Porous Materials Obtained from Nonconventional Sources ... · Porous Materials Obtained from...

Porous Materials Obtained fromNonconventional Sources Used inWastewater Treatment Processes

E Coutino-Gonzalez, I Robles-Gutiérrez, M Solís-López, andF Espejel-Ayala

ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Synthesis of Zeolites Using Nonconventional Precursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Synthesis of Zeolites Using Fly Ashes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Synthesis of Zeolites Using Kaolinite and Different Industrial Waste . . . . . . . . . . . . . . . . . . . . . . . 6

Fabrication of Biosorbent Materials and Activated Carbon from Agroindustrial Waste . . . . . . . 9Usage of Zeolites and Activated Carbon Obtained from NonconventionalSources in Wastewater Treatment Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Conclusions and Future Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

AbstractThe acute problem of (agro)industrial waste generation is reaching alarmingvalues. Most of this waste is not properly treated and often disposed in landfillswhere they contribute to the environmental pollution due to the production ofharmful leachates. However, novel synthetic approaches are being nowadaysexplored to produce functional porous materials starting from (agro)industrialwaste, also called nonconventional sources, to fabricate eco-materials that can be

E. Coutino-GonzalezCONACYT – Centro de Investigación y Desarrollo Tecnológico en Electroquímica, Querétaro,Méxicoe-mail: [email protected]

I. Robles-Gutiérrez · F. Espejel-Ayala (*)Centro de Investigación y Desarrollo Tecnológico en Electroquímica, Querétaro, Méxicoe-mail: [email protected]; [email protected]

M. Solís-LópezPrograma de Nanociencias y Nanotecnología, Centro de Investigación y de Estudios Avanzados delInstituto Politécnico Nacional (CINVESTAV-IPN), Ciudad de México, Méxicoe-mail: [email protected]

# Springer International Publishing AG 2018L.M.T. Martínez et al. (eds.), Handbook of Ecomaterials,https://doi.org/10.1007/978-3-319-48281-1_135-1

1

mailto:[email protected]




https://doi.org/10.1007/978-3-319-48281-1_135-1

utilized in decontamination processes imparting to such materials and added(ecologic and economic) value. Recent advances in the production of zeolitesusing industrial waste streams as precursors and biosorbent materials generatedfrom agroindustrial waste will be addressed in this chapter, as well as theirpotential use in wastewater treatment.

Introduction

The initial development of the eco-materials approach was triggered by the concernon the large pollution caused by emerging contaminants in the early 1990s.This concept includes the production of less hazardous materials based on theirgreen environmental profiles to reduce the environmental burden and decrease theamount of residues generated by conventional processes [1, 2]. According to Haladaand Yamamoto [3], eco-materials are defined as those materials that enhance theenvironmental improvement throughout the whole life cycle while maintainingaccountable performance. Such concept play a crucial role in materials science andtechnology in order to minimize environmental impacts, enhance the recyclability ofmaterials, and increase energy and materials efficiency. From the point of view ofmaterial science and engineering, an eco-material should possess at least one amongten superior properties compared to conventional materials [4]. As a result, there is awide range of eco-materials developed in various industries such as iron and steel,electronics, chemicals, paper, construction, textile, and polymers. Additionally theeco-materials concept has continued growing and expanding the principle to otherfields, such as in the area of functional materials fabricated from residues thatpossess the ability to remove pollutants released into the environment [5], giving anew perspective to the reuse and recyclability concepts. Representative emergingmaterials are zeolites synthesized from industrial waste streams and biosorbentmaterials obtained from agroindustrial residues.

The main approach used in the synthesis of zeolites is based on hydrothermalprocesses using inorganic precursors such as sodium silicate and aluminate. Theseform the building blocks that later aggregate into crystalline materials through acrystallization step yielding the final zeolite topology. Several industrial wastesources possess high aluminum and silicon contents and are potential candidatesas precursors for the synthesis of zeolites. The most often utilized are fly ashes,sludge from wastewater plants, and glass and ceramic residues [6–8]. By usingthese precursors, the synthesis of zeolite A, P, X, Y, ZSM-5 and sodalite has beensuccessfully achieved (Fig. 1) [9, 10]. On the other hand, agroindustrial waste suchas fruit rinds and coffee residues possess a rich carbon content which makes themsuitable for the preparation of biosorbent materials or even activated carbon [11, 12].Several methodologies have been reported for preparing these sorbent materials;these include physical and chemical activation treatments (Fig. 2) [13]. For thephysical activation, the raw material undergoes a thermal treatment which removesvolatile compounds producing free interstitial voids [14]. Whereas the chemicalactivation promotes modifications on the surface of the raw materials, generating

2 E. Coutino-Gonzalez et al.

Fig. 1 Schematic representation of synthetic routes used to fabricate zeolites employing industrialwaste as starting materials

Fig. 2 Schematicrepresentation of syntheticroutes used to fabricateactivated carbon materialsutilizing agroindustrial waste

Porous Materials Obtained from Nonconventional Sources Used in Wastewater. . . 3

available adsorption sites. The most common processes are demethylation oflignin –COOCH3 groups, partial depolymerization of hemicellulose, cellulose, andlignin, in which carboxyl groups are generated [15]. Overall, zeolites produced fromindustrial waste and biosorbent materials generated from agroindustrial residues areconsidered an alternative and ecological solution to the waste disposal problem.Moreover, these materials have been successfully utilized in the removal of heavymetals, dyes, phenols, detergents, and pesticides, from polluted water [16–18]. In thefollowing sections, recent advances in the production of zeolites using industrialwaste streams as precursors and biosorbent materials generated from agroindustrialresidues will be addressed, as well as their potential application in wastewatertreatment.

Synthesis of Zeolites Using Nonconventional Precursors

The first attempt to synthesize zeolites (levynite) using the hydrothermal alkalinemethod was carried by St. Claire Deville in 1862 [19]. However, it was until lastcentury that the systematic study of the synthesis of zeolites was initiated by twopioneer researchers: R.M. Barrer and R.M. Milton. Barrer achieved the synthesis ofzeolites P and Q in 1948 [20], whereas Milton set the basis for the synthesis ofzeolites A, B (later know as Na-P zeolite), C (hydroxysodalite), and zeolite X [21].In both cases, the use of high pressures and elevated temperatures was employed toreproduce the natural hydrothermal conditions required for the fabrication of naturalzeolites. To date, there are about 150 synthetic zeolites, and new topologies are beingdiscovered by using the hydrothermal methodology [19].

Nowadays, the hydrothermal method is widely used at industrial scale to fabricatezeolites. The distinctive feature of this technique is that several conditions such astemperature, time, aggregated solid, and alkali molar concentration are modified toobtain a determined zeolite topology (Fig. 1). The main goal of the hydrothermalsynthesis is to transform the chemical and crystalline structures of the startingmaterials, namely, to separate the tetrahedral Si and octahedral Al structures torecrystallize them into Si ([SiO4]

�4) and Al ([AlO4]�5) tetrahedral structures.

The most common starting materials are aqueous solutions of NaOH, NaAl(OH)4,and Na2SiO3. In the first step of the hydrothermal method, the NaOH and NaAl(OH)4solutions are mixed at room temperature; subsequently the formation of a turbid gel isobtained by adding dropwise the silicate source (Na2SiO3) followed by a controlledtemperature increment. The polymerization of the Si species is the responsible of thegel formation in which these Si basic units are composed of many Si and Al oligomers.During the crystallization step, cations, silicates, and aluminates species, assisted byhydroxyl ions (�OH), form an arrangement that ultimately confers the ordered andcrystalline structure to the final zeolite topology [22].

Small nuclei are formed in order to create bigger zeolite crystals (nucleation step)that grow over the crystallization period. At industrial scale the use of “seeds” ishighly common to favored the formation of a certain type of zeolite topology aboveothers, reducing the synthesis time and costs [19]. The final product is a powder


composed of small crystals with sizes ranging between a few and hundreds ofmicrons. The main zeolite properties such as topology, silicon-to-aluminum (Si/Al)ratio, and cavity dimensions, among others, are strongly dependent on the initialsynthesis conditions such as the reactive concentrations, pH, crystallization time,mixing, use of promoters, etc. According to the Oswald successive transformationrule [23], most of the zeolites and minerals phases in general are not in equilibrium,but in metastable states that are subsequently converted into more stable phases.

Due to the dual benefit including the decrease of production costs and thereutilization of waste streams generated in different industrial processes, the use ofindustrial waste streams in the synthesis of zeolites has gained importance over thepast years. Most common waste streams reported in literature that are used inthe fabrication of zeolites are fly ashes produced during the combustion of mineralcarbon [9], heat-treated sludge obtained from wastewater and drinking water plants[7], volcanic material, and natural clay minerals [24].

The main parameters associated to the synthesis of zeolites utilizing wastestreams as precursors have been recently reported [6–10], highlighting the impor-tance of the precursor type and composition (silicon and aluminum content), thepossible existence of interference compounds, reactive amounts (waste, water,NaOH), reactor type (open or close configuration), temperature, and synthesis time.

Hydroxyl consuming ions, in particular Fe species, are the main species that couldinterfere during the synthesis of zeolites employing waste streams [25]. Ball and co-workers demonstrated that the synthesis time for aluminosilicates is shorter than thatrequired for ferrosilicates [26]. This behavior has been also documented by Basaldellaand collaborators [27], where the authors attributed this phenomenon to a decrease inthe crystallization time of zeolites in the presence of Fe species that mainly react withthe alkali species and form insoluble hydroxides which ultimately precipitate, having anegative effect in the availability and uptake of �OH ions that are needed during theformation of the zeolite building blocks during the crystallization step. Furthermore,the use of pretreatments or fusion steps produce more available Fe species that couldbe incorporated into the zeolite crystalline structure through an isomorphic substitu-tion of aluminum by iron, yielding deformations in the zeolite structure affecting theircation exchange properties [25].

Synthesis of Zeolites Using Fly Ashes

Fly ashes (FA) are the most common waste streams employed in the synthesis ofzeolites due to their high amorphous aluminosilicates content, which are solubleunder the typical zeolite synthesis conditions [9, 10]. Besides amorphous alumino-silicates, FA contain significant amounts of quartz, mullite, hematite, calcite, amongother minerals. However, these crystalline aluminosilicates require a pretreatmentdue to their low reactivity under the temperature conditions employed in thesynthesis of zeolites. Such pretreatment consists of the fusion of FA under basicconditions (Fig. 1); NaOH and Na2CO3 are commonly used for this purpose [25, 28].The alkali is responsible for the extraction of Si and Al from the crystalline


aluminosilicates, providing at the same time the counter-balancing ions needed forcompensating the charges in the final zeolite structure. The physicochemical prop-erties of FA make them strongly appealing to be employed in the synthesis ofzeolites, typical (SiO2/Al2O3) molar ratios present in FA range between 1.2 and 3.8.

The temperature utilized in the hydrothermal method ranges between 30 �C and200 �C, the methodologies that use this temperature interval are consider to be eitherlow or moderate approaches [9]. If higher temperatures are used, the resultingzeolites will become more dense and with a higher Si content. In Table 1 acompilation of synthesis conditions to fabricate zeolites using FA as precursors ispresented. Temperature greatly affects the nucleation speed and growth of the zeolitecrystals, and for the case in which FA are used as precursors, temperature has also aneffect on the solubilization of the initial aluminosilicates [28].

By using FA as silicon and aluminum source, the synthesis of zeolites (A, P andX) possessing high cation exchange capacities (CEC) has been demonstrate.Other topologies, such as sodalite, have been also fabricated from FA, however,this topology is mainly employed as model to study the crystallization process ofsodalite-containing zeolites and is poorly used in decontamination process due totheir low pore sizes which hinders their CEC [37].

Synthesis of Zeolites Using Kaolinite and Different Industrial Waste

Kaolinite is a natural mineral that has been mainly utilized to synthesize zeolites withlow Si/Al ratios, such as zeolite A and X [38]. However, prior the synthesis procedure,a thermal treatment is required to convert kaolinite to metakaolinite. Such transfor-mation occurs between 450 �C and 900 �C in a time interval of 1–4 h. Metakaolinite isa dehydroxilated and amorphous form of kaolinite that is more reactive during thesynthesis of zeolites. Such enhanced reactivity is mostly due to a better availability ofSi and Al in metakaolinite caused by thermal treatment and alkaline fusion. On theother hand, zeolites with high Si/Al ratios, such as ZSM-5, have been prepared usingdealuminated matakaolinite. Ghrib and collaborators [39] synthesized ZSM-5 usingdealuminated metakaolinite and modified the SiO2/Al2O3 ratio of the material byadding a colloidal silica solution. The final product displayed quartz traces as mainimpurity. In a different report, Villaquirán-Caicedo and collaborators [40] carried outthe synthesis of zeolites A and X with low Si content using natural kaolin with 40%quartz and iron oxide, as main impurities. The authors reported a high cation exchangecapacity, within the range of 440 cmol/kg for zeolite A, being similar or even superiorto those reported for similar commercial zeolites.

Table 2 presents a summary of synthesis conditions required to fabricate zeolitesutilizing kaolinite as a precursor [42–48]. Regarding the synthesis conditions, Ugaland co-workers [45] reported the synthesis of zeolite A after 4 h of processing thematerials at 90 �C under atmospheric pressure. On the other hand, Bauer andcollaborators [41] used a long synthesis time of 3600 h at temperatures near roomconditions. The process to fabricate zeolites from kaolinite as precursor can besummarized in the following sequence: kaolinite ! activation at 550–900 �C to


Table

1Syn

thesiscond

ition

sto

fabricatezeolitesusingFA

asstartin

gmaterial

Com

positio

n

Main

impu

rities

Activation

Hyd

rothermaltreatm

ent

Produ

ct

Ref.

SiO

2/Al 2O3

ratio

Reagent

Tem

p.(�C)

Tim

e(h)

Tem

p.(�

C)

Tim

e(h)

Alkali

(M)

s/l

(g/m

L)

System

cond

ition

sSyn

thesized

material

Surface

area

(m2/g)

CEC

(meq/

g)

1.56

Fe,Ca

nana

na15

0–20

03–12

00.5–4,

(NaO

H)

0.06

–5C

P,K-F

nr1.11

[29]

1.57

nrna

nana

30–50

24–2

400

3–7

(NaO

H)

0.05

CX

nrnr

[30]

3.26

nrna

nana

40–120

2–72

0.5–4

(NaO

H)

1–4

C OP,Hyd

rox,

Chab

2.4

[31]

1.89

nrNaCO3

830

110

05–13

na0.02

–0.2

nrA,P,X

nr32

–4.6

[28]

1.2–

3.8

Fe(16%

)na

nana

60–150

24–3

360.1–1

0.03

–0.2

CP,Ana,P

h(K

OH),

Gme

nrnr

[32]

2.5

Fe

(rem

oved

by magnetic

treatm

ent)

nana

na85

–120

4–72

2–6

0.1–

0.4

CHyd

rox,

Chab,

A,X

nr3.75

[33]

4.0

Fe

nana

na12

03–24

1–4

(KOH)

0.4

CK-Chab

nr2.00

[34]

2.42

nrNaO

H60

01–2

100

24nr

nrC

X,A

,Sod

91–5

15nr

[35]

1.64

Fe

NaO

H55

01

40–90

24nr

0.01

75–0

.023

5O

A,H

ydrox,

Pnr

2.5

[25]

1.87

Fe,Ca

nana

na75

–105

nr3

0.02

5O

X,P,

Hyd

rox

39–2

312.39

[36]

nano

tapp

licable,nrno

treported,Azeolite

A,A

naanalcime,Phph

illipsite,G

megm

elinite,K

-Fzeolite

K-F,P

zeolite

P,Hydroxhy

drox

ycancrinite,X

zeolite

X,

Cha

bchabazite,So

dsodalite,

Oop

enhy

drotherm

alsystem

,C

closed

hydrotherm

alsystem

,s/lsolid

-to-liq

uidratio

,CEC

catio

nexchange

capacity,Temp

temperature


Table

2Syn

thesiscond

ition

sto

fabricatezeolitesusingkaolinite

asthestartin

gmaterial

Com

positio

n

Principal

impu

rities

Activation

Hyd

rothermaltreatm

ent

Produ

ct

Ref.

SiO

2/Al 2O3

ratio

Reagent

Tem

p.(�C)

Tim

e(h)

Tem

p.(�

C)

Tim

e(h)

Alkali,

(M)

s/l(g/m

L)

System

Syn

thesized

material

Surface

area

(m2/

g)

CEC

(meq/

g)

1.99

nrna

nana

35–8

036

000.1–

4(K

OH)

0.01

25–0

.04

OKI,Ph

nrnr

[41]

2.37

nrna

600–

900

1090

6–24

5(K

OH)

0.03

3O

K-F

200

nr[42]

2nr

na90

00.5

100

1–24

01.33

(NaO

H)

0.06

CA,X

,Y43

03.80

[43]

1.94

nrna

700

1870–8

01–8

1–3

(NaO

H)

0.04

CA

nrnr

[44]

2.59

nrna

550

1.5

904

8(N

aOH)

0.2

OA

nrnr

[45]

1.3

nrNaO

H65

01

25–6

096

nanr

OA,X

nrnr

[46]

1.9

nrNaO

H20

04

908

nanr

OX

326

nr[47]

1.1

S,F

eReducing

atmosph

ere

750–

800

nr55–9

53–11

2(N

aOH)

0.1–0.4

OA,S

od10

6.6

nr[48]

nano

tapplicable,n

rno

trepo

rted,A

zeolite

A,P

hph

illipsite,K

-Izeolite

K-I,K

-Fzeolite

K-F,P

,Xzeolite

X,Y

zeolite

Y,S

odsodalite,Oop

enhy

drotherm

alsystem

,Cclosed

hydrotherm

alsystem

,s/lsolid

liquidratio

,CECcatio

nexchange

capacity,Tem

ptemperature


from metakaolinite ! hydrothermal synthesis to form zeolite A or X. By using thisprocedure other topologies have been synthesized, such as zeolite KI, K-F, andphillipsite.

Other types of waste have been also used to synthesize zeolites. The mostcommon ones are sludge produced in wastewater and drinking water plants, riceash, metallurgic waste, river sediments and volcanic deposits [7, 49–56]. The sharedproperties of the previously mentioned residues is the high Si and Al content, whichis a desired requirement for their use in the fabrication of zeolites. More informationregarding these types of waste as well as zeolite synthesis conditions can be found inTable 3. In all cases, the main goal is to decrease the environmental burden related tothe generation and disposal of such waste, as well as diminishing the productioncosts of zeolites.

Fabrication of Biosorbent Materials and Activated Carbon fromAgroindustrial Waste

Organic agroindustrial waste is mainly composed of hemicellulose, lignin, lipids,proteins, sugar, water, hydrocarbons, and starch; several agroindustrial wastes havedisplayed a high adsorption capacity toward different contaminants, especially thosehaving a considerable cellulose content. The use of natural biological components tofabricate carbon-based materials has been growing rapidly over the past decades.The synthesis of high quality carbon-based materials from agroindustrial wasteopens up alternative ways for the conversion of residues into materials with anadded value [58]. An example is activated carbon, which is often utilized asadsorbent material in decontamination processes.

One of the most popular valorization approaches to reutilize agroindustrial wasteis based on a thermochemical process called “carbonization” (Fig. 2). Carbonizationprocess includes the conversion (using high temperatures) of a macromoleculartridimensional organic system into a macro-atomic network of carbon atoms.Small molecules such as water, methanol, and carbon dioxide are eliminated fromthe organic phase; and the resultant material is converted into a solid carbon-richmaterial (charcoal or biochar). By using this process, highly porous tridimensionalmaterials are formed. This process is ideally controlled through temperature whichregulates the dimensions of the nanoporous cavities [59]. The stages involved in thecarbonization process can be divided in four and are related to the appliedtemperature.

In the first stage (T< 100 �C), biomass is dried at low temperatures to release thesurface humidity; this corresponds to a drying step. Then, in the second stage(100 �C > T < 300 �C), an exothermic dehydration of the biomass takes place,where low molecular gases such as CO and CO2 are released, and essential oilsare distilled. In the third stage (200 �C > T < 600 �C), the decomposition of largebiomolecules occurs. Finally, in the fourth stage (300 �C > T < 900 �C), thecracking of volatile compounds into carbon and non-condensable gases takes


Table

3Syn

thesiscond

ition

sto

prod

ucezeolitesfrom

differenttypesof

residu

eswith

high

SiandAlcontents

Material

SiO

2/Al 2O3

ratio

/im

purities

Activation

Hyd

rothermaltreatm

ent

Produ

ct

Ref.

Reagent

Tem

p.(�C)

Tim

e(h)

Tem

p.(�

C)

Tim

e(h)

Alkali

(M)

s/l(g/m

L)

Pressure

Syn

thesized

material

Surface

area

(m2/g)

CEC

(meq/

g)

Glassytuff

5.72

nana

na10

05

nrnr

nrSod

.nr

nr[49]

Minetailing

2.9–5.0/Fe

Na 2CO3

1000

1210

0–20

0nr

0.25

–1(N

aOH)

0.25

–1(TPA

OH)

nrc

Ana,M

ord,

P,ZSM-5

nrnr

[50]

Glassytuff

4.83

nana

na80

183(N

aOH)

nrO

X,H

Snr

nr[51]

Paper

slud

geandgranite

1.57

nana

na90

243(N

aOH)

0.1–0.4

OHS,P

nr1.27

[52]

Sedim

ents

9.2

NaO

H35

0–75

02

952–24

na0.05–0

.4O

P,X,H

S,A

403.2

[53]

Drink

ing

water

slud

ge1.76

NaO

H55

02

60–85

18–4

8na

0.12–0

.25

OX,S

od,P

425

1.70

[7]

Sludg

eand

slag

2.59

NaO

H70

01

901–9

3(N

aOH)

0.00

2–0.07

7C

A,H

Snr

nr[54]

Wasted

catalysts

1.86

Na 2CO3

800

280

24(N

aOH)

0.03

5C

Anr

nr[57]

Silicon

slud

ge9.15

nana

na90

82.72

(NaO

H)

0.03

5O

X59

0nr

[55]

Riceashand

sodium

alum

inate

16–4

00na

550

nr13

572

3 (TEAOH)

nrAuto

Beta,ZSM-

1267

0nr

[56]

nano

tapp

licable,nrno

treported,Azeolite

A,A

naanalcime,Betazeolite

beta,P

hph

illipsite,G

megm

elinite,K

-Fzeolite

K-F,P

zeolite

P,HShy

drox

ysod

alite,

Xzeolite

X,Cha

bchabazite,Mordmordenite,So

dsodalite,

Oop

enhy

drotherm

alsystem

,C

closed

hydrotherm

alsystem

,s/lsolid

liquidratio

,TEAOH

tetraethylam

mon

ium

hydrox

ide


place. The different stages involved in the carbonization process are highly depen-dent on the starting material utilized [60].

During the pyrolytic carbonization materials could reach temperatures between350 �C and 600 �C, therefore, to have an efficient carbonization process, the biomassmoisture content should be less than 30%. The final product obtained from thisprocess is an activated carbon material that can be employed as adsorbent indecontamination processes.

There are two main activation methods used to maximize the adsorption capacityof the fabricated materials. In the first method, the carbon-based material is modifiedafter its production by using two gasifying agents, namely, carbon dioxide (CO2) andwater vapor (H2O). These agents remove C atoms from the porous carbon structureof the materials according to the following endothermic equations (Eqs. 1 and 2).This activation method is commonly known as “thermal activation.” This method-ology comprises two different stages; in the first stage, the material undergoes athermal treatment with the subsequent opening of the pores that were initiallyblocked or closed (second stage). The resulting material possesses a larger surfacearea due to the presence of a highly porous network.

Cþ CO2 ! 2CO (1)

Cþ H2O ! COþ H2 (2)

The second activation method consist of a chemical modification (Fig. 2) of thecarbonized carbon-based materials using chemical reagents such as phosphoric acid(H3PO4), zinc chloride (ZnCl2), potassium hydroxide (KOH), and potassium car-bonate (K2CO3) [59]. Some of the advantages of chemical activation, compared tothe physical activation, are the low energy costs associated, mainly due to the lowtemperatures used during the process, and a better and more controllable formationof the porous network [61].

Activated carbon obtained through carbonization and chemical activation pro-cesses display characteristic porous networks that are determined by several factorssuch as the starting material, temperature and carbonization periods, heat speed,starting materials particle size, among others. These factors have a strong influencein the final features of the carbon materials prepared, and the use of certain startingmaterials above others will be determined by the final use of the materials [61].A balance between interstitial porous transport and adsorption capacities of activatedcarbon materials is crucial for the correct performance of the material. Ideally,adsorbates should freely travel from the inside of the material to its surface;moreover, the porous network of the activated carbon material should also possessa high adsorption capacity.

Activated carbon materials are produced from a wide variety of carbon-basedproducts. The most commonly used are inorganic materials rich in carbon such ascoal, lignite, and wood. Among these, coal is by far the most common usedprecursor; however, agroindustrial waste is nowadays considered an alternativeoption. The use of agroindustrial residues for the fabrication of activated carbonrepresents a good alternative to conventional precursors reducing the environmental


burden of forests. Several agroindustrial residues such as coconut shell, sorghum,coffee beans hulls, sawdust, and chestnut wood have been proposed as potentialstarting materials for the fabrication of activated carbon due to their high carbon andlow ash content. Furthermore, agroindustrial residues are considered promisingstarting materials for the fabrication of activated carbon due to their abundanceand low cost [61].

Nowadays, activated carbon materials are heavily used in the control of atmo-spheric pollution and wastewater treatment in developing countries. However,emerging applications have been pointed out for these materials, such as in thetreatment of industrial gases, water purification processes, odor control, amongothers. Therefore, the quest for adequate starting materials to produce selectiveand low-cost activated carbon materials is of vital importance. Over the past years,activated carbon materials with molecular sieve properties have been synthesized toperform the selective adsorption of molecules with specific sizes and natures, evencompeting with zeolite-based materials, which are commonly used in these pro-cesses. Another example of the great potential of activated carbon materials withmolecular sieve properties is in the capture of nitrogen oxides (NOx), sulfur dioxide(SO2), hydrogen sulfide (H2S), and carbon sulfide (CS2), which are commonlyproduced during the combustion of fossil fuels.

Activated carbon materials are commonly used as adsorbents due to their highadsorption capacity, microporous volume, regeneration facility, and high surfaceareas [61]. Typical surface area data for activated carbon in literature range from 100to 5000 m2/g. Therefore, activated carbon materials with surface areas higher than1500 m2/g are considered good adsorbent materials.

There is evidence that supports the use of bone and olive pomace, olive wood,almond peel, peach bone, plum bone, apricot bone, and cherry bone in the fabrica-tion of granular activated carbon materials with similar characteristics to those ofcommercially available activated carbon used at industrial scale. The low cost andabundance of such agroindustrial residues make them very appealing to be used asstarting materials in the fabrication of activated carbon.

The use of alternative starting materials based on agroindustrial residues opens upinteresting research areas in the field of waste stream valorization; this is highlybeneficial and appealing due to their low cost, high abundance, and environmentalburden decrease. Surface areas for activated carbon materials (based on orange peel)reported in literature range between 248 m2/g, 1090 m2/g, 1203 m2/g, and 1477 m2/g[14, 15].

A summary of different agroindustrial residues used in the fabrication of activatedcarbon materials, as well as their synthesis parameters and surface areas is presentedin Table 4. Activated carbon materials fabricated by chemical activation using fruitrinds display high surface areas, similar to those reported for commercial materialssuch as lignite (1300, 1853 m2/g) [65], PET (1170 m2/g) [66], Darco KB-B(1608 m2/g) [67], Fluka 05120 (1110 m2/g) [67], MT40 carbon (528 m2/g) [67],BW carbon (300 m2/g) [68], and Fluka 03866 (179 m2/g) [67].


Table

4Sum

maryof

theprop

ertiesof

agroindu

strialresidu

esused

inthefabricationof

activ

ated

carbon

Materiala

Particle

size

Carbo

nizatio

n

Activation

Reagent

Tem

p.(�C)

Tim

e(h)

Surface

area

(m2/g)

Pore

volume

(cm

3/g)

Pore

size

(nm)

Adsorption

capacity

(mg/g)

Ref.

Tem

p.(�C)

Tim

e(h)

Atm

.

Grape

fruit

nr45

02

N2

Chemical

KOH

450

1.5

1892

.11.09

51.92

680

[62]

800

2.5

Banana

nr10

008

N2

Chemical

ZnC

l 2nr

nr16

501.26

3.01

nr[63]

Jackfruit

nr35

00.75

N2

Chemical

H3PO4

350

0.5

5nr

nrnr

[61]

450

0.5

1033

0.66

41.7

nr

550

0.5

1260

0.73

32

nr

Alm

ond

1–5mm

300

1N2

Phy

sical

CO2

nr1

322

19.5

8–12

288.5

[14]

700

1nr

138

516

.92

10

1200

1nr

134

215

.515

–25

Orang

e1–

5mm

300

1N2

Phy

sical

CO2

nr1

225.6

14.5

7–14

166.7

[14]

700

1nr

124

815

10

1200

1nr

124

013

.512

–14

Rice

6.3μm

650

1N2

Chemical

NaO

Hnr

–25

3.4

0.17

2.62

0.17

[64]

a Con

sidering

only

fruitrind

sandgrainshells;Atm

atmosph

ere,nr

notrepo

rted,T

emptemperature


Usage of Zeolites and Activated Carbon Obtained fromNonconventional Sources in Wastewater Treatment Processes

Zeolites fabricated from industrial waste are good candidates to remove heavymetals from wastewater because of their high cation exchange capacity (CEC),especially those topologies having low Si/Al ratios such as zeolite A, X, and P.The negative framework charge created by aluminum is compensated by alkaline oralkaline earth cations such as Na+, K+, Mg2+, and Ca2+. These species occupy aspecific site close to the [AlO4] tetrahedral and can be replaced by metallic ions suchas Pb2+, Cd2+, Cu2+, Fe2+, among others. Nevertheless, it is important to considerdiffusion processes that take place inside the zeolites porous network, which dictatethe heavy metals uptake, and thus playing a major role in the design of wastewatertreatment processes. For this last particular purpose, zeolites with large porous sizesare preferred because they allow the free intraparticle diffusion of metals.For instance, zeolites A and X synthesized from fly ash have been successfullyemployed in the removal of Cs+ (which is considered a nuclear radioactive pollutant)from wastewater, displaying a maximum capacity of 1.02 meq/g [6]. The removal ofnuclear radioactive pollutants from wastewater using zeolites fabricated from indus-trial waste has gained importance in recent years [69].

Zeolites obtained from industrial waste can also be used as adsorbents to removeanions and organic pollutants from wastewater. Nevertheless, zeolites shouldundergo a surface modification, which consist of the incorporation of tensoactiveagents on their surface, to carry anionic exchanges. For instance, Xie and collabo-rators achieved the synthesis of fly ash-derived zeolites [70], which was subse-quently modified with a tensoactive agent to remove phosphate, methylene blue,humic acid, and bisphenol A from contaminated water, with promising results.The maximum adsorption capacity of these pollutants increased considerablywhen the zeolite surface was functionalized with cetyltrimethylammonium bromide(CTAB). By following this approach, the removal of chromates, iodides, arsenates,arsenites, molybdates, and tungstate, from mines drainages, has been demonstrated[24, 43, 71], opening up new avenues for the use of fly ash-derived zeolites inwastewater treatment.

Besides the previously discussed applications, zeolites fabricated from industrialwaste have displayed potential as nutrient sequestration in anaerobically digestedswine wastewater (ADSW). For instance, XiaoYan and co-workers synthesized anano-zeolite from fly ash that was used in the simultaneous sequestration of ammo-nium and phosphate from ADSW. For both contaminants they obtained removalefficiencies ranging from 41 up to 98% [72]. A similar report was published byCardoso and collaborators [73], where zeolite P obtained from coal fly ash was usedin the treatment of swine wastewater, resulting in a high removal capacity for totalammoniacal nitrogen. As it can be observed in the previous examples, zeolitesproduced from industrial waste are quite versatile, therefore, these materials can beused to remove a wide variety of contaminants present in polluted water.However, several factors, such as the zeolite affinity, type of pollutant, availabilityof exchange sites, and impurities present in the zeolites, among others, should be


taken into consideration during the design of wastewater treatment processes involv-ing zeolites fabricated from industrial waste.

Activated carbon produced from agroindustrial residues as starting materials is aversatile adsorbent that has been used in the treatment of effluents, resulting in theremoval of pollutants such as heavy metals [74], anions [75], dyes [76], phenols[77], detergents [78], pesticides [79], and humic compounds [80], among others.These emerging porous materials represent an alternative to commercial activatedcarbon, with the extra advantage of minimizing the overall economic and ecologicimpact related to their fabrication.

For instance, Iqbal and collaborators reported a mango peel-based sorbent for theremoval of Cd2+ and Pb2+ from aqueous solution [74], which displayed a maximumadsorption capacity for Cd2+ and Pb2+ of 68.92 and 99.05 mg/g, respectively. In thisstudy, the sorption kinetics of both metals were analyzed and followed a pseudo-second order and Langmuir adsorption models. Further analysis of the sorbentmaterials revealed that carboxyl and hydroxyl functional groups were mainlyresponsible for the sorption properties of the investigated metals.

Gupta and co-workers studied the sorption of fluoride on waste carbon slurryobtained from a fuel oil-based generator of a fertilizer company [79]. The maximumfluoride adsorption capacity (4.861 mg/g) was obtained when 1.0 g/L of adsorbentmaterial was employed. In this study, several parameters such as contact time, pH,temperature, and adsorbent dose were analyzed. Interestingly, the authors observedthat pore diffusion was the rate-controlling step of the adsorption. Besides thisapplication, carbon-based adsorbent obtained from nonconventional sources havebeen successfully used in the treatment of wastewater polluted with synthetic dyes,such as Poly R-478, Remazol Brilliant Blue R, rhodamine B, crystal violet, Sudan I,Congo red, acid orange 7, indigo carmine, and reactive black, among others [76].

Ahmaruzzaman and collaborators analyzed the use of coal, residual coal, andresidual coal treated with H3PO4 in the removal of phenolic compounds fromwastewater [77]. In this report, the effect of several parameters such as pH, contacttime, and temperature was investigated, as well as the adsorption models. The resultsshowed that the removal of phenol followed a Lagergren first-order kinetic model.Granular activated carbon and carbon black have also been used in the removal ofbromate from drinking water [75] and cationic surfactants such as cetyltrimethy-lammonium bromide (CTAB) in wastewater [78].

Although the use of zeolites and activated carbon obtained from (agro)industrialin wastewater treatment processes has been explored separately, there have beenattempts to fabricate composite materials of activated carbon and zeolites. Thisapproach consists in growing a zeolite film on the surface of porous carbon supports,so the final product may display the functional properties of both materials.A representative example is the approached followed by Miyake and collaborators[81], where composite materials made of activated carbon-zeolite were fabricatedusing coal fly ash with different carbon contents. These hybrid materials were thenutilized in the removal of toxic metal ions such as Pb2+, Cu2+, Cd2+, and Ni2+,displaying uptake capacities of 2.65, 1.72, 1.44, and 1.20 mmol/g, respectively.


Conclusions and Future Perspectives

In this chapter, we discussed about novel synthetic approaches to fabricate functionalporous materials using (agro)industrial wastes (nonconventional sources). Morespecifically, the production of zeolites using industrial waste streams as precursorsand biosorbent materials fabricated from agroindustrial waste was addressed, as wellas their potential use in wastewater treatment.

Strategies that comprise the production of zeolites from industrial waste andbiosorbent materials fabricated from agroindustrial residues are considered feasiblealternatives to provide ecological solutions to the waste disposal problem. Further-more, the fabricate materials (zeolites and biosorbents) have been successfully

Fig. 3 Schematic representation of a valorization approach to use (agro)industrial waste in thefabrication of porous materials (zeolites, biosorbents) with applications in wastewater treatmentprocesses


utilized in the removal of heavy metals, dyes, phenols, nutrients, detergents, andpesticides from wastewater. However, more research has to be conducted on theseemerging materials to understand several processes related to their formation mech-anisms and pollutants uptake, to optimize their properties and ultimately generaterational design protocols to produce more efficient materials with targeted function-alities. Moreover, methodologies for quantifying the impact of the life cycle (Fig. 3)of such materials in the environment should be developed, to assess the real effectthat this emerging technology could have on the environment and determine if thesematerials can be certainly categorized as eco-materials, which will further supportpolicy making toward a sustainable development.

References

1. Halada K (2003) Progress of ecomaterials toward a sustainable society. Curr Opin Solid StateMater Sci 7:209–216

2. Umezawa O, Shinohara Y, Halada K (2014) New aspects of ecomaterials from the viewpoints ofthe consumer and regional communities. Mater Trans 55:745–749

3. Halada K, Yamamoto R (2001) The current status of research and development on eco-materialsaround the world. MRS Bull 26:871–878

4. Yagi K (2000) Materials development for sustainable society – ecomaterials. In: Proceedings ofthe international symposium on ecomaterials held in conjunction with the 39th annual confer-ence of metallurgist of CIM Ottawa, Ontario, Canada, 3–13

5. Koltum P (2010) Materials and sustainable development. Prog Nat Sci 20:16–296. Shih W-H, Chang H-L (1996) Conversion of fly ash into zeolites for ion-exchange applications.

Mater Lett 28:263–2687. Espejel-Ayala F, Schouwenaars R, Duran-Moreno A, Ramirez-Zamora RM (2014) Use of

drinking water sludge in the production process of zeolites. Res Chem Intermed 40:2919–29288. Espejel-Ayala F, Chora-Corella R, Morales-Perez A, Perez-Hernandez R, Ramirez-Zamora RM

(2014) Carbon dioxide capture utilizing zeolites synthesized with paper sludge and scrap-glass.Waste Manag Res 32:1219–1226

9. Querol X, Moreno N, Umana JC, Alastuey A, Hernandez E, Lopez-Soler A, Plana F (2002)Synthesis of zeolites from coal fly ash: an overview. Int J Coal Geol 50:413–423

10. Wdowin M, Franus M, Panek R, Badura L, Franus W (2014) The conversion technology of flyash into zeolites. Clean Techn Environ Policy 16:1217–1223

11. Boonamnuayvitaya V, Sae-ung S, Tanthapanichakoon W (2005) Preparation of activatedcarbons from coffee residue for the adsorption of formaldehyde. Sep Purif Technol 42:159–168

12. Gao JJ, Kong DD, Wang YF, Wu J, Sun SL, Xu P (2013) Production of mesoporous activatedcarbon from tea fruit peel residues and its evaluation of methylene blue removal from aqueoussolutions. Bioresources 8:2145–2160

13. Rodriguez-Reinoso F, Molina-Sabio M (1992) Activated carbons from lignocellulosic materialsby chemical and/or physical activation: and overview. Carbon 30:1111–1118

14. Hashemian S, Salari K, Yazdi A (2014) Preparation of activated carbon from agricultural wastes(almond shell and orange peel) for adsorption of 2-pic from aqueous solution. J Ind Eng Chem20:1892–1900

15. Xie Z, Guan W, Ji F, Song Z, Zhao Y (2014) Production of biologically activated carbon fromorange peel. J Chemother 2014:1–9

16. Bhatnagar A, Sillanpaa M (2010) Utilisation of agro-industrial and municipal waste as potentialadsorbents for water treatment – a review. Chem Eng J 157:277–296

17. Koshy N, Singh DN (2016) Fly ash zeolites for water treatment applications. J Environ ChemEng 4:1460–1472


18. Sun Z, Li C, Wu D (2010) Removal of methylene blue from aqueous solution by adsorptiononto zeolite synthesized from coal fly ash and its thermal regeneration. J Chem TechnolBiotechnol 85:845–850

19. Cundy CS, Cox PA (2003) The hydrothermal synthesis of zeolites: history and developmentfrom the earliest days to the present time. Chem Rev 103:663–701

20. Barrer RM (1948) Synthesis of a zeolitic mineral with chabazite-like sorptive properties.J Chem Soc 0:127–132

21. Milton RM (1959) US Patent 2,882,24322. Barrer RM (1982) Hydrothermal chemistry of zeolites. Academic, New York, pp 360–36523. Ostwald W (1896) Lehrbuch der Allgemeinen Chemie. Engelmann, vol 2, part 1. Leipzig24. Ríos C, Williams CD, Roberts CL (2008) Removal of heavy metals from acid mine drainage

(AMD) using coal fly ash, natural clinker and synthetic zeolites. J Hazard Mater 156:23–3525. Molina A, Poole C (2004) A comparative study using two methods to produce zeolites from fly

ash. Miner Eng 17:167–17326. Ball WJ, Dwyer J, Garforth AA, Smith WJ (1986) The synthesis and characterization of iron

silicate molecular sieves. Stud Surf Sci Catal 28:137–14427. Basaldella EI, Torres RM, Tara JC (1998) Iron influence in the aluminosilicate zeolites

synthesis. Clay Miner 46:481–48628. Yaping Y, Xiaoqiang Z, Weilan Q, Mingwen W (2008) Synthesis of pure zeolites from

supersaturated silicon and aluminum alkali extracts from fused coal fly ash. Fuel 87:1880–188629. Juan R, Hernández S, Andrés JM, Ruiz C (2007) Synthesis of granular zeolitic materials with

high cation exchange capacity from agglomerated coal fly ash. Fuel 86:1811–182130. Gross M, Soulard M, Caullet P, Patarin J, Saude I (2007) Synthesis of faujasite from coal fly

ashes under smooth temperature and pressure conditions: a cost saving process. MicroporousMesoporous Mater 104:67–76

31. Wu D, Sui Y, Chen X, He S, Wang X, Kong H (2008) Changes of mineralogical-chemicalcomposition, cation exchange capacity, and phosphate immobilization capacity during thehydrothermal conversion process of coal fly ash into zeolite. Fuel 87:2194–2200

32. Querol X, Alastuey A, Fernández-Turiel JL, López-Soler A (1995) Synthesis of zeolites byalkaline activation of ferro-aluminous fly ash. Fuel 74:1226–1231

33. Poole C, Pritajama H, Rice N (2000) Synthesis of zeolites adsorbents by hydrothermal treatmentof PFAwastes: a comparative study. Miner Eng 13:831–842

34. Murayama N, Takahashi T, Shuku K, Lee H, Shibata J (2008) Effect of reaction temperature onhydrothermal synthesis of potassium type zeolites from coal fly ash. Int J Miner Process87:129–133

35. Somerset VS, Petrik LF, White RA, Klink MJ, Key D, Iwuoha E (2003) The use of X-rayfluorescence (XRF) analysis in predicting the alkaline hydrothermal conversion of fly ashprecipitates into zeolites. Talanta 64:109–114

36. Derkowski A, Franus W, Beran E, Czimerova A (2006) Properties and potential applications ofzeolitic materials produced from fly ash using simple method of synthesis. Powder Technol166:47–54

37. Watanabe Y, Yamada H, Tanaka J, Komatsu Y, Moriyoshi Y (2004) Ammonium ion exchangeof synthetic zeolites: the effect of their open-window sizes, pore structures, and cation exchangecapacities. Sep Sci Technol 39:2091–2104

38. Ghrib Y, Frini-Srasra N, Srasra E (2016) Synthesis of NaX and NaY zeolites from Tunisiankaolinite as base catalysts: an investigation of Knoevenagel condensation. J Chin Chem Soc63:601–610

39. Ghrib Y, Frini-Srasra N, Srasa E (2017) Synthesis of ZSM-5 zeolite from metakaolinite: effectsof the SiO2/Al2O3 molar ratio, the initial precursor and the presence of organic template agent.Surf Eng Appl Electrochem 53:64–70

40. Villaquirán-Caicedo MA, De Gutiérrez RM, Gordillo M, Gallego NC (2016) Synthesis ofzeolites from a low-quality Colombian kaolin. Clay Clay Miner 64:75–85


41. Bauer A, Velde B, Berger G (1998) Kaolinite transformation in high molar KOH solutions.Appl Geochem 13:619–629

42. Belver C, Bañares MA, Vicente MA (2004) Materiales con propiedades tecnológicas obtenidospor modificación química de un caolín natural. Bol Soc Esp Ceram Vidrio 43:148–154

43. Covarrubias C, García R, Arriagada R, Yanez J, Garland MT (2006) Cr(III) exchange onzeolites obtained from kaolin and natural mordenite. Microporous Mesoporous Mater88:220–231

44. Youssef H, Ibrahim D, Komarneni S (2008) Microwave-assisted versus conventional synthesisof zeolite a from metakaolinite. Microporous Mesoporous Mater 115:527–534

45. Ugal JR, Hassan KH, Ali IH (2010) Preparation of type 4A zeolite from Iraqi kaolin: charac-terization and properties measurements. J Assoc Arab Univ Basic Appl Sci 9:2–5

46. Belciso C, Cavalcante F, Lettino A, Fiore S (2013) A and X-type zeolites synthesized fromkaolinite at low temperature. Appl Clay Sci 80-81:162–168

47. Ma Y, Yan C, Alshameri A, Qiu X, Zhou C, Li D (2014) Synthesis and characterization of 13Xzeolite from low-grade natural kaolin. Adv Power Technol 25:495–499

48. Wang W, Feng Q, Liu K, Zhang G, Liu J, Huang Y (2015) A novel magnetic 4A zeoliteadsorbent synthesized from kaolinite type pyrite cinder (KTPC). Sol State React 39:52–58

49. Sudo T, Matsuoka M (1958) Artificial crystallization of volcanic glass to sodalite and zeolitestructure. Geochim Cosmochim Acta 17:1–5

50. Gilbert JE, Mosset A (1998) Large crystals of mordenite and MFI zeolites. Mater Res Bull33:997–100334

51. Novembre D, Di Sabatino B, Gimeno D, Garcia-Valles M, Martínez-Manent S (2004) Synthesisof Na-X zeolites from tripolaceous deposits (Crotone, Italy) and volcanic zeolitised rocks (Vicovolcano, Italy). Microporous Mesoporous Mater 75:1–11

52. Wajima T, Haga M, Kuzawa K, Ishimoto H, Tamada O, Ito K, Nishiyama T, Downs RT,Rakovan JF (2005) Zeolite synthesis form paper sludge ash at low temperature (90 �C) withaddition of diatomite. J Hazard Mater 132:244–252

53. Wu D, Lu Y, Kong H, Ye C, Jin X (2008) Synthesis of zeolite from thermally treated sediment.Ind Eng Chem Res 47:295–302

54. Anuwattana R, Khummongkol P (2009) Conventional hydrothermal synthesis of Na-A zeolitefrom cupola slag and aluminum sludge. J Hazard Mater 166:227–232

55. Hiraki T, Nosaka A, Okinaka N, Akiyama T (2009) Synthesis of zeolite-X from waste metals.ISIJ Int 49:1644–1648

56. Lohia S, Prayoonpokarach S, Songsiriritthigun P, Wittayakun J (2009) Synthesis of zeolite betawith pretreated rice husk silica and its transformation to ZSM-12. Mater Chem Phys115:637–640

57. Basaldella EI, Torres Sánchez RM, Conconi MS (2009) Conversion of exhausted fluid crakinginto zeolites by alkaline fusion. Appl Clay Sci 42:611–614

58. Rocco FR, Savastano H, Fiorelli J (2015) Non-conventional building materials based on agro-industrial wastes, 1st edn. Tiliform, Bauru, Sao Paulo, Brazil p 179–218

59. Ahmedna M, Marshall WE, Rao RM (2000) Production of granular activated carbons fromselect agricultural by-products and evaluation of their physical, chemical and adsorptionproperties. Bioresour Technol 71:113–123

60. Demirbas A, Arin G (2002) An overview of biomass pyrolysis. Energy Sources 24(5):471–48261. Prahas D, Kartika Y, Indraswati N, Ismadji S (2008) Activated carbon from jackfruit peel waste

by H3PO4 chemical activation: pore structure and surface chemistry characterization.Chem Eng J 140:32–42

62. Li H, Sun Z, Zhang L, Tian Y, Cui G, Yan S (2016) A cost-effective porous carbon derived frompomelo peel for the removal of methyl orange from aqueous solution. Colloids Surf APhysicochem Eng Asp 489:191–199

63. Lv Y, Gan L, Liu M, Xiong W, Xu Z, Zhu D, Wright DS (2012) A self-template synthesis ofhierarchical porous carbon foams based on banana peel for supercapacitor electrodes. J PowerSources 209:152–157


64. Taha MF, Ibrahim MHC, Shaharun MS, Chong FK (2012) Adsorptive removal of Zn(II) ionfrom aqueous solution using rice husk-based activated carbon. AIP Conf Proc 1482:252–257

65. Montané D, Torné-Fernández V, Fierro V (2005) Activated carbons from lignin: kineticmodeling of the pyrolysis of Kraft lignin activated with phosphoric acid. Chem Eng J 106:1–12

66. László K, Podkoscielny P, Dabrowski A (2003) Heterogeneity of polymer-based activecarbons in adsorption of aqueous solutions of phenol and 2,3,4-trichlorophenol.Langmuir 13:5287–5294

67. Schwickardi M, Johann T, Schmidt W, Schüth F (2002) High-surface-area oxides obtained byan activated carbon route. Chem Mater 9:3913–3919

68. Podkościelny P, Dąbrowski A, Marijuk OV (2003) Heterogeneity of active carbons in adsorp-tion of phenol aqueous solutions. Appl Surf Sci 205:297–303

69. Noli F, Buema G, Misaelides P, Harja M (2015) New materials synthesized from ash undermoderate conditions for removal of toxic and radioactive metals. J Radioanal Nucl Chem303:2303–2311

70. Xie Q, Lin Y, Wu D, Kong H (2017) Performance of surfactant modified zeolite/hydrouszirconium oxide as a multi-functional adsorbent. Fuel 203:411–418

71. Meher AK, Das S, Rayalu S, Bansiwal A (2016) Enhanced arsenic removal from drinking waterby iron-enriched aluminosilicate adsorbent prepared from fly ash. Desalin Water Treat57:20944–20956

72. Chen X, Wendell K, Jun Z, Li J, Yu X, Zhang Z (2012) Synthesis of nano-zeolite from coal flyash and its potential for nutrient sequestration from anaerobically digested swine wastewater.Bioresour Technol 110:79–85

73. Cardoso MA, Horn MB, Ferret LS, Azevedo CMN, Pires M (2015) Integrated synthesis ofzeolites 4A and Na-P1 using coal fly ash for application in the formulation of detergents andswine wastewater treatment. J Hazard Mater 287:69–77

74. Iqbal M, Saeed A, Zafar SI (2009) FTIR spectrophotometry, kinetics and adsorption isothermsmodeling, ion exchange, and EDX analysis for understanding the mechanism of Cd2þ andPb2þ removal by mango peel waste. J Hazard Mater 164:161–171

75. Bao ML, Griffini O, Santianni D, Barbieri K, Burrini D, Pantani F (1999) Removal of bromateion from water using granular activated carbon. Water Res 33:2959–2970

76. Forgacs E, Cserháti T, Oros G (2004) Removal of synthetic dyes from wastewaters: a review.Environ Int 30:953–971

77. Ahmaruzzaman M, Sharma DK (2005) Adsorption of phenols from wastewater. J ColloidInterface Sci 287:14–24

78. Bele M, Kodre A, Arcon I, Grdadolnik J, Pejovnik S, Besenhard JO (1998) Adsorption ofcetyltrimethylammonium bromide on carbon black from aqueous solution. Carbon36:1207–1212

79. Gupta VK, Ali I, Saini VK (2007) Defluoridation of wastewaters using waste carbon slurry.Water Res 41:3307–3316

80. McCreary JJ, Snoeyink VL (1980) Characterization and activated carbon adsorption of severalhumic substances. Water Res 14:151–160

81. Jha VK, Matsuda M, Miyake M (2008) Sorption properties of the activated carbon-zeolitecomposite prepared from coal fly ash for Ni2+, Cu2+, Cd2+ and Pb2+. J Hazard Mater160:148–153


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