Adsorption, concentration, and recovery of aqueous heavy metal ions with the root powder

Adsorption, concentration, and recovery of aqueous heavy metal ions with the root powder
Adsorption, concentration, and recovery of aqueous heavy metal ions with the root powder

Ecological Engineering 60 (2013) 160–166

Contents lists available at ScienceDirect

Ecological

Engineering

j o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /e c o l e n

g

Adsorption,concentration,and recovery of aqueous heavy metal ions with the root powder of Eichhornia crassipes

Xiaosen Li a ,Songlin Liu a ,Zhongyuan Na b ,Diannan Lu a ,Zheng Liu a ,?

a Department of Chemical Engineering,Tsinghua University,Beijing 100084,China b

Institute of Ecological Agriculture,Yunnan 650000,China

a r t i c l e

i n f o

Article history:

Received 5January 2013

Received in revised form 27June 2013Accepted 6July 2013

Available online 14 August 2013

Keywords:

Eichhornia crassipes Heavy metal uptake

Adsorption/desorption mechanism

a b s t r a c t

We investigated the adsorption of aqueous Cu 2+and Cr 3+,as model heavy metal ions,by the root powder of Eichhornia crassipes ,followed by combustion to establish an economical route suitable for large-scale recovery of heavy metal ions from wastewater.In the optimal pH range of 5.0–6.0,the adsorption reached equilibrium after 30min and could be described by Langmuir isotherms with maximum adsorption capac-ities of 32.51mg/g for Cu 2+and 33.98mg/g for Cr 3+.A pseudo-second-order kinetic model was applied to describe the adsorption kinetics.We concluded from Fourier transform infrared spectroscopy that functional groups containing OH and COOH contributed to the adsorption.During adsorption,Ca 2+,Mg 2+,and K +were discharged from the root powder.Electrostatic interactions also played an important role in the absorption process.X-ray photoelectron spectroscopy analysis suggested that this long-root adsorbent appeared to chelate Cr 3+more strongly than Cu 2+,both of which appeared on the surface and in the interior of the adsorbent;both were eluted best with H 2SO https://www.360docs.net/doc/5416115350.html,busting the saturated adsorbent generated a product with high concentrations of metal ions:23%w/w Cu 2+and 30%w/w Cr 3+,values equal or higher than the regular contents of mine ore (20–25%w/w).Thus,this process created a product that was favorable for subsequent processing.

? 2013 Elsevier B.V. All rights reserved.

1.Introduction

Recovering heavy metal ions from industrial or urban ef?uents,particularly those toxic to human beings,animals,and plants,is an important issue for both environmental safety and resource sustainability.A number of methods to remove heavy metal ions,such as precipitation,coagulation,solvent extraction,electroly-sis,membrane separation,ion exchange,and adsorption (Bai and Abraham,2003;Bailey et al.,1999;Ucun et al.,2002)have been developed and tested.These methods are not ef?cient for treat-ing dilute solutions,and recovering valuable heavy metals is an important but unful?lled objective.Increasing efforts have been made in recent years to ?nd biodegradable adsorbents,such as plants (Dhir and Srivastava,2011;Zuo et al.,2012),fungi (Bingol et al.,2004),lignin (Sciban et al.,2011),alginate (Singh et al.,2012),algae (Areco et al.,2012;Aravindhan et al.,2004;Bulgariu and Bulgariu,2012;Cabatingan et al.,2001;Lee and Chang,2011),and other biomaterials (Sharma and Bhattacharyya,2005;Schneegurt et al.,2001)that can recover metal ions.These biodegradable adsor-bents are advantageous over chemically synthesized adsorbents

?Corresponding author.Tel.:+861062779876.

E-mail address:liuzheng@https://www.360docs.net/doc/5416115350.html, (Z.Liu).

because a saturated biodegradable adsorbent can be combusted to remove the majority of the adsorbent,concentrating the heavy metal species into a feedstock for subsequent processing.Because of this advantage,the adsorption/desorption mechanism and the microstructure of these adsorbents should be investigated more thoroughly.

Long-root Eichhornia crassipes ,termed because of its morpho-logical characteristics,is being tested for the on-site treatment of Dianchi Lake in China because of its extraordinary uptake of aqueous nitrogen and phosphorus and its ability to adsorb other hazardous compounds such as arsenic contaminants (Lin et al.,2012).It is also expected that recovery and concentration of the adsorbed metal ions from the saturated plant adsorbent can be done conveniently.This method could provide an ecologically friendly way to deal with eutrophic wastewater while recover-ing valuable heavy metals.Thus,this study aims to examine the adsorption behavior toward heavy metal ions,the mechanism of adsorption,and the adsorbent microstructure of long-root E.cras-sipes and subsequent recovery of the metal ions by combustion.In this work,we prepared the root powder of long-root E.cras-sipes as the adsorbent,and we chose Cu 2+and Cr 3+as representative heavy metal ions.We began the experimental study by examining the adsorption of Cu 2+and Cr 3+as a function of pH and salt concen-tration,followed by a study of adsorption kinetics and isotherms.

0925-8574/$–see front matter ? 2013 Elsevier B.V. All rights reserved.https://www.360docs.net/doc/5416115350.html,/10.1016/j.ecoleng.2013.07.039

X.Li et al./Ecological Engineering60 (2013) 160–166161 Fourier transform infrared spectroscopy(FTIR)and X-ray photo-

electron spectroscopy(XPS)were used to explore the interactions

between the metal ions and the adsorbent.The adsorption of Cu2+

and Cr3+was accompanied by the discharge of Ca2+,Mg2+,and

K+from the adsorbent,indicating an ion-exchange mechanism.A

scanning electron microscopy(SEM)with a back-scattered elec-

tron detector(BSE)was used to determine the adsorption sites.We

combusted the root powder of long-root E.crassipes saturated with

adsorbed metal ions to con?rm the effectiveness of the process in

removing biomass while concentrating metal ions.

2.Materials and methods

2.1.Materials

The chemical reagents used in this work were of analytically

pure grade.The heavy metal solutions were prepared by dissolving

appropriate amounts of CuCl2·2H2O and CrCl3·6H2O in deionized

water.NaOH and HCl solutions were used to adjust the pH of

the heavy metal solutions.Standard metal solutions with con-

centrations of1000mg/L purchased from the National Institute of

Metrology(Beijing,China)were used to calibrate our?ame atomic

absorption spectroscope.All glassware was soaked in10%HCl and

washed with deionized water at least three times before use.The

particle size of the adsorbent prepared from the root powder of

long-root E.crassipes was300–600?m in diameter.The elemental

contents of C,H,O,and N were47.23%,4.72%,44.4%,and1.98%,

respectively.

2.2.Adsorption experiment

One gram of the adsorbent was added to a100mL aliquot

containing the Cu2+or Cr3+solution at an appropriate pH and

concentration in a300mL?ask.The initial concentration of the

metal was100mg/L.The?ask was then placed in a BOD incuba-

tor shaker(Sky-111B,SuKun,China)at30?C with a rotation speed

of175rpm.The supernatants were sampled at given time inter-

vals.After?ltering through a0.45?m membrane,we determined

the concentrations of Cu2+and Cr3+using?ame atomic absorption

spectroscopy(FAAS;Z-5000,Hitachi,Japan).The wavelengths of

heavy metal were324.8nm for Cu2+and357.9nm for Cr3+with

operational currents of5.0mA and7.5mA,respectively.We inter-

preted the extent of adsorption according to the initial and?nal

concentrations of the solution.The removal ratio(R)was then cal-

culated using Eq.(1).

R=C i?C eq

C i

×100%(1)

Where C i and C eq are the initial and equilibrium concentrations of the solution,respectively.We performed adsorptions of Cu2+and Cr3+ions at different pH values from1.0to7.0.We studied the effect of salt on the adsorption behavior at a pH of5.0with a NaCl concentration of0–300mmol/L.Each experiment was carried out in triplicate with deviation less than5%.

2.3.Desorption experiment

The desorption of metal ions was carried out using100mL of elution buffer containing0.2M HCl,0.2M HNO3,0.2M H2SO4, 0.2M thiourea,0.2M HCl,and0.2M EDTA.During each run,the above solution was mixed with the adsorbent saturated with metal ions in a300mL?ask.The?ask was then placed in the BOD incu-bator shaker at30?C with a rotation speed of175rpm for2h.The solutions were?ltered through a0.45?m membrane and the con-centrations of metal ions were measured by FAAS as

mentioned

Fig.1.FTIR spectra of the root powders before and after adsorption. above,based on which the recovery yield was obtained.Each exper-iment was triplicate with deviation less than5%.

2.4.Assays

We used FTIR(Nicoletis10,Thermo Scienti?c,USA),XPS(PHI-5300,Perkin-Elmer,USA),and SEM-BSE(JSM-6460LV Japan)to identify the major functional groups of the adsorbent and the sites responsible for the adsorption.We?rst added the root-powder adsorbents to the300mg/L metal solutions at a pH of5.0.After the samples reached absorption equilibrium,they were analyzed by FTIR,XPS,and SEM-BSE.

The concentrations of Ca2+,Mg2+,and K+in solution were mea-sured by FAAS before and after adsorption;one adsorbent washed with deionized water served as the control.For these experiments, 1g of root powder was added into100mL of the metal solution (500mg/L)at a pH of5.0.The pH value of the solution was deter-mined using a pH meter(SevenEasy,Mettler,Switzerland).The net release of cations(mM/g of absorbent)was con?rmed using a solu-tion without metal ions as the control.After combustion,we used X-ray diffraction(XRD;D8-Advance,Bruker,Germany)and X-ray ?uorescence(XRF;XRF-1800,Shimadzu,Japan)to determine the compositions of the residual materials.

3.Results and discussion

3.1.Characterization of the adsorption of Cu2+and Cr3+

FTIR and XPS,which have been extensively used to character-ize adsorption of metal compounds(Altenor et al.,2009;Hartono et al.,2009;Wang et al.,2013),were used in this study to study the adsorbent.As shown in Fig.1and Table1,after adsorption the OH peak shifted from3412cm?1to around3350cm?1.This shift could be caused by the formation of a complex between metal ions and the OH groups of the adsorbent.The peak at1321cm?1

Table1

List of peak shifts.

Peak Associated

functional

group

Shift

Before adsorption After adsorption

34123350OH62±8 1321disappeared COOH–

162X.Li et al./Ecological Engineering60 (2013) 160–

166

Fig.2.Binding energies of the1s electrons of O on the powder. disappeared after adsorption,indicating that the carboxyl group also contributed to the formation of a complex with Cu2+and Cr3+.

Fig.2shows how the binding energies of the1s electrons of O on the surface of the powder change after adsorption.The elec-tron binding energy of O1s decreased by an average of0.370eV after adsorption of Cu2+and decreased by0.643eV after adsorp-tion of Cr3+.These results indicate that stronger chelation occurs between Cr3+and the adsorbent than between Cu2+and the adsor-bent,which leads to a different desorption ef?ciency for the two ions(see Section3.7).

The Ca2+,Mg2+,and K+contents of the root powder were determined by XRF.The variation of these ions before and after adsorption was determined by FAAS.These results are shown in Table2,in which the net discharge of these ions after washing with deionized water was measured as the control.As Table2shows, Ca2+,Mg2+,and K+were discharged from the root powder while Cu2+and Cr3+were adsorbed.This behavior suggests that Cu2+and Cr3+displaced Ca2+,Mg2+,and K+from the adsorbent.

3.2.Distribution of adsorption sites

SEM-BSE was used to monitor the heavy metal ions being adsorbed.The results are shown in Fig.3(a)–(c).

Figs.3(a)–(c)show the existence of adsorbed metal ions in the white areas.Adsorbed Cu2+and Cr3+appeared both inside and out-side the porous adsorbent.This behavior suggests that the Cu2+and Cr3+ions were not exclusively adsorbed on either the inner or outer surface of the plant cell wall,which was also observed by Conrad (2008).

3.3.Effect of pH on adsorption

We carried out these experiments at a pH of1.0–7.0in order to identify the optimal pH.The initial concentration of Cu2+or Cr3+ was100mg/L.As shown in Fig.4,increasing the pH signi?cantly increased the adsorption capacity for both Cu2+and Cr3+.Similar

Table2

Discharge of Ca2+,Mg2+,and K+during adsorption.

Loading of Cu2+and

Cr3+(mM/g)

Net release(mM/g)

Mg2+Ca2+K+

Cu2+0.4110.3330.0250.042 Cr3+0.5070.3270.051

0.106Fig.3.SEM(backscattering)images of adsorbents without adsorbed heavy metal ions and those saturated with Cu2+and Cr3+.

X.Li et al./Ecological Engineering 60 (2013) 160–166

163

Table 3

Regression parameters for adsorption of Cu 2+and Cr 3+.

Kinetic models

Q e ±s (mg/g)

R 2±s

Cu 2+

Cr 3+

Cu 2+

Cr 3+

Pseudo-second-order model 13.15±0.2613.00±0.090.99440.9994Pseudo-?rst-order model

13.00±0.16

13.08±0.26

0.9836

0.8589

adsorption behaviors have also been identi?ed in other biomass adsorbents such as algae,apple waste,and pine bark (Chen and Yiacoumi,1997;Crist et al.,1992,1994;Kratochvil et al.,1995;Lee and Yang,1997;Seco et al.,1997;Yu and Kaewsarn,1999).This pH dependence of adsorption capacity may be caused by the increased availability of OH and COOH,which chelate with the metal ions.We carried out the adsorption at a pH of 5.0;thus,hydrolysis of the metal ions is not signi?cant and has little effect on our results (Villaescusa et al.,2004).

3.4.Characterization of the adsorption kinetics at the optimal pH

Fig.5shows the adsorption of Cu 2+and Cr 3+over time at the optimal pH of 5.After 20min,an adsorption degree of 80%was achieved.Other agricultural by-products used to absorb Cu 2+and Cd 2+have been found to have similar adsorption

kinetics

Fig.4.Adsorption of Cu 2+and Cr 3+at different pH

values.

Fig.5.Adsorption over time of Cu

2+

and Cr 3+

.Initial metal concentration is 100mg/L.

(Kratochvil et al.,1995;Lee and Yang,1997).This rapid adsorption of metals allows for greater economy and ef?ciency.

We applied pseudo-?rst-order and pseudo-second-order kinetic models (Chen and Wang,2007;Ho et al.,1996;Unnithan and Anirudhan,2001)to simulate the above-mentioned adsorp-tion process.These two kinetic models can be described as follows:

Q t =Q e

1?

1

exp (V 0t )

(2)

t Q t =1V 0Q 2e

+t Q e (3)

where Q e is the equilibrium adsorption capacity in solution,Q t is the adsorption amount at time t ,and V 0is the initial adsorption rate.

The regression parameters of these two kinetic models are listed in Table 3.The R 2values for the pseudo-?rst-order kinetic model are 0.9836and 0.8588for Cu 2+and Cr 3+,respectively;the R 2values for the pseudo-second-order kinetic model are 0.9944and 0.9994,respectively.The better ?t by the pseudo-second-order kinetic model may be underpinned by the presence of two mechanisms in the adsorption process:chemical sorption (rapid)and subsequent slow ion exchange (slow)(Villaescusa et al.,2004),supported by the observed release of Ca 2+,Mg 2+,and K +.

3.5.Adsorption isotherms at the optimal pH

We performed regression analysis using Langmuir and Freund-lich isotherms on the data of Cu 2+and Cr 3+adsorption at pH 5.0,described by the following equations,

Q e =

Q max bC e 1+bC e

(4)

ln Q e =

1n

ln C e +ln K F

(5)

where Q e and Q max are the equilibrium and saturated adsorp-tion capacities of the adsorbent,respectively.C e is the equilibrium concentration of the metals in the solution and b is the adsorp-tion constant.K F and n are the empirical constant for Freundlich isotherm.

As shown in Fig.6and Table 4,the Langmuir model offers a bet-ter description of the adsorption behavior than does the Freundlich model.Additionally,the Q max of Cr 3+is greater than that of Cu 2+.The better agreement of the Langmuir model indicates that “mono-layer coverage”occurs on the surface of the root powder by the two metals.As Table 4shows,the Q max values of both Cu 2+and Cr 3+are above 30mg/g of absorbent,much higher than those of other reported biodegradable adsorbents such as pine bark (Al-Asheh and Duvnjak,1998)and grape stalks (Villaescusa et al.,2004).

3.6.Effect of salt concentration on adsorption

In practice,industrial wastewater and urban ef?uents contain various salts that may affect adsorption.To examine how salt con-centration affects adsorption of the heavy metal ions explored in

164X.Li et al./Ecological Engineering 60 (2013) 160–166

Table 4

Comparison of Langmuir and Freundlich models for adsorption.

Metal ions

R 2

Q max (mg/g)

Langmuir model

Freundlich model

Langmuir model

Freundlich model

Cu 2+0.97880.943132.5134.82Cr 3+0.9819

0.9442

33.98

36.14

Table 5

Metal ions present after combustion determined by XRF.

Bare adsorbent

Cu 2+saturated adsorbent

Cr 3+saturated adsorbent

Element

Content (%)

Element

Content (%)

Element

Content (%)

K 15.90K 2.66K 2.50Si 14.46Si 26.63Si 25.55Fe 13.98Fe 16.13Fe 22.34Mg 11.05Al 12.07Al 14.50Cu 0.04Cu 30.70Cu 0.06Cr

0.11

Cr

0.05

Cr

23.41

Elements with contents below 10%are not listed.

this paper,we added sodium chloride to the solution.The con-centration of NaCl was 0–300mM.The initial concentration of the metal was 100mg/L and the pH was 5.0.

As Fig.7shows,increasing the NaCl concentration decreases the adsorption capacity for the heavy metal ions,particularly Cr 3+.This behavior suggests that electrostatic interactions between the metal ions and the adsorbent dominate the absorption process and that copper and chromium are adsorbed through

different

Fig.6.Adsorption isotherm.

mechanisms (Flogeac et al.,2004,2003).This same effect was also observed when cork waste was used as an adsorbent of metals ions (Villaescusa et al.,2000).It is known that the presence of salt formed by strong acid and alkali increases the ionic strength of the solution.This increase in ionic strength depresses the adsorption based on electrostatic interactions,and thus reduces the adsorp-tion capacities of Cu 2+and Cr 3+,as shown in Fig.7.The

disparate

Fig.7.Adsorption of Cu 2+and Cr 3+metal ions as a function of NaCl

concentration.

Fig.8.Desorption of Cu 2+and Cr 3+.

X.Li et al./Ecological Engineering60 (2013) 160–166

165

Fig.9.XRD analysis of adsorbents after combustion.

change of the adsorption capacities of Cu2+and Cr3+may be rooted in their difference in outer layer electron distributions,leading to different af?nities toward the COO?group(Villaescusa et al., 2004).3.7.Desorption of metal ions from the adsorbent

We performed batch desorption using elution buffer with0.2M HCl,0.2M H2SO4,0.2M HNO3,0.2M thiourea,0.2M HCl,and0.2M EDTA.These results are shown in Fig.8.The elution of Cu2+was more complete than that of Cr3+.XPS shows a stronger interac-tion of Cr3+with the adsorbent compared to that of Cu2+with the adsorbent.Additionally,because of the Jahn-Teller effect,the coor-dination compound formed by Cu2+and the root powder is weaker than that formed by Cr3+and the root powder,leading to easy elu-tion of Cu2+(Parkman et al.,1999).When we compared the elution solutions,we found that using H2SO4gives the best recovery of both Cu2+(>90%)and Cr3+(>50%).

https://www.360docs.net/doc/5416115350.html,bustion of adsorbents saturated with metal ions

During this experiment,we added1g of the adsorbent to100mL aliquots of Cu2+or Cr3+solutions,each with a pH of5.0and a 300mg/L initial concentration of the metal(Cu2+or Cr3+).After adsorption,the metal contents of the loaded root powder are 30.3mg/g for Cu2+and28.8mg/g for Cr3+.We then combusted the adsorbent as the?rst step of recovering the metal ions.We used a muf?e furnace at700?C for2h,which decomposed the long-root powder adsorbent.We then used XRD and XRF to determine the composition of the residual material.The results are shown in Fig.9(a)–(c).

Fig.9shows that K present in the bare adsorbent(Fig.9(a))dis-appears in the adsorbents saturated with Cu2+or Cr3+,as shown in Fig.9(b)and(c),respectively.We attribute this disappearance to replacement by Cu2+and Cr3+,as shown in Table1.

We used XRF to determine the contents of ions in the adsorbents after combustion,which are shown in Table5.

Combusting the adsorbents induced weight loss:90.2%for the Cu2+-saturated adsorbent and87.1%for the Cr3+-saturated adsor-bent.The?nal contents of Cu2+and Cr3+are30.70%w/w and23.41% w/w,respectively.These values are equal or greater than the reg-ular content of mine ore,around20–25%w/w(Chrysochoou and Dermatas,2006;Gu et al.,2005).Combustion’s ease of operation, effective removal of biomass,and high concentration of metal ions in the resultant concentrate make it a suitable choice for treating long-root E.Crassipes saturated with metal ions.Similar adsorp-tion and concentration behavior has been identi?ed in other kinds of biomass adsorbents such as Pteris vittata and E.acicularis(Kalve et al.,2011;Sakakibara et al.,2011).

4.Conclusion

We validated the adsorption of Cu2+and Cr3+as representa-tive heavy metal ions in wastewater by the powder of long-root E.crassipes.We attributed this adsorption to the formation of com-plexes with the hydroxyl and carboxyl groups,supported by FTIR analysis.XPS analysis revealed that the adsorbent more strongly chelated to Cr3+than to Cu2+.SEM-BSE showed adsorption sites distributed across both the inside and outside of the structure. Adsorption was accompanied by release of Ca2+,Mg2+,and K+, indicating an ion-exchange displacement mechanism.The adsorp-tion could be described by the Langmuir isotherm.Optimizing the pH to5–6gave maximum adsorption capacities of32.5mg/g and 34.0mg/g for Cu2+and Cr3+,respectively.The adsorbent reached equilibrium within30min and could be described by a pseudo-second-order kinetic https://www.360docs.net/doc/5416115350.html,busting the saturated adsorbent at700?C removed most of the biomass and generated a prod-uct with higher concentrations of the metal ions;thus,it was favorable for subsequent re?ning.Our results provide an effective way to treat wastewater contaminated by metal ions.

166X.Li et al./Ecological Engineering60 (2013) 160–166

References

Areco,M.M.,Hanela,S.,Duran,J.,Afonso,M.D.,2012.Biosorption of Cu(II),Zn(II), Cd(II)and Pb(II)by dead biomasses of green alga Ulvalactuca and the develop-ment of a sustainable matrix for adsorption implementation.J.Hazard.Mater.

213,123–132.

Altenor,S.,Carene,B.,Emmanuel,E.,Lambert,J.,Ehrhardt,J.,Gaspard,S.,2009.

Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation.J.Hazard.Mater.15,1029–1039. Aravindhan,R.,Madhan,B.,Rao,J.R.,Nair,B.U.,Ramasami,T.,2004.Bioaccumulation of chromium from tannery wastewater:an approach for chrome recovery and reuse.Environ.Sci.Technol.38,300–306.

Al-Asheh,S.,Duvnjak,Z.,1998.Binary metal sorption by Pine Bark:study of equi-libriaand mechanisms.Sep.Sci.Technol.9,1303–1329.

Bulgariu,D.,Bulgariu,L.,2012.Equilibrium and kinetics studies of heavy metal ions biosorption on green algae waste biomass.Bioresour.Technol.103,489–493. Bingol,A.,Ucun,H.,Bayhan,Y.K.,Karagunduz,A.,Cakici,A.,Keskinler,B.,2004.

Removal of chromate anions from aqueous stream by a cationic surfactant-modi?ed yeast.Bioresour.Technol.94,245–249.

Bai,R.S.,Abraham,T.E.,2003.Studies on chromium(VI)adsorption–desorption using immobilized fungal biomass.Bioresour.Technol.87,17–26.

Bailey,S.E.,Olin,T.J.,Bricka,R.M.,Adrian,D.D.,1999.A review of potentially low-cost sorbents for heavy metals.Water Res.33,2469–2479.

Conrad,K.,2008.Correlation between the distribution of lignin and pectinand distri-bution of sorbed metal ions(lead and zinc)on coir(Cocosnucifera L.).Bioresour.

Technol.99,8476–8484.

Chen,H.,Wang,A.Q.,2007.Kinetic and isothermal studies of lead ion adsorption onto Palygorskite clay.Colloid Interf.Sci.307,309–316.

Chrysochoou,M.,Dermatas,D.,2006.Application of the Rietveld method to assess chromium(VI)speciation in chromite ore processing residue.J.Hazard.Mater.

5,370–377.

Cabatingan,L.K.,Agapay,R.C.,Rakels,J.L.L.,Ottens,M.,van der Wielen,L.A.M.,2001.

Potential of biosorption for the recovery of chromate in industrial wastewaters.

Ind.Eng.Chem.Res.40,2302–2309.

Chen,J.P.,Yiacoumi,S.,1997.Biosorption of metal ions from aqueous solution.Sep.

Sci.Technol.32,51–69.

Crist,R.H.,Oberholser,K.,McGarrity,J.,Crist,D.R.,Johnson,J.K.,Brittsan,J.M.,1992.

Interaction of metals and protons with algae.3.marine-algae,with emphasis on lead and aluminum.Environ.Sci.Technol.26,496–502.

Crist,R.H.,Martin,J.R.,Carr,D.,Watson,J.R.,Clarke,H.J.,Crist,D.R.,1994.Interaction of metals and protons with algae.4.ion-exchange VS adsorption models and a reassessment of scatchard plots-ion-exchange rates and equilibria compared with calcium alginate.Environ.Sci.Technol.28,1859–1866.

Dhir,B.,Srivastava,S.,2011.Heavy metal removal from a multi-metal solution and wastewater by Salvinianatans.Ecol.Eng.37,893–896.

Flogeac,K.,Guillon,E.,Aplincourt,M.,2004.Surface Complexation of Copper(II)on Soil Particles:EPR and XAFS Studies.Environ.Sci.Technol.38,3098–3103. Flogeac,K.,Guillon,E.,Marceau,E.,Aplincourt,M.,2003.Speciation of chromium on a straw lignin:adsorption isotherm,EPR,and XAS studies.New J.Chem.27, 714–720.

Gu,L.X.,Zheng,Y.C.,Tang,X.Q.,2005.Copper,gold and silver enrichment in ore mylonites within massive sulphideorebodies at HongtoushanVHMS deposit, N.E.China.Ore.Geol.Rev.9,1–29.

Hartono,S.B.,Qiao,S.Z.,Jack,K.,Ladewig,B.P.,Hao,Z.P.,Lu,G.Q.,2009.Improv-ing adsorbent properties of cage-like ordered amine functionalized mesoporous silica with very large pores for https://www.360docs.net/doc/5416115350.html,ngmuir.25,6413–6424.Ho,Y.S.,Wase,D.A.J.,Forster,C.F.,1996.Kinetic studies of competitive heavy metal adsorption by sphagnum moss peat.Environ.Technol.17,71–77.

Kalve,S.,Sarangi,B.K.,Pandey,R.A.,Chakrabarti,T.,2011.Arsenic and chromiumhy-peraccumulation by an ecotype of Pterisvittata-prospective for phyto extraction from contaminated water and soil.Curr.Sci.100,888–894.

Kratochvil,D.,Fourest,E.,Volesky,B.,1995.Biosorption of copper by Sargassum ?uitans biomass in?xed-bed column.Biotechnol.Lett.17,777–782.

Lin,S.,Wang,G.X.,Na,Z.Y.,Lu,D.N.,Liu,Z.,2012.Long-root Eichhornia crassipes as a biodegradable adsorbent for aqueous As(III)and As(V).Chem.Eng.J.183, 365–371.

Lee,Y.C.,Chang,S.P.,2011.The biosorption of heavy metals from aqueous solution by Spirogyra and Cladophora?lamentous macroalgae.Bioresour.Technol.102, 5297–5304.

Lee,S.H.,Yang,J.W.,1997.Removal of copper in aqueous solution by apple wastes.

Sep.Sci.Technol.32,1371–1387.

Parkman,R.H.,Charnock,J.M.,Bryan,N.D.,Livens,F.R.,Vaughan,D.J.,1999.Reactions of copper and cadmium ions in aqueous solution with goethite,lepidocrocite, mackinawite,and pyrite.Am.Mineral.84,407–419.

Sakakibara,M.,Ohmori,Y.,Ha,N.T.H.,Sano,S.,Sera,K.,2011.Phytoremediation of heavy metal contaminated water and sediment by Eleocharisacicularis.Clean: Soil Air Water39,735–741.

Singh,L.,Pavankumar,A.R.,Lakshmanan,R.,Rajarao,G.K.,2012.Effective removal of Cu2+ions from aqueous medium using alginate as biosorbent.Ecol.Eng.38, 119–124.

Sciban,M.B.,Klasnja,M.T.,Antov,M.G.,2011.Study of the biosorption of different heavy metal ions onto Kraft lignin.Ecol.Eng.37,2092–2095.

Schneegurt,M.A.,Jain,J.C.,Menicucci,J.A.,Brown,S.A.,Kemner,K.M.,Garofalo,D.F., Quallick,M.R.,Neal,C.R.,Kulpa,C.F.,2001.Biomass byproducts for the remedi-ation of wastewaters contaminated with toxic metals.Environ.Sci.Technol.35, 3786–3791.

Sharma,A.,Bhattacharyya,K.G.,2005.Azadirachtaindica(Neem)leaf powder as a biosorbent for removal of Cd(II)from aqueous medium.J.Hazard.Mater.125 (2005),102–112.

Seco,A.,Marzal,P.,Gabaldon,C.,1997.Adsorption of heavy metals from aqueous solutions onto activated carbon in single Cu and Ni Systems and in binary Cu–Ni, Cu–Cd and Cu–Zn systems.J.Chem.Technol.Biotechnol.70,23–30.

Ucun,H.,Bayhan,Y.K.,Kaya,Y.,Cakici, A.,Algur,O.F.,2002.Biosorption of chromium(VI)from aqueous solution by cone biomass of Pinussylvestris.Biore-sour.Technol.85,155–158.

Unnithan,M.R.,Anirudhan,T.S.,2001.The kinetics and thermodynamics of sorption of chromium(VI)onto the iron(III)complex of a carboxylated polyacrylamide-grafted sawdust.Ind.Eng.Chem.40,2693–2701.

Villaescusa,I.,Fiol,N.,Mart?nez,M.,2004.Removal of copper and nickel ions from aqueoussolutions by grape stalks wastes.Water Res.38,992–1002. Villaescusa,I.,Mart?nez,M.,Miralles,N.,2000.Heavy metal uptake from aque-ous solution by cork and yohimbe bark wastes.Chem.Technol.Biotechnol.75, 812–816.

Wang,J.,Peng,S.C.,Wan,Z.Q.,Yue,Z.B.,Wu,J.,Chen,T.H.,2013.Feasibility of anaer-obic digested corn stover as biosorbent for heavymetal.Bioresour.Technol.132, 453–456.

Yu,Q.M.,Kaewsarn,P.,1999.Binary adsorption of copper(II)and cadmium(II) from aqueous solutions by biomass of marine alga Durvillaeapotatorum.Sep.

Sci.Technol.34,1595–1605.

Zuo,X.J.,Balasubramanian,R.,Fu,D.F.,Li,H.,2012.Biosorption of copper,zinc and cadmium using sodium hydroxide immersed Cymbopogon schoenanthus L, Spreng(lemon grass).Ecol.Eng.49,186–189.

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员会),负责对脐带血造血干细胞库设置的申请、验收和考评提出论证意见。专家委员会负责制订脐带血 造血干细胞库建设、操作、运行等技术标准。 第八条脐带血造血干细胞库设置的申请者除符合国家规划和布局要求,具备设置一般血站基本条件之外, 还需具备下列条件: (一)具有基本的血液学研究基础和造血干细胞研究能力; (二)具有符合储存不低于1 万份脐带血的高清洁度的空间和冷冻设备的设计规划; (三)具有血细胞生物学、HLA 配型、相关病原体检测、遗传学和冷冻生物学、专供脐带血处理等符合GMP、 GLP 标准的实验室、资料保存室; (四)具有流式细胞仪、程控冷冻仪、PCR 仪和细胞冷冻及相关检测及计算机网络管理等仪器设备; (五)具有独立开展实验血液学、免疫学、造血细胞培养、检测、HLA 配型、病原体检测、冷冻生物学、 管理、质量控制和监测、仪器操作、资料保管和共享等方面的技术、管理和服务人员; (六)具有安全可靠的脐带血来源保证; (七)具备多渠道筹集建设资金运转经费的能力。 第九条设置脐带血造血干细胞库应向所在地省级卫生行政部门提交设置可行性研究报告,内容包括:

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