Ozonation of trace organic compounds in different municipal and industrial wastewaters : kinetic-based prediction of removal efficiency and ozone dose requirements

For the wide application of ozonation in (industrial and municipal) wastewater treatment, prediction of trace organic compounds (TrOCs) removal and evaluation of energy requirements are essential for its design and operation. In this study, a kinetics approach, based on the correlation between the second order reaction rate constants of TrOCs with ozone and hydroxyl radicals ((OH)-O-center dot) and the ozone and (OH)-O-center dot exposure (i.e., integral (sic)O-3(sic)dt and integral [(OH)-O-center dot]dt, which are defined as the time integral concentration of O-3 and (OH)-O-center dot for a given reaction time), was validated to predict the elimination efficiency in not only municipal wastewaters but also industrial wastewaters. Two municipal wastewater treatment plant effluents from Belgium (HB-effluent) and China (QG-effluent) and two industrial wastewater treatment plant effluents respectively from a China printing and dyeing factory (PD-effluent) and a China lithium-ion battery factory (LZ-effluent) were used for this purpose. The (OH)-O-center dot scavenging rate from the major scavengers (namely alkalinity, effluent organic matter (EfOM) and NO2-) and the total (OH)-O-center dot scavenging rate of each effluent were calculated. The various water matrices and the (OH)-O-center dot scavenging rates resulted in a difference in the requirement for ozone dose and energy for the same level of TrOCs elimination. For example, for more than 90% atrazine (ATZ) abatement in HB-effluent (with a total (OH)-O-center dot scavenging rate of 1.9 x 10(5) s(-1)) the energy requirement was 12.3 x 10(-2) kWh/m(3), which was lower than 30.1 x 10(-2) kWh/m(3) for PD-effluent (with the highest total (OH)-O-center dot scavenging rate of 4.7 x 10(5) s(-1)). Even though the water characteristics of selected wastewater effluents are quite different, the results of measured and predicted TrOCs abatement efficiency demonstrate that the kinetics approach is applicability for the prediction of target TrOCs elimination by ozonation in both municipal and industrial wastewater treatment plant effluents

The potential mechanisms and application prospects of non-coding RNAs in intervertebral disc degeneration

Low back pain (LBP) is one of the most common musculoskeletal symptoms and severely affects patient quality of life. The majority of people may suffer from LBP during their life-span, which leading to huge economic burdens to family and society. According to the series of the previous studies, intervertebral disc degeneration (IDD) is considered as the major contributor resulting in LBP. Furthermore, non-coding RNAs (ncRNAs), mainly including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), can regulate diverse cellular processes, which have been found to play pivotal roles in the development of IDD. However, the potential mechanisms of action for ncRNAs in the processes of IDD are still completely unrevealed. Therefore, it is challenging to consider ncRNAs to be used as the potential therapeutic targets for IDD. In this paper, we reviewed the current research progress and findings on ncRNAs in IDD: i). ncRNAs mainly participate in the process of IDD through regulating apoptosis of nucleus pulposus (NP) cells, metabolism of extracellular matrix (ECM) and inflammatory response; ii). the roles of miRNAs/lncRNAs/circRNAs are cross-talk in IDD development, which is similar to the network and can modulate each other; iii). ncRNAs have been attempted to combat the degenerative processes and may be promising as an efficient bio-therapeutic strategy in the future. Hence, this review systematically summarizes the principal pathomechanisms of IDD and shed light on the therapeutic potentials of ncRNAs in IDD

Soliton microcombs in whispering gallery mode crystalline resonators with dispersive intermode interactions

Soliton microcombs have shown great potential in a variety of applications ranging from chip scale frequency metrology to optical communications and photonic data center, in which light coupling among cavity transverse modes, termed as intermode interactions, are long-existing and usually give rise to localized impacts on the soliton state. Of particular interest are whispering gallery mode based crystalline resonators, which with dense mode families, potentially feature interactions of all kind. While effects of narrow-band interactions such as spectral power spikes have been well recognized in crystalline resonators, that of broadband interactions remains unexplored. Here, we demonstrate soliton microcombs with broadband and dispersive intermode interactions, in home-developed magnesium fluoride microresonators with an intrinsic $\mathbf{Q}$-factor approaching 10 billion. Soliton combs with broadband spectral tailoring effect have been observed. Remarkably, footprints of both constructive and destructive interference on solitons have been observed, which as confirmed by simulations, are connected to the dispersive effects of the coupled mode family. The ultra-high-Q magnesium fluoride microresonator could also support high efficient soliton microcomb via intermode interactions, as well as rich Raman lasing dynamics. Our results not only contribute to the understanding of dissipative soliton dynamics in multi-mode or coupled resonator systems, but also extend the access to stable soliton combs in crystalline microresonators where mode control and dispersion engineering are usually challenging

Removal of nitrogen components, bulk organics, and fluorophores during one-stage partial nitrification-Anammox treatment of landfill leachate

Anammox-based processes have been intensively studied for the nitrogen removal from leachate, but less attention was paid to monitoring the evolution of leachate organics. In this study, fluorescence Excitation-Emission Matrix (EEM) measurement coupling with Parallel Factor Analysis (PARAFAC) analysis was used to supplement the routine monitoring in order to reveal more insights into pollutants removal during the leachate treatment by a one-stage partial nitrification-Anammox process (PNA). During this PNA process, up to 96% of total nitrogen and 43% of COD were removed, indicating the potential of PNA process to simultaneously remove nitrogen and organics. Fluorescence intensities and ratios clearly showed the dynamics of influent fluorophores during seasonal variations, where a high amount of protein-like compound was observed during summer months. Protein-like compound was preferentially removed (43-63%) in the PNA process, whereas humic/fulvic-like compounds exhibited recalcitrance to biodegradation. The increase of oxygen supply promoted protein-like compound degradation, which could be associated with the aerobic oxidation pathway. Furthermore, the protein-like compound removal was linearly correlated with the reduction of NH4+-N at limited oxygen conditions (i.e., air flow rate <= 1.6 L-gas/h/L-reactor) = 0.97, n = 65). The fluorescence directly extracted at Ex/Em:230 nm/345 nm was strongly correlated with the biodegradable chemical oxidation demand (BCOD) (r = 0.92, n = 204), showing its high potential as an indicator for biodegradable organics. Given the relatively weak correlation between fluorescence parameters and COD, EEM coupled with multivariate partial least squares (PLS) modeling was proposed and exhibited good predictive power for COD, as exemplified by a mean error of 4.5%

Characterization of landfill leachate by spectral-based surrogate measurements during a combination of different biological processes and activated carbon adsorption

Surrogate measurements based on excitation-emission matrix fluorescence spectra (EEMs) and ultraviolet-visible absorption spectra (UV-vis) were used to monitor the evolution of dissolved organic matter (DOM) in landfill leachate during a combination of biological and physical-chemical treatment consisting of partial nitritation-anammox (PN-Anammox) or nitrification-denitrification (N-DN) combined with granular active carbon adsorption (GAC). PN-Anammox resulted in higher nitrogen removal (81%), whereas N-DN required addition of an external carbon source to increase nitrogen removal from 24% to 56%. Four DOM components (C1 to C4) were identified by excitation-emission matrix-parallel factor analysis (EEM-PARAFAC). N-DN showed a greater ability to remove humic-like components (C1 and C3), while the protein-like component (C4) was better removed by PN-Anammox. Both biological treatment processes showed limited removal of the medium molecular humic-like component (C2). In addition, the synergistic effect of biological treatments and adsorption was studied. The combination of PN-Anammox and GAC adsorption could remove C4 completely and also showed a good removal efficiency for C1 and C2. The Thomas model of adsorption revealed that GAC had the maximum adsorption capacity for PN-Anammox treated leachate. This study demonstrated better removal of nitrogen and fluorescence DOM by a combination of PN-Anammox and GAC adsorption, and provides practical and technical support for improved landfill leachate treatment

In vivo imaging of mitochondrial DNA mutations using an integrated nano Cas12a sensor

Abstract Mutations in mitochondrial DNA (mtDNA) play critical roles in many human diseases. In vivo visualization of cells bearing mtDNA mutations is important for resolving the complexity of these diseases, which remains challenging. Here we develop an integrated nano Cas12a sensor (InCasor) and show its utility for efficient imaging of mtDNA mutations in live cells and tumor-bearing mouse models. We co-deliver Cas12a/crRNA, fluorophore-quencher reporters and Mg2+ into mitochondria. This process enables the activation of Cas12a’s trans-cleavage by targeting mtDNA, which efficiently cleave reporters to generate fluorescent signals for robustly sensing and reporting single-nucleotide variations (SNVs) in cells. Since engineered crRNA significantly increase Cas12a’s sensitivity to mismatches in mtDNA, we can identify tumor tissue and metastases by visualizing cells with mutant mtDNAs in vivo using InCasor. This CRISPR imaging nanoprobe holds potential for applications in mtDNA mutation-related basic research, diagnostics and gene therapies