# Wastewater Treatment by Polymeric Microspheres: A Review
## 2 Synthetic Polymer
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**S. No** & **Polymer** & **Adsorbate** & **Results** & **Kinetic Model** & **Isotherm Model** & **Reference** \\ \hline
1 & Sodium silicate & Pb(II) & 629.21 mg/g & PSO & Langmuir, D-R & [24] \\ \hline
2 & HGM@MPD-ALS & AG25, BF dyes & & 454.55 mg/g, 588.24 mg/g & PSO & Langmuir & [25] \\ \hline
3 & \(\beta\)-CD-GO aerogel & MB, RhB, AR87, MO dyes, 2,4-DCP, PRO, EO, 48 PA & 439, 388, 234, 167, 17, 49, 19, 38 mg/g & - & - & [26] \\ \hline
4 & CG/KGP & MB dye & 24.6 mg/g & PSO & Langmuir & [27] \\ \hline
5 & PMMA@Fe\({}_{3}\)O\({}_{4}\)@DR & RhB, ST dye & 99\%, 98\% & & & [28] \\ \hline
6 & PAM & MB, NR, GV dye & 1990, 1937, 1850 mg/g & & Langmuir & [29] \\ \hline
7 & MF resin & PFOA & 1.18 mM/g & PSO &
\begin{tabular}{c} Freundlich, \\ Langmuir \\ \end{tabular} & [30] \\ \hline
8 & Poly[ANE + \\  & N-PMI]-TiO\({}_{2}\) & RhB, TC dye & 95\% for 50 mg/L RbB, 97\% for 100 mg/L TC & PFOO & L-H & [31] \\ \hline
9 & SiO\({}_{2}\)/PANI/BiOBr & Oil-water emulsion separation & TOC content \textless{} 5 mg/L & - & [32] \\ \hline
1 & PSO: pseudo-second-order, D-R: Dubinin–Radushkevich, HGM: hollow glass microsphere, MPD: m-phenylenediamine, ALS: sodium allyl sulfonate, AG25: acid green 25, BF: basic fuchsin, \(\beta\)-CD: \(\beta\)-cyclodextrintrin, GO: graphene oxide, MB: methylene blue, RhB: rhodamine B, AR87: acid red 87, MO: methyl orange, 2,4-DCP: 2,4-dichlorophenol, PRO: propranolol hydrochloride, EO: contraceptive ethyl) estradiol, BPA: bisphenol A, CG: coal gauge, KGP: geopolymer, PMMA: poly(methyl methacrylate), DR: diazo-resin, ST: safrann T, PAM: polyacrylamide, MF: melamine formaldehyde, NR: neutral red, GV: gentian violet, PRO: perfluoroconate acid, ANE: trans-anethole, N-PMI: N-Phenylmaleimide, TC: tetracycline, PFO: pseudo-first-order, L-H: Langmuir-Hinshelwood, PANI: polyaniline, TOC: total organic carbon. & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary efficiency of polymer as adsorbent. -arcinogenic 2,4-dichlorophenol, 49 mg/g for propranolol hydrochloride, 19 mg/g for contraceptive ethylryl estradiol, and 38 mg/g for plastic components bisphenol A. Most pollutants reached equilibrium within 10 min, and the CD-GAM microsphere maintained its adsorption capacity over 80% during five cycles. In order to check the role of carbon material, a porous coal gangue microsphere/geopolymer (CG/KGP) composite was made for filtrating wastewater and adsorption treatment of dye [27]. It was synthesized by adding coal gangue microspheres into geopolymer matrix. CG/KGP composites mainly contain amorphous phases, and functional groups are mainly on the particle surface. XRD patterns confirmed that when the CG/KGP composite was pre-calcined below 1000 \({}^{\circ}\)C, the CG microspheres are consisted of kaolinite and \(\alpha\)-quartz phases, homogeneously dispersed, and bonded well with pure KGP. Incorporation of CG microspheres, especially CG800 and CG900, greatly enhanced the adsorption capacity and BET surface area. The CG900/KGP samples showed 24.6 mg/g adsorption capacity and the removal efficiency achieved 98% at the dosage of 4 g/L. The adsorption of MB followed the PSO kinetic model and the Langmuir model. The maximum adsorption capacity of CG/KGP particles reached around 10 mg/g. A polymer coated magnetic nanoparticle, PMMA@Fe\({}_{3}\)O\({}_{4}\)@DR composite, was prepared for simple and quick dye adsorption from wastewater [28]. First, a PMMA (poly-methylmethacrylate) porous microsphere was synthesized via the seed swelling method. Then, iron oxide nanoparticles were formed in situ within the pore of the microsphere. Finally, the porous magnetic microspheres were encapsulated with photosensitive diazo-resin (DR) to increase the stability of the magnetic material. The magnetic measurements were measured using an alternate gradient magnetometer. The magnetization was 4.85 emu/g in magnetic field of \(-\)4.5 to 4.5 kOe at room temperature.