13

Chapter 2

REVIEW OF LITERATURE

Metals have played a critical role in industrial development and technological advances of

modern society. Most metals are not destroyed; indeed, they are accumulating at an

accelerated pace, due to the ever-growing industrialization. The major toxic metal ions

hazardous to humans as well as other forms of life are Cr, Fe, Se, V, Cu, Co, Ni, Cd, Hg, As,

Pb, Zn, etc. These heavy metals are of specific concern due to their toxicity, bio-

accumulation tendency and persistency in nature [Friberg and Elinder, 1985; Garg et al.,

2007; Randall et al., 1974]. In the past several disasters became natural evidences of metal

toxicity in aquatic streams such as Minamata tragedy due to Methyl Mercury contamination

and “Itai-Itai” by the contamination of Cadmium in Jintsu river of Japan [Friberg and Elinder,

1985; Kjellstrom et al., 1977]

Rising health problems and its concern have motivated the researchers and academicians to

find the solutions that would be helpful in the sequestering of these toxic metals from aquatic

streams. The real impetus for improvements came in the 1950s and 1960s as a result of

modification of the legislation and setting up of independent pollution prevention authorities

at global level. Conventional methodologies like chemical precipitation, ion exchangers,

chemical oxidation/reduction, reverse osmosis, electro dialysis, ultra filtration, etc. [Gardea-

Torresdey et al., 1998; Patterson, 1985; Zhang et al., 1998] were applied for the sequestering

of heavy metals from aquatic streams. However, these conventional techniques have their

own inherent limitations such as less efficiency, sensitive operating conditions, and

production of secondary sludge and further the disposal are a costly affair [Ahluwalia and

Goyal, 2005a]. Due to the problems mentioned above, research was intensified to look for

14

alternative options to replace the costly and conventional methods. In last decade attention

has been diverted towards the utilization of waste materials which are byproducts or the

wastes from large scale industrial as well as agricultural operations. The extensive literature

survey reveals the various options that have been explored by researchers in the removal

process of heavy metals.

2.1 Potential of Microbial Biomass for Heavy Metal Removal

High metal sorbing substrates such as bacterial, fungal and algal biomasses were explored in

dead / inactive or in live form to remove heavy metals. Considerable potential was proved by

various researchers for these naturally occurring and abundantly available small creatures.

[Volesky, 1988 and 1994; Gadd, 1988; Paknikar et al., 1993] Many bacterial species (e.g.

Bacillus, Pseudomonas, Streptomyces, Escherichia, Micrococcus etc.), were tested for metal

uptake. Algae was considered very promising sorbing agents [Volesky and Tsezos, 1981;

deRome et al., 1987; Luef et al., 1991] because of their prominent sorption capability and

were readily available copiously in seas and oceans [Brady et al., 1993; Puranik et al., 1997].

Qian et al. (2002) investigated the removal of Ni from solutions by Pseudomonas alcaliphila.

It was inferred that the addition of an excess amount of citrate encouraged the complex

degradation as well as Ni removal. Sahin and Ozturk (2005) evaluated the biosorption studies

of Cr (VI) on dried vegetative cell and spore–crystal mixture of Bacillus

thuringiensis var. Thuringiensis using the batch method as a function of pH, initial metal ion

concentration and temperature. The optimum pH observed for Chromium (VI) ions was

2.0. Chromium (VI) ions uptake of B. Thuringiensis spore–crystal mixture was 24.1%,

whereas its vegetative cell metal uptake was found 18.0%. Chojnacka et al. (2005) studied

that blue green algae Spiruline sp. was found capable of adsorbing one or more heavy metals

including K, Mg, Ca, Fe, Sr, Co, Cu, Mn, Ni, V, Zn, As, Cd, Mo, Pb, Se, Al in addition to the

15

biosorption of Cr3+, Cd2+ and Cu2+ ions. Lu et al. (2006) reported that the biomass

of Enterobacter sp. J1 isolated from a local industrial wastewater treatment plant was found

very effective for the sequestering of Pb, Cu and Cd ions. The sp. was able to uptake over

50 mg of Pb per gram of dry cell, while having equilibrium adsorption capacities of 32.5 and

46.2 mg/g dry cell for Cu and Cd, respectively.

Congeevaram et al. (2007) isolated heavy metal resistant bacteria from the soil samples of an

electroplating industry, and the bioaccumulations of Cr (VI) and Ni (II) by isolates were also

investigated. The optimum pH 7 indicated the applicability of the isolated Micrococcus sp.

for the removal of Cr (VI) and Ni (II). Bai and Abraham (2008) explored the use of powdered

biomass of R. nigricans at optimum pH 2, stirring speed of 120 rpm, temperature of 450C and

contact time of 30 minutes and results indicated the high adsorption at low initial

concentrations. Shen et al. (2009) synthesized diethylenetriamine-bacterial cellulose (EABC)

by amination with diethylenetriamine on bacterial cellulose (BC) for the adsorption

properties of Cu (II) and Pb (II) and optimization studies were also carried out. Pseudo-

second-order rate model was well fitted and adsorption isotherm was described by the

Langmuir model.

The ability of biofilm of Escherichia coli supported on kaolin to remove Cr (VI), Cd (II), Fe

(III) and Ni (II) from aqueous solutions was investigated in batch assays for the treatment of

diluted aqueous solutions by Quintelas et al. (2009). The biosorption performance, in terms of

uptake, followed the sequence of Fe (III) > Cd (II) > Ni (II) > Cr (VI). Guo et al. (2010)

studied heavy metal bioremediation by a multi-metal resistant endophytic bacteria L14 (EB

L14) isolated from the Cadmium hyper accumulator Solanum nigrum L. and was

characterized for its potential application in metal treatment. Within 24 h incubation, EB L14

could specifically uptake 75.78%, 80.48%, 21.25% of Cd (II), Pb (II) and Cu (II) under the

initial concentration of 10 mg/L. Bail et al. (2010) reported biosorption studies of heavy

16

metals by whole mycelia of A. niger, R. orysae and Mucar rouxi for the removal of Cd, Ni

and Zn. The efficiency was found to be enhanced by treating the cell wall fractions with 4 M

NaOH at 120oC. Sahin et al. (2012) used Aspergillus tamari for the potential removal of Cd

(II), Mn (II), Ni (II), Pb (II) and Zn (II) heavy metal ions. Adsorption equilibrium was

obtained at 150 min contact time with optimized parameters of pH, stirring speed and

temperature.

Sen (2011) studied the sequestration of Cr (VI) from aqueous solution in a batch bioreactor

by using the resting cells of Fusarium solani. The maximum Cr (VI) removal was 60 mg/L

achieved at 500 mg/L initial Cr (VI) concentration using 36 h old resting cells at optimum pH

2. Kavita and Kehria (2012) reported the potential of acid treated biomass of Trichoderma for

removal of Cr (VI) from electroplating industrial effluents. Acid-treated biomass of T. gamsii

showed a maximum biosorption capacity of 44.8 mg/g. Recently Naid et al. (2014) explored

biosorption properties of algae Laurencia papillosa as a function of pH, temperature and

concentration of algal dosage. The Cadmium (II) uptake by the biosorbent was best described

by pseudo-second-order rate and Langmuir isotherm curve provide more suitable results with

respect to the Freundlich isotherm curve.

2.2 Performance of Agricultural Waste Biomass for Metal Removal

Application of agricultural waste materials as biosorbents for removal of heavy metals

had been employed in various forms world widely by various researchers and scientists.

Whether studies have involved synthetic metal ion solutions or real industrial wastewater

loaded with heavy metal ions, agricultural waste materials have been demonstrated as the best

cheap, reusable, and sustainable choice in a competition with synthetic-chemical-based,

technology-intensive options. Removal of heavy metal ions from the aqueous streams by

agricultural waste materials is an innovative and promising technology. The efficiency of the

17

waste material depends upon the capacity, affinity, and specificity including physico-

chemical nature. The adsorbents were taken either in the natural form, or modified by

chemical and thermal treatment. Agricultural materials, particularly those containing

cellulose showed a potential metal biosorption capacity. The basic components of the

agricultural waste biomass include hemi-cellulose, lignin, extractives, lipids, proteins, simple

sugars, water, hydrocarbons, starch containing a variety of functional groups that facilitates

metal complexation which helps for the sequestering of heavy metals [Bailey et al., 1999;

Sud et al., 2008; Hashem et al., 2005a, b, 2007].

2.2.1 Potential of Agricultural Waste Biomass for Removal of Cr (VI)

Chromium is toxic heavy metal being released into the environment by applications

like tanning, wood preservation and pigments, dyes for plastic, paints, and textiles.

Chromium occurs in a number of oxidation states, but Chromium (VI) and Chromium (III)

are of main environmental concern [Yu et al., 2000]. Extensive work has been reported for

the removal of Chromium employing waste agricultural materials. A number of agricultural

wastes like, hazelnut shells, orange peels, maize cobs, soyabean hulls, jack fruit, soyabean

hulls in natural or modified forms has been explored and significant removal efficiency was

reported [Kurniawan et al., 2005]. Diverse plant parts such as coconut fiber pith, coconut

shell fibre, plant bark (Acacia arabica, Eucalyptus), pine needles, cactus leaves, neem leave

powder was also tried for Chromium removal showing efficiency more than 90-100% at

optimum pH [Manju and Anirudhan, 1990; Singh et al., 1994; Dakiky et al., 2002; Sarin and

Pant, 2005; Mohan et al., 2006; Venkateswarlu et al., 2007].

Gardea et al. (2000) reported Avena monida (whole plant biomass) showed 90%

removal efficiency at optimum pH 6 in batch studies. Sugarcane bagasse was used in natural

as well as modified form and efficient removal tendency of Cr (VI) was reported [Gupta &

Ali, 2004; Krishanani et al., 2004; Rao and Parwate, 2002]. Garg et al. (2004) tried saw dust

18

of Indian rose wood prepared by treatment with formaldehyde and sulphuric acid for Cr (VI)

removal. The removal efficiency of 86 % was observed for Cr (VI). Farajzadeh et al. (2004)

and Oliveira et al. (2005) reported that rice bran and wheat bran were less effective as an

adsorbent as only 50% removal efficiency was observed.

Acar (2004) and Karthikeyan et al. (2005) reported studies on beech saw dust and

rubber wood sawdust. Beech saw wood showed 100% removal efficiency under optimized

pH conditions where as rubber wood saw dust give 50-60 % of removal efficiency.

Karthikeyan et al. (2005) investigated the adsorption capacity of Cr (VI) on Hevea

Brasilinesis (Rubber wood) sawdust activated carbon in a batch system by considering the

effects of various parameters like contact time, initial concentration, pH and temperature. Cr

(VI) removal was pH dependent and found to be maximum at pH 2. Pseudo second-order

model was found to explain the kinetics of Cr (VI) adsorption. Garg et al. (2007) used

sugarcane bagasse, maize corn cob and jatropha oil cake for the removal of Cr (VI) under

optimized conditions of pH, stirring speed, initial metal ion concentration, contact time and

adsorbent dose. Results showed remarkable potential of selected biosorbents with a removal

efficiency of 85-95 %.

Bhattacharya et al. (2008) studied the potential removal of various materials such as clarified

sludge- a steel industry waste material, rice husk ash, activated alumina, fuller's earth, fly ash,

saw dust and neem bark. The optimum pH range for adsorption of Cr (VI) was found to be

between 2 and 3. For clarified sludge, at pH 3 maximum 97.4% Cr (VI) removal was

observed and for rice husk ash and sawdust efficiency was 94.8% and 86.5%, respectively.

For fly ash and neem bark, the maximum removal of Cr (VI) was achieved at pH 2, and the

removal efficiency was 89.2% and 84.5%, respectively. In other study tamarind (Tamarindus

indica) pod shells were used in the biosorption of Cr (VI) from aqueous solutions. Maximum

removal efficiency was observed at pH 2 by Ahalya (2008). Prasad and Abdullah (2010)

19

reported the biosorption of Cr (VI) from synthetic solutions and electroplating wastewaters

using fruit shells of Gulmohar (Delonix regia). The maximum removal of Cr (VI) was

observed at pH 3 and maximum biosorption capacity was found to be 12.28 mg/g. Overah

(2011) studied the biosorption of Cr (III) on the leaf biomass of Calotropic procera. The

batch experiments showed remarkable and rapid potential of selected biosorbent as

equilibrium was attained within 10 minute of the process at the optimum pH value of 5 with

an adsorption capacity of 32.26.

Idowu et al. (2012) investigated the adsorption of Cr (VI) ion on maize husk biomass from

aqueous solution and the maximum biosorption capacity of the untreated corn shaft biomass

(UTCS) was found to be 28.49 mg/g which slightly increased to 29.33 mg/g with oxalic acid

treated corn shaft biomass (ATCS). Li et al. (2012) prepared food-grade tannic acid-

immobilized powdered activated carbon (TA-PAC), and adsorption of Cr (VI) with metal

concentration of 0.500 mg/L using TA-PAC as a function of pH, contact time, adsorption

capacities and adsorption isotherms at 280 K. The optimal pH value was found to be 4.0 and

equilibrium time was 240 min for TA-PAC. Wei et al. (2012) utilized porous carbon

obtained from pig bone (PC) as the adsorbent for removal of Cr (VI) from aqueous solution.

The effect of solution pH, concentration of Cr (VI) and temperature on the removal of Cr

(VI) was investigated and maximum Cr (VI) adsorption capacity of the PC reported was

398.40 mg/g at pH 2. Gupta et al. (2013) investigated the utilization of sustainable and

biodegradable lignocellulosic biomass extracted from fig plant. The maximum adsorption

capacity of Cr (VI) was found to be 19.68 mg/g. Chemical modification was proposed by

using calcium hydroxide for enhanced removal efficiency. Babarinde et al. (2013) used cocoa

leaf for the removal of Cr (III). The maximum adsorption capacity of the adsorbent was

found 59.35 mg/g for Cr (III) and pseudo second-order kinetic model favored the adsorption

20

process with R2 ≈ 1. Table-2.1 summarizes the work reported in literature for the removal of

Chromium by using agricultural waste materials.

2.2.2 Potential of Agricultural Waste Biomass for Removal of Ni (II)

The major sources of Nickel in the environment are Nickel plating, colored ceramics,

batteries, furnaces used to make alloys or from power plants and trash incinerators. The most

harmful health effect of metal is the allergic reactions [Akhtar et al., 2004].

Agricultural wastes such as pecan, walnut and hazelnut shells in natural or modified form

were also utilized for biosorption [Demirbas et al., 2002; Johns et al., 1998; Kurniawan et al.,

2005; Shukla and Pai, 2004]. Other agricultural waste materials as modified coir fibers,

cotton seeds, soyabeans and corncobs have also been explored for removal of Nickel

[Marshall et al., 1996; Shukla et al., 2005; Vaughan et al., 2001]. Kadervilu (2001, 2003)

studied the utilization of various agricultural wastes for activated carbon preparation and

application for the removal of Hg and Ni metals from aqueous solution. Activated carbon was

prepared from agricultural solid wastes such as silk, cotton hulls, coconut tree sawdust, sago

waste, maize cob and banana pith. Waste tea leaves were tried for the sequestering of Nickel

from aqueous solutions and remarkable results were reported [Ahluwalia and Goyal, 2005].

Sciban et al. (2006) and Shukla et al. (2005) showed saw dust of maple, oak and black locust

as promising biosorbent for removal of Nickel. The adsorption on activated carbon prepared

from apricot stones to remove Ni, Co, Cd, Cu, Pb, Cr ions from aqueous solutions was

investigated by Kobya et al. (2005). Highest adsorption occurred at pH 1-2 for Cr (VI) and at

pH 3-6 for the remaining metal ions. The order of adsorption capacities was Cr (VI) > Cd (II)

> Cu (II) > Cr (III) > Ni (II) > Pb (II) respectively. Namasivayam et al. (2006) used coir pith

to develop ZnCl2 activated carbon and applied to the removal of toxic anions, heavy metals,

organic compounds and dyes from water. Sorption of inorganic anions such as nitrate,

thiocyanate, selenite, and heavy metals such as Nickel (II) and Mercury (II) were investigated

21

and maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L was

achieved.

Hanif (2007) reported studies on the removal of Nickel using Cassia fistula biomass

in its natural form and results show 99-100% removal efficiency. Garg et al. (2007) used

sugar cane bagasse in its natural form showed more than 80% removal efficiency for Ni (II).

Kehinde et al. (2009) utilized coconut husk in its natural form and modified by HCl were

tried for the removal of Ni (II) and HCl modified husk was found more effective with

removal efficiency of 96 % as compared to the natural husk with removal efficiency of 83 %.

Onundi et al. (2010) used granular activated carbon produced from palm kernel shell as

adsorbent to remove copper, Nickel and Lead ions from a synthesized industrial wastewater

at pH 5. A sorption capacity of 1.337 mg/g for Lead, 1.581 mg/g for Copper and 0.130 mg/g

for Nickel was recorded. The percentage metal removal approached equilibrium within 30

min for Lead, 75 min for Copper and Nickel. Aslam et al. (2010) reported the use of Ficus

religiosa (peepal) leaves for the biosorption of Ni (II) in batch systems. The results indicate

that sorption equilibrium was established in about 60 minutes with an equilibrium capacity of

6.35 ± 0.54mg/g. Feng et al. (2011) carried out equilibrium, thermodynamic and kinetic

studies for the biosorption of Pb2+, Cd2+ and Ni2+ ions from aqueous solution using the grafted

copolymerization-modified orange peel (OPAA). The maximum uptake capacities for Pb2+,

Cd2+ and Ni2+ ions were 476.1, 293.3 and 162.6 mg/g, respectively. The kinetics for Pb2+,

Cd2+ and Ni2+ ion biosorption followed the pseudo-second-order kinetics. Kakalanga et al.

(2012) reported the adsorption of Ni (II) ions by employing waste powders prepared from

eggplant (EGP), sweet potato (SWP) and banana peels (BNP). Ni (II) uptake was very fast

reaching a maximum within 20 min of adsorbent contact with metal solution. Comparison of

removal capacities for EGP, SWP and BNP indicated that EGP was more effective in

removing Ni (II) from aqueous solution.

22

Patil et al. (2012) extensively studies on Almond tree (Terminialia cattapa) bark powder

(ATBP), Teak tree (Tectona grandis) bark powder (TTBP), Mangrove plant (Sonneratia

apetala) leaf powder (MPLP), Jackfruit plant (Artocarpus heterophyllus) leaf powder (JPLP),

Cinnamon Plant (Cinnamonum zeylanicum) leaf powder (CPLP) and Chiku (Manikara

zopata ) leaf powder

(CLP). The adsorption capacity of adsorbents towards Ni (II) ions was found to be of the

order of TTBP > CLP > ATBP > MPLP > JPLP > CPLP under optimized conditions.

Bayramoqlu et al. (2012) reported the potential capabilities of Alyssum discolor biomass

collected from serpentine soil and was used for the removal of Ni (II) and Cu (II) metal ions.

The maximum biosorption capacities of the native and acid-treated biomass preparations for

Ni (II) were 13.1 and 34.7 mg/g and for Cu (II) 6.15 and 17.8 mg/g dry biomass, respectively

under optimized conditions of pH, initial metal ion concentration and adsorbent dose.

Mahamadi and Madocha (2013) explored the potential utilization of water hyacinth,

Eichhornia crassipes biomass immobilized in calcium alginate for the removal of Ni (II)

from aquatic solution. Interpretation of sorption data in terms of the separation factor Sf,

suggested the mechanism of chemisorption for removal of Ni (II). Table 2.2 is a compilation

of research work done on the removal of Nickel by using various agricultural waste materials

in their natural forms or with any kind of modification.

2.2.3 Potential of Agricultural Waste Biomass for Removal of Cd (II)

Cadmium and Cadmium compounds as compared to other heavy metals are relatively water

soluble therefore mobile in soil and tends to bioaccumulate. The long lifetime PVC- window

frames, plastics and plating on steel are the basic sources of Cadmium in the environment.

Cadmium accumulates in the human body, especially in the kidneys, thus leading to

dysfunction of the kidney [Volesky and Holan, 1995].

23

Mohan et al. (2002) investigated single and multiple component adsorption of Cd and Zn

using activated carbon derived from bagasse. The removal of Cd (II) and Zn (II) was found to

increase as pH increases beyond 2 and further the sorption affinity of activated carbon was

better for Cd (II) and Zn (II) as compared to many other available biosorbents. Iqbal and

Saeed (2003); Farajzadeh et al. (2004); Montanher et al. (2005); Singh et al. (2005) showed

the potential use of rice bran and wheat bran for sequestering Cadmium and significant

removal efficiency was reported. Studies were also conducted on the use of rice husk and

black gram husk in their natural as well as modified form for the removal of Cd and their

relative efficiency was reported [Tarley et al., (2004); Singh et al., (2005); Kumar and

Bandyopadhyay, (2006)]. Various studies were conducted on activated carbon of bagasse

pith, coir pith and dates and their removal efficiency vary from 50 to 98% [Kadirvelu et al.,

2001; Kannan et al., 2005; Krishnan et al., 2003; Mohan and Singh, 2002; Wafwoy, 1999].

Ajmal et al. (2006) and Seki et al. (1997) used the bark of the plants such as Pecia glehnii

and Abies sachalinensis and dried plant biomass of Parthenium was tried for the efficetive

removal of Cadmium. Benaıssa (2006) reported the use of other parts of the plants such as

peels of peas, fig leaves, broad beans, orange peels, medlar peels and jack fruits as adsorbents

to show high removal efficiency at acidic pH. Johns et al. (1998) and Kurniawan et al. (2006)

conducted adsorption experiments on hazelnut shells, walnut shells, and green coconut shells

and showed significant results for the removal of Cadmium.

Research has been carried out by using chemically treated agricultural waste materials like

base treated rice husk, treated juniper fibers, and corncob modified with citric acid, modified

peanut shells, succinic anhydride treated sugarcane [Karnitz et al., 2007; Min et al., 2004;

Vaughan et al., 2001]. User et al. (2006) investigated the adsorption of the toxic metal ions by

tannic acid immobilized activated carbon depending on pH, contact time, carbon dosage,

adsorption capacity and adsorption isotherms by employing batch adsorption process. In the

24

optimum conditions, the percentage adsorption of metal ions were determined for Cu (II)

(23.5%), Cd (II) (17.8%), Zn (II) (14.0%), Mn (II) (11.3%) and Fe (III) (17.9%) and results

were compared with that of the untreated activated carbon. The adsorption capacity of tannic

acid immobilized activated carbon followed the order of Cu (2.23) > Fe (1.77) > Cd

(1.51) > Zn (1.23) > Mn (1.13) in single systems and Fe (1.56) > Cd (1.48) > Zn (1.19) > Mn

(1.11) in Cu (II) coupled competitive systems.

Saikaew et al. (2009) investigated the ability of pomelo peel, a natural biosorbent, to remove

Cd (II) ions from aqueous solution by biosorption and maximum removal was achieved at pH

5. The equilibrium was attained with a maximum biosorption capacity of 21.83 mg/g within

20 minutes. Dhir and Kumar (2010) performed batch adsorption experiments to study the

adsorption potential of agricultural residues viz. Rice straw, wheat straw and Salvinia plant

biomass for removal of heavy metals such as Cr, Ni, and Cd and Salvinia biomass possessed

higher efficiency for removing Cr, Ni and Cd under optimized condition.

Awwad and Salim, (2011) reported the thermodynamic analysis of a potential biosorbent

loquat (Eriobotrya japonica) leaves waste. Results indicated that the biosorption of Cadmium

ions onto loquat leaves (LL) biosorbent was an endothermic process, resulting in higher

biosorption capacities at higher temperatures. Almasi et al., (2012) explored the biosorption

potential of processed walnut shell for Pb (II) and Cd (II) ions from aqueous solutions. The

maximum adsorption was achieved within the pH range of 4.0–6.0. The maximum monolayer

adsorption capacities were found to be 32g/kg and 11.6g/kg for Pb (II) and Cd (II) ions,

respectively. Ameh (2013) carried out batch adsorption studies to evaluate the adsorption

capacity of Iraqi Palm date for the removal of Cd (II) and Cu (II) ions from synthetic aqueous

solutions. The results indicate the maximum uptake of Cu (II) ions at pH 4.0 and 6.0 for Cd

(II). The adsorption equilibrium data fitted Langmuir model better than Temkin, Dubinin–

Radushkevich and Freundlich models.

25

Dubey et al. (2013) discussed the removal of Cd (II) from aquatic systems by using locally

available Portulaca oleracea plant biomass as an adsorbent. Studies were carried out by

observing critical parameters such as pH, contact time, initial metal ion concentration and

adsorbent dose. The maximum adsorption was found to be 72% in 4 minutes. Summary of

research work done has been compiled in Table-2.3.

2.2.4 Potential of Agricultural Waste Biomass for Removal of Pb (II)

The major source of Lead in the environment is from plastics, finishing tools, cathode

ray tubes, ceramics, solders, pieces of Lead flashing and other minor product, steel and cable

reclamation. Lead can result in the wide range of biological effects depending upon the level

and duration of exposure [Friberg and Elinder, 1985]. In the environment Lead binds strongly

to particles such as oil, sediments and sewage sludge so its removal is of great concern.

Different agricultural wastes viz. rice straw, soybean hulls, sugarcane bagasse and

walnut shells in their natural form have been used for removal of Lead [Johns, 1998]. Lee et

al. (1999) investigated the removal of Lead and other metal ions by apple residues modified

with phosphorous (V) oxychloride in both batch and column studies and compared the

results. The saw dust of maple [Zhang et al., 2001], Pinus sylvestries [Taty-Costodes et al.,

2003] and rubber wood saw dust [Raji et al., 1997] has shown 85-90% removal efficiency but

results show that modification did not enhance the removal efficiency for Lead. Studies

conducted on Febrifuga tree bark in its natural form, petioler felt sheath palm (PFP), agro

waste of black gram husk, flowers of Humulus lupulus, waste tea leaves and water hyacinth

reported removal of Lead and efficiency of these materials varies from 70-98% [Ahluwalia

and Goyal, 2005; Gardea et al., 2002; Iqbal et al., 2002, 2005; Kamble and Patil, 2001; Saeed

et al., 2005]. Removal of Lead from aqueous solutions by coconut-shell carbon was

investigated in batch mode studies by Sekhar et al. (2004). The coconut-shell carbon (CSC)

26

exhibited the highest Lead adsorption capacity of 26.50 mg/g adsorbent at pH 4.5.

Equilibrium data fitted well to the Langmuir, Freundlich, and Temkin isotherm models. Rose

petals pretreated with NaOH, calcium treated sargassum and sugarcane modified with

succinic anhydride has also been utilized for significant removal of Lead [Karnitz et al.,

2007; Nasir, 2007; Tsui et al., 2006].

Activated carbon prepared from agricultural waste was also explored by different workers

and high efficiency for removal of Lead has been reported [Gajghate et al., 1991; Kadirvelu

et al., 2001; Vaughan et al., 2001; Wilson et al., 2006]. Gupta and Mohan et al. (1999) used

bagasse fly ash for removal of Lead with 65% removal efficiency. Chowdhury et al. (2007)

used activated carbon derived from Mangostana garcinia shells for the removal of Pb (II)

metal ions from aqueous solutions. Batch experiments were carried out to study the

equilibrium isotherms, kinetics and thermodynamics. The sorption process was found to be

feasible, endothermic and spontaneously. Imamoglu and Tekir (2008) prepared activated

carbon in their studies from hazelnut husks with zinc chloride activation at 973 K in nitrogen

atmosphere. BET surface area of the activated carbon was found 1092 m2/g and maximum

adsorption capacity for Cu (II) and Pb (II) ions was found to be 6.645 and 13.05 mg/g,

respectively. Geetha et al. (2009) used Areca nut shell, an agricultural solid waste by-product

and was studied for the removal of heavy metals Cr (VI) and Pb (II) from aqueous solution.

An initial pH of 4 was found most favorable for Cr (VI) removal and 5.0 for Pb (II) removal.

Maximum desorption of 88% for Cr (VI) and 91% for Pb (II) were achieved using dilute

hydrochloric acid.

Okoye et al. (2010) produced activated carbon from fluted pumpkin (Telfairia occidentalis)

seed shell and was utilized for the removal of Lead (II) ion from simulated wastewater. The

amount of Lead (II) ion adsorbed at equilibrium from a 200 mg/L solute concentration was

14.286 mg/g. The experimental data conforms very well to the pseudo-second order equation.

27

Anirudhan et al. (2011) studied on activated carbon (AC) derived from waste coconut buttons

(CB) as a suitable adsorbent for the removal of heavy metal ions such as Pb (II), Hg (II) and

Cu (II) from industrial effluents through batch adsorption process. The adsorbent revealed a

good adsorption potential for Pb (II) and Cu (II) at pH 6.0 and for Hg (II) at pH 7. The

adsorption capacities of the AC decreased in the order of Pb (II) > Hg (II) > Cu (II). Alam et

al. (2012) explored the removal of Pb (II) from aqueous solution by chemically pretreated

pomegranate (Punica granatum) biomass. Maximum adsorption capacity for Pb (II) was

observed at pH 4.5. Moyo et al. (2013) used maize tessels as the precursors for making

activated carbon for the adsorption of Pb (II) ions from aquatic systems. The product

obtained was characterized and utilized for the removal of Pb (II) from aqueous solutions

over a wide range of initial metal ion concentration (10–50mg/L), contact time (5–300min),

adsorbent dose (0.1–2.5g), and pH (2–12). The optimum set of conditions for biosorption of

Pb (II) ion was found to be initial concentration 10mg/L, dosage 1.2g, and pH 5.4. Literature

studies revealed that the optimized value for adsorption of Lead is found around pH 5-6. The

work of various researchers has been summarized in table 2.4.

2.2.5 Potential of Agricultural Waste Biomass for Removal of Other Metal

Ions

Various other metal ions such as copper, zinc, arsenic, mercury and cobalt present in various

industrial effluents are of environmental concern due to their toxicity even in low

concentrations. The discharge of these metal ions into the aquatic systems is due to various

human and industrial applications [Masri et al., 1974; Prasad and Dubay, 1995; Mudhoo et

al., 2012].

Variety of agricultural waste viz. Parthenium weed, dry pine needles, bamboo pulp, modified

cotton fibers and saw dust was utilized for the removal of mercury ions [Masri et al., 1974;

28

Rajeshwarisivaraj and Subburam, 2002; Roberts and Rowland, 1973; Shukla and

Sakhardande, 1992]. Vazquiz et al. (1994) reported the sequestering potential of Pinus

pinester bark pretreated with an acidified formaldehyde solution. The influence of

pretreatment conditions and the effect of pH of the solution on the adsorption capacity of the

bark were investigated. Under optimized conditions the removal efficiency was found to be

85-95% for Pb (II), 55-85% for Cu and 51-57% for Zn (II). Marshall and Champagne (1995)

evaluated byproducts of soya bean and cottonseed hull, rice straw and sugarcane bagasse as

metal ion adsorbents in aqueous solutions. The adsorption capacities for Zn metal ions were

varying from 0.52 to 0.06 m eq/g dry weight of byproducts. Munaf et al. (1997) explored the

use of rice husk for removal of toxic metals from waste water. Results reported the %age

removal of Cr (VI), Zn (II), Cu (II) and Cd (II) as 79%, 85%, 80% and 85% respectively

under optimum conditions. Copper impregnated and chemically modified saw dust was also

tried for arsenic removal with significant efficiency [Nag et al., 1998; Raji and Anirudhan,

1998]. Other waste materials like wheat shells and carbonized coir pith has shown high

efficiency for sequestering copper metal [Basci et al., 2003]. Mustard oil cakes and modified

bark of Pinus radiate have also been proven as potential biosorbent [Ajmal et al., 2005; Palma

et al., 2003].

Ajmal et al. (2003) studied the adsorption behavior of Ni (II), Zn (II), Cd (II) and Cr (II) on

untreated and phosphate treated rice husk. Studies revealed the dependence of process on

various parameters such as pH, concentration, contact time, etc. Results reported that the

treated biosorbent enhanced removal efficiency as compared to the natural one. Ajmal et al.

(1998) and Larous et al. (2005) proved significant role of saw dust for removal of copper

metal ions. Rice husk and Water hyacinth along with other low cost adsorbents were studied

for the removal of Arsenic and the efficiency varies between 71-96%. Mohan et al. (2007)

carried out the single and multiple components adsorption of Cd and Zn using activated

29

carbon derived from bagasse and reported the removal of Cd (II) and Zn (II) increases as pH

increases beyond 2. Sorption affinity of activated carbon was better for Cd (II) and Zn (II) as

compared to many other available biosorbents. Amuda et al. (2007) studied the biosorption

process involved in the adsorption of heavy metal-contaminated industrial wastewater using

the coconut shell carbon modified with Chitosan and/or oxidizing agent (phosphoric acid) to

produce composite adsorbent. Operational parameters such as pH, agitation time and

adsorbent concentration, initial ion concentration and particle size were also studied. The

potentially high adsorption efficiency of the adsorbent was reported.

Baccar et al. (2009) explored the use of Tunisian olive-waste cakes as a potential feedstock

for the preparation of activated carbon chemically modified by using phosphoric acid as a

dehydrating agent. To enhance the adsorption capacity KMnO4 modification was done and

the results indicated that Copper uptake capacity was enhanced by a factor of up to 3 for the

permanganate-treated activated carbon. Demirbas et al., (2009) reported the adsorption of Cu

(II) ions from aqueous solutions by hazelnut shell activated carbon (HSAC) in a batch

adsorption system. The adsorption process was relatively fast and equilibrium was

established about 90 min at 6.0 pH. Desorption experiments were carried out and desorption

efficiencies in four cycles were found to be in the range 74–79%.

Bhatti et al. (2011) reported the potential removal of Co and Pb by using red rose waste

biomass under optimized conditions of pH, adsorbent dose, initial metal ion concentration

and stirring speed. Maximum biosorption capacity was found to be 112.0 and 115.9 mg/g for

Pb (II) and Co (II) respectively. Buasri et al. (2012) used rice straw for the removal of Cu (II)

from aquatic Systems. The equilibrium adsorption isotherms showed that biosorbent

possesses high affinity and sorption capacity for Cu (II) ions was 74.70 mg Cu2+ per 1g

biomass. Compiled summary of various researchers has been presented in table 2.5.

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Table 2.1: Summary of Work done by Various Researchers using Low Cost Agricultural Waste Materials for the Removal of Chromium

Agricultural waste Metal Ion Results Reference

Modified bagasse fly ash Cr (VI) 67% Gupta et al., 1999 Oat biomass Cr (III), Cr

(VI) >80% Gardea et al.,

2000 Pretreated bagasse with NaOH and CH3COOH

Cr (VI), Ni (II) 90%, 67% Rao et al., 2002

Formaldehyde treated saw dust Indian rosewood

Cr (VI) 62-86% Garg et al., 2004

Beech saw dust Cr (VI) 100% Acar and Malkoc, 2004

Chemically treated Bagasse Cr (VI) 50-60% Krishanani et al., 2004

Formaldehyde treated rice husk Cr (VI) 88.88% Bishnoi et al., 2004

Bagasse fly ash Cr (VI) 96 – 98% Gupta and Ali, 2004

Wheat bran

Cr (VI) >82% Farajzadeh and Monji, 2004

Eucalyptus bark Cr (VI) Almost 100% Sarin and Pant, 2005

Rubber wood saw dust Cr (VI) 60-70% Karthikeyan et al.,2005

Raw rice bran Cr (VI), Ni (II) 40 – 50% Oliveira et al., 2005

Coconut shell fibers Cr (VI) >80% Mohan et al., 2006 Commercial granular activated carbon (C2 & C3) and AC of waste from sugar industry (C1)

Cr (VI) 93-98% C1>C2>C3

Fahim et al., 2006

Activated carbon from bagasse (carbonization & gasification)

Cr (VI) Significant metal uptake

Valix et al., 2006

Neem leave powder Cr (VI) >96% Venkateswarlu et al., 2007

Sugarcane bagasse, maize corn cob, jatropha oil cake

Cr (III) Upto 97% Garg et al., 2007

Steel sludge, rice husk, activated alumina

Cr (VI) 85-95% Bhattacharya et al., 2008

Tamarindus indica Cr (VI) 80-90% Ahalya et al., 2008

Raw and acid-treated Oedogonium hatei

Cr (VI) 85-95 % Gupta and Ratogi, 2009

Almond green hull Cr (VI) 85-95% Sahranavard et al., 2011

Fig plant biomass Cr (VI) High removal efficiency

Gupta et al., 2013

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Table 2.2: Summary of Work done by Various Researchers using Variety of Agricultural Waste Materials for the Removal of Nickel

Agricultural waste Metal Ion Results Reference Defatted rice bran, chemically treated soybean & cottonseed hulls

Ni (II), Zn (II), Cu (II)

57%, 87% Marshall and Johns, 1996

Hazelnut shell activated carbon

Ni (II) Effective removal

Demirbas et al., 2002

Dye loaded groundnut shells and saw dust

Ni (II), Cu (II), Zn (II)

Up to 90% Shukla and Pai, 2004

Maple saw dust Ni (II) 75% Shukla et al., 2005 Casia fistula biomass Ni (II) 100% Hanif et al., 2007 Tea waste Ni (II) 86% Malkoc and Nuhoglu, 2005 Waste tea leaves Ni (II), Pb (II), Fe

(II), Zn (II) 92%, 84%, 73%

Ahluwalia & Goyal, 2005

Mustard oil cake Ni (II), Cu (II), Zn (II), Cr (II), Mn (II), Cd (II), Pb (II)

Upto 94% Ajmal et al., 2005

Coir fiber chemically modified with hydrogen peroxide

Ni (II), Zn (II), Fe (II)

>70% Shukla et al., 2005

Agro waste of black gram husk

Ni (II), Pb (II), Cd (II), Cu (II), Zn (II)

Upto93% Saeed et al., 2005

Saw dust of oak and black locust hard wood (modified & unmodified)

Ni (II), Cu (II), Zn (II)

70 – 90% Sciban et al., 2006

Sugarcane bagasse Ni (II) >80% Garg et al., 2007 Modified & unmodified Kenaf core, kenaf bast, sugarcane bagasse, coconut coir

Ni (II), Cu (II), Zn (II)

Upto88% Sciban et al., 2007

Ficus religiosa Ni (II) >80 % Aslam et al., 2010 Egg plant, sweet potato Ni (II) >85% Kakalanga et al., 2012 Water hyacinth Ni(II) >80% Mahamadi and Madocha, 2013 Coconut fibre Ni, Cu, Zn Upto 90 % Asiagwu et al., 2013

32

Table 2.3: Summary of Work done by Various Researchers using Variety of Agricultural Waste Materials for the Removal of Cadmium

Agricultural waste

Metal Ion Results Reference

Rice straw, soybean hulls, sugarcane bagasse, peanut shells, pecan and walnut shells

Cd (II), Pb (II), Cu (II), Zn (II), Ni (II)

Pb>Cu>Cd>Zn>Ni

Johns et al., 1998

Rice Bran Cd (II), Cu (II), Pb (II), Zn (II)

>80.0% Ahmed et al., 1998

Sugercane Bagasse Cd (II), Zn (II) 90-95% Mohan and Singh, 2002 Bagasse fly ash Cd (II), Ni (II) 90.0% Gupta, 2003 Steam activated sulphurised carbon (SA-S-C) from bagasse pith

Cd (II) 98.8% Krishnan et al., 2003

Husk of black gram Cd (II) 99% Saeed and Iqbal, 2003 Base treated juniper fiber Cd (II) High removal

capacity Min et al., 2004

Wheat bran Cd (II), Hg (II), Pb (II), Cr (VI), Cu (II), Ni (II)

>82% except Ni

Farajzadeh et al., 2004

Wheat bran Cd (II) 87.15% Singh et al., 2005 Straw, saw dust, datesnut Cd (II) >70% Nagarethinam et al., 2005 Rice polish Cd (II) > 90% Singh et al., 2005 Peels of peas, fig leaves, broad beans, medlar peel

Cd (II) 70-80% Benaıssa, 2005

Hazelnut shell, orange peel, maize cob, peanut hulls, soyabean hulls treated with NaOH & jack fruits

Cd (II), Cr (VI), Cu (II), Ni (II), Zn (II)

High metal adsorption

Kurniawan et al., 2005

Three kinds treated rice husk

Cd (II) 80 - 97% Kumar et al., 2006

Powder of green coconut shell

Cd (II), Cr (II), As (II)

98%

Pino et al., 2006

Dried parthenium powder Cd (II) >99% Ajmal et al., 2006 Bagasse fly ash Cd (II), Ni (II) 65 & 42% Srivastava et al., 2006 Poplar wood saw dust Cd (II), Cu , Zn

(II) Cu>Zn>Cd Sciban et al., 2007

Chemically modified sugarcane with succinic anhydride

Cd (II), Cu (II), Pb (II)

>80% Karnitz Jr. et al., 2007

Pomelo peel Cd (II) 80-90% Saikaew et al., 2009 Rice straw, wheat straw Ni (II), Cd (II) 80-90 % Dhir and Kumar, 2010 Portulaca oleracea Cd (II) 72% Dubey et al., 2013 Iraqi palm date Cd (II), Cu (II) 75-85% Ameh et al., 2013

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Table 2.4: Summary of Work done by Various Researchers using Variety of Agricultural Waste Materials for the Removal of Lead

Agricultural waste Metal Ion Results Reference Febrifuga Bark Pb (II) 100% Bankar and Dara, 1985 Coconut char based activated carbon

Pb (II) 100% Gajghate and Saxena, 1990

Chemical modified apple residue waste

Pb (II) Upto 80% Lee et al., 1998

Chemically modified saw dust of rubber wood

Pb (II) 85% Raji and Anirudhan, 1998

Rice straw, soybean hulls, sugarcane bagasse, peanut shells, pecan and walnut shells

Pb (II), Cu (II), Cd (II), Zn (II), Ni (II)

Pb>Cu>Cd>Zn>Ni

Johns and Marshall, 1998

Low cost sorbents (bark, dead biomass, chitin, sea weed, algae, peat moss, leaf mould, moss, zeolite, modified cotton)

Pb (II), Cd (II), Cr (VI), Hg (II)

Good results Bailey et al., 1999

Water hyacinth Pb (II), Cu (II), Co (II), Zn (II)

70-80% Kamble and Patil, 2001

Activated carbon from coir pith

Pb (II), Hg (II), Cd (II), Ni (II), Cu (II)

Hg-100% Pb- 100% Cu-73% Ni-92% Cd- !00%

Kadirvelu et al., 2001

Agricultural by product Humulus lupulus

Pb (II) 75% Gardea et al., 2002

PFP (petiolar felt sheath palm)- peelings

Pb (II), Cd (II), Cu (II), Zn (II), Ni (II)

>70% Iqbal et al., 2002

Saw dust of Pinus sylvestris

Pb (II), Cd (II) 96 %, 98% Taty-Costodes et al., 2003

Rice Bran Pb (II), Cd (II), Cu (II), Zn (II)

>80.0% Montanher et al., 2004

Agro waste of black gram husk

Pb (II) Upto93% Saeed et al., 2005

Rose biomass pretreated with NaOH

Pb, Zn (II)

75% Nasir, 2006

Oriza sativa husk Pb (II) 98% Zulkali et al., 2006 Hazelnut husk carbon Pb (II) 91% Imamoglu and Tekir, 2008 Activated carbon (fluted pumpkin seed shell)

Pb (II) 85-90% Okoye et al., 2010

Activated carbon (Apricot stone)

Pb (II) 80-90% Mauni et al., 2013

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Table 2.5: Summary of Work done by Various Researchers using Variety of Agricultural Waste Materials for the Removal of Other Metal Ions

Agricultural waste Metal Ion Results Reference Bark of Abies sachalinensis & pecia glehnii

Cd (II), Cu (II), Zn (II), Ag (II), Mn (II)

Upto 63% Seki et al., 1997

Chemically treated charred saw dust

As (III), Cr (VI) 80%, 95% Nag et al., 1998

Copper impregnated sawdust

As (III) >99% Raji et al., 1998

Mango saw dust Cu (II) 60% Ajmal et al., 1998 PFP (petiolar felt sheath palm)- peelings from trunk of palm tree

Ni (II), Pb (II), Cd (II), Cu (II), Zn (II), Cr (VI)

>70% Pb> Cd> Cu> Zn> Ni> Cr

Iqbal et al., 2002

Activated parthenium carbon

Hg (II), Cr (VI), Fe (II)

Significant removal

Rajeshwarisivaraj and Subburam, 2002

Pinus radiata bark Multiple metals >50% Palma et al., 2003

Wheat shell Cu (II) 99% Basci et al., 2004 Papaya wood

Cd (II), Cu (II), Zn (II)

98, 95, 67% Saeed et al., 2005

Hazelnut shell, orange peel, maize cob, peanut hulls, soyabean hulls treated with NaOH & jack fruits

Ni (II), Cr (II), Cu (II), Cd (II), Zn (II)

High metal adsorption

Kurniawan et al., 2005

Rice husk, Chitini, water hyacinth, cellulose sponge, human hair

As (III) 71 – 96% Mohan and Pittman, 2007

Coconut shell carbon Cd (II), Zn (II) High removal Amuda et al., 2007 Tunisian olive cake Cu (II) 90% Baccar et al., 2009 Hazelnut shell activated carbon

Cu (II) 74-79% Damirbas et al., 2009

Red rose waste biomass Co and Pb 85-90% Bhatti et al., 2011