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The adsorption behaviors of chlortetracycline on two kinds of granular activated carbons with different BET surface area and average pore width have been studied. The results show that larger BET surface area is beneficial for the adsorption capacity, and wider pore structure can enhance the adsorption rate. Initial solution pH has great effect on the adsorption behavior, and the suitable pH for the effective adsorption is from 4 to 8.

A novel magnetic weak acid resin NDMC-1 was prepared in the presence of methyl acrylate (MA), divinylbenzene (DVB) and titanate coupling agent (TCA) coated g-Fe2O3 particles. To evaluate the adsorption of Cu 2+ on the obtained resin NDMC-1, another two magnetic resins NDMC-0 (the precursor of NDMC-1 without hydrolyzation) and NDMO-1 (the synthesized weak acid resin using oleic acid coated g-Fe2O3) were chosen for comparison. The results showed that the carboxyl groups were formed after hydrolyzation, and NDMC-1 exhibited a greater adsorption capacity to Cu 2+ . The desorption experiment demonstrated that the desorption ratio at pH 2 (95.14%) was greatly higher than pH 3 (25.97%). Moreover, the magnetic resin NDMC-1 was proved to be stable at pH 2, extending the application of magnetic materials which were always considered to be acid-nonresistant. # 2012 Ai Min Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Bilayer-silane-coated Fe 3 O 4 nanoparticles with inner layer of tetraethoxy silane (TEOS) and outer layer of vinyltriethoxysilane (VTEO) were generated to enhance their acid resistance. These nanoparticles were copolymerized with vinylbenzyl chloride (VBC) using suspension polymerization, and then post-crosslinked. The resulting hypercrosslinked magnetic resin M150 presented specific bimodal property with large specific surface area of 1109 m 2 /g. It exhibited more excellent adsorption capacity of p -nitrophenol compared to another two magnetic adsorbents Q150 and MIEX ® . Moreover, the acid stable property of the magnetite in M150 extended its application at low pH value.

A novel magnetic anion exchange resin NDM-1 was prepared through suspension polymerization and then functionalized with ammonolysis and alkylating agents. Its application for selective removal of nitrate was performed in comparison with MIEX®. The results demonstrated that NDM-1 achieved higher efficiency in nitrate removal than MIEX® did, with or without the existence of competing anion SO42− ascribed to its longer alkyl chains on exchange sites. Combined with the advantage of easy separation due to γ-Fe2O3 implanted, the magnetic anion exchange resin NDM-1 was considered to be superior to MIEX® for nitrate removal in practical application.

Magnetic powder resin Q150 with high specific surface area of 1074 m2/g was prepared by the membrane emulsification-suspension polymerization technique. Adsoption of tetracycline on the obtained sorbent Q150 was evaluted by using the granule resin (GR) XAD-4, the powder activated carbon (PAC) 1240AC and the granule activated carbon (GAC) HD4000 for comparison. It was found that Q150 had a larger adsorption capacity, faster kinetic and easier regeneration under alkaline condition. The results suggested that the powder resin (PR) Q150 would be a promising sorbent for removing antibiotics and even other organic micropollutants from the aquatic environment.

Membrane emulsification-suspension polymerization method was introduced to prepare the monodisperse hypercrosslinked adsorbents ZQ-1 and ZQ-2 which can be used in solid phase extraction (SPE). Compared with the commercially available adsorbent LichrolutEN, ZQ-1 exhibits obvious superiority for five conventional polar analytes owing to its large specific surface area, hydrophilic groups and small particle size.