Organic Micropollutants In Water Research Articles

Fast sintering of titania monoliths for photocatalytic degradation of organic micropollutants

Scalable solutions to efficiently remove organic micropollutants from water are urgently needed to address the significant adverse health effects their accumulation causes on the environment and in humans. Solutions based on slurries of titania (TiO2) nanoparticles, while effective in the lab, cannot be scaled up due to cost and environmental concerns. Conversely, titania monolithic structures are not photoactive as high sintering temperatures result in the predominance of the non-photoactive rutile phase. In this work the combination of 3D printing and fast sintering allowed, for the first time, to obtain titania monoliths which are mechanically stable and retain their photoactivity. The latter arises from the anatase-rich composition of the monoliths, a result not possible using convectional sintering methods. To demonstrate their photoactivity, the porous monoliths were used in a recirculating flow reactor to degrade primidone, a widely used drug and ubiquitous micropollutant. Results for the best performing monolith showed a quantum yield value of 1.1 × 10−5and an electrical energy per order value of 13 kWh m−3, both significantly outperforming literature data. These results show a clear route to scaling-up the fabrication of photocatalytically active titania monoliths capable of effectively degrading organic micropollutants in water, whose presence is a major health and environmental hazard.

Direct Measurement of Organic Micropollutants in Water and Wastewater Using Fluorescence Spectroscopy

Direct Measurement of Organic Micropollutants in Water and Wastewater Using Fluorescence Spectroscopy

Application of g-C3N4-PVDF membrane for the photocatalytic degradation of micropollutants in continuous flow mode: Impact of water matrix

The combination of photocatalysis with membrane separation technology allows to mitigate potential membrane fouling while degrading the organic micropollutants in water. This work is focused on the immobilization of a g-C3N4 promising photocatalyst, in the form of a g-C3N4-PVDF polymeric membrane, for the elimination of representative pharmaceutical substances from complex water matrices in a continuous flow mode under visible light irradiation. Metoprolol (MTP), venlafaxine (VEN) and diclofenac (DCF) in a mixture (at 250 μg L−1 each) were fed to the system at room temperature. The adsorption of these substances on the membrane was negligible (< 5%) in the dark. Removals of 89%, 92% and 72% for MTP, VEN and DCF, respectively, were achieved in deionized water using visible-light emitting diodes (LEDs) as light source. Moreover, the permeate flux remained constant throughout the experiments (89.5 L m−2 h−1). The membrane system was then assessed using urban wastewater treatment plant effluent, surface and tap waters, spiked with the target analytes. As expected, a worse performance was observed with these matrices, although still high removals were achieved in tap water (73%, 61% and 75%, respectively for MTP, VEN and DCF). Accordingly, the impact of the occurrence of humic acid as representative species of natural organic matter, as well as inorganic ions such as chlorides, sulphates, phosphates and carbonates, was evaluated in more detail. Clearly, humic acid and sulphates were the most impactful on the treatment performance. Finally, different scavengers were used to understand the photocatalytic mechanism, suggesting that superoxide radicals and photogenerated holes were the main active species involved in the removal of the studied micropollutants.

Degradation of 75 organic micropollutants in fresh human urine and water by UV advanced oxidation process

In household wastewater, a large proportion of organic micropollutants (OMPs) load is attributed to human urine. OMPs could pose a risk to human and environmental health when urine collected in source-separating sanitation systems is recycled as crop fertiliser. This study evaluated degradation of 75 OMPs in human urine treated by a UV-based advanced oxidation process. Fresh urine and water samples were spiked with a broad range of OMPs and fed into a photoreactor equipped with a UV lamp (185 and 254nm) that generated free radicals in situ. Degradation rate constant and the energy required to degrade 90% of all the OMPs in both matrices were determined. At a UV dose of 2060J m-2, average ΣOMP degradation of 99% (±4%) in water and 55% (±36%) in fresh urine was achieved. The energy demand for removal of OMPs in water was <1500J m-2, but for removal of OMPs in urine at least 10-fold more energy was needed. A combination of photolysis and photo-oxidation can explain the degradation of OMPs during UV treatment. Organic substances (e.g. urea, creatinine) likely inhibited degradation of OMPs in urine by competitively absorbing UV-light and scavenging free radicals. There was no reduction in the nitrogen content of urine during treatment. In summary, UV treatment can reduce the load of OMPs to urine recycling sanitation systems.

Elucidating the charge redistribution in bimetallic metal–organic frameworks: High-electron-density reactive center for removal of organic micropollutants in water

For the elimination of pharmaceutical and personal care products (PPCPs) from water, various methods and materials have been designed, while the removal effect of PPCPs is still mediocre due to the limitation of trace concentration. Therefore, constructing high-electron-density reactive centers (HRCs) for effective processing is urgent due to the potential threat to human health posed by PPCPs in water. Herein, a bimetallic metal–organic framework (BMOF-Ti/Zr6%) was synthesized by a solvothermal method with enhanced adsorption and photocatalytic capacity to address the issue. The Zr doping in metal clusters elevated the adsorption capacity of 2,2′,4,4′-tetrehydroxybenzophenone (BP-2) on BMOF-Ti/Zr6% to 4032 μmol/g, and the photocatalytic rate was more than 6 times higher than that of the pristine metal–organic framework. The enhanced adsorption and photodegradation of PPCPs on BMOFs was ascribed to the charge redistribution between Ti and Zr inducing the formation of HRCs. The electrons accumulated on HRCs altered the adsorption performance of metal sites and facilitated the generation of reactive oxygen species, which was further confirmed by theoretical calculations and indirectly validated by the interface behaviors of dissolved organic matter (DOM). Moreover, the possible reaction pathway of BP-2 degradation was explored. In addition, the BMOF-Ti/Zr6% retained more than 90% of initial adsorption capacity in photocatalytic regeneration experiments, demonstrating the potential for application in natural water matrix. These findings reinforce the understanding of charge behaviors in bimetallic materials and contribute to understand the impact of DOM in water remediation processes.

Bifunctional covalent triazine frameworks based on Ti-ON bonds for micropollutants removal: Effects of 3D extended structure and electron transport bridges

Adsorption-photocatalysis technology enables the enrichment of pollutants and the regeneration of materials, which is expected to control long-lasting organic micropollutants (OMPs) in water. In particular, taking the comprehensive advantages of composites to simultaneously improve the adsorption and photocatalytic performance is currently worth considering. Therefore, a kind of Ti/MDCTF composite with specific and strong chemical bonds (Ti-ON bonds) was synthesized by a facile approach. Compared with pristine MDCTF, 30 %-Ti/MDCTF showed an increased saturated adsorption capacity (440.56 μmol/g) and a 5.6-fold increase in photocatalytic degradation kinetic (0.315 h−1). It was comfirmed by homogenous surface diffusion model (HSDM) that the adsorption kinetics were controlled by the intra-particle diffusion. Additionally, 30 %-Ti/MDCTF exhibited a high photocatalytic regeneration efficiency (91.7 %) after 7 rounds of degradation cycles in the natural water matrix. Experimental results and theoretical analysis collaboratively showed that the porous 3D extended structure with expanded interlayer spacing promoted the mass transfer and adsorption of OMPs. Furthermore, the Ti-ON bonds acting as electron transport bridges could promote the generation of photogenerated electrons from CTF and directional movement of them to TiO2 for efficient utilization. These findings reinforce the understanding of the adsorption-promoted 3D structure and site-specific regulation of directed electron-feeding, providing a feasible and convenient solution for the removal of OMPs in water.

Mineralization of Riluzole by Heterogeneous Fenton Oxidation Using Natural Iron Catalysts

Fenton (H2O2/Fe2+) system is a simple and efficient advanced oxidation technology (AOT) for the treatment of organic micropollutants in water and soil. However, it suffers from some drawbacks including high amount of the catalyst, acid pH requirement, sludge formation and slow regeneration of Fe2+ ions. If these drawbacks are surmounted, Fenton system can be the best choice AOT for the removal of persistent organics from water and soil. In this work, it was attempted to replace the homogeneous catalyst with a heterogeneous natural iron-based catalyst for the decomposition of H2O2 into oxidative radical species, mainly hydroxyl (HO•) and hydroperoxyl radicals (HO2•). The natural iron-based catalyst is hematite-rich (α-Fe2O3) and contains a nonnegligible amount of magnetite (Fe3O4) indicating the coexistence of Fe (III) and Fe(II) species. A pseudo-first order kinetics was determined for the decomposition of H2O2 by the iron-based solid catalyst with a rate constant increasing with the catalyst dose. The catalytic decomposition of H2O2 into hydroxyl radicals in the presence of the natural Fe-based catalyst was confirmed by the hydroxylation of benzoic acid into salicylic acid. The natural Fe-based catalyst/H2O2 system was applied for the degradation of riluzole in water. It was demonstrated that the smaller the particle size of the catalyst, the larger its surface area and the greater its catalytic activity towards H2O2 decomposition into hydroxyl radicals. The degradation of riluzole can occur at all pH levels in the range 3.0–12.0 with a rate and efficiency greater than H2O2 oxidation alone, indicating that the natural Fe-based catalyst can function at any pH without the need to control the pH by the addition of chemicals. An improvement in the efficiency and kinetics of the degradation of riluzole was observed under UV irradiation for both homogeneous and heterogeneous Fenton systems. The results chromatography analysis demonstrate that the degradation of riluzole starts by the opening of the triazole ring by releasing nitrate, sulfate, and fluoride ions. The reuse of the catalyst after heat treatment at 500 °C demonstrated that the heat-treated catalyst retained an efficiency &gt;90% after five cycles. The results confirmed that the natural sources of iron, as a heterogeneous catalyst in a Fenton-like system, is an appropriate replacement of a Fe2+ homogeneous catalyst. The reuse of the heterogeneous catalyst after a heat-treatment represents an additional advantage of using a natural iron-based catalyst in Fenton-like systems.

Efficiency of Mechanochemical Ball Milling Technique in the Preparation of Fe/TiO2 Photocatalysts

Rapid population growth and widespread industrialization are the main contributing factors to the increasing contamination of the world’s diminishing freshwater resources. This work investigates Fe/TiO2 as an efficient and sustainable photocatalyst for treating organic micropollutants in water. The photocatalysts prepared by these mechanochemical methods used a high-energy ball milling technique to manipulate Fe/TiO2’s structural, optical, and catalytic properties for the photo-oxidation of 2,4-Dichlorophenol (2,4-DCP). Doping with iron effectively reduced the band gap of rutile TiO2 from 3 to 2.22 eV. By reducing the ball/powder ratio from 34 to 7, the removal efficiency of 2,4-DCP increased from 65.2 to 84.7%. Measuring the TOC indicated 63.5 and 49.4% mineralization by Fe/TiO2-7 and rutile TiO2, respectively, after 24 h. The energy yields for the Fe/TiO2 and rutile TiO2 were 0.13 and 0.06 g 2,4-DCP/kW h, respectively.

Nanocomposite Polymeric Membranes for Organic Micropollutant Removal: A Critical Review.

The prevalence of organic micropollutants (OMPs) and their persistence in water supplies have raised serious concerns for drinking water safety and public health. Conventional water treatment technologies, including adsorption and biological treatment, are known to be insufficient in treating OMPs and have demonstrated poor selectivity toward a wide range of OMPs. Pressure-driven membrane filtration has the potential to remove many OMPs detected in water with high selectivity as a membrane's molecular weight cutoff (MWCO), surface charge, and hydrophilicity can be easily tailored to a targeted OMP's size, charge and octanol-water partition coefficient (Kow). Over the past 10 years, polymeric (nano)composite microfiltration (MF), ultrafiltration (UF), and nanofiltration (NF) membranes have been extensively synthesized and studied for their ability to remove OMPs. This review discusses the fate and transport of emerging OMPs in water, an assessment of conventional membrane-based technologies (NF, reverse osmosis (RO), forward osmosis (FO), membrane distillation (MD) and UF membrane-based hybrid processes) for their removal, and a comparison to the state-of-the-art nanoenabled membranes with enhanced selectivity toward specific OMPs in water. Nanoenabled membranes for OMP treatment are further discussed with respect to their permeabilities, enhanced properties, limitations, and future improvements.

Cucurbit[5]uril-based porous polymer material for removing organic micropollutants in water

Organic micropollutants pose a tremendous challenge to global water resources, for nonbiodegradable synthetic chemicals, especially. In this investigation, we loaded Cucurbit [5]uril on polymer BPEIH to prepare supramolecular polymer Q[5]@BPEIH with pore structure, which is used to adsorb and remove organic micropollutants in water. The experimental results show that the adsorbent can remove organic micropollutants from water quickly and with high loading, which is better effect than that of traditional activated carbon. In particular, the polymer is an excellent adsorbent for 2,7-dihydroxynaphthalene and Neutral Red pollutants. It also has classy adsorption properties for 1-naphthylamine, Amaranth, Metallic Yellow, 8-hydroxy-1,3,6-trisulfonic acid pyrene, Methyl Orange and Crystal Violet. This adsorbent can also adsorb I 2 . When the adsorption tends to equilibrium, the calculated adsorption rate is 87.2%. These outstanding adsorption effects show that this adsorbent can help to remove a variety of micropollutants in the process of wastewater treatment. More importantly, Q[5]@BPEIH that we designed and synthesized has the characteristics of low synthesis cost, simple synthesis and preparation process, high product yield, fast adsorption speed and strong removal ability. The admirable removal ability of pollutant proved the prospect of Q [5]@BPEIH for rapid sewage disposal. • Synthesis and preparation of a new adsorbent of supramolecular polymer Q[5]@BPEIH. • Adsorption kinetics and adsorption model of Q[5]@BPEIH for organic micropollutants. • The advantages of the adsorbent such as: simple preparation, high product yield, strong removal ability and so on. • The admirable removal ability of pollutant proved the prospect of Q[5]@BPEIH for rapid sewage disposal.

Influence of chemical structure of organic micropollutants on the degradability with ozonation

The increasing environmental problems due to various organic micropollutants in water cause the search of suitable additional water treatment methods. Gaining experimental data for the large amount and variety of pollutants would consume a lot of time as well as economic and ecologic resources. An alternative approach is predictive quantitative structure-property relationship (QSPR) modeling, which establishes a correlation between the structural properties of a molecules with a biological, physical, or chemical property. Therefore, in this study, QSPR modeling has been conducted using extensive validation techniques and statistical test to investigate the structural influence on the degradability of organic micropollutants with ozonation. In contrast to most of the other studies, the underlying dataset - rate constants for 92 organic molecules - were obtained under standardized conditions with defined experimental parameters. QSPR modeling was executed using a combination of the software PaDEL for descriptor calculation and QSARINS for the modeling process respecting all five OECD-requirements for applicable QSAR/QSPR-models. The final model was selected using a multi-criteria decision-making tool to evaluate the model quality based on all calculated statistical quality parameters. The model included 10 selected descriptors and fingerprints and showed good regression abilities, predictive power, and stability (R² = 0.8221, CCCtr = 0.9024, Q²loo = 0.7436, R²ext = 0.8420, Q²F1 = 0.8104). The applicability domain of the QSPR model was defined and an interpretation of selected model descriptors has been connected to previous experimental studies. A significant influence of the interpretable descriptors was put into experimental context and compared with previous studies and models. For example, the molar refractivity as a measure of size and polarizability of a molecule and the occurrence of important substructures such as a formamide group seem to decrease the removal rate constant. The contribution of lone electrons entering into resonance as well as the occurrence of fused rings were identified as influences for the increase of the degradability of micropollutants by ozonation.

Rapid and selective oxidation of refractory sulfur-containing micropollutants in water using Fe-TAML/H2O2

Developments of Fe-TAML/H2O2 systems were conducted for the removal of refractory organic micropollutants in water. Herein, we investigated degradation of 68 structurally diverse sulfur-containing micropollutants (ng/L–μg/L) in water by Fe-TAML/H2O2, and developed predictive models of the reactivity of Fe-TAML/H2O2 using micropollutant, Fe-TAML and H2O2 data. The micropollutants were usually degraded rapidly in water within 20 min, and the kobs values (0.0054 to > 0.47 min−1) drastically varied with compounds and/or solution pH. Static complexation and electron transfer between Fe-TAML and compounds were proposed for the high reactivity and selectivity of Fe-TAML/H2O2 toward micropollutant over naturally occurring dissolved organic matter (DOM). The mechanism-based reaction models of Fe-TAML/H2O2 were well extrapolated to large diversities of organic compounds and various types of water. This study indicates that Fe-TAML/H2O2 systems may provide a technical basis for the removal of micropollutants in water, despite the presence of high levels of natural water components.

Rapid photodegradation of organic micro-pollutants in water using high-intensity pulsed light

The rising concentration of organic micro-pollutants (OMPs) in water resources has become a major concern for aquatic ecosystems and human health. Advanced oxidation processes (AOPs), based on ultraviolet (UV) photolysis and photochemical reactions, have been suggested for the degradation of various micropollutants present in water and wastewater. However, the application of these methods on large scale is limited due to the long treatment times. Here we evaluate the efficiency of high-intensity pulsed light treatment (HIPL) for the degradation of organic compounds in aqueous conditions. A solution containing 11 OMPs was treated with short (<2 ms) and high-intensity light pulses produced by a Xenon flash lamp. It was observed that the HIPL parameters, such as the number of pulses and optical energy dose, have a significant impact on the efficiency of the treatment. The main advantage of HIPL is the fast kinetics that allows efficient photodegradation of OMPs from the aqueous solution rapidly and within milliseconds. The present work showcases the potential of HIPL technique for the post-treatment of contaminated water containing pharmaceuticals and endocrine disruptor compounds.

Cold atmospheric plasma technology for removal of organic micropollutants from wastewater\u2014a review

Water bodies are being contaminated daily due to industrial, agricultural and domestic effluents. In the last decades, harmful organic micropollutants (OMPs) have been detected in surface and groundwater at low concentrations due to the discharge of untreated effluent in natural water bodies. As a consequence, aquatic life and public health are endangered. Unfortunately, traditional water treatment methods are ineffective in the degradation of most OMPs. In recent years, advanced oxidation processes (AOPs) techniques have received extensive attention for the mineralization of OMPs in water in order to avoid serious environmental problems. Cold atmospheric plasma discharge-based AOPs have been proven a promising technology for the degradation of non-biodegradable organic substances like OMPs. This paper reviews a wide range of cold atmospheric plasma sources with their reactor configurations used for the degradation of OMPs (such as organic dyes, pharmaceuticals, and pesticides) in wastewater. The role of plasma and treatment parameters (e.g. input power, voltage, working gas, treatment time, OMPs concentrations, etc.) on the oxidation of various OMPs are discussed. Furthermore, the degradation kinetics, intermediates compounds formed by plasma, and the synergetic effect of plasma in combination with a catalyst are also reported in this review.Graphic

Insights into the wavelength-dependent photolysis of chlorite: Elimination of carbamazepine and formation of chlorate

Simultaneous removal of chlorite (ClO2−) and organic micro-pollutants (OMPs) by the irradiation of UV is a novel process. In this study we used UV light emitting diode (UV-LED) as a new UV source to systematically investigate the effect of UV wavelength (255, 285, 365 nm) on the simultaneous removal of carbamazepine (CBZ) and ClO2−. Removal of both CBZ and ClO2− followed the order of 255, 285, and 365 nm. Formation of hydroxyl radical and reactive chlorine species (RCS) were confirmed during the photolysis of ClO2− using probe compounds. RCS were always the predominant contributor to the degradation of CBZ in UV-LED/ClO2− system. The impacts of ClO2− dosage, pH, bicarbonate/carbonate (HCO3−/CO32−), and the effect of natural organic matter (NOM) on CBZ degradation were also evaluated. This study identified the products produced by CBZ through possible degradation pathways during the transformation process. Further, the amount of ClO2− may affect the amount of chlorate produced in UV/ClO2− system. Overall, our research provides an in-depth analysis of the effects of UV wavelength on the simultaneous removal of ClO2− and OMPs in water.

Effective and Rapid Removal of Polar Organic Micropollutants from Water by Amide Naphthotube‐Crosslinked Polymers

AbstractIt is challenging to remove polar organic micropollutants from water through adsorption‐mediated processes. Macrocycle‐crosslinked polymers were recently shown to be effective adsorbents for nonpolar or charged organic micropollutants through specific host–guest binding, but are rarely used for the treatment of neutral and polar organic micropollutants. This is due to the challenge of recognizing polar molecules in water by macrocyclic hosts. In this research, we report two amide naphthotube‐crosslinked polymers which can effectively and rapidly adsorb a wide scope of polar organic micropollutants from water through biomimetic molecular recognition. Amide naphthotubes possess hydrogen bonding sites in their deep hydrophobic cavities and can effectively bind polar organic micropollutants in water through the hydrophobic effects and shielded hydrogen bonds. The cross‐linked polymers containing amide naphthotubes are even able to remove a complex mixture of organic micropollutants from water and the used materials can be easily regenerated through washing with MeOH or EtOH. This research provides a solution for the treatment of polar organic micropollutants by using biomimetic molecular recognition in water.

Effective and Rapid Removal of Polar Organic Micropollutants from Water by Amide Naphthotube-Crosslinked Polymers.

It is challenging to remove polar organic micropollutants from water through adsorption-mediated processes. Macrocycle-crosslinked polymers were recently shown to be effective adsorbents for nonpolar or charged organic micropollutants through specific host-guest binding, but are rarely used for the treatment of neutral and polar organic micropollutants. This is due to the challenge of recognizing polar molecules in water by macrocyclic hosts. In this research, we report two amide naphthotube-crosslinked polymers which can effectively and rapidly adsorb a wide scope of polar organic micropollutants from water through biomimetic molecular recognition. Amide naphthotubes possess hydrogen bonding sites in their deep hydrophobic cavities and can effectively bind polar organic micropollutants in water through the hydrophobic effects and shielded hydrogen bonds. The cross-linked polymers containing amide naphthotubes are even able to remove a complex mixture of organic micropollutants from water and the used materials can be easily regenerated through washing with MeOH or EtOH. This research provides a solution for the treatment of polar organic micropollutants by using biomimetic molecular recognition in water.

Mutagenicity, health risk, and disease burden of exposure to organic micropollutants in water from a drinking water treatment plant in the Yangtze River Delta, China

A wide variety of organic micropollutants in drinking water pose a serious threat to human health. This study was aimed to reveal the characteristics of organic micropollution profiles in water from a drinking water treatment plant (DWTP) in the Yangtze River Delta, China and investigate the mutagenicity, health risk and disease burden through mixed exposure to micropollutants in water. The presence of organic micropollutants in seven categories in organic extracts (OEs) of water from the DWTP was determined, and Ames test was conducted to test the mutagenic effect of OEs. Meanwhile, health risk of exposure to organic micropollutants in finished water through three exposure routes (ingestion, dermal absorption and inhalation) was assessed with the method proposed by U.S. EPA, and disability-adjusted life years (DALYs) were combined to estimate the disease burden of cancer based on the carcinogenic risk (CR) assessment. The results showed that 28 organic micropollutants were detected in the raw and finished water at total concentrations of 967.28 ng/L and 1073.45 ng/L, respectively, of which phthalate esters (PAEs) were the dominant category (95.79% in the raw water and 96.61% in the finished water). Although the results of the Ames test for OEs were negative and the non-carcinogenic hazard index of the organic micropollutants in the finished water was less than 1 in all age groups, the total CR was 2.17 × 10−5, higher than the negligible risk level (1.00 × 10−6). The total DALYs caused by the organic micropollutants in the finished water was 2945.59 person-years, and the average individual DALYs was 2.21 × 10−6 per person-year (ppy), which was 2.21 times the reference risk level (1.00 × 10−6 ppy) defined by the WHO. Exposure to nitrosamines (NAms) was the major contributor to the total CR (92.06%) and average individual DALYs (94.58%). This study demonstrated that despite the negative result of the mutagenicity test with TA98 and TA100 strains, the health risk of exposure to organic micropollutants in drinking water should not be neglected.

Construction of hydroxyl functionalized magnetic porous organic framework for the effective detection of organic micropollutants in water, drink and cucumber samples

Organic micropollutants have been extensively detected in environmental waters, posing severe hazards to organisms and humans. Effective detection of micropollutants in environmental water and food samples is of significant importance. Herein, a novel magnetic porous organic framework (labeled as M-Qu-POF) was synthesized using natural quercetin as building units via a facile azo-coupling reaction for the first time. Featuring with good magnetism, intrinsic porosity, high surface area and hydrophilic-lipophilic (amphiphilic) structure, the M-Qu-POF displayed high adsorption capacity for phenylurea herbicides (PUHs) pollutants. The adsorption mechanism was investigated by theory calculation, confirming that the hydrogen bonds interaction, π-π interactions and electrostatic interactions play an important role in the adsorption. With the M-Qu-POF as adsorbent, a magnetic solid phase extraction-high performance liquid chromatography method was first established for simultaneous enrichment and detection of six PUHs in environmental water, tea drink and cucumber samples. Under the optimized experimental conditions, good linear range, low detection limits and high enrichment factors were obtained. The method was successfully applied for determination of PUHs in environmental water, tea drink and cucumber samples with satisfactory recoveries (80.0–118%). The result demonstrates that the M-Qu-POF material has a good application prospect in the detection of other organic micropollutants.

A Calix[4]arene-crosslinked polymer for rapid adsorption of cationic dyes in water

Dyes are indispensable in the textile industry and are very difficult to degrade due to the presence of two or more benzene rings in their structures. However, the purification of water resources is currently an urgent issue. In this study, a trichlorotriazine-derived calix[4]arene and 1,3,5-tris(4-aminophenyl) benzene were crosslinked to generate a calix[4]arene crosslinked polymer that can serve as a highly efficient adsorbent for separating cationic dyes from water. This research provides evidence for the efficiency of the polymer to adsorb various organic micropollutants in water via batch adsorption experiments. In particular, this polymer exhibited a removal efficiency over 99.6% and 99.4% for methylene blue and toluidine blue within 5 min, respectively. The kinetic results showed that the adsorption process of this polymer for organic dyes could be described with quasi-second-order models, and Langmuir isotherm adsorption models demonstrated that the maximum equilibrium adsorption capacity for methylene blue and toluidine blue was reached to 1806.82 and 2161.32 mg g−1, respectively. These observations suggest that the adsorption is mainly dependent on the electrostatic interactions, π−π interactions, and hydrogen bonding between the polymer and the organic dyes. Furthermore, the adsorption capacities of the adsorbent were maintained at high levels after five cycles. Its excellent adsorption capability and recyclability make this polymer a promising candidate for potential applications in water purification.