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1.
Crosslinking carboxymethyl starch (CCMS) powder of degree of substitution (DS) 0.43–0.59 was prepared by the process of two
steps of alkali addition synthesis. The technique of powder coupling with ultrafiltration was used to absorb Cu2+, Zn2+, Ni2+, Pb2+, and Cd2+ from aqueous solutions. FTIR was used to demonstrate the successfully grafting of carboxymethyl groups, and the technique
of microwave plasma torch atomic emission spectrometer was applied in rapid determination of the aforementioned heavy metals
ions. The results revealed that the removal sequence of heavy metal ions followed the order of Pb2+>Cu2+>Cd2+>Zn2+>Ni2+. By assistant of diethylene triamine penlaacetic acid, the quaternary system of Pb2+/Ni 2+/Cd2+/Cu2+ mixture solution could have the ideal separation. Besides, the influence of pH, ζ potential, DS value, and membranes molecular
weight cut-off on removal of 20 mg L−1 Pb2+ or Ni2+ was also investigated. 相似文献
2.
Effect of the particle-size distribution on the adsorption of copper, lead, and zinc by Chernozemic soils of Rostov oblast 总被引：1，自引：0，他引：1
T. M. Minkina D. L. Pinskii S. S. Mandzhieva E. M. Antonenko S. N. Sushkova 《Eurasian Soil Science》2011,44(11):1193-1200
The parameters of adsorption of Cu2+, Pb2+, and Zn2+ cations by soils and their particle-size fractions were studied. The adsorption of metals by soils and the strength of their
fixation on the surface of soil particles under both mono- and polyelement contamination decreased with the decreasing proportion
of fine fractions in the soil. The adsorption capacity of the Lower Don chernozems for Cu2+, Pb2+, and Zn2+ depending on the particle-size distribution decreased in the following sequence: clay loamy ordinary chernozem ∼ clay loamy
southern chernozem > loamy southern chernozem > loamy sandy southern chernozem. According to the parameters of the adsorption
by the different particle-size fractions (C
max and k), the heavy metal cations form a sequence analogous to that obtained for the entire soils: Cu2+ ≥ Pb2+ > Zn2+. The parameters of the heavy metal adsorption by similar particle-size fractions separated from different soils decreased
in the following order: clay loamy chernozem > loamy chernozem > loamy sandy chernozem. The analysis of the changes in the
parameters of the Cu2+, Pb2+, and Zn2+ adsorption by soils and their particlesize fractions showed that the extensive adsorption characteristic, namely, the maximum
adsorption (C
max), was a less sensitive parameter characterizing the soil than the intensive characteristic of the process—the adsorption
equilibrium constant (k). 相似文献
3.
Toshiyuki Wakatsuki Hisao Furukawa Keizaburo Kawaguchi 《Soil Science and Plant Nutrition》2013,59(4):351-360
The authors reported that the relative bonding strength between ligand of soil colloid surface and cations could be obtained easily by the measurement of MCSA, and that the MCSA corresponded to the constant of Langmuir's adsorption isotherm equation. The relative bonding strength of cations with respect to kaolinitic soil clay at pH 6 was, Cr3+>Fe3+, Al3+>Ga8+>Cu8+>Pb2+>Y3+, La3+>Mn2+>Ni2+, Co2+> Zn2+>Sr2+, Mg2+>NH4+, K+, and with respect to colloid with humus coating, Y3+, La3+>Pb2+>Cu2+, and the other orders were same. The solubility of cations in soil colloid aqueous dispersion system was calculated from the values of MCSAs, and considered as follows, Y3+, La3+, Cu3+, Pb3+, Mn2+, Ni2+, CO2+: concentration in soil solution and soil geochemical mobility may be regulated by the specific adsorption reaction, Zn2+, Mg2+, Sr2+, K+, NH4+: concentration in soil solution and soil geochemical mobility may be regulated by the non-specific adsorption reaction, but at neutral to alkaline condition, Zn2+ and Mg2+ may specifically adsorb on soil, clays, Fe3+, Cr3+, Al3+, Ga3+: concentration in soil solution and soil geochemical mobility may be regulated by the solubility of their oxide hydrates. 相似文献
4.
5.
重金属和pH值对类芦种子萌发的影响 总被引：3，自引：0，他引：3
类芦(Neyraudia reynaudiana)是一种具有极强耐干旱、贫瘠、高温等逆境的多年生禾草植物,是南方水蚀荒漠化地区、采矿采石厂及各类边坡植被自然恢复中的先锋植物。为探索在各类矿区及受重金属污染的地区采用类芦进行生态修复的可行性,通过室内发芽试验,对类芦种子在Hg2+,Cr6+,Cd2+,Pb2+,Zn2+,Cu2+等6种重金属离子胁迫及不同pH值条件下的萌发能力进行了研究。结果表明,类芦种子在pH值为5.0~9.0的范围内具有良好的萌发能力;6种重金属离子随着处理浓度的升高,对类芦种子的抑制作用逐渐加强,且出现显著抑制作用的最低浓度顺序为:Cd2+Cu2+Hg2+,Zn2+,Cr6+Pb2+;6种重金属对类芦种子活力指数出现显著影响的浓度均较显著影响发芽率、发芽势和发芽指数3个指标的浓度低,说明类芦幼苗生长比种子萌发对6种重金属更加敏感。 相似文献
6.
The equilibria as well as the rates of adsorption and desorption of the ions Pb2+, Cu2+, Cd2+, Zn2+, and Ca2+ by soil organic matter were determined in batch experiments as a function of the amount of metal ions added to an aqueous suspension of HCl-washed peat. Simultaneous determination of the metal ions and hydrogen ions in the solution by atomic absorption spectrophotometry and pH-measurements showed that the adsorption of one divalent metal ion by peat was coupled with the release of two hydrogen ions. Since this equivalent ion-exchange process causes a corresponding increase of the electric conductivity of the solution, the rates of the adsorption and desorption processes were determined by an immersed conductivity electrode. The distribution coefficients show that the selective order for the metal adsorption by peat is Pb2+ > Cu2+ > Cd2+≌ Zn2+ > Ca2+ in the pH range of 3·5 to 4·5. The slope of -2, as observed in a double logarithmic plot of the distribution coefficients versus the total solution concentration confirms the equivalence of the ion-exchange process of divalent metal ions for monovalent H3O+ -ions in peat. The absolute rates of adsorption, as well as the rates for the fractional attainment of the equilibrium, increase with increasing amounts of metal ions added. This behaviour is also observed for the subsequent desorption of the metal ions by H3O+-ions. At a given amount of metal ions added, the absolute rates of adsorption decrease in the order Pb2+ > Cu2+ > Cd2+ > Zn2+ > Ca2+, while the rates for the fractional attainment of the equilibrium decrease in the order Ca2+ > Zn2+≌ Cd2+ > Pb2+ > Cu2+. The half times for adsorption and desorption were in the range of 5 to 15 sec. 相似文献
7.
《Communications in Soil Science and Plant Analysis》2012,43(9-10):1129-1144
Abstract To investigate the activity of free cadmium (Cd2+), copper (Cu2+), lead (Pb2+), and zinc (Zn2+) ions and analyze their dependence on pH and other soil properties, ten contaminated soils were sampled and analyzed for total contents of Cd, Cu, Pb, and Zn (CdT, CuT, PbT, and ZnT, respectively), 0.43 MHNO3‐extractable Cd, Cu, Pb, and Zn (CdN, CuN, PbN, and ZnN, respectively), pH, dissolved organic matter (DOC), cation exchange capacity (CEC), ammonium oxalate extractable aluminum (Al) and iron (Fe), and dissolved calcium [Ca2+]. The activity of free Pb2+, Cd2+, Cu2+, and Zn2+ ions in soil solutions was determined using Donnan equilibrium/graphite furnace atomic absorption (DE/GFAA). The solubility of Cd in soils varied from 0.16 to 0.94 μg L‐1, Cu from 3.43 to 7.42 μg L‐1, Pb from 1.23 to 5.8 μg L‐1, and Zn from 24.5 to 34.3 μg L‐. In saturation soil extracts, the activity of free Cd2+ ions constituted 42 to 82% of the dissolved fraction, for Cu2+the range was 0.1 to 7.8%, for Pb2+ 0.1 to 5.1% and for Zn2+2 to 72%. The principal species of Cd, Cu, Pb, and Zn in the soil solution is free metal ions and hydrolyzed ions. Soil pH displayed a pronounced effect on the activity of free Cd2+, Cu2t, Pb2+, and Zn2+ ions. 相似文献
8.
Isotherms of mono- and polyelement adsorption of Cu2+, Pb2+, and Zn2+ by an ordinary chernozem were described by the Langmuir equation. The values of the adsorption constant k decreased in the range Cu2+ > Pb2+ ≫ Zn2+ for the monoelement adsorption from nitrate and acetate salt solutions, Cu2+ > Pb2+ > Zn2+ for the polyelement adsorption from nitrate solutions, and Pb2+ > Cu2+ ≫ Zn2+ for the polyelement adsorption from acetate solutions. The maximum adsorption (C
max, ∞) of individual cations at the polyelement contamination was always lower than at the monoelement contamination because of
the mutual competition. At the same time, the values of k for the polyelement adsorption were higher than those for the monoelement adsorption because heavy metals (HMs) interact
with most of the specific adsorption centers. It was shown that the ratio between the content of exchangeable cations displaced
from the soil exchangeable complex (SEC) into the solution and the content of adsorbed HMs decreased with the increasing concentration
of adsorbed HMs. These values could be higher (for Cu2+), equal, or lower than 1 (for Pb2+ and Zn2+). In the former case, this was due to the dissolution of readily soluble salts at low HM concentrations in the SEC. In the
latter case, this was related to the adsorption of associated HMs and the formation of new phases localized on the surface
of soil particles at high HM concentrations in the SEC. 相似文献
9.
Inorganic pyrophosphatase activity in three soils decreased when exchangeable and soluble metals were removed by leaching with in NH4OAc (pH 8). The effect of added metal ions at various concentrations in the leached soils showed that, at certain concentrations, Ba2+, Ca2+, Co2+, Mg2+, Mn2+, Ni2+ and Zn2+ promoted, K+ and Na+ had no effect, and Fc2+ and Cu2+ decreased pyrophosphatase activity. At high concentrations (>50 mM). Co2+, Mn2+, Ni2+ and Zn2+ inhibited pyrophosphatase activity in two soils. The concentration of metal ion needed for optimum activity of pyrophosphatase varied among the soils. The efficiency of the metal ions at optimum concentrations (average percentage increase for three soils in parentheses) in promoting pyrophosphatase was Ca2+ (47) > Mg2+ (42) > Ba2+ = Co2+ (29) > Ni2+ (27) > Zn2+ (20) > Mn2+(16). Pyrophosphatase activity in two leached soils adjusted to 50, 75, 100 or 150 mM PPi and Ca2+ or Mg2+ concentrations from 0 to 250 mM was at an optimum when the metal ion: PPi ratio was 1:1. Soil pyrophosphatase in the presence of 200 mM CaCl2 or MgCl2 was protected against inactivation by heat (90 C for up to 30 min). 相似文献
10.
Chun Yang Yin Mohamed Kheireddine Aroua Wan Mohd Ashri Wan Daud 《Water, air, and soil pollution》2008,192(1-4):337-348
In this study, palm shell activated carbon was impregnated with polyethyleneimine (PEI) and the effect of impregnation on batch adsorption of Ni2+, Cd2+or Pb2+ as well as the equilibrium behavior of adsorption of metal ions on PEI-impregnated AC were investigated. PEI impregnation evidently increased the single metal adsorption capacities of Ni2+ or Cd2+except for Pb2+, where its adsorption capacities were reduced by 16.67% and 19.55% for initial solution pH of 3 and 5 respectively. This suggested that PEI-impregnated AC could be used for selective separation of Pb2+ ions from other metal ions. The adsorption data of all the metal ions on both virgin and PEI-impregnated AC for both initial solution pH of 3 and 5 generally fitted the Langmuir and Redlich-Peterson isotherms considerably better than the Freundlich isotherm. 相似文献
11.
《Communications in Soil Science and Plant Analysis》2012,43(21-22):3252-3262
The adsorption of heavy metals [cadmium (Cd 2+), cobalt (Co2+), nickel (Ni2+), zinc (Zn2+), and lead (Pb)] and calcium (Ca2+) on humic acid and silica were investigated to understand the adsorptive selectivities of heavy metals on the constituents of soil. The experiments for the adsorption of Cd and Pb were carried out in a 0.1 mol L?1 (M) sodium nitrate (NaNO3) background solution, whereas those for the other metals were done in a 0.1 M sodium chloride (NaCl) solution. The adsorptive affinities of the metal ions on the humic acid and silica were ranked by the intrinsic surface complexation constants [K m 1(int)] that were calculated approximately from the adsorptive data using a constant capacitance model. The log [K m 1(int)] values of the metals were in the order Zn2+(?2.29) > Cd2+(?2.41) > Co2+(?2.74) > Ni2+(?2.92) ?> Ca2+ (?3.33) for the humic acid and Zn2+(?4.23) > Cd2+(?4.49) > Ni2+(?4.51) ? Co2+ (?5.99) > Ca2+(?6.37) for silica. 相似文献
12.
D. L. Pinskii T. M. Minkina S. S. Mandzhieva Yu. A. Fedorov T. V. Bauer D. G. Nevidomskaya 《Eurasian Soil Science》2014,47(1):10-17
The effect of Cl?,SO 4 2? , CH3COO?, and NO 3 ? anions on the adsorption of copper, lead, and zinc by an ordinary chernozem has been studied. The effect of the anions on the adsorption of Cu2+, Pb2+, Zn2+ ions is significant but uncertain. It has been shown that the attendant anions affect the shape of the adsorption isotherms, which are described by the Langmuir, Freundlich, or Henri equations. The constants of the adsorption from a nitrate solution calculated from the Langmuir equation (K L) decrease in the following order: Cu2+ > Pb2+ >> Zn2+. The values of the maximum adsorption (C max) decrease in the following order: Cu2+ ≥ Zn2+ > Pb2+ for acetate solutions and in the series Pb2+ > Zn2+ ≥ Cu2+ for nitrate solutions. The values of the Henry constants (K H) calculated for the adsorption of the same cations from chloride solutions decrease in the same order as the values of K L. The CH3COO? anion has the highest effect on the constant values. The NO 3 ? and Cl? anions “switch their places” depending on the attendant cation, but their effect is always lower than that of the acetate anion. The values of C max for copper and zinc are most affected by the CH3COO? anion, and the adsorption of zinc is most affected by the Cl? and NO 3 ? anions. The assessment of the mobility of the adsorbed cations from the extraction with ammonium acetate (pH 4.8) has shown that the content of the desorbed metals is always lower than the content of the adsorbed cations and varies from 0.025 to 83%. According to their mobility, the adsorbed metals form the following order: Zn2+ > Pb2+ > Cu2+. The effect of the attendant anions on the extractability of the adsorbed cations decreases in the following order: chlorides > sulfates > acetates > nitrates. 相似文献
13.
The metal complexing properties of the colloidal and non-colloidal fractions of water extracts of peat and aerobically composted lucerne, and of chelating resin and alkali extracts of peat and soil organic matter were compared. The contributions of the non-colloidal fractions to the complexing properties of the whole extracts are considerable, and on a weight-for-weight basis are somewhat greater than that of the corresponding colloidal material. No one compound is preponderantly responsible for the complexing action. The complexing activity of the non-colloidal fractions is confined almost entirely to the acidic constituents. On the basis of the enhancement of the visible range of optical absorbance of the various preparations, Cu2+ is more extensively complexed than Mg2+, Mn2+, Cd2+, Zn2+, Co2+, Ni2+, and Pb2+. 相似文献
14.
The adsorption capacity of seven inorganic solid wastes [air-cooled blast furnace (BF) slag, water-quenched BF slag, steel furnace slag, coal fly ash, coal bottom ash, water treatment (alum) sludge and seawater-neutralized red mud] for Cd2+, Cu2+, Pb2+, Zn2+ and Cr3+ was determined at two metal concentrations (10 and 100 mg?L?1) and three equilibrium pH values (4.0, 6.0 and 8.0) in batch adsorption experiments. All materials had the ability to remove metal cations from aqueous solution (fly and bottom ash were the least effective), their relative abilities were partially pH dependant and adsorption increased greatly with increasing pH. At equimolar concentrations of added metal, the magnitude of sorption at pH 6.0 followed the general order: Cr3+????Pb2+????Cu2+?>?Zn2+?=?Cd2+. The amounts of previously sorbed Pb and Cd desorbed in 0.01 M NaNO3 electrolyte were very small, but those removed with 0.01 M HNO3, and more particularly 0.10 M HNO3, were substantial. Water treatment sludge was shown to maintain its Pb and Cd adsorption capability (pH 6.0) over eight successive cycles of adsorption/regeneration using 0.10 M HNO3 as a regenerating agent. By contrast, for BF slag and red mud, there was a very pronounced decline in adsorption of both Pb and Cd after only one regeneration cycle. A comparison of Pb and Cd adsorption isotherms at pH 6.0 for untreated and acid-pre-treated materials confirmed that for water treatment sludge acid pre-treatment had no significant effect, but for BF slag and red mud, adsorption was greatly reduced. This was explained in terms of residual surface alkalinity being the key factor contributing to the high adsorption capability of the latter two materials, and acid pre-treatment results in neutralization of much of this alkalinity. It was concluded that acid is not a suitable regenerating agent for slags and red mud and that further research and development with water treatment sludge as a metal adsorbent are warranted. 相似文献
15.
Purpose
TiO2 photocatalytic degradation of tetracycline (TC) in aqueous solution under UV irradiation was investigated as affected by different environmental factors, including cations, anions, organic acids, and surfactants.Materials and methods
The solution of TC with TiO2 was irradiated by medium mercury lamp. The concentrations of TC and metal ions were analyzed by HPLC and AAS, respectively. The degradation efficiency of TC was calculated based on TC disappearance.Results and discussion
Photocatalysis was very effective for TC removal. The degradation efficiency of TC was significantly enhanced in the presence of Cu2+/Pb2+, SO4 2?/Cl?, and humic acid (HA) in the examined range, but did no change with Ni2+, Cd2+, or Zn2+. In addition, the results also showed that solution Cu2+ and Pb2+ ions could be reduced during the process, while Ni2+, Cd2+, and Zn2+ were still kept in the solution. However, tannic acid (TA), gallic acid (GA), citric acid (CA), salicylic acid (SA), hydroxypropyl-β-cyclodextrin (HPCD), polyoxyethylene lauryl ether (Brij35), or polyoxyethylenesorbitan monooleate (Tween80) significantly decreased the degradation efficiency of TC.Conclusions
The photocatalytic approach could be successfully applied to remove TC, and environmental factors significantly influenced its degradation efficiency. It would be useful to understand the environmental behaviors of TC and for the implementation of remediation strategies of TC. 相似文献16.
Violante Antonio Ricciardella Mariarosaria Pigna Massimo 《Water, air, and soil pollution》2003,145(1-4):289-306
A study was carried out on the adsorption of Co2+, Cu2+, Pb2+, and Zn2+ ions on mixed Fe-Al oxides inthe absence or presence of increasing concentrations of oxalate or tartrate. Mixed Fe-Al oxides were prepared by precipitating at pH 5.5 mixtures of Fe and Al ions at initial Fe/Al molar ratios (R) of 0, 1, 2, 4, 10 and ∞ (R0, R1, R2, R4, R10 and R∞).The oxides aged 7 days at 20 °C or 30 days at 50 °C showed different chemical composition and physico-chemical and mineralogical properties. All the mixed Fe-Al oxides showed presence of poorly crystalline materials (ferrihydrite) even after prolonged aging. The heavy metals wereselectively adsorbed on the oxides. For all the precipitates aged7 days at 20 °C, the selectivity sequence wasPb2+> Cu2+ > Zn2+ > Co2+, but the pH at which 50% ofeach cation was adsorbed (pH50) was different from sample tosample. It was found that usually the greater the amounts of Fe in Fe-Al gels the lower the pH50 for each metal, but the adsorption of a heavy metal was not linearly related to Fe content. The pH50 usually did not change significantly when the oxides were aged 30 days at 50 °C. Competitive adsorption of Cu and Zn on ferrihydrite (R∞) showed thatCu strongly prevented Zn adsorption even at an initial Zn/Cu molar ratio of 8, whereas Cu sorption was not inhibited. In thepresence of oxalate (OX) or tartrate (TR) (organic ligand/Pb molar ratio (rL) from 0 to 7) the quantities of Pb adsorbedon the Fe-Al oxides usually increased with increasing rL. The adsorption increase of Pb was particularly high on the oxidesricher in Fe (R4-R∞), but a significant increase was also observed on R0-R2 samples. The adsorption of Pb on the oxides hasbeen influenced not only by the presence and concentration of organic ligands but also by the sequence of addition of Pb and tartrate on the sorbents. It has been ascertained that on each oxide the greater amounts of Pb were adsorbed when tartrate wasadded before Pb and usually according to the following sequence: Tr before Pb > Pb before Tr > Pb + Tr > Pb. 相似文献
17.
Ángeles Val del Río Tulio da Silva Tiago Henrique Martins Eugenio Foresti José Luis Campos Ramón Méndez Anuska Mosquera-Corral 《Water, air, and soil pollution》2017,228(11):439
The inhibitory effect of seven different metals on the specific anammox activity of granular biomass, collected from a single stage partial nitritation/anammox reactor, was evaluated. The concentration of each metal that led to a 50% inhibition concentration (IC50) was 19.3 mg Cu+2/L, 26.9 mg Cr+2/L, 45.6 mg Pb+2/L, 59.1 mg Zn+2/L, 69.2 mg Ni+2/L, 174.6 mg Cd+2/L, and 175.8 mg Mn+2/L. In experiments performed with granules mechanically disintegrated (flocculent-like sludge), the IC50 for Cd+2 corresponded to a concentration of 93.1 mg Cd+2/L. These results indicate that the granular structure might act as a physical barrier to protect anammox bacteria from toxics. Furthermore, the presence of an external layer of ammonia oxidizing bacteria seems to mitigate the inhibitory effect of the metals, as the values of IC50 obtained in this study for anammox activity were higher than those previously reported for anammox granules. Additionally, the results obtained confirmed that copper is one of the most inhibitory metals for anammox activity and revealed that chromium, scarcely studied yet, has a similar potential inhibitory effect. 相似文献
18.
M.A. Tabatabai 《Soil biology & biochemistry》1977,9(1):9-13
Disposal of sewage sludges and effluents on agricultural land is becoming a widespread practice. Most sludge samples disposed on soils contain large quantities of various trace elements. Studies of 20 trace elements commonly found in sludge samples showed that they inhibit the activity of urease in soils and that their order of effectiveness as inhibitors of urease depends on the soil. When the trace elements were compared by using 5 μmiol·g?1 soil, however, some of them showed the same order of effectiveness as urease inhibitors in the six soils studied i.e., for the monovalent and divalent ions, Ag+ ≥ Hg2+ >Cu2+ >Cd2+ >Zn2+ >Sn2+ >Mn2+, and generally, Fe2+ >Fe2+andCu2+ >Cu+. Other trace element ions that inhibited urease were Ni2+, Co2+, Pb2+, Ba2+, As3+ B3+, Cr3+, Al3+. V4+ Se4+ and Mo6+. Of the trace element ions studied, only As5+ and W6+ did not inhibit urease activity in soils.Studies on the distribution of urease activity showed that it is concentrated in surface soils and decreases with depth. Urease activity was proportional to organic C distribution in each soil profile and was significantly correlated with organic C in the surface soils studied. 相似文献
19.
Combined Removal of Zinc (II) and Cadmium (II) from Aqueous Solutions by Adsorption onto High-Calcium Turkish Fly Ash 总被引：1，自引：0，他引：1
The aim of this work is the investigation of possible use of flyash in the removal of zinc (Zn2+) and cadmium (Cd2+) contained in aqueous solutions. Batch adsorption experiments wereperformed in order to evaluate the removal efficiency oflignite-based fly ash. The parameters studied include contact time, pH,temperature, initial concentration of the adsorbate and fly ashdosage. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 7.0 to 7.5. The percent adsorption of Zn2+ and Cd2+ increased with an increase in concentration of Zn2+ and Cd2+, dosage of fly ash and temperature. Theapplicability of Langmuir isotherm suggests the formation ofmonolayer coverage Zn2+ and Cd2+ ions at the outer surface of the adsorbent. Thermodynamic parameters suggested the endothermic nature of the adsorption process. The fly ashwas found to be an metal adsorbent as effective as activated carbon. 相似文献
20.
Sandra Grujić Sava Vasić Ivana Radojević Ljiljana Čomić Aleksandar Ostojić 《Water, air, and soil pollution》2017,228(2):73
This study compares the effect of heavy metals (Hg2+, Cu2+, and Pb2+) on the Rhodotorula mucilaginosa and Saccharomyces boulardii biofilm and planktonic cells. A MBECTM-HTP assay was used to test the levels of tolerance to heavy metals. The minimum inhibitory concentration (MICp) and minimum lethal concentration (MLCp) of the R. mucilaginosa and S. boulardii planktonic cells were determined, as well as minimum biofilm eradication concentration (MBEC). Metal removal efficiency was determined by batch biosorption assay. Previous studies had focused on heavy metal tolerance and removal efficiency of planktonic cells from Rhodotorula species only. Hence, our study presents and compares results for metal tolerance and removal efficiency of the R. mucilaginosa planktonic cells and biofilm. Biofilm tolerance was higher than the planktonic cells. The R. mucilaginosa planktonic cells showed the tolerance in the presence of Hg2+ (MICp 0.08 mM), Cu2+ (MICp 6.40 mM), and Pb2+ (MICp 3.51 mM), while the S. boulardii planktonic cells only tolerated Pb2+ (MICp 0.43 mM). The R. mucilaginosa biofilm showed the highest tolerance in the presence of Hg2+ (MBEC >0.31 mM), Cu2+(MBEC >12.81 mM), Pb2+ (MBEC >7.12 mM), and obtained results were confirmed by fluorescence microscopy. S. boulardii did not show potential in biofilm formation. The R. mucilaginosa biofilm exhibited better efficiency in removal of all tested metals than the planktonic cells. Metal removal efficiency was in the range from 4.79–10.25% for planktonic cells and 91.71–95.39% for biofilm. 相似文献