**4. Type of nanomaterials in wastewater treatment**

A substantial amount of study has been conducted on the use of nanotechnology for wastewater treatment. Based on the materials used, nanotechnology may be divided into three categories: Nanoadsorbents, nanocatalysts, and nanomembranes present in **Table 1** and **Figure 1**.

### **4.1 Nano-adsorbents**

Adsorbent nanoparticles are nanoparticles composed of organic or inorganic materials with a high affinity for adsorbing chemicals. This implies they can remove a large amount of pollution. Because of their key qualities, such as catalytic potential, small size, high reactivity, and increased surface energy, these nanoparticles may be used to remove many types of contaminants. Metallic nanoparticles, mixed oxide nanostructures, magnetic nanoparticles, and metal oxide nanoparticles all have distinct adsorption mechanisms. Example is Zeolites comprise aluminosilicate minerals having a surface morphology filled with electrostatic pores populated by cations and water molecules. Cations and water molecules have a wide range of movement options, allowing for ion exchange and reversible dehydration. CNTs feature a large surface area, a large number of adsorption sites, and variable surface chemistry as shown in **Table 1**.


*Sewage Treatment Using Nanoparticles DOI: http://dx.doi.org/10.5772/intechopen.109407*


#### **Table 1.**

*Varied instances of the use of nanocarriers in the treatment of wastewater.*

#### **Figure 1.**

*Schematic explanation of the method of action followed by different types of nanoformulations used in wastewater treatment currently.*

#### **4.2 Nano-catalyst**

Light energy interacts with metallic nanoparticles in nano-catalysis, resulting in high and broad photocatalytic activity. Because of its great and broad photocatalytic activity, this therapy is gaining favor. Bacteria and enzymes participate

in a photocatalytic reaction. Manganese Ferrous Oxides, Silica Oxides and Silver (MnFe2O4-SiO2-Ag) act as catalyst and its mode of action shown in **Table 1**.

#### **4.3 Nano-membrane**

The separation of particles from wastewater is the responsibility of a nanomembrane. These filters are extremely good in filtering out dyes, heavy metals, and other contaminants. Nanomaterials utilized as nano-membranes include nanotubes, nanoribbons, and nanofibers.

Nanoparticles integrated into membranes are more convenient and beneficial than nano-adsorbents, nano-catalysts, and nano-membranes because this procedure not only has a powerful physical treatment, but it also contains nanoparticles to increase the quality of the treatment.

To inhibit bacterial development, several eco-friendly nanostructured lipid carriers (NLCs) were created as delivery agents to appropriately carry an antibacterial agent (eugenol) into hospital wastewater. Hot high-speed homogenization was used to create eugenol-loaded nanostructured lipid carriers. The nanocarriers were then analyzed using several methods including transmission electron microscopy, Fourier transforms infrared and dynamic scanning calorimetry. The ability of the produced eugenol-loaded nanostructured lipid carriers to reduce the bacterial growth rate in culture media and hospital wastewater was determined using the turbidity test and colony counting technique, respectively. NLC-mean eugenol's size and zeta potentials were 78.12 6.1 nm and 29.43 2.21 mV, respectively. The maximum inhibitory impact of NLC-eugenol in culture medium was reported in standard and wild *Staphylococcus aureus* strains (43.42% and 26.41%, respectively) at 0.125 M concentration. The antibacterial activity of NLC-eugenol in sterile wastewater on wild bacteria strains revealed that 0.125 M was the most effective concentration to reduce bacterial quantities on wild *S. aureus* and *Enterococcus faecalis* strains (38% and 33.47%, respectively) at 37°C. At 25°C, NLC-eugenol at 0.125 M had the best impact, lowering total microbiological agents by 28.66% in hospital wastewater as shown in **Table 1** [57].
