Application of molecularly imprinted and non-imprinted polymers for removal of emerging contaminants in water and wastewater treatment: a review

Synthesis of a pH/temperature bi-response gallic acid magnetic imprinted polymer for extracting natural product from Galla chinensis

A pH/temperature bi-responsive gallic acid magnetic imprinted polymer (PTBG-MIP) was synthesized on a Fe3O4@SiO2@KH570 carrier using methacrylic acid (MAA), p-Vinylphenylboronic acid (p-VPBA), and N-isopropyl-acrylamide (NIPAAm) as complex functional monomers. The density functional theory (DFT) was employed to optimize the molar ratio of multi-functional monomers-template complex, which proved to be an effective tool for predicting complex configuration based on electrostatic potential (ESP) analysis and the lowest binding energy. DFT calculation and analysis determined the optimized molar ratio of 2:1:1:1 for GA-MAA-NIPAAm-p-VPBA, which showed good agreement with experimental results. The PTBG-MIP-4 obtained under the optimized conditions exhibited high pH- and temperature- dependence in rebinding the template, displaying a maximum adsorption capacity (Qe) of 62.26 mg g-1 and a highest selection factor (α) of 5.217. Additionally, the PTBG-MIP-4 exhibited exceptional physicochemical properties encompassing magnetization characteristics, morphology, surface sites distribution, and adsorption performance. The application efficiency of this imprinted composite in the extraction and purification of gallic acid from Galla chinensis was remarkably demonstrated.

Molecularly imprinted polymers (MIPs) as efficient catalytic tools for the oxidative degradation of 4-nonylphenol and its by-products

Water pollution is a current global concern caused by emerging pollutants like nonylphenol (NP). This endocrine disruptor cannot be efficiently removed with traditional wastewater treatment plants (WTPs). Therefore, this work aimed to evaluate the adsorption influence of molecularly imprinted polymers (MIPs) on the oxidative degradation (ozone and ultraviolet irradiations) of 4-nonylphenol (4-NP) and its by-products as a coadjuvant in WTPs. MIPs were synthesized and characterized; the effect of the degradation rate under system operating conditions was studied by Box-Behnken response surface design of experiments. The variables evaluated were 4-NP concentration, ozone exposure time, pH, and MIP amount. Results show that the MIPs synthesized by co-precipitation and bulk polymerizations obtained the highest retention rates (> 90%). The maximum adsorption capacities for 4-NP were 201.1 mg L-1 and 500 mg L-1, respectively. The degradation percentages under O3 and UV conditions reached 98-100% at 120 s of exposure at different pHs. The degradation products of 4-NP were compounds with carboxylic and ketonic acids, and the MIP adsorption was between 50 and 60%. Our results present the first application of MIPs in oxidation processes for 4-NP, representing starting points for the use of highly selective materials to identify and remove emerging pollutants and their degradation by-products in environmental matrices.

Synthesis, column packing and liquid chromatography of molecularly imprinted polymers for the acid black 1, acid black 210, and acid Brown 703 dyes

Molecularly imprinted polymers have been synthesized for the acid black 1, acid black 210, and acid brown 703 dyes using methacrylic acid, ethylene glycol, and azobisisobutyronitrile as the monomer, cross-linker, and initiator, respectively, in the ratio of 1 : 10 : 44 (template:monomer:cross-linker). The MIPs were used for the selective removal of their corresponding dyes. The selective nature of the MIPs towards their respective dyes was confirmed by a homemade liquid chromatography system. The resultant polymer materials were packed in a stainless steel column and checked for the separation of mixtures of dyes in liquid chromatography. The dyes complementary in structure to the imprinted cavities in the MIPs had long retention times, showing the highly selective nature of the MIPs. The pH, quantity of the MIPs, time, and concentration of the dyes were optimized for the highly efficient removal of the newly synthesized MIP adsorbents in batch adsorption studies. First-order, second-order, and intra-particle diffusion models were applied to all the three MIP-based adsorbents for their kinetic investigations towards the dyes. All the three MIPs selectively absorbed their target template molecule in the presence of four other template dyes having closely related structures with % RSD < 4% for the three batch experiments. The synthesized MIPs were characterized by FTIR, SEM imaging and liquid chromatography. FTIR results strongly confirmed the presence of hydrogen bonding interactions (600–900) between the template and the individual monomers present in the unwashed MIPs. Liquid chromatography revealed the highly selective nature of the MIPs towards their template molecules. The synthesized polymeric substances possess excellent thermal, chemical, and mechanical stability and can be reused several hundred times. The MIPs were applied in the removal of dyes from spiked water samples (river water, tap water and distilled water) where the % removal of the dyes by their corresponding MIPs was greater than 90%.

MIP synthesis for the recently emerging dyes, a new method for their characterization in liquid chromatography by packing packing the MIP particles in a stainless steel column, and their application in environmental remediation.

Arsenic(III) and Arsenic(V) Removal from Water Sources by Molecularly Imprinted Polymers (MIPs): A Mini Review of Recent Developments

The present review article summarizes the recent findings reported in the literature with regard to the use of molecularly imprinted polymers for the removal of arsenic from water and wastewater. MIPs are polymers in which a template is employed in order to enable the formation of recognition sites during the covalent assembly of the bulk phase, via a polymerization or polycondensation process. The efficiency of both arsenic species and the mechanism of removal are highlighted. The results have shown that under certain conditions, MIPs demonstrated arsenic sorption capacities of up to 130 mg/g for As(V) and 151 mg/g for As(III), while the regeneration ability was found to reach up to more than 20 cycles. The overall results showed that further development of MIPs could result in the formation of promising adsorbents for arsenic removal from waters. The use of MIPs for the removal not only of arsenic but also other inorganic contaminants is considered a very important topic, with great potential in terms of future applications in water treatment. The main advantage of these materials is that they are very selective toward the contaminant of interest. This enhanced selectivity is attributed to the incorporation of specific templates, which can then adsorb the contaminant of interest almost exclusively. Therefore, the main problem in adsorption processes is the competition for adsorption sites by other water components, for example, phosphates, nitrates, carbonates, and sulfates, which can be circumvented by the use of MI-type adsorbents.

Preparation of lightweight daisy-like magnetic molecularly imprinted polymers via etching synergized template immobilization for enhanced rapid detection of trace 17β-estradiol

17β-estradiol (E2), as one of the pharmaceutical and personal care product, frequently contaminates environmental water as estrogen pollutant and possesses great risk to human survival as well as the sustainable development of the ecosystem. Herein, to achieve an effective adsorbent system for the selective removal of E2 from the environmental water, Fe₃O₄ nanoparticles are subjected to chemical etching to reduce the overall mass and then employed as carriers to prepare a novel type of lightweight daisy-like magnetic molecularly imprinted polymers (LD-MMIPs) adopting template immobilization strategy. The LD-MMIPs based etched magnetic nanoparticles not only exhibit light mass but also have plentiful imprinted sites in the etched channels, which significantly increases the adsorption capacity for E2. The daisy-like LD-MMIPs own strong magnetic responsiveness, well crystallinity, fast binding kinetics, high adsorption amount, and excellent selectivity. Moreover, combining with HPLC, the LD-MMIPs as adsorbents have been successfully used to specifically recognize and detect trace E2 in environmental water. Thus, the proposed LD-MMIPs with high adsorption capacity hold great potential in monitoring water pollution. Additionally, this work also provides an alternative strategy for improving the adsorption capacity of magnetic molecularly imprinted polymers through a convenient chemical etching technology.

A descriptive and comparative analysis on the adsorption of PPCPs by molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) have aroused great attention as a new material for the removal or detection of pharmaceuticals and personal care products (PPCPs). However, it is not clear about the superiority and deficiency of MIPs in the process of removing or detecting PPCPs. Herein, we evaluated the performance of MIPs in the aspects of adsorption capacity, binding affinity, adsorption rate, and compatibility to other techniques, and proposed ways to improve its performance. Without regard to the selectivity of MIPs, for the PPCPs adsorption, MIPs surprisingly did not always perform better than the conventional adsorbents (non-imprinted polymers, biochar, activated carbon and resin), indicating that MIPs should be used where selectivity is crucial, for example recovery of specific PPCPs in an environmental sample extraction process. Compared to the traditional solid-phase extraction for PPCPs detection pretreatment, the usage of MIPs as substitute extraction agents could obtain high selectivity of specific substance, due to the uniformity and effectiveness of the specific sites. A promising development in the future would be to combine other simple and rapid quantitative technologies, such as electro/photochemical sensor and catalytic degradation, to realize rapid and sensitive detection of trace PPCPs.

Review on molecular imprinting technology and its application in pre-treatment and detection of marine organic pollutants

Molecular imprinting technology (MIT) has been considered as an attractive method to produce artificial receptors with the memory of size, shape and functional groups of the templates and has become an emerging technique with the potential in various fields due to recognitive specificity, high efficient selectivity and mechanical stability, which can effectively remove background interference and is suitable for the pre-treatment and analysis of trace level substances in complex matrix samples. Nearly 100 papers about the application of MIT in the detection of marine pollutants were found through Science Citation Index Expanded (SCIE). On this basis, combined with the application of MIT in other fields, the pre-treatment process of marine environmental samples was summarized and the potential of four types of different molecularly imprinted materials in the pre-treatment and detection of marine organic pollutants (including antibiotics, triazines, organic dyes, hormones and shellfish toxins) samples was evaluated, which provides the innovative configurations and progressive applications for the analysis of marine samples, and also highlights future trends and perspectives in the emerging research field.

A review on effective removal of emerging contaminants from aquatic systems: Current trends and scope for further research

Wastewater is water that has already been contaminated by domestic, industrial and commercial activity that needs to be treated before it could be discharged into some other water bodies to avoid even more groundwater contamination supplies. It consists of various contaminants like heavy metals, organic pollutants, inorganic pollutants and Emerging contaminants. Research has been doing on all types of contaminates more than a decade, but this emerging contaminants is the contaminants which arises mostly from pharmaceuticals, personal care products, hormones and fertilizer industries. The majority of emerging contaminants did not have standardized guidelines, but may have adverse effects on human and marine organisms, even at smaller concentrations. Typically, extremely low doses of emerging contaminants are found in the marine environment and cause a potential risk to the aquatic animals living there. When contaminants emerge in the marine world, they are potentially toxic and pose many risks to the health of both man and livestock. The aim of this article is to review the Emerging contaminate sources, detection methods and treatment methods. The purpose of this study is to consider the adsorption as a beneficial treatment of emerging contaminants also advanced and cost effective emerging contaminates treatment methods.

Construction of natural polymeric imprinted materials and their applications in water treatment: A review

Molecularly imprinted materials (MIMs) have been widely used in various fields, including water treatment, chemical sensing, and biotechnology, because of their specific recognition and high selectivity. MIMs are usually obtained via two successive steps, namely, (1) copolymerization and crosslinking reactions of the preassembled complex of comonomers and a specific target compound (2) and thorough removal of template molecules. Some functional polymers are directly used as supporting materials and functional groups assembled with target compound are provided to simplify the preparation of MIMs. Natural polymers, such as chitosan, cyclodextrin, sodium alginate, starch, cellulose, lignin and their derivatives, are good candidates because of their environmentally friendly properties, low costs, and abundant active functional groups. In this study, different methods for the preparation of natural polymeric MIMs were reviewed in terms of the construction of microscopic binding cavities and macroscopic visible condensed structures with different shapes. Natural polymeric MIMs in water treatment applications, such as adsorption and detection of various pollutants from aqueous solutions, were summarized. Prospects on the development of novel and high-performance natural polymeric MIMs were discussed to overcome the difficulties in their preparation and applications.

Efficient removal of norfloxacin in water using magnetic molecularly imprinted polymer

Effective and practical materials are important for the pollution control in the environment. A novel magnetic molecularly imprinted polymer (CoFe₂O₄@TiO₂-MMIP) was prepared based on the surface molecular imprinting technology combined with photocatalytic degradation and magnetic separation. The adsorption rate constant and maximum adsorption capacity of CoFe₂O₄@TiO₂-MMIP are 0.21 g mg^-1 min^-1 and 14.26 mg g^-1, respectively. The effects of experimental factors on the adsorption properties of the magnetic molecularly imprinted polymer were investigated. CoFe₂O₄@TiO₂-MMIP had selective adsorption ability towards fluoroquinolones. The adsorption efficiency was closely related to the molecular structure, molecular weight, polarity and functional groups of the target contaminant and the removal efficiency of norfloxacin was affected by another substance obviously in binary adsorption system. The adsorption-photocatalytic recycling experiment verified that CoFe₂O₄@TiO₂-MMIP could simultaneously complete the degradation of pollutants and in-situ regeneration, indicating good reusability. This material with selective adsorption and photocatalytic regeneration would have substantial attraction for application in the removal of fluoroquinolones.

Molecularly Imprinted Polymers for the Removal of Antidepressants from Contaminated Wastewater

Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressants regularly detected in the environment. This indicates that the existing wastewater treatment techniques are not successfully removing them beforehand. This study investigated the potential of molecularly imprinted polymers (MIPs) to serve as sorbents for removal of SSRIs in water treatment. Sertraline was chosen as the template for imprinting. We optimized the composition of MIPs in order to obtain materials with highest capacity, affinity, and selectivity for sertraline. We report the maximum capacity of MIP for sertraline in water at 72.6 mg g⁻¹, and the maximum imprinting factor at 3.7. The MIPs were cross-reactive towards other SSRIs and the metabolite norsertraline. They showed a stable performance in wastewater-relevant pH range between 6 and 8, and were reusable after a short washing cycle. Despite having a smaller surface area between 27.4 and 193.8 m²·g⁻¹, as compared to that of the activated carbon at 1400 m²·g⁻¹, their sorption capabilities in wastewaters were generally superior. The MIPs with higher surface area and pore volume that formed more non-specific interactions with the targets considerably contributed to the overall removal efficiency, which made them better suited for use in wastewater treatment.

Phenol removal from wastewater by surface imprinted bacterial cellulose nanofibres

In this study, we have reported a novel wastewater treatment technique by phenol imprinted bacterial cellulose (BC-MIP) nanofibres with high specificity and adsorption capacity. N-methacryloyl-(L) phenylalanine methyl ester (MAPA) functional monomer was used to create specific binding sites for the template molecule phenol via electrostatic and hydrophobic interactions. BC-MIP nanofibres were synthesized by surface imprinting approach in the presence of different amounts of total monomer (% weight), monomer/template ratio and polymerization time. Then, the nanofibres were characterized by FTIR-ATR, surface area analysis (BET), elemental analysis, scanning electron microscopy (SEM) and contact angle measurements. Adsorption studies were performed with respect to pH, temperature and ionic strength, and the adsorption capacity was calculated by using the spectrophotometer. In order to desorb the adsorbed phenol from BC-MIP nanofibres, 0.1 M NaCl solution was used. Besides, BC-MIP nanofibres were applied to real wastewater samples from Ergene basin in Turkey. The suitable equilibrium isotherm was determined as Langmuir isotherm. To evaluate the selectivity of the BC-MIP nanofibres, similar molecules were utilized as competitor molecules, which were 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol. Electrostatic interactions were found to contribute to the generation of specific recognition binding sites. The results have shown that imprinting of phenol was achieved successfully with high adsorption capacity. The phenol removal efficiency was reported up to 97%. BC-MIP nanofibres were used 10 times with a negligible decrease in adsorption capacity.

Sample treatment based on molecularly imprinted polymers for the analysis of veterinary drugs in food samples: a review

The use of veterinary drugs in medical treatments and in the livestock industry is a recurrent practice. When applied in subtherapeutic doses over prolonged times, they can also act as growth promoters. However, residues of these substances in foods present a risk to human health. Their analysis is thus important and can help guarantee consumer safety. The critical point in each analytical technique is the sample treatment and the analytical matrix complexity. The present manuscript summarizes the development, type of synthesis, characterization, and application of molecularly imprinted polymers in the separation, identification, and quantification techniques for the determination of veterinary drug residues in food samples in extraction, clean-up, isolation, and pre-concentration systems. Synthesized sorbents with specific recognition properties improve the interactions between the analytes and the polymeric sorbents, providing better analysis conditions and advantages in comparison with commercial sorbents in terms of high selectivity, analytical sensitivity, easy performance, and low cost analysis.

Pre-concentration of rosuvastatin using solid-phase extraction in a molecularly imprinted polymer and analytical application in water supply

In this work, it is shown the development and validation of innovative analytical methodology based on solid-phase extraction (SPE) with molecularly imprinted polymers (MIP) as a sorbent associated to UV-Vis spectroscopy to isolate and quantify, respectively, rosuvastatin (RSV) in water samples. For this purpose, porogenic solvent in MIP synthesis and SPE extraction parameters for MIP and non-imprinted polymers (NIP) were evaluated univariately for comparison purposes. The sorptive capacity and characterization studies by infrared spectroscopy and atomic force microscopy showed difference between MIP and NIP. The selectivity study of the MIP-RSV against other statins (simvastatin and atorvastatin) showed that the synthesized MIP can also be applied as a solid phase for isolation and quantitative pre-concentration of RSV and atorvastatin. The conjugation of SPE and UV-Vis spectroscopy in the determination of RSV in aqueous matrices led to large factor of pre-concentration (125 times), limit of detection (LOD) of 3 μg L^-1, limit of quantification (LOQ) of 10 μg L^-1, precision of 2.87% (n = 10), and accuracy of 83.1% (n = 4).

Molecularly Imprinted Polymer-Coated Probe Electrospray Ionization Mass Spectrometry Determines Phorbol Esters and Deoxyphorbol Metabolites in Jatropha curcas Leaves

In this study, a molecularly imprinted polymer-coated probe electrospray ionization mass spectrometry (MIPCPESI-MS) method was developed for detection of phorbol esters (PEs) and deoxyphorbol metabolites in Jatropha curcas leaves. Such an approach was established by sticking on a metallic needle a molecularly imprinted polymer to particularly design a MIP-coated probe for selective sampling and ionization of PEs and deoxyphorbol metabolites. By a subsequent application of a high voltage and methanol, as spray solvent, ESI was generated for direct and rapid analysis under ambient and open-air conditions. MIP-coated probe exhibited a high sampling capacity of the PEs and its metabolites in methanolic extracts of J. curcas leaves compared with the non-imprinted polymer (NIP)-coated probe. MIPCPESI-MS allowed the detection of phorbol 12,13-diacetate (PDA) from J. curcas leaves with minimal sample preparation, and with detection limit and quantification reaching 0.28 μg/mL and 0.92 μg/mL, respectively. Also, good linearity was obtained with R² > 0.99 and precision and accuracy values between 4.06-13.49% and - 1.60 to - 15.26%, respectively. The current method was successfully applied to screening methanolic extracts of six different J. curcas leaf genotypes (three toxic and three non-toxic). PDA and three PE deoxyphorbol metabolites were identified only from toxic genotypes, in which PDA was determined with concentration ranging from 222.19 ± 23.55 to 528.23 ± 19.72 μg/g. All these findings support that the MIPCPESI-MS method developed here has a high potential for the analysis of PEs in plant extracts enabling differentiation of toxic and non-toxic genotypes earlier in the leaves.

Nanocellulose-Block Copolymer Films for the Removal of Emerging Organic Contaminants from Aqueous Solutions

The prevalence of emerging organic contaminants (EOCs) in ground and surface water has sparked the search for more effective methods to remove EOCs from the environment. In pursuit of a solution for this environmental concern, herein we present the development of reusable films based on cellulose nanofibers (CNFs) and the block copolymer, poly(4-vinylpyridine-b-ethylene oxide) (P4VP-PEO) to adsorb sulfamethoxazole (SMX) as an EOC model compound. We hypothesize that the adsorption of SMX was achieved mainly by π-π interactions between the pyridine functionalities of the block copolymer and the electron deficient phenyl group of the SMX. Preceding preparation of the films, CNFs were modified with the alkoxysilane trimethoxy(2-phenylethyl)silane (TMPES) to increase their stability in aqueous solution. After the addition of P4VP-PEO, the process was completed by filtration followed by oven-drying. XPS and FTIR were employed to confirm the addition of TMPES and P4VP-PEO, respectively. Adsorption batch experiments were performed in aqueous solutions of SMX at a neutral pH, obtaining adsorptions of up to 0.014 mmol/g in a moderate time of 60 min. For the reusability tests, films were immersed in ethanol 95 wt.% to elude the adsorbed SMX, rinsed with deionized (DI) water, and dried at room temperature to be reused in a new adsorption cycle. We found that this new composite material could be reused several times with negligible loss of adsorption capacity. The films presented have been shown to be of substantial importance for water remediation as they find direct application in the adsorption of electron deficient aromatic compounds and are reusable.

Rational design and tailoring of imprinted polymeric enantioselective sensor layered on multiwalled carbon nanotubes for the chiral recognition of d-mandelic acid

Attempts have been made to investigate the feasibility of fabricating an enantiomeric sensor for the specific detection of d-mandelic acid layered on vinyl-MWCNT using molecular imprinting technology.

Molecularly imprinted polymer for the removal of diclofenac from water: Synthesis and characterization

Contaminants of Emerging Concerns (CECs) have been introduced as one type of recalcitrant pollutant sources in water. In this study, the non-steroidal anti-inflammatory drug diclofenac (DCF) has been removed from water solutions using Molecularly Imprinted Polymer (MIP), synthetized via bulk polymerization with allylthiourea (AT) as the functional monomer and using DCF as template (MIP-DCF). DCF detection has been performed by UV spectrophotometer. From the kinetic study in batch mode, approximately 100% of removal is observed by using 10mg of MIP-DCF, with an initial concentration of 5mg/L of DCF at pH7, within 3min and agitated at 25°C. In continuous flow mode study, using a cartridge pre-packed with 10mg of MIP-DCF, a high adsorption capacity of 160mgDCF/g MIP was obtained. To study the porosity of MIPs, scanning electron microscopy (SEM) has been used. In order to characterize the chemical interaction between monomer and template, the pre-polymerization mixture for MIP and DCF has also been studied by ¹H NMR. One of the chemical shift observed has been related to the formation of a complex between amine protons of thiourea group of AT with carboxylic acid on DCF. In conclusion, the developed MIP works as a good adsorbent for DCF removal, and is selective to DCF in the presence of indomethacin and ibuprofen.

Synthesis and Evaluation of a Molecularly Imprinted Polymer for the Determination of Metronidazole in Water Samples

A molecularly imprinted polymer was developed and evaluated for selective determination of metronidazole (MNZ) in wastewater. This was achieved by using sodium methacrylate as monomer, toluene as porogen, ethylene glycol dimethacrylate as crosslinker, azobisisobutyronitrile as initiator and metronidazole as template molecule to generate the selectivity of the polymer for the compound, as well as non-imprinted polymers were synthesized. Two different polymerization approaches were used, bulk and emulsion and the polymers obtained by emulsion presented higher retention percentages the MIP 2-M presented the higher retention (83%). The performed method, was validated in fortified water, showing linearity from 10 up to 1000 ng/mL; limit of detection and quantification for compound were between 3 and 10 ng/mL, respectively. Finally, the method was applied in samples of a wastewater treatment plant in the city of San Luis Potosí, México, and the concentrations of MNZ in these samples were 84.1-114 ng/mL.

Assessment of molecularly imprinted polymers (MIPs) in the preconcentration of disperse red 73 dye prior to photoelectrocatalytic treatment

Magnetic molecularly imprinted polymers (MMIPs) have become a research hotspot due to their two important characteristics: target recognition and magnetic separation. This paper presents the preparation, characterization, and optimization of an MMIP for the preconcentration of disperse red 73 dye (DR73) and its subsequent efficient degradation by photoelectrocatalytic treatment. The MMIPs were characterized by scanning electron microscopy (SEM), which revealed homogeneous distribution of the particles. Excellent encapsulation of magnetite was confirmed by transmission electron microscopy (TEM). A study of dye binding showed that the dye was retained more selectively in the MIP, compared to the NIP. The release of DR73 from the imprinted polymers into methanol and acetic acid was analyzed by UV-Vis spectrophotometry. The extracts showed higher absorbance values for MMIP, compared to MNIP, confirming greater adsorption of dye in the MMIP material. The extracts were then subjected to photoelectrocatalytic treatment. LC-MS/MS analysis following this treatment showed that the dye was almost completely degraded. Hence, the combination of MMIP extraction and photoelectrocatalysis offers an alternative way of selectively removing an organic contaminant, prior to proceeding with its complete degradation.

Removal of endocrine disrupting compounds from wastewater using polymer particles

This study evaluated the use of particles of molecularly imprinted and non-imprinted polymers (MIP and NIP) as a wastewater treatment method for endocrine disrupting compounds (EDCs). MIP and NIP remove EDCs through adsorption and therefore do not result in the formation of partially degraded products. The results show that both MIP and NIP particles are effective for removal of EDCs, and NIP have the advantage of not being as compound-specific as the MIP and hence can remove a diverse range of compounds including 17-β-estradiol (E2), atrazine, bisphenol A, and diethylstilbestrol. Removal of E2 from wastewater was also tested to determine the effectiveness of NIP in the presence of interfering substances and natural organic matter. Removal of E2 from wastewater samples was high and increased with increasing NIP. NIP represent an effective way of removing a wide variety of EDCs from wastewater.

Magnetic mesoporous imprinted adsorbent based on Fe3O4-modified sepiolite for organic micropollutant removal from aqueous solution

A novel magnetic molecularly imprinted polymer adsorbent based on a magnetic sepiolite composite was successfully prepared for the first time. It has a maximum adsorption capacity of 69.53 mg g⁻¹for atrazine.

Molecular dynamics approaches to the design and synthesis of PCB targeting molecularly imprinted polymers: interference to monomer–template interactions in imprinting of 1,2,3-trichlorobenzene

Molecular dynamic simulations identify MeOH as disrupting the FM–T interactions and reducing imprinting efficacy with 1,2,3-trichlorobenzene (2).

Evaluation of 4-substituted styrenes as functional monomers for the synthesis of theophylline-specific molecularly imprinted polymers

Six novel functional monomers (M1–M6) were examined for their ability to imprint theophylline (1). The best selectivity was observed with M2.

Fast determination of sulfonamides and their acetylated metabolites from environmental water based on magnetic molecularly imprinted polymers

Group-selective magnetic molecularly imprinted polymers (MMIPs) that can extract four widely used sulfonamide antibiotics and their acetylated metabolites from environmental water were synthesized in this study. The MMIPs with saturation magnetization value of 16.7 emu g(-1) could be separated from the environmental water samples easily by the application of an adscititious magnetic field, reducing the time consumption of pretreatment. The extraction conditions were evaluated, and optimal extraction conditions were as follows: extraction time, 25 min; amount of polymers, 90 mg; washing solvent, 30 % methanol aqueous solution; and elution solvent, methanol-acetic acid (95:5, v/v). The target analytes were detected by liquid chromatography-tandem mass spectrometry, and the detection limits of the method are in the range of 0.38-1.32 ng L(-1). The relative standard deviations of intra- and inter-day are in the range of 1.3-6.8 % and 1.7-9.1 %, respectively. The proposed method is suitable for the analysis of environmental water samples.

Duo-molecularly imprinted polymer-coated magnetic particles for class-selective removal of endocrine-disrupting compounds from aqueous environment

The removal of steroid and phenolic endocrine-disrupting compounds (EDCs) from an aqueous environment was investigated using magnetic particles encapsulated by a duo-molecularly imprinted polymer (duo-MIP). The effect of environmental variables on the binding efficiency was studied. Experimental results showed that the amount of EDCs adsorbed was neither affected by up to 10.0 mM NaCl nor significantly interfered by up to 10.0 mg/L humic acid. Negligible influence was observed from pH 3.3 to pH 6.8, but a decrease started at pH 9. Freundlich isotherm parameters indicated binding capacities in the order of DES > E2 ∼ E1 > BPA. The applicability of class-selective removal was verified using river water samples spiked with these EDCs at 10 μg/L; the binding efficiencies were 90, 90, 88, and 98 % for estrone (E1), 17β-estradiol (E2), bisphenol A (BPA), and diethylstilbestrol (DES), respectively. A reuse investigation verified constant binding capacities exhibiting <2 % reduction after seven cycles of regeneration.