Treatment of synthetic textile wastewater containing dye mixtures with microcosms

The aim was to assess the ability of microcosms (laboratory-scale shallow ponds) as a post polishing stage for the remediation of artificial textile wastewater comprising two commercial dyes (basic red 46 (BR46) and reactive blue 198 (RB198)) as a mixture. The objectives were to evaluate the impact of Lemna minor L. (common duckweed) on the water quality outflows; the elimination of dye mixtures, organic matter, and nutrients; and the impact of synthetic textile wastewater comprising dye mixtures on the L. minor plant growth. Three mixtures were prepared providing a total dye concentration of 10 mg/l. Findings showed that the planted simulated ponds possess a significant (p < 0.05) potential for improving the outflow characteristics and eliminate dyes, ammonium-nitrogen (NH4-N), and nitrate-nitrogen (NO3-N) in all mixtures compared with the corresponding unplanted ponds. The removal of mixed dyes in planted ponds was mainly due to phyto-transformation and adsorption of BR46 with complete aromatic amine mineralisation. For ponds containing 2 mg/l of RB198 and 8 mg/l of BR46, removals were around 53%, which was significantly higher than those for other mixtures: 5 mg/l of RB198 and 5 mg/l of BR46 and 8 mg/l of RB198 and 2 mg/l of BR46 achieved only 41 and 26% removals, respectively. Dye mixtures stopped the growth of L. minor, and the presence of artificial wastewater reduced their development

Decolorization and partial mineralization of a polyazo dye by Bacillus firmus immobilized within tubular polymeric gel

The degradation of C.I. Direct red 80, a polyazo dye, was investigated using Bacillus firmus immobilized by entrapment in tubular polymeric gel. This bacterial strain was able to completely decolorize 50 mg/L of C.I. Direct red 80 under anoxic conditions within 12 h and also degrade the reaction intermediates (aromatic amines) during the subsequent 12 h under aerobic conditions. The tubular gel harboring the immobilized cells consisted of anoxic and aerobic regions integrated in a single unit which was ideal for azo dye degradation studies. Results obtained show that effective dye decolorization (97.8%), chemical oxygen demand (COD) reduction (91.7%) and total aromatic amines removal were obtained in 15 h with the immobilized bacterial cell system whereas for the free cells, a hydraulic residence time of 24 h was required for an equivalent performance in a sequential anoxic and aerobic process. Repeated-batch experiments indicate the immobilized cells could decolorize C.I. Direct red 80 and reduce medium COD in five successive batch runs with enhanced activity obtained after each consecutive run, thus suggesting its stability and potential for repeated use in wastewater treatment. UV–visible spectrophotometry and HPLC analysis were used to confirm the partial mineralization of the dye. Data from this study could be used as a reference for the development of effective industrial scale biotechnological process for the removal of dyes and their metabolites in textile wastewater

Aluminum(III) triggered aggregation-induced emission of glutathione-capped copper nanoclusters as a fluorescent probe for creatinine

Glutathione-capped copper nanoclusters (CuNCs) are presented that display aggregation-induced emission (AIE). This feature was exploited for selective and sensitive quantification of creatinine (CRN) which is an important diagnostic parameter. In the presence of Al 3+ ions, such CuNCs rapidly aggregate, and this induces enhanced a red emission. The AIE nature of CuNCs was proven via TEM and fluorimetry. On addition of CRN, the coordination between CRN and Al 3+ ions led to the quenching of fluorescence due to weakening the AIE. The best fluorescence intensity was measured at excitation/emission peaks of 360/585 nm. Quenched fluorescence intensity showed a linear dependence on the concentrations of CRN in the range of 2.5�34 μgL �1 with a detection limit of 0.63 μgL �1 . The sensing mechanism of probe for CRN detection is discussed. The probe was applied to the determination of CRN in spiked human serum samples and gave satisfactory results. Figure not available: see fulltext.. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature

Application of molecularly imprinted polymers and dual-emission carbon dots hybrid for ratiometric determination of chloramphenicol in milk

Chloramphenicol (CLP) is a veterinary antibiotic that has been banned due to its severe side effects but it is still illegally used in animal husbandry. In this work, the fabrication of simple, fast-response and highly selective ratiometric probe for sensitive visual detection of CLP antibiotic at trace levels in both indoor and outdoor is reported. For the construction of the ratiometric fluorescence probe (mMIP@YBCDs), two kinds of different carbon dots with yellow emission (Y/CDs, 560 nm) and blue emission carbon dots (B/CDs, 440 nm) were used as target sensitive and as reference dyes respectively. Besides, molecularly imprinted mesoporous silica was used as a recognized part of the probe. Upon the addition of different concentrations of CLP, the fluorescence of Y/CDs was quenched significantly while the fluorescence intensity of B/CDs stayed constant which was accompanied by gradual fluorescence color change from yellow-to-blue. The ratiometric probe has a linear response in the range of 0.1�3 μgL�1 with a detection limit 0.035 μgL�1. The practicality of the ratiometric method was validated by the quantification of CLP in milk samples. © 2020 Elsevier Lt

A review on in vivo and in vitro nanotoxicological studies in plants: A headlight for future targets

Owing to the unique properties and useful applications in numerous fields, nanomaterials (NMs) received a great attention. The mass production of NMs has raised major concern for the environment. Recently, some altered growth patterns in plants have been reported due to the plant-NMs interactions. However, for NMs safe applications in agriculture and medicine, a comprehensive understanding of bio-nano interactions is crucial. The main goal of this review article is to summarize the results of the toxicological studies that have shown the in vitro and in vivo interactions of NMs with plants. The toxicity mechanisms are briefly discussed in plants as the defense mechanism works to overcome the stress caused by NMs implications. Indeed, the impact of NMs on plants varies significantly with many factors including physicochemical properties of NMs, culture media, and plant species. To investigate the impacts, dose metrics is an important analysis for assaying toxicity and is discussed in the present article to broadly open up different aspects of nanotoxicological investigations. To access reliable quantification and measurement in laboratories, standardized methodologies are crucial for precise dose delivery of NMs to plants during exposure. Altogether, the information is significant to researchers to describe restrictions and future perspectives. © 2020 The Author

Detection of penicillin G residues in milk based on dual-emission carbon dots and molecularly imprinted polymers.

Instant detection of antibiotic residues in dairy products has been remained a challenge. Current methods require careful samples storage and handling, skilled personnel, and expensive instrumentations. Herein, we report the preparation of a ratiometric fluorescent sensor that contains different colored Carbon dots (CDs) as dual fluorophores, and a mesoporous structured molecularly imprinted polymer as a receptor (B/YCDs@mMIP) for penicillin-G (PNG) detection in milk. Upon PNG addition, only the fluorescence of yellow emissive CDs was quenched due to analyte blockage, while that of the blue emissive CDs stayed almost constant, which led to an obvious change in the fluorescence color from the yellow to blue. A linear response in the range of 1-32 nM with a detection limit of 0.34 nM and excellent recognition specificity for PNG over its analogs were also observed. Comparing our sensor with its counterparts, it exhibited a promising potential in the in-situ PNG detection in milk

Detection of penicillin G residues in milk based on dual-emission carbon dots and molecularly imprinted polymers

Instant detection of antibiotic residues in dairy products has been remained a challenge. Current methods require careful samples storage and handling, skilled personnel, and expensive instrumentations. Herein, we report the preparation of a ratiometric fluorescent sensor that contains different colored Carbon dots (CDs) as dual fluorophores, and a mesoporous structured molecularly imprinted polymer as a receptor (B/YCDs@mMIP) for penicillin-G (PNG) detection in milk. Upon PNG addition, only the fluorescence of yellow emissive CDs was quenched due to analyte blockage, while that of the blue emissive CDs stayed almost constant, which led to an obvious change in the fluorescence color from the yellow to blue. A linear response in the range of 1�32 nM with a detection limit of 0.34 nM and excellent recognition specificity for PNG over its analogs were also observed. Comparing our sensor with its counterparts, it exhibited a promising potential in the in-situ PNG detection in milk. © 2020 Elsevier Lt

A review on in vivo and in vitro nanotoxicological studies in plants: A headlight for future targets

Owing to the unique properties and useful applications in numerous fields, nanomaterials (NMs) received a great attention. The mass production of NMs has raised major concern for the environment. Recently, some altered growth patterns in plants have been reported due to the plant-NMs interactions. However, for NMs safe applications in agriculture and medicine, a comprehensive understanding of bio-nano interactions is crucial. The main goal of this review article is to summarize the results of the toxicological studies that have shown the in vitro and in vivo interactions of NMs with plants. The toxicity mechanisms are briefly discussed in plants as the defense mechanism works to overcome the stress caused by NMs implications. Indeed, the impact of NMs on plants varies significantly with many factors including physicochemical properties of NMs, culture media, and plant species. To investigate the impacts, dose metrics is an important analysis for assaying toxicity and is discussed in the present article to broadly open up different aspects of nanotoxicological investigations. To access reliable quantification and measurement in laboratories, standardized methodologies are crucial for precise dose delivery of NMs to plants during exposure. Altogether, the information is significant to researchers to describe restrictions and future perspectives. © 2020 The Author

Dual-colored carbon dot encapsulated metal-organic framework for ratiometric detection of glutathione

A dual-emissive metal−organic frameworks was prepared by encapsulating yellow emitting and blue emitting carbon dots into the zeolitic imidazolate framework (BYCDs@ZIF-8) which acted as a ratiometric probe for Glutathione. The composite shows dual-emissions which are centered at 565 and 440 nm under a single excitation wavelength of 365 nm. In the presence of Cu2+, the fluorescence of yellow emitting carbon dots in the nanocomposite was selectively enhanced, while the fluorescence of the blue emitting carbon dots was quenched. Upon addition of glutathione on Cu2+- BYCDs@ZIF-8 system, the fluorescence of both carbon dots gradually restored to their original amounts due to the strong interaction between glutathione and Cu2+. Detection progress can be observed by unaided eyes with a visual color change from yellow to blue under ultraviolet irradiation. Under the optimal conditions, glutathione determined in the range of 3–25 nM with a limit of detection of 0.90 nM (Signal/Noise = 3). The employed composite with distinct size-selectivity not only decreases the background interference from large molecule but it is also able to strongly accumulate the target analytes and thus greatly amplifies the sensing signal and specificity. Also, the ratiometric strategy provided built-in self-calibration for signal correction and improved precision and accuracy. This method was applied for the detection of glutathione in fruit samples and showed satisfactory results. © 2019 Elsevier B.V