Direct Measurement of Anaerobic Biodegradability of Nonylphenol Ethoxylates (NPEOs)

Puteh, Mohd Hafiz; Stuckey, David C.; Othman, Mohd Hafiz Dzarfan

doi:10.7763/ijesd.2015.v6.676

Cited by 4 publications

(2 citation statements)

References 14 publications

(23 reference statements)

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“…Nonylphenol ethoxylates (NPEOs) are nonionic surfactants that belong to the alkylphenol ethoxylates (APEOs) family, and are used primarily in emulsifiers, detergents, wetting agents, and dispersing agents, etc. Of these, NPEOs with an average of nine ethylene oxide units (NP9EO) are well known for their commercial application [19]. The biodegradation of NPEOs in the environment leads to the formation of nonylphenol, which is a toxic xenobiotic compound, classified as an endocrine disrupter capable of interfering with living organisms.…”

Section: Introductionmentioning

confidence: 99%

Glycine–Nitrate Combustion Synthesis of Cu-Based Nanoparticles for NP9EO Degradation Applications

et al. 2020

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Copper-based nanoparticles were synthesized using the glycine–nitrate process (GNP) by using copper nitrate trihydrate [Cu(NO3)2·3H2O] as the main starting material, and glycine [C2H5NO2] as the complexing and incendiary agent. The as-prepared powders were characterized through X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy analysis. Using Cu(NO3)2·3H2O as the oxidizer (N) and glycine as fuel (G), we obtained CuO, mixed-valence copper oxides (CuO + Cu2O, G/N = 0.3–0.5), and metallic Cu (G/N = 0.7). The XRD and BET results indicated that increasing the glycine concentration (G/N = 0.7) and reducing the particle surface area increased the yield of metallic Cu. The effects of varying reaction parameters, such as catalyst activity, catalyst dosage, and H2O2 concentration on nonylphenol-9-polyethoxylate (NP9EO) degradation, were assessed. With a copper-based catalyst in a heterogeneous system, the NP9EO and total organic carbon removal efficiencies were 83.1% and 70.6%, respectively, under optimum operating conditions (pH, 6.0; catalyst dosage, 0.3 g/L; H2O2 concentration, 0.05 mM). The results suggest that the removal efficiency increased with an increase in H2O2 concentration but decreased when the H2O2 concentration exceeded 0.05 mM. Furthermore, the trend of photocatalytic activity was as follows: G/N = 0.5 > G/N = 0.7 > G/N = 0.3. The G/N = 0.5 catalysts showed the highest photocatalytic activity and resulted in 94.6% NP9EO degradation in 600 min.

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Section: Introductionmentioning

confidence: 99%

Glycine–Nitrate Combustion Synthesis of Cu-Based Nanoparticles for NP9EO Degradation Applications

et al. 2020

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“…wavelength for NPTE-conjugated beads that was absent for the control beads. The NPTE contains compounds with phenol rings which absorbs at 280nm (Puteh et al, 2015).…”

Section: Target Preparationmentioning

confidence: 99%

The Study of SELEX Methodology in the Generation of Aptamers for Environmental Contaminant Nonylphenol

Mullan¹

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Nonylphenol is an emerging organic contaminant released into the environment by anthropogenic activity. Nonylphenol is a mix of 211 branched-chain isomers collectively referred to as nonylphenol technical equivalents (NPTE), with the main isomer being 4-nonylphenol (4-NP). These isomers are capable of interfering with developmental and physiological signalling in humans, as well as numerous other terrestrial and aquatic species. Its presence has been documented in sediment and water bodies worldwide, including Aotearoa New Zealand. Due to the current limitations of environmental monitoring, researchers are becoming increasingly motivated to develop alternative techniques for detecting contaminants. Aptamer-based biosensors are of interest as their low cost, ease of use and quick analyses times meets the requirements for frequent monitoring. Aptamers are synthetic DNA molecules which provide the molecular-recognition element to biosensors. This is derived from their ability to fold into complex three-dimensional structures and form non-covalent bonds with their target molecule. Aptamers are developed through an in vitro process called systematic evolution of ligands by exponential enrichment (SELEX). The aim of this Masters study was to generate aptamers that bound single (4-NP) or multiple (NPTE) nonylphenol isomers. To achieve this, two SELEX experiments were performed against each target molecule(s) using a modified version of traditional SELEX methodology with additional counter- and negative-selection steps. Within each SELEX experiment, stringency was increased at each round in the form of Tween 20 detergent, starting at low (0.01% v/v) or high (0.1% v/v) concentrations to determine their effects on the libraries being enriched with sequences that bind either 4-NP or NPTE. Real-time PCR was used to monitor DNA quantity across selection rounds. Following this, four libraries were sequenced using Illumina sequencing and analysed using an aptamer-specific bioinformatics pipeline. The targetbinding ability of ten candidates from each library were determined using an existing characterisation technique utilising gold nanoparticles (AuNPs). Prior to characterisation, due to the nature of the target molecule, preliminary studies were conducted to assess the effects of three organic solvents on the AuNP assay. The results of this study demonstrated that the higher stringency conditions led to reduced DNA quantity and overall fewer unique sequences in the final library. Bioinformatics data demonstrated that the top clusters in libraries with sequences enriched for 4-NP under high stringency conditions, compared to low stringency conditions, contained a greater range of unique sequences. Overall, more clusters were found in the NPTE library following high stringency selection compared to both 4-NP libraries, though it is unclear whether this was derived from non-specific binding. Results from the AuNP characterisation assay showed no aptamer candidates bound to either 4-NP or NPTE, although an additional common characterisation method should also be used. Given that no aptamers were identified to bind any of the nonylphenyl isomers, the effects of stringency conditions and multi- or singletarget SELEX on aptamer characteristics could not be assessed. However, some insights from this work including the effect of detergent concentration on library populations and the use of solvents in the AuNP assay may be used to advise future experimental design for small molecule aptamer development.

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Co-metabolism of nonylphenol ethoxylate in sequencing batch reactor under aerobic conditions

et al. 2022

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Direct Measurement of Anaerobic Biodegradability of Nonylphenol Ethoxylates (NPEOs)

Cited by 4 publications

References 14 publications

Glycine–Nitrate Combustion Synthesis of Cu-Based Nanoparticles for NP9EO Degradation Applications

Glycine–Nitrate Combustion Synthesis of Cu-Based Nanoparticles for NP9EO Degradation Applications

The Study of SELEX Methodology in the Generation of Aptamers for Environmental Contaminant Nonylphenol

Co-metabolism of nonylphenol ethoxylate in sequencing batch reactor under aerobic conditions

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