## 4 Applied Strategies for Textile Dye Wastewater Treatment
### Physical Treatment Process
#### 4.1.1 Adsorption  
This approach is an efficient and easy operation applied when the discharge effluent contains a large variety of dyes [56]. An appropriate adsorbent is selected depending on its affinity and ability of regeneration. Adsorbent materials are known to be pricy (e.g., activated carbon), which allowed scientific researchers to find alternative adsorbent materials  
Figure 3: Treatment strategies of textile dyes discharges. such as bentonite clay, fly ash, wheat residue, date stones, nanoparticles, etc., (Figure 3). They are affordable and effective in wastewater treatment [64; 65]. This treatment strategy is achieved through the attachment of the pollutants to the specific surface area of the adsorbent material [66; 67]. The achievement of dyes decolorization by adsorption with activated carbon was extensively studied. For instance, malachite green was adsorbed with curcumin-based activated carbon [65], with tetraethylenepentamine activated carbon [66] and with carbon coated layered double hydroxide [64]. Rhodamine B was successfully adsorbed by ordered mesoporous carbon and commercial activated carbon and by treated rice-husk based activated carbon Acid red 4 adsorption occurred via the activated carbon. Other adsorption methods were applied to remove the Basic fuchsin by bottom ash and deoiled soya and with mussel shell biomass waste and Acid blue 25 with shrimp shells (Table 1). \begin{table}
\begin{tabular}{c c c c} \hline
**Textile Dyes** & **Treatment Methods** & **Type of the Treatment Methods** & **References** \\ \hline \multirow{8}{*}{Malachite green} & Adsorption with curcumin-based activated carbon & & [65] \\ \cline{2-4}  & Adsorption with & Physical & \\  & tetraethylenepentamine & & [66] \\  & functionalized activated carbon & & \\ \cline{2-4}  & _Penicillin olrochlororon_ & & [67] \\ \cline{2-4}  & _Pandornea pulmonicola_ YC32 & & [68] \\ \cline{2-4}  & _Enterobacter asburiae_ XUHX-4 TM & & [69] \\ \cline{2-4}  & _Flavobacterium caeni_ sp. & & [70] \\ \hline \multirow{2}{*}{Crystal violet and malachite green} & Adsorption with carbon-coated & \multirow{2}{*}{Physical} & [64] \\  & layered double hydroxide & & \\ \hline \multirow{8}{*}{Crystal violet} & Surfactant modified & & [71] \\  & magnetic nanoadsorbent & & \\ \cline{2-4}  & Adsorption with & & \\  & bentonite-alginate composite & & \\ \cline{2-4}  & Adsorption onto & & \\ \cline{2-4}  & TLAC/Chitosan composite & & [73] \\ \cline{2-4}  & Ozonation & & [74] \\ \cline{2-4}  & Electrociagulation & & [75] \\ \cline{2-4}  & _Agrobacteriumrium radiobacter_ & & [76] \\ \cline{2-4}  & _Diaporthe scinti_ & & [77] \\ \hline \multirow{4}{*}{Acid yellow} & Adsorption on flakes of chitosan & & [78] \\ \cline{2-4}  & Fenton oxidation & & [79] \\ \cline{2-4}  & Electrocoagulation using & & [80] \\ \cline{1-1}  & iron electrolites & & \\ \hline \multirow{2}{*}{Rhodamine B and Acid yellow} & Adsorption by ordered & \multirow{2}{*}{Physical} & [81] \\ \cline{1-1}  & mesoporous carbon and & & \\ \cline{1-1}  & commercial activated carbon & & \\ \hline \end{tabular}
\end{table} 
Table 1: Examples of textile dyes and their treatment methods.