287
– Sugarcane bagasse pith, reactive orange 3.48 mg/g (activation using 28% H 3 PO 4 ,
50% ZnCl 2 , pyrolysis at 600 °C, physical activation 600 °C without air)
(Amin 2008)
– Rubberwood sawdust (Hevea brasiliensis), bismark brown dye 1456 mg/g
(Kumar et al. 2005)
– Parthenium biomass (sulfuric acid treatment method), rhodamine B 18.52 mg/g
(pH = 7, particle size 0.3–1 mm) (Lata et al. 2008)
– Coir pith (dried in sunlight (5 h), ground; carbonization at 700 °C (1 h) using a
muffle furnace under closed conditions, surface area = 167 m
2
/g, acid brilliant
blue 15.24 mg/g (Kavitha and Namasivayam 2008)
– Rice husk, sawdust, surface area = 272.5–516.3 m
2
/g, acid yellow 36
86.9–183.8 mg/g (Crini 2006)
More examples of commercial activated carbons and activated carbons obtained
from wastes/by-products precursors could be found, e.g., in Crini (2006) and Gupta
and Suhas (2009).
11.4.2 Low-Cost Adsorbents
Natural materials, synthetically prepared materials, as well as industrial or agricultural by-products are included into one group of adsorbents called low-cost adsorbents (Fig. 11.4). As it was mentioned in Sect. 11.4.1. the costs of activated carbons
obtained from wastes (agriculture or industrial wastes) production are much lower
(0.1 USD/kg) compared to the commercial activated carbons (1.5 USD/kg) (Gupta
and Suhas 2009). Similarly, low-cost adsorbents are cheaper alternatives; therefore
they can be substitutes for all expensive adsorbents applied for treatment of wastewaters containing dyes. Moreover, they give double benefits such as waste management and treatment (Yagub et al. 2014).
Application of agricultural solid wastes for dyes sorption is an environmentally
friendly, economical, and efficient process (Afroze and Sen 2018). Forest industries
produce a large amount of solid wastes such as sawdust, bark, and shavings
(Fig. 11.7) which due to their physicochemical properties are potential materials
capable to effective removal of dyes (Ho and McKay 1998a; McKay et al. 1999;
Özacar and Sengil 2005; Shukla et al. 2002; Velić et al. 2018). Such materials contain organic compounds with the polyphenolic groups (cellulose, hemicellulose,
lignin) useful for dyes binding or possess a large tannin content (e.g. bark) which
enhances dyes removal. Low cost of waste wood materials (transport influences
largely their total cost) and broad availability make waste wood materials very
promising as adsorbents. Moreover, the sorption results obtained using the wood
sawdust depend largely on pH (Garg et al. 2003; Ho and McKay 1998a) and initial
concentration of adsorbate (Khattri and Singh 2000). Ho and McKay (1998a)
pointed out that the sorption capacity due to the ionic character of sawdust is much
higher for basic than for acidic dyes. Raw sawdust usually exhibits lower sorption
11 Characteristics and Adsorptive Treatment of Wastewaters Containing Dyes
– Sugarcane bagasse pith, reactive orange 3.48 mg/g (activation using 28% H 3 PO 4 ,
50% ZnCl 2 , pyrolysis at 600 °C, physical activation 600 °C without air)
(Amin 2008)
– Rubberwood sawdust (Hevea brasiliensis), bismark brown dye 1456 mg/g
(Kumar et al. 2005)
– Parthenium biomass (sulfuric acid treatment method), rhodamine B 18.52 mg/g
(pH = 7, particle size 0.3–1 mm) (Lata et al. 2008)
– Coir pith (dried in sunlight (5 h), ground; carbonization at 700 °C (1 h) using a
muffle furnace under closed conditions, surface area = 167 m
2
/g, acid brilliant
blue 15.24 mg/g (Kavitha and Namasivayam 2008)
– Rice husk, sawdust, surface area = 272.5–516.3 m
2
/g, acid yellow 36
86.9–183.8 mg/g (Crini 2006)
More examples of commercial activated carbons and activated carbons obtained
from wastes/by-products precursors could be found, e.g., in Crini (2006) and Gupta
and Suhas (2009).
11.4.2 Low-Cost Adsorbents
Natural materials, synthetically prepared materials, as well as industrial or agricultural by-products are included into one group of adsorbents called low-cost adsorbents (Fig. 11.4). As it was mentioned in Sect. 11.4.1. the costs of activated carbons
obtained from wastes (agriculture or industrial wastes) production are much lower
(0.1 USD/kg) compared to the commercial activated carbons (1.5 USD/kg) (Gupta
and Suhas 2009). Similarly, low-cost adsorbents are cheaper alternatives; therefore
they can be substitutes for all expensive adsorbents applied for treatment of wastewaters containing dyes. Moreover, they give double benefits such as waste management and treatment (Yagub et al. 2014).
Application of agricultural solid wastes for dyes sorption is an environmentally
friendly, economical, and efficient process (Afroze and Sen 2018). Forest industries
produce a large amount of solid wastes such as sawdust, bark, and shavings
(Fig. 11.7) which due to their physicochemical properties are potential materials
capable to effective removal of dyes (Ho and McKay 1998a; McKay et al. 1999;
Özacar and Sengil 2005; Shukla et al. 2002; Velić et al. 2018). Such materials contain organic compounds with the polyphenolic groups (cellulose, hemicellulose,
lignin) useful for dyes binding or possess a large tannin content (e.g. bark) which
enhances dyes removal. Low cost of waste wood materials (transport influences
largely their total cost) and broad availability make waste wood materials very
promising as adsorbents. Moreover, the sorption results obtained using the wood
sawdust depend largely on pH (Garg et al. 2003; Ho and McKay 1998a) and initial
concentration of adsorbate (Khattri and Singh 2000). Ho and McKay (1998a)
pointed out that the sorption capacity due to the ionic character of sawdust is much
higher for basic than for acidic dyes. Raw sawdust usually exhibits lower sorption
11 Characteristics and Adsorptive Treatment of Wastewaters Containing Dyes