Limits...
Application of molecularly imprinted polymers to selective removal of clofibric acid from water.

Dai C, Zhang J, Zhang Y, Zhou X, Liu S - PLoS ONE (2013)

Bottom Line: Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model.The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS).In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.

View Article: PubMed Central - PubMed

Affiliation: College of Civil Engineering, Tongji University, Shanghai, China ; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.

ABSTRACT
A new molecularly imprinted polymer (MIP) adsorbent for clofibric acid (CA) was prepared by a non-covalent protocol. Characterization of the obtained MIP was achieved by scanning electron microscopy (SEM) and nitrogen sorption. Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model. Scatchard plot analysis revealed that two classes of binding sites were formed in the MIP with dissociation constants of 7.52 ± 0.46 mg L(-1) and 114 ± 4.2 mg L(-1), respectively. The selectivity of MIP demonstrated higher affinity for CA over competitive compound than that of non-imprinted polymers (NIP). The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.

Show MeSH

Related in: MedlinePlus

Effect of TDS on the removal efficiency of CA by different adsorbents (mean ±SD, n = 3).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3814990&req=5

pone-0078167-g006: Effect of TDS on the removal efficiency of CA by different adsorbents (mean ±SD, n = 3).

Mentions: The MIP synthesized was used to remove CA from spiked surface water from the Huangpu River. The adsorption capacity of MIP for CA was compared in the presence of matrix parameters such as dissolved organic matter and total dissolved solids (TDS). The two Qmax values for the adsorption of CA from surface water by MIP were 131±4 mg g−1 and 359±11 mg g−1, which was slightly lower than the adsorption capacity from deionized water (p>0.05). This is expected due to the presence of many different organic and inorganic species in surface water which can also bind onto MIP, hence reducing the effective adsorption of MIP for CA. It is well known that polyvinyl pyridine is efficient ligand for divalent metal ions such as Ca2+, Mg2+, etc., and can form coordinate bonds with these kinds of metal ions [27]. Therefore the effect of the inorganic ion on the removal of CA by the MIP was studied. The inorganic ions in surface water can be represented by total dissolved solids (TDS) where organic fraction was removed by oxidation of water samples with K2Cr2O2 in acidic conditions at 150°C [31]. The concentration of TDS in Huangpu River was about 560 mg L−1, and the chemical oxygen demand (COD) was about 40 mg L−1. The interference of inorganic ions was studied by diluting the surface water sample with deionized water and then removal efficiency of CA by MIP was evaluated for CA (Fig. 6). As shown in Fig. 6, when the TDS concentration was about 420 mg L−1, there was no significant change in removal efficiency of CA by MIP (p>0.05). This indicated that the adsorption of MIP would be completely retained in the presence of TDS up to 420 mg L−1. However, the removal efficiency of CA by MIP decreased as the TDS value exceeds 420 mg L−1. This observation may be interfered that the major inorganic ions such as Ca2+ and Mg2+ could form complexes with functional monomer (2-VP) in the polymer matrix, which may influence the adsorption capacity of MIP. Additionally, it should be emphasized that the removal efficiency of MIP for CA was higher than the uptake by NIP and powdered activated carbon (PAC) under similar conditions (p<0.05). Therefore the MIP specific characteristics were sufficient to remove CA at low concentration from water and wastewater.


Application of molecularly imprinted polymers to selective removal of clofibric acid from water.

Dai C, Zhang J, Zhang Y, Zhou X, Liu S - PLoS ONE (2013)

Effect of TDS on the removal efficiency of CA by different adsorbents (mean ±SD, n = 3).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814990&req=5

pone-0078167-g006: Effect of TDS on the removal efficiency of CA by different adsorbents (mean ±SD, n = 3).
Mentions: The MIP synthesized was used to remove CA from spiked surface water from the Huangpu River. The adsorption capacity of MIP for CA was compared in the presence of matrix parameters such as dissolved organic matter and total dissolved solids (TDS). The two Qmax values for the adsorption of CA from surface water by MIP were 131±4 mg g−1 and 359±11 mg g−1, which was slightly lower than the adsorption capacity from deionized water (p>0.05). This is expected due to the presence of many different organic and inorganic species in surface water which can also bind onto MIP, hence reducing the effective adsorption of MIP for CA. It is well known that polyvinyl pyridine is efficient ligand for divalent metal ions such as Ca2+, Mg2+, etc., and can form coordinate bonds with these kinds of metal ions [27]. Therefore the effect of the inorganic ion on the removal of CA by the MIP was studied. The inorganic ions in surface water can be represented by total dissolved solids (TDS) where organic fraction was removed by oxidation of water samples with K2Cr2O2 in acidic conditions at 150°C [31]. The concentration of TDS in Huangpu River was about 560 mg L−1, and the chemical oxygen demand (COD) was about 40 mg L−1. The interference of inorganic ions was studied by diluting the surface water sample with deionized water and then removal efficiency of CA by MIP was evaluated for CA (Fig. 6). As shown in Fig. 6, when the TDS concentration was about 420 mg L−1, there was no significant change in removal efficiency of CA by MIP (p>0.05). This indicated that the adsorption of MIP would be completely retained in the presence of TDS up to 420 mg L−1. However, the removal efficiency of CA by MIP decreased as the TDS value exceeds 420 mg L−1. This observation may be interfered that the major inorganic ions such as Ca2+ and Mg2+ could form complexes with functional monomer (2-VP) in the polymer matrix, which may influence the adsorption capacity of MIP. Additionally, it should be emphasized that the removal efficiency of MIP for CA was higher than the uptake by NIP and powdered activated carbon (PAC) under similar conditions (p<0.05). Therefore the MIP specific characteristics were sufficient to remove CA at low concentration from water and wastewater.

Bottom Line: Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model.The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS).In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.

View Article: PubMed Central - PubMed

Affiliation: College of Civil Engineering, Tongji University, Shanghai, China ; State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.

ABSTRACT
A new molecularly imprinted polymer (MIP) adsorbent for clofibric acid (CA) was prepared by a non-covalent protocol. Characterization of the obtained MIP was achieved by scanning electron microscopy (SEM) and nitrogen sorption. Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model. Scatchard plot analysis revealed that two classes of binding sites were formed in the MIP with dissociation constants of 7.52 ± 0.46 mg L(-1) and 114 ± 4.2 mg L(-1), respectively. The selectivity of MIP demonstrated higher affinity for CA over competitive compound than that of non-imprinted polymers (NIP). The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.

Show MeSH
Related in: MedlinePlus