The Coordination Polymer [Cu(bipy)(SO4)]n and Its Functionalization for Selective Removal of Two Types of Organic Pollutants

A new method based on coordination polymer [Cu(bipy)(SO4)]n (CP) and functionalized CP, which have a low cost and a easy preparation for selective removal of two organic pollutants in aqueous solution was proposed. Experimental results indicated that CP had excellent adsorption capacity for Alizarin red S (ARS) (1051 mg g–1) and Acid orange 7 (AO7) (989 mg g–1) by ion-exchange interaction. It was found that the kinetic and equilibrium adsorptions were well-modeled using the pseudo-second-order kinetic and the Langmuir isotherm model, respectively. Furthermore, the anionic surfactant (sodium dodecyl sulfonate, SDS) was introduced into the chain structure of CP by anionic exchange to form functionalized CP material (CP/SDS) to remove another type of organic pollution which was representative fluoroquinolone antibiotics like Enrofloxacin (EF), Sparfloxacin (SF), and Levofloxacin lactate (LL) from aqueous solution. Several conditions affecting the removal efficiency of three antibiotics including the composition ratio of SDS in adsorbent, pH, adsorbent dosage, and ionic strength were investigated. Due to the hydrophobic effect of the long methylene chain units in SDS molecular and cyclopropyl, phenyl and alkyl groups in antibiotics, the CP/SDS adsorbent have remarkable adsorption capacity for three antibiotics compared to some commercially available adsorbents, and it requires only 10 min to reach adsorption equilibrium. Thus, the results of this work demonstrate that CP and functionalized CP as the promising adsorbent materials can selectively remove two types of organic pollutants from aqueous solution. In the meantime, it exhibits the alternative exploitation approach for one-dimensional CP in environmental applicability.