Material synthesis requires an enormous amount of organic solvents which leads to huge environmental burdens. Being so, the necessity to utilize non-toxic chemicals is of growing interest in the global market. Harnessing a green fabrication strategy could be a sustainable remedy. Herein, life cycle assessment (LCA) and techno-economic assessment (TEA) using a cradle-to-gate approach to select the green synthesis route for the production of main components in mixed matrix membranes such as polymer and fillers were studied. Five representative synthesis routes of polymers of intrinsic microporosity (PIM-1) and fillers such as UiO-66-NH2 (UiO: University of Oslo) were conducted. Our findings revealed that the tetrachloroterephthalonitrile (TCTPN) synthesized PIM-1 using a novel approach (e.g., P5-Novel synthesis) and solvent-free synthesized UiO-66-NH2 (e.g., U5-Solvent-free) demonstrated the least environmental impact and are most economically feasible. The environmental burden and cost of PIM-1 synthesized by P5-Novel synthesis route decreased by 50 % and 15 %, respectively, while that of UiO-66-NH2 produced via U5-Solvent-free route reduced by 89 % and 52 %, respectively. Additionally, solvent reduction was found to have an apparent effect on cost-saving, whereby the production cost declined 13 % with a 30 % solvent reduction. Alleviation of environmental burdens could also be found through recovering solvents or substituting with a greener alternative (e.g., water). The fundamentals gained on the environmental impacts and economic feasibility of PIM-1 and UiO-66-NH2 production from this LCA-TEA study may provide a preliminary evaluation for the development of green and sustainable materials.
The rate of conversion of 1 to N-(2-methoxyphenyl)phthalimide (2) within [HCl] range 5.0x10(-3)-1.0 M at 1.0M ionic strength (by NaCl) reveals the presence of both uncatalyzed and specific acid-catalyzed kinetic terms in the rate law. Intramolecular carboxamide group-assisted cleavage of amide bond of 1 reveals rate enhancement of much larger than 10(6)-fold compared to the expected rate of analogous intermolecular reaction.
Correction for 'Functionalized fluorescent terephthalate monomers and their attempted polyester formation' by Yvonne S. L. Choo et al., Org. Biomol. Chem., 2020, 18, 8735-8745, DOI: 10.1039/D0OB01533D.
Four porous coordination networks have been synthesized from 1,4-benzenedicarboxylate with Cl, Br, I, and NO2 substituents whose different spatial differences are sufficient to influence the coordination mode of adjacent carboxyl moieties to unlock an inter-penetrating framework to give isostructural structures. Their size and polarity differences account for the diverging CO2 adsorption performances.
The rate of aqueous cleavage of N-(2’-hydroxyphenyl)phthalimide (A), monitored at 320 nm, 1.0 10–3 M NaOH, 35ºC and within CH3CN content range 1% – 80% v/v in mixed aqueous solvents, follows the reaction scheme: A + HO-/H2O ➝ B + HO-/H2O ➝ P1 + P2 where B, P1 and P2 represent N-(2’-hydroxyphenyl)phthalamic acid, phthalic acid and 2-hydroxyaniline, respectively. The values of k1 and k2 at different content of CH3CN have been calculated from a kinetic equation based upon a reaction scheme with two irreversible pseudo-first-order consecutive reaction paths. The values of k1/k2 are > 104 within CH3CN content range 1% – 80% v/v in mixed aqueous solvents. The intermediate hydrolysis product (B) exists in 72% dianionic, 27.9% monoanionic and 0.1% nonionic form under the present experimental conditions. Both dianionic and monoanionic forms of B are non-reactive while the nonionic form of B is reactive towards hydrolysis under such conditions.
Phthalates have been blended in various compositions as plasticizers worldwide for a variety of purposes. Consequently, humans are exposed to a wide spectrum of phthalates that needs to be researched and understood correctly. The goal of this review is to focus on phthalate's internal exposure pathways and possible role of human digestion on liver toxicity. In addition, special focus was made on stem cell therapy in reverting liver toxicity. The known entry of higher molecular weight phthalates is through ingestion while inhalation and dermal pathways are for lower molecular weight phthalates. In human body, certain phthalates are digested through phase 1 (hydrolysis, oxidation) and phase 2 (conjugation) metabolic processes. The phthalates that are made bioavailable through digestion enter the blood stream and reach the liver for further detoxification, and these are excreted via urine and/or feces. Bis(2-ethylhexyl) phthalate (DEHP) is a compound well studied involving human metabolism. Liver plays a pivotal role in humans for detoxification of pollutants. Thus, continuous exposure to phthalates in humans may lead to inhibition of liver detoxifying enzymes and may result in liver dysfunction. The potential of stem cell therapy addressed herewith will revert liver dysfunction and lead to restoration of liver function properly.
The apparent second-order rate constant (k OH) for hydroxide-ion-catalyzed conversion of 1 to N-(2'-methoxyphenyl)phthalamate (4) is approximately 10(3)-fold larger than k OH for alkaline hydrolysis of N-morpholinobenzamide (2). These results are explained in terms of the reaction scheme 1 --> k(1obs) 3 --> k(2obs) 4 where 3 represents N-(2'-methoxyphenyl)phthalimide and the values of k(2obs)/k(1obs) vary from 6.0 x 10(2) to 17 x 10(2) within [NaOH] range of 5.0 x 10(-3) to 2.0 M. Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 1 decrease from 21.7 x 10(-3) to 15.6 x 10(-3) s(-1) with an increase in ionic strength (by NaCl) from 0.5 to 2.5 M at 0.5 M NaOH and 35 degrees C. The values of k obs, obtained for alkaline hydrolysis of 2 within [NaOH] range 1.0 x 10(-2) to 2.0 M at 35 degrees C, follow the relationship k(obs) = kOH[HO(-)] + kOH'[HO (-)] (2) with least-squares calculated values of kOH and kOH' as (6.38 +/- 0.15) x 10(-5) and (4.59 +/- 0.09) x 10(-5) M (-2) s(-1), respectively. A few kinetic runs for aqueous cleavage of 1, N'-morpholino-N-(2'-methoxyphenyl)-5-nitrophthalamide (5) and N'-morpholino-N-(2'-methoxyphenyl)-4-nitrophthalamide (6) at 35 degrees C and 0.05 M NaOH as well as 0.05 M NaOD reveal the solvent deuterium kinetic isotope effect (= k(obs) (H 2) (O)/ k(obs) (D 2 ) (O)) as 1.6 for 1, 1.9 for 5, and 1.8 for 6. Product characterization study on the cleavage of 5, 6, and N-(2'-methoxyphenyl)-4-nitrophthalimide (7) at 0.5 M NaOD in D2O solvent shows the imide-intermediate mechanism as the exclusive mechanism.
This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics.
The reaction of diethyl 2,5-bis(tert-butyl)phenoxy-3,6-dihydroxyterephthalate (1) with tetraethylene glycol di(p-toluenesulfonate) under high-dilution conditions afforded several isolated products. Two products were identified as macrocycles with one being the 1 + 1 crown ether derivative 3 (10% yield), and the second being the 2 + 2 crown ether compound D3 (19% yield). The X-ray structure for 3 was determined with the asymmetric unit observed to comprise half of the molecule. The small crown ether ring of 3 interacts with K+ or H+ ions in MeOH, but binding is weak and the macrocyclic cavity is too small to fully encapsulate the K+ ion. Transesterification of compounds 1, its methylated version 2 and 3 with diols such as ethylene glycol or 1,4-butandiol produced monomers (M1-M3) which were reacted with terephthaloyl chloride. Short oligomers were produced (PolyM1-PolyM3) rather than extensive polymeric materials and all displayed solid state fluorescence. The absorption and fluorescence properties of M1-M2 and their polymers can be related to subtle structural changes. The Stokes shift for M2 of 15 627 cm-1 in DCM is one of the largest observed for a simple organic chromophore in fluid solution.
In the present paper, the potentiality of integrating microbial fuel cells (MFCs) with a photocatalytic reactor to maximize the wastewater treatment efficiency with concurrent power generation was explored. Dimethyl phthalate (DMP) and acetic acid (AA) were the employed substrate and the co-substrate, respectively, using Pseudomonas aeruginosa as a biocatalyst. MFCs operated by single substrate showed the maximum power generation of 0.75-3.84 W m-3 whereas an addition of AA as the co-substrate yielded 3-12 fold higher power generation. Pseudomonas aeruginosa produced phenazine-1-carboxylic acid in DMP-fed MFC as the metabolite whereas AA along with DMP yielded pyocyanin which reduced the charge transfer resistance. Chemical oxygen demand (COD) removal efficiency in the MFCs was circa 62% after 11 days of operation. Thereafter, it further increased albeit with a drastic reduction in power generation. Subsequently, the MFC anolyte was treated in a photocatalytic reactor under visible light irradiation and catalyzed by CuO-gC3N4. The performance of photocatalytic reactor was evaluated, with COD and total organic carbon (TOC) removal efficiency of 88% and 86% after 200 min of light irradiation. The present work suggests that the MFC can be integrated with photocatalysis as a sustainable wastewater treatment method with concurrent power generation.
Postconsumer polyethylene terephthalate (PET) has potential applications in many areas of manufacturing, but contamination by hazardous polyvinyl chloride (PVC) in common waste streams can reduce its recyclable value. Separating collected PET-PVC mixtures before recycling remains very challenging because of the similar physicochemical properties of PET and PVC. Herein, we describe a novel flotation process with corona modification pretreatment to facilitate the separation of PET-PVC mixtures. Through water contact angle, surface free energy, X-ray photoelectron and FT-IR characterization, we found that polar hydroxyl groups can be more easily introduced on the PVC surface than on the PET surface induced by corona modification. This selective wetting can suppress the floatability of PVC, leading to the separation of PET as floating product. A reliable mechanism including two different hydrogen-abstraction pathways was established. Response surface methodology consisting of Plackett-Burman and Box-Behnken designs was adopted for optimization of the combined process, and control parameters were solved based on high-quality prediction models, with fitting from significant variables and interactions. For physical or chemical circulation strategies with PET purity prioritization, the validated purity of the product reached 96.05% at a 626 W corona power, 5.42 m/min passing speed, 24.78 mg/L frother concentration and 286 L/h air flow rate. For the energy recuperation strategy with PET recovery prioritization, the factual recovery reached 98.08% under a 601 W corona power, 6.04 m/min passing speed, 27.55 mg/L frother concentration and 184 L/h air flow rate. The current work provides technological insights into the cleaner disposal of waste plastics.
Due to environmental concern, the research to date has tended to focus on how textile dye removal can be carried out in a greener manner. Therefore, this study aims to evaluate the decolorization and biotransformation pathway of Mordant Orange-1 (MO-1) by Cylindrocephalum aurelium RY06 (C. aurelium RY06). Decolorization study was conducted in a batch experiment including the investigation of the effects of physio-chemical parameters. Enzymatic activity of C. aurelium RY06 during the decolorization was also investigated. Moreover, transformation and biodegradation of MO-1 by C. aurelium RY06 were observed using the gas chromatography-mass spectrometry. Manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase, and 2,3-dioxygenase enzymes were detected during the decolorization. In general, the present work concluded that the MO-1 was successfully degraded by C. aurelium RY06 and transformed to be maleic acid and to be isophtalic acid.
This study investigated the removal of parabens, N,N-diethyl-m-toluamide (DEET), and phthalates by ozonation. The second-order rate constants for the reaction between selected compounds with ozone at pH 7 were of (2.2 +/-0.2) X 10(6) to (2.9 +/-0.3) X 10(6) M 1/s for parabens, (2.1+/- 0.3) to (3.9 +/-0.5) M-1/s for phthalates, and (5.2 +/-0.3) M-1/s for DEET. The rate constants for the reaction between selected compounds with hydroxyl radical ranged from (2.49 +/-0.06) x 10(9) to (8.5 +/-0.2) x 10(9) M-1/s. Ozonation of selected compounds in secondary wastewater and surface waters revealed that ozone dose of 1 and 3 mg/L yielded greater than 99% depletion of parabens and greater than 92% DEET and phthalates, respectively. In addition, parabens were found to transform almost exclusively through the reaction with ozone, while DEET and phthalates were transformed almost entirely by hydroxyl radicals (.OH).
Shaped-controlled ZnO architectures including spherical, rod, rice-like and flower-like were fabricated via a reflux method in which the morphology, crystallinity, functional group and optical properties were tailored under different pH values in the precursor solution. The photoactivities of the prepared ZnO were evaluated under UV irradiation and the findings implied that the flower-like ZnO synthesized at pH 12 displayed superior activities on palm oil mil effluent degradation than those of other structures. The photocatalytic enhancement of flower-like ZnO was ascribed to its unique architecture, good crystallinity and superior optical properties. The flower-like ZnO with excellent photocatalytic performance have been confirmed by formation of hydroxyl radicals using a terephthalic acid-photoluminescence test. There was an optimal photocatalyst amount of 1.0 g/L, at which a maximum chemical oxygen demand removal of palm oil mill effluent was achieved under exposure of UV light. The phytotoxicity experiment via mung beans demonstrated a decrease in phytotoxicity.
Cadmium (Cd) and Lead (Pb) from industrial wastewater can bioaccumulate in the living organisms of water bodies, posing serious threats to human health. Therefore, efficient remediation of heavy metal ions of Cd (II) and Pb (II) in aqueous media is necessary for public health and environmental sustainability. In the present study, water stable Zirconium (Zr) based metal organic frameworks (MOFs) with SO3H functionalization were synthesized by solvothermal method and used first time for the adsorption of Cd (II) and Pb (II). Synthesis of UiO-66-SO3H, nano-sized (<100 nm) MOFs, was confirmed by FTIR, XRD, FESEM and BET. Effects of contact time, pH and temperature were investigated for adsorption of Cd (II) and Pb (II) onto SO3H-functionalized Zr-MOFs. The UiO-66-SO3H displayed notable rejections of 97% and 88% towards Cd (II) and Pb (II), respectively, after 160 min at 25 °C and pH (6) with an initial concentration of 1000 mg/L. Adsorption capacities of Cd (II) and Pb (II) were achieved as 194.9154 (mg/g) and 176.6879 (mg/g), respectively, at an initial concentration of 1000 mg/L. The Pseudo second-order kinetic model fitted well with linear regression (R2) of value 1. The mechanism was confirmed mainly as a chemisorption and coordination interaction between sulfone group (-SO3H) and metal ions Cd (IIa) and Pb (II). These results may support effective adsorption and can be studied further to enrich and recycle other heavy metals from wastewater.
The occurrence of 14 phthalate metabolites was found in human urine samples collected from seven Asian countries: China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam. Phthalate metabolites were found in all samples, indicating widespread exposure of humans to phthalates in these Asian countries. The highest total (the sum of 14 phthalates) phthalate metabolite concentrations were found in samples collected from Kuwait (median: 1050 ng/mL), followed in decreasing order by samples from India (389 ng/mL), China (234 ng/mL), Vietnam (133 ng/mL), Japan (120 ng/mL), Korea (117 ng/mL), and Malaysia (94.9 ng/mL). The creatinine-adjusted median concentrations of total phthalates for urine samples from Kuwait, India, China, Vietnam, Japan, Korea, and Malaysia were 692, 506, 289, 119, 103, 104, and 169 μg/g creatinine, respectively. Monomethyl phthalate (mMP), monoethyl phthalate (mEP), mono (2-isobutyl phthalate) (miBP), mono-n-butyl phthalate (mBP), and metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the dominant compounds, collectively accounting for >95% of the total concentrations in the samples from the seven countries. The profiles of urinary phthalate metabolite concentrations varied among the samples collected from the seven countries. Urine samples from Kuwait contained the highest concentrations of mEP (median: 391 ng/mL), mBP (94.1 ng/mL), and the metabolites of DEHP (202 ng/mL), whereas samples from China and Japan contained the highest concentrations of miBP (50.8 ng/mL) and mMP (17.5 ng/mL), respectively. mEP was the predominant metabolite in urine samples from India and Kuwait (accounting for 49% of the total), mBP and miBP were the predominant compounds in samples from China (52%), and DEHP metabolites were the predominant compounds in samples from Korea (46%) and Vietnam (52%). Based on the urinary concentrations of mEP, mBP, miBP, and DEHP metabolites of the samples from the seven Asian countries, we estimated daily intake rates of diethyl phthalate (DEP), dibutyl phthalate (DBP), and DEHP. The results indicated that people in the seven Asian countries are exposed to DEP, DBP, and DEHP at levels well below the reference doses (RfD) suggested as unsafe by the U.S. Environmental Protection Agency (EPA). The estimated exposure doses to DEHP in Kuwait, however, were above the RfD recommended by the EPA.
Immobilization can be used to improve the stability of lipases and enhances lipase recovery and reusability, which increases its commercial value and industrial applications. Nevertheless, immobilization frequently causes conformational changes of the lipases, which decrease lipase catalytic activity. in the present work, we synthesized UIO-66 and grafted UIO-66 crystals with proline for immobilization of Candida rugosa lipase (CRL). As indicated by steady-state fluorescence microscopy, grafting of proline onto UIO-66 crystals induced beneficial conformational change in CRL. CRL immobilized on UIO-66/Pro (CRL@UIO-66/Pro) demonstrated higher enzyme activity and better recyclability than that immobilized on UIO-66 (CRL@UIO-66) in both hydrolysis (CRL@UIO-66/Pro: 0.34 U; CRL@UIO-66: 0.15 U) and transesterification (CRL@UIO-66/Pro: 0.93 U; CRL@UIO-66: 0.25 U) reactions. The higher values of kcat and kcat/Km of CRL@UIO-66/Pro also showed that it had better catalytic efficiency as compared to CRL@UIO-66. It is also worth noting that CRL@UIO-66/Pro (0.93 U) demonstrated a much higher transesterification activity as compared to free CRL (0.11 U), indicating that UIO-66/Pro has increased the solvent stability of CRL. Both CRL@UIO-66 and CRL@UIO-66/Pro were also used for the fabrication of biosensors for nitrofen with a wide linear range (0-100 μM), lower limit of detection, and good recovery rate.
Despite the ubiquity of microplastics (MPs) in aquatic environments and their proven ability to carry a wide variety of chemicals, very little is known about the impacts of virgin or contaminant-loaded MPs on organisms. The primary aim of this study was to investigate the impacts of virgin or phenanthrene (Phe)-loaded low-density polyethylene (LDPE) fragments on a suite of biomarker responses in juvenile African catfish (Clarias gariepinus). Virgin LDPE (50 or 500µg/L) were preloaded with one of two nominal Phe concentrations (10 or 100µg/L) and were exposed to the fish for 96h. Our findings showed one or both Phe treatments significantly increased the degree of tissue change (DTC) in the liver while decreased the transcription levels of forkhead box L2 (foxl2) and tryptophan hydroxylase2 (tph2) in the brain of C. gariepinus. Exposure to either levels of virgin MPs increased the DTC in the liver and plasma albumin: globulin ratio while decreased the transcription levels of tph2. Moreover, MPs modulated (interacted with) the impact of Phe on the DTC in the gill, plasma concentrations of cholesterol, high-density lipoprotein (HDL), total protein (TP), albumin, and globulin, and the transcription levels of fushi tarazu-factor 1 (ftz-f1), gonadotropin-releasing hormone (GnRH), 11 β-hydroxysteroid dehydrogenase type 2 (11β-hsd2), and liver glycogen stores. Results of this study highlight the ability of virgin LDPE fragments to cause toxicity and to modulate the adverse impacts of Phe in C. gariepinus. Due to the wide distribution of MPs and other classes of contaminants in aquatic environments, further studies are urgently needed to elucidate the toxicity of virgin or contaminant-loaded MPs on organisms.