3.2.3. MNPs for the removal of anionic dyes

Long et al. [50] synthesized Fe3O4@catechol/polyethylenimine (PEI) nanoparticles and tested for adsorption of three different kind of anionic dyes, i.e., methyl blue, orange G and amaranth and found the maximum adsorption capacities of 344.8, 192.3 and 146.2 mg/g, respectively. Saksornchai et al. [51] synthesized magnetite (Fe3O4) coated with cetyltrimethylammonium bromide (CTAB) and tested for the adsorption of anionic dye Congo red (CR) removal. They found maximum adsorption capacity for CR dye to be 93.46 mg/g. Faraji et al. [52] synthesized triazine-based nitrogen-rich network-modified magnetic nanoparticles were synthesized for the adsorption of methyl orange. Sahraei et al. [53] reported the synthesis of magnetic bio-sorbent hydrogel beads based on modified gum tragacanth/graphene oxide for the removal of heavy metals and dyes from water. They found the adsorption capacity of 101.7 mg/g for Congo red dye. Ge et al. [54] fabricated Fe@MgO magnetic nanocomposites for the removal of heavy metal ions and dye from water. They found that the synthesized nanocomposite showed excellent adsorption capacity of 6947.9 mg/g for methylene orange. Wu et al. [55] fabricated multifunctional magnetic nanoparticle core covered with polyethylenimine (PEI) derived quaternary ammonium compounds (QAC) corona through electrostatic attraction for the removal of dyes and metal ion adsorption. The adsorption results corresponding to synthesized nanoparticle showed the maximum adsorption capacity of 653 mg/g for AF as a representative of dyes. Konicki et al. [56] synthesized Fe@graphite core shell nanocomposite for the removal of anionic dyes from aqueous solution. The synthesized nanoparticles were tested for the adsorption of two anionic dyes namely acid red 88 (AR88) and direct orange 26 (DO26) and the maximum adsorption capacity was found to be 63.7 mg/g and 42.7 for AR88 and DO26, respectively. Zhang et al. [57] synthesized the Fe3O4 nanoparticle modified with 3-glycidoxypropyltrimethoxysilane (GPTMS) and poly-lysine (P-Lys). They found that the synthesized MNPs could effectively remove anionic dyes including methyl blue (MB), orange I (OR-I), amaranth (AM) and acid red 18 (AR-18) from water solution.

#### 3.2.4. MNPs for the removal of cationic dyes

Cationic dyes are most toxic because they can easily interact with negatively charged cell membrane surfaces, and also they can enter in to the cells and can concentrate in cytoplasm (Bayramoglu et al.) [58]. Ge et al. [59] have studied the adsorption of cationic dyes such as crystal violet, methylene blue and alkali blue 6B from aqueous solutions by use of polymermodified magnetic nanoparticles. The cationic dyes could be quickly removed from water solution with high efficiency at pH 5–12. More significantly, the MNP showed high efficiency as a reusable adsorbent for fast and convenient removal of cationic dyes from water solution. Yan et al. [60] have synthesized full biodegradable magnetic adsorbent based on glutamic acid modified chitosan and silica coated Fe3O4 nanoparticles for removal of three different kinds of cationic dyes, methylene blue, crystal violet and cationic light yellow 7GL, from aqueous solutions. Chen et al. [61] have prepared magnetic adsorbent by fabrication of chitosan/ polyacrylic acid multilayer onto magnetic Fe3O4 microspheres for removal of adsorption of two cationic dyes, methylene blue and crystal violet from aqueous solution. Amiri et al. [62] synthesized cobalt ferrite silica magnetic nanocomposite for the adsorption of Malachite green dye and found the adsorption capacity of 75.5 mg/g for that dye. Li et al. [63] synthesized wettable magnetic hypercrosslinked microporous nanoparticle for the water treatment. The synthesized nanoparticle consists of microporous organic polymer which combine sodium acrylate functionalized hypercrosslinked polymer with magnetic Fe3O4 nanoparticle to form a hybrid. They tested the synthesized hybrid for the adsorption of Rhodamine B dye and found the maximum adsorption capacity of 216 mg/g. Singh et al. [64] had synthesized the superparamagnetic nanoparticles coated with green tea polyphenol by wet chemical method. They found that the particles have a very high adsorption capacity of (7.25 mg/g) for removal of methylene blue (MB) dye in wastewater treatment. Li et al. [65] synthesized magnetic peach gum bead bio-sorbent for the adsorption of MB dye and found the maximum adsorption capacity of 231.5 mg/g.

Liu [70] discussed the use of various magnetic nanoparticles (MNPs) in pharmaceutical

Xu et al. [82] demonstrated that poly-allylamine-hydrochloride (PAAH) stabilized magnetic nanoparticles are powerful tools to remove pathogenic bacteria from drinking water with high efficiency and no significant toxicity was observed in the MNPs treated water. Over 99.5% of the pathogens (four main pathogens viz. Escherichia, Acinetobacter, Pseudomonas and Bacillus)

Zhang et al. [83] synthesized magnetic nanoparticle coated with Cu doped MgO through a hydrophilic carbon layer (Fe3O4@C@MgO-Cu). They found its potential application as disinfectant in water purification by examining the antibacterial activity of the Fe3O4@C@MgO-Cu composite toward Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus.

lene)]bisacrylamide) (POHABA)-based core-shell nanostructure on the Fe3O4 core surface (Fe3O4@POHABA). The magnetic nanocomposite, Fe3O4@POHABA can be used in domestic

Rana et al. [85] synthesized ferromagnetic Ni-doped ZnO nanoparticles and applied as an antibacterial agent to control the growth of bacterial pathogens. They found the as synthesized

material to be very effective against water related bacteria such as E. coli and V. cholera.

Zero valent iron (ZVI) Carbamazepine Chemical degradation [73]

Atenolol, gemfibrozil, and sulfamethoxazole

MnFe2O4/(activated carbon)AC Sulfamethoxazole Adsorption [77] MgFe2O4/γ-Fe2O3 Minocycline Adsorption [78]

Fe3O4@α-MnO2 microspheres Ciprofloxacin Catalytic degradation [80] Fe-ZnO Diclofenac Photocatalytic degradation [81]

and chlortetracycline


Study on Magnetic Materials for Removal of Water Pollutants

http://dx.doi.org/10.5772/intechopen.75700

69

Processes involved for decontamination

Amoxicillin, ampicillin Adsorption [72]

Diazepam Chemical degradation [74]

degradation (Fenton oxidation)

Adsorption [75]

Adsorbent [76]

Sono-degradation [79]

References

[71]

removal from waste water their recent review which are outlined below (Table 2).

can be removed when the bacterial count was less than 105 CFU/mL.

Zhang et al. [84] synthesized magnetic poly-N,N<sup>0</sup>

Magnetic materials used Pharmaceuticals present in

MFe2O4 (M = Fe, Mn, Co, Zn) Tetracycline, oxytetracycline,

Table 2. Magnetic nanomaterials used for removal of pharmaceuticals.

water

Nano zero-valent iron (nZVI) Carbamazepine Adsorption, chemical

water treatment against bacterial pathogens.

Nano zero-valent iron (nZVI) and PEG

Maghemite (Fe2O3) core confined in a

Fe3O4 MNPs in ultrasound (US)/H2O2

and zeolite supported nZVI

silica porous layer

system

3.2.6. MNPs for removal of pathogens

#### 3.2.5. MNPs for the removal of pharmaceutical products

The presence of pharmaceuticals such as antibiotics, anticonvulsants, antipyretics drugs, hormones in surface and ground water possesses a major environmental challenge. Their contamination even at trace amount is a serious concern to the aquatic organisms as well.

Attia et al. [66] synthesized magnetic nanoparticles coated zeolite for the adsorption of pharmaceutical compounds from aqueous solution. They found that the synthesized magnetic nanoparticles can remove more that 95% of PPCPs in 10 min. Reddy et al. [67] reviewed spinal ferrite nanoparticles and found that SF and its derivatives can be used for remediation of various pollutants. Nadim et al. [68] Synthesized gallic acid coated magnetic nanoparticles (GA-MNP) and used as a photocatalyst for degradation of meloxicam; a commonly prescribed nonsteroidal anti-inflammatory drug.

Recently, M. Hayasi and his coworker described the use of magnetic poly (styrene-2-acrylamido-2-methyl propanesulfonic acid) (St-AMPS) as adsorbent for removal of the pharmaceuticals viz. ceftriaxone sodium, diclofenac sodium, and atenolol from water [69].

Liu [70] discussed the use of various magnetic nanoparticles (MNPs) in pharmaceutical removal from waste water their recent review which are outlined below (Table 2).
