Crewspoole9196

A kind of nitrogen doped carbon dots (N-CDs) was facilely fabricated from polyethyleneimine and anhydrous citric acid, and which was adopted to develop a neoteric "on-off" and "off-on" fluorescent sensor for rapidly and efficiently sensing Hg2+ and I-. The fluorescence of N-CDs was notably quenched (off) in the existence of Hg2+ derived from strong interaction and the electron transfer between N-CDs and Hg2+, while the quenched fluorescence of the N-CDs and Hg2+ system was strikingly regained by addition of I- (on) resulted from the separation of N-CDs and Hg2+ due to the higher binding preference between Hg2+ and I-. Under optimal conditions, the linear detection ranges were 0.01-20 μM for Hg2+ and 0.025-7 μM for I-, respectively. Meanwhile, the detection limits could be down to 3.3 nM for Hg2+ and 8.5 nM for I-, respectively. Satisfied recoveries had also been gained for measuring Hg2+ and I- in practical water samples. The constructed "on-off-on" fluorescent sensor provided a simple, rapid, robust and reliable platform for detecting Hg2+ and I- in environmental applications.The WHO AQGs 2021 incorporates more stringent guidelines for air pollution, which now include both ambient and indoor air quality. We discuss the challenges to meeting the AQGs for indoor air. We suggest a cocktail-like treatment solution that combines efforts from a multidiscipline field of policy, technology, and education.Proteins fluctuate between different conformations in solution, and these conformational fluctuations can be important for protein function and allosteric regulation. The chorismate mutase from Saccharomyces cerevisiae (ScCM), a key enzyme in the biosynthesis of aromatic amino acids, is allosterically activated and inhibited by tryptophan and tyrosine, respectively. It was initially proposed that in the absence of effector, ScCM fluctuates between activated R and inhibited T conformations according to the Monod-Wyman-Changeux (MWC) model, although a more complex regulation pattern was later suggested by mutagenesis and kinetic data. Here we used NMR relaxation dispersion experiments to understand the conformational fluctuations on the microsecond-to-millisecond timescale that occur in ScCM. In the absence of allosteric effectors, ScCM did not exclusively exchange between T and R conformations, suggesting that the two-state MWC model is insufficient to explain conformational dynamics. Addition of tyrosine led to the quenching of much of the motion on this timescale, while new motions were identified in the presence of tryptophan. These new motions are consistent with conformational fluctuations into an alternative conformation that may be important for enzyme activity.Pharmaceuticals residual in the human urine are difficult to remove in the conventional wastewater treatment plants (WWTPs) and cause a serious environmental issue. Hence, we developed a FeOCl-coated ceramic membrane coupled with the Photo-Fenton system for direct removing pharmaceuticals from human urine. In this study, the removal efficiency of CBZ from hydrolyzed urine was higher than that from fresh urine. The apparent rate constant (kobs) of CBZ from hydrolyzed urine could reach 0.0163 min-1, 1.39 times higher than that from fresh urine (0.0117 min-1). Interestingly, this performance was not caused by the solution pH. The effect of substrates in the hydrolyzed urine was further explored, verifying that ammonia played a key role in quenching the hydroxyl radicals (•OH). The nitrogen reactive species (RNS) were then generated, resulting in that the kobs of CBZ from hydrolyzed urine sharply decreased, compared with the phosphate buffer solution (pH = 9). The quenching experiment was further to confirm that the RNS was primary reactive oxide species in the hydrolyzed urine. Based on the data of kinetic study and reported previously, competitive kinetic modeling was set up, which could successfully predict the removal efficiency of pharmaceuticals from hydrolyzed urine. The study provided a new method for removing pharmaceuticals residual in human urine and the kinetic modeling could be widely used to predict the removal of pharmaceuticals from human urine.The bioconcentration of dimethyl phthalate (DMP) diethyl phthalate (DEP) dibutyl phthalate (DBP) butyl benzyl phthalate (BBzP), di-(2-ethy hexyl) phthalates (DEHP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-(2-ethy hexyl) phthalate (MEHP) in the soft corals Coelogorgia palmosa, Sinularia sp., Sarcophyton glaucum, and Lobophytum sp. was investigated. Specimens were cultured in a microcosm environment built-up at the Genova Aquarium and analyses were carried out by in vivo SPME-LC-MS/MS. The distributions of the phthalates among the four surveyed species resulted significantly different. Calculated bioconcentration factors (BCFs) showed values spanning over two orders of magnitude, from a minimum of log10 BCFDEP = 1.0 in Sarcophyton glaucum to a maximum of log10 BCFDBP = 3,9 calculated for Coelogorgia palmosa. Moreover, the calculated BCFs of the long chain phthalates resulted up to three orders of magnitude lower than theoretically predicted (from logKow), whereas BCF of short chain phthalates resulted higher. This, together with the detection of phthalic acid monoesters, suggests the presence of species-specific different metabolic transformation among the surveyed soft coral species that involve DEHP.The feasibilities of the anaerobic co-digestion of two of the most relevant biowastes, food waste and garden and park waste, were evaluated and compared with the hydrothermal treatment of each waste and the anaerobic co-digestion of raw biowastes with the process water generated. The effects on the process stability and energy recovery were also analyzed. Anaerobic digestion was the best option for food waste treatment from an energetic point of view, with 81% recovery of the energy stored in the feedstock, while the highest energy recovery from garden and park waste was obtained for the solid fraction generated from hydrothermal treatment (85.5%). In addition, the anaerobic co-digestion of food waste with 5% of the process water generated from garden and park waste showed a similar energy recovery to that of food waste only (∼80%), thus improving the biological stability of the process.In solar photocatalysis, light utilization and recycling of powder from reaction solution are the main obstructions that hinder the photocatalytic efficacy of any photocatalyst. In this respect, a floatable system is effective for efficient solar photocatalysis by light utilization. Due to the maximum solar light absorption property, floating nanocomposite photocatalyst is an appealing substitute for effective wastewater treatment. Floating photocatalysts are a non-oxygenated and non-stirred solution that is a good light harvester, stable, non-toxic, biodegradable, naturally abundant in nature. They also have low density, a simple preparation process, no need to stir, and high porosity. Due to these characteristics, floating photocatalysts are widely favored and ideal candidates for practical environmental remediation. Several researchers have come up with new and innovative ways for immobilizing capable photocatalyst on a floatable substrate to produce floating nanocomposite photocatalytic material. In recent decades, g-C3N4-based floating photocatalysts have gained a lot of attention as g-C3N4 is a visible light active photocatalyst with unique and exceptional properties. It also has good photocatalytic activity in waste water treatment and environmental remediation. Many previous reports have studied the logical design and manufacturing method for heterojunction floating photocatalysts and immobilized floating photocatalysts. Based on those studies, we have focused on the g-C3N4 based immobilized and non-immobilized floating photocatalysts for pollutant degradation. We have also categorized immobilized floating photocatalyst based on several lightweight substrates such as expanded perlite and glass microbead. In addition, future challenges have been discussed to maximize solar light absorption and to improve the efficiency of broadband response floating photocatalysts. Floating photocatalysis is an advanced technique in energy conversion and environmental remediation thus requires special consideration.The research investigated a novel strategy that can synchronously remove Ni2+ and Cu2+ by synthesizing amyloid fibrils under harsh conditions. The adsorption capacity of Ni2+ and Cu2+ increased by 18.5% and 34.1% respectively in the in-situ scenario as compared to that Ni2+ and Cu2+ were introduced after amyloid fibrils preparation, meantime, it avoids the generation of acidic waste liquid in the process of preparing amyloid fibrils. The adsorption behaviors of Ni2+ and Cu2+ can be well described by the pseudo-second-order kinetic model and Langmuir isotherm. The functional groups of amide, hydroxyl, and carboxyl played determining roles in the adsorption process. Moreover, when the amyloid fibrils were prepared in the presence of Ni2+ and Cu2+, i.e., the in-situ adsorption scenario, metal ions tended to occupy the functional sites, inhibit protein aggregation, and affect long amyloid fibrils synthesis accordingly. Metal ion-binding site prediction server was used to predict the binding sites of metal ions towards the protein sequence within amyloid fibrils, and the metal ion was observed to preferentially bind to a particular residue such as glutamic acid, cysteine, and serine. The amyloid fibrils be potentially valuable for the removal of heavy metals in strongly acidic wastewater such as acidic mining drainage.The efficiency of oxidative species generation is one of the crucial parameters for the application of any system based on advanced oxidation processes (AOPs). This paper presents an approach to the correct determination of quantum yields of the hydroxyl radical upon UV photolysis of natural Fe(III) carboxylates, which are widely used in the works devoted to Environmental Chemistry and Water Treatment. The approach is based on the use of [FeOH]2+ hydroxocomplex as a reference system with the well-known quantum yield of hydroxyl radical and benzene as a selective trap for the •OH radical. For the first time, the quantum yields of the •OH radical have been determined for the most popular Fe(III) oxalate photosystem in the wide range of initial parameters (pH, excitation wavelength, concentration of oxalate and Fe(III) ions). Also the oxidation potential of Fe(III) oxalate photosystem was tested on a set of persistent organic herbicides, and quantum yields of the photodegradation of herbicides were compared with the quantum yield of the •OH radical. The Fe(III) oxalate photosystem is recommended as a suitable system for the generation of •OH radical at neutral pH under UV radiation.Organic dye and antibiotic residues are some of the key substances that can contaminate the environment due to their wide usage in various industries and modern medicine. The degradation of these substances present in waterbodies is essential while contemplating human health. N6-methyladenosine cell line Photocatalysts (PSs) are promising materials that develop highly reactive species instantly by simple solar energy conversion for degrading the organic dye and antibiotic residues and converting them into nontoxic products. Among numerous semiconductors, the bismuth (Bi)-containing PS has received great attention due to its strong sunlight absorption, facile preparation, and high photostability. Owing to the technology advancement and demerits of the traditional methods, a Bi-containing direct Z-scheme PS has been developed for efficient photogenerated charge carrier separation and strong redox proficiency. In this review, a synthetic Bi-based Z-scheme heterojunction that mimics natural photosynthesis is described, and its design, fabrication methods, and applications are comprehensively reviewed.