Factors influencing antibiotics adsorption onto engineered adsorbents.
The study evaluated the adsorption of two antibiotics by four engineered adsorbents (hypercrosslinked resin MN-202, macroporous resin XAD-4, activated carbon F-400, and multi-walled carbon nanotubes (MWCNT)) from aqueous solutions. The dynamic results demonstrated the dominant influence of pore size in adsorption. The adsorption amounts of antibiotics on XAD-4 were attributed to the hydrophobic effect, whereas steric hindrance or micropore-filling played a main role in the adsorption of antibiotics by F-400 because of its high microporosity. Aside from F-400, similar patterns of pH-dependent adsorption were observed, implying the importance of antibiotic molecular forms to the adsorption process for adsorbents. Increasing the ionic concentration with CaC12 produced particular adsorption characteristics on MWCNT at pH 2.0 and F-400 at pH 8.0, which were attributed to the highly available contact surfaces and molecular sieving, respectively. Its hybrid characteristics incorporating a considerable portion of mesopores and micropores made hypercross linked MN-202 a superior antibiotic adsorbent with high adsorption capacity. Furthermore, the adsorption capacity of MWCNT on the basis of surface area was more advantageous than that of the other adsorbents because MWCNT has a much more compact molecular arrangement.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210093, China. mingfang_xia@sina.com
Mingfang
M
Xia
Aimin
A
Li
Zhaolian
Z
Zhu
Qin
Q
Zhou
Weiben
W
Yang
D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007475:Ion Exchange Resins; D037742:Nanotubes, Carbon / Q000737:chemistry; D009994:Osmolar Concentration; D011137:Polystyrenes / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry; D013412:Sulfadimethoxine / Q000737:chemistry*; D013427:Sulfapyridine / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D007475:Ion Exchange Resins; D037742:Nanotubes, Carbon; D011137:Polystyrenes; D011145:Polyvinyls; D014874:Water Pollutants, Chemical; D013412:Sulfadimethoxine; C012101:XAD-4 resin; D013427:Sulfapyridine