•Hydrolysis lignin was catalytically pyrolyzed with metal doped zirconia catalysts.•Catalysts basicity, lig:cat ratio and temperature affect product distribution.•Na/ZrO2 enhanced monomeric phenolic ...compounds yield at 500 °C.•Under best conditions, Na/ZrO2 resulted in ~28 wt% monomeric phenols.•Successful Na/ZrO2 regeneration requires T ≥ 900 °C.
Alkyl and alkoxy phenols are desirable products from the catalytic depolymerisation of lignin. In this work, ex-situ catalytic pyrolysis of Etek lignin in presence of Na, Ce, NiCe, MgCe, Fe and FePd on ZrO2 was studied. The largest combined yield of monomeric phenolics and alkylphenols was produced by Na/ZrO2 catalysts. A parametric study of the most promising Na/ZrO2 then resulted in using a catalyst:lignin ratio of 3:1 at 500 °C as the best option, enhancing at 17.5 wt% the recovery of total phenolics including 6 wt% alkyl phenols, which is equivalent to 27.8 wt% and 9.5 wt% of the starting lignin in Etek lignin waste. The study of the catalyst basicity indicates that the mild basicity of Na/ZrO2 was mostly responsible for the enhanced mono phenols recovery. Due to formation of thermally stable Na2CO3 during pyrolysis, successful Na/ZrO2 regeneration requires temperature of 900 °C or higher.
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•Occurrence of contaminants of emerging concern (CEC) in bottled water is compiled.•The findings related to CECs’ possible sources and their risks are summarized.•The bottle type ...plays an important role in the contamination level.•Water in plastic bottles is more polluted than in glass bottles.•The CEC levels except for MPs do not raise a safety concern for the human.
Contaminants of emerging concern (CECs) have recently been detected in bottled water and have brought about discussions on possible risks for human health. However, a systematic review of CECs in bottled water is currently lacking due to the relatively new introduction and/or detection of these pollutants. Hence, this paper reviews the existing studies on the presence of six major groups of emerging contaminants including microplastics (MPs), pharmaceuticals and personal care products (PPCPs), bisphenol A (BPA), phthalates, alkylphenols (APs), and perfluoroalkyl and polyfluoroalkyl substances (PFASs) in bottled water from different countries. Also, the findings related to CECs’ levels, their possible sources, and their risks are summarized. The gathered data indicate that MPs within the size range of 1−5 μm are the most predominant and potentially toxic classes of MPs in bottled water. In addition, PPCPs, PFASs, APs, and BPA occur in concentration levels of ng/L, while phthalates occur in the μg/L level in bottled water. The bottle type plays an important role in the contamination level. As expected, water in plastic bottles with plastic caps is more polluted than in glass bottles. However, other sources of contamination such as contact materials during cleaning, bottling, and storage are not negligible. Based on the gathered data in this review, the CEC levels except for MPs (no threshold values) in bottled water of most countries do not raise a safety concern for the human. However, the occurrence of individual CECs and their association in bottled water need more accurate data to understand their own/synergistic effects on human health.
Regioselective hydroxylations of aromatic compounds are useful reactions but often lack appropriate catalysts. Here a group of P450BM3 mutants (R47I/A82F/A328F, R47L/Y51F/F87V/L188P/I401P, ...R47I/Y51F/F87V, R47L/Y51F/F87V/L181Q/L188P/I401P, and R47I/F87V/L188P) were developed as unique catalysts for the p-hydroxylation of m-alkylphenols 1a–e with high regioselectivity (91–99%) and conversion (95–99%) to produce the corresponding useful and valuable m-alkylbenzene-1,4-diols 2a–e, respectively. The mutated hydroxylases were developed by protein engineering of P450BM3 monooxygenase via site-directed mutagenesis based on designed mutations to reshape the substrate binding pocket and access channel. Several engineered P450BM3 mutants showed good catalytic efficiency (k cat/K M of 234–381 mM–1 min–1) for the p-hydroxylations of m-alkylphenols 1a–e, respectively. Molecular docking and simulation gave some insights into the structure-based understanding of the enhanced regioselectivity and activity for the developed P450BM3 mutants, including the shorter distance between heme-oxygen atom and C4-carbon (p-position) of substrates than the wild-type enzyme in the catalytic pockets. Preparative biohydroxylations of m-alkylphenols 1a–e were demonstrated by using E. coli cells coexpressing individual P450BM3 mutants and glucose dehydrogenase GDH, giving high-yielding synthesis of useful and valuable m-alkylbenzene-1,4-diols 2a–e.
Organic pollutants with high solid–water equilibrium partition coefficients are adsorbed into solid particles and are easily ingested by benthic organisms, potentially causing dietborne toxicity. ...Whether dietborne toxicity is more important than waterborne toxicity for such chemicals remains to be determined. In this study, we identify the most relevant uptake route for the toxicity of two alkylphenols, 4-tert-butylphenol (4tBP), and 4-tert-octylphenol (4tOP). To achieve this, 6-day toxicity tests under two exposure conditions, namely dietary exposure (clean water + contaminated food) and combined exposure (contaminated water + contaminated food) were conducted on a benthic ostracod, Heterocypris incongruens. The toxicologically important exposure routes were confirmed by the consistency of dietary and aqueous dose–response relationships under different exposure conditions. During the test, frequent renewal of water and food was performed to reduce variability in the exposure conditions. The results showed that, under the equilibrium condition, the dietary exposure route was toxicologically more important than the aqueous route for 4tBP, whereas the waterborne exposure route was more important than the dietary exposure route for 4tOP. This study provides a novel approach to identify the most relevant uptake pathways for chemical toxicity, which better explains the importance of exposure routes in toxicity effects.
During the last 10years, the appearance of emerging organic compounds described as endocrine disrupters in wastewaters and water resources has become a major concern for both society and public ...health authorities, the whole industrial world and the agricultural sector. Endocrine disrupting compounds are found in various environmental compartments such as water, sediments, soils and atmosphere, as a result of their wide usage. Numerous products are concerned including surfactants, industrial additives and formulations, pharmaceuticals, and also personal care products. However, the existing conventional water treatment plants were not designed for these new contaminants. In the present study, an overview of the literature on methods for the elimination (removal and/or degradation) of emerging trace organic contaminants is presented. This review is limited to details of the treatment of one class of endocrine disrupters, namely alkylphenols and their polyethoxylate derivatives, which are suspected to interfere with the hormonal system of wildlife. The technologies proposed for alkylphenol treatment include membrane treatment using biological (membrane bioreactors) or physical processes (membrane filtration such as nanofiltration), biotechnological-based methods (biofilms, immobilized enzymes, etc.), adsorption-oriented processes using conventional (activated carbons) or nonconventional adsorbents (clays, cyclodextrin, etc.), and advanced oxidation processes (photocatalysis, photolysis, and sonochemistry). Examples are taken from the literature to illustrate various features of the technologies used in decontamination methods. Among them, photocatalytic oxidation is an interesting tool for alkylphenol treatment due to its potential to reach complete mineralization.
Funneling and functionalization of a mixture of lignin‐derived monomers into a single high‐value chemical is fascinating. Reported herein is a three‐step strategy for the production of terephthalic ...acid (TPA) from lignin‐derived monomer mixtures, in which redundant, non‐uniform substitutes such as methoxy groups are removed and the desired carboxy groups are introduced. This strategy begins with the hydro‐treatment of corn‐stover‐derived lignin oil over a supported molybdenum catalyst to selectively remove methoxy groups. The generated 4‐alkylphenols are converted into 4‐alkylbenzoic acids by carbonylation with carbon monoxide. The Co‐Mn‐Br catalyst then oxidizes various alkyl chains into carboxy groups, transforming the 4‐alkylbenzoic acid mixture into a single product: TPA. For this route, the overall yields of TPA based on lignin content of corn stover could reach 15.5 wt %, and importantly, TPA with greater than 99 % purity was obtained simply by first decanting the reaction mixture and then washing the solid product with water.
PET project: Terephthalic acid (TPA) is obtained in high yield and purity from corn stover lignin by a three‐step conversion strategy. Thus, TPA is available for making polyethylene terephthalate and other plastics.
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•A multi-templates MIP was prepared by surface molecularly imprinting technology.•The MIP showed remarkable adsorption capacity, kinetics and reusability.•The MIP exhibited good ...adsorption selectivity towards alkylphenols.•The MIP was used as the MSPE adsorbent for alkylphenols detection.•Real water samples were analyzed with satisfactory results.
A novel multi-templates molecularly imprinted polymer (MIP) was prepared on the surface of mesoporous silica coated magnetic graphene oxide (MGO@mSiO2), and applied for the rapid and selective detection of alkylphenol compounds including bisphenol A (BPA), 4-tert-octylphenol (4-tert-OP) and 4-nonylphenol (4-NP) in water. The synthesized composite was characterized by Fourier transform infrared spectrometer, vibrating sample magnetometer, transmission electron microscopy and Brunauer-Emett-Teller surface area analyzer. The MIP showed high adsorption capacity, good selectivity and fast kinetic for these alkylphenols. The maximum adsorption capacities of the MIP for BPA, 4-tert-OP and 4-NP were 16.81, 35.97 and 61.73 mg g−1, respectively, which were significantly higher than those of the non-molecularly imprinted polymer (NIP) due to the imprinting effect. The adsorption of alkylphenols reached equilibrium within 30 min, and followed pseudo-second-order kinetic model and Langmuir model well. The MIP exhibited good sorption selectivity towards BPA, 4-tert-OP and 4-NP, and could be reused 5 times. Furthermore, a new method for ultrasensitive determination of BPA, 4-tert-OP and 4-NP in water by high performance liquid chromatography was developed, using MIP-based magnetic solid-phase extraction coupled with dispersive liquid-liquid microextraction. Under the optimum conditions, the limits of detection (LODs) for BPA, 4-tert-OP and 4-NP were 0.013, 0.010 and 0.010 μg L−1, respectively. The proposed method was used to the detection of BPA, 4-tert-OP and 4-NP in real water samples, with spiked recoveries of 81.5–104.1% and relative standard deviations (RSDs) of 1.0–7.6%, indicating the multi-templates MIP could be a promising adsorbent for separation and analysis of alkylphenols.
A fast methodology to quantify 4-
tert
-octylphenol (4-t-OP) and 4-nonylphenol (4-NP) and their mono- and di-ethoxylates was developed, validated, and applied to real wastewater samples. Dispersive ...liquid-liquid microextraction was employed as a sample preparation step, leading to a pre-concentration factor of roughly 30. Analysis was carried out by liquid chromatography-tandem mass spectrometry with electrospray ionisation in multiple reaction monitoring mode. Average recoveries were generally between 80 and 120% for both the alkylphenols and their mono- and di-ethoxylates in influent and effluent wastewater. A minimum of 5 concentration levels per compound, ranging between 1 and 500 ng/mL, were prepared to construct calibration curves making use of isotopically labelled internal standards. The method presented good linearity and repeatability over the whole range of concentrations. Taking into account the concentration factor, and the recovery of the compounds, lower limits of quantification obtained in effluent wastewater were 0.04 ng/mL for 4-t-OP and 0.14 ng/mL for 4-NP, complying with European regulations, and between 0.03 ng/mL and 0.39 ng/mL for the ethoxylates. In influent wastewater, these limits were slightly higher. The total run time of 5 min for the alkylphenols and 8 min for the ethoxylates ensured high throughput. The developed method was applied to determine 4-t-OP and 4-NP and their mono- and di-ethoxylates in wastewater from several tank truck cleaning companies, which was subjected to ozonation and/or biological treatment. It was demonstrated that ozonation was best applied after the biological treatment, since in this case, the biological treatment could degrade most of the biodegradable organic matter, after which ozone could react directly with the recalcitrant organic pollutants. In this case, the concentrations of the target compounds in the wastewater of the investigated company decreased below the legally allowed concentration of the European water legislation.
The aim of this study was to investigate the occurrence of endocrine disrupting compounds (EDCs) in bottled waters. The examined compounds were bisphenol A (BPA), nonylphenol (NP), tert-octylphenol ...(tOP), dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl)phthalate (DEHP) and di(n-octyl)phthalate (DNOP). The presence of EDCs in bottled waters under poor storage conditions was also investigated after exposure outdoors under realistic conditions for 15 and 30 days. EDCs were recovered after liquid–liquid extraction and determined by employing Gas Chromatography–Mass Spectrometry. Most of these compounds were detected in bottled water from different brands purchased from local market. Storage at outdoor conditions had no significant effect on the concentrations of the examined compounds. Only BPA occurred at higher concentrations in polycarbonate containers exhibited an increasing trend during exposure. The estimated exposure to EDCs via consumption of drinking water was very low.
Alkylphenol ethoxylates (APEs) have been used in several offshore oil and gas production applications including as emulsifiers in drilling mud formulations, which may have resulted in their disposal ...to sea. Despite concern over the endocrine disrupting potential of their alkylphenol (AP) degradation products, information on the presence of AP/APEs in marine sediments in the vicinity of oil and gas production facilities is scarce. This paper presents the occurrence of AP/APEs in marine sediment in North Sea oil and gas fields. The concentrations of octylphenol, nonylphenol and their ethoxylates near offshore installations were broadly comparable to, or higher than those of coastal and estuarine point source discharges. When compared to environmental assessment criteria, the NPCA Class V threshold values for octylphenol and nonylphenol were exceeded within 100 m and 500 m of infrastructure respectively, with higher concentrations of AP/APEs reported in fields that came online prior to 1986.
•Alkylphenols and alkylphenol ethoxylates are present in marine sediment surrounding oil and gas infrastructure•Concentrations of nonylphenol and octylphenol exceeded environmental threshold criteria up to 500 m from an installation•Higher concentrations of alkylphenols and alkylphenol ethoxylates were found at oil and gas fields that came online prior to 1986
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