms for each cation. Cu2+ was removed by both metal sorption and precipitation, due to the pH shift that occurred during the process, while Cd2+ removal showed to be completely dependent of this pH shift. Pb2+ was totally and quickly removed, by precipitation, in the presence of the biomass suspension and at pH 4.5. Moreover, the biosorbent changes occurring during the process played an important role in the metal removal when non-viable microbial biomass is used.  相似文献   

11.
Biosorption of copper by Sargassum fluitans biomass in fixed-bed column   总被引:1,自引:0,他引:1  
Summary The behavior of native and protonated Sargassum fluitans seaweed biomass packed in a fixed-bed was examined during a continuous removal of Cu2+ from 35 mg/L aqueous solution at pH 5.0. The capacity of native and protonated biomass, based on the dry weight of the native biomass, were determined to be 61.5 and 54.1 mg/g, respectively. During the saturation of the native biomass with heavy metal, first Na+ and K+, followed by Mg2+ and Ca2+, were eluted from the fixed-bed before the breakthrough time of the Cu2+. The pressure drop across the column varied with the ionic composition of the effluent from the bed, yielding an average permeability coefficient of 2.7 .10-12m2. The void fraction of the interstices in the bed was estimated to be 0.27. No light metals were eluted from the column containing protonated biomass, and the pressure drop remained constant throughout the saturation.  相似文献   

12.
Uptake of Metal Ions by Rhizopus arrhizus Biomass   总被引:10,自引:1,他引:9       下载免费PDF全文
Rhizopus arrhizus biomass was found to absorb a variety of different metal cations and anions but did not absorb alkali metal ions. The amount of uptake of the cations was directly related to ionic radii of La3+, Mn2+, Cu2+, Zn2+, Cd2+, Ba2+, Hg2+, Pb2+, UO22+, and Ag+. The uptake of all the cations is consistent with absorption of the metals by sites in the biomass containing phosphate, carboxylate, and other functional groups. The uptake of the molybdate and vanadate anions was strongly pH dependent, and it is proposed that the uptake mechanism involves electrostatic attraction to positively charged functional groups.  相似文献   

13.
1 Summary Cu2+ adsorbs onto modified bone gelatin beads as a function of pH. The amount of Cu2+ adsorbed is similar to that which has been shown to be adsorb onto other biological materials including bacterial biomass. Langmuir adsorption isotherms were fitted to this data and both the asymptotic maximum solid-phase concentration and the equilibrium constant for these isotherms are presented as a function of the solution pH. The adsorption rate for a typical set of experimental conditions is presented.Research supported by the Office of Basic Energy Scineces, Divisions of Engineering and Geosciences. U.S. Department of Energy under contract DE-AC05-84OR21400 with Martin Marietta Energy Systens, Inc.  相似文献   

14.
Oscillatoria anguistissima rapidly adsorbs Cu2+ from aqueous solution. The adsorption of Cu2+ followed Freundlich Isotherm, and the amount of Cu2+ removed from solution increased with increasing Cu2+ concentration. The adsorption is pH dependent, and maximum Cu2+ removal occurs at pH 5. Of the various pretreatments, HCl treatment of the biomass increased the capacity for Cu2+ removal. Presence of Mg2+ and Ca2+ resulted in decline in the Cu2+ adsorption capacity of Oscillatoria cells. This species could also effectively remove Cu2+ from mine water containing 68.4 μg/ml of Cu2+ at pH 3.45. Received: 23 December 1996 / Accepted: 20 February 1997  相似文献   

15.
Yeast cells are capable of accumulation of various heavy metals, preferentially accumulating those of potential toxicity and also those of value. They retain their ability to accumulate heavy metals under a wide range of ambient conditions. In the present study it was shown that yeast cells in suspension accumulate heavy metal cations such as Cu2+, Co2+. The level of copper accumulation was dependent on the ambient metal concentration and was markedly inhibited by extremes of ambient pH. Temperature (5–40°C) and the presence of the alkali metal sodium had much smaller effects on the level of copper accumulation. This suggests that in waste-waters of pH 5.0–9.0, yeast biomass could provide an effective bioaccumlator for removal and/or recovery of the metal. During bioaccumulation and subsequent processes it is necessary to retain the biomass. It was shown in the present study that this could be achieved by cell immobilization. Immobilization allowed for complete removal of Cu2+, Co2+, and Cd2+ from synthetic metal solutions. The immobilized material could be freed of metals by use of the chelating agent ethylenediamine tetraacetic acid (EDTA) and recycled for further bioaccumulation events with little loss of accumulation capacity.Correspondence to: J. R. Duncan  相似文献   

16.
Heavy metal ions (Pb2+, Cd2+, Mn2+, Cu2+, and Cr2O7 2?) were biosorbed by brown seaweeds (Hizikia fusiformis, Laminaria japonica, and Undaria pinnatifida) collected from the southern coast of South Korea. The biosorption of heavy metal ions was pH-dependent showing a minimum absorption at pH 2 and a maximum biosorption at pH 4 (Pb2+, Cd2+, Mn2+, and Cr2O7 2?) or pH 6 (Cu2+). Biosorption increased most noticeably for pH changes from 2 to 3. In the latter pH range, biosorption increased, because a higher pH decreased the electrostatic repulsion between metal ions and functional groups on the seaweed. In the pH range of 2 ~ 4, biosorption of negatively-charged chromium species (Cr2O7 ?2) followed the pattern of positively-charged metal ions (Pb2+, Cd2+, Mn2+, and Cu2+). This suggests that the most prevalent chromium species were positively-charged Cr3+, reduced from Cr6+ in Cr2O7 ?2. Whereas positively-charged heavy metal ions (Pb2+, Cd2+, Mn2+, and Cu2+) reached a plateau after the maximum level, biosorption of chromium ions decreased noticeably between pH 5 and 8. Kinetic data showed that biosorption by brown seaweed occurred rapidly during the first 10 min, and most of the heavy metals were bound to the seaweed within 30 min. Equilibrium adsorption data for a lead ion could fit well in the Langmuir and Freundlich isotherm models with regression coefficients (R 2) between 0.93 and 0.98.  相似文献   

17.
ABSTRACT

Two strains of thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus, were employed to investigate the biosorption of heavy metals including Cd2+, Cu2+, Co2+, and Mn2+ ions. The effects of different biosorption parameters such as pH (2.0–10.0), initial metal concentrations (10.0–300.0 mg L?1), amount of biomass (0.25–10 g L?1), temperature (30–80°C), and contact time (15–120 min) were investigated. Concentrations of metal ions were determined by using an inductively coupled plasma optical emission spectrometry (ICP-OES). Optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption by Geobacillus thermantarcticus were found to be 4.0, 4.0, 5.0, and 6.0, respectively. For Anoxybacillus amylolyticus, the optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption were found to be 5.0, 4.0, 5.0, and 6.0, respectively. The Cd2+, Cu2+, Co2+, and Mn2+ removals at 50 mg L?1 in 60 min by 50 mg dried cells of Geobacillus thermantarcticus were 85.4%, 46.3%, 43.6%, and 65.1%, respectively, whereas 74.1%, 39.8%, 35.1%, and 36.6%, respectively, for Anoxybacillus amylolyticus. The optimum temperatures for heavy metal biosorption were near the optimum growth temperatures for both strains. Scatchard plot analysis was employed to obtain more compact information about the interaction between metal ions and biosorbents. The plot results were further studied to determine if they fit Langmuir and Freundlich models.  相似文献   

18.
The biosorption of Cu2+ by free and poly acrylamide gel (PAG) immobilized Spirulina platensis (SpiSORB) was characterized under batch and continuous packed bed columnar reaction systems. The biosorption of Cu2+ was shown to be highest at pH of 6.0 for both types of biomass. The PAG immobilization process did not interfere with the Cu2+ binding sites present on biomass leading to cent percent (ca. 250 mg g−1 of dry biomass) retention of biosorption as compared to free cells. Transmission electron microscopy on Cu2+ localization revealed that majority of metal is being sequestered by the cell wall only. The infrared spectrum of metal treated S. platensis biomass indicated the possible involvement of amide, amino, and carboxyl groups in metal binding. Up-flow packed bed columnar reactor containing 2.0 g of PAG immobilized S. platensis shown a maximum of 143-fold volume reduction factor at the residence time of 4.6 min for Cu2+ alone and found to decrease dramatically when Zn2+ is present in a bimetallic solution.  相似文献   

19.
This work describes the preparation of new chelating materials derived from cellulose and sugarcane bagasse for adsorption of Cu2+, Cd2+, and Pb2+ ions from aqueous solutions. The first part involved the mercerization treatment of cellulose and sugarcane bagasse with NaOH 5 mol/L. Non- and mercerized cellulose and sugarcane bagasse were then reacted with ethylenediaminetetraacetic dianhydride (EDTAD) in order to prepare different chelating materials. These materials were characterized by mass percent gain, X-ray diffraction, FTIR, and elemental analysis. The second part consisted of evaluating the adsorption capacity of these modified materials for Cu2+, Cd2+, and Pb2+ ions from aqueous single metal solutions, whose concentration was determined by atomic absorption spectroscopy. These materials showed maximum adsorption capacities for Cu2+, Cd2+, and Pb2+ ions ranging from 38.8 to 92.6 mg/g, 87.7 to 149.0 mg/g, and 192.0 to 333.0 mg/g, respectively. The modified mercerized materials showed larger maximum adsorption capacities than modified non-mercerized materials.  相似文献   

20.
The effects of Cu2+ on growth, chlorophyll and other ion contents ofKoeleria splendens originated from Cu-contaminated soil have been investigated in nutrient solution. The most evident Cu2+ effects concern the root growth, especially the root length. Since in plants grown under lower Cu2+ concentrations (4 and 8 μM) root elongation, biomass, chlorophyll, Mg2+, Fe2+, Ca2+ and K+ content were increased compared with the control, the development of an adaptive mechanism ofK. splendens to Cu2+ is suggested. High Cu2+ concentration (160 μM) caused a significant reduction in root length and biomass as well as a decreased rate of chlorophyll biosynthesis. The reduction of growth can be correlated with the toxic effect of Cu2+ on photosynthesis, root respiration and protein synthesis in roots. 160 μM Cu2+-treatment had a negative influence on the concentrations of Ca2+, Fe2+, Mg2+ and K+ and a positive influence on the Cu2+ concentration in the plant tissues. Loss of nutrients similar to the senescence response suggests that excess of Cu2+ leads to the progressive senescence of the plants. Our results demonstrate the existence of an adaptive mechanism ofK. splendens under low Cu2+ concentrations, while high Cu2+ quantities cause disturbances in plant function.  相似文献   

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