contains silver nanoparticles which assist in removal of pesticides from water. The
removal of pesticide, namely atrazine after treatment of silver nanoparticle composite bioadsorbent present in the chitosan has been reported. The pesticide content
noted a sharp decline in water when the adsorbent dose was increased from 0.5 to
2.0 g. Cross-linked chitosan-silver nanoparticles composite microbeads showed
adsorption capacity of 115 μg mL
À1 (Saifuddin et al. 2011).
Removal of compounds like hexachlorobenzene and chlorinated hydrocarbons
has been reported after treatment with bimetallic nanoparticles, viz. Ag/Fe, Ni/Fe,
Cu/Fe (Yan et al. 2010; Koutsospyros et al. 2012; Nie et al. 2013). Bimetallic
coreshell Fe/Ni and Fe/Pd nanoparticles showed capacity to dechlorinate toxic
chlorinated organic compounds (Xu and Bhattacharyya 2005). Gold nanospheres
and nanorods have shown capacity for adsorption of organophosphorus pesticides
such as dimethoate. Adsorption of nanospheres resulted in aggregation (Momić et al.
2016). Nanospheres and nanorods have shown adsorption capacity of 456 mg g
À1
for 57.1 mg g
À1 , respectively. These nanoparticles have been used successfully for
removing dimethoate from drinking water.
Carbon nanotubes (CNTs) composed of graphitic carbons have shown great
capacity to remove pesticides (Pyrzynska 2011). Pore structure and surface functional groups present in CNTs help in the adsorption of pollutants. The mechanisms
such as hydrophobic effect, covalent bonding, π–π interactions, hydrogen bonding,
and electrostatic interactions help in adsorption of organic chemicals on CNTs.
Transformation of organic compounds such as pesticides, pharmaceuticals, and
drugs present in wastewater has been reported using single walled (SWNTs) or
multiwalled CNTs (MWCNTs) (Deng et al. 2012; Yu et al. 2014). These nanotubes
have also been found effective in removing volatile organic compounds and dioxins
(Li et al. 2003; Long and Yang 2005; Peng et al. 2005; Rao et al. 2007). Polar
aromatic compounds and polycyclic aromatic hydrocarbons (PAHs) get adsorbed on
CNT through π–π interaction. Adsorption of compounds has been achieved when
hydrogen bonding occurs between functional groups such as -COOH, -OH, -NH 2 ,
and organic molecules. The wet ability of CNTs surfaces get altered with functional
groups. These groups make them more hydrophilic and suitable for sorption of low
molecular weight and polar compounds (Shi et al. 2010). Both SWCNTs and
MWCNTs possess thermal stability and specific chemical properties (Cho et al.
2008). The removal of compounds such as diuron and dichlobenil via adsorption on
MWNTs has been noted. Adsorption of compounds gets increased with an enhancement in the surface area and total pore volume of MWNTs. Adsorption of atrazine by
SWNTs and MWNTs has been reported. Multiwalled carbon nanotube (MWNT),
nano-clay, and nano-alumina have shown capacity for adsorbing
dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs).
MWNT proved to be good adsorbent material for both contaminants. Removal of
88.9% and 77% for DDT and PCB at 10% of MWNT has been reported (Taha and
Mobasser 2015).
Unique physical and chemical properties of graphene, a carbon nanomaterial
contributed to its capacity to remove pesticides (Maliyekkal et al. 2012; Nodeh et al.
2019). The pesticides removal by graphene occurs mainly via adsorption (ranging
196
B. Dhir
removal of pesticide, namely atrazine after treatment of silver nanoparticle composite bioadsorbent present in the chitosan has been reported. The pesticide content
noted a sharp decline in water when the adsorbent dose was increased from 0.5 to
2.0 g. Cross-linked chitosan-silver nanoparticles composite microbeads showed
adsorption capacity of 115 μg mL
À1 (Saifuddin et al. 2011).
Removal of compounds like hexachlorobenzene and chlorinated hydrocarbons
has been reported after treatment with bimetallic nanoparticles, viz. Ag/Fe, Ni/Fe,
Cu/Fe (Yan et al. 2010; Koutsospyros et al. 2012; Nie et al. 2013). Bimetallic
coreshell Fe/Ni and Fe/Pd nanoparticles showed capacity to dechlorinate toxic
chlorinated organic compounds (Xu and Bhattacharyya 2005). Gold nanospheres
and nanorods have shown capacity for adsorption of organophosphorus pesticides
such as dimethoate. Adsorption of nanospheres resulted in aggregation (Momić et al.
2016). Nanospheres and nanorods have shown adsorption capacity of 456 mg g
À1
for 57.1 mg g
À1 , respectively. These nanoparticles have been used successfully for
removing dimethoate from drinking water.
Carbon nanotubes (CNTs) composed of graphitic carbons have shown great
capacity to remove pesticides (Pyrzynska 2011). Pore structure and surface functional groups present in CNTs help in the adsorption of pollutants. The mechanisms
such as hydrophobic effect, covalent bonding, π–π interactions, hydrogen bonding,
and electrostatic interactions help in adsorption of organic chemicals on CNTs.
Transformation of organic compounds such as pesticides, pharmaceuticals, and
drugs present in wastewater has been reported using single walled (SWNTs) or
multiwalled CNTs (MWCNTs) (Deng et al. 2012; Yu et al. 2014). These nanotubes
have also been found effective in removing volatile organic compounds and dioxins
(Li et al. 2003; Long and Yang 2005; Peng et al. 2005; Rao et al. 2007). Polar
aromatic compounds and polycyclic aromatic hydrocarbons (PAHs) get adsorbed on
CNT through π–π interaction. Adsorption of compounds has been achieved when
hydrogen bonding occurs between functional groups such as -COOH, -OH, -NH 2 ,
and organic molecules. The wet ability of CNTs surfaces get altered with functional
groups. These groups make them more hydrophilic and suitable for sorption of low
molecular weight and polar compounds (Shi et al. 2010). Both SWCNTs and
MWCNTs possess thermal stability and specific chemical properties (Cho et al.
2008). The removal of compounds such as diuron and dichlobenil via adsorption on
MWNTs has been noted. Adsorption of compounds gets increased with an enhancement in the surface area and total pore volume of MWNTs. Adsorption of atrazine by
SWNTs and MWNTs has been reported. Multiwalled carbon nanotube (MWNT),
nano-clay, and nano-alumina have shown capacity for adsorbing
dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs).
MWNT proved to be good adsorbent material for both contaminants. Removal of
88.9% and 77% for DDT and PCB at 10% of MWNT has been reported (Taha and
Mobasser 2015).
Unique physical and chemical properties of graphene, a carbon nanomaterial
contributed to its capacity to remove pesticides (Maliyekkal et al. 2012; Nodeh et al.
2019). The pesticides removal by graphene occurs mainly via adsorption (ranging
196
B. Dhir