Lignin microspheres as a nature-based material for effective - PowerPoint Presentation

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Lignin microspheres as a nature-based material for effectivenickel(II) and cadmium(II) ions removal

Tijana Stanišić, Ana Popović, Jelena Rusmirović, Maja Đolić, Mirjana Ristić, Aleksandra Perić-Grujić and Aleksandar Marinković

Environmental pollution caused by fast growing population, urbanization andindustrialization has become a serious threat to the contemporary society

Sustainable development and the circular economy are becoming the new imperative of industrial growth, as the world faces the depletion of natural resources and consequences of climate changeEnvironmental migration of metals depends on a number of chemical processes such as coagulation, adsorption and coprecipitation, desorption, ion exchange, hydroxide and carbonate dissolutionlignin is considered as an environmentally friendly bio-adsorbent for the effective removal of heavy metal ions from wastewater

characteristics of

heavy

metal

ions:high toxicity, Carcinogenicitynon-degradability Persistencehigh solubility and mobility To facilitate the monitoring of pollution there are strictly prescribed and legally enforced regulations indicating the permitted concentrations of hazardous and noxious substances in the environment

Cd0,003 mg/L

Ni0,02 mg/L

Heavy metals

various treatment processes for removing heavy metals from aqueous solutions: Chemical precipitation, ion exchange, adsorption, membrane technology, electrochemical

treatment, coagulation and flocculation Adsorption is commonly used technique for the removal of metal ions from various industrial effluents Adsorption is a process that occurs when a gas or liquid solute accumulates on the surface of a solid or a liquid (adsorbent), forming a molecular or atomic film (the adsorbate)advantages of adsorption: ease of operation, high removal efficiency and the availability of various adsorbents that can be regenerated

Adsorption

Lignin is a natural amorphous polymer that has great potential for use as a building block in the production of bio

renewable materials Lignin is an abundant natural polymer present in lignocellulosic biomass (15-30% by weight), together with cellulose and hemicelluloses it has complex macromolecular three-dimensional structure and presence of methoxyL, phenolic and aliphatic hydroxyl, ketone and aldehyde groups Lignin offers advantages of abundance, lowing cost, good stability, biocompatibility and sufficient oxygen containing functional groups, etc., making it a potential polymer for the retention of heavy metalsThe modifications of wood derivates, such as cellulose and lignin, are widely applied as natural polymers due to their economic feasibility, ecological similarity and adsorption capabilities

Lignin

the lack of raw lignin is a small specific surface area 

chemical modification of the adsorbent, to different functional groupsCompared to traditional adsorbents, microspheres provide a larger surface area and possess better diffusion, dispersion, and mass transfer behaviorThe prepared LMS was with 36.9 m2 g-1 surface area and 7.7 mmol g-1 of terminal amino groups. The

subject of this paper is the adsorption of nickel and cadmium from aqueous solutions using

modified lignin-lignin microspheres with 5.0 mass% alginate

Testing in batch system, 24 samplesInvestigation of the influence of contact time, temperature and mass of the adsorbentThe initial concentration of nickel and cadmium is 10 mg/LThe pH of the nickel solution was 5.5 and the cadmium solution was 6.0

Three different temperatures of 298K, 308K and 318KThe porous microspheres are of a radius of 50 to 950 microns and a surface area of 36.9 m2 g-1 were synthesized via inverse suspension copolymerization of the kraft lignin with a poly(ethylene imine) grafting-agent and an epichlorohydrin cross-linker

E

XPERIMENTAL

S

ECTION

SEM

Structural and surface characteristics

FTIR

The determined pHPZC of A-LMS_5 was 6.2percentage uptake of the

Cd2+ and Ni2+ ions increases with an increase in pH from 4 to 8 In the 6-8 pH range, the maximum uptake (close to 100%) of Ni2+ and Cd2+

ions is observed

T=298, 308 i 318 K; m=1, 5, 7,5 i 10 mg; Co=10 mg/L ; t=60 min

Absorption parameters according to models of absorption isotherms

Metal

T (K)

Lengmirov model

Frojndlihov model

   Cd

2+ qmax( mg/g)Kl(L/m

g

)

R

2

n

K

f

R

2

298

51,3

0,27

0,984

1,972

18,9

0,931

308

96,2

0,21

0,985

1,364

18,4

0,993

318

80,0

0,79

0,9931,38813,30,995

 Metal T (K) Lengmirov model Frojndlihov model   Ni 2+  qmax( mg/g)Kl (L/mg)R2 nKfR2298 62,10,200,8610,1392,90,92730855,90,260,9231,88816,30,98231889,30,500,9901,36014,20,999

Kinetic parameters

T=298, 308 i 318 K

t=5, 15, 30 i 90 min

m=1,0 mg

Co=10 mg/L

MetalT (K)

 Pseudo – prvi red

Pseudo – drugi red   Cd 2+ 

q

e, exp ( mg/g)

q

e1(mg/g)

k

1(L/min)

R

2

q

e2 (mg/g)

k

2(g/mg min)

R

2

298

42,254

14,911

0,038

0,826

44,250

0,005

0,998

308

43,254

10,723

0,028

0,85143,4780,0091,00031852,25329,7850,041

0,98154,9450,0030,996MetalT (K) Pseudo – prvi redPseudo – drugi red  Ni2+  qe, exp ( mg/g)qe1( mg/g)k1(L/min)R2qe2( mg/g)k2(g/mg min)R229845,962 13,5930,0360,98540,9840,0090,99930841,84516,0320,0360,88643,4780,0051,000318

40,325

18,993

0,025

0,932

40,9840,0040,999

The process is spontaneous and endothermic

Thermodynamic parameters

Metal

T (K)

K

l (L/mol)∆G0

(kJ/mol)∆H0 (kJ/mol)∆S0

(kJ/K mol) Cd2+

29830010,8-25,542

42,211

0,225

308

23941,2

-25,821

318

89133,2

-30,134

Metal

T (K)

K

l

(L/mol)

∆G

0

(kJ/mol)

∆H

0

(kJ/mol)

∆S

0

(kJ/K mol)

Ni

2+

29811972,7-23,265 35,231 0,196

30815142,0-24,64731829427,2-27,204

adsorption process has great potential for the elimination of heavy metals from Industrial wastewater using low cost adsorbents lignin is still

continuously researched for reaching its full potential as an eco-friendly bio-adsorbent for efficient removal of heavy-metal ions from Chemical modification of adsorbents with certain functional groups has proven to be an effective way to improve their adsorption propertiesThe maximum adsorption capacity of the A-LMS for nickel (II) ions was 89.286 mg g-1 at a temperatureof 318 K, while for the adsorption of cadmium(II) ions it was 96.154 mg g-1 at a temperature of308 K. Based on the obtained, presented and analyzed results of the adsorption process, it can be concluded that the modified lignin can be used as an effective adsorbent for the removal of nickel and cadmium ions from aqueous solutions

Conclusion