1. Dopamine-modified Graphene-based Adsorbent for Antibiotics Removal from Aqueous Solutions
Yuting Lin, Yan Zhang, Marcia Silva
Water Technology Accelerator (WaTA)

2. Method Figure 1 The polymerization process of dopamine
Tetracycline (TC)
Ciprofloxacin (CIP)
Figure 1 The polymerization process of dopamine
Figure 2 The target antibiotics
Dopamine: for Graphene-based materials reduction
SiO2 & Al2O3 (natural porous materials)
PDA: for adhesion
Figure 3 The dopamine-modified graphene-based adsorbent

3. Characteristics Scanning Electron Microscope (SEM) Raman Spectroscopy
Surface
Figure 4 The SEM images of adsorbent
Raman Spectroscopy
Figure 5 The Raman image for adsorbent
ID/IG=1.15

4. Results Model Compound Kinetic Model Compound Isotherms
The pseudo-second-order model
Kinetic study of organic model compound, MB, fit the pseudo- second order model: 𝑡 𝑞 𝑡 = 1 𝑘 2 ∙ 𝑞 𝑒 𝑞 𝑒 𝑡; 𝑞 𝑒 = 1 slope ; 𝑘 2 = slope 2 intercept . 𝑞 𝑒 : Measured values of equilibrium adsorbate concentration in solid phase (mg g-1), 𝑞 𝑡 : Amount of dye absorbed (mg g-1) at time t, t: time (hrs).
Isotherms study of organic model compound was studied with different initial compounds concentration, temperature, pH and NaCl ion concentration
Figure 7 organic model compound (Methyl Blue, MB) Kinetic for adsorbent
Model Compound Isotherms
Figure 8 organic model compound (Methyl Blue, MB) Isotherms for adsorbent

5. Figure 9 The adsorption behavior of CIP
Results
CIP Adsorption
CIP adsorption behavior was studied with contact time and initial compound concentration. TC was also tested but with limited adsorption (~0).
Figure 9 The adsorption behavior of CIP

6. Conclusion
The dopamine reduced graphene-based materials was successfully reduced and tightly coated on the surface of porous materials.
The Kinetic study for modified adsorbent with MB fits the pseudo-second order model.
The isotherms study for modified adsorbent with MB shows the adsorption behavior to equilibrium under different initial concentration, temperature, pH and NaCl concentration.
The modified adsorbent’s adsorption behavior of CIP and TC shows the selectivity adsorption properties.

7. Reference https://pubs.acs.org/doi/10.1021/ma101526k